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S I M P Ó S I O 2 0 1 1
TRANSFERÊNCIA DE CONHECIMENTO E TECNOLOGIA
COVILHÃ, UNIVERSIDADE DA BEIRA INTERIOR15-16 DE DEZEMBRO DE 2011
LIVRO DE ACTAS
Unidade de Materiais Têxteis e Papeleiros
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Reservados todos os direitos
Título:Actas do Simpósio 2011: TRANSFERÊNCIA DO CONHECIMENTO E TECNOLOGIA
UMTP, Universidade da Beira Interior
15-16 de Dezembro de 2011, Covilhã - Portugal
Coordenador da Edição:Manuel José dos Santos Silva
Comissão Organizadora:Manuel José dos Santos Silva
Ana Maria Carreira Lopes
José Mendes Lucas
Rogério Simões
Álvaro Campos Vaz
Madalena Rocha Pereira
Maria José Pacheco
Ana Paula Costa
Carla Sofia Gaiolas
Isabel G. Trindade
Susana Ramos
Comissão Científica:Manuel José dos Santos Silva
Ana Maria Carreira Lopes
José Mendes Lucas
Rogério Simões
Albertina Amaro
Rita Salvado
Dina Mendonça
José Albertino Figueiredo
Ana Maria Ramos
Rui Miguel
Apoio Técnico:Maria da Conceição Camisão
Execução Gráfica:Serviços Gráficos da Universidade da Beira Interior
Tiragem:550 exemplares
ISBN:978-989-654-084-5
Depósito Legal:340785/12
Apoios:
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ÍNDICE
Programa da Conferência / Conference Programme ........................................................................ 9
University and the Transfer of Knowledge and Technology, M. J. Santos Silva .................... 13
Dinâmica da interacção tinta / papel na impressão inkjet, J. L. Amaral, A. P. M. Sousa, N. J.Oliveira, A. O. Mendes, S. C. L. Sousa, P. T. Fiadeiro, A. M. M. Ramos ....................... 18
Steady and Unsteady Bifurcation Flows of Non-Newtonian Inelastic Fluids, H. M. Matos, P. J.Oliveira ................................................................................................................................................. 21
Ultrafiltration and biodegradability of cork processing wastewaters: influence of pH, A. Gomes,L. Silva, R. Simões, N. Canto, A. Albuquerque ......................................................................... 27
Application of electrocoagulation in sanitary landfill leachate treatment, A. Fernandes, D. Norma,M.J. Pacheco, L. Ciríaco, A. Lopes .............................................................................................. 32
Effect of continuous post-setting on crystallinity and thermomechanical behaviour of False-TwistTextured Polylactide multifilaments, A. M. Manich, J. Carilla, D. López-Santana, B. Baena, M.Riba, R Prieto, L. Montero, D. Cayuela ..................................................................................... 34
Sensory Analysis: A New Tool to Characterize Textile Materials, M. E. Cabeço-Silva, C.Nogueira .............................................................................................................................................. 38
Separation of plasmid DNA from non clarified lysate impurities using berenil as ligand in pseudo-affinity chromatography, C. Caramelo-Nunes, M. F. Gabriel, P. Almeida, J. C. Marcos, C. T.Tomaz .................................................................................................................................................... 41
Biodegradability of olive mill wastewaters, L. R. Fernandes, A. Gomes, A. Lopes, R. M. Simões ... 44
Electrochemical degradation of clofibric acid at different anode materials, D. Santos, M. J. Pacheco,A. Gomes, A. Lopes, L. Ciríaco ..................................................................................................... 48
A Perspective on key factors for successful transfer of technology, I. G. Trindade, M. Pereira,R. Miguel, J. Lucas, M. Santos Silva .......................................................................................... 50
Biological activities of Hakea sericea Schrader, Ângelo Luís, Ana Paula Duarte, FernandaDomingues ............................................................................................................................................ 53
Antioxidant activity of phenolic compounds from Prunus avium, S. Santos, J. A. Figueiredo, M.I. Ismael, R. Simões, J. Rodilla, A. P. Duarte ........................................................................... 57
Estudo sobre a distribuição da velocidade do escoamento secundário de um fluido viscoelastico FENE-CR numa curva de secção quadrada, J. M. Malheiro, P. J. Oliveira, F. T. Pinho ................ 59
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Synthesis and characterization of electrically conductive textile/PEDOT samples, I. G. Trindade,C. Gaiolas, J. Lucas, R. Miguel, M. Santos Silva ................................................................... 63
Ionization of AO7 in different ionic media, M. J. R. G. Pires, M. I. A. Ferra, A. Marques ... 67
Nanocrystalline TiO2 films prepared by sputtering for Rhodamine 6G photodegradation: catalytic
efficiency, photo stability and reusability studies, B. Barrocas, O. C. Monteiro, M. E. Melo Jorge,S. Sério ................................................................................................................................................. 70
A Transferência de Conhecimento e Tecnologia na Última Década: Breve Análise de Modelos e Resultados,Madalena Pereira, Isabel Trindade, M.Santos Silva, Rui Miguel, José Lucas ........................ 74
Perovskite thin film electrodes for environmental applications produced by RF-Magnetron Sputtering,S. Sério, A. Costa, Y. Nunes, L. Ciríaco, M. J. Pacheco, A. Lopes, M. I. Pereira, M. E.Melo Jorge ........................................................................................................................................... 81
O efeito conhecimento nas tramas da próxima geração têxtil, Fernando Merino .................. 85
A Intervenção do Design em Causas Humanitárias como o Controlo da Malária, C. Pinheiro, M.J. Geraldes, R. Gomes ...................................................................................................................... 89
Development of a cap to support the mobility of visually disabled people, N. Nascimento, R. Salvado,F. Borges, P. Araújo ......................................................................................................................... 93
Modelização da resistência à abrasão de tecidos de lã e poliéster em função das característicasestruturais de fios convencionais, N. Monteiro, R. Miguel .......................................................... 96
POSTERS
Indocarbocyanine Supports for Protein Separation, D. Almeida, F. Sousa, P. Almeida, R. E. F.Boto ..................................................................................................................................................... 103
Novos suportes para cromatografia de afinidade por síntese total de cianinas na matriz cromatográfica.Avaliação da contribuição de cada uma das partes na afinidade ligando-proteína, L. P. Alves, S.S. Ramos, R. E. F. Boto, P. Almeida .......................................................................................... 106
Synthesis of New α-Methylene-γ-Lactones Linked to Ferrocene Derivatives, J. Albertino Figueiredo,Carlos Anjo, Rita Pereira, M. Isabel Ismael, Ivânia Cabrita, Ana C. Fernandes ...........110
Total phenol content in solvents extracts of Lavandula luisieri, João Araújo, Fernanda Delgado,Jesus Rodilla, Arlindo Gomes, Lúcia Silva ................................................................................. 111
Triterpene glycosides from Piliostigma thonningii, L. I. N. Canelo, D. I. Mendonça1, N. Fernandes,R. S. Mata ..........................................................................................................................................113
Synthesis, characterization and antioxidant activity of Thio-imidate N-oxides (TIO) sugars, M.Domingues, M. I. Ismael, J. A. Figueiredo, M. Schuler, P. Rollin, A. Tatibouët ..............114
Synthesis of monolithics supports for affinity chromatography, N. Esteves, C. Canário, P. Almeida,M. J. Nunes .......................................................................................................................................115
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Anodic oxidation of Acid Red 88 on a BDD electrode, A. D. Fonseca, P. Luz, L. Ciríaco, M.J. Pacheco, A. Lopes .......................................................................................................................117
Aplicação do catalisador Cu-TiO2 na fotodegradação de uma amina aromática, J. Matos, A. Santos,
M. Magrinho, J. Lucas ...................................................................................................................119
Steady and Unsteady Bifurcation Flows of Non-Newtonian Inelastic Fluids, H. M. Matos, P. J.Oliveira ............................................................................................................................................... 121
Characterization of a leachate from a sanitary intermunicipal landfill. Analysis of the content inmetals at several stages of the wastewater treatment plant, E. Mestrinho, V. Ribeiro, A. P. Pinto,M. E. Lopes ...................................................................................................................................... 127
Lamellar monomethynecyanines-doped mono-amidosil hybrids, S. C. Nunes, J. Hümmer, R. A. SáFerreira, L. D. Carlos, P. Almeida, V. de Zea Bermudez ...................................................... 129
Bioconversion of lignocellulosic residues into biogas, R. Oliveira, A. Mendonça, I. Gonçalves,H. M. Pinheiro, M. I. Ferra ......................................................................................................... 132
Ionization of Acid Orange 8, V. M. B. Pinto, M. J. R. G. Pires, M. I. A. Ferra, A. Marques ... 134
Preparação de derivados de esqueleto guaieno a partir de Guaiol e Bulnesol, Sofia Pombal, JesusRodilla, Lúcia Silva ......................................................................................................................... 136
Trihalomethanes in wastewaters and risk for aquatic environment, A. S. Rebelo, T. A. Anágua,M. I. A. Ferra, A. Marques .......................................................................................................... 138
New N-carboxyalkylthiacarbocyanine dyes functionalized with amino derivatized groups as ligandsin dye-affinity chromatography, T. E. Silva, P. Almeida, R. E. F. Boto ................................. 140
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PROGRAMA DA CONFERÊNCIA / CONFERENCE PROGRAMME
Thursday, 15 December
09.00 - 09.30 Registration, Anfiteatro 8.1, Faculty of Engineering
09.30 - 10.00 WELCOME SESSION AND PRESENTATION OF THE RESEARCH UNITOF TEXTILE AND PAPER MATERIALSAna Paula Coelho Duarte, Vice-Rector for Research and Innovation andCoordinator of the Research InstituteManuel José dos Santos Silva, Coordinator of the MTP research unit
10.00 - 13.00 SESSION IChairpersons: Rogério Simões and Ana Lopes
10.00 - 10.30 A UBI e o empreendorismoAna Paula DuarteICI, Universidade da Beira Interior
10.30 - 11.00 Dinâmica da interacção tinta / papel na impressão inkjetLuís Amaral2, António Mendes de Sousa2, Nuno Oliveira2, António Mendes1, SóniaSousa1, Paulo Fiadeiro1, Ana Ramos1
1 MTP Unit, University of Beira Interior, 6201-001 Covilhã, Portugal2 RAIZ - Institurte of Forest and Paper Research, Apartado 15, 3801-501 Eixo, Portugal3 Grupo Portucel-Soporcel
11.00 - 11.30 Coffee Break and Poster Session
11.30 - 11.45 Steady and Unsteady Bifurcation Flows of Non-Newtonian Inelastic FluidsHélder Matos, Paulo OliveiraUMTP, Departamento de Engenharia Electromecânica, Universidade da Beira Interior, Portugal
11.45 - 12.00 Ultrafiltration and biodegradability of cork processing wastewaters: influence of pHA. Gomes1, L. Silva1, R. Simões1, N. Canto1, A. Albuquerque2
1 UMTP and Department of Chemistry, University of Beira Interior2 Department of Civil Engineering and Architecture, University of Beira Interior, 6201-001Covilhã, Portugal
12.00 - 12.15 Application of electrochemical methods in sanitary landfill leachate treatmentA. Fernandes, D. Norma, M. J. Pacheco, L. Ciríaco, A. LopesUMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal
12.15 - 13.00 Discussion
13.00 - 15.00 Lunch at the Great Hall of the Faculty of Engineering and Poster Session
15.00 - 18.30 SESSION IIChairpersons: José Lucas and Madalena Pereira
15.00 - 15.30 Effect of continuous post-setting on crystallinity and thermomechanicalbehaviour of False-Twist Textured Polylactide multifilamentsA. M. Manich¹, J. Carilla¹, D. López-Santana¹, B. Baena¹, M. Riba², R Prieto²,L. Montero², D. Cayuela2
¹ IQAC-CSIC, Barcelona (Spain)² INTEXTER-UPC, Terrassa (Spain)
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15.30 - 16.00 Sensory Analysis: A New Tool to Characterize Textile MaterialsM. E. Cabeço-Silva, C. NogueiraCentro de Ciência e Tecnologia Têxtil, Universidade do Minho, Guimarães, Portugal
16.00 - 16.30 Coffee Break
16.30 - 16.45 Separation of plasmid DNA from non clarified lysate impurities using berenilas ligand in pseudo-affinity chromatographyC. Caramelo-Nunes1,2, M. F. Gabriel1,2, P. Almeida1,2, J. C. Marcos3, C. T. Tomaz1,2
1 CICS-UBI – Health Sciences Research Centre, University of Beira Interior, 6201-001 Covilhã,
Portugal2 Department of Chemistry, University of Beira Interior, Covilhã, Portugal3 Centre of Chemistry, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
16.45 - 17.00 Biodegradability of olive mill wastewaterLuís Roberto Fernandes, Arlindo C. Gomes, Rogério S. SimõesUMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal
17.00 - 17.15 Electrochemical degradation of clofibric acid at different anode materialsD. Santos1, M. J. Pacheco1, A. Gomes2, A. Lopes1, L. Ciríaco1
1 UMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal2 CCMM, Department of Chemistry and Biochemistry, University of Lisbon, Lisboa, Portugal
17.15 - 17.30 A Perspective on key factors for successful transfer of technologyI. G. Trindade1,2, M. Pereira1,2, R. Miguel1,2, M. Santos Silva1,2
1 Unidade de Materiais Têxteis e Papeleiros, Rua Marquês D´Ávila e Bolama, 6201-001 Covilhã,
Portugal2 Departamento de Ciência e Tecnologia Têxteis, Universidade da Beira Interior, 6201-001
Covilhã, Portugal
17.30 - 18.00 Discussion
18.00 - 18.30 Poster Session
Friday, 16 December
09.30 - 13.00 SESSION IIIChairpersons: Dina Mendonça, Paulo Oliveira, Hélder Matos and Elmina Lopes
09.30 - 09.45 Biological activities of Hakea sericea SchraderÂngelo Luís, Ana Paula Duarte, Fernanda DominguesCICS-UBI Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã
09.45 - 10.00 Antioxidant activity of phenolic compounds from Prunus aviumS. Santos1, J. A. Figueiredo1, M. I. Ismael1, R. Simões1, J. Rodilla1, A. P. Duarte2
1 UMTP and Department of Chemistry, University of Beira Interior, Covilhã, Portugal2 CICS, Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
10.00 - 10.15 Estudo sobre a distribuição da velocidade do escoamento secundário deum fluido viscoelástico FENE-CR numa curva de secção quadradaJoana M. Malheiro1, Paulo P. Oliveira1, Fernando T. Pinho2
UMTP, Departamento de Engenharia Electromecânica, Universidade da Beira Interior,
Portugal
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10.15 - 10.30 Synthesis and characterization of electrically conductive textile/PEDOTsamplesI. G. Trindade1,2, C. Gaiolas1,2, J. Lucas1,2, R. Miguel1,2, M. Santos Silva1,2
1 Unidade de Materiais Têxteis e Papeleiros, Rua Marquês D´Ávila e Bolama, 6201-001 Covilhã,Portugal2 Departamento de Ciência e Tecnologia Têxteis, Universidade da Beira Interior, 6201-001Covilhã, Portugal
10.30 - 11.00 Coffee Break and Poster Session
11.00 - 11.15 Ionization of Acid Orange 7 in Different Ionic MediaM. J. R. G. Pires, M. I. A. Ferra, A. M. M. M. B. AmaroChemistry Department, University of Beira Interior, 6201-001 Covilhã
11.15 - 11.30 Risk assessment of water resourcesA. S. Rebelo1, M. I. A. Ferra2, A. M. M. M. B. Amaro2, I. M. S. C. Gonçalves2
1 Adm. Região Hidrog. Algarve2 Chemistry Department, University of Beira Interior, 6201-001 Covilhã
11.30 - 11.45 A transferência de conhecimento e tecnologia na última década: breve análisede modelos e resultadosMadalena Pereira1,2, Isabel Trindade1, M.Santos Silva1,2, Rui Miguel1,2, José Lucas1,2
1 Unidade de Materiais Têxteis e Papeleiros2 Departamento de Ciência e Tecnologia Têxteis, Universidade da Beira Interior, 6201-001Covilhã, Portugal
11.45 - 12.00 Perovskite thin film electrodes for environmental applications produced byRF-Magnetron SputteringS. Sério1, A. Costa2, Y. Nunes1, L. Ciríaco3, M. J. Pacheco3, A. Lopes3, M. I.Pereira2, M. E. Melo Jorge2
1 CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia da UniversidadeNova de Lisboa, 2829-516 Caparica, Portugal2 CCMM, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidadede Lisboa, Campo Grande, 1749-016 Lisboa, Portugal3 Departamento de Química, UMTP, Universidade da Beira Interior, 6201-001 Covilhã,Portugal
12.00 - 12.15 NanocrystallineTiO2 films prepared by sputtering for Rhodamine Gphotodegradation: catalytic efficiency, photo stability and reusability studiesB. Barrocas1,2, O. C. Monteiro2, M. E. Melo Jorge2, S. Sério1
1 CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia da UniversidadeNova de Lisboa, 2829-516 Caparica, Portugal2 CCMM, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidadede Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
12.15 - 13.00 Discussion
13.00 - 15.00 Lunch at the Great Hall of the Faculty of Engineering and Poster Session
15.00 - 17.00 SESSION IVChairpersons: Rui Miguel and Rita Salvado
15.00 - 15.30 O efeito do conhecimento nas tramas da próxima geração têxtilFernando MerinoCentro Tecnológico das Indústrias Têxtil e do Vestuário de Portugal – CITEVE
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15.30 - 16.00 Eco Textile DevelopmentsJames MendoliaA. A. S. Fashion Marketing, Parsons The New School for Design, New York, USA
16.00 - 16.15 A Intervenção do Design em Causas Humanitárias como o Controlo da MaláriaC. Pinheiro1,2, M. J. Geraldes1,2, R. Gomes3
1 Unidade de Materiais Têxteis e Papeleiros, 6201-001 Covilhã, Portugal2 Departamento de Ciência e Tecnologia Têxteis, Universidade da Beira Interior, 6201-001Covilhã, Portugal3 Departamento de Engenharia Têxtil - Universidade do Minho, Guimarães, Portugal
16.15 - 16.30 Desenvolvimento de um boné para apoio à mobilidade de deficientes visuaisN. Nascimento1,2, R. Salvado1,2, F. Borges3, P. Araújo4
1 Unidade de Materiais Têxteis e Papeleiros, 6201-001 Covilhã, Portugal2 Departamento de Ciência e Tecnologia Têxteis, Universidade da Beira Interior6201-001 Covilhã,Portugal3 Instituto Federal de Educação, Ciência e Tecnologia da Paríaba, Brasil4 Universidade da Beira Interior- Instituto de Telecomunicações
16.30 - 16.45 Modelização da resistência à abrasão de tecidos de lã e poliéster em funçãodas características estruturais de fios convencionaisN. Monteiro, R. MiguelUnidade de Materiais Têxteis e Papeleiros e Departamento de Ciência e Tecnologia Têxteis,Universidade da Beira Interior 6201-001 Covilhã, Portugal
16.30 - 17.00 DISCUSSION and FINAL SESSIONChairpersons: Manuel Santos Silva, Ana Lopes, José Lucas and Rogério Simões
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University and the Transfer of Knowledge and Technology
M.J. Santos Silva1
1University of Beira Interior Unit of Textile and Paper Materials
Abstract
This article traces the dynamic evolution of the Portuguese and European university through the historical journey from the Renaissance of the twelfth century to the present day, with special emphasis on the most recent of its functions, the so-called third mission, which includes the connection to society, diffusion and transfer of knowledge and technology and their economic value. As an example of knowledge transfer, innovations developed in the Unit of Textile and Paper Materials at the University of Beira Interior are presented.
Introduction
The first universities emerged in medieval Europe during the Renaissance of the twelfth century. However, a broader perspective may lead us to the Academy, founded in 387 BC by the Greek philosopher Plato in the grove of Acadia, near Athens. The Academy can be understood in some way, as a precursor of the university. In it, students were taught philosophy, mathematics and gymnastics, however it did not constitute a real university because each thinker founded a school to pass on or transfer his own knowledge and not to discuss them. Only in the Middle Ages universities were established by the Catholic Church. There, students were taught disciplines related to faith, as theology, philosophy and languages.
The first European universities were founded in Italy and France to study law, medicine and theology. But before that, similar institutions existed in the Islamic world, the most famous being that of Cairo. In Asia, the most important institution of higher education was Nalanda, in Bihar, India, where the Buddhist philosopher Nagarjuna lived, in the second century.
In Europe, the boys were heading to university after completing the study of the trivium: the preparatory arts of grammar, rhetoric and logic or dialectics, and the quadrivium: arithmetics, geometry, music and astronomy. After that, the student could pursue more specific studies.
The University in Portugal
By signing the "Scientiae thesaurus mirabilis", Portuguese King Dinis founded the first university in Portugal and one of the oldest in the world in continuous operation.
Dating from 1290, the document gives rise to the
recognized in the same year by Pope Nicholas IV. When, in 1288, the prelates of Loulé, Santa Cruz de Coimbra and other religious houses and churches asked the Pope to confirm their willingness to allocate part of their income to the , the European university movement had already completed its early stage, charismatic and innovative, in which the University would represent one of the most prodigious engines of intellectual renewal of medieval Europe, with universities such as Paris, Bologna and Oxford. A century after the birth of the nation, thus germinated the University of Coimbra, which began operating in Lisbon in 1308 and was transferred to Coimbra, alternating between the two cities until 1537, when it was settled permanently in the city of the Mondego River [1].
The University of Lisbon was established on March 22, 1911, by decree of the Provisional Government of the Portuguese Republic, together with the University of Porto, in order to put the two largest cities in the same situation as Coimbra. To this end, new academies were founded and higher education schools were merged in faculties. The education reform undertaken by Professor Veiga Simão, in 1973, democratized higher education in Portugal, creating a set of universities and polytechnics to cover almost the entire country. Also at this time it was created the Polytechnic Institute of Covilhã, which started its academic activities on 17 February 1975, by teaching the courses of Textile Engineering and Management and Accounting, in order to meet the needs of qualified staff to local industry. Thus was born the institution that is now the University of Beira Interior.
Higher education in Portugal had a great development and growth in number of students after the April Revolution of 1974 to the present day.
The third mission of the university
As already mentioned, the medieval universities were founded around 1150 in the context of the Renaissance of the twelfth century. These institutions were the starting point for the model of university that lasted until the twentieth century. They were not just educational institutions but also places of research and knowledge
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production, and also foci of many vigorous debates and controversies, as evidenced by the successive crises in which these institutions were involved and by the many interventions that they have suffered from the political and ecclesiastical power.
European universities, with a strong influence of its medieval roots, were primarily educational institutions, whose primary purpose or mission was the dissemination and transmission or transfer of knowledge. Only in the late nineteenth, early twentieth century, research came to be regarded as a task of academics within the universities [2]. This dual mission of teaching and research has become conventional and generalized to all university systems.
However, this almost unquestionable model of teaching and research has been transformed over time and eventually would be affected by a new dynamic, which can be considered as the second revolution in the structure or mission of the university and which ultimately give it a third mission.
In essence, a revolution has been promoted by public policies, which resulted in a process of transformation of universities, considered authentic ivory towers, into institutions more connected and engaged with society and its economic development through the transfer of knowledge and knowledge they generate. Through the formalization of this mission, the universities have become the true engine of the knowledge economy [3]. Working closely with industry on the part of universities or of its elements is not new and had different developmental stages at different times and regions of the globe, but the commitment to society, through the formalization of public policy, is quite recent - two to three decades.
The United States of America are usually mentioned as a model of cooperative university / industry. Although they have led this revolution, through the publication of specific legislation, this only happened in 1980, with the publication of the "Bayh-Dole Act" or Patent and Trademark Law Amendments Act. [4]. Through this document, Bayh-Dole Act, the U.S. Government encourages universities to participate and promote technology transfer and commit themselves to actions of entrepreneurial character, by giving them the power to control or market their inventions and rights of intellectual property, under various forms, resulting from federal government-funded research. This business nature revolution was led by the Massachusetts Institute of Technology and the Universities of Stanford, Harvard and California [5], which took the strategy of emphasizing applied research, under the most different forms. Technology transfer led the strategy of intensive research universities and the aforementioned legislation triggered a
growth and a trend in universities, in general, to seek opportunities for business or commercial nature. Considering the success of the strategies defined and followed upon the publication of Bayh-Dole Act, this revolution was followed by the governments of different countries worldwide during the last decades, promoting atypical practices in universities that eventually become perfectly normal [6] .
Given its cultural proximity, the United Kingdom immediately adopted similar policies, pursuing comprehensive reforms in academia. Since 1985 the university had the right to register and commercialize research results produced by its members and in the 90's several documents appeared identifying the socio-economic commitment by universities.
The publication of legislation on financing, including the creation of a line through the Higher Education Funding for England (HEFCE) in 1999, formalized the emergence of the third mission of the university in the UK,
The entrepreneurial university
Recognizing the problems of the declining public funding [8] European universities have been encouraged to look at the technology markets and to seek alternative sources of funding, registering its inventions and developments [9]. Between 2000 and 2002, for example, Germany, Austria and Denmark abolished the so-called privileges of teachers [10], in order to increase the number of patents registered on behalf of the universities. In France [11], the Napoleonic university suffered and has been undergoing strong transformations under strong criticism on the public research system considered unable to transfer the results to industry. From the last decade of the twentieth century there was a change in political climate that has resulted in an effort of the universities to have a better control over intellectual property rights and inventions of its members. Portugal, as might be expected, also experienced dynamic change in universities. If the University Autonomy Law, Law 108/88, gave full powers to universities and the ability to manage its own revenues, the Legal Regime of Higher Education Institutions, Law 62/2007, dated September 10, enshrined the connection of the university to society as well as the encouragement and the right to transfer scientific knowledge and technology and their economic value. Article 2 of this Law, Mission of Higher Education, over its five paragraphs, establishes what traditionally is considered as teaching and learning, knowledge creation and research, but it reinforces the concept that we are calling the third mission of the university: the connection to society, the dissemination
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and transfer of knowledge and technology and their economic value.
The debates on the transformation of the mission of the University in relation to its medieval and traditional conception extended across Europe [12] creating instruments that would allow and encourage a more enterprising character of higher education institutions and their socio-economic accountability to society. However, European universities have never been as effective in marketing the product of their research as the U.S.. A study on OECD countries (OECD, 2007) [13] shows that in spite of the the strategies of public policy, the transition to the entrepreneurial university, despite being underway worldwide, is occurring at different speeds, and that success rates vary widely from country to country or even from institution to institution.
The European Commission has made huge political, legislative and financial efforts towards making Europe the most competitive economy in the world through the knowledge generated and transferred. The Lisbon Treaty, signed in 2000, predicted that this would happen in 2010, thanks to the efforts and investment in education, research, innovation, in short, the transfer of knowledge and technology for enterprises, which are the real creators of wealth. However, when compared with the U.S., investment in education and research, particularly private investment, is still an underlying problem. Despite successive targets, Europe is still far from the U.S. and Japan and witness a strong growth in China.
In 2011, the European Commission published a new document "Europe 2020 Flagship Initiative - Innovation Union" [14], which makes another reference to budgetary constraints and under-investment in knowledge, in less than 0.8% of GDP that the U.S. and 1.5% less than Japan. However, it is recognized that with the ongoing worldwide changes, with the steady growth of competitiveness and the need to create new jobs to compensate those lost with the crisis we are experiencing, if we want to maintain our way of living and well-being in the future this will depend on our ability to introduce innovation in products, services, business processes and social patterns. Thus, innovation is the heart of strategic development for Europe in 2020.
Recognizing the potential and values of Europe, qualified human resources, culture, traditions, creativity and diversity, several requirements must be complied, which are related to investment in education, research and innovation. It is necessary that research leads to greater innovation and a better cooperation among the worlds of science, industry, agriculture and business cooperate, removing any obstacles. To drive innovation we must strengthen the components of design and creativity and promote a better understanding of the public sector. Internationalization must be promoted and partnerships improved, giving working conditions for researchers to
prevent their escape from the country, but taking appropriate measures in order to protect the interests of Europe.
It is planned, which should have been already reached, that in 2020 3% of European GDP should be invested in R&D and that this could create 3.7 million jobs and an annual GDP growth of around 800 billion euros, around 2025. The European Commission says it is absolutely necessary to make the "Innovation Union" a reality.
We must be cautious because it is difficult to imagine a homogenization of the universities in the area of higher education at European level, taking into account that research is what distinguishes universities from institutions of higher education. However, the third mission, in essence dominated by technology transfer, has to do with different forms of managing or commercializing knowledge. Patenting the formation of spin-offs and licensing may lead to a wide variety of activities for the enhancement of knowledge. Although the areas of biotechnology, health, computer science, engineering, physics and chemistry are the ones that lead to increased transfer activities, being more developed in research-intensive universities, they are not exclusive to this mission of the university, which also widened to the arts, social sciences and humanities, leading also to certain competitiveness between institutions.
The third mission of the university [15], the transfer of knowledge and technology, also has the ability to stimulate, develop, consolidate and specialize teaching through the development of research in their respective areas, which is fundamental to a quality education. Of course there is always the question of basic research, which seems to present more difficulties in its economic recovery, but nowadays research has no borders, it became international through the contacts of scientists in different areas.
Research becomes increasingly pluridisciplinar. Basic science and cultural base areas, such as philosophy, are increasingly present in various research groups. Our unit is an example of the link between Exact Sciences and Engineering. The connection to enterprises, either by placing students in graduate school, or by developing joint programs or even the passage of researchers by companies during a sabbatical, allows better placement of students, a better transfer of knowledge and an improvement in teaching and research.
To promote and encourage entrepreneurship and technology transfer, Universities have been creating their own structures of support, as offices of technology transfer and even space for business incubation, in partnership with other institutions, Science and Technology Parks, Business Innovation Centres and other structures for the incubation of ideas and technologies generated in / in partnership with the structures and
16
members of the university. But it is not enough to create these structures, we must give them support and integrate them in the processes and culture of the university, while promoting synergies between the three main missions of the university, to promote the institution as a whole and demonstrate that the third mission complements and adds value to teaching and research.
The universities of our time, a time of crisis, are under strong pressure, not only from society, but also from the political means, hoping that they open up and contribute effectively to create wealth through the knowledge they generate and its transfer to society. In fact, today we live in a knowledge society and it is hoped that with the entrepreneurial and commercial aspect, the universities generate revenue to help support education and research activities, relieving the public purse.
It is more than assumed today that university has three core missions: teaching, research and cooperation with society at many different levels, including the transfer of knowledge and technology. However, we must always bear in mind that the Professor/Researcher is at the center of the process and we must understand his/her motivations for the development of science, as well as for decision making about the protection of intellectual property, providing the necessary information to prepare interventions that will take to the process of technology transfer, which could lead to wealth creation and economic development.
The university as a development factor
Universities contribute to the development of humanity under the most different ways, apart from regional, national or worldwide economic development. New knowledge is transferred to industries, enterprises or institutions and applied in creating new products, processes or services that lead to innovation and wealth creation. But we must not forget the culture that emanates from the institution itself and leads to the transformation of the surrounding society, making it difficult to socially, culturally and economically quantify this aspect.
Take, for example, what happened to the Cova da Beira, and particularly to Covilhã, with the creation and development of the University of Beira Interior. Covilhã, a city mill, the "Portuguese Manchester", with well-defined class of industrialists, some skilled technicians and a huge working class, with a very low level of education, becomes, in three decades, a university town, contributing with the best rate of graduates at the national level, taking into consideration the population and the birth rate in the region. The laborers, that not long ago crossed the narrow streets on their way from factories planted along the streams of Degoldra and Carpinteira, whose water quality has allowed the installation and development of the wool industry, in addition to the use
of the driving force due to flow and steep slopes, gave rise to a much higher number of students circulating through these same streets. Apart from students, about seven thousand, there are more than six hundred teachers and researchers and four hundred employees at the university. From the ruins of the factories, recovered and renovated spaces emerged, with classrooms, libraries and laboratories where research is produced and knowledge is created and transferred.
The Polytechnic Institute of Covilhã (IPC), the University Institute of Beira Interior (IUBI), the University of Beira Interior (UBI), the R & D Unit of Textile and Paper Materials (MTP)
There is no evolution without history. The IPC was created in Covilhã because here there was a woolen industry in need of qualified staff, which could make it evolve technologically in the frame of the industrial revolution taking place across the world. Since the beginning the young institution had a concern of connection to society at a local, national and international level. The same happened to textile and paper sectors.
Right in the beginning there was already a concern for fundamental and applied research. Some members of the Unit of Textile and Paper Materials were the protagonists of this adventure. In the early 80s, there was already transfer knowledge and technology as exemplified by the patents (U.S. Patents: No. 75790: "Method and device for measuring the parallel textile fibers"; No. 75791, "Method and device for measuring the hairiness of yarns", No. 89437, "Method of measuring the entropy of textile products") and especially the industrial achievements that have given rise to such equipment:
"Robot cutting tissue laser," the tear "Lucas" and many other projects with industry, such as "The measure of energy consumption in the textile industry", the "ozone-Blanching folder" etc.
With the passage of IUBI to UBI in 1986, the dynamic growth of scientific production became more marked and so our unit arises in 1991, with all these well-known achievements, which are its main actors. We can say that our University and our unit encouraged, over time, the three missions of the University, with particular emphasis on transferring knowledge and technology. In short, what is now called entrepreneurship has always been the flagship of the institution that is known as the University of Beira Interior.
References
1. Volume I, Tomo I, (1290-1536). Universidade de Coimbra e Fundação Calouste Gulbenkian, 1997.
17
2.
3. Economic -25,
2001.
4. -Dole Act of 1980 and university-industry technology transfer: a
The Journal of Technology Transfer, Vol.30 Nrs. 1,2, 115-27, 2005.
5. quasi-firms: the
Policy, Vol.32, Nr. 1, pp. 109-21, 2003.
6. nd
7. Today, Vol.6, Nr. 6, pp.50-5, 2003.
8. university research funding: are there negative unintended
Journal of Economic Issues, 35: 607-32, 2001.
9. effects on academic research: the emerging European
-807, 2006.
10. Lissoni, F., Llerena, P., Mckelvey, M., Sanditov, B.,
-102, 2008.
11. Change and Academic Patenting: French Universities and
-Università Bocconi, Working Paper, nr. 29, 2010.
12. Rothaermel, F.T., Agung, S.D. and Jiang, L., e
Industrial and Corporate change, Vol. 16, Nr. 4, pp. 691-791, 2007.
13. Competitive, Locally Engaged, OECD, Paris, 2007.
14. -92-79-17688-3,
Publications Office of the European Union, Luxembourg, 2011.
15. engaging and embedding the third mission in
Sociology and Social Policy, Vol. 30, Nr. 7/8, pp. 341-353, 2010.
18
Dinâmica da interacção tinta / papel na impressão inkjet
J. L. Amaral3, A. P. M. Sousa3, N. J. Oliveira4, A. O. Mendes1, S. C. L. Sousa1, P. T. Fiadeiro1,2, A. M. M. Ramos1
1Unidade de Materiais Têxteis e Papeleiros, Universidade da Beira Interior, 6201-001 Covilhã, Portugal
2Unidade de Detecção Remota, Universidade da Beira Interior, 6201-001 Covilhã, Portugal
3RAIZ Instituto de Investigação da Floresta e Papel, Apartado 15, 3801-501 Eixo, Portugal
4Grupo Portucel-Soporcel, Lavos Apartado 5, 3081-851 Figueira da Foz, Portugal
Resumo
Neste trabalho são apresentados dois sistemas ópticos experimentais que foram desenvolvidos e implementados, no Centro de Óptica da Universidade da Beira Interior, para o estudo dos fenómenos da interacção tinta / papel na impressão inkjet. O primeiro sistema foi desenvolvido especificamente para o estudo da dinâmica da interacção da tinta na superfície do papel. O segundo sistema, por outro lado, foi desenvolvido especificamente para o estudo da penetração da tinta no interior da estrutura do papel usando as mesmas amostras analisadas através do primeiro sistema.
Introdução
O desenvolvimento de novos papéis que ofereçam um desempenho e uma qualidade de impressão cada vez melhores é uma questão que sempre interessou e continua a interessar à indústria papeleira. Esta questão torna-se especialmente pertinente no caso da impressão inkjet devido à sua grande utilização e popularidade, tendo exibido um crescimento exponencial nos últimos anos. Por estes motivos, muitos trabalhos de investigação relacionados especificamente com a temática da impressão inkjet foram e continuam a ser levados a cabo por diversos grupos de investigação no sentido de melhor se perceberem as interacções envolvidas entre as tintas e os papéis com o objectivo de melhorar a qualidade final da impressão [1-10].
No que respeita às interacções que ocorrem entre as tintas e os papéis, elas dependem das propriedades físico-químicas tanto das tintas como dos papéis e também do próprio método de impressão [11, 12]. Em relação à avaliação da qualidade de impressão, esta é geralmente feita por intermédio de sistemas de aquisição de imagens, em condições controladas, e pela medição de diversos parâmetros nas imagens registadas. Exemplos destes
dos pontos, a densidade óptica de impressão e a área [4, 13-15].
Existem, contudo, ainda outros parâmetros de extrema importância para avaliação da qualidade final da impressão e que têm obrigatoriamente de ser quantificados não só após a impressão estar concluída,
mas também durante o período de tempo em que é feita a própria deposição da tinta na superfície do papel. Tais parâmetros compreendem a análise dinâmica ou, por outras palavras, a análise ao longo do tempo do volume da gota de tinta, da altura da gota de tinta, dos diâmetros base, dos ângulos de contacto e da área de espalhamento. Adicionalmente, é também importante conhecer de que forma ocorreu a penetração da tinta no interior da estrutura do papel após a deposição da gota de tinta, e qual a penetração máxima que foi atingida. Em particular, alguns estudos têm sido realizados no sentido de avaliar o efeito da penetração das tintas sobre a capacidade de reprodução de cor [2, 6, 16, 17].
Tendo em atenção as ideias expostas e com vista a fornecer um contributo positivo à indústria papeleira no que se refere a avaliação da qualidade de impressão, foram desenvolvidos e implementados, no Centro de Óptica da Universidade da Beira Interior, dois sistemas ópticos experimentais para estudo dos fenómenos da interacção tinta / papel na impressão inkjet. O primeiro sistema foi desenvolvido especificamente para o estudo da dinâmica da interacção da tinta na superfície do papel. O segundo sistema, por outro lado, foi desenvolvido especificamente para o estudo da penetração da tinta no interior da estrutura do papel usando as mesmas amostras analisadas através do primeiro sistema.
Material e Métodos
No primeiro sistema óptico experimental desenvolvido para o estudo dos fenómenos da interacção tinta / papel, em particular, são usados três detectores de imagem para registar, em simultâneo, imagens segundo três vistas distintas de uma gota de tinta que é formada e ejectada sobre a superfície de uma amostra de papel. As vistas registadas do evento correspondem a duas laterais e perpendiculares entre si, e a uma outra de topo. O evento é registado durante alguns segundos, normalmente 10 segundos ou menos, a uma taxa de mais de 200 imagens por segundo. Através do processamento das imagens registadas do evento em estudo, é possível criar um modelo tridimensional da interacção da gota de tinta na superfície do papel para cada instante de tempo, e também determinar os principais parâmetros envolvidos nessa mesma interacção, tais como o volume da gota de tinta, a sua altura, diâmetros base, ângulos de contacto e a área de
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espalhamento. A figura 1 mostra uma fotografia geral do sistema óptico experimental desenvolvido para estudo da interacção da tinta na superfície do papel, sendo visíveis os principais elementos que compõem o sistema.
Figura 1 Fotografia geral do sistema óptico experimental desenvolvido para estudo da interacção da tinta na superfície do papel.
Relativamente ao segundo sistema óptico experimental desenvolvido para estudo dos fenómenos da interacção tinta / papel na impressão inkjet, um único detector de imagem é usado para registar imagens ampliadas das secções das amostras de papel que foram analisadas com o sistema anterior. Essas amostras são inicialmente cortadas e posteriormente embebidas em parafina para poderem ser convenientemente seccionadas e assim se obterem os vários perfis de penetração ao longo de toda a extensão da mancha de tinta formada. O seccionamento das amostras de papel é feito recorrendo ao uso de um micrótomo, usando um passo de aproximadamente 50 micrómetros. Seguidamente, para cada secção, é registada uma imagem evidenciando a penetração da tinta na espessura do papel. Através da combinação da totalidade das imagens registadas é também possível criar um modelo tridimensional da penetração da tinta no interior da estrutura do papel, e também determinar a penetração máxima que foi atingida pela gota de tinta. A figura 2 mostra uma fotografia geral do sistema óptico experimental desenvolvido para estudo da penetração da tinta no interior da espessura do papel, sendo visíveis os principais elementos que compõem o sistema.
Figura 2 Fotografia geral do sistema óptico experimental desenvolvido para estudo da penetração da tinta no interior da estrutura do papel.
Para controlo de todos os processos de aquisição, armazenamento e processamento das imagens registadas através de ambos os sistemas ópticos experimentais desenvolvidos, foram implementados vários aplicativos de software usando a linguagem de programação MatLab e as Toolboxes de aquisição e processamento de imagem.
Conclusões
Ambas as metodologias ópticas descritas neste artigo foram aplicadas a um largo conjunto de tintas e papéis e permitiram constatar que cada combinação tinta / papel apresenta resultados muito singulares e característicos. Os parâmetros determinados para essas mesmas combinações acompanham e mostram ser concordantes com as análises qualitativas que podem ser realizadas por observação directa das imagens adquiridas. Assim, ambas as metodologias ópticas descritas mostram ser uma mais-valia em termos de controlo de qualidade na análise do processo de impressão inkjet visto que permitem quantificar objectivamente parâmetros importantes da interacção tinta / papel, sendo também importantes na identificação de determinados comportamentos exibidos pelas tintas e papéis. Em suma, ambas as metodologias apresentadas parecem ser importantes para análise e avaliação da impressão inkjet sugerindo um grande potencial para adaptação em protótipos laboratoriais podendo, no futuro, ser usados numa prática corrente no sector papeleiro. O trabalho desenvolvido constitui assim mais um exemplo de sucesso em termos de transferência de conhecimento e tecnologia por parte da Unidade de Materiais Têxteis e Papeleiros da Universidade da Beira Interior, com aplicação prática no sector da indústria.
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Referências
1. Koskela, J.P. and O.E.O. Hormi, Improving the printability of paper with long-chain quaternaries. Appita Journal, 2003. 56(4): p. 296-300.
2. Yang, L., Ink-paper interaction: A study in ink-jet color reproduction, Linköping Studies in Science and Technology: Dissertations N.º 806, in Department of Science and Technology. 2003, Linköping University. p. 1-149.
3. Moutinho, I.M.T., P.J.T. Ferreira, and M.L. Figueiredo, Impact of Surface Sizing on Inkjet Printing Quality. Industrial & Engineering Chemistry Research, 2007. 46(19): p. 6183-6188.
4. Mendes de Sousa, A.P., et al. Estudo da Interacção Tinta-Papel em Impressão Inkjet. in 20th Tecnicelpa Conference and Exhibition. 2007. Tomar, Portugal.
5. Varnell, D.F., Surface Sizing with Sizing Agents and Glycol Ethers - Patent US 2008/0163993 A1. 2008: USA.
6. Pauler, N., O. Norberg, and P. Edström. Mechanisms involved in the optical interaction between ink and substrate for Home&Office inkjet printing. in Advances in Printing and Media Technology, 36th International Research Conference. 2009. Stockholm, Sweden.
7. Costa, T.G., et al., The influence of paper surface sizing on inkjet pigment penetration. Appita Journal, 2010. 63(5): p. 392-398.
8. Saraiva, M.S., et al., A New Approach for the Modification of Paper Surface Properties Using Polyoxometalates. Materials, 2010. 3: p. 201-215.
9. Sousa, S., et al., Long-chain quaternary EPK2 surface sizing and print quality evaluation. Appita Journal, 2010. 63(4): p. 300-307.
10. Lundberg, A., et al., Microscale droplet absorption into paper for inkjet printing. Nordic Pulp and Paper Research Journal, 2011. 26(1): p. 142-150.
11. Fardim, P., Paper and Surface Chemistry - Part 2 - Coating and Printability. TAPPI Journal, 2002. 1(9): p. 44-56.
12. Xu, R., P.D. Fleming, and A. Pekarovicova, The Effect of Ink Jet Paper Roughness on Print Gloss. Journal of Imaging Science and Technology, 2005. 49(6): p. 660-665.
13. Kowalczyk, G.E. and R.M. Trksak, Image analysis of ink-jet quality for multi use office paper. TAPPI Journal, 1998. 81(10): p. 181-190.
14. Fleming, P.D., et al., Interpretation of Dot Fidelity of Ink Jet Dots Based on Image Analysis. Journal of Imaging Science and Technology, 2003. 47(5): p. 394-399.
15. Tse, M.-K., PIAS-IITM - A High-Performance Portable Tool for Print Quality Analysis Anytime, Anywhere. 2007, Journal of the Imaging Society of Japan: Kyoto. p. 1-4.
16. Yang, L., et al., A novel method for studying ink penetration of a print. Nordic Pulp and Paper Research Journal, 2005. 20(4): p. 423-429.
17. Yang, L., et al., Studying ink penetration with microscopic and spectroscopic techniques. Journal of Imaging Science and Technology, 2006. 50(4): p. 327-332.
Agradecimentos
Os autores agradecem o financiamento do projecto PADIS (FCOMP-01-0202_FEDER-005348), projecto este que foi co-financiado pela União Europeia através do FEDER (Fundo Europeu de Desenvolvimento Regional) no âmbito do QREN (Quadro de Referência Estratégico Nacional 2007-2013) através do COMPETE (Programa Operacional Factores de Competitividade).
Os autores agradecem igualmente todo o apoio concedido pela Unidade de Materiais Têxteis e Papeleiros, pela Unidade de Detecção Remota, pelo Centro de Óptica, pelo Departamento de Química e pelo Departamento de Física da Universidade da Beira Interior.
Os autores também desejam apresentar os seus agradecimentos ao RAIZ Instituto de Investigação da Floresta e Papel pelos conjuntos de amostras de tintas e papéis que foram facultados para análise com ambos os sistemas ópticos implementados, e finalmente ao Laboratório de Anatomia Patológica da Faculdade de Ciências da Saúde da Universidade da Beira Interior pela preparação das amostras em parafina.
21
Steady and Unsteady Bifurcation Flows of Non-Newtonian Inelastic Fluids H. M. Matos 1, P. J. Oliveira 1
1Departamento de Engenharia Electromecânica, Unidade de Materiais Têxteis e Papeleiros, Universidade da Beira Interior, Rua Marques D’Ávila e Bolama, 6200-001 Covilhã, Portugal
Abstract Steady and unsteady laminar flows in a planar 2D T-junction are studied numerically for non Newtonian inelastic fluids whose rheological characteristics are similar to those of blood. These computational fluid dynamics simulations scan variations of inertia, flow rate ratio and shear thinning, with the objective of determining the sizes of the recirculating eddies formed near the bifurcation and the resulting distribution of the shear stress fields. In hemodynamics such flow complexities are related to the genesis and development of vascular diseases, like the formation of atherosclerotic plaques and thrombi. To represent the decay of viscosity with shear rate we apply the Carreau-Yasuda equation. In many comparisons of the present parametric study it was require that the level of inertia is approximately the same when the power law index was variable, which implies a consistent definition of the Reynolds number. Introduction Bifurcation flows are important in many engineering and bio-engineering applications. In engineering applications, bifurcations are commonly used in liquid distribution systems. However when the working fluid is composed by a mixture of a number of fluids and other materials like it may be found in dyeing processes in the textile industry or in the production process of paper, phase distribution in the main and the branch ducts is inevitably different, affecting the flow control and processing facilities downstream. In some situations, like in the petroleum industries, this phenomenon is advantageous and is used to accomplish the first stage of oil and gas phase separation, with attending improvement in the efficiency of the transport system [1]. Bio engineering applications are well illustrated by the hemodynamical circulatory system, in which blood flows along successive levels of arterial bifurcations producing highly complex flow patterns that promote the appearance of regions with flow separation and recirculation, which are well correlated with to the emergence and development of vascular diseases [2, 3]. Due to the highly complex flow, the endothelium wall is more easily damaged and this facilitates the macromolecules to migrate into the arterial wall, leading finally to the atherosclerotic plaque formation [4]. The interaction between blood flow and the artery wall, through the action of the fluid shear stress, is known to be extremely relevant. Blood is a complex fluid that consists in a suspension of platelets, leucocytes and erythrocytes in plasma [5], and possesses therefore non-Newtonian properties. Blood exhibits a shear-thinning viscosity, is thixotropic and
viscoelastic [6]. Among the various non-Newtonian blood properties we concern our attention in shear thinning effects. These computational fluid dynamics simulations scan variation of inertia, flow rate ratio and shear thinning, on steady and unsteady laminar flows in a planar 2D T-junction. Inertia effects were varied through the Reynolds number (
1Re u H ), from 50 to 1000. The shear-
thinning viscosity follows the Carreau-Yasuda model in which the power law exponent was changed according to the intensity of viscosity variation. Finally the flow rate ratio (
3 1Q Q ) varied from 0.1 to 0.9.
Numerical Simulation
Differential Equations
For the simulation of incompressible and isothermal, laminar, time-dependent flows, the equations to be solved are those expressing conservation of mass (Eq. 1) and linear momentum (Eq. 2):
0u (1)
pt
uuu (2)
Where u is the velocity, p is the pressure and is the
fluid density. The stress tensor in Eq. (2) is specified by a rheological constitutive model which depends on whether the fluid is Newtonian or non-Newtonian (inelastic). For Newtonian fluids the stress tensor follows the Newton law for viscosity expressing a linear and explicit stress-strain rate relationship ( 2 D ) where D is the rate-
of-strain tensor, represents the fluid viscosity and is
the shear rate tensor. For non-Newtonian inelastic fluids (Generalized Newtonian Fluids) the Carreau–Yasuda model [7] (Eq. 3) is followed to represent the viscosity variation with shear rate.
1
0 1n aa (3)
In Eq. (3) 0 and are the zero and infinite shear rate
viscosities, is a constant time and n is the power law exponent. The magnitude of these parameters is obtained from [8].
Numerical Method
We apply the finite-volume method on non-staggered meshes in which all variables are stored at the centre of cells forming the mesh [9]. The coupling between the velocity and stress fields employs the method of Oliveira et al. [10] later modified by Matos, et al. [11]. Spatial discretisation of the convective terms is accomplished with the high resolution scheme CUBISTA [12] and
22
temporal discretisation of the unsteady term follows the three time level scheme [13]. The pressure-correction method employed is based on the SIMPLEC algorithm.
Geometry and Computational Mesh
The simulations were carried out in a 2D T-shaped geometry (Fig. 1) having a constant cross section area with height H . The flow conditions were similar to those of Miranda et al. [6]. At the inlet a Dirichlet boundary conditions were used, by imposing a parabolic velocity profile for the steady state flows, while for transient flows the velocity profile is pulsating and generated by a sinusoidal pressure gradient:
0 cos( )S
dpK K t
dx (6)
Here SK is the magnitude of the steady pressure
gradient and 0K is the magnitude of the oscillating
pressure gradient (0 2.585SK K ). The Womersley
number is 1 2( ( ) ) 4.864H .
At the outlets, Neumann boundary conditions were imposed. The other boundary planes are solid walls where the no slip boundary condition was imposed. The mesh is formed by 12800 control and the study of mesh refinement can be found in Matos et al. [11]. For unsteady flows the time step is 35 10 .
x
y
H
XS
Q1 Q2
Q3
Ytot = 21 H
Xtot = 26 H
H
XL XR
YL
YR
YS
H
Figure 1 – Schematic representation of the simulation geometry.
Definition of effective Reynolds number
For Newtonian fluids the viscosity does not change and the Reynolds number is varied through the fluid velocity at the inlet. On the other hand for non Newtonian fluids, viscosity depends on the shear rate (Eq. 7) which affects the Reynolds number calculation and produces a hidden variation of the Reynolds number in these cases when Newtonian conditions are used.
1 1 with / 2
u H uRe
H (7)
In order to maintain the effective Reynolds number constant for all cases it is necessary to adopt a modification in the calculation of Re . For this purpose in
this work we adopted an iterative procedure to determine the mean velocity that the flow must have at inlet, for an specified Reynolds number, when the corresponding viscosity of the fluid is based on the Carreau-Yasuda model, for different power law exponents, through the expression:
1
1 0 11 2
na aRe
u u HH
(8)
During this text we adopt by default the consistent Reynolds number obtained through the iterative process defined by Eq. (8). In some results the number of Reynolds was obtained by the two methods: we refer to the “Newtonian Reynolds method” or ReNewt
when the
Newtonian viscosity is used, and to “Modified Reynolds method” or ReMod
, when the viscosity is obtained from
the Carreau-Yasuda model and defined in a consistent way.
Results and Discussion The results presented are normalised, using as length scale the channels height H , as velocity scale the average velocity of the inlet flow (
1u ), as stress scale the value of
the wall shear stress at inlet under fully-developed steady flow (
1 16 /w u H ), and the ratio 2 / for time scale.
In the stress scale the characteristic viscosity depends on fluid; for Newtonian and GNF fluids with the Newtonian Reynolds method, the Newtonian viscosity is used , while for GNF fluids with the Modified Reynolds method the viscosity is obtained from the Carreau-Yasuda model at
1 1 0.5u H .
The principal dependent variables in these study are the recirculation lengths of both eddied created in the main and branch arms (Fig. 1), and the shear stress fields.
Steady flow
Figures 2 and 3 show simultaneously the variation with inertia and flow rate ratio of the horizontal and vertical recirculation lengths. For the horizontal recirculation length we compare the solution obtained with the Newtonian fluid and the non Newtonian fluids (GNF) using both the “Newtonian Reynolds method” and the “Modified Reynolds method”. For the vertical recirculation length only the Modified Reynolds method is presented. Both recirculation lengths
LX
and LY
increase
monotonically with Reynolds number. The eddy in the horizontal branch increases linearly with Reynolds number for flow rate ratios lower than 0.8. The increase in the vertical eddy length is not linear for all extraction ratios due to the interaction of the main vertical recirculation with a new recirculation formed immediately downstream, in the opposite side wall of the secondary branch, which acts as to squeeze the first and delay its growth.
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Figure 2 – Horizontal recirculation length as a function of
inertia (Re) and extraction ratio ( ) for Newtonian and GNF
fluids.
Figures 2 and 3 also show an increase in length with extraction ratio up to a maximum for 0.6 , while for
higher values of extraction, the size of the eddies decrease. The GNF fluids induce somewhat longer recirculation lengths for both recirculations with the Newtonian Reynolds method define Re such differences in recirculation lengths are artificially accenjtuated, especially for high Reynolds numbers, when the Newtonian and non Newtonian viscosity magnitudes become very different. With the consistent definition of Reynolds number of the modified method the results for Newtonian and GNF fluids are very similar, thus demonstrating that the non-Newtonian shear thinning
effect could be accounted for by the inertial effect when the Reynolds number is obtained in a consistent way.
Figure 3 – Vertical recirculation length as a function of inertia
(Re) and extraction ratio ( ) for the GNF ( ReMod) case.
Figure 4 –Shear stress fields for increasing Reynolds numbers,
at 0.7 ; GNF ( ReMod) case.
Figure 4 presents the evolution of shear stress with inertia for two Reynolds numbers ( Re 100 and Re 300 ). The shear stress magnitude increases with inertia, but there always exist areas of very low shear stress close to the wall in the recirculation zones, while high stresses are generated in the recirculation boundaries, located in the main and the side branches. Such distribution induces high stress gradients and the possibility of shear stress oscillations, in space and time, which may facilitate the inflammatory process and the triggering of an atherosclerotic plaque. In general a comparison of the
XX X X X X X X X X X X X X X X X X X X
Re0 200 400 600 800 1000
0
6
12
18
24=0.1=0.2=0.3=0.4=0.5=0.6=0.7=0.8=0.9
XXL
Newtonian
XX
XX
XX
XX
X X X X
Re0 200 400 600 800 1000
0
6
12
18
24
XL
GNF(Re Newt)
XX X X X X X X X X X X X X X X X X X X
Re0 200 400 600 800 1000
0
6
12
18
24
XL
GNF(Re Mod)
XX
XX
XX X X X X X X X X X X X X X X
Re0 200 400 600 800 1000
0
6
12
18
24
YL
GNF(Re Mod)
1
0.30
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
7 1.056 1.025 14 0.33 02 -0.0061 -0.012
Y
Re=100
0.3 0
1
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
7 1.056 1.025 14 0.33 02 -0.0061 -0.012
Y
Re=300
24
stress fields between the Newtonian and the GNF fluids shows only minor differences with the Newtonian case presenting higher shear stress fields (in modulus) when compared with GNF fluids. Figure 5 shows the evolution of the shear stress field with flow rate ratio. The flow rate ratio promotes a slight increase of maximum shear stress magnitudes (in modulus). It is noted that for low extraction ratios the higher shear stresses are registered along the main duct in the wall layer, while for high extraction ratios they are registered along the secondary branch. The maximum magnitudes occur where layers of fluid having high and low velocities come into contact, which results in increased local shearing of the flow.
Figure 5 –Shear stress fields for increasing extraction ratio, at
Re 100 ; GNF ( ReMod) case.
The influence of shear thinning variation on the two eddy lengths is presented in figure 6 using the Modified
Reynolds method. When the Reynolds number is defined in a consistently way the shear thinning variation promote only slight differences, noting, however, smaller lengths for the Newtonian case ( 1n ).
Figure 6 – Variation of
LX and LY with shear thinning and Re
for GNF fluids with Newtonian Reynolds method and 0.7 .
The influence of shear thinning variation does not promote the existence of large variations in the shear stress field. The shear stress variation is not monotonous, initially the increase in the power law index results in a decrease in modulus of the shear stress magnitudes to minimum values that occur for ( 0.6n ). After that they increase to the maximum shear stress magnitudes that occur for the Newtonian case ( 1n ), as shown by the maximum and minimum values registered in table 1, for different power law index.
Table 1 – Maximum and minimum shear stress for various power law indices.
Power law
index n=0.2 n=0.4 n=0.6 n=0.8 n=1
1MaxXY w 1.22 1.15 1.11 1.18 1.35
1MinXY w -7.25 -6.44 -5.76 -6.20 -8.40
Unsteady flow
All the results presented in this section were obtained at constant inertia, with Re 102 . For unsteady periodic flows the recirculation lengths and shear stresses also change during the cycle. In figure 6 we
0.8
1
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
6 1.025 14 0.83 02 -0.0021 -0.006
Y
=0.2
0.4
1
0
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
6 1.025 14 0.43 02 -0.0021 -0.006
Y
=0.6
0.2
1
0
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
6 1.025 14 0.23 02 -0.0021 -0.006
Y
=0.8
X
XX
XX
XX
XX
XX
XX
XX
XX
XX
X
E
EE
EE
EE
EE
EE
EE
EE
EE
EE
E
Re0 200 400 600 800 1000
0
3
6
9
12
n=0.1n=0.2n=0.3n=0.4n=0.5n=0.6n=0.7n=0.8n=0.9n=1.0
X
E
XL
=0.7
GNF(Re Mod)
X
X
XX
XX
XX
X X X X X X X X X X X X
E
EE
EE
EE
EE E E E E E E E E E E E
Re0 200 400 600 800 1000
0
3
6
9
12
YL
=0.7
GNF(Re Mod)
25
present the variation during the cycle of the separation and reattachment points of both recirculations using the GNF fluid ( ReMod
).
This figure shows that the horizontal recirculation is not present during the whole cycle, while the vertical recirculation is always present. However, in the latter case an abrupt reduction in length occurs after the middle of the cycle, which is associated with the breakup of the recirculation into two vortices due to the emergence of a new bubble near the wall. This phenomenon is seen by contrasting the red line (square symbols), which corresponds to the first reattachment point (unique before the division), and the purple line (circular symbols) which corresponds to the second separation point associated with a second recirculation that tends to disappear later in the cycle.
Figure 6 –Variation of the separation and reattachment points
( 0.7 ; 0.3568n ).
The following figures show the influence of shear thinning and extraction ratio upon the recirculation lengths. Figure 7 show the influence of shear thinning variation at constant flow rate ratio ( 0.7 ) and figure 8
shows the influence of flow rate ratio at constant shear thinning intensity ( 0.3568n ). Just as occurred in the case of steady flows (Figure 6) the increase of shear-thinning (decrease of n ) does not afect significantly the results, resulting in slight increase of both
LX and LY recirculation lengths. For the horizontal
recirculation, shear thinning also results in shorter residence times over the cycle, while the vertical recirculation tends to split earlier. The flow rate ratio affects significantly the magnitude of the eddy lengths. The horizontal recirculation length reaches its maximum magnitude near the middle of the cycle and in this part of the cycle it presents a behaviour similar to what was registered for steady state flows. It tends to increase initially with the flow rate ratio, to a maximum that occurs at 0.6 , followed by a decrease
for higher flow rate ratios.
Figure 7 – Variation of recirculation lengths with n .
Figure 8 – Variation of recirculation lengths with extraction
ratio.
t0 0.2 0.4 0.6 0.8 1-1
0
1
2
3
4
5XSXRYS1YR1YS2YR2
XSXRYSYR
=0.7n=0.3568
t0 0.2 0.4 0.6 0.8 1
0
1
2
3
n=0.1n=0.2n=0.3n=0.4n=0.5n=0.6n=0.7n=0.8n=0.9n=1.0
XL
=0.7
t0 0.2 0.4 0.6 0.8 1
0
1
2
3
n=0.1n=0.2n=0.3n=0.4n=0.5n=0.6n=0.7n=0.8n=0.9n=1.0
YL
=0.7
XX X X
X
XX
XX
X X X X X X X X XX
XX
X X XX
t0 0.2 0.4 0.6 0.8 1
0
2
4
6=0.1=0.2=0.3=0.4=0.5=0.6=0.7=0.8=0.9
X
XL
n=0.3568
X X X X X X X X X X X X X X X X X X X X
XX X X X
t0 0.2 0.4 0.6 0.8 1
0
2
4
6=0.1=0.2=0.3=0.4=0.5=0.6=0.7=0.8=0.9
X
YL
n=0.3568
26
For the specific shear thinning intensity here used ( 0.3568n ) there is no recirculation in the main branch for very low flow rate ratios. Increasing the flow rate ratio promotes the appearance of the horizontal recirculation, whose residence time increases monotonically whith extraction ratio. The vertical recirculation length is seen to increase with flow rate ratio, however the rate of increase is reduced as flow rate ratio increases. Furthermore the increase of flow rate ratio also tends to anticipate the division of the vertical recirculation and, for very low flow rate ratios, such division does not occur. The variation of the shear stress field with extraction ratio presents a similar behaviour to what was observed in the case of steady flows: there is a slight increase of the maximum shear stress magnitudes (in modulus) with extraction rate. The location of the maximum shear stresses in modulus tends to occur in the branch where fluid attains larger velocities over the stagnated standing eddy. For unsteady flows shear thinning does not promote significant variations in the shear stress fields like it was observed for steady flows. However in this case the variation is monotonous, with an increase in the the shear stress field as the power law index is raised, as seen by the maximum and minimum values registered in table 2, for different power law index.
Table 2 – Maximum and minimum shear stress for various power law indices.
Power law
index n=0.2 n=0.4 n=0.6 n=0.8 n=1
1MaxXY w 3.99 4.39 5.14 6.60 9.50
1MinXY w -2.61 -2.87 -3.67 -4.12 -5.50
Conclusions Numerical simulations were conducted for flow in a two-dimensional bifurcation with Newtonian and non-Newtonian inelastic fluids. For non-Newtonian flows it was necessary to define the Reynolds number in a consistent way in order to maintain the same inertia as in corresponding Newtonian cases. This was done by including the shear thinning effects on the viscosity used in the Reynolds number calculation. The comparison between Newtonian and non Newtonian fluids show that GNF fluids tend to present longer recirculation lengths in the main and the side branches and reduced shear stress field magnitudes. In steady flows the influence of shear thinning does not result in a monotonous behaviour in the recirculation lengths and shear stress fields variation, while for unsteady flows the behaviour is almost monotonous. An increase of the power law exponent results in a decrease of both recirculation lengths and an increase of the shear stress magnitudes. Flow rate ratio, for both steady and unsteady flows, does not show a monotonous behaviour. In steady state flows,
the recirculation lengths increase with flow rate ratio up to a maximum values at 0.6 , and decrease after that. For
unsteady flows this behaviour is much less pronounced and it is only registered for the horizontal recirculation in the middle of the cycle. In the case of the vertical recirculation, the maximum value is obtained for 0.7
during part of the cycle. For both fluids the maximum magnitudes of shear stresses present a slightly increase with flow rate ratio and the location changes with flow rate ratio variation; high shear stress magnitudes occur in the branch in the shear layer outside the recirculation eddy. References 1. Margaris, P.D., Chem. Eng. Proc., 46(2), 150, 2007. 2. Ku, D., Annu. Rev. Fluid Mech., 29, 399, 1997. 3. Berger, S.A. and Jou, L-D., Annu. Rev. Fluid Mech.,
32, 347, 2000. 4. Crowther, M.A., Hematology, (1), 436, 2005. 5. Anand, M. and Rajagopal, K. R., Int. J. Cardiovasc.
Med. Sci., 4(2), 59, 2004. 6. Miranda A.I.P., Oliveira P.J. and Pinho F.T., Int. J.
Numer. Meth. Fluids, 57(3), 295, 2008. 7. Carreau, P.J. Trans. Soe. Rheol., 16(1), 99, 1972. 8. Banerjee, R.K., Cho, Y.I. and Kensey, K.R., Int. J.
CFD, 9(1), 23, 1997. 9. Oliveira, P.J., Ph.D. Thesis, University of London,
1992. 10. Oliveira, P.J. and Pinho, F.T., Numer. Heat Transfer
B, 35(2), 295, 1999. 11. Matos, H.M.M., Alves, M.A. and Oliveira P.J.,
Numer. Heat Transfer B, 56(5), 351, 2009. 12. Alves, M.A., Oliveira, P.J. and Pinho, F.T., Int. J.
Numer. Meth. Fluids, 41(1), 47, 2003. 13. Oliveira, P.J., J. Non-Newt. Fluid Mech., 101 (1-3),
113, 2001. Acknowledgements H.M. Matos wishes to acknowledge the financial support provided by FCT trough the grant SFRH/BD/18062/2004.
27
Ultrafiltration and biodegradability of cork processing wastewaters: influence of pH
A. Gomes1, L. Silva1, R. Simões1, N. Canto1 and A. Albuquerque2
1Department of Chemistry & UMTP, University of Beira Interior, 2Department of Civil Engineering and Architecture, University of Beira Interior
Abstract
The biodegradability of cork processing wastewater was accessed by the ratio between the Biological Oxygen Demand (for 5 and 20 days of incubation, BOD(5) and BOD(20), respectively) and the Chemical Oxygen Demand (COD). The raw effluent presented a BOD(5)/COD of 0.27 and a BOD(20)/COD of 0.37. In order to concentrate the biorecalcitrant pollutants for the ozonation stage, which intends to increase the biodegradability, the wastewater was submitted to Ultrafiltration (UF) with a membrane having a molecular weight cut-off (MWCO) of 10 kDa. The influence of pH on the membrane performance and concentrates oxidation was studied at effluent natural pH and set close to 3 and 10. The productivity and selectivity of the membrane were favored at alkaline pH. For batch operation at a pressure of 3 bar the COD removal was 49.8%, 75.8% and 82.2% for 3.22, 6.87 and 10.09 pH values respectively. The ratio between the ozone applied (O3(appl.)) and initial COD (CODi) ranged from 0.16 to 1.41 for trials with concentrates produced for a Concentration Factor (Fc) of 2.00. However, permeates presented a COD ranged from 733 to 1117 mg/L which is not compatible with water reuse. The increase in BOD(5)/COD was up to 0.34 and the BOD(20)/COD ranged from 0.29 to 0.42. During the oxidation the removal of COD was favored at alkaline pH but the biodegradability increase was higher for acid and natural pH conditions were the molecular ozone prevails.
Introduction The production of stoppers used to seal wine bottles are the most valuable outcome of the cork industry, which accounts for approximately 15% of the weight of total cork production and two-thirds of cork revenues [1]. Therefore, the economical sustainability of the cork production is closely dependent on public preference for stoppers made of cork in detriment of synthetic materials. The competition with synthetic materials can be overcome if cork production and transformation are apprehended as environmental sustainable activities. However, the first stage of the cork industrial process is focused on the cleaning, disinfection and moistening of the raw material. For this purpose, the corkwood is immersed in boiling water up to one hour after being dried in open air from three to six months [2,3]. Depending on the quality of raw material and type of product this hot processing water can be reuse from 6 up to 30 times. The amount of water used
varies from company to company and was being reported between 0.35 and 0.70 m3/t [3,4]. The resulting effluent presents a dark color and contains some corkwood extracts such as phenolic acids (gallic, protocatechuic, vanillic, syringic, ferulic, ellagic, among many others) and tannic compounds [2]. This stage is of critical importance for the removal of chemical contaminants, which are being related with wine off-flavors during the storing process, namely the 2,4,6-trichloroanisol [1]. The depuration of cork boiling wastewater is difficult due to the concentration of bio-recalcitrant compounds (phenols and tannins), high Chemical Oxygen Demand (COD), ranging from 4.5 to 5.5 g/L, Biological Oxygen Demand after 5 days incubation (BOD5) between 1.1 and 1.8 g/L [2, 3], which correspond to a BOD5/COD ratio bellow the recommended limit of 0.40 for the implementation of depuration processes based on biological activity [5]. Beside the difficulties to save water during the boiling process, to implement the depuration process allowing companies to fulfill the limits for discharge or reuse of the
the processing industry. Therefore, we may conclude that the reduction of water consumption and of the pollution emission are of critical importance for the future of the cork sector, namely in Portugal, which is the leading country for the production and transformation of cork [2]. Membranes processes have been proven to be extremely efficient when applied to industrial wastewaters, not only because they selectively concentrate pollutants, in some cases allowing their reuse, and most frequently the characteristics of permeate are compatible with reuse or recycling. The performance of ultrafiltration (UF) membranes is greatly influenced by the concentration polarization which can lead to gel layer and ultimately resulting in membrane fouling [6]. The interactions solute-solute and membrane-solute have a great influence on membrane performance (selectivity and permeate flux). For instance, it was reported the possibility of microfilters remove salts and in the case of UF and nanofiltration (NF) rejecting solutes with molecular weight (MW) bellow the Molecular Weight Cut-Off (MWCO) [6,7]. Therefore, the variation of solution pH, which can be easily accomplished and monitored, can lead to alterations of UF membranes performance and deserves to be studied with cork processing wastewaters.
28
The membrane selectivity is usually expressed through the rejection coefficient (R) calculated according to:
(eq. 1)
where Ca is the concentration for the feed solution and Cp the permeate concentration. For batch operation is common to report the rate of concentration achieved by calculating the concentration factor (FC):
(eq. 2)
where Vi corresponds to the initial volume solution and Vp to the permeate volume accumulated. During batch operation membrane performance is reduced as the FC increases; because rejected solutes are continually being accumulated in the concentrate solution. The depuration processes based on biological treatment options have proved themselves to be the best technical and economical option even with effluents from textile, paper, pharmaceutical and chemical industries [5]. However, the efficiency of biological treatments is significantly dependent on the biodegradability of the pollutants in the wastewater. Up to date most of the published studies dealing with cork processing wastewaters and biological processes resulted in insufficient COD removal. For instance, with activated sludge process the reduction varied from 13 to 37% [3]. As a result, the most frequent treatment sequence starts with a pre-treatment by coagulation-floculation or primary sedimentation followed by biological treatment after mixture with domestic wastewaters. However, the concentration of phenols and tannins in the wastewater ranged from 0.3 to 0.7 g/L and 0.2 to 0.5 g/L, respectively, due to their bio-recalcitrant nature are not readily removed by conventional municipal wastewater treatment and are released to the receiving watercourses [3,4]. The chemical oxidation techniques have being increasingly used to reduce the organic pollution load of effluents in order to obtain water with the quality required for reuse or discharge, and applied to raw wastewaters or membranes concentrates to increase their biodegradability [4]. One widely used procedure is ozonation (Ozone, O3), namely with wastewaters containing hazardous organic and inorganic compounds. Its powerful oxidizing capabilities and the absence of hazardous decomposition products make ozone a potentially useful pre-treatment agent for converting bio-refractory compounds in others with low MW and with increased biodegradability potential [4,8]. As for the UF, the solution pH can change the reactivity of ozone in heterogeneous systems, for acid conditions (pH close to 3.0) the oxidation process involves mostly molecular ozone (O3), which is a less reactive but more selective oxidant than the hydroxyl
radicals (OH ) that result from ozone degradation at alkaline pH [9]. In this study we used a UF membrane (with a MWCO of 10 kDa) and cork processing wastewaters at three different pH values: natural and set close to 3.0 and 10.0, to access the influence of pH on membrane performance and on the increase of concentrates aerobic biodegradability through ozonation.
Materials and Methods
Cork boiling wastewater We used an effluent collected in an industry located in the Portalegre district. The sample characterization is resumed in Table 1 for pH, COD, BOD5, BOD20, Total Organic Carbon (TOC), total phenols (TF) concentration, tannin content and absorbance at 254 and 580 nm used for aromatic compounds and colour measurement. All the analytical determinations were performed according standard methods [10], except for phenol and tannins which were quantified according the methodology proposed by Makkar et al. (1993) [11]. Table 1: Characteristics of the raw wastewater.
Parameter (units)
Raw Wastewater (RW)
pH ( - ) 5.81 COD (mg/L) 1865 BOD5 (mg/L) 498 BOD20 (mg/L) 684 TOC (mg/L) 723 Absorbance (254 nm)(1) 0.562 Absorbance (580 nm)(2) 0.554 TF (mg tannic acid/L) 523 Tannins (mg tannic acid /L) 399
(1) diluition of 1:50; (2) diluition of 1:2 ; Filtration experimental set-up The UF assays were performed in a pilot filtration unit M20 from DSS (Naskskov, Denmark) with 0.144 m2 of the UF membrane GR81PP (with a MWCO of 10 kDa) in a plate-and-frame configuration. The effluent samples were pre-filtered using cartridge filters with a nominal pore size of 10 and 5 µm. The influence of pH on membrane performance was studied in recirculation (constant concentration) and concentration mode (batch operation) with 10 to 25 L of effluent at natural pH (Table 1) and with the pH set close to 3 and 10 using H2SO4 and NaOH aqueous solutions (10%), respectively. Ozone experimental set-up A Fischer Model 502 (Bonn, Germany) ozone generator was employed to produce ozone gas from dry, pure oxygen. The ozone concentration in the gas phase was close to 50 mg/L (for a flow rate of 50 L/h). The ozonation of concentrates was carried out in a close vessel
29
of 1L provide with a mechanical stirrer to promote the transfer of ozone gas in to the solution. The ozonation trials lasted for 10, 20, 40, 60 and 80 minutes, which corresponds to an amount of ozone applied between 400 and 3200 mg. Aerobic biodegradability The BOD5 and BOD20 determinations were performed in an OxiTopR OC100 system (WTW, Germany) according the respirometric method [10] using a procedure described elsewhere [12].
Results and Discussion
The characteristics of the raw wastewater (RW) are resumed in Table 1 and they are whiting those reported by other authors. The main feature is the low biodegradability, with a BOD(5)/COD ratio of 0.27 and a BOD(20)/COD ratio of 0.37 and consequently the technical viability for the implementation of biological treatment options is clearly limited. It deserves to be notice that BOD of the RW after 5-constant value because the biological oxidation of the organic compounds proceeds very slowly. Therefore, despite the fact that BOD(5) being the parameter usually considered in regulations and the ratio BOD(5)/COD frequently used as biodegradability indices, we increased the incubation time up to 20-days, which proved to be enough to have a constant value for the BOD with RW, permeates and concentrates before and after oxidation. The BOD(5)/BOD(20) ratio for the RW was 0.73 and is closed to 0.75 previously reported by Bernardo et al. (2011) [4]. According the EU directive 91/271/CEE the pollution load in the RW is more than 12 time over the legal discharge limit of 40 and 150 mg/L for BOD(5) and COD, respectively. Therefore, high pollutants removals are required to accomplish the emission limits or for treated water reuse. The influence of pH on UF membrane performance was first studied running recirculation assays (constant concentration) at constant temperature (25ºC), with transmembrane pressures ranging from 1 to 6 bar and 0.87 m/s of cross-flow velocity (the maximum value reached by the recirculation pump, used to minimize concentration polarization). In Fig. 1 we compared the permeation flux with RW at various pH and in Fig. 2 we represented the COD removal. These results clearly point out that alkaline pH is the most favorable for the membrane performance. At natural pH the values of R varied between 69.5 and 81.9% and the COD permeates ranged from 376 and 635 mg/L. Close values were previously reported by Bernardo et al. (2011) [4] for a UF membrane having a MWCO of 13.6 kDa, the COD removal for a transmembrane pressure of 3 bar varied from 69.5 to 81.9% with a RW having a pH of 5.14. In our study the color removal was almost complete for the range of conditions used. The R values for the absorbance at 580 nm, which was used to measure color, varied from
87.9 and 98.4 allowing the permeates to be close to transparency. For pressures over 3 bar the net income in permeate flux resulted from pressure increase is clearly reduced, namely for RW at acid pH (Fig. 1). Therefore, the concentration assays were performed at constant pressure (3 bar).
Fig. 1: Variation of permeate flux with pressure and pH (constant concentration).
Fig. 2: Variation of R for COD with pressure and pH (constant concentration). The concentration assays were also performed at constant temperature (25ºC) and pressure (3 bar), and the amount of permeate collected was enough to achieve a FC of 2.00 with RW samples at natural, acid and alkaline pH. Is important to report that due to significant differences on the permeate flux this experiments lasted different time accordingly the RW pH (Fig. 3). As expected the permeate flux and R decreased with FC increased. This means that as the permeate volume increases their quality is reduced by the decay in membrane selectivity due to increase of pollutants concentration in the recirculation solution. We limited the FC because the characteristics of permeates (for all the pH values tested) presented already COD values over 150
0
10
20
30
40
50
60
0 2 4 6
Per
mea
te f
lux
((l/m
2 .h)
Pressure (bar)
pH (=3.22; acid)
pH (=5.81; natural)
pH (=10.09; alkaline
0
25
50
75
100
0 2 4 6
R (
CO
D)
(%)
Pressure (bar)
pH (=3.22; acid)
pH (=5.81; natural)
pH (=10.09; alkaline
30
mg/L, which is the legal limit. Therefore, permeates need also to be treated before being reused or discharged into natural watercourses. The higher permeate flux were also attended at alkaline pH. The reduction on flux with FC was 22%, 29% and 38% at alkaline, natural and acid pH, respectively (Fig. 3).
Fig. 3: Variation of the permeate flux with the FC and RW pH at transmembrane pressure of 3 bar. The results for the study of the pH influence on membrane performance and ozonation are resumed in Table 2. Table 2 Results from oxidation of concentrates and permeates at natural pH, acid and alkaline for Fc=2.00.
Sample (pH)
Oxidation Time (min)
pH COD
(mg/L) BOD5/COD
BOD20/COD
Conc. Acid pH
(pH=3.22)
( - ) 3.19 2612 0.22 0.31 10 2.47 2304 0.27 0.33 40 2.23 1923 0.31 0.37 80 2.04 1577 0.34 0.41
Permeate ( - ) 3.27 1117 0.42 0.54
Conc. Natural pH (pH=5.81)
( - ) 5.04 2967 0.20 0.31 10 4.52 2588 0.25 0.34 40 4.07 2210 0.28 0.40 80 3.11 1807 0.33 0.42
Permeate ( - ) 5.41 802 0.41 0.53
Conc. Alkaline pH (pH=10.09)
( - ) 8.99 3088 0.18 0.27 10 7.42 2646 0.20 0.29 40 5.17 2169 0.22 0.30 80 4.32 1758 0.25 0.33
Permeate ( - ) 9.32 733 0.42 0.56 The selectivity and permeate flux of the GR81PP membrane in the concentration assays were favored by the alkaline pH. The COD removal was 46%, 51% and 58% for acid, natural and alkaline pH, respectively (Table 2). However, the COD values for permeates are clearly above the limit for discharge and necessary for potential reuse, but the organic fraction in the permeates presents biodegradability index that are clearly above those from
concentrates, which means that pollutants with MW over 10 kDa are more recalcitrant than those with small MW. Therefore, permeates depuration can be achieved by biological processes because the BOD(5)/COD and BOD(20)/COD are over 0.40 which was not the case with RW. The reductions of COD achieved by oxidation were from 11.8-39.6%, 12.8-39.0% and 14.3-43.1% for acid, natural and alkaline pH, respectively. The O3(appl.)/CODi ratio ranged from 0.19 to 1.53 and were not enough to overcame the limit of 0.40 for all the concentrates produced. Beside the reduction on ozone yield with oxidation time (data not show) further work need to be done to accomplish the limits for biodegradability enhancement that can be achieved by ozonation, which requires the increase of the amount of ozone applied. For all cases the ozonation resulted in pH drop because the organic matter oxidation leads to the formation of acidic organic compounds of lower molecular weight than the original compounds.
Conclusions
For the integrated process, UF and concentrates ozonation, the alkaline pH proved to be the best compromiss between membrane performance and biodegradability enhancement. However, the ratio O3(appl.)/CODi need to increase to maximize the biodegradability enhancement. The possibility of permeates reuse will require the use of more selective membranes, namely, nanofiltration.
References 1. Mazzoleni, V., Dallagiovanna, L., Trevisan, M.,
Nicelli, M., Chemosphere 58, 1547, 2004. 2. Greeves, A.J., Churchey, J.H., Hutching, M.G.,
Philips, D.A.S., and Taylor, J.A., Water Res., 35, 1225, 2001.
3. Benítez, F.J., Acero, J.L., and Leal, A.I., Sep. and Purif. Technol., 50, 354, 2006.
4. Machado, M.D., Madeira, L.M., Nogales, B., Nunes, O.C., and Manaia, C.M., Chemosphere, 64, 455, 2006.
5. Bernardo, M., Santos, A., Cantinho, P., and Minhalma, M., Water Res., 45, 904, 2011.
6. , Butterwort Heinemann Ed., USA, 2nd Ed.
2001. 7. Schafer, A.I., Fane, A.G., and Waite, T.D.,
2005. 8. Porter, J.J., and Gomes, A.C., Desalination, 128, 81,
2000. 9. Davies, R.A., Rinker, R.G., and Sandall, O.C., J. of
Hazard. Materials, 178, 65, 1995. 10.
Examination of St Edition, 2005.
0
5
10
15
20
25
1,0 1,5 2,0Per
mea
te f
lux
((l/m
2 .h)
Fc
pH (=3.22; acid)
pH (=5.81; natural)
pH (=10.09; alkaline)
31
11. Mukkar, H.P.S., Blummel, M., Borowy, M., and Becker, N.K., J of the Sci. of Food and Agric., 61, 161, 1993.
12
Acknowledgements Thanks are due to FCT and FEDER for funding the Project (PTDC/AGR-AAM/102042/2008) and Nicole Canto also thanks FCT and FEDER for their Master grants.
32
Application of electrocoagulation in sanitary landfill leachate treatment
A. Fernandes, D. Norma, M.J. Pacheco, L. Ciríaco, A. Lopes
UMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal
Abstract
The application of electrocoagulation, as a post-treatment, in the removal of organic load from a leachate collected in an intermunicipal sanitary landfill was evaluated. In order to understand the influence of the anode material in the electrocoagulation results, two different types of consumable anodes were used: iron and aluminum. Assays were run at constant applied potential, at natural initial pH. Slightly better results in the COD removal were obtained in the electrocoagulation performed with the iron anodes. The assays run with iron anodes also present lower energetic consumptions per mass of COD removed. However, when COD removed by mass of metal consumed is compared, the best results were obtained when aluminum consumable anodes were used.
Introduction
Leachate generation is an inevitable consequence of the deposition of solid wastes (MSW) in sanitary landfills, and is the result of water percolation trough wastes, that extracts and brings with it several pollutant materials [1]. This way, sanitary landfill leachate composition is very complex and varied and depends primarily on: the type of solid wastes that are deposited, the climatic conditions and the age of the sanitary landfill [1]. Inadequate leachate management involves considerable risks, particularly contamination of water resources (at the surface and groundwater) and soil [2]. In Portugal, a common treatment for sanitary landfill leachates comprises biological reactors with nitrification / denitrification steps, followed by membrane technologies. However, due to variability in the quality and quantity of leachate throughout the life span of the treatment plant, these conventional treatments become ineffective, so it is necessary to implement technologies that can be adjusted to in situ needs [2]. Electrochemical technologies have shown high efficiency in the elimination of persistent pollutants. Several studies have described the application of electrochemical methods in wastewater treatment [3-5]. Electrocoagulation is an electrochemical technology that can be applied in pollution abatement from liquid effluents. Its application, characterized by its simple equipment, easy operation and decrease in the amount of sludge, has also been studied in the treatment of sanitary landfill leachates, with very promising results [6,7]. The aim of this work was to study the application of electrocoagulation as a post-treatment of sanitary landfill
leachates, using two different consumable anode materials: iron and aluminum. The leachate samples used in this study were collected from an intermunicipal sanitary landfill. The treatment performed at the sanitary landfill comprises a biological step, followed by an ultrafiltration operation. Since the ultrafiltration permeate still presents a high organic load, samples collected in this point of the treatment plant were used in this study.
Materials and Methods
Electrocoagulation experiments were conducted in batch mode, without stirring and using 1L of leachate at natural pH. Two different anode materials were tested, aluminum an iron. All experiments were conducted with an applied voltage of 5.0 V, at room temperature (22-25 ºC) and without addition of background electrolyte. Electrocoagulated samples started to precipitate after elapsed times between 60 and 80 minutes. At that time, current was turned off, the formed flocks were allowed to settle, and the suspension was decanted and subjected to filtration. Assays run were followed by Chemical Oxygen Demand (COD) tests, using the closed reflux dichromate titrimetric method [8], and by suspended (SS) and dissolved solids (DS) measurements, performed according to standard procedures [8].
Results and Discussion
Table 1 presents the initial values for the parameters COD, SS and DS for the raw leachate collected at the sanitary landfill. Table 1. COD, SS and DS for the raw sample collected at the ultrafiltration permeate.
COD / mg O2 L
-1 SS / g L-1
DS / g L-1
2605 0.43 11.33
Figure 1 presents the normalized COD, SS and DS variation for the electrocoagulation assays performed with both anode materials, iron and aluminium. It can be observed that electrocoagulation with iron promotes slightly higher removals of COD, but SS and DS are barely affected. With aluminium anodes, an increase in SS and a decrease in DS were obtained, which may lead to a more easy removal of the undesirable material.
33
In Figure 2 the ratios of COD removed by energy consumed (a) and by mass of metal consumed (b) are presented. From an energetic point of view, the removal of COD can be favored by the use of iron electrodes, since the mass of organic load removed by unit of energy consumed when iron electrodes are used is twice the value obtained when aluminum anodes are used. However, higher removals of COD can be obtained with lower quantities of metallic ions when aluminum is the consumable anode material. These results must be related with the oxidation state of the different ions formed during the electrodegradation: On one hand, less energy is required to form the iron ions, which are divalent, while the aluminum ions are trivalent, but on the other hand, the trivalent ions promote flocculation of dissolved and suspended materials more easily, requiring lesser amount of material to perform similar reductions in the organic load.
Figure 1. Normalized COD, SS and DS variation for the electrocoagulation assays performed with two different anode materials, iron and aluminium, at an applied potential of 5.0 V, natural pH ( 8) and without stirring.
Conclusions
According to the obtained results, it seems feasible the application of electrocoagulation as a post-treatment of the ultrafiltration permeate from leachates of sanitary landfills to reduce the organic load. Between the two anode materials studied, iron presented the best energetic results, achieving a COD removal of 185.5 g per kW h of energy consumed. However, this result is obtained with higher consumption of metal ion than would be necessary if aluminum was used.
Figure 2. Ratios between COD removed and the energy consumption (a) or metal consumption (b) obtained in the electrocoagulation assays performed with two different anode materials, iron and aluminium, at an applied potential of 5.0 V, natural pH ( 8) and without stirring.
Acknowledgements
Financial support from FEDER, through Programa Operacional Factores de Competitividade – COMPETE, and FCT, for the project PTDC/AAC-AMB/103112/2008, and ICI-Santander Totta Investigação, for the grant awarded to A. Fernandes, are gratefully acknowledged.
References
1. Eggen, T., Moeder, M., and Arukwe, A., Sci. Total Environ, 408, 5147, 2010.
2. Santos, I., Diagnóstico e avaliação da gestão de lixiviados produzidos em aterros sanitários de resíduos urbanos. M.Sc. Dissertation, Faculty of Science and Technology, University Nova de Lisboa, 2008.
3. Chen, G., Sep. Purif. Technol, 38, 11, 2004. 4. Martínez-Huitle, C.A., and Ferro, S., Chem. Soc. Rev,
35, 1324, 2006. 5. Comninellis, C., Kapalka, A., Malato, S., Parsons, S.A.,
Poulios, I., and Mantzavinos, D., J. Chem. Technol. Biotechnol, 83, 769, 2008.
6. Ilhan, F., Kurt, U., Apaydin, O., and Gonullu, M., J. Hazard. Mat, 154, 381, 2008.
7. Labanowski, J., Pallier, V., and Feuillade-Cathalifaud, G., J. Hazard. Mat, 179, 166, 2010.
8. Eaton, A., Clesceri, L., and Greenberg, A., Standard Methods for Examination of Water and Wastewater. APHA, AWWA, WEF, 21st Ed., Washington, 2005.
34
Effect of continuous post-setting on crystallinity and thermomechanical behaviour of False-Twist Textured Polylactide multifilaments
A. M. Manich¹, J. Carilla¹, D. López-Santana¹, B. Baena¹, M. Riba², R Prieto², L. Montero², D. Cayuela2
¹IQAC-CSIC, Barcelona (Spain), ²INTEXTER-UPC, Terrassa (Spain)
Abstract
Polylactide (PLA) multifilaments, false-twist textured at different temperatures (135, 150 and 165ºC) and draw ratios (1.30, 1.35 and 1.40) have been stabilized by a continuous post setting treatment at 50 m/min and 100ºC using a specially designed chamber. The crystallinity of the original textured filaments and those of the stabilized ones has been measured. The effect of post setting on the thermomechanical behaviour according to the texturing conditions has been studied. The relationship between crystallinity and both relaxation shrinkage and maximum phase lag temperature have been pointed out.
Introduction
Polylactide (PLA) is a biodegradable and compostable polymer obtained from annually renewable resources [1]. Its physical properties and structure have been studied by several researchers, confirming that this polymer has significant commercial potential as a textile fibre [2]. From studies, and bearing in mind that polylactide fibres are thermoplastic, their microstructure could vary when subjected to the different textile manufacturing processes. PLA fibres are normally produced by melt extrusion. The effects of draw ratio and draw roll temperature on the orientation, crystallinity and mechanical properties of spun filaments have been studied [3]. When filaments are spun at 2500-3000 m/min, a POY multifilament yarn is obtained. POY yarns are usually textured to convert flat filament yarn into crimped fibres to simulate the properties of natural staple fibre yarns. Different temperature, draw ratio, friction and yarn speed will result in yarns with different bulkiness, elasticity and brightness. As regards the false-twist texturing the two main variables that could influence the shrinkage force of the filaments are pre-texturing draw ratio and temperature. The influence of these variables on the microstructure of the textured filaments has been studied in a previous paper [4]. As PLA textured yarns show a high tendency to shrink, they require a second setting or stabilization (post setting) treatment to reduce shrinkage in subsequent processing. When dyeing must be carried out in package dyeing, stabilization process in continuous needs to be done in order to confer good textile properties to the substrate. The effect of a stabilization process by reheating at 100ºC the textured yarn in continuous has not been considered up to now. Consequently, the influence of this process on crystallinity and thermomechanical
transitions and the possible relationships between them is presented in this paper.
Materials and Methods
Polylactide filament yarns, supplied by Anglés Textil S.A. were used. The polymer is polylactide for fibres grade with a melting point about 165ºC. A 167dtex/68 filament POY yarn was textured at different temperatures (135, 150, 165ºC) and draw ratios (1.30, 1.35, 1.40). Table 1 shows the sample references and the draw ratio and temperatures at which they were false-twist textured.
Table 1 Reference, draw ratio DR and texturing temperature TT of the 167dtex/68 polylactide multifilament
Ref DR TT Ref DR TT A1 A2 A3 B1
1.30 1.30 1.30 1.35
135ºC 150ºC 165ºC 135ºC
B2 B3 C1 C2
1.35 1.35 1.40 1.40
150ºC 165ºC 135ºC 150ºC
All textured filaments are stabilized passing through the chamber plot in Figure 1 at 50m/min. The chamber is at 100ºC and the draw ratio applied to the filament is 1.07.
Figure 1 Prototype for continuous stabilization of PLA.
The DSC analysis was obtained under the following conditions: initial temperature 50ºC, final temperature
-1 and nitrogen purging gas -²). By comparing the melting enthalpy of the
-1), the percentage of crystallinity (XDSC) was calculated through the
35
relationship XDSC the melting enthalpy of the substrate and 93.6 the melting enthalpy of a perfect polylactide crystal in J/g [5,6].
Two samples of each reference (Table 1) 12.8 mm in length were tested in a TMA/SDTA 840 Mettler Toledo at the following conditions: Initial temperature 25ºC, final temperature 165ºC, heating rate 5ºC.min-1, nitrogen purging gas 35 mL min-1 under a periodic load between 0.025 and 0.05 N at 1/12 Hz. Variations in length given by TMA resembled that in Fig. 2. The Onset temperature Tso (ºC), the peak temperature Tsp (ºC) of shrinkage, the relaxation shrinkage Sr (%) at Tsp, the endset temperature of shrinkage Tse (ºC) the linear expansion coefficient
-1 K-1) and the maximum were determined [4] by
analyzing the mean curve of the variation in length and the storage and loss modulus with temperature.
Figure 2 TMA plot of PLA multifilament from 25 to 165ºC at 5ºC/min. Periodic load between 0.025 to 0.05 N at 1/12 Hz.
Results and Discussion
Results of crystallinity and thermomechanical analysis for textured and stabilized filaments are shown in Table 2.
Table 2 Crystallinity XDSC, onset temp Tso, peak temp Tsp of shrinkage, relaxation shrinkage Sr, endset temp of shrinkage Tse and linear expansion coeff between 50 and
Ref. XDSC
% Tso ºC
Tsp ºC
Sr %
Tse ºC
ppm/K
ºC
Textured: A1 A2 A3 B1 B2 B3 C1 C2
24.8 26.1 30.5 26.2 29.5 33.4 26.9 31.1
64.8 64.8 64.6 65.0 64.9 64.7 64.8 64.9
70.5 70.8 71.5 70.9 71.6 72.4 71.7 72.6
17.97 15.70 13.33 14.97 13.23 11.36 11.48 10.36
77.8 78.4 79.8 78.6 80.2 82.0 80.1 82.0
645.2 640.0 593.7 697.3 657.5 584.8 676.8 630.5
67.5 68.1 68.7 67.8 68.5 69.0 68.5 68.7
Stabilized: A1 A2 A3 B1 B2 B3 C1 C2
49.8 51.4 51.1 52.6 52.7 51.7 48.4 50.7
65.0 65.5 65.4 64.9 65.6 65.3 65.4 65.5
72.1 74.0 72.6 72.9 74.5 74.4 74.0 74.8
1.49 0.90 0.64 1.16 0.99 1.64 0.67 1.65
83.5 87.3 86.0 85.7 86.9 86.1 86.7 86.9
570.8 557.5 628.4 526.2 491.0 445.7 525.9 436.8
71.0 72.3 71.7 72.2 72.8 72.1 72.7 72.9
The influence of the texturing variables on each response y was analysed by regression analysis fitting the empirical model y = b0 ibi xi ijbij xi xj x1 the texturing temperature and x2 the draw ratio. The application of the Analysis of Variance [7] enabled us to remove the non-significant variables from the model to
about the influence of stabilization and texturing variables on crystallinity and thermomechanical behaviour will be based on the surface responses given by the empirical models all of them significant to 0.1%, that includes only the significant effects, although, for the sake of brevity, the regression equations and the determination coefficients will not be given.
Figure 3 shows the influence of continuous stabilization treatment and texturing variables on crystallinity. Stabilization increases crystallinity specially that of the slightly textured filaments, regardless the initial crystallinity of the textured filaments, which ascends with texturing intensity. After post setting all filaments reached crystallinities around 50%. The stabilization would have tempered the big differences found on textured substrates.
Figure 3 Crystallinity of textured & stabilized PLA filaments.
The onset temperature of shrinkage is associated with the onset temperature of glass transition [4]. Although the
onset temperature of shrinkage, the stabilization treatment increases Tso from 64.8±0.1ºC to 65.3±0.2ºC. The relaxation shrinkage Sr measures the maximum retraction attained by the filament due to the increase in temperature that approaches the ordered, extended conformation of the amorphous domains into a more random coil configuration. This occurs when temperature comes close to the peak temperature of shrinkage that can be associated with the characteristic temperature at which every non-crystalline chain segment can relax from a lower entropy to a higher entropic state resulting in shrinkage [9]. The influence of stabilization and texturing variables on the peak temperature of shrinkage and on the relaxation shrinkage are shown respectively in Figures 4 and 5.
The peak temperature of shrinkage at which the maximum mobility of the amorphous domains is attained increases with the stabilization treatment although the positive influence of texturing variables (DR and TT) remains.
36
Figure 4 Peak Temperature of shrinkage of PLA filaments.
As regards the relaxation shrinkage the effect of the stabilization increases as the texturing intensity decreases. It balances the effect of texturing on the relaxation shrinkage leading the slighter textured filaments to the lower relaxation shrinkage while the stronger textured (higher temperature and draw ratio) are lead to higher relaxation.
Figure 5 Relaxation shrinkage of PLA filaments.
Figure 6 shows the influence of the stabilization on the endset temperature of shrinkage and Figure 7 on the linear expansion coefficient from 50 to 150ºC according to the texturing variables. As observed in a previous paper [4], the cold crystallization in PLA mainly occurs from the peak temperature of shrinkage to the endset temperature of shrinkage. Stabilization increases the peak temperature of shrinkage about 2.5ºC while the endset temperature of shrinkage is increased by 6ºC while the influence of texturing conditions remains.
Figure 6 Endset temperature of shrinkage of PLA filaments.
As regards the dimensional stability the effectiveness of the stabilization treatment is greatly favoured by the
intensity of texturing being the filaments textured at the highest temperature and draw ratio those that the decrease in the linear expansion coefficient were the highest.
Figure 7 Linear expansion coefficient of PLA filaments.
The analysis of E-storage and E-loss curves resulting from the periodical load applied enabled us to determine
two components of the modulus at which the maximum dissipation in energy by internal reordering in the amorphous phase is produced [10]. This can be use as a measure of the glass transition temperature of the filament. Figure 8 shows the influence of texturing i -setting on it. After stabilization the influence of texturing
draw ratio remains. The effect of stabilization on the increase in glass transition decreases with texturing intensity.
Figure 8 Temperature of maximum phase lag between E-storage and E-loss of PLA filaments.
Relationship between relaxation shrinkage, temperature of maximum phase lag between E-storage and E-loss and crystallinity
Figure 9 shows the relationship between crystallinity and relaxation shrinkage that is explained by the following equation:
Sr = 29.27 0.55 XDSC (r = -0.981) being Sr the relaxation shrinkage (%) at the peak temperature of shrinkage and XDSC the crystallinity (%) measured by the DSC. It seems relevant that the higher the crystallinity and also the orientation, the lower the maximum retraction attained by the filament when the
37
amorphous domains are approached from the ordered, extended conformation to a maximum random coil configuration. This occurs at the peak temperature of shrinkage that is associated with the characteristic temperature at which every non-crystalline chain segment can relax from a lower entropy to a higher entropic state resulting in shrinkage.
Figure 9 Relationship between crystallinity and relaxation
shrinkage of PLA textured and stabilized filaments.
When crystallinity attains levels higher than 48% due to stabilization, the relaxation shrinkage at Tsp results less than 2%.
Figure 10 shows the relationship between crystallinity and the temperature of maximum phase lag that is explained by the following equation:
0.17 XDSC (r = 0.974)
E-storage and E-loss (ºC) and XDSC the crystallinity (%) measured by the DSC. It seems relevant that the higher the glass transition temperature of the filaments.
Figure 10 Relationship between crystallinity and temperature of maximum phase lag of PLA textured and stabilized filaments.
Crystallinity and glass transition shows a very relevant positive relationship. When crystallinity attains levels near 50% orientation plays a more important role on the increase of glass transition.
Conclusions
Stabilization significantly increases both the bonding level of the amorphous phase and the crystallinity of the false-twist textured PLA filaments.
Stabilization greatly modifies the thermomechanical behaviour of the filaments: The onset temperature of shrinkage (glass transition) slightly increases, the peak temperature of shrinkage ascends and the relaxation shrinkage is reduced specially for the slight textured filaments; the endset temperature of shrinkage grows with stabilization and the linear expansion coefficient between 50 and 150ºC is greatly reduced after stabilization specially for the highly textured filaments. When crystallinity attains levels of 49% the relaxation shrinkage is less than 2% while the orientation induced by draw ratio plays a more important role on the increase of the maximum phase lag temperature (glass transition). References
1. Farrington, D.W.; Lunt, J.; Davies, S.; Blackburn, S.R.: Poly(lactic acid) fibers, In Biodegradable and sustainable fibres. Woodhead Publishing Limited, ISBN 13:978-1-85573-916-1, 2005.
2. Farrington, D.W.; Lunt, J.; Davies, S.; Blackburn, S.R.: Poly(lactic acid) fibers, In Biodegradable and sustainable fibres. Woodhead Publishing Limited, ISBN 13:978-1-85573-916-1, 2005
3. Solarski S., Ferreira M., Devaux E. Thermal and mechanical characteristics of polylactide filaments drawn at different temperatures. J Text Inst. 98: 22736, 2007.
4. Manich A. M., Carilla J., Miguel R. A. L., Lucas J. M., Franco F. G. F., Montero L. A., Cayuela D., Thermal transitions of polylactide false-twist textured multifilaments determined by DSC and TMA, J Therm Anal Calorim, 99, 3, 723-731, 2010.
5. Fischer E.W., Sterzel H.J. and Wegner G. Investigation of the structure of solution grown crystals of lactide copolymers by means of chemical reactions, Kolloid Z. u. Z. 251: 980-990, 1973.
6. Wunderlich B. Thermal Analysis, Academic Press; 1990, 280
7. Montgomery D. C. Design and analysis of experiments, 5th ed, New York, J Wiley & Sons, pp 194-201
8. Draper N R and Smith H. Applied Regression Analysis, 2nd. Ed. New York: J Wiley & Sons, pp. 294-311
9. Buchanan D. R. Thermomechanical responses of Fibres
Mukhopadhyay S K. The Textile Institute, Manchester, 1992
10. Manich A. M., Miguel R., Lucas J., Franco F., Baena B., Carilla, J., Montero L., Cayuela D., Texturing, stretching and relaxation behaviour of polylactide multifilament yarns, Text. Res. J., 81(17) 1788-1795, 2011
Acknowledgements
Authors are indebted to the Spanish project MAT2010-20324-C02-02 for funding. They also express their gratitude to the company Anglés Textil, S.A. (ANTEX) for their generous help in providing and preparing the textured samples.
38
Sensory Analysis: A New Tool to Characterize Textile Materials
M. E. Cabeço-Silva 1, C. Nogueira 1
1Centro de Ciência e Tecnologia Têxtil
Abstract
Studies demonstrate that the first sense that is activated at the moment of a textile product acquiring is the vision.
unconsciously to decide for a specific material. It is of main importance for the manufactures to know which touch and vision describers are evaluated at the moment of their appreciation. Therefore, they can develop their
expectations. Being touch and vision subjective parameters, this work uses the sensory analysis methodology to quantify them. In this study the sensory analysis was used to define the touch and vision describers.
Introduction
Sensory analysis is a methodology that uses human sensors to characterize, measure, analyze and interpret the reactions of and the way they are understood. 1 The sensory apparel does not depended only of the vision, touch, smell, taste and audition senses; it depends also of the memories, expectations and education. Is not only one sense that acts on the perception of a textile product; the senses are combined and are their connections that give the final result. It is possible to apply sensory analysis, normally used in other industries like food, cosmetics or automobile, to the textile and clothing industry using the man and studying the influence of touch and vision at the moment of clothing acquirement. In ordeevaluation it is of main importance to act at the moment of product conception focusing on the most desired
2, 3
This methodology can be a great tool for the production and design sectors in the search for the development of
vision. It allows also to study the production processes and to change them taking into account the organoleptic properties of the product. This will improve the quality of the products and help the quality control during process production, allowing the increment of a long life product.
touch, is essentially a result of how much stress is generated in the material and how it is distributed over the skin and, consequently, has a strong relationship with both mechanical and surface properties of the fabric. 4 The vision requires the intervention of specialized areas of the brain (visual cortex) that analyze and synthesize the information assembled in terms of shape, colour, texture and relief. These evaluations involve subjective and objective properties of nature that can be evaluated by psycho or physic tests/instruments in order to find the best compromise between them. Analysis to textile and clothing industry allows to define the attractively and acceptation of the final product,
Materials and Methods
In this study, it was created a panel composed by a group of free volunteers, called assessors that described the touch and vision perception of textiles using describers (attributes). The panel of sensorial evaluators is an heterogeneous group with different personal experiences, scholarship and different areas of knowledge.
Textiles materials In this work, textiles with different structures were selected.
Fig. 1: Materials used of sensory analysis touch was 26 and 102 samples for vision.
39
These samples were all finished products in order to simulate the final product of the basic consumer. These samples included natural fibers (cotton, wool, flax, silk) and synthetic fibers (polyester, polyamide, polyethylene and mixtures of fibers) with different textiles technologies (plain, twill, satin, plain weave), knitted fabrics (interlock, jersey, polar) and nonwovens (spunlaid, drylaid, wetlaid, meltblown and SMS). Beside the different structures of materials, were also included different colour materials, different patterns and different printed materials. The number of materials used of sensory analysis for touch was 26 and 102 samples for vision. Experiment conditions Control of humidity; Control of temperature; Light chamber; One fabric at a time; Disposable towel; Soap with neutral pH; Limited duration of each session: 30 min.
Fig. 2: Touch box (1) and vision box (2). Experimental plan The assessor panels analyzed the different materials in a standard atmosphere (65 ± 2% relative humidity and 20 ± 2ºC temperature). In order to avoid the decrease of sensitivity of the evaluators that could occur after a long period of evaluation, each session was limited to 30 minutes. The final attributes were chosen taking into account the results obtained from three different stages. It was performed an inquest where the assessors described using free vocabulary
Results A list of total attributes was achieved using all the words described by the evaluators for the samples. Several attributes were eliminated, using a logical process that is explained further, in order to obtain a smaller list which contained the final attributes. First attributes selection The first selection of attributes was achieved using the panel contribution and the procedure was followed by the eliminating of: 5
Hedonic terms; Attributes that described final material applications; Descriptions corresponding to material
characterization; Non pertinent terms mentioned like personal
experiences; Non quantifying terms such as resistant or absorbent; Attributes that were not similarly described by the
panel (e.g. rubbing); Ones that are related with other sensing like touch or
audition according to the NF-ISO 11035, 95 standard procedure. 6
After this procedure it was attained a list of attributes which were joined, with the panel collaboration, according to the real final meaning. For the same final attribute, different evaluators used different describing words; therefore, a standardization of each attribute was performed, according to the BP X 10-042 standard method 7 , by joining the similar words and choosing the one that was considered the best describer. The final attributes attained are presented in the Table 1. Second attributes selection The lists of attributes previously attained were submitted to the panel evaluation. Each member of the panel classified these describers using a 0-5 scale (0-no sensation, 5-high sensation). 8 After this evaluation, the frequency and intensity of each attribute were determined. The statistical analysis of principal components (PCA) was performed in order to join, the similar attributes (positive correlation) and the opposite attributes (negative correlation) that allowed the elimination of attributes with less significance and detach the main differences between them. In addition, a correlation circle was constructed allowing the identification of the antagonist and similar terms considered by the panel. From the correlation circle obtained it was possible to identify the bipolar terms that are described below. By the observation of the correlation circle it was possible to group the variables, according to the high positive correlations, taking into account the proximity and common properties, showing homogeneity in each group and heterogeneity between other groups. Therefore, the groups were formed and the selection of bipolar attributes was performed. The attribute which better represented the description of the parameter in analysis was chosen giving place to the bipolar attributes selection when the describers were antagonist. Therefore, the antagonist attributes that originated bipolar terms were.
1 2
40
Table 1 - Touch and Vision Attributes
Sense Touch (15) Vision (10)
Attributes
Cold-Warm
Thin-Thick
Heavy-Light
Supple-Rigid
Pilous
Slippery
Stick
Granulous
Failing
Crumple
Elastic Rough-Smooth Sleek-Rugous
Shape Recovery Fluffy
Brightness
Cold- Warm
Fluffy
Pilous
Rough - Smooth
Sleek - Rugous
Thin-Thick
Tight - Loose structure
Transparent
Uniformity
Conclusions
The methodology used to define the best attributes is suitable to describe touch and vision sensations. The panel selected was able to decide by unanimity the attributes, and the statistical tool used was useful at the moment of attributes chosen. At the end of the study, it is possible conclude that the touch and vision is still a subjective parameter of complex evaluation.
References
1. IFT, Sensory evaluation guide for testing food and beverage products. Sensory. Evaluation Division. Institute of Food Technologists. Food Technology, 1981. 35(11): p. 50-59.
2. F. Philippe, L. Schacher, D. Adolphe (2003). Tactile Feeling: Sensory Analysis Applied to Textile Goods, Textile Research Journal, Vol.74, p.1066-1072.
3. Nogueira, Clarinda, Cabeço-Silva, Maria Elisabete, Schacher, Laurence and Adolphe, Dominique (2008). Sensory Analysis: A Practical Approach for Textile Materials Characterization; Proceedings of 4th International Textile, Clothing & Design Conference - Magic World of Textiles, Dubrovnik, Croatia, Book of proceedings, pp.854-858.
4. George Havenith (2003). Clothing and Thermoregulation in Elsner P, Hatch K, Wigger- Alberti W (eds): Textiles and the Skin. Current problems in dermatology Switzerland. Basel, Karger, Vol.31 pp.35-49; ISBN 3-8055-7438-X.
5. Nogueira, Clarinda, Cabeço-Silva, Maria Elisabete, Schacher, Laurence and Adolphe, Dominique (2009). Textile Materials: Tactile Describers, Journal of Food Technology 7(3): 66-70, ISSN: 1684-8462.
6. International Standard ISO 11035:1994, Sensory Analysis - Identification and Selection of Descriptors for Establishing a Sensory Profile by a Multidimensional Approach. 1994.
7. AFNOR, BP X 10-042, in Référentiel de Bonnes Pratiques. Caractérisation Sensorielle des Matériaux. Recommandations Pratiques pour l'Analyse Visuelle de la Matière Première du Produit Fini. 2006, Avril.
8. C. Nogueira, M. E. Cabeço-Silva, L. Schacher, D. Adolphe (2008). Structured or Non-structured scale: What is the best scale for the human sensation measurement? Proceedings of International Conference o Applied Research in Textile; CIRAT-3, Sousse (Tunisia). Book of proceedings, pp. 361-365.
41
Separation of plasmid DNA from non clarified lysate impurities using berenil as ligand in pseudo-affinity chromatography
C. Caramelo-Nunes1,2, M.F. Gabriel1,2, P. Almeida1,2, J.C. Marcos3, C.T. Tomaz1,2
1 CICS-UBI – Health Sciences Research Centre, University of Beira Interior,Av. Infante D. Henrique, 6200-506 Covilhã, Portugal, 2 Department of Chemistry, University of Beira Interior, Rua Marquês d’Ávila e Bolama,
6201-001 Covilhã, Portugal, 3 Center of Chemistry, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
Abstract
Small molecules that bind to DNA with high specificity represent a relevant alternative as ligands in affinity and pseudo-affinity chromatographic processes for plasmid DNA (pDNA) purification. In the present study, berenil was applied as ligand to specifically purify pDNA from non-clarified E. coli process streams without a previous precipitation step with ammonium sulphate. A substantial decrease in the levels of contaminants was observed using 1.3 M sulphate ammonium in the eluent, followed by a decrease in salt concentration by a stepwise mode to 0.55 and then to 0 M. The proteins were completely removed from the sample after one run through the berenil derivatized support, without the need of the salt clarification step. The low molecular weight RNA was also completely eliminated. Additionally, a pure pDNA sample according to specifications of regulatory agencies was obtained after a second chromatographic run on the berenil-Sepharose column.
Introduction
Molecular therapy approaches using non-viral vectors are becoming the chosen strategy to treat various types of diseases using naked DNA as the vehicle for the introduction of the therapeutic gene.1,2 For this reason, the expected wide application of these vectors requires a large-scale production and purification of pDNA. Recent years have witnessed an increasing research effort in the development of new methods for plasmid purification, most of them based on chromatography processes.3 The resulting product must meet stringent quality criteria in terms of purity, potency, efficacy and safety, established by the Regulatory Agencies. However, similarities between most of the critical contaminants and pDNA can cause difficulties in their separation process.4 The use of affinity ligands can be a simple and efficient way to overcome this problem.5,6 Berenil or 1,3-bis(4-phenylamidinium) triazene is an aromatic diamidine recently applied as ligand for the chromatographic separation of the supercoiled (sc) plasmid isoform from the less active open circular (oc) isoform.6 In this study is reported a pseudo-affinity chromatographic technique to purify pDNA directly from non-clarified E. coli process streams and aims to shed some light on the ability of this
new support to separate and purify pDNA from the most critical contaminants without recurring to the common clarification step with ammonium sulphate.
Materials and Methods
Escherichia coli DH5 α strain harbouring 6.05 Kpb plasmid pVax1-LacZ (Invitrogene, Carlsband, CA, USA) was cultured and grown according to previous work.6 Plasmid-free E. coli cells were also grown under the same conditions,6 but with no antibiotic present. Cells harbouring the plasmid were lysed using a modification of the alkaline method proposed by Sambrook et al.7 as previously described,8 with no clarification step with ammonium sulphate. Sepharose CL-6B (Amersham Biosciences, Uppsala, Sweden) was epoxi-activated according to the method described by Sundberg and Porath9 and coupled to berenil as described before.6 A 10x10-mm column (Amersham Biosciences, Uppsala, Sweden) was packed with 2 mL berenil-derivatized support and connected to a Fast Protein Liquid Chromatography (FPLC) system (Amersham Biosciences, Uppsala, Sweden). The column was then equilibrated with 1.3 M ammonium sulphate in 10 mM Tris-HCl buffer (pH 8.0) at a flow rate of 1 mL/min. Non-clarified samples (25 μL) with a nucleic acid concentration of 600 μg/mL in equilibration buffer were loaded onto the column at the same flow rate. The elution of bonded species was promoted by decreasing the ionic strength to 0.55 M ammonium sulphate in 10 mM Tris-HCl buffer (pH 8.0) and afterwards to 0 M. The absorbance was continuously monitored at 280 nm. Fractions were pooled according to the chromatograms obtained, concentrated and desalted using Vivaspin concentrators (Vivascience). A second chromatographic run was performed injecting the concentrated fraction, pooled after the first run, in the same binding and elution conditions. After the chromatographic runs, the column was washed with at least 5 bed volumes of deionised water. Both pooled fractions and feed samples were analysed by different methods: horizontal electrophoresis as described before,6 high-performance liquid chromatography (HPLC) according to the method described by Diogo et al.,10 calculation of protein concentration using the micro-bicinchoninic acid (BCA) assay from Pierce (Rockford, USA), according to the manufacturer’s instructions,
42
analysis of endotoxin contamination using the ToxinSensor™ Chromogenic LAL Endotoxin Assay kit from GenScript (GenScript USA Inc., New Jersey, USA), according to the manufacturer’s instructions, finally, the genomic DNA contamination was assessed using real-time polymerase chain reaction (PCR) in a iQ5 Multicolor Real-Time PCR Detection System (Bio-Rad), according to the method described by Martins et al..11 E. coli genomic DNA was purified with the Wizard gDNA purification kit (Promega).
Results and Discussion
The present study reports a pseudo-affinity chromatographic technique to separate and purify pDNA directly from non-clarified E. coli process streams. This is accomplished without the standard clarification step with a relatively high ammonium sulphate concentration. In a first run, 600 μg/mL of feedstock sample (25 μL) were injected onto the berenil-Sepharose column with 1.3M of ammonium sulphate in the eluent. The chromatographic profile obtained is shown in Fig. 1A, as well as the agarose gel electrophoresis analysis of the pDNA eluted fractions.
Figure 1. Chromatographic separation of pDNA on berenil-Sepharose column: (A) After one run through the support and agarose gel electrophoresis analysis of the eluted fractions, 1 - pDNA eluted with 0.55M (NH4)2SO4 and 2 – RNA eluted with 0M (NH4)2SO4; (B) After the second run through the berenil support. The electrophoresis shows that the pDNA fraction still contains a slight RNA contamination, even though the great majority of this contaminant clearly elutes in the second peak, when the ammonium sulphate concentration is decreased to zero. In a second run, the pDNA fraction
obtained after one chromatographic run was concentrated and injected onto the berenil-Sepharose column in the same buffer conditions. The chromatogram obtained (Fig. 1B) shows two well defined peaks, the first corresponding to the elution of pDNA by decreasing the salt concentration to 0.55M and a second peak corresponding to all the contaminants with higher hydrophobicity, eluted after decreasing the salt concentration to 0M. The quality of the plasmid fractions was examined by determination of process parameters such as yield and purity (Table 1) using HPLC analysis, quantification of proteins, endotoxins and gDNA (Table 2). Table 1. HPLC analysis of purity and recovery yield of pDNA fractions.
Method Process Step
Purity (%)
Purification Factor
Yield (%)
Injected Feed
4.4 - - After one run through the column pDNA
fraction 16.2 3.7 71
Injected Feed
4.4 - - After two runs
through the column
pDNA fraction
100 22.7 33
As shown by agarose gel electrophoresis and confirmed by HPLC, the pDNA fraction still had a RNA contamination after only one chromatographic run. Even though the purification factor was around 3.7, the plasmid purity was still low (16.2%). However, the low molecular weight RNA was completely eliminated from the pDNA fraction. On the other hand, starting from a highly contaminated lysate (Table 2) and after two consecutive chromatographic runs, the pDNA fraction became free from RNA, with a purification factor of almost 23 (Table 1). Nevertheless, the yield (33%) is greatly lower than that obtained with only one run (71%). Proteins were not detected in any of the pDNA purified fractions, although the initial concentration of 1170 μg/ml detected in the feed solution (Table 2), indicating that berenil-Sepharose chromatographic step is extremely efficient in eliminating the protein contamination. After one chromatographic run, the gDNA content (Table 2) in the plasmid fraction was greatly reduced (24.9 fold). On the other hand, it was observed a dramatically reduction of 4309.3 fold of gDNA in the plasmid pool, subsequent to a second run through the berenil-Sepharose column. The efficiency of berenil-Sepharose support in reducing the endotoxin contamination (Table 2) was particularly noteworthy, since a 169.2-fold reduction was obtained after a single chromatographic run and a remarkable 676.7-fold reduction after two runs.
43
Table 2. Quantitative analysis of the pDNA, proteins, RNA, endotoxins and gDNA in injected feed and plasmid sample after berenil-sepharose chromatography.
Method� Impurity Injected Feed
pDNA fraction
Reduction factor (fold)
Protein (μg/ml) 1170 Undetectable -
RNA (mass %)
95.6 83.8 1.1
Endotoxins (EU/ml) 2.03 0.012 169.2
After one run through
the column�
gDNA (μg/ml)
1068.7 43 24.9
Protein (μg/ml) 1170 Undetectable -
RNA (mass %) 95.6 Undetectable -
Endotoxins (EU/ml) 2.03 0.003 676.7
After two runs
through the
column�gDNA (μg/ml) 1068.7 2.4x10-3 4309.3
The comparison between the pDNA sample composition, collected after the second chromatographic run (Table 2), and FDA specifications12 showed that the values are in accordance to the requirements for molecular therapy products.
Conclusions
This study showed that after one run through the berenil-Sepharose column, the proteins and the low molecular weight RNA were completely removed from E. Coli lysate samples, without the standard clarification step with ammonium sulphate. Moreover, all the other contaminants, including the high molecular weight RNA, were also greatly diminished, despite pDNA was not completely purified. Alternatively, after two consecutive runs through the berenil column, the pDNA sample was completely purified from the process stream impurities, using smaller amounts of salt in the eluent than those usually used in pseudo-affinity and hydrophobic chromatographic processes and more importantly, without the previously referred clarification step by salt precipitation. These results suggest that this chromatographic method could be a potential process of producing pharmaceutical grade pDNA for molecular therapy applications.
References
1. Signori E., Iurescia S., Massi E., Fioretti D., Chiarella P., De Robertis M., Rinaldi M., Tonon G. and Fazio V.M. Cancer Immunol. Immunother. 59, 1583, 2010.
2. Holladay C.A., O’Brien T. and Pandit A. WIREs Nanomed. Nanobiotechnol. 2, 232, 2010.
3. Diogo M.M., Queiroz J.A. and. Prazeres D.M, J. Chromatogr. A 1069, 3, 2005.
4. Stadler J., Lemmens R. and Nyhammar T., J. Gene Med. 6, 54, 2004.
5. Sousa F., Prazeres D.M. and Queiroz J.A., Trends Biotechnol. 26, 518, 2008.
6. Caramelo-Nunes C., Tente T., Almeida P., Marcos J.C. and Tomaz C.T., Anal. Biochem. 412, 153, 2011.
7. Sambrook J., Fritisch E.F. and Maniatis T., Molecular cloning: laboratory manual, Cold Spring Harbor Laboratory Press, New York, 2nd ed., 1989.
8. Diogo M.M., Queiroz J.A., Monteiro G.A., Martins S.A.M., Ferreira G.N.M. and Prazeres D.M.F., Biotechnol. Bioeng. 68, 576, 2000.
9. Sundberg L. and Porath J., J. Chromatogr. 90, 87, 1974. 10. Diogo M.M., Queiroz J.A. and Prazeres D.M.F., J.
Chromatogr. A, 998, 109, 2003. 11. Martins S.A., Prazeres, Cabral J.M. and Monteiro
G.A., Anal. Biochem. 322, 127, 2003. 12. FDA/CBER. Guidance for Industry: Considerations
for Plasmid DNA Vaccines for Infectious Disease Indications, Guidance document, 2007.
Acknowledgements
This work was supported by FCT, the Portuguese Foundation for Science and Technology PTDC/QUI-QUI/100896/2008. C. Caramelo-Nunes acknowledges a fellowship (SFRH/BD/64918/2009) from FCT.
44
Biodegradability of olive mill wastewaters
L. R. Fernandes, A. Gomes, A. Lopes, R. M. Simões
Unidade de Materiais Têxteis e Papeleiros
Universidade da Beira Interior
Abstract
Wastewater from a three phases olive mill in Castelo Branco (Portugal) was characterised and its aerobic biodegradability studied. The effluent has a very high organic load, with a total chemical oxygen demand of 127 g/L, and a total phenolic content of 6.5 g/L (as gallic acid). Without dilution, the aerobic microorganisms can not significantly degrade the organic load, but at 1:60 dilution their performance increase markedly. Ozone pretreatment enhances the process, even more.
Introduction In Mediterranean countries, the olive oil industry is very important, in both economic and tradition terms [1]. In resume, the process is based on the olive oil extraction by using a two or a three-phases centrifugation system, after mechanical grinding of the olives. The process results in the worldwide production of more than 30 millions m3 per year of black olive mill wastewater (OMW) [2]. The physicochemical properties of the OMW depends on factors such as method of extraction, type and maturity of olives, region or origin, climactic conditions and associated cultivation/processing methods [3]. Beside its high amounts of organic content (Chemical Oxygen Demand (COD): 37000-318000 mg/L, total suspended solids (TSS): 6000-69000 mg/L) [4-6], OMW contains high concentrations of recalcitrant compounds such as lignin and tannins (52270-180000 mg/L) which confer the dark color to the effluent. In addition, it contains phenolic compounds (500-24000 mg/L) and long chain fatty acids which are toxics to microorganisms and plants [7, 8]. These effluent properties make its treatment very difficult and several physicochemical and biological treatments, as well as their combinations, have been proposed. Biological methods used for OMW treatment are aerobic-activated sludge and anaerobic digestion. Usually, the first exhibit higher COD and phenolic compound removal efficiencies but the energy consumption in aeration is usually prohibitive [9, 10]. The process by which microbial organisms transform or alter (through metabolic or enzymatic action) the structure of chemicals introduced into the environment is defined as biodegradation; the biodegradation potential, also referred as biodegradability, can be measured as the ratio between the biochemical oxygen demand (BOD) and the chemical oxygen demand (COD) [11,12]. Literature review shows that in recent years there has been a growing interest in oxidation and advanced
oxidation processes for the treatment of industrial effluents [13, 14]. Ozone is a powerful oxidizing agent that selectively attacks compounds containing aromatic rings and double bonds. Lafi et al. [2] have shown that the pre-treatment with ozone enhance the biodegradability of OMW. The objective of the present paper is evaluating the effect of effluent dilution and ozone pretreatment on the aerobic biodegradability. Materials and Methods Olive mill wastewater OMW was obtained from a olive oil plant (three-phases centrifugal) located at Castelo Branco (Portugal). Immediately after sampling, the raw OMW was filtered in a 200 mesh screen and maintained at -18ºC during the experimentation period. Analytical methods
Several parameters were measured during the experiments. Total solids (TS), total suspended solids (TSS), total chemical oxygen demand (COD) and lipids were determined as proposed by Standard Methods [15]. Biochemical oxygen demand (BOD) was preformed according to the respirometric method (5210-D) described on Standard Methods [15], using Oxitop® bottles (WTW) and in some experiments pure oxygen instead of air. pH was measured using a 794 Basic Titrino (Metrhom AG). Total Phenols were determinated by Folin-colorimetric method [16].
Aerobic biotreatment
The bioreactors (operated in batch) were seeded with activated sludge obtained from the aeration tank of a biological wastewater treatment plant and kept in an synthetic municipal wastewater.
Ozone treatment Ozone treatment was performed in a 1.4 L closed jacketed glass vessel provided with a mechanical stirrer (rotor/stator type). One liter of diluted effluent with the appropriate initial COD concentration was introduced into the reactor. After stabilizing the ozone generator for several minutes, the ozone production was determined iodometrically. Afterwards, the ozone-containing gas was fed to the reactor at a fixed flow rate (usually 50 L/h) under vigorous agitation (1200 rpm). Liquid samples were withdrawn from the reactor at different reaction times. A Fischer Model 502 (Bonn, Germany) ozone generator was employed to produce ozone from dry, pure oxygen. The ozone concentration at the ozone generator output remains practically constant during the essay.
45
Figure 1 Schematic diagram of the experimental setup: (1) ozone generator, (2) ozone sensors, (3) mechanical stirrer, (4) Oxidation reactor, (5) KI trap, (6) data acquisition system.
Results and Discussion
OMW composition
The composition of the 200 mesh filtered olive mill wastewater (OMW) is resumed in Table 1. The main feature of the effluent is its very high organic load (total COD value) and the total phenolic compound content. These compounds are usually referred as inhibitor of some microorganisms. Table 1- Composition of OMW
Total solids, (TS) (g/L) 105
Total suspended solids, TSS (g/L) 32
Total dissolved solids, TSS (g/L)) 73
Total COD (g/L) 127
Total phenols (g/L, as galic acid) 6.5
Lipids (g/L) 0.77
pH 5.4
Effect of OMW initial COD concentration on biodegradability
This study was carried out in the usual Oxitop® flasks, with the same working volumes (50 mL) but with different dilution. The OMW filtered was diluted in order to test the effect of the initial COD concentration on the aerobic biodegradability, evaluated as the ratio between the biochemical oxygen demand, for a reaction time of 5 days (BOD5), and the chemical oxygen demand (COD), (BOD5/COD). As figure 2 shows, the biodegradability remains almost constant for a COD concentration up to 2000 mg/L, and decreases significantly for higher COD concentrations. It should be emphasized that the available oxygen in the flask reactors enables to attain a
maximum BOD close to 5000 mg/L (the total volume of the flask reactor is 310 mL and the working volume selected was 50 mL). It should be also noted that the oxygen consumption for the sample with an initial COD of 20000 mg/L is close to 2000 mg O2/L while the sample with an initial COD of 2000 mg/L (one order of magnitude lower) is around to 1000 mg O2/L, which reveals the marked effect of COD concentration on the aerobic biodegradability. Tziotzios et al. [9], working with olive pulp bacteria and monitoring the dissolved COD have reported much lower sensitivity to the OMW concentration in the COD range of 10000 50000 mg/L. Moreover, the soluble COD removal was in the range of 50 80%, for 5 days treatment. These values reach the 82 90% range for longer reaction times.
Figure 2 - Effect of initial COD concentration on the aerobic biodegradability of OMW
Impact of ozone treatment on COD of OMW
Filtered OMW was diluted until a COD of 1000 mg/L and treated with ozone at natural pH (5.4), and at pH 12 (results shown in Figure 3). At pH 12, the COD removal is substantial, reaching more than 75%, for high applied ozone charges/initial COD ratios, probably due to the production of hydroxyl radicals in the alkaline medium. At natural pH, on the contrary, both the COD removal and the ozone retention are much lower than at pH 12, indicating lower reaction rates and ozone effectiveness. The COD removal is around to 10%, even when the applied ozone charge is 2.4 mg O3/mg of initial COD.
0
10
20
30
40
50
60
70
0 5000 10000 15000 20000 25000
BO
D5 / C
QO
, %
CQOin (mg O2/L)
BOD5
46
Figure 3 Ozone treatment of OMW, at different pH (initial COD: 1000 mg/L)
Figure 4 - Effect of ozone treatment on the BOD5/COD ratio of OMW (Ozone stage conditions: initial COD: 1000 mg/L; pH: 5.4)
Impact of ozone treatment on BOD5/COD ratio
Figure 4 shows the BOD5/COD ratio for increasing levels of applied ozone charges. Interestingly, the OMW biodegradability significantly increases with moderate applied ozone loads, and markedly decreases thereafter, recovering somewhat for extremely high ozone charges.
To evaluate the possible role of phenolic compounds in this behavior, figure 5 presents the evolution of phenolic compounds with ozone treatment.
Figure 5 Effect of ozone treatment on phenolic compounds (Ozone stage conditions: initial COD: 1000 mg/L; pH: 5.4)
Figure 5 reveals a drastic decrease of phenolic compounds for moderate ozone applied charges and an unexpected recover for increasing ozone loads, which is under investigation.
Conclusions
OMW has an extremely high organic load and high content of phenolic compounds which anticipates difficulties in its treatment by biological means, particularly by anaerobic microorganisms that are more affected by the high phenols concentration.
The aerobic biodegradability depends on the concentration of the OMW that the microorganisms are exposed. For a COD concentration until close to 2000 mg/L the BOD5/CQO ratio is close to 50%, but decrease gradually until around 10%, when the COD was increased to 20000 mg/L. Considering the value of 0.45 as a reference for good biodegradability, the results suggest that an adequate dilution can allow an almost complete aerobic degradation.
The ozone treatment of OMW can enhance or decrease its aerobic biodegradability, depending on the amount of ozone applied. Moderated loads improve the biodegradability, while high loads can decrease the biodegradability.
References 1. Roig, A., Cayuela, M.L., Sánchez-Monedero, M.A.,
An overview on olive mill wastes and their valorisation methods. Waste Management 26 (***), 960 969.
2. ., Shannakb B., Al-Shannaga M., Al-Anbera Z. and Al-Hasanc M., Treatment of olive mill wastewater by combined advanced oxidation and biodegradation. Sep Purif Technol 70:141 146 (2009).
3. Panagiota P., Diamadopoulos E., Technologies for olive mill wastewater (OMW) treatment: a review J.Chem Technol. Biotechnol , 81:1475-1485-2006.
0
200
400
600
800
1000
1200
0 1 2 3 4
CO
D (m
g of
O2/
L)
Load of O3 applied (mg of O3/mg CODin)
pH 12
pH 5,4
0
0,2
0,4
0,6
0,8
1
1,2
0 1 2 3 4
BO
D5/
CO
D
Load of O3 applied (mg O3/mg CODin)
0
10
20
30
40
50
60
0 0,5 1 1,5 2
mg/
L (
as g
alli
c ac
id)
Load of O3 applied (mg of O3/mg CODin)
47
4. E. Bettazzi, M. Morelli, S. Caffaz, C. Caretti, E. Azzari, C. Lubello, Olive mill wastewater treatment: an experimental study, Water Science and Technology 54 (8) (2006) 17 25.
5. S. Crognale, A. D'Annibale, F. Federici, M. Fenice, D. Quaratino, D.M. Petruccioli, Olive oil mill wastewater valorisation by fungi, Journal of Chemical Technology and Biotechnology 81 (2006) 1547 1555
6. A. Robles, R. Lucas, G.A. Cienfuegos, A. Galvez,
wastewaters from the olive oil industry by strains of penicillium isolated from wastewater disposal ponds, Bioresource Technology 74 (2000) 217 221
7. Paixao SM, Mendonca E, Picado A and Anselmo AM, Acute toxicity evaluation of olive mill wastewaters: a comparative study of three aquatic organisms. Environ Toxicol 4:263 269 (1999).
8. Rouvalis A, Iliopoulou-Georgoudaki J and Lyberatos G, Application of two microbiotests for acute toxicity evaluation of olive mill wastewaters. Fresenius Environ Bull 13:458 464 (2004).
9. Tziotzios G., Michailakis S., Vayenas D.V., Aerobic biological treatment of olive mill wastewater by olive pulp bacteria, International Biodeterioration & Biodegradation 2007
10. Anastasiou C.C., Christou P., Michael A., Approaches to Olive mil wastewater treatment and disposal in Cyprus, Env Res Journal 5(2):49-58 (2011)
11. Chandra R., Rustgi R., Biobegradable polymers, Prog. Polym. Sci.vol 23 1273-1335, 1998.
12. Martín R., Navalon S., Alvaro M., Optimized water treatment by combining catalytic Fenton reaction using diamond supported gold and biological degradation diamond supported gold and biological degradation, Applied Catalysis B: Environmental Vol. 103, 1-2,246 252, 2011.
13. Ahmadi M, Vahabzadeh F., Bonakdarpour B., Mofarrah E., Mehranian M., Application of the central composite design and response surface methodology to the advanced treatment of olive oil
J. Hazard. Mater. 123 (2005) 187 195. 14. Benitez FJ, Beltran-Heredia J, Torregrosa J and
Acero JL, Treatment of olive mill wastewaters by ozonation, aerobic degradation and the combination of both treatments. J Chem Technol Biotechnol 74:639 646 (1999).
15. Standard methods for the examination of water and wastewater. 20 ed. Washington: APHA, 1998
16. Mcdonald, S.; Prenzler, P. D.; Antholovic, M.;
Robards, K. Phenolic content and antioxidant activity of olive extracts 2001 73-84
48
Electrochemical degradation of clofibric acid at different anode materials D. Santos1, M.J. Pacheco1, A. Gomes2, A. Lopes1, L. Ciríaco1
1UMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal 2CCMM, Department of Chemistry and Biochemistry, University of Lisbon, Lisboa, Portugal
Abstract The electrodegradation of a pharmaceutical compound, clofibric acid, was performed with 3 different anodes: a commercial boron-doped diamond (BDD) and two SnO2-Sb2Ox electrodes prepared in our laboratory, with platinization of the titanium substrate, followed by 4 or 16 alternate electrodepositions of antimony and tin, with further calcination, to form the oxides, and to obtain Ti/Pt/SnO2-Sb2Ox electrodes, denominated, respectively, Ti(4) and Ti(16). The structural, morphologic and chemical characterization of the electrodes was done by X-ray diffraction, scanning electron microscopy and spectroscopy of dispersion energy, respectively. The anodes were tested in the anodic oxidation of clofibric acid, in the presence of Na2SO4 aqueous solutions, at a current density of 10 mA cm-2, during 6 hours for BDD anode and 24 hours for the SnO2-Sb2Ox anodes. The degradation tests were followed by UV-Vis absorption spectrophotometry and chemical oxygen demand (COD) and total organic carbon (TOC) determinations. Among the prepared oxide materials, Ti(4) presented the best degradation rate of the organic compound, besides the lower energy consumption. However, when the three electrode materials are compared, the commercial BDD anode is the one that presents the best removals for COD, TOC and Abs, but it is also the most expensive material. Introduction Pharmaceutical compounds are being detected as pollutants in effluents from sewage treatment plants. Most of these compounds present low biodegradability and is important to develop alternative degradation methods like electrochemical oxidation. Recently, electrochemical oxidation has shown to be a good alternative process to eliminate pollutants. Several anode materials have been studied in the last years, like noble metals, metallic oxides, namely doped SnO2, and boron doped diamond (BDD) that have conduced to effective degradation/ mineralization of several pollutants [1-4]. The choice of the anode material is highly important, since it must possess stability in the experimental conditions of the electrodegradation process, even at high anodic current intensity, high potential for the oxygen evolution reaction, long lifetime and should not be too expensive. In this work the electrodegradation of a pharmaceutical compound, clofibric acid, was performed with 3 different anodes: a commercial BDD anode and two composite electrodes, Ti/Pt/SnO2-Sb2Ox(4) and Ti/Pt/SnO2-Sb2Ox(16), prepared in our laboratory [5].
Materials and Methods Preparation of the SnO2-Sb2Ox electrodes To prepare the Ti/Pt/SnO2-Sb2Ox electrode, the titanium substrate was first submitted to a pre-treatment [4]. After that, the electrodeposition of platinum was performed at 65 ºC, in H2PtCl6 acid solution, applying a current density of 250 mA cm-2 [6], and using two plates of platinum with 10 cm2 as anodes and, as cathode, the titanium plate, with 10 cm2 (both sides) geometric area, placed between the anodes. The electrodeposition of tin was performed, at 35 ºC, in an acid solution of SnCl2, applying a current density of 10 mA cm-2, and using two plates of platinum as anodes and the plate of platinized titanium as cathode, between them. The antimony electrodeposition was also performed at 35 ºC, in an acid solution of Sb2Cl3, applying a current density of 10 mA cm-2, and using an experimental set-up similar to that used in the electrodeposition of tin. Alternate electrodepositions of Sn and Sb were performed four times and sixteen times, each metal, depending on the anode in question. The titanium substrate with the electrodeposited metals was annealed at 550ºC, during 6 hours, to obtain the respective oxides. The prepared electrodes were characterized by the following techniques:
� X-Ray diffraction (XRD) � Scanning electron microscopy (SEM) � Energy dispersive spectroscopy (EDS)
Experimental conditions for the degradation assays Figure 1 presents the experimental set-up used in the degradation assays. The assays were run at 10 mA cm-2
applied current density. 200 mL of solution were used, containing clofibric acid with a concentration of 100 ppm and the supporting electrolyte, Na2SO4, 0,035 M. The following analyses were performed with the samples collected during the electrodegradation assays: UV-Vis absorption spectrophotometry; COD determinations; TOC determinations.
Figure 1 – Experimental set-up for the degradation assays. 1- Power supply; 2 - Anode – Ti/Pt/SnO2-Sb2Ox(4) (10 cm2), Ti/Pt/SnO2-Sb2Ox(16) (10 cm2) or BDD (10 cm2); 3 - Cathode – stainless steel (10 cm2); 4 - Magnetic stirrer; 5 – Stirring plate
49
Results and Discussion In Fig. 2, X-Ray diffractograms for the prepared anode materials allowed the identification predominantly of two phases: SnO2 and Sb2O4. The micrographies, presented in Fig. 3, show a similar aspect for both materials.
Figure 2. X-Ray diffractogram of the prepared materials.
a) b) Figure 3. Micrographies of (a)Ti/Pt/SnO2-Sb2Ox (4) and
(b) Ti/Pt/SnO2-Sb2Ox (16)
The micro-analysis of the electrodes’ surface by EDS shows similar compositions for both materials, with the following atomic percentages:
• Ti/Pt/SnO2-Sb2Ox (4) - 74% O; 9% Sn; 17% Sb. • Ti/Pt/SnO2-Sb2Ox (16)- 80% O; 6% Sn; 14% Sb.
The COD, TOC and absorbance (Abs) results for the samples collected during the anodic oxidation assays are presented in Fig. 4 and Table 1. Among the prepared oxide materials, Ti(4) presented the best degradation rate with lower energy consumption. However, the highest COD removal rate was obtained with the BDD anode. Conclusions Two different anodes of Ti/Pt/SnO2-Sb2Ox, with 4 and 16 layers of each metal deposited alternatively, were prepared successfully. In the XRD characterization two predominant phases were identified, SnO2 and Sb2O4. Electrodes from these materials and BDD have been used successfully in clofibric acid electrodegradation. After 6 h of treatment with oxides anodes, absorvance removal was appreciable, but COD and TOC removals were low. The best results were attained with BDD anode.
Figure 4. COD, TOC and Abs (228 nm) results for the samples collected during the clofibric acid degradation with the different anode materials, at 10 mA cm-2. Table 1. Results of the COD, TOC and Absorbance removals for the degradation assays of clofibric acid run at 10 mA cm-2.
Removal at 6 h / % Anode material COD TOC Abs (228 nm)
Ti/Pt/SnO2-Sb2Ox(4) 11 18 49
Ti/Pt/SnO2-Sb2Ox(16) 14 8 33
BDD 72 61 73
Acknowledgements The financial support of FCT is gratefully acknowledged: PTDC/CTM/64856/2006 and BI Grant of D. Santos. References 1. Kotz, R., Stucki, S., and Carcer, B., J. App.
Electrochem., 21, 14, 1991. 2. Cossu, R., Polcaro, A.M., Lavagnolo, M.C., Mascia,
M, Palmas, S., and Renoldi, F., Environ. Sci. Technol., 32, 3570, 1998.
3. Stucki, S., Kötz, R., Carcer, B., and Suter, W., J. App. Electrochem., 21, 99, 1991.
4. Electrochemistry for the Environment, Ed: Ch. Comninellis and G. Chen, Springer New York Dordrecht Heidelberg London, 2010.
5. Ciríaco, L., Santos, D., Pacheco, M. J., and Lopes, A., J Appl Electrochem, 41, 577, 2011.
6. Andrade, L.S., Rocha-Filho, R.C., Bocchi, N., and Biaggio, S.R., Quim. Nova, 27, 866, 2004.
50
A Perspective on key factors for successful transfer of technology I. G. Trindade 1, M. Pereira1,2, R. Miguel1,2, J. Lucas1,2 and M. Santos Silva1,2
1Unidade de Materiais Têxteis e Papeleiro, Rua Marquês D´Ávila e Bolama, 6201-001 Covilhã, Portugal 2Departamento de Ciência e Tecnologia Têxteis, Universidade da Beira Interior, Rua Marquês D´Ávila e Bolama, 6201-001
Covilhã, Portugal
Abstract In this article, a perspective on key factors for successful transfers of technology between academia and society is presented. The role of the government and local authorities, of academia transfer of technology offices and cultural barriers between industrials and academic are invoked and related research works are put in perspective. A short review in the field of smart textiles is presented, in terms of technical, product and business aspects. Important factors to attain successful transfers of technology from academia to industry in the particular field of Intelligent Textiles are pointed out, based on recent communications in International Conferences in the field. Introduction A landmark in transfer of technology, the Bayh-Dole act, adopted in USA in 1980, gave United States universities, small businesses and non-profit institutions, control of their inventions and rights to Intellectual Property ownership. Most European countries have adopted similar legislation to impulse transfer of knowledge from Universities and public funded Research Organizations to Society1. Since the Bayh-Dole legislation adoption, the expectation arose that Universities generate new processes, products and services transferable to society. Those transfers of knowledge to society are done through licensing of patents, direct transfers of technology to industry, creation of start-ups and spin-offs. An interesting conceptual model that addresses the role of the state in the transfer of knowledge and technology affairs is the triple helix model by Etkowitz e Leydesdorf 2, 3. In this model, specific goals are defined from the start, and are actively worked out with the interrelated participation between government, academia and industry. Regional clusters are examples of the application of the triple-helix model. Their success depends upon geographical location and local infrastructures, of synergies created by the cluster´s management and cluster´s members, the local human resources profiles and government and regional policies and incentives. Clusters facilitate and promote the transmission of knowledge and of learning through the circulation of collaborators among firms, through the cooperation between firms and institutions of R&D, and the consolidation of critical mass necessary to innovation, through nucleus of R&D, spin-offs and continuous interaction between enterprises and High Learning Institutions4. Several research works in the field pointed out the importance of the existent human resources profile (education and competences) for the efficacy and success of regional clusters. A study in European regional clusters
concluded that Ph.D. degrees in engineering and science enhance the efficacy of transfer of knowledge in Regional Clusters5; from Asia, similar research studies led to the conclusion of the necessity that the state and local political authorities create incentives to motivate youth to engage in High Learning degrees in science and engineering, as human resources are the main source to attract/initiate economically competitive high technology industries6. However, a continuous analysis of the results as a function of the regional applied politics and state incentives is fundamental to correct the applied measures and have academics and industrials reaching the specified goals7, other research works recommend.
Another consequence of the Bayh-Dole act adoption was the necessity that Universities integrate Transfer of Technology Offices (TTOs). The TTOs main role is to generate synergies for an active role of the university in profitable transfers of knowledge and technology, secure the intellectual property generated internally by research activities, and support legal agreements between researchers and industrials in collaborative developments. An econometric study based on data from 113 North-American universities and parametric variables number of patents disclosed, number of license agreements, profit with licenses, number of TTOs employees and legal expenses encountered significant correlations among those variables and other factors affecting academia industry transfer of technology (AITT)8. Incentives to TTOs staff, larger TTO teams with high experience, "Good" environment (local industries, clusters, regional policies, etc.) are factors positively correlated with large number of patent disclosures and high profits with license agreements. TTOs with own lawyers or stable agreements with lawyer´s offices have higher AITT and higher profits with license agreements despite the fact that legal expenses are higher. Cultural barriers between Industrials and Academia Researchers have a significant negative impact in AITT. For the last decades, Portuguese governments created strategic areas of R&D, mostly aligned with European Union (EU) strategy for economic growth and social development. Many technological regional clusters and financial incentives were created. Examples are the QREN program and International Cooperation between High Learning Institutions and between those and Industrials and entrepreneurs. Portugal has a long tradition in the textile industry, but with the globalization, the textile industry landscape dramatically changed. There are fewer players and the rate of textile exports has been steadily increasing. In the next section a short perspective of an emergent textile industry is presented.
51
Fig. 2. Smart textiles market shares by segment: (Top) US market share, from Chambers of Commerce, 200812; (Bottom) Worlwide market shares by segment, from InterTech Pira report, 201114.
Fig. 1. 1- Vital Jacket, from the company Biodevices S.A., and respective graphics of electrocardiogram the T-shirt monitors; 2- Electroluminescent wire (EL) dress, by Diana Eng at the Fairytale Fashion show, NYC, 2010; 3- Galaxy dress with light emitting diodes (LEDs), by Cute Circuit.
AITT in the field of intelligent textiles One important change that industries may suffer to stay competitive is to change from a strategy based in scale to that based in differentiation9. Smart Clothing or Intelligent Textiles is an emergent industry in High Learning societies, combining electronics and textile manufacturing. Smart textile products meet all criteria of high-added value technology allowing a transformation to a competitive high-tech industry, from resource-based towards knowledge-based, from quantity to quality10. Smart textiles are defined as clothes that interact with the user, by either monitoring or stimulus10. They generally integrate electronic sensors and actuators, electronic units that convert analog signals into digital streams and radio transceivers for reception/emission of data streams. Since 2000 that EU has been funding research and development in the field of smart clothing, in a total funding budget of nearly . Examples of EU funded projects in the field of smart textiles are; "Wealthy", from 01/09/2002 to 28/02/2005, "MyHeart", from 31/12/2003 to 31/05/2006, "Clevertex", from 1/10/2005 to 31/03/2008, "Proetex"Systex", from 30/04/2008 to 30/04/2011, 1/09/2008 to 31/08/2011, 2009 to 30/11/2012,"Psyche", from 1/01/2010 to 30/04/2013,"Veritas", from 1/01/2010 to 31/12/2013. According to the Textile Institute11, smart clothing is an interdisciplinary field that results from the intersection of
design research, physiology and textile technology, where design research comprehends several stages of product design: generation of ideas, design, prototype development, evaluation and design refinement, and production planning12. While mainly developed for health care future products, smart clothing manufacture can use different degrees of smart components integration, from high degree as tattoos and implants, to medium degree integration such as wearable, to low degree of integration such as handheld13. In addition, smart textiles can provide not only functionality but also expressiveness. In High Fashion the smart textiles have the purpose of personal expressiveness, in sportwear the functionality is important but some stylish is also present while in workwear the functionality is very specific and totally limits the personal expressiveness13. In Figure 1 are shown some examples of high-added value smart textile products: a t-shirt for cardiovascular monitoring in real-time anywhere, that in addition to the sensing shirt it integrates a personal digital portable unit for recording and data communication with either PCs or cell phones in the proximity; fashion dresses that integrate embedded electronic components such as electroluminescent wires
52
(EL) and light emitter diodes (LEDs) to produce glamour. Smart textile products have multiple applications, from health care and military to fashion and entertainment. Military and safety were the main applications of smart textiles, but currently other segments are in expansion. In Figure 2 are shown two graphs representing the smart textile market distribution by segment, for USA12 (British Chambers of Commerce, 2008) and Worlwide14 (InterTech Pira report, 2011). In USA, smart textiles for the entertainment segment have a considerable market share, but worldwide other growing market segments are architecture, transportation, sports and fitness. A question often put forward is what are the main challenges to manufacture smart textiles? Large and small companies debating these questions, point out the difficulty to combine Textile and Electronic Manufacture processes. There is a dilemma concerning where to put the interface on technical level in the supply chain between the electronic manufacturing service and the textile manufacturing service15. Another challenge concerns availability of human resources with competences to deal with interface textile / electronics manufacturing.
Conclusions Public policies have strong influence in the transfer of knowledge from Institutions of High Learning to Society. The government and local authorities can provide support with infrastructures, incentives and legislation to promote the involvement of academia in economic development. State policies play an important role in regional economic development based in transfer of knowledge from academia to industry. Public measures involve not only legislation but other measures such as the definition of strategic fields for R&D; engagement with academics and entrepreneurs to establish best resources, legislation and incentives. State and local actions may include the creation of programs and incentives to attract people to science and technology degrees, to promote innovation and entrepreneurship and cultural changes. TTOs staff and administration policies affect AITT. Cultural differences between scholars and researchers and industrials should be worked out to the benefit of all. Smart Clothing is a field that is strategic for EU and north-America countries. It has great potential for growing in market segments like Fashion and Entertainment, Sportswear, Medical, Transportation and Home/Architecture. It requires interdisciplinary teams (Design, Fashion, textile, electronic and communications engineering, Medical expertise, Sports expertise, etc.). The manufacture processes involved in smart textiles are critical and should be worked out from the beginning with industrial partners. Smart Textiles is a growing industrial sector with many segments that require the support of human resources with new competences and knowledge.
References 1. Siepmann, Thomas J., The Global Exportation of the
U.S. Bayhdole act, University of Dayton Law Review, vol. 30:2:209-243, 2004-2005.
2. Etkowitz, H., Leydesdorff, L.,The Triple Helix as a Model for Innovation Studies, Science & Public Policy, Vol. 25, No. 3:195-203, 1998.
3. Etkowitz, H., Leydesdorff, L., The dynamics of innovation: from National Systems and "Mode 2" to a Triple Helix of university industry government relations, Res. Policy 29: 109-123, 2000.
4. Keeble and Wilkinson, Collective learning and knowledge in the evolution of regional clusters of high technology SMEs in Europe, Regional Studies 33, no. 4:295-333, 1999.
5. Storey and Tether, Public policy measures to support new technology-based firms in the European Union, Res. Policy 26:1037-1057, 1998.
6. Lai and Yap, Technology Development in Malaysia and the Newly Industrializing Economies: A Comparative Analysis, Asian Pacific Development Journal, Vol.11, No. 2:53-80, 2004.
7. Hulsink, W., Suddle, K., Hessels, J., Science and technology-based regional entrepreneurship in the Netherlands: building support structures for business creation and growth entrepreneurship, published under the SCALES-initiative (SCientific AnaLysis of Entrepreneurship and SMEs), as part of the 'SMEs and Entrepreneurship program financed by the Netherlands Ministry of Economic Affairs, 2009.
8. Siegel, Donald S., Waldman, D., Link, A., Assessing the impact of organizational practices on the relative productivity of university technology transfer offices: an exploratory study, Research Policy 32: 27-48, 2003.
9. Porter, W. E., What is Strategy?, Harvard Business Review, Nov-Dec:61-78, 1996.
10. Langenhove, L. Van, Hertleer, Smart clothing: a new life, International Journal of Clothing Science and Technology, Vol. 16, Iss: 1/2, pp.63 72, 2004.
11. Source: Textile Institute, 2006. 12. 12. Suh, Carroll and Cassill, Critical Review on Smart
Clothing Product Development Journal of Textile and Apparel, Technology and Management , vol. 6 4:1-18, 2010.
13. Seymour, S., Fashionable Technology: The Intersection of Design, Fashion, Science, and Technology, Springer Wien New York, 2008.
12 14. Wilson, A., The Future of Smart Textiles, oral communication, Smart Fabrics Conference, London, April 2011.
13 15. Pieterson, L., Os, K., Abeelen, F., Luitjens, S., Zhou, G., Philips Sense and Simplicity: Conformal Lighting, oral communication at the Smart Fabrics Conference, London 2011.
53
Hakea sericea
“green” consumerism, desiring Plant material:
GPS coordinates: N 40º20.296’; W 07º27.491’; Altitude:
d’Ajuda
Extraction process:
Phytochemical screening:
Ciocalteu’
54
was made using Dragendorff’s
Evaluation of antioxidant activity: and β
In the case of β
RP-HPLC analysis of phenolics:
through a 0.22 μm pore size membrane filter before
and then filtered through a 0.22 μm pore size membrane
Determination of antimicrobial activity Test microorganisms and culture media:
Disc diffusion assays:
Determination of Minimum Inhibitory Concentration (MIC) by agar dilution method:
55
–
–
–
S. aureus B. cereus L. monocytogenes E. coli P. aeruginosa K. pneumoniae Candida tropicalis Candida albicans
Hakea sericea
Antioxidant activity measured by β
56
–
S. aureus B. cereus L. monocytogenes E. coli P. aeruginosa K. pneumoniae Candida tropicalis
Candida albicans
MRSA 10/08
MRSA 12/08
Jardim Botânico d’Ajuda
57
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)
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59
Estudo sobre a distribuição da velocidade do escoamento secundário de um fluido viscoelastico FENE-CR numa curva de secção quadrada
J. M. Malheiro 1, P. J. Oliveira 1, F. T. Pinho 2 1Dept. Eng. Electromecânica q UMTP, Faculdade de Engenharia, Universidade da Beira Interior, Covilhã, Portugal 2Dept.
Eng. Mecânica q CEFT, Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
Resumo Este trabalho consistiu em analisar os efeitos da elasticidade no escoamento de um fluído viscoelástico FENE-CR através de um canal curvo de secção transversal quadrada. Para isso foram feitas simulações para números de Reynolds até 1760 e para números de Weissenberg até 1, numa curva de 180� de secção quadrada. Verificou-se que a inércia comanda o escoamento na primeira metade do canal (dos 0� aos 90�) e que a elasticidade afecta o escoamento na segunda metade do canal (até aos 180�), verificando-se predominância dos efeitos inerciais para os valores do número de Reynolds mais elevados.
Introdução O escoamento num canal curvo é dominado por um escoamento secundário na direcção transversal. O escoamento secundário é caracterizado por um par de vórtices, simétricos e que ocupam a totalidade de secção transversal do canal. Consoante as condições de escoamento, o escoamento secundário pode alterar-se de um par de vórtices para dois pares ou mais. Sugiyama et al. [1] verificou, através da visualização do escoamento, que para uma secção transversal rectangular, o aparecimento de dois pares de vórtices adicionais no escoamento secundário depende da razão de curvatura. Helin et al.[2] investigaram a influência da elasticidade e outros parâmetros materiais na transição do escoamento secundário de um par para dois pares de vórtices, considerando um fluido viscoelástico PTT. Bara et al.[3] e Mees et al.[4] estudaram os efeitos inerciais no desenvolvimento de pares adicionais de vórtices no escoamento secundário, considerando um fluido newtoniano. Observaram que o aumento da inércia, numa curva de secção quadrada, leva ao desenvolvimento de escoamentos secundários com dois [3, 4] e três [4] pares de vórtices. O presente trabalho tem como objectivo investigar o desenvolvimento do escoamento secundário em termos da distribuição da velocidade, considerando efeitos inerciais e de elasticidade, para o modelo viscoelástico FENE-CR.
Equações de Governo O escoamento rege-se através das equações de conservação da massa e do momento, que são escritas, respectivamente:
0�� u (1)
. totpt
� ��� � �� �
�u u u� � � (2)
u - vector velocidade � - operador gradiente � - densidade do fluido t - tempo p - pressão
tot� - tensor das tensões O tensor das tensões é definido por:
tot s� �� � � (3) onde s� é a contribuição do solvente, que segue a equação constitutiva para fluidos newtonianos, com viscosidade s , e � é a contribuição das moléculas de polímero, que segue a equação constitutiva do modelo FENE-CR [5]:
�2 pf
� �
�
�� �� �� �� �
� � D (4)
�f � - função de extensibilidade definida por:
� � �2
3 3pL tr
fL�
��
��
� (5)
D - tensor velocidade de deformação: �1
2T� �D u u� �
�p - viscosidade de polímero � - tempo de relaxação L2 - parâmetro de extensibilidade Os parâmetros adimensionais relevantes para o estudo são: - Número de Dean (Dn):
ReDnR a
� (6)
- Número de Weissenberg (Wi): mWi U a�� �� � (7)
- Número de Reynolds (Re):
Re mU a��
� (8)
Um - velocidade média μ - viscosidade: p s� � � � - razão de deformação: mU a� � a - lado da secção transversal R - raio médio de curvatura: �1
1 22R R R� �R1 e R2 - raios interno e externo da curva, respectivamente
60
O escoamento é considerado como tridimensional, isotérmico, laminar, independente do tempo e o fluido é incompressível, com � constante.
Geometria, Condições Fronteira e Método Numérico A geometria é a mesma utilizada por Bara et al.[3], Mees et al.[4] e Helin et al.[2], e consiste em dois canais rectos, um à entrada e outro à saída, de dimensão Le= 20a; acoplados a um canal curvo de 180º, de raios interno e externo de dimensão R1= 14.6a e R2= 15.6a, respectivamente (Figura 1). A secção transversal é quadrada de lado a= 1, com razão de forma k= 1, correspondente a uma secção quadrada. O raio médio de curvatura é R= 15.1 e a razão de curvatura é Rc= R/a= 15.1. A posição das secções em que o perfil de velocidades é analisado será definido pelo angulo �, de 0� à entrada da curva, 90� a meio da curva e 180� à saída da curva.
Entrada
Saída
Parede interior
Parede exterior
Pare
de In
teri
or Parede Exterior
Figura 1 q Geometria do canal curvo de secção quadrada.
Como condições fronteira considerou-se: - não escorregamento nas paredes do canal; - escoamento completamente desenvolvido à entrada; - gradiente axial nulo para a velocidade e para a pressão à saída; - todo o domínio é considerado; As propriedades físicas e reológicas do fluido são consideradas constantes. O método de volumes-finitos foi utilizado para a resolução das equações de governo. O código de CFD utilizado [6] é baseado num sistema de coordenadas não-ortogonais e malha colocada, onde as variáveis são calculadas no centro de cada volume de controlo. As equações de governo são discretizadas por integração, e resultam num sistema linear de equações algébricas para as equações da massa, momento e constitutiva. O algoritmo assegura o acoplamento dos campos de pressão
e velocidade, através de um processo iterativo de correcção da pressão de forma que a continuidade seja verificada. Resultados e Discussão Neste trabalho, fez-se variar o número de Weissenberg (Wi) de 0.0 até 1.0 para diferentes números de Reynolds (Re�� Hk]T@�� Os resultados obtidos indicam que para Re�R`]� �� '�����)� ��� Wi não afecta o escoamento. No entanto, para Re=532 (Figura 2), Wi afecta o desenvolvimento do escoamento a partir dos 120� até ao final da curva. Aos 120�, à medida que Wi aumenta, a velocidade axial máxima decresce ligeiramente em magnitude e a sua localização move-se ligeiramente na direcção do centro do canal. Mais à frenteao longo do comprimento da curva, este comportamento torna-se mais pronunciado, e para Wi�0.6 verificam-se alterações na forma do perfil de velocidades. Esta crescente transferência de quantidade de movimento e mudança de forma do perfil de velocidade, com o aumento de Wi, são causadas pela formação de um par adicional de vórtices junto à parede externa do canal [3]. No caso Newtoniano, o aparecimento do segundo par de vórtices só acontece para valores superiores a Re�\`O� L3]. Ao aumentar a inércia para Re= 583 (Figura 3), o efeito de Wi aos 120� é superior do que no caso Re=532, na mesma localização. Aos 150�, apesar de a transferência de quantidade de movimento na direcção do centro do canal se tornar também mais intensa com o aumento de Wi, as diferenças entre os perfis de velocidade para os diferentes valores de Wi reduzem-se (comparado com os perfis de velocidade para Re=532 na mesma localização na curva) e a 180º os perfis de velocidade viscoelásticos tendem a sobreporem-se. Na Figura 4, onde os perfis de velocidade para Re=1760 são apresentados, pode ser observado que o ponto de velocidade máxima move-se na direcção do centro do canal mais rapidamente do que para valores de Re inferiores. No entanto a variação de Wi afecta o escoamento apenas aos 90�, empurrando ainda mais a região de maior quantidade de movimento para o centro do canal. Ao contrário dos outros casos, não se verifica quaisquer efeitos provocados por Wi após os 90�. Conclusões A transferência de quantidade de movimento na direcção do centro do canal, que está associado ao aparecimento do par adicional de vórtices no escoamento secundário, aumenta com a inércia e com a elasticidade, apenas em determinadas situações. De uma forma geral, a inércia controla o escoamento na primeira metade do canal (i.e. até aos 90�) e a elasticidade afecta significativamente o escoamento secundário na segunda metade da curva. Enquanto para Re= 532 os efeitos de Wi são observados até ao final da curva (180�), para Re= 583 a influência do aumento de Wi ocorre apenas até aos 150�. Para Re= 1760 a inércia controla o escoamento excepto na região dos 90�, onde o escoamento é também afectado pela elasticidade.
�
61
0 0.5 1Y-1
0
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U
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U
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U
DeNewtoniano0.10.20.30.40.50.60.70.80.91.0
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Figura 3 q����#������'��*���������\`O�����"�������������X������"�����������������"�*�'�����/�HFT���H\T����H`T��
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Figure 4 q����#������'��*���������Hk]T�����"�������������X������"������������������*����"�������>�����"�*�'�����/�^T���
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62
Referências H� ����&����� ���� +�&��%��� !��� ����E�=��� [��� ?H^`O@��
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Z�<�������������*%��F^��O`H-ROF�]� ���'������ �� ��� ���%�� ��!��� ����� }���?H^^`@�� �� Z�-
Z�<�������������*%��k^��H-RO��
Agradecimentos �� ������)� "���� �� $���*��� �� !�*������� "���#����*������ ���'��� ��� ����� ��� �����������+�(��]`O\k�FTHT��
63
Synthesis and characterization of electrically conductive textile/PEDOT samples
I. G. Trindade1, 2, C. Gaiolas1, 2, J. Lucas1,2, R. Miguel1, 2 and M. Santos Silva1,2
1. R&D Unit of Textile and Paper Materials, Universidade da Beira Interior, Rua Marquês D´Ávila e Bolama, 6201-001 Covilhã, Portugal
.2. Department of Textile Science and Technology, Rua Marquês D´Ávila e Bolama, 6201-001 Covilhã, Portugal
Abstract Textile fabrics of 100% polyester and 100% cotton were made electrically conductive by in situ polymerization. Rectangular stripes of textile samples, having the longer dimension parallel to the fabric weft direction were treated by low temperature Ar plasma and immersed into solutions of various concentrations of 3,4-ethylenedioxythiophene (EDOT) monomer and Fe(III)-toluene sulfonate (FTS) oxidant. Poly(vinyl) alcohol (PVA) and ethanol were used as binder and solvents. The electrical properties of textile samples polymerized with Poly(3,4-ethylenedioxythiophene) (PEDOT) were characterized by electrical measurements. The results showed that the samples treated by cold plasma prior to in situ polymerization exhibited many fold higher electrical conductivity than those that did not have plasma treatment. Furthermore, the polyester samples exhibited a surface resistance of the order of 1 kOhm/sq, one order of magnitude lower than the cotton samples. The electrical conduction of polyester/PEDOT samples exhibited an increase with the oxidant concentration in the EDOT:FTS synthesis solutions. The presented work is encouraging towards the use of polyester fabrics polymerized with PEDOT in wearable electronics.
Introduction The field of wearable sensors has gained much attention since the early ´s 2000. In particular, textile electrodes have been used for the monitoring of cardiac and muscle activity signals, for health care applications1 4. In previous works, textile electrodes made by means of embroidery with stitching machines and yarns of cotton stainless steel were realized and used for the monitoring of muscle activity5 and for the recording of the heart beat of a subject6. Textile electrodes prepared by in situ polymerization of polypirrol were previously developed and used for the monitoring of physiological signals7, 8. In the following of those works, electrically conductive textiles prepared by in situ polymerization of PEDOT are investigated.
The synthesis of doped polyacetylene with a conductivity of 105 S/m in the late 1970s9, leading to the award of the Nobel Prize in Chemistry in 200010 showed that plastics can be made electrically conductive as metals. The presence of conjugated double bonds along the backbone of the polymer allows the plastic to become electrically conductive in the presence of a suitable dopant. The alternating sequence of localised bonds with less strongly localised bonds, in a conjugated
polymer, yields electronic properties that can be tuned by the addition of dopants. Like semiconductors, the conjugated polymers have an energy bandgap separating the valence band of highest occupied molecular orbitals (HOMO) from the conduction band of lowest unoccupied molecular orbitals (LUMO)11. The splitting of the molecular orbital energy levels is a function of the number of the conjugated bonds in the polymer backbone as schematically represented in Fig. 1. In this simplified conceptual picture, conductive polymers are analogous to 1- D semiconductores, with electrical conductivity tuned by withdrawing electrons (p doping) as in oxidation, or by adding electrons (n doping) as by reduction.
Fig. 1: Schematic representation of the splitting of the valence and conduction energy levels with the increase of conjugated -states. Source: M. Hamedi, Linköping studies in science and technology, Dissertation No. 1224, Linköping 2008. . In the 1980´s Bayer introduced the PEDOT, a conjugated polymer that exhibits high chemical and physical stability, high electrical conductivity (500 Scm-1 to 1000 Scm-1) and can be made transparent. Later, that corporation intruced the liquid dispersion of Poly (3,4-ethylene dioxythiophene) poly (styrene sulfonate) (PEDOT:PSS), which can be applied to microelectronic substrates by spin coating and form thin films with thicknesses of less than 200nm 12-14. Textile fabrics can be made electrically conductive by in situ polymerization of solutions containing the monomer EDOT and the oxidant ferric p-toluenesulfonic acid diluted in solvents such as ethanol or butanol15. The electrical conductivity of the textile/PEDOT samples depends upon the concentration monomer oxidant dopant in the solution the fabrics are immersed into, the solvent, type of fabric among other variables. The amount of acid concentration in the
64
65
Fig. 3: I*-V experimental curves corresponding to polyester (PES)/PEDOT samples that either had (wPT in legend) or had not plasma treatment (NPT).
Fig. 4: Experimental curves of I* versus applied voltage for polyester/PEDOT samples prepared from various concentrations of EDOT= 1 M: FTS = X, with X= 0.2 M, 0.35 M and 0.5 M.
Table I: Summary of surface resistance results Fabrics R/sq (kOhm)
100% polyester 1.6 100% cotton 18
data corresponding to solution with concentration of EDOT:FTS = 1M:0.2M.
where I is the measured electrical current in Amperes and L and W are the geometric factors. The surface resistance, R/sq, was calculated by applying the Ohm ´s law,
*/
I
VsqR (3)
where V is the applied voltage.
Results and Discussion Fabric samples that prior to in situ polymerization were treated by Ar plasma exhibited considerably higher electrical conductivity than those not treated. The ratio in electrical conductivity of plasma treated and non plasma treated samples could be of the order of ten fold. This large difference is shown in Fig. 3, the corresponding data obtained with 100% polyester fabric samples that were immersed in a solution with a concentration of EDOT:FTS = 1 M: 0.7 M. The significant improvement in the electrical characteristics of textile fabric samples that were treated by cold plasma of Ar prior to polymerization is consistent with the state of the art described in the article review by Sparavigna17. The energetic ions of Ar enhance the grafting of the PEDOT around the textile fibers, being more effective in the polyester than in the cotton. The enhancement of the polymer grafting can be caused by functional radicals in the fibers that were generated by the plasma bombardment. This effect can be "bulk", that is across the depth of the fabric, or at the exposed surface mostly. The fact that the plasma treatment with Ar is more effective in polyester fibers than in cotton ones is not understood yet. Spectroscopic analysis may provide insight into differences obtained.
Electrical and weight measurements of fabric samples of cotton and polyester that were treated by Ar plasma indicate that while the former is the heaviest, the
latter has considerably higher gain of mass and higher electrical conductivity than the former (see Table I and Table II).
Table II: Summary of weight measurements Fabrics Initial m (g) Gain of m (g)*
100% polyester 0.138 0.080 100% cotton 0.180 0.045
* data correspond to solution with concentration of EDOT: FTS = 1 M: 0.2 M.
The electrical conductivity difference between cotton and polyester fabrics is consistent with the weight measurements that indicated that the polyester fibers retain considerably more polymer mass than the cotton fibers do. Polyester fabric samples treated by Ar plasma were immersed in EDOT FTS PVA solutions of various concentrations and the electrical conductivity was measured as a function of the concentration of EDOT: FTS. The results obtained showed increase of electrical conductivity with FTS concentration increase, as shown in Fig. 4.
66
Conclusions
References
for the discovery and development of electrically conductive polymers,
In Situ
67
Ionization of AO7 in different ionic media
M.J.R.G. Pires1, M.I.A. Ferra1, A. Marques1
Chemistry Department, University of Beira Interior, 6201-001 Covilhã
Abstract Acid orange 7 (AO7) is an azo dye widely used in
dyeing processes. Nevertheless acid-base properties of
this compound are not yet well known and values for its
acidity constant are scarce in the literature. The
thermodynamic acidity constant of AO7 was
determined, at 25 ºC, from spectrophotometric
measurements, using dilute aqueous solutions. The
influence of sodium chloride and sodium sulphate on
the acid-base equilibrium was also investigated. Debye-
Hückel equations were applied to the evaluation of the
ionic activity coefficients.
Introduction
Azo dyes are of great importance in industry, namely,
textile, paper, food, cosmetics and pharmaceutical
industries. Acid orange 7 (AO7) is an azo dye widely
used in dyeing processes [1] and so it is also present in
industrial effluents. Its molecular structure is shown in
Figure 1.
Figure 1 - Molecular structure of AO7
The azo dyes present, in general, aromatic groups bound
to the nitrogen atoms of the azo group. AO7 is a
sulphonated azo dye that has a hydroxyl group in the
ortho- position with respect to the azo bond, which
exhibits azo/hidrazone tautomerism [2]. This fact
affects its colour properties.
Acid-base equilibrium of this compound can be
represented by the scheme shown in Figure 2.
Figure 2 Chemical species in an aqueous AO7 solution
Acid-base properties of the acid orange 7 dye are not
yet well known and values for its acidity constant are
scarce in the literature. Only one value for its acidity
constant was found in the literature (pKa= 11.4) [1].
The aim of this work is a study on the ionization of
AO7 that includes the determination of the
thermodynamic acidity constant at 25 ºC, from
spectrophotometric measurements [3], using the Debye-
Hückel equation, taking into consideration the Bates-
Guggenheim convention, for the calculation of the
activity coefficients [4], in dilute aqueous solutions. The
influence of sodium chloride and sodium sulphate on
the acid-base equilibrium was also investigated.
Materials and Methods
From a stock solution of AO7 (orange II) 4-(2-
hydroxy-1-naphtilazo)benzene-sulfonic acid, sodium
salt (C16H11N2O4SNa), purchased from Sigma-Aldrich,
85 %, dilute solutions with molalities around 10-5 mol
kg-1 were prepared in order to avoid the formation of
aggregates and to apply the Lambert-Beer law. Sodium
hydroxide solutions, prepared from Titrisol ampoules,
Merck, were used to increase the pH of the dye
solutions. Sodium chloride from Merck, 99,5 %, and
sodium sulfhate from Sigma-Aldrich, 99 %, were dried,
at 110 ºC, over night and kept in a dessicator. All
solutions were prepared with purified water, with a
resistivity of 18 M cm, obtained by a Milli-Q185 Plus,
Millipore apparatus .
UV-visible spectra were run in a He ios
spectrophotometer equipped with thermostatized quartz
cells. The temperature was controlled by means of a
thermostat, Grant LTD 20, and a digital thermometer
Hart Scientific 1502.
Results and Discussion
Spectra of aqueous AO7 solutions, at 25 ºC, are
presented in Figure 3 at different pH values: 6.48, 10.66
and 12.12.
Figure 3 - Spectra of azo dye AO7 4.0x10-5 mol kg-1 at
different pH values.
0
0,2
0,4
0,6
0,8
1
1,2
280 330 380 430 480 530 580
Ab
so
rba
nc
e
wavelength/nm
pH 6,48
pH 10,66
pH 12,12
68
1/2.
±0.008
pKm
I
69
70
Nanocrystalline TiO2 films prepared by sputtering for Rhodamine 6G photodegradation: catalytic efficiency, photo stability and reusability studies
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Materials and Methods !������� ��>���� %��� #����� <���� ��"����� �� �����"������� �&� ���*�'�� �$� �������� �"������� #�� ��>&���� "������ "�������� #� T�R� ��� ?����� \T{� #� %�� ���"�������@� ��� �� *���� ����� �&����� !%�� �>"���������������� ���������� %�� ��"����� "�*���� ���� %��*%���*���E���� ?���*������ ��"%���*��� ���� "�*���"�"�����@� �&� �-��&� ��##��*���� #����-�������� �*����������*�����*��*"������*�#�*����*��*"�������~-'����"�*��*"&�%�'�������"��'����&���"����LHFM������%��"%���������� �>"�������� <���� *���*��� ������ ��F\T� �V� ��#��������� "%���*�� LHRM�� !%�� �����������*�� ����� <��� �� R\T� |� +��'��� ������-"�����������*��&-'�"��� ���"�� %�� ��� ���������� �����&� ������RT-R`{����%������'��������������RT-RO{����%��'������������� #� %�� ���*�������*� �"�*����� !%�� *���&�*�"%��������������&��<����"��#�����������!��F�#�����<�%� �����*���������*������ ?^�k\�*�F@� ���Hk\��V�#�FT� ""�� �]}� �X����� ������� ����� � ����������� %��������� <���� ������� ��� ���=����� #�� H� %� � ������� %������"��� �X����������� ������� ����������� %�� �������<�������"������������������'������������&�����&��~-'����"�*��*"&�� �� �~-'��� �"�*�"%����� ��*� ~\]T�<��� ����� #�� �������� %�� ����"��� #� %�� �]}�������� ���� %�� ���� #� ��*���E���� <��� ����'��� �������� #� *%����� ��� ������&� �� ���>� #� %�� �&��� !%����*���E���� "%*���&�*� �##�*���*&� ?{@� %��� �����*��*��������/��
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74
A TRANSFERÊNCIA DE CONHECIMENTO E TECNOLOGIA NA ÚLTIMA DÉCADA: BREVE ANÁLISE DE MODELOS E RESULTADOS
Abstract
Introdução
Posição da Europa
75
76
Gráfico 2
Gráfico 3
77
Modelos de Transferência de conhecimento e Tecnologia
start-up
Figura 1 Figura 2
78
Considerações Finais
79
References
80
Web Referências:
81
Perovskite thin film electrodes for environmental applications produced by RF-Magnetron Sputtering
Abstract
Introduction
Materials and Methods
82
sample without adding any erroneous tilt information to
the data. The surface morphology of the films was
characterized by the root mean square roughness (Rrms)
wich was calculated by Topometrix software.
The oxides electrochemical behaviour was studied by
means of open circuit potential measurements and cyclic voltammetry, in 1 mol L 1 KOH solutions. Solutions were
prepared from AnalaR reagents with Millipore Milli-Q
water and degassed with nitrogen, 99.999% purity gas
supplied by Air Liquide. The electrochemical experiments
were performed in a two-compartment three-electrode
glass cell at room temperature. The counter electrode was
a graphite rod and, as reference, an Hg/HgO (0.099V vs.
SHE) was used. Voltammetric studies were carried out
using a low noise operational amplifier potentiostat
incorporated with positive feedback IR compensation,
programmed by a Bank VSG 83 waveform generator and
a Kipp & Zonen Pró-1 recorder and the chronopotentiometric studies with a Voltalab 32
Radiometer apparatus connected to an IMT 102 interface,
controlled by a personal computer through the
VoltaMaster 2 software.
Preliminary studies of photodegradation and
photolectrodegradation were conducted using a 250 mL
quartz photoreactor. The radiation source used was a
Spectroline series Model ENF-280C/FE (230 V, 50 Hz,
0.17 A). In the photoelectrodegradation experiments the
anode was Ca0.8Ho0.2MnO3 electrode and the cathode a
stainless steel foil, both electrodes being 1 cm2 in area and having a 1 cm gap between them. All anodic oxidation
assays were performed under galvanostatic conditions
with imposed current densities of 5 mA cm-2. The
processed solution volume was 100 mL with a
concentration of 100 ppm for IBU. Sodium sulfate
aqueous solutions (5 g L-1) were used as the supporting
electrolyte in all experiments. Assays were run for 24 h,
and data points were collected at 2 h intervals during the
first 8 h with a final one collected at 24 h. The
degradation of the ibuprofen was followed by UV Visible
absorption spectrophotometry with absorbance
measurements between 200 and 800 nm, using a UNICAM Hekios-a UV/VIS spectrophotometer.
Chemical Oxygen Demand (COD) determinations were
made following the titrimetric method, according to
standard methods [6]. Electrodegradation assays were also
monitored by measurements of Total Organic Carbon
(TOC), performed in a Shimadzu TOC-VCPH/CPN
apparatus.
Results and Discussion
The structural characterization revealed that the as-
sputtered manganite films were amorphous. To allow the
crystalline growth the electrodes were annealed at 800 ºC
in tubular furnace for 6 h in air. The XRD data for the
annealed manganites films are presented in Figure 1.The
XRD results revealed the formation of perovskite-type
phase for all the samples and the diffractograms are
characteristic of the orthorhombic symmetry, space group
Pnma.
20 30 40 50 60 70 80 90
Ca0.6
Ho0.4
MnO3
Ca0.8
Ho0.2
MnO3
CaMnO3
Inte
nsi
ty /
a.u
.
2 /
Figure 1. XRD patterns of the annealed manganite films deposited in ITO substrate (* - corresponds to ITO substrate).
The surface morphologies of the electrodes were studied
with AFM technique. Figure 2 shows the obtained AFM
images (two- and three-dimensional images) for all films
All the films exhibit a rough surface texture and consist of
particles fused together at the interparticle contact, building up high mountains and deep valleys.. The
analysis of AFM images show a slight increase in surface
roughness with the increase in Ho content.
Figure 2. AFM images (two- and three-dimensional images) of the annealed manganite films.
The open circuit potential of the Ca HoxMnO3 (x = 0,
0.2 and 0.4) oxide electrodes was measured in KOH 1
mol L 1. An average value of 0.041±0.005 V vs Hg/HgO
has been obtained. No meaningful changes were observed
by the presence of Ho-ions in the oxide. The value
approaches the thermodynamic value calculated for the
Mn4+/Mn3+ solid-state redox couple, 0.089V vs. Hg/HgO
[7]. This result indicates that the Mn4+/Mn3+ redox couple
83
Figure 3
Figure 4.
Table 1.
x Electrode type Rf
0
0
0.2
0.4
84
Figure 5.
Table 2 -
Conclusions
References
Acknowledgements
85
O efeito conhecimento nas tramas da próxima geração têxtil
Fernando Merino Intelligence CITEVE
O efeito conhecimento
As empresas estão confrontadas com grandes desafios
de inovação tecnológica versus inovação não-
tecnológica que condicionam as suas estratégias,
procurando inovar nas relações com fornecedores, na
cultura empresarial, na valorização dos recursos
humanos e no desenvolvimento do produto e da
tecnologia. A actual geração assiste a um fenómeno
de massas em que o consumidor é cada vez mais o
centro das atenções e passou a ser o foco da estratégia
competitiva das organizações.
A gestão do conhecimento estratégico, para o negócio
das organizações, coloca o consumidor como actor
central do cenário de novas tendências e de novos
argumentos de valor das tecnologias, para novos
negócios e novos mercados, que também passa pelas
estratégias de desempenho, de marcas e de
comunicação.
Tendências da próxima geração têxtil
Em 1969 o criador de moda Paco Rabanne
questionava-se desta forma: “O que será o vestuário
do futuro? Talvez possa ser utilizado como spray e a
mulher possa vestir-se com um aerossol colorido
aderente ao corpo, ou em arcos luminosos que
mudam de cor com a luz do sol ou até com as suas
emoções (…) o vestuário pode vir a alternar efeitos
de transparência com efeitos estéticos, reflectindo
estados de espírito e de atitude desprovidos de todo o
tipo de restrições, criando novas abordagens (…)
livres, verdadeiramente livres”. Já em 1935,
Raymond Loewy, o pai do design industrial, afirmava
que “As mais relevantes inovações no vestuário do
futuro estarão nos tecidos. Temos que assumir que
novos tipos de tecidos vão ser desenvolvidos e vão
influenciar consideravelmente o design do vestuário.
Esses tecidos poderão ser constituídos por células
microscópicas, de fibras retrácteis e expansíveis.
Quando afectados por alterações atmosféricas essas
células abrem ou fecham para regular a penetração
de ar. Por outras palavras, os tecidos vão funcionar
como ar condicionado. As costuras poderão vir a ser
substituídas por processos de moldagem ou de
cimentação”. Na história da moda, Paco Rabanne
ficou famoso pelas propostas futuristas da década de
1960 e foi pioneiro a combinar os têxteis com
materiais como o plástico e metais, razão pela qual
Coco Chanel apelidava-o de “metalúrgico”. Agora,
com os avanços da tecnologia, percebemos que as
visões fabulosas de Rabanne e Loewy com mais de
40 anos já podem ser materializadas.
Essas duas visões começam a estar presentes nos
desfiles de vestuário de ateliê, nas passerelles, mas
também estão cada vez mais presentes no vestuário
mais massificado que se encontra nas lojas, porque a
ciência que está a sair dos centros de investigação e
que já desfila nas passerelles, em instantes pode
chegar às lojas. A ciência está a responder com novas
soluções, como resposta aos novos desafios de
inovação e desenvolvimento, em design, em novos
materiais que respondam de forma inteligente a
influências externas como a mudança de temperatura,
humidade, químicos e bactérias, luz e radiação, fogo e
descargas eléctricas, que vão desde o vestuário de
86
moda ao vestuário multifuncional para protecção e
desporto.
Actualmente estão em curso outros processos de
inovação em materiais que vão revolucionar o
vestuário, mas talvez não seja necessário esperar
décadas para que se tornem inovações acessíveis.
Hoje, a transferência da tecnologia da parte de quem a
inventa para quem a utiliza é muito mais rápida, e
assiste-se também a uma maior partilha de áreas de
competência. Identificamos assim macrotendências
na investigação que, de um modo simples, podem ser
ilustradas desta forma:
Tendência 1
Tendência 2
Performance
Protecção
Conforto
Função
Glamour
Gadget
Tendência 3
Tendência 4
Nano
Inteligente
Leve
Solução
Biónica
Natureza
Tendência 1
A ciência está a responder com produtos que abrem
novas possibilidades ao design de soluções
inteligentes com materiais de elevada performance,
com preocupações ambientais e de segurança, a par
do conforto. O conceito de vestuário, por exemplo,
acompanha conceitos da arquitectura e por isso
partilha preocupações semelhantes. A protecção UV e
a termo-regulação são exemplos de funções
concebidas na engenharia do vestuário e na
arquitectura de edifícios, segundo pressupostos
semelhantes para efeitos práticos comuns.
Tendência 2
Estão a aparecer novas propostas que permitem
também novas abordagens à forma como nos
vestimos, isto porque, o vestuário deixou de ser
apenas uma questão de moda, e passou também a ser
uma questão de tecnologia. Já não se trata apenas de
conjugar cores, mas também de conjugar
funcionalidades. A revolução com origem na
miniaturização das tecnologias electrónicas criou
diversas oportunidades, tais como a incorporação, ou
quase fusão, da tecnologia mp3 com o vestuário. Mas
começam a aparecer outras possibilidades para além
do som, como a luz e a imagem.
Tendência 3
Produtos que recorrem aos nano e micromateriais
para novos conceitos de funcionalização de vestuário,
como a sensorização e monitorização dos sinais
vitais, mas também o vestuário mais leve e mais
inteligente. A miniaturização da electrónica
introduziu também avanços significativos nas
possibilidades de carregar tecnologia que mede o
estado de saúde de uma pessoa. Desde conhecer o
ritmo cardíaco, a tensão arterial e a temperatura do
corpo, entre outras. Mas a miniaturização dos
materiais à escala nano tornou possível produzir
têxteis com fibras à base de algas marinhas
dermoprotectoras e antimicrobianas com
nanopartículas de prata, mas também com
microcápsulas de materiais termo-reguladores.
Tendência 4
Por último, uma referência à biónica como uma nova
tendência que encontra em estruturas orgânicas,
presentes na natureza, novas soluções e novas formas
de inovação. A biónica é o estudo dos sistemas
biológicos e a descoberta de processos, técnicas e
novos princípios aplicáveis a qualquer tecnologia.
Este modelo é já uma realidade em várias aplicações,
como na aeronáutica, medicina, robótica ou
arquitectura, e é cada vez mais emergente também nas
tecnologias têxtil e de vestuário. O Corbeau Marin
(corvo-marinho), que inspirou o Comandante
Jacques-Yves Cousteau na criação do primeiro fato
87
de mergulho, é um exemplo emblemático de alta
tecnologia biónica.
Perspectiva afectiva do consumo
Com o crescimento de importância das tecnologias de
informação e da web 2.0, criou-se uma maior
proximidade das marcas, ganhou força o marketing de
relacionamentos, o marketing de proximidade e o
marketing viral. As marcas querem interagir com os
seus clientes (consumidores), mas as marcas têm
também a sua própria identidade. Assiste-se ao
fenómenos de marcas que pagam para não serem
vistas em reality shows1.
A moda é cada vez mais um contacto com a
tecnologia e não trata apenas de conjugar cores, mas
também de conjugar funcionalidades e por isso a
engenharia está a debruçar-se sobre a investigação
dos valores emocionais dos produtos, porque comprar
vestuário pode ser uma necessidade, mas também um
momento de felicidade.
A par da procura crescente de produtos de maior
qualidade, com melhor performance, melhor
funcionalidade e mais disponíveis em ciclos de
colecção e de avanços de colecção cada vez mais
frequentes, também as super tendências como o
hedonismo, espiritualidade e individualidade são um
desafio crucial para as marcas. Uma questão
subjacente a este aspecto é a de perceber se as novas
preocupações, dos novos consumidores, com novos
estilos de vida, são mais valorizadas e melhor
percebidas quando se encontram materializadas de
forma objectiva na comunicação associada, ou não, a
uma marca. Por isso a atitude do consumidor face a
padrões de comunicação sobre atributos de
responsabilidade social, mas também de qualidade e
1 A marca Abercrombie & Fitch paga a Mike “The Situation” da série Jersey Shore da MTV para não usar as suas roupas.
de performance, é uma das áreas de interesse para
perceber como se constrói a tomada de decisão de
compra, com base em informação explícita, como
etiquetas e símbolos.
A relação com o consumidor nos tempos actuais
(crise) é também uma relação muito emocional e é
necessário perceber a psicologia do consumidor [2]. É
fundamental segmentar o consumidor, não só da
forma tradicional, através de dados demográficos e de
estilos de vida, mas sim com dados psicológicos,
tendo em conta as reacções emocionais. As empresas
devem procurar compreender as mudanças nas
necessidades dos consumidores e ajustar as
estratégias e tácticas de comunicação, oferecendo
produtos que respondem à procura.
O vestuário tem um papel de destaque nas prioridades
de consumo, mas na hora de definir o comportamento
dos consumidores, os elementos tradicionais da
segmentação, como a idade e o status social, perdem
peso. A segmentação é cada vez mais definida a partir
de “conceitos”.
As marcas fincam através da sua comunicação,
comportamentos que plasmam na sua oferta, criando
“estilos de vida”, relacionando a comunicação da
marca com o comportamento, seja ele espírito de
aventura, dinamismo, agressividade, sensualidade [1].
Não é a idade que define qual a mulher que usa
Armani e qual a mulher que usa Versace. Ambas
podem ter 25 ou 50 anos. Armani transmite
dinamismo, modernidade e ao mesmo tempo bom
senso. Versace é mais tradicional, atrevida e
ostentativa.
A estética dos nossos tempos é ditada pela imagem
jovem, corpo delgado e pele bem cuidada. Há um
fenómeno que caracteriza a evolução da sociedade
nos últimos 30 anos e que a marcará no futuro: trata-
88
se do desejo de prolongar indefinidamente o modo de
vida e o aspecto juvenil. Nos anos 50 e 60 os “filhos
vestiam como os pais cinquentões” especialmente a
partir do momento em que formavam família (perto
dos 25 anos). Actualmente são “as mães a vestirem-se
como as filhas”. Para conseguir interpretar a
sociedade, antes de compreender as suas
necessidades, é fundamental interpretar os seus
sonhos [1].
Conclusão
A gestão do conhecimento estratégico para o negócio
das organizações, coloca o consumidor como actor
central do cenário de novas tendências e de novos
argumentos de valor das tecnologias, para novos
negócios e novos mercados, que também passa pelas
estratégias de desempenho, de marcas e de
comunicação.
O vestuário tem um papel de destaque nas prioridades
de consumo, mas na hora de definir o comportamento
dos consumidores, os elementos tradicionais da
segmentação, como a idade e o status social, perdem
peso. A segmentação é cada vez mais definida a partir
de “conceitos”.
A relação com o consumidor em tempos de crise é
também uma relação muito emocional e é necessário
perceber a psicologia do consumidor. Dessa forma, as
empresas devem procurar compreender as mudanças
nas necessidades dos consumidores e ajustar as
estratégias e tácticas de comunicação.
Referências
1. Agis, D., Bessa, D., Gouveia. J., Vaz, P.,
Vestindo o Futuro (2010).
2. Quelch, J., Jocz, K., Harvard Business Review,
April 2009.
89
A Intervenção do Design em Causas Humanitárias como o Controlo da Malária
C. Pinheiro1, M.J. Geraldes 1 ,R. Gomes2
1Universidade da Beira Interior
Abstract
Doenças transmissíveis por insectos atingem milhões de pessoas em todo o mundo. Calcula-se que ocorram anualmente 300 a 500 milhões de infecções palúdicas, sendo mais de 75% das vítimas crianças africanas com idade inferior a 5 anos. Perante estes números impressionantes, sentiu-se necessidade de proteger os que mais sofrem com esta terrível e mortífera doença, as crianças, através de um contributo na optimização da sua qualidade de vida. O presente trabalho funde-se no Design e Concepção de vestuário funcional para bebés, com propriedades de repelência ao Insecto da Malária, nomeadamente um babygrow com características que o inserem no domínio dos produtos têxteis funcionais, que repelem e matam não só o insecto da malária, como também outros insectos propagadores de outras doenças. O babygrow em questão foi realizado numa estrutura de malha Jersey, em Bambu, devido às propriedades ecológicas e anti-bacterianas. No seu acabamento foi utilizado o princípio activo IR3535 em nanopartículas.
Introdução
Doenças transmissíveis por insectos causam a morte de cerca de 700 milhões de habitantes por ano, especialmente em países tropicais e subtropicais, com maior incidência sobre os mais desfavorecidos (WHO: 2009: 1).
A malária, também conhecida como paludismo, febre palustre, impaludismo, maleita ou sezão é uma doença parasitária causada por protozoários1 do género Plasmodium, transmitida por mosquitos fêmea do género Anopheles (Neves et al,2005).
A infecção é transmitida indirectamente entre seres humanos, através da picada de mosquitos do género Anopheles, mas pode ainda ser transmitida através da placenta, transfusão de sangue e ainda partilha de agulhas ou seringas infectadas com plasmódios (Ferraz, 2002:8). Existem 156 espécies do Género Plasmodium que transmitem a doença a vertebrados, mas apenas 4 espécies são causadoras de malária no homem: P.falciparum, P. ovale, P. vivax e P. malariae, sendo P. falciparum o tipo mais mortífero da infecção e que origina as formas mais severas da doença (Rodrigues, 2007: 1). A espécie mais patogénica, o P. falciparum, é predominante na África sub- Sahariana e em algumas áreas do Sudeste Asiático e Oceânia. A segunda espécie mais comum, o P. vivax,
1 Os Protozoários são microrganismos unicelulares que vivem
sobretudo na água ou em líquidos aquosos.
raramente fatal, é frequente na Ásia, em zonas da América e no Norte de África (Ferreira, 2008: 4). A malária continua a ser a doença infecciosa humana mais devastadora e ameaçadora para a saúde pública e para o desenvolvimento económico das regiões tropicais e subtropicais do mundo, tendo vindo a ser apontada, como uma das principais causas de morte no mundo, estimando-se que, aproximadamente 40% da população mundial viva em áreas onde a doença é transmitida, atingindo 350 a 500 milhões de pessoas e causando a morte de mais de um milhão de pessoas anualmente (Ministério da Saúde, 2005: 9). Calcula-se que uma pessoa morra a cada 30 segundos por complicações relacionadas a picadas de insectos e que uma em cada 17 pessoas morrerá de alguma dessas doenças. Representa, ainda, risco elevado para viajantes e emigrantes, em áreas não-endémicas (WHO,2008:6).
Segundo o Instituto de higiene e Medicina tropical (IHMT), a malária é um grande fardo para a economia nacional de muitos países. A maioria dos economistas acredita que a malária é responsável por uma
alguns países. Uma vez que a doença ataca predominantemente em países menos desenvolvidos, isto leva a um ciclo vicioso de doenças e pobreza (IHMT,2007).
Dados sobre o relatório da OMS no final de 2004, mostram que existem 107 países que detêm áreas de risco de transmissão de malária e que cerca de 3,2 milhões de pessoas corre o risco de contrair a doença (Cunico et.al, 2008:49).
Noventa por cento da incidência mundial concentra-se na África e dois terços dos casos restantes ocorrem no Brasil, índia e Sri Lanka (Freitas, et al. 2007:2285). Nas áreas endémicas, o risco de malária grave ou fatal é maior em crianças com idade inferior a 5 anos, mulheres grávidas, e pessoas não imunes que viajam para áreas onde ocorra transmissão, segundo as estatísticas da Unicef para 2005 (WHO and UNICEF, 2005: 2). Em certas regiões africanas, chegam a morrer quase três mil crianças por dia em decorrência da malária (Camargo, 2003:26).
No Brasil, mais de 60% do território é favorável á transmissão da malária. Cerca de 95% dos casos no país ocorrem na Amazónia Legal, onde são registados perto de 500 mil novos casos por ano (Freitas, 2007: 2285). Em Portugal, alienou-se um maior conhecimento desta doença a partir da primeira metade do século XX, devido sobretudo aos estudos desenvolvidos por Francisco Cambournac (Cambournac, 1994: 215-22).
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Conforme ressalta Lepez Autuãno, a malária é um problema global, mas com características locais, por isso é extremamente importante conseguir-se actualmente um controlo efectivo nas populações (em minoria), onde os insectos atacam fora das casas, como é o caso da Tanzânia. Estudos efectuados sobre a situação da doença na Tanzânia verificaram que o padrão de comportamento de alimentação dos mosquitos se alterou neste país. Segundo Russell (2011:1), os mosquitos começaram a alimentar-se fora das habitações, devido á elevada utilização de redes mosquiteiras tratadas com insecticidas. Isto veio alterar drasticamente a vida das populações de vectores Africanos, levando a um controlo severamente difícil, porque as medidas preventivas usuais (redes insecticidas e pulverização com insecticidas) estão a deixar de fazer efeito, pois estas apenas podem proteger o indivíduo dentro das habitações, e à noite. Assim passa a ter importância abranger não só regiões onde já existe um controlo efectivo dos insectos, mas principalmente em regiões onde não existe, como é o caso da Tanzânia.
Apesar dos esforços desenvolvidos nas últimas décadas para eliminar a doença, através de medidas de controlo (gestão ambiental, insecticidas, mosquiteiros) ou de tratamento com antimaláricos, a malária continua a ser umas das doenças mais letais e com maior disseminação nos trópicos. Este é um grave problema de saúde pública que está a aumentar em diversas partes do mundo, sendo por isso importante na época de hoje, a da modernização da Indústria Têxtil, garantir a nossa segurança e a segurança contra riscos futuros, através do desenvolvimentos de têxteis de protecção no domínio de têxteis inteligentes/funcionais.
Metodologia
Este trabalho desenvolveu-se em várias fases, algumas das quais decorreram em simultâneo. As referidas fases foram:
1. Selecção dos materiais Têxteis;
2. Selecção da estrutura têxtil mais apropriada;
3. Pesquisa de mercado ao nível do design dos babygrows;
4. Selecção de produtos de repelência anti-mosquito;
5. Aplicação do produto repelente seleccionado;
6. Execução de um protótipo.
Duis A fibra têxtil seleccionada para a confecção do babygrow foi a fibra de bambu, dadas as características intrínsecas da mesma, conducente ao conforto do seu utilizador e dado a ser uma fibra anti-bacteriana e ambientalmente correcta.
Relativamente à estrutura têxtil a utilizar, escolheu-se a estrutura de malha, mais precisamente a estrutura Jersey, dadas as propriedades de elasticidade e conformabilidade
típicas das malhas, as quais são essenciais ao público-alvo deste trabalho, isto é, os bebés.
O repelente escolhido para a impregnação da tecnologia anti-insecto, foi o IR3535, devido a possuir um bom perfil de segurança em grávidas, crianças e bebés. O IR3535 é um bio pesticida sintético, que já está disponível na Europa há mais de 20 anos. É eficaz contra o Anopheles e o Aedes por um período de quatro a seis horas, com concentração.
Fig. 1.1 - A) Dispersão aquosa
As nanopartículas utilizadas para a impregnação da dispersão na malha de bambu, foram as de sílica
representadas na figura 1.1, devido a estas estarem revestidas por polímeros capazes de reconhecer e libertar o repelente IR3535 mais facilmente.
O passo seguinte foi impregnar o tecido com a dispersão no Foulard. Inseriu-se a dispersão aquosa na Tina de impregnação, localizada á frente do Foulard, e passou-se o tecido pelos cilindros revestidos de borracha de modo a este ficar totalmente impregnado.
Fig. 1.2 Frente e trás do Foulard utilizado para a impregnação da malha
Por último, inseriu-se a malha em bambu numa máquina de termofixação/secagem com o nome de Rámula a 120º durante 6 minutos. Normalmente o tempo utilizado é de 5 minutos, mas como a malha de bambu estava dobrada, levou mais um minuto que o normal. A figura abaixo mostra a maquina termofixadora Rámula, e o tecido preparado para entrar na mesma.
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Fig. 1.3 Rámula utilizada para a termofixação da malha impregnada com dispersão repelente de insecto
A execução do protótipo foi realizada após a selecção do design mais adequado ao mesmo, baseada na pesquisa de mercado efectuada.
Após a escolha do material, da estrutura de malha a utilizar e tecnologia procedeu-se á realização de diversos esboços em duas dimensões, para de seguida ser feita a triagem, figura 4.2. Esta fase permitiu o transporte de ideias para o papel no sentido de procurar soluções. Os babygrows além da pesquisa de mercado efectuada, tiveram como inspirações motivos animalescos, nomeadamente girafas (animal presente num dos países mais afectados com a malária, a África) e insectos.
A paleta cromática foi previamente escolhida, de acordo com as cores utilizadas em África, mais especificamente na Tanzânia. Com cores primárias suaves (onde predomina o branco e o cru), a contrastar com cores secundárias mais fortes e chamativas, de forma a elucidar as mensagens/ símbolos importantes presentes em todos os babygrows.
As formas foram escolhidas mediante um estudo feito em algumas das marcas presentes na pesquisa conceptual. O modelo predilecto dos pais, segundo empregadas da loja, é o modelo em que existe apenas duas aberturas, a da entre as pernas e nas costas junto ao pescoço, pois segundo estas, as molas de pressão causam desconforto e irritações na pele do bebé.
Apresenta-se de seguida alguns desenhos iniciais do projecto, através dos quais se explorou as formas, silhueta e proporção em relação ao babygrow e ao corpo do bebé.
Fig.1.3 Esboços com apontamentos de cor e grafismos
Após o desenho dos esboços, foram realizadas as ilustrações, para se puder ver melhor os pormenores técnicos e estéticos dos babygrows. A figura abaixo mostra algumas das ilustrações presentes no catálogo. Note-se que todos os modelos são unissexo e dotados de mensagens que carregam signos alusivos á protecção da malária.
Fig 1.4 Algumas ilustrações do catálogo
Depois de realizadas as ilustrações, o passo seguinte foi a escolha do modelo para a realização do protótipo. O protótipo escolhido foi o da figura 1.5.
Fig 1.5 A) Ilustração do modelo escolhido para a confecção do babygrow, B)Versão em manga-curta do modelo escolhido.
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Referências
1. Cunico, et al., Fármacos antimalariais - história e perspectivas. Quimioterapia-Revisão, Brasil, 2008.
2. Freitas et al., Malária não complicada por Plasmodium vivax e P. Falciparum no Brasil: evidências sobre fármacos isolados e associações medicamentosas empregados em esquemas terapêuticos recomendados pelo protocolo terapêutico oficial. Cadernos de Saúde Publica, Brasil, 2007.
3. Russel et al., Increased proportions of outdoor feeding among residual malaria vector populations following increased use of insecticide-treated nets in rural Tanzania. Malaria Journal, Biomed Central, 2011.
4. Ferraz, R.V.J., Quimioterapia da malária: síntese de duplos pró-Síntese Orgânica, Seminário em Síntese Orgânica, Porto, 2002.
5. Ferreira, I.D., Estudos de Susceptibilidade à Artemisinina e Derivados em plasmodium falciparum. Instituto de higiene e medicina tropical universidade nova de Lisboa, Lisboa, 2008.
6. Camargo, E.P., Malária, maleita, paludismo. São Paulo, 2003.
7. Cambournac F., Contribution to the history of malaria epidemiology and control in Portugal and some other
Parasitology, vol. 36(1-2): pp.215-22, 1994. 8. Ministério da Saúde, Manual de Medicina das Viagens.
2005-7. 9. Neves, D.P., Parasitologia humana. 11ª edição, Ed.
Atheneu, 2005. 10. Rodrigues, A.G., Malária e Babesiose. Faculdade
de Medecina da Universidade do Porto-Microbiologia, Porto;
11. WHO, Global malaria control and elimination, report of a technical review. Acedido em 17 de Março de 2011. (http://apps.who.int/malaria/docs/elimination/MalariaControlEliminationMeeting.Pdf)
12. WHO, Malaria case management: Operations manual. Global Malaria Programme, Geneva, 2009.
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Development of a cap to support the mobility of visually disabled people
N. Nascimento1, R. Salvado1, F. Borges2 and P. Araújo3
1Textile and Paper Materials Research Unit, University of Beira Interior, 6201-001 Covilhã, Portugal
2Campus João Pessoa, Instituto Federal de Educação, Ciência e Tecnologia da Paríaba, 58015-430
João Pessoa Paraíba, Brasil
3Institute for Telecommunications, University of Beira Interior, 6201-001 Covilhã, Portugal
Abstract There are about 148,000 blind people in Brazil and approximately 2.4 million people who claim to have great difficulty seeing. This large contingent needs support of assistive technologies that allow greater mobility and greater accessibility to public facilities, which represents social inclusion and improved quality of life. This paper presents the development of a fashion accessory a cap to alert visual disabled people for shock of the upper body with a frontal obstacle that was not detected by the touch of the stick that is typically used. It is a micro controlled cap with built-in circuit, optical obstacle detector and acoustic/tactile alarm. The developed caps were tested with 22 volunteers. One administered a questionnaire about the characteristics that volunteers considered as most important. Preliminary results show that most of the volunteers were easy to learn how to operate the cap and consider of great importance the possibility of turn on and off each one of the actuators (vibration motor and buzzer) independently. Finally, the questionnaire confirmed general opinion that the device should be used in conjunction with the cane, and not as a substitute for it. Keywords: Obstacles sensor, product design, visually impaired, assistive technology, urban mobility.
Introduction
Data from the 2000 census show that in Brazil, about 14.5% of the population carries some form of disability. The Northeast is the region with the highest percentage of people with disabilities: 16.8%. Thus, there are about 148,000 blind people in Brazil and approximately 2.4 million people who claim to have great difficulty seeing. The Northeast region concentrate around 57,400 people who declared themselves blind [1]. This large group of citizens needs assistive tech-nologies to allow an autonomous mobility in urban environments and an autonomous access to public facilities. According to the Technical Assistance Committee of the Special Secretariat for Human Rights (Presidency of Brazil), assistive technology includes products, resources, methodologies, strate-gies, practices and services that aim to promote func-tionality related to the activity and participation of persons with disabilities or reduced mobility, promot-ing their autonomy, independence, quality of life and social inclusion [2].
The most common assistive technology product among visually impaired people is the cane, which allows detection of lower obstacles, helping this way an independent walk. For a very short minority, it is complemented by a guiding dog. Nowadays, there exist several smart canes that include electronic de-vices for helping and guiding mobility. For instance the NaVi-Cane [3], developed by Sungbae Jo, that integrates sensor and GPS is one of the models al-ready available on the market. However, the canes don´t detect higher obstacles that are the cause of several accidents. Moreover, such canes are not af-fordable by the majority of the Brazilian population who needs. In this context, fashion products, as for instance smart clothes or smart accessories, that integrate electronic components such as microcontrollers, tiny sensors and actuators, might be considered as assis-tive technology products. These smart fashion prod-ucts may complement the function of a regular cane, helping the detection of obstacles in a very discrete and non stigmatizing way. The work of Leonardo Gontijo, consisting on the development of sensors to be hold in different parts of the body, has been re-ported in social media [4] as a promising assistive technology solution. However, these type of products still remain unaffordable to the majority of the Bra-zilian visually impaired population. This paper presents the development of a cap that integrates a sensor of obstacles and an alert system. It is made of Brazilian sustainable materials and may be produced and commercialized at an affordable price. Some preliminary studies of its functionality are presented.
Development of the sensor cap
The cap is a fashion accessory universally used. It is very common among the population of the North-east Brazilian region to protect users from strong sunshine. Therefore, it appears to be a good acces-sory to be transformed integrating sensors that will allow the detection of frontal and high obstacles. The main desirable features of this cap are:
bstacles;
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The electronic components
In order to be able to achieve the functional fea-tures, the cap should integrate a sensor, to detect obstacles, and should also integrate actuators, to inform the user about the risk of impact. The electronic devices should be as small, thin and light as possible in order to be embedded in the cap without constraining the user. In the cap here presented, the chosen sensor is an optical one, instead of the larger sound sensor that has been used in the smart canes above referred. The optical sensor used is the model GP2Y0A02YK0F, produced by Sharp. It senses object from 20 to 150 cm distance. Two devices are used to alert for existing frontal obstacles: a standard buzzer and a standard mechanical vibrator. They are positioned in both lateral sides of the cap. They can be used together or separately to alert the user for the risk of impact. Therefore, the user can choose the alert system he prefers or the one that is more perceptible according to the ambience. For instance in noisy ambiences the vibrator is preferred as it might be more perceptible. In order to connect the sensor to the actuators, the electronic platform named Arduino Lillypad is used. In plus to it, two extra plaques are used to activate each actuator: the buzzer and the vibrator. The following figure presents the scheme of the cap, integrating the electronic devices, including the batteries.
Figure 1 Scheme of the sensor cap. A specific software allows to correspond the sensed distance to the frequency of the actuators. Therefore, the sound and vibrations are slowly re-peated at 150 cm distance, faster repeated at 100cm and even faster repeated at 50 cm distance from the obstacle. The cap
The cap should incorporate the electronic devices in fixed positions that must be accessible, to allow future
maintenance of the electronic circuit, battery replacement and so on. Preliminary prototypes were made by adapting standard caps in order to integrate on them the elec-tronic devices. Further, several specific models of the caps have been drawn to minimize the intrusive inte-gration of the devices and to facilitate the usage of the cap. Therefore, all drawn models of the caps have internal pockets that accommodate the electronic devices. Moreover, in all models the interior is easily acceded by opening a zipper or a Velcro tape. Several materials were considered, most of all Brazilian materials, aiming to strength sustainable local productions. Figure 2 shows the interior of one of the
positioning of the several electronic devices are pointed: 1 frontal pocket for optical sensor; 2 left pocket for the vibration motor drive; 3 right pocket for the acoustic transducer drive; 4 back pocket for rechargeable batteries module; 5 zipper to close and protect the devices.
Figure 2 The interior of a cap made of goat leather Figure 3 shows the tested model that is made of goat leather, tilapia fish leather and dourada fish leather.
Figure 3 The tested sensor cap
Field tests
The developed caps were tested among a popula-tion of 100 visually disabled persons, who attend the Association
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Fundação de Apoio aos Deficientes FUNAD, at João Pessoa, Paraíba, Brazil. The sample consists in 22 volunteers, disabled persons at ages in similar proportion to the population, being 50% of men and 50% of women. It was not considered the origin or cause of the disability. It was not considered the education level neither was religious or social aspects. The ergonomic aspects of the sensor cap were easily measured [5] with field tests that comprise two set of tests:
1. the training tests, with the aim of learning how to use the cap;
2. the verification tests, with the aim of test-ing the efficiency of the sensor cap.
For the training tests, the volunteers, using the cap, were sitting and were asked to identify some obstacles that were placed at determined distances: 50, 100 and 150 cm. This training was repeated 10 times. For the verification tests, the volunteers, using the cap, were moving inside a pavilion were five obstacles were previously prepared. The volunteers were asked to detect the obstacles and to identify their distance from it. This test was repeated 5 times. Moreover, a questionnaire was filled in order to inquiry
some important features of the cap. And interviews were made to collect personal experiences of usage.
Results
Considering the 10 attempts of the training tests, volunteers were on average able to identify:
94,1 % of the obstacles placed at 50 cm; 95,0% of the obstacles placed at 100 cm; 92,3% of the obstacles placed at 150 cm.
Considering the 5 repetitions of the verification tests by each 22 volunteers, obstacle:
I was identified on 96,4% of attempts; II was identified on 86,4% of attempts; III was identified on 93,6% of attempts; IV was identified on 93,6% of attempts; V was identified on 93,6% of attempts.
Therefore, results show that most of the volunteers have easily learned how to operate the sensor cap. The answers to the questionnaire have shown that 18 of the 22 volunteers preferred to have both actua-tors (vibration motor and buzzer). For 4 volunteers the noise of the buzzer was uncomfortable and dis-tressed. Moreover, in open questions the majority of volunteers revealed they appreciate the possibility to independently switch on and off each of the two actuators. The interviews allow confirm the idea that the sen-sor cap is efficient and helpful when used in com-plement of the cane. Some interviewers loved the cap and would like to use it daily. Some would prefer more discrete caps than the ones tested or even more discrete products than the cap is.
Conclusions
One may conclude the optical sensor is efficient to detect frontal obstacles at 50, 100 or 150 cm distance. Moreover, the differentiation of the alarm signal for obstacles at 50, 100 or 150 cm distance are clear and helpful. The large majority of volunteers have easily and quickly learned how to use the sensor cap. They appreciate the possibility to independently activate each of the two actuators. Most of volunteers use both actuators. The sensor cap might have a lower price than other similar products of assistive technology. This makes the sensor cap more affordable which might enhance its dissemination among the visual disabled people. By this way, the sensor cap might facilitate urban mobility, improve autonomy and help social inclusion of a large number of citizens. This work shows how design might promote social inclusion and might reduce stigmas, helping visual disabled people to live better.
References [1] (IBGE, 2000). IBGE Instituto Brasileiro de
Geografia e Estatística. Relatório do Censo Demográfico 2000: Características gerais da população, resultado da amostra. Access on 30 /01/2011 <http://www.ibge.gov.br/censo/>
[2] (CAT, 2000) Comitê de Ajudas Técnicas. Acessed on 25/01/2011,<http://www.acessobrasil.org.br/CMS08/seo-conceito-19.htm>.
[3] (IFCA, 2009.) IFCA INTERNATIONAL FORUM CONCEPT AWARD (2009). Access on 30/01/2011, <http://www.designophy.com/newslog/article.php?UIN=1000001484>.
[4] BASSETTE, F. (2009). Sensores podem substituir bengalas para cegos. Folha de São Paulo / Universo Online (UOL). Acessado em 22 de abril de 2011, em <http://www1.folha.uol.com.br/folha/equilibrio/noticias/ult263u601024.shtml>.
[5] R. J. FEENEY and MARGARET D. GALER Ergonomics Ergonomics research and the disabled, Volume 24, Issue 11, 1981, pp 821-830.
Acknowledgements
The authors wish to thank Jonas Ieno, from the company Sat Soluções (www.satsolucoes.com.br), for his help preparing the software used.
The authors wish to thank all the volunteers who participated in this study for their contributions to test and improve the sensor cap.
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Modelização da resistência à abrasão de tecidos de lã e poliéster em função das características estruturais de fios convencionais
N. Monteiro, R. Miguel
Departamento Têxtil, Unidade de Investigação Materiais Têxteis e Papeleiros Universidade da Beira Interior, Covilhã
Resumo
Este trabalho de investigação teve por objectivo estudar o desempenho de diversos tecidos mistos de lã e poliéster, no que diz respeito à resistência à abrasão. Através de adequado tratamento estatístico procedeu-se à determinação das correlações entre as características estruturais dos fios e dos tecidos e a propriedade de desempenho resistência à abrasão . Os modelos matemáticos encontrados constituem uma poderosa ferramenta para, na fase de projecto, simular a solução optimizada de construção técnica do tecido.
Abstract
This research work aimed to study the performance of several wool and polyester blended fabrics, regarding to abrasion resistance. Through appropriate statistical analysis the determination of correlations, between structural characteristics of yarns and fabrics and the abrasion resistance performance property, are conducted. The mathematical models found are a powerful tool, for the engineering design stage, to simulate the optimal solution of the fabric technical construction.
Introdução
A resistência à abrasão de um tecido depende de vários factores, tais como, as propriedades das fibras, número e estrutura do fio, ligamento e massa por metro quadrado do tecido e tipo de acabamento (Galbraith, 1975). Como é do conhecimento geral, a abrasão é produzida pela fricção do tecido contra tecido ou contra outros agentes abrasivos. A abrasão do tecido é um processo que se desenvolve em duas etapas: a primeira afecta principalmente a aparência do tecido; a segunda, que se manifesta mais tarde, afecta a estrutura interna do tecido. A resistência à abrasão mede-se normalmente pelo número de ciclos que causam a rotura dos fios, mas também pode ser medida pela perda de massa do tecido depois de um determinado número de ciclos de abrasão. A abrasão dos tecidos durante o uso é difícil de definir devido às diferenças existentes entre os vários utilizadores (Barella et al., 1998). Vários estudos têm mostrado que o aumento da resistência à abrasão resulta do aumento do diâmetro e do comprimento das fibras, do aumento do número do fio e do aumento das densidades de fios e passagens. O efeito
destas características estruturais na resistência à abrasão, nem sempre é claro, pois, alguns estudos têm apresentado resultados contraditórios, devido ao facto de, em muitos casos ser difícil mudar uma característica estrutural dum tecido sem afectar as outras propriedades. A resistência à abrasão pode ser uma das propriedades que seja afectada por várias características de uma forma interactiva. Os diferentes resultados do comportamento dos tecidos à abrasão sugerem que a quantidade de fibras partidas aumenta quando existe uma maior área de contacto entre os fios e o material abrasivo. Assim, os tecidos em sarja tem inferiores resistências à abrasão do que os tecidos em tafetá. Por outro lado, verifica-se também que, os tecidos mistos de algodão e poliéster, fabricados com fibras de poliéster com um comprimento médio de 31,8 mm têm pior resistência à abrasão do que os tecidos fabricados com fibras de poliéster com um comprimento uniforme de 38,1 mm. Da mesma forma que tecidos fabricados com fibras de poliéster de 1,2 denier têm pior resistência à abrasão do que os tecidos fabricados com fibras de poliéster de 1,5 denier (Annis et al., 1992). Tanto as características da fibra como a geometria do tecido afectam a resistência à abrasão dos tecidos. Alguns polímeros são intrinsecamente mais resistentes à abrasão do que outros. O nível de torção do fio, o seu frisado e o ligamento do tecido afectam a resistência à abrasão. Fios com baixa torção apresentam uma maior superfície de contacto para com o tecido abrasivo. No entanto, dar pouca torção aos fios pode dar origem a que algumas fibras saiam do corpo do fio e sejam partidas durante a abrasão. Pelo contrário, elevadas torções reduzem a resistência à abrasão dos fios (Sulzer, 2001). De acordo com Onikov, (1992), a resistência à abrasão de qualquer tecido depende de factores importantes, tais como, a resistência do fio (tipo de fibra, número e estrutura) e da densidade de fios e de passagens do tecido. Contudo, depende também de factores estruturais, tais como o grau de flexão recíproco dos fios da teia e dos fios da trama que determina a superfície de contacto do tecido. O termo superfície do contacto do tecido diz respeito às porções de área de teia e de área de trama que tocam o abrasivo. Deste estudo, pode concluir-se, que os tecidos cuja superfície de contacto da teia é igual à superfície de contacto da trama têm por consequência, na globalidade, uma superior superfície de contacto, pelo que têm uma baixa perda de resistência, ou seja uma elevada resistência à abrasão.
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Barella et al. (1996) verificaram que quanto maior for a percentagem de poliéster em tecidos produzidos com fios de igual massa linear e com igual massa por metro quadrado, melhor a resistência à abrasão. Almetwally e Salem, (2010) referiram também, que a resistência à abrasão diminui com o aumento do coeficiente de torção dos fios.
Materiais e Métodos
Uma vez que as composições com maior interesse e aplicabilidade são 55% poliéster/45% lã e 60% lã/40% poliéster, fabricaram-se, em cada uma das referidas composições, oito amostras de fio convencional, número métrico (Nm) 2/46, constituídas por poliéster preto e lã branca (Monteiro, 2011). As amostras de fio diferem entre si na finura das fibras que as constituem, bem como na torção e na retorção, conforme se pode observar na Tabela 1:
Tabela 1 Características das amostras de fio
55%
Pol
iést
er/4
5% L
ã
Amostras de fio
Fibras componentes (PES/WO)
Torção e Retorção (v/m)
A 2,4 dtex/21,4 µ Z1=620 e S2= 700
B 2,4 dtex 21,4 µ Z1=720 e S2= 800
C 2,4 dtex/ 24,9 µ Z1=620 e S2= 700
D 2,4 dtex/ 24,9 µ Z1=720 e S2= 800
E 4,4 dtex/ 21,4 µ Z1=620 e S2= 700
F 4,4 dtex/ 21,4 µ Z1=720 e S2= 800
G 4,4 dtex/ 24,9 µ Z1=620 e S2= 700
H 4,4 dtex/ 24,9 µ Z1=720 e S2= 800
60%
Lã
/40%
Pol
iést
er
I 2,4 dtex/ 21,4 µ Z1=620 e S2= 700
J 2,4 dtex/ 21,4 µ Z1=720 e S2= 800
K 2,4 dtex/ 24,9 µ Z1=620 e S2= 700
L 2,4 dtex/ 24,9 µ Z1=720 e S2= 800
M 4,4 dtex/ 21,4 µ Z1=620 e S2= 700
N 4,4 dtex/ 21,4 µ Z1=720 e S2= 800
O 4,4 dtex/ 24,9 µ Z1=620 e S2= 700
P 4,4 dtex/ 24,9 µ Z1=720 e S2= 800
(Fonte: Monteiro, 2011) Com as várias amostras de fio foram fabricados tecidos nos três ligamentos básicos, mais utilizados na indústria laneira, sarja de 4 pesada, sarja de 3 pesada e tafetá, utilizando individualmente as 16 amostras de fio Nm 2/46, em cada um dos ligamentos. Todas as amostras foram tecidas no mesmo tear e ultimadas em simultâneo seguindo a sequência de operações aconselhada para um
acabamento rapado. Na Tabela 2, apresentam-se as características de construção dos tecidos.
Tabela 2 - Características de construção dos tecidos
Características Sarja 4 Sarja 3 Tafetá
Pente 75/4 95,3 90/2
Largura no pente (cm) 165 168 174
Densidade à teia (fios/cm) 30,0 28,5 18
Densida. à trama (pass/cm) 21,5 20,5 18
(Fonte: Monteiro, 2011) Todos os ensaios laboratoriais de controlo de qualidade foram realizados em condições de temperatura (20±2ºC) e humidade relativa (65±4%) controladas, de acordo com a Norma ISO 139:2005. A resistência à abrasão foi determinada no equipamento Nu-Martindale : Abrasion and Pilling Tester, de acordo com a Norma ISO 12947-2:1998. Dada a massa por unidade de superfície dos tecidos analisados, a pressão nominal aplicada foi de 9 KPa.
Resultados e Discussão
Na Tabela 3 apresentam-se os resultados encontrados para cada um dos ligamentos estudados, em ambas as composições.
Tabela 3 Resultados da resistência à abrasão (ciclos)
55%
Pol
iést
er/4
5% L
ã
Amostras de fio
Sarja de 4 Sarja de 3 Tafetá
A 50000 36000 47300
B 48000 35300 44700
C 51000 40700 45300
D 52000 38700 48000
E 83000 74000 82000
F 83000 74000 84700
G 88000 73300 85000
H 86000 82000 83000
60%
Lã
/40%
Pol
iést
er
I 36000 33300 32000
J 36000 31000 34000
K 33000 34000 38000
L 36000 32000 34300
M 68000 62000 76700
N 76000 60700 75700
O 82000 63000 74000
P 76000 59500 78500
(Fonte: Monteiro, 2011) Da análise dos resultados obtidos verifica-se que:
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- Independentemente do ligamento e da composição, os resultados obtidos entre os tecidos produzidos, quer com fios com torções mais elevadas, quer com fios com torções mais baixas, mostram que na maioria dos casos, existe uma tendência para piores desempenhos dos tecidos produzidos com fios com torções mais elevadas, o que vem confirmar os estudos efectuados por Almetwally e Salem (2010) e Sulzer (2001). - Independentemente do ligamento, os tecidos 55% poliéster/45% lã, apresentam valores superiores aos tecidos 60% lã/40% poliéster. Estes resultados devem-se à maior representatividade das fibras de poliéster na mistura e à maior resistência destas fibras comparativamente à das fibras de lã; - Independentemente do ligamento, os valores da resistência à abrasão dos tecidos produzidos com poliéster de 4,4 dtex praticamente duplicam comparativamente aos valores dos tecidos produzidos com poliéster de 2,4 dtex, o que demonstra claramente a influência do diâmetro da fibra nesta propriedade. Estes resultados vêm corroborar o estudo realizado por Annis et al., (1992) que revelou, que os tecidos produzidos com fibras de poliéster de 1,2 dtex têm piores resistências à abrasão do que os tecidos produzidos com fibras de poliéster de 1,5 dtex; - Nos tecidos 55% poliéster/45% lã, o ligamento que permite melhor desempenho é a sarja de 4 pesada, seguido do tafetá e por último a sarja de 3 pesada. Este comportamento dos tecidos verifica-se, quer se utilize poliéster de 4,4 dtex, quer de 2,4 dtex; - Nos tecidos 60% lã /40% poliéster, produzidos com poliéster de 2,4 dtex, os três ligamentos apresentam uma gama de valores muito similar. Contudo, verifica-se também uma tendência para a sarja de 3 pesada apresentar piores desempenhos; - Nos tecidos 60% lã/40% poliéster, produzidos com poliéster de 4,4 dtex, quer a sarja de 4 pesada, quer o tafetá, apresentam, em termos médios, comportamento idêntico. Quanto à sarja de 3 pesada, verifica-se que o seu desempenho é inferior ao dos outros dois ligamentos. Estas três últimas constatações mostram que a sarja de 3 pesada é o ligamento que apresenta resistências à abrasão mais baixas comparativamente ao tafetá e à sarja de 4 pesada. Contudo, não foi possível encontrar qualquer justificação cientifica e/ou técnica para estas diferenças de comportamento dos tecidos. Através de adequado tratamento estatístico procedeu-se à determinação das correlações entre as características estruturais dos fios e dos tecidos e a propriedade de desempenho resistência à abrasão . De acordo com os coeficientes de correlação encontrados, efectuou-se uma regressão linear múltipla, de modo a encontrar a equação matemática, que melhor se ajuste aos valores
experimentais. A equação de regressão (1) relaciona a resistência à abrasão (RA) da totalidade dos tecidos com as características estruturais, apresentando um coeficiente de determinação R2=0,8574.
RA (ciclos) = 19274*DPL 8549 (1)
onde: RA resistência à abrasão DPL massa linear da fibra de poliéster A validação do modelo matemático efectuou-se através de correlações entre os valores experimentais e os valores teóricos calculados através da equação (1), conforme mostra o Gráfico 1.
Gráfico 1 Correlação entre a RA experimental e a RA teórica, (Fonte: Monteiro, 2011)
A correlação entre os valores experimentais e os valores teóricos mostra que existem dois grupos de tecidos com desempenhos significativamente diferentes. O primeiro, com valores de desempenho inferiores, corresponde ao grupo de tecidos produzidos com poliéster de 2,4 dtex, enquanto o segundo, com valores de desempenho bastante superiores, corresponde ao grupo de tecidos produzidos com poliéster de 4,4 dtex. Por outro lado, verifica-se ainda que dentro de cada grupo de tecidos os valores experimentais apresentam uma amplitude bastante elevada, o que significa que existem outras variáveis que influenciam essas diferenças de desempenho. Assim, e uma vez que a equação de regressão (1), não explica satisfatoriamente esta propriedade, apresentam-se de seguida, as equações de regressão, bem como os gráficos que mostram a correlação entre os valores experimentais e os valores teóricos encontrados para os grupos de tecidos produzidos com poliéster de 2,4 dtex e com poliéster de 4,4 dtex, respectivamente.
A equação de regressão (2) relaciona a resistência à abrasão dos tecidos com poliéster 2,4 dtex (RA 2,4 dtex), com as características estruturais, apresentando um coeficiente de determinação R2=0,8490. RA 2,4 dtex (ciclos) = 766,21*PL+182,12*DLA 206,02*MM2+17092*AM+20602 (2)
99
onde: RA 2,4 dtex Resistência à abrasão dos tecidos com poliéster de 2,4 dtex PL percentagem de poliéster na mistura DLA diâmetro da fibra de lã MM2 massa por metro quadrado do tecido AM alinhavo médio
No Gráfico 2 mostra-se a correlação entre os valores teóricos, obtidos pela equação (2) e os valores experimentais, resultantes de ensaios laboratoriais.
Gráfico 2 Correlação entre a RA experimental 2,4 dtex e a RA teórica 2,4 dtex, (Fonte: Monteiro, 2011)
O coeficiente de determinação da equação de regressão é aceitável o que mostra que 84,9% desta propriedade é explicada pelas variáveis da equação. A equação de regressão (3) relaciona a resistência à abrasão dos tecidos com poliéster 4,4 dtex (RA 4,4 dtex), com as características estruturais, apresentando um coeficiente de determinação R2=0,8616. RA 4,4 dtex (ciclos) = 772,82*PL+598,76*DLA 357,22*MM2+26716*AM+71448 (3)
No Gráfico 3 mostra-se a correlação entre os valores teóricos, obtidos pela equação (3) e os valores experimentais, resultantes de ensaios laboratoriais.
Gráfico 3 Correlação entre a RA experimental 4,4 dtex e a RA teórica 4,4 dtex, (Fonte: Monteiro, 2011)
O coeficiente de determinação da equação de regressão é aceitável o que mostra que 86,16% desta propriedade é explicada pelas variáveis da equação. Por outro lado, verifica-se também que os coeficientes de correlação entre os valores experimentais e os valores teóricos são aceitáveis, o que revela uma boa aproximação. O facto destes coeficientes de correlação serem exactamente iguais aos coeficientes de determinação das equações de regressão vem comprovar a forte relação entre as variáveis dos modelos e a resistência à abrasão.
Conclusões
A resistência à abrasão dos tecidos é tanto maior quanto maior for a massa linear da fibra de poliéster. O facto dos tecidos em sarja de 3 apresentarem desempenhos mais baixos do que os tecidos em sarja de 4 e tafetá, sugere que este ligamento é o menos adequado, para tecidos cuja resistência à abrasão seja o requisito técnico mais relevante.
Referências Bibliográficas
1. Galbraith, R. L., (1975), Abrasion of Textile Surface . Schick, M., Surface Characteristics of Fibers and Textiles Parte I, pp. 193-221. Nova York: Marcel Dekker.
2. Barella, A., Manich, A. M., Castellar, M. D., Sauri, R. M., Miguel, R. A. L., Domingues, P., (1998), La Resistência a la Abrasion y la Pérdida de Massa de Tejidos da Lana y Mesclas, Quando se Utiliza el Abrasímetro Martindale , Revista de la Industria Textil, nº360, pp. 50-58.
3. Annis, P. A., Bresee, R. R., Cooper, T. R., (1992), Influence of Textile Structure on Single Fiber Transfer from Woven Fabrics , Textile Research Journal, Vol. 62, nº5, pp. 293-301.
4. Sulzer Textil Limited Swizerland, (2001), Fabric Structure, Properties and Testing , pp. 361-373.
5. Onikov, E. A., (1992), Cotton Fabrics with Higher Resistance to Abrasion , Melliand Textilberichte, Vol. 73, nº1, pp. 37-38.
6. Barella, A., Miguel, R., Manich, A., Castellar, M., (1996), Influencia de las Características Estructurales sobre las Propiedades de Uso y Conforto de los Tejidos de Lana y sus Mesclas , Revista de la Industria Textil nº 340, pp.55-70.
7. Almetwally, A. A., Salem, M. M., (2010), Comparison Between Mechanical Properties of Fabrics Woven from Compact and Ring Spun Yarns , Autex Research Journal, Vol. 10, nº1, pp. 35-40.
8. Monteiro, N., (2011), Estudo das características estruturais de fios convencionais para optimizar as propriedades mecânicas e de superfície de tecidos mistos de lã e poliéster , Dissertação de Mestrado em Engenharia Têxtil, Universidade da Beira Interior.
101
POSTERS
103
Indocarbocyanine Supports for Protein Separation
D. Almeida1, F. Sousa1, P. Almeida1, R. E. F. Boto1 1Health Sciences Research Center, University of Beira Interior, 6201-001 Covilhã, Portugal
Abstract The synthesis of three N,N`-dicarboxyalkylindocarbo-cyanines are described as well their immobilization onto cellulose beads by a curing method envisioning their use as a biomimetic ligand in dye-affinity chromatography. These matrices were used as chromatographic supports and the dye-affinity interaction with the standard proteins bovine serum albumin, α-chymotrypsin and lysosyme was analyzed. The influence of the mobile phase composition on the chromatographic behavior of these standard proteins was also studied.
Introduction Perkin´s mauve discovery in 1856 changed the dye synthesis industry. Since this discovery, cyanines have been synthesized with several purposes, due to their special characteristics. In all these characteristics, its easy synthesis and their relatively elevated stability have been responsible for their application in diverse fields such as photography and biomedical, among others [1]. A typical cyanine molecule may be defined as a mono acid salt, in which the nitrogen atoms of the two heterocyclic nuclei are linked by a conjugated chain of double bonds. Accordingly to this definition, each compound is regarded as a resonance hybrid of two canonical structures and no single formula is a complete representation. Nevertheless for simplification, the structure is normally presented as possessing a nitrogen tertiary atom and another quaternary [2]. A number of textile dyes, known as reactive dyes, have been used as ligands for the protein purification in dye affinity systems, since they bind a variety of proteins in a selective and reversible manner [3]. Affinity chromatography (AC) separates proteins on the basis of a reversible interaction between a protein and a specific ligand coupled to a chromatographic matrix. The technique offers high selectivity, high resolution, and usually high capacity for the protein(s) of interest [4]. The indocarbocyanines with two carboxylic groups makes these dyes potentially reactive and able to bonding onto hydroxylic macromolecules as cellulose, by an esterification method. The molecular structure of these dyes offers multiple possibilities for the interaction at many sites with the target proteins [5]. In this paper are presented the synthesis of three indocarbocyanines that were immobilized onto a cellulose matrix by a esterification method. These
indocarbocyanines were studied as ligands in dye affinity chromatography. Materials and Methods All the reagents were purchased from Sigma Aldrich and of the highest purity available, used as received and were purchased from Sigma Aldrich. Solvents were of analytical grade and were dried over 3 Å molecular sieves prior to use. Polypropylene econo-pac chromatographic columns were acquired from BIO RAD. Indocarbocyanine synthesis: Quaternization of compounds 1a-c was achieved by a melting process at 150º C with 1 eq. of 2,3,3-trimethylindolenine (a-b) or 1,1,2-trimethylbenz[e]indol (c), in the presence of 1.1 eq. 11-bromoundecanoic acid or 5-bromovaleric acid (Scheme 1). The reaction was completed after 48h and the solids were recrystallized from methanol/diethyl ether.
Scheme 1: Indocarbocyanines synthesis
The indocarbocyanines (3 a-c) were obtained by refluxing the quaternary ammonium salt (2 a-c) and triethyl orthoformate (2.1 eq.) in pyridine (10 mL /g salt) with posterior change of counter-ion.
1-3 a) b) c) R H H C* R’ H H C* n 4 10 10
N
RR'
N
R
R'
(CH2)n
COOH
I N
R
R'
(CH2)n
COOH
Br(CH2)nCOOH
1º (C2H5O)3CH
2º H2SO4 , KI
BrN
R
R'
(CH2)n
COOH1
, pyridin,
104
The resulting compound was washed several times with diethyl ether and recrystallized from methanol obtaining the indocarbocyanines 3 a-c. Indocarbocyanine immobilization onto cellulose: Dried beaded cellulose was well mixed with the indocarbocarbocyanine dye in an agate mortar. The following mixtures were prepared: Matrix 1 - 1g indocarbocyanine 3b + 4g cellulose beads Matrix 2 – 2g indocarbocyanine 3b + 4g cellulose beads Matrix 3 – 1g indocarbocyanine 3c + 4g cellulose beads Matrix 4 – 2g indocarbocyanine 3c + 4g cellulose beads Matrix 5 – 2g indocarbocyanine 3a + 4g cellulose beads This mixtures were transferred to a silicate specimen tube, wetted with N,N-dimethylformamide (DMF) to obtain an intimate mixture and covered with perforated aluminum foil. The mixture was then inserted into the reaction vessel and heated under vacuum, as described in fig.1.
Fig 1 - Cellulose derivatization conditions.
The beaded cellulose samples so obtained were sequentially washed off with several portions of DMF and ethanol and were submitted to Soxhlet extraction with the same solvents until no leakage was observed. The resulting samples were then dried for at least 24 h at 50°C under vacuum and over phosphorus pentoxide. Affinity chromatography with indocarbocyanines as ligands: It was prepared protein solutions of BSA, α-chymotrypsin and lysozyme with concentrations of 12.5, 18.75 and 25 mg/mL in10 mM Tris–HCl at pH 8. The dyed matrices (1 mL) were packed in a 1.5 × 12 cm econo-pac column and equilibrated with 10 mM Tris–HCl at pH 8. It was performed preliminary essays to verify de ideal concentration of protein to inject into each column. Then, it was performed essays with various concentrations of NaCl (10mM, 0.1M and 0.2M) solutions to verify ionic interactions trying to separate the protein in different conditions. It was performed a pH study, with acetate and Tris-HCl buffer solutions (pH 4, 5, 6 and 7). To verify hydrophobic interactions it was performed essays with ammonium salt. At all essays performed the protein solution (34 μL) was loaded onto the column and to promote the desorption of bounded protein was performed
the elution with various concentrations of NaCl buffer, with addition of buffers at different values of pH and testing hydrophobic conditions by addition of ammonium salt. Fractions of 0.5 mL of eluate were collected and the absorbance was measured at 280 nm.
Results and Discussion All indocarbocyanines synthesized were obtained in good yields rounding 60-71% and were fully characterized.
Elemental analysis revealed a reduced amount of ligands immobilized onto cellulose. In preliminary studies it was optimized conditions to proteins BSA, lysozyme and α-chymotrypsin and as we can see in fig 2, for matrix 1, 2, 3 and 5 (injection of 12.5 mg/mL protein) and matrix 4 (injection of 18.75 mg/mL protein) lysozyme was retained onto matrix with Tris–HCl 10 mM buffer and eluted with adition of NaCl 1 M.
Fig 2 – Affinity chromatography with indocarbocyanines as ligands in A - matrix 1, 2, 3 and 5. B – matrix 4. Injection of Lysozyme. α-chymotrypsin revealed a similar behavior. BSA protein revealed to establish a strong interaction with all matrices, this protein was retained onto matrices with Tris–HCl 10 mM buffer and it wasn’t promoted elution with addition of NaCl 1M. Trying to promote the elution of the two proteins lysozyme and α-chymotrypsin in different conditions it was performed a study of variation NaCl concentration in 10mM, 0.1M and 0.2 M. It was observed that lysozyme have similar behavior as α-chymotrypsin being promoted the total elution with 0.1M of NaCl concentration as we can see in fig 3. It was promoted partial elution with NaCl 10mM solution. This protein behavior was observed in all matrixes in identical manner.
0
0,2
0,4
0,6
0,8
1
0 0,2 0,4 0,6 0,8
1 1,2
0 5 10 15
[NaC
l] (M
)
Abs
(280
nm)
Fracções (mL)
0 0,2 0,4 0,6 0,8 1
0 0,2 0,4 0,6 0,8
1 1,2
0 5 10 15
[NaC
l] (M
)
Abs
(280
nm)
Fracções (mL)
With vacuum Without vacuum
A
B
105
Fig 3 – Affinity chromatography with indocarbocyanines as ligands. A - matrix 4 with injection of lysozyme. B – matrix 4 with injection of α-chymotrypsin It was performed a study of pH variation. As we can see in fig 4, at pH4, with injection of lysozyme in A, and α-chymotrypsin in B, into the matrix 4, it was promote interaction with the matrix when injected 10mM Tris-HCl solution at pH 8 and total elution was achieved with acetate tampon solution at pH 4.
Fig 4 – Affinity chromatography with indocarbocyanines as ligands in a pH study. A - matrix 4 with injection of lysozyme. B – matrix 4 with injection of α-chymotrypsin. The pH study reveals that the standard proteins lysozyme and α-chymotrypsin have the same chromatographic behavior in all matrixes in elution conditions at pH 4, 5, 6 and 7. BSA reveals to establish a strong matrix interaction, maintaining this interaction with addition of acetate buffer solution at pH 4. There weren’t established the ideal conditions to separate proteins. In a hydrophobic approach, with addition of ammonium salt 1,5M, as we can see in fig 5, there is no interaction of the proteins lysozyme and α-chymotrypsin with matrix 4 in hydrophobic conditions. BSA reveals to establish strong interactions with matrixes and it wasn’t promoted
elution with addition of ammonium salt 1,5M neither with addition of Tris-HCl 10mM pH8.
Fig 5 – Affinity chromatography with indocarbocyanines as ligands in hydrophobic conditions. A - matrix 4 with injection of lysozyme. B – matrix 4 with injection of α-chymotrypsin.
Conclusions The three synthesized indocarbocyanines were synthesized with good yields.
Elemental analysis revealed a reduced amount of ligands immobilized onto cellulose.
Affinity chromatography with indocarbocyanines as ligands revealed that standard proteins lysozyme, α-chymotrypsin and BSA establish ionic interactions with all matrixes. It was not possible to establish different conditions to separate the three standard proteins.
References [1] Zollinger H., Color Chemistry: Syntheses, Properties and Aplications of Organic Dyes and Pigments, 2nd ed., VCH, Weinhein, 1991 [2] Hamer F. M., The cyanine dyes and related compounds, Wiley, London, 1964. [3] Denizli A., Piskin E., J Biochem Bioph Meth 49 (2001) 391-416. [4] Affinity Chromatography: Principles and Methods, Amersham Bioscience, 2002. [5] Boto R. E. F., Anyanwu U, Sousa F., Almeida P., Queiroz J. A., Biomed Chromatogr 23 (2009) 987-993.
Acknowledgements The authors are grateful to FCT (Lisbon), for financial support PTDC/QUI-QUI/100896/2008.
0
0,2
0,4
0,6
0,8
1
-0,2 0
0,2 0,4 0,6 0,8
1 1,2
0 5 10 15 20
[NaC
l] (M
)
Abs
(280
nm)
Fracções (mL)
0 0,2 0,4 0,6 0,8 1
0 0,2 0,4 0,6 0,8
1 1,2
0 10 20
[NaC
l] (M
)
Abs
(280
nm)
Fracções (mL)
0
2
4
6
8
0 0,2 0,4 0,6 0,8
1 1,2
0 10 20
pH
Abs
(280
nm)
Fracções (mL)
0
2
4
6
8
0 0,2 0,4 0,6 0,8
1 1,2
0 10 20
pH
Abs
(280
nm)
Fracções (mL)
0
0,5
1
1,5
0 0,2 0,4 0,6 0,8
1 1,2
0 5 10 15
[SA
] (M
)
Abs
(280
nm)
Fracções (mL)
0
0,5
1
1,5
0 0,2 0,4 0,6 0,8
1 1,2
0 5 10 15
[SA
] (M
)
Abs
(280
nm)
Fracções (mL)
A
B
A
B
A
B
106
Novos suportes para cromatografia de afinidade por síntese total de cianinas na matriz cromatográfica. Avaliação da contribuição de cada uma das partes na
afinidade ligando-proteína
L. P. Alves 1, S. S. Ramos 1, R. E. F. Boto 2, P. Almeida 2
1UMTP - Unidade de Materiais Têxteis e Papeleiros e Departamento de Química, Universidade da Beira Interior, Rua Marquês d’Ávila e Bolama, 6200-001 Covilhã, Portugal, 2CICS - Centro de Investigação em Ciências da Saúde eDepartamento de Química, Universidade da Beira Interior, Av. Infante D. Henrique, 6200-001 Covilhã, Portugal
Resumo A importância da purificação de biomoléculas tem fomentado um interesse crescente no desenvolvimento de novos suportes cromatográficos. Em estudos anteriores, foram desenvolvidos suportes cromatográficos obtidos por imobilização direta dos corantes cianínicos ao suporte inerte (matriz) através de um método de cura. No entanto, desconhecendo-se ainda muito sobre as multi-variáveis responsáveis pelas interações ligando-proteína quando são utilizadas cianinas em cromatografia de afinidade (CA), assim parece-nos fundamental o desenvolvimento de um método de imobilização das mesmas de modo a poder averiguar, passo a passo, a contribuição de cada uma das partes que, no seu conjunto, formam uma cianina, como potencial ligando para CA. Assim, nesta comunicação, é apresentada o recente desenvolvimento de novos suportes cromatográficos de celulose derivatizada com diferentes tipos de cianinas, bem como com os seus precursores em diferentes etapas da construção deste corante. Os diferentes suportes assim obtidos irão permitir uma posterior avaliação cromatográfica individual das partes que constituem este corante, a saber, braço espaçador hidrofóbico e sal de amónio heterocíclico.
Introdução Por definição, as cianinas são sais monoácidos em que dois núcleos heterocíclicos possuindo, pelo menos, um átomo de azoto, estão ligados por uma cadeia de ligações duplas conjugadas, pelo que a cadeia possui um número ímpar de átomos de carbono.1 Inicialmente utilizadas como corantes funcionais numa grande variedade de aplicações,2 a sua utilização como ligandos biomiméticos, em cromatografia de afinidade (CA),3 tem chamado a nossa atenção tendo em conta que como ligantes sintéticos, e quando comparados com os ligandos biológicos naturais, são mais baratos, mais fáceis de obter, são química e biologicamente inertes, sãofacilmente derivatizados e ligados a suportes cromatográficos e, finalmente, são potencialmente capazes de reconhecer seletivamente biomoléculas através de uma diversidade de interações a partir das diferentes partes desta classe de corantes. No seguimento desta ideia, foram preparados um conjunto de trimetinocianinas a partir das quais se explorou acapacidade de utilizar estes corantes catiónicos como
ligandos em CA.3 Nestes estudos foi descrito um método para ligar diretamente estes compostos à celulose, por esterificação, a partir de um método de cura a temperaturas na gama dos 180-240 ºC.3b Este método revelou-se altamente expedito, havendo ainda, no entanto, um caminho a percorrer até se ter um melhor entendimento das características das cianinas, e/ou partes químicas constituintes da sua estrutura, que são responsáveis, e em que extensão, pelas interações observadas entre estes ligandos e as proteínas alvo aseparar. Desta forma e com o objetivo de elucidar a contribuição individual de cada uma das partes que constituem um corante cianínico em CA, em termos de interações ligando-proteína, foram preparadas duas matrizes com os precursores das cianinas catiónicas, nomeadamente com obraço espaçador, a partir do éster de ��-bromoundecanoato de celulose (M1) e com o brometo de 2-metilbenzotiazol-N-(�-undecanoato de celulose)-3-io (M2). Posteriormente, a partir do suporte M2 foi sintetizada uma monometinocianina (M3) e uma carbocianina (M4), comprovando assim e de uma forma inequívoca, a ligação do sal de amónio quaternário àcelulose.
Materiais e Métodos O 2-metilbenzotiazole e o 2-metiltiobenzotiazole foram adquiridos comercialmente à Sigma-Aldrich.
Esquema 1- Síntese dos sais de amónio quaternários
107
A partir do 2-metilbenzotiazole foram obtidos os sais de amónio quaternários (1) e (2). O intermediário (3) foi obtido a partir do sal de amónio quaternário (2) e o sal de amónio quaternário (4) a partir do 2-metiltiobenzotiazole, conforme esquema 1, acima. Os compostos 1-4 foram sintetizados por métodos bem conhecidos na literatura. Para a derivatização da celulose microcristalina (1.0 g, 18.39 equiv. OH) com os precursores das cianinas foram utilizados dois métodos diferentes. Assim, no caso do ácido 11-bromoundecanóico (para obter M1), fez-se reagir o mesmo na presença de um excesso de cloreto de tionilo durante quatro horas, após o que se evaporou a mistura à secura.
O cloreto de ácido resultante foi dissolvido em 3 mL de N,N-dimetilformamida (DMF) e aquecido a 80 ºC durante um período de quatro horas (esquema 2, i)). No caso do sal de amónio quaternário (para obter M2), este foi bem misturado com a celulose em almofariz de ágata. A mistura resultante assim obtida foi transferida para um tubo de vidro coberto com papel de alumínio perfurado, ao qual se adicionou 3 mL de DMF com 5% de H2SO4, após o que se submeteu ao método de cura descrito anteriomente,3b até uma temperatura de 178ºC (esquema 2, ii)).
M 1
ii) Reação em banho de i) Método de cura
Br(CH2)10COOH
SOCl2, DMF, Δ
Esquema 2- Obtenção das matrizes M1 e M2
DMF com 5% de H2SO4
M 2
108
Estruturalmente, a matriz M1 corresponde ao suporte inerte (celulose) ligado a um braço espaçador. Este é geralmente utilizado para facilitar a ligação do ligando à molécula alvo uma vez que permite superar os efeitos de impedimento estereoquímico. A partir da matriz M2 em que o braço espaçador se encontra já ligado ao heterocíclico na forma de sal de amónio quaternário e, como tal, na forma do precursor geral típico das cianinas,
é possível obter esta classe de corantes já imobilizado. Consequentemente, foram obtidos os suportes M3 (tendo uma monometinotiocianina como ligando) e M4 (tendo uma trimetinotiocianina como ligando) por refluxo em piridina, durante 48 h, na presença de iodeto de 3-etil-2-metiltiobenzotiazol-3-io 2 (para obter M3) ou de iodeto de 2-[2-(acetil-fenilamino)vinil]-3-etilbenzotiazol-3-io 3 (para obter M4), conforme esquema 3.
Esquema 3- Obtenção das matrizes M3 e M4
M 3
M 4
Piridina, Δ
Piridina, Δ
M 2
109
Os suportes M1, M2, M3 e M4 depois de obtidos foram lavados com DMF e/ou metanol e submetidos a um processo de extração em Soxhlet utilizando os mesmos solventes de forma a garantir a remoção de vestígios de reagentes não ligados ao suporte. Por fim, as amostras foram secas durante 24 h a 50 ºC, sob vácuo, na presença de pentóxido de fósforo.
Resultados e Discussão A ligação dos diferentes compostos ao suporte foi qualitativamente confirmada por Espectroscopia de Infravermelho por Transformada de Fourier (FT-IR), por observação das bandas típicas dos C-H alifáticos, da banda C=O dos ésteres e/ou da banda C=C, conforme Tabela 1. Tabela 1 – Bandas típicas observadas por Infravermelho nos diferentes suportes preparados
Suporte cromatográfico
Bandas típicas ν (cm-1)
C-H alif. C=O (éster) C=C
M1 2854 1740 não aplic.
M2 2854 1717 não vis.
M3 2856 1717 1517
M4 2856 1717 1540
A quantificação na densidade de ligando está actualmente a ser determinada por Análise Elementar. O estudo das interações do tipo iónicas, hidrofóbicas, e outras, entre proteínas modelo e os ligandos imobilizados nos diferentes suportes cromatográficos assim obtidos, fazendo-se variar a concentração de NaCl e/ou do sulfato de amónio, e do pH, estão actualmente a decorrer.
Conclusões No seguimento deste estudo pioneiro, foi desenvolvido um novo procedimento para a obtenção de suportes cromatográficos com cianinas como ligandos para a CA. Além de ser um método alternativo ao desenvolvido anteriormente,3b tem a grande vantagem de se poder obter, a partir de uma mesma matriz com precursor, neste caso e como exemplo a matriz M2, uma enorme variedade de ligandos cianínicos imobilizados em celulose, tanto simétricos como assimétricos. A assimetria pode ser conseguida facilmente quer ao nível do núcleo heterocíclico, quer da cadeia alquílica ou alquil-substituída no átomo de azoto, e ainda de ambos. É ainda nossa convicção que se possam imobilizar algumas cianinas as quais, devido à sua conhecida instabilidade, não seriam possíveis de imobilizar de uma forma direta e clássica. É igualmente ainda nossa expectativa que a partir dos estudos cromatográficos em curso se possa concluir sobre
a contribuição individual de cada uma das partes constituintes das cianinas na interacção global com diferentes proteínas modelo e, desta forma, contribuir na elucidação sobre a relação estrutura do ligando/interações existentes na cromatografia de afinidade usando cianinas como ligandos.
Referências 1. Mishra, A.; Behera, R. K.; Behera, P. K.; Mishra, B. K.;
Behera, G. B. Chem. Rev. 2000, 100(6), 1973-2012.
2. a) Timtcheva, I.; Maximova, V.; Deligeorgiev, T.; Zaneva, D.; Ivanov, I. J. Photochem. Photobiol., A 2000, 130(1), 7-11; b) Duthie, R. S.; Kalve, I. M.; Samols, S. B.; Hamilton, S.; Livshin, I.; Khot, M.; Nampalli, S.; Kumar, S.; Fuller, C. W. Bioconjugate Chem. 2002, 13(4), 699–706; c) Carreon, J. R.; Stewart, K. M.; Mahon, K. P.; Shin, S.; Kelley, S. O. Bioorg. Med. Chem. Lett. 2007, 17(18), 5182–5185; d) De Rosa, S. C.; Brenchley, J. M.; Roederer, M. Nat. Med. 2003, 9(1), 112–117; e) Awasthi, K.; Nishimura, G. Photochem. Photobiol. Sci. 2011, 10(4), 461-463; f) Roberts, I. G.; Fallon, P.; Kirkham, F. J.; Kirshbom, P. M.; Cooper, C. E.; Elliott, M. J.; Edward, A. D. J. Thorac. Cardiovasc. Surg. 1998, 115(1), 94–98; g) Todor, D.; Nikolai, G.; Aleksey, V.; Karl-Heinz, D.; Yarmoluk, S. M. Dyes Pigments 2006, 70(3), 185-191; h) Meyers, F.; Marder, S. R.; Pierce, B. M.; Bredas, J. L. J. Am. Chem. Soc. 1994, 116(23), 10703–10714; i) Chatterjee, S.; Gottschalk, P.; Davis, P. D.; Schuster, G. B. J. Am. Chem. Soc. 1988, 110(7), 2326–2328; j) Bertolino, C. A.; Ferrari, A. M.; Barolo, C.; Viscardi, G.; Caputo, G.; Coluccia, S. Chem. Phys. 2006, 330(1-2), 52–59; k) Encinas, C.; Miltsov, S.; Otazo, E.; Rivera, L.; Puyol, M.; Alonso, J. Dyes Pigments 2006, 71(1), 28-36.
3. a) Boto, R. E. F.; Santos, P. F.; Reis, L. V.; Almeida, P. Dyes Pigments 2008, 76(1), 165-172; b) Boto, R. E. F.; Almeida, P.; Queiroz, J. A. Biomed. Chromatogr. 2008, 22(3), 278-288.
Agradecimentos Os autores agradecem o apoio financeiro concedido pela FCT ao projecto “Interações de Afinidade entre Cianinas e Biomoléculas em Processos Cromatográficos” (PTDC/QUI-QUI/100896/2008) e pela bolsa concedida a L.P. Alves (BI-1-PTDC/QUI-QUI/100896/2008).
110
SYNTHESIS OF NEW �-METHYLENE-�-LACTONES LINKED TO FERROCENE DERIVATIVES
J. Albertino Figueiredo,a Carlos Anjo,a Rita Pereira,a M. Isabel Ismael,a Ivânia Cabrita,b Ana C. Fernandesb
a Unidade Materiais Têxteis e Papeleiros, Universidade da Beira Interior, 6201-001 Covilhã,
PORTUGAL; b Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001
Lisboa, PORTUGAL
Ferrocenes are a class of compounds that attracted remarkable attention due to their wide range of interest in material sciences, catalysis and biological assays. The development of structural variations of established drugs by metallocenic organometallic compounds has been made as alternatives of the chemotherapy of drug-resistance in cancer and tropical diseases. The stability, non-toxicity and readily membrane-permeation of the ferrocenyl group, the accessibility of a large variety of derivatives, as well as its favorable electrochemical properties have made ferrocene and its derivatives very suitable for biological applications and for conjugation with biomolecules.1
Synthesis of ferrocene derivatives with α,β-unsaturated �-lactones is a possibility to form new biological compounds. α,β-unsaturated �-lactones occur widely in nature and appear throughout the plant kingdom from the simple metabolites of lichens and fungi to the sesquiterpenes and the steroidal glycosides.2 In this work we present synthesis of α,β-unsaturated �-lactones linked to ferrocene derivatives using the methodology based in Reformatsky-type reaction. Several ferrocene derivatives, with an appropriate carbonyl group, reacted with zinc and ethyl bromomethylacrylate in THF under reflux, affording the corresponding α-methylene-�-lactones in good yields (scheme 1).
Scheme 1
REFERENCES:
1. Rauter, A. P.; Figueiredo, J. A.; Ismael, M.; Canda, T.; Font J.; Figueredo, M.; Tetrahedron: Asymmetry, 2001, 12, 1131–1146.
2. Long, B.; Liang, S.; Xin, D.; Yang, Y.; Xiang, J.; European Journal of Medicinal Chemistry, 2009, 44, 2572–2576.
ACKNOWLEDGMENTS:
The authors acknowledge FCT for financial support through project PTDC/QUI-QUI/102114/2008.
111
Total phenol content in solvents extracts of Lavandula luisieri
João Araújo,1 Fernanda Delgado,2 Jesus Rodilla,1 Arlindo Gomes,1 Lúcia Silva1
1Chemistry Department, Unity of Textile & Paper Materials, University of Beira Interior, 6201-001- Covilhã, Portugal
2 Escola Superior Agrária, Quinta da Sra. de Mércules 6001-099 Castelo Branco, Portugal
Abstract
Lavenders (Lavandula spp.) belong to the family Labiatae (Lamiacae) and have been used either dried or as an essential oil for centuries for a variety of therapeutic and cosmetic purposes. Several therapeutic effects of lavender such as sedative, spasmolytic, antiviral, and antibacterial activities have been reported. The phenolic compounds are a group of antioxidants that fight the free radicals. These compounds can be split in two main groups, phenolic acids and flavonoids. In this study, flowers, leaves and stems of the Lavandula luisieri, were subdued to extractions with three different solvents, hexane, dichloromethane and ethanol. The extractions yields (%) and the total phenol content (mg GAEs/g) were evaluated.
Introduction
Lavandula luisieri (Rozeira) Riv.-Mart. is an aromatic Labiatae endemic to the Iberian Peninsula, common in the South of Portugal and in the Southwest of Spain. [1]. This plant is characteristic of the syntaxon Cisto-Lavanduletae, a class which includes thermo- to supra-Mediterranean dry and semi-arid, sub-humid secondary scrub communities producing aromatic compounds[2]. The extraction of natural substances with antioxidant activity, to replace synthetic food preservatives has gained great importance. Extensive research has been dedicated to identification of antioxidant compounds of natural sources, and the antioxidant activity of many plants has been investigated. All plants produce an amazing diversity of secondary metabolites. One of the most important groups of these metabolites are phenolic compounds. Phenolics are characterized by at least one aromatic ring (C6) bearing one or more hydroxyl groups. Phenolic compounds and acids are plant metabolites widely spread throughout the plant kingdom. Recent interest in phenolic acids stems from their potential protective role, through ingestion of fruits and vegetables, against oxidative damage diseases (coronary heart disease, stroke, and cancers). Phenolic compounds are essential
for the growth and reproduction of plants, and are produced as a response for defending injured plants against pathogens. The importance of antioxidant activities of phenolic compounds and their possible usage in processed foods as a natural antioxidant have reached a new high in recent years [3]. This work consists in the study of these compounds in different parts of Lavandula luisieri using solvent extraction.
Materials and Methods
Experimental general proceedings
All the solvents and used reagents were analytically pure. The reagent Folin-Ciocalteu was acquired from Sigma life science, the gallic acid from Acros Organics. The measures of absorption were done using spectrophotometer UV-Vis Evolution 160.
Plant material
Lavandula luisieri was collected in Penamacor and then cultivated in Escola Superior Agrária de Castelo Branco. For this work we use the cultivated plant. The material plant was separated in flowers, leaves and stems. Then it was dry and ground before the extraction.
Solvent extraction
The sequential extraction was made with solvents of growing polarity with the use of a Soxhlet. Hexane, dichloromethane and ethanol, were the solvents chosen. The extractions were made duplicated with samples of 20g of leaves and stems, and 17g of flowers each. The solutions were cooled and then concentrated at room temperature under vacuum.
Total phenols content
The total phenols content was determined according to the Folin-Ciocalteu method. The concentration of total phenols in extracts was measured by UV spectrophotometry, based on a colorimetric oxidation/reduction reaction.
112
The oxidizing agent used is Folin-Ciocalteu reagent. To 0.05 ml of diluted extract, 0.45 ml of water and 2.5 ml of Folin-Ciocalteu reagent (Sigma, diluted 10 times with water) was added. In a 5 min time interval, 2ml of Na2CO3 (75 g/l) was added. For a control sample, 0.05 ml of distilled water was used. Leave in water at 30 ºC for 1.5 h with intermittent agitation. Gallic acid standard solutions were used for constructing the calibration curve. The absorbance was measured at 765 nm. The results were expressed in mg of gallic acid per g of dry plant material.
Results and Discussion
The yields of the different extractions are present in table 1. Since it is possible to conclude, the stems are the part of the plant in which less yield of extraction was obtained. On the other hand, very good extraction levels are achieved in flowers and leaves, using hexane and dichloromethane. The hexane extraction of the flowers was the one that present biggest yield.
Table 1 - Yields of extractions and total phenolic content (expressed as mg Gallic acid/g of Dry Weight).
The calibration curve of gallic acid was obtained using different values of concentration (1000-50 mg/ml) and has a R2=0,9973. Based in table 1, our results suggest that the leaves are the part of Lavandula luisieri that has greatest phenol content, followed by the flowers and finally the stems. The phenol content was a lot higher in the ethanolic extraction as expected, even having the lowest yield of extraction. It can be notice that as we increase the polarity of the solvent, the phenol content grows as well.
Conclusions
A lot of different characteristics has been attributed to this plant that continuous to justify the growing interest of the scientific community. As here reported, the Lavandula luisieri is a easy, non-expensive, rich fountain in phenolic compounds. There´s still a lot to know about all the features of this plant, about their compounds and biological activity.
References 1. J. Sanz, A.C. Soria, M.C. García-Vallejo., Analysis of volatile components of Lavandula luisieri L. by direct thermal desorption gas chromatography mass spectrometry. J. of Chromatography A, 1024, 139 146, 2004. 2. A. González-Coloma, F. Delgado, J. M. Rodilla, L. Silva, J. Sanz, Jesus B. Chemical and biological profiles of Lavandula luisieri essential oils from western Iberia Peninsula populations. Biochemical Systematics and Ecology, 39, 1 8, 2011. 3. A. Michalak., Phenolic Compounds and Their Antioxidant Activity in Plants Growing under Heavy Metal Stress., Polish J. of Environ. Stud. 15(4), 523-530, 2006.
Acknowledgements
To the Unity of Textile & Paper Materials of Beira Interior University for making this work possible.
Concentration (mg / ml)
ExtractionYields (%)
Phenol Content(mg/ g of dry weight)
Hexane Flowers 124,0 9,8 46,1 Leaves 108,0 7,6 63,7 Stems 33,0 1,5 15,1
Dicloromethane Flowers 106,0 6,8 62,0 Leaves 119,0 7,6 71,4 Stems 20,0 1,2 31,8
Ethanol Flowers 41,0 2,7 132,6
Leaves 57,0 3,2 177,8
Stems 17,0 1,6 130,2
113
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114
Synthesis, characterization and antioxidant activity of Thio-imidate N-oxides (TIO) sugars
M. Domingues1, M.I. Ismael1, J. A. Figueiredo2, M. Schuler2, P. Rollin2, A. Tatibouët2
1Departamento de Química, Unidade I D Materiais Têxteis e Papeleiros, Universidade da Beira Interior
Av. Marquês de Ávila e Bolama, 6200-001 Covilhã, Portugal; 2 ICOA - UMR 6005, Université d’Orléans, BP 6759, F-45067 Orléans Cedex 2 (France)
http://www.univ-orleans.fr/icoa/synthese.
Many natural products contain sugars in structurally modified forms. The combinations of
these modifications produce antibiotics, anti-tumor and antioxidant compounds. The
synthesis and biosynthesis of these sugars are currently areas of active investigation1. The aim
of our project is to develop innovative carbohydrate templates bearing unexpected
thiofunctions for biological applications.
The chemical target of this work is the preparation of an unusual thio-imidate N-oxide
function, its characterization and antioxidant activities. On a carbohydrate template, two
pathways were used to access the thiofuntion. The first method: D-ribose was converted to
an aldoxime in three steps. After protection of the aldoxime, the thiohydroximate function
was efficiently introduced. Then de-O-silylation of the thiohydroximate followed by a
specifically designed ring-closure using the Mitsunobu2 procedure afforded the expected
thioimidate N-oxide3. The second method started also with D-ribose which was converted in
the deoxy-iodo-sugar4 in two steps. Ring-fragmentation originated an unsaturated aldehyde,
after its reduction, the compound was transformed into an O-silyl ether.
The antioxidant activities were determined by the DPPH method5. The aldoxime 3, deoxy-
iodine-sugar 10 and the silyl ether 13 showed antioxidant activities.
References [1] P. Collins; R. Ferrier; “Monosaccharides: their chemistry and their roles in natural products”; John
Wiley � Sons; 1st edition; 1995.
[2] Mitsunobu, O.; Bull. Chem. Soc. Jpn., 1967, 40, 2380.
[3] Iori, R. ; Barillari, J.; Gallienne, E. ; Bilardo, C. ; Tatibouët, A. ; Rollin, P. ; Tetrahedron Lett.,
2009, 50, 3302.
[4] Garegg, P.J.; Samuelsson,B.; J. Chem. Soc., Perkin Trans. 1, 1980, 2866-2869.
[5] Sousa, C.; Silva, H.; Vieira-Jr, G.; Ayres, M.; Costa, C.; Araújo, D.; Cavalcante, L.; Barros, E.;
Araújo, P.; Brandão, M.; Chaves, M.; Quim. Nova, 2007, 30, 351-355.
O
N+
S
O
O
Chiral
D-Ribose .....
115
Synthesis of monolithics supports for affinity chromatography
N. Esteves, C. Canário, P. Almeida, M. J. Nunes
Departamento de Química e Unidade de Materiais Têxteis e Papeleiros, Universidade da Beira Interior, 6200-001 Covilhã, Portugal
Abstract Monoliths are a new class of stationary phases. A monolith is a single piece of porous material. Its pores are highly interconnected, forming a network of channels, where the sample is transported via convection, resulting in a very fast transfer between mobile and stationary phase. As a consequence, even large molecules like proteins can be separated in an extremely short time at room temperature. Monoliths can be used in different types of chromatography, namely the affinity chromatography. This work aimed to optimize the synthesis conditions of the monolith resulting from the polymerization of glycidyl methacrylate and ethylene dimethacrylate in order to compare their performance against commercial monoliths for purification of biomolecules, using aminocyanines as ligands. For this purpose, poly(glycidylmethacrylate-co-ethylenedimethacrylate monoliths have been synthesized in different conditions (temperature, initiator, composition of porogenic solvent and concentration of crosslinking monomer). The preliminary results showed that the conditions of polymerization are crucial to the achievement of certain porosity.
Introduction Affinity chromatography (AC) is the most powerful tool for the separation, purification and recovery of proteins and enzymes. Dye ligand AC is widely used because it is commercially available, inexpensive, stable and can easily be immobilized especially on matrices bearing hydroxyl groups. [1] Monoliths are a new class of stationary phases and can be used in different types of chromatography, namely the AC. They are becoming very attractive stationary phases due to their advantageous hydrodynamic characteristics. The main difference in comparison to conventional particle beds is in their structure. These consist of a single piece of a continuous structure. The pores are highly interconnected, forming a network of channels, which makes them highly porous. An advantage of monolithic supports is their good resolution turned out to be flow-independent, low resistance to flow, large surface area, high permeability and high concentration of functional groups. Monolithic supports have become the subject of extensive study in the past years. Their preparation is another advantage. In contrast to particle preparation, where commonly particle size classification is required after polymerization is completed, monoliths are prepared with a bulk polymerization and their structure is defined already by
monomer composition and polymerization temperature without further processing [2]. The monoliths can be obtained from different types of monomers and polymerization reactions. Glycidyl methacrylate-based monoliths were introduced in 1990. They were polymerized from glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA) in the presence of porogens and an initiator. The polymer is chemically and mechanically very stable and contains epoxy groups that can be further modified.The polymerization mixture involves a monomer, a crosslinking agent, an inert solvent or mixture of solvents, which act as porogenic agents, and a free radical initiator. The preparation of macroporous polymer beads is generally achieved as a result of the phase separation which occurs during the polymerization of a monomer mixture containing appropriate amounts of both a crosslinking monomer and a porogenic solvent. The porous properties of such particulate resins can be controlled by many variables. The most important ones are generally thought to be the concentration of crosslinking monomer in the monomer mixture, the type and percentage of porogenic solvent present in the polymerizing system and the temperature reaction [3]. Although the use of monoliths is already widespread for the purification of biomolecules, such as the use of cyanine ligands are at an early stage. Thus, the synthesis of aminocyanines that would later be used as ligands was also one of the objectives of this work. In order to find monoliths that meet the above conditions, we carried out a study where the composition porogenic solvents, time and type of initiator was varied.
Materials and Methods Cyanines dyes: The aminocyanine dye was obtained by reduction of the corresponding nitrocyanine, using hydrazine hydrate in presence of Raney nickel, in ethylene glycol. [4] Monoliths: The tubular molds were sealed at one end with rubber septa fitted over a piece of polyethylene film, filled with the mixture. The initiator, benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN) (1 wt % with respect to monomers) was dissolved in 3-4 vol parts of a mixture consisting of glycidyl methacrylate (60%) and ethylene dimethacrylate (40%). The porogenic solvents (7-6 vol parts), mixtures of cyclohexanol (50-100%) with dodecanol (50-0%) were admixed slowly to the monomers. The polymerization mixtures were sonicated for 20 min, purged with nitrogen for 15 min in order to remove oxygen, kept in nitrogen atmosphere and placed in a
116
vertical position into a water bath. The polymerization was allowed to proceed for 24 or 48 h at 50-85 °C. The seals were removed, the tube was provided with fittings, attached to the high-pressure pump, and ethanol was pumped through the column at a flow depending on the flow resistance of the rod to remove the porogenic solvents and any other soluble compounds that remained in the polymer rod after the polymerization was completed.
Results and Discussion Monomethinecyanines were readily prepared through the classical route involving the condensation of the corresponding heterocyclic quaternary salts, one with a methyl and the other with a thiomethyl group at the position 2, in dry pyridine. The aminocyanine dye was obtained by reduction of the corresponding nitrocyanine,
using hydrazine in presence of Raney nickel, in ethylene glycol. The morphology of the monoliths is closely related to the properties of the pores. This is a direct consequence of the composition of the porogenic solvents, the percentage of crosslinking monomer, a ratio between monomers and porogenic agents and temperature. When a higher content of poor solvent is used, such as dodecanol, larger pores are obtained. The temperature may have an opposite effect, but normally, the higher the polymerization temperature, the smaller the pores. For the different conditions used, the permeability of the monoliths is practically the same, whether using AIBN or BPO as radical initiator. We have already started the studies of the immobilization of the aminocyanine dye onto the monoliths synthesized, but the work is already in a preliminary step.
Table 1 Experimental conditons for the synthesis of the monoliths
%(Cyclohexanol/
Dodecanol) Temp.
(ºC) Time (h) Iniciator Observations
Monolith 1 80/20 85 48 BPO Not permeable, even under pressure
Monolith 2 80/20 70 48 BPO Not permeable, even under pressure
Monolith 3 100/0 50 48 AIBN Not permeable, even under pressure
Monolith 4 100/0 50 24 BPO Not permeable, even under pressure
Monolith 5 100/0 50 48 BPO Not permeable, even under pressure
Monolith 6 80/20 50 48 AIBN Permeable under pressure
Monolith 7 80/20 50 24 BPO Permeable under pressure
Monolith 8 80/20 50 48 BPO Permeable under pressure
Monolith 9 70/30 50 48 AIBN Permeable under pressure
Monolith 10 70/30 50 24 BPO Permeable under pressure
Monolith 11 70/30 50 48 BPO Permeable under pressure
Monolith 12 60/40 50 48 AIBN Permeable
Monolith 13 60/40 50 24 BPO Permeable
Monolith 14 60/40 50 48 BPO Permeable
Monolith 15 50/50 50 48 AIBN Permeable
Monolith 16 50/50 50 48 BPO Permeable
% (GMA/EDMA) =60/40 for all the experiments
References
1. Viklund, C., Svec, F., and Fréchet, J.M.J. Chem Mater, 8, 744, 1996, The Netherlands, 2001.
2. Hahn, R., Podgornik, A.,Schallaun, E., and Jungbauer, A. Anal. Chem., 73, 5126, 2001.
3. Hrobárik, P., Sigmundová, I., and Zahradnik, P. Synthesis, 4, 600, 2005.
4. Pardal, A.C., Nunes, M.J., Gama, A.M., Queiroz, J.A., and Almeida P. Coloration Technology,118, 95, 2002.
Acknowledgements
We are grateful to Fundação para a Ciência e a Tecnologia, Portugal, POCTI and FEDER, for the funding
-Affinity Chromatography (POCTI/2002/QUI/ 44776).
117
Anodic oxidation of Acid Red 88 on a BDD electrode A.D. Fonseca*, P. Luz, L. Ciríaco, M.J. Pacheco, A. Lopes
UMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal Abstract The aim of this work was the study of the influence of applied current density on the conversion and / or mineralization of a mono azo dye, Acid Red 88 by anodic oxidation, using as anode a BDD electrode. Electrodegradation tests were performed on a batch system, with stirring, in an electrochemical cell containing a BDD electrode as anode and a stainless steel plate as cathode. Sodium sulfate aqueous solutions were used as support electrolyte. Samples were collected regularly during tests and Chemical Oxygen Demand and Total Organic Carbon were determined, as well as UV-Visible absorption spectra. After 4 hours assay, COD and TOC removals up to 92% and 87% were obtained, respectively, at the applied current density of 30 mA cm-2. At this applied current density, absorbance removals were almost complete after 3 h assay. The results also show that mineralization efficiency decreases with current density. Introduction Nowadays, the occurrence of undesired accumulation in the aquatic environment of persistent organic pollutants, such as dyes, pharmaceuticals, aromatic amines has been an emerging global concern. Most of these organic compounds are toxic and with potential carcinogenic properties [1]. In particular, dyes and aromatic amine have been recognized as high priority pollutants by the United States Environmental Protection Agency [2]. Also, European Community made a list of 22 dangerous aromatic amines and prohibited the use of azo dyes which, by reductive cleavage of one or more azo groups, may release one or more of those aromatic amines, in detectable concentrations, i.e., above 30 mg L-1 in the finished articles or in the dyed parts thereof and may not be used in textile and leather articles which may come into direct and prolonged contact with the human skin or oral cavity (CONSLEG: 1976L0769 — 16/03/2004). The aromatic sulfonated amines, resultant from the partial degradation of azo dyes, are also very dangerous pollutants, since they are very soluble in water and many of them resist to microbial degradation [3]. In order to solve this problem, the potential of the electrochemical processes in combating persistent organic pollutants has been under intense study in the last years. Thus, it has been found that the electrochemical technology can be a versatile and effective pollution control technique, modifying, degrading or mineralizing organic compounds, through a process where the only reagent involved is the electron, which is a "clean reagent". Another reason that makes these methods widely used is because the combustion can be complete, i.e., the organic pollutant can be completely oxidized, forming CO2, H2O and inorganic ions [4,5].
In fact, electrochemical techniques can be a promising option to solve many environmental problems, especially in the case of the anodic oxidation performed with boron-doped diamond (BDD) anodes [6-8], even for the degradation of azo dyes [9]. The aim of this work was to study the influence of the applied current density on the conversion/combustion of an azo dye, Acid Red 88, by anodic oxidation, using as anode a BDD electrode. Materials and Methods The electrochemical assays were run using an electrochemical cell, with a BDD anode of 10 cm2 area, purchased from Admant Technologies/CSEM, Switzerland, and the degradation was carried out in batch mode, for 6 h, at several applied current densities, varying from 2.5 and 30 mA cm-2. A volume of 200 mL of aqueous 0.035 M Na2SO4 solution, containing 50 mg L-1
of the dye Acid Red 88 (Figure 1), purchased from Aldrich, was used in each assay. The current was imposed by a laboratory power supply GW, model GPS-3O3OD. All the electrochemical assays were performed in galvanostatic mode and at controlled temperature of 30ºC. The degradation tests were monitored using the following techniques: UV-Visible absorption spectrophotometry, with absorbances being measured from 200 to 800 nm, using a Shimatzu 1200 UV/VIS spectrophotometer; Chemical Oxygen Demand (COD) determinations, using the closed reflux dichromate titrimetric method [10]; and Total Organic Carbon (TOC) determinations, performed in a Shimadzu TOC-VCPH apparatus.
Na
OH
N
N
S
O
O
O
Figure 1. Chemical structure of the dye Acid Red 88. Results and Discussion Figure 2 presents the experimental relative COD removal as a function of the assays’ duration, for the different applied current densities tested. As can be observed, COD removals are very high after 6 h assay and they increases with the applied current. The samples collected during the assays performed were also analyzed for the total organic carbon content (Figure 3). There is a good similarity between the results obtained for COD and TOC analysis. In general, this is the typical behavior of anodic oxidations with high degree of mineralization.
118
Figure 2. COD relative removal vs time for the electrochemical degradation of the AR88 under different applied current densities. Electrolyte: Na2SO4 (0.035 M); T=30ºC.
Figure 3. TOC relative removal vs time for the electrochemical degradation of the AR88 under different applied current densities. Electrolyte: Na2SO4 (0.035 M); t=30ºC. The color removal during the electrodegradation assays was also monitored. The UV-Visible spectra of the AR 88 (data not shown) presents one band in the visible region at about 495 nm, due to the conjugated system of the naphtalenic rings with the azo bond, and bands at the UV region, with a maximum at 288 nm, due to the absorption of the aromatic structures. In Figure 4 the absorbance decay with time, measured at two characteristic wavelengths, for the assays performed at the different applied current densities is presented. We can observe a higher decay in the absorbance measured at 495 nm, meaning that azo bond is more easily broken than the aromatic structures. However, except for the assay performed at 2.5 mA cm-2, after 4 h assay, the behaviors at both wavelengths are similar which means that mineralization of the AR88 is high. Conclusions The electrochemical degradation of the dye AR88 was carried out at different current densities, showing that an increase in current leads to a faster removal of the organic load. The increasing of the applied current density results in a faster color removal and mineralization due to an increase in the quantity of the hydroxyl radicals formed.
The good results obtained in the degradation of the dye show that electrochemical techniques are a promising method to treat real effluents, especially when biological treatments are not an option.
Figure 4. Relative absorbance decay measured at the λmax of two different characteristic bands: 495 nm (a), and 288 nm (b).
References 1. Pinheiro, H.M., Touraud, E., and Thomas, O., Dyes
Pigments, 61, 121-13, 2004. 2. EPA OPPT Chemical Fact Sheets, Aniline Fact Sheet;
Support Document (CAS Nº 62-53-3), December 1994. 3. Alonso, M.C., and Barceló, D., Analytical Chimica Acta,
400, 211, 1999. 4. Bertazzoli, R., Pelegrini, R., Química Nova, 25, 477-482,
2002. 5. Mohan, N., Balasubramanian, N., Basha, C. A., Journal of
Hazardous Materials, 147, 644-651, 2007. 6. Panizza, M., Brillas, E., Comninellis, Ch., Journal of
Environmental Management, 18, 139-153, 2008. 7. Panizza, M., Cerisola, G., Electrochimica Acta, 51, 191-
199, 2005. 8. Panizza, M., Cerisola, G., Chemical Reviews, 109, 6541-
6569, 2009. 9. Fernandes, A., Morão, A., Magrinho, M., Lopes, A.,
Gonçalves, I., Dyes and Pigments, 61, 287-296, 2004. 10. Eaton, A., Clesceri, L., Greenberg, A., Standard Methods
for Examination of Water and Wastewater. APHA, AWWA, WEF, 21st Ed., Washington, 2005.
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Aplicação do catalisador Cu-TiO2 na fotodegradação de uma amina aromática J. Matos, A. Santos, M. Magrinho, J. Lucas
UMTP, Universidade da Beira Interior, 6201-001 Covilhã, Portugal Resumo Este estudo analisa a fotodegradação sob luz solar do ácido 4-aminobenzenesulfónico, usando-se como nanocatalisadores amostras de Cu-TiO2 preparadas por via húmida e caracterizadas por Microscopia Eletrónica de Varrimento, Espetroscopia por Energia Dispersiva de raios-X e Difração de raios-X. A decomposição da amina foi acompanhada por espetroscopia de UV-Visível e determinações de Carbono Orgânico Total. O catalisador mostrou uma elevada eficiência no processo deste corante, indicando desta forma que a dopagem do dióxido de titânio com cobre é um caminho viável para a criação de novos fotocatalisadores. Palavras chave: TiO2, fotodegradação, amina aromática Introdução Os corantes industriais, em particular, os corantes azo causam grande apreensão ambiental devido aos produtos tóxicos da sua degradação e à baixa taxa de remoção durante as fases aeróbicas de tratamento1-3. Os Processos de Oxidação Avançada (POA) são alguns dos poucos sistemas reacionais que levam à completa degradação destas aminas4,5. Entre estes, a fotocatálise heterogénea é um método muito eficaz para a oxidação completa destes poluentes orgânicos recalcitrantes6-9. Basicamente, este método assenta na produção de radicais livres altamente reativos capazes de decompor grupos aromáticos. O catalisador é irradiado com energia igual ou superior ao seu hiato energético, os eletrões são promovidos da banda de valência para a banda de condução, resultando em pares eletrão-lacuna catiónica. A lacuna na banda de valência possui potencial suficiente para gerar radicais hidroxilo e oxidar as espécies orgânicas à superfície das partículas, enquanto o eletrão na banda de condução reduz o oxigénio molecular e substratos orgânicos. Métodos As nanopartículas de TiO2, foram dispersas em sulfato de cobre (II) sendo a dispersão continuamente agitada num oscilador orbital a 25 º C. Terminada a reação, o material resultante foi lavado e seco a 110 °C por 24 horas. Os materiais obtidos foram moídos durante 20 min e aquecidos a 400 ºC durante 5 horas. A análise dos fotocatalisadores foi realizada por DRX, MEV e EDX. As experiências sob irradiação da luz solar foram realizadas com suspensões aquosas (500 mL; pH=3,4; catalisador 2 g/L; ácido sulfanílico 0,050 g/L) contidas em reatores abertos ao ar, com 13 cm de diâmetro externo. Os ensaios foram realizados em junho,
sob o céu limpo, entre as 10 horas e as 16 horas, com flutuações de intensidade solar mínima. A evaporação da água foi controlada gravimétricamente e compensada. Realizaram-se ensaios semelhantes em dias diferentes, sendo considerados os valores médios das medidas de concentração da amina. As amostras foram colhidas ao longo do tempo, centrifugadas a 4000 rpm por 30 minutos e filtradas em membranas de ultrafiltração. A degradação do ácido sulfanílico foi seguida por espetroscopia de UV-Vis e determinações de COT. Resultados e Discussão Os resultados de EDX mostram que a máxima percentagem atómica de cobre na rede do catalisador foi de 0,7 %. Não foram detetadas outras fases cristalinas correspondentes aos óxidos de cobre, nem se verificaram mudanças significativas nos parâmetros de rede. A Figura 1 mostra a superfície das amostras de dióxido de titânio dopado e não dopado, não revelando diferenças morfológicas significativas.
Figura 1: imagem MEV de TiO2 não dopado (A) e dopado com cobre (B)
(A)
(B)
120
A utilização do catalisador Cu-TiO2 permite a degradação da amina com uma eficiência de 50% relativamente ao processo com o TiO2 não dopado. A figura 2 mostra uma redução do tempo de degradação de 6 para 3 horas. A velocidade da decomposição segue uma cinética de 1ª ordem e depende exclusivamente da concentração da amina e das interações entre a superfície das partículas do catalisador. Terminado o processo efetuaram-se determinações de COT para verificar a existência de carbono orgânico, detetando-se apenas em quantidades residuais. Estas observações mostraram a mineralização da amina.
Figura 2: desaparecimento da amina sob radiação solar com CuxTi1-xO2
Conclusões O método de impregnação via húmida para impregnação de TiO2 com iões Cu2+ originou um catalisador com boa homogeneidade e granulometria na ordem dos nanómetros. O ácido sulfanílico foi completamente mineralizado por nanopartículas de TiO2 sob luz solar em seis horas, mas observou-se um aumento de velocidade desta degradação de aproximadamente 50% pela dopagem destes materiais com iões cobre (II). A introdução dos iões cobre na rede do TiO2 anatase permite uma utilização mais eficiente da radiação disponível para a degradação da amina.
Referências
1. Garcia, J.C.; Simionato, J.I.; Almeida, V.C.; Palácio, S.M.; Rossi, F.L.; Schneider, M.V.; Souza, N.E.; J Brazil Chem Soc. 2009, 1.
2. Pielesz, A.; Baronowska, I.; Rybakt, A.; Wlochowicz, A.; Ecotox Environ Safe 2002, 53, 42.
3. Moraes, S.G.; Freire, R.S.; Durán, N.; Chemosphere 2000, 40, 369.
4. Costa, M.C.;, Santos, A.B.; Mota F.S.B., Mendonça, G.L.F.; Nascimento, R.F.; Quim. Nova 2010, 33, 1514.
5. Santos, P.K.;Fernandes, K.C.; Faria, L.A.; Freitas, A.C.; Leonardo Morais da Silva, L.M.; Quim. Nova 2011, 34, 1315.
6. Al-Kdasi. A.; Idris, A.; Saed, K.; Guan, C.T.; Global Nest: the Int. J. 2005, 6, 222.
7. Rajeshwara, K.; Osugi, M.E.; Chanmanee, W.; J. Photoch. Photobio. C 2008, 9, 171.
8. Rauf, M.A.; Ashraf, S.S.; Chem Eng J. 2009, 151, 10.
9. Litter, M.A.; Appl Catal B-Environ 1999, 23, 89. Agradecimentos Centro de Ótica da Universidade da Beira Interior Departamento de Ciência e Tecnologia Têxteis
121
Steady and Unsteady Bifurcation Flows of Non-Newtonian Inelastic Fluids H. M. Matos 1, P. J. Oliveira 1
1Departamento de Engenharia Electromecânica, Unidade de Materiais Têxteis e Papeleiros, Universidade da Beira Interior, Rua Marques D’Ávila e Bolama, 6200-001 Covilhã, Portugal
Abstract Steady and unsteady laminar flows in a planar 2D T-junction are studied numerically for non Newtonian inelastic fluids whose rheological characteristics are similar to those of blood. These computational fluid dynamics simulations scan variations of inertia, flow rate ratio and shear thinning, with the objective of determining the sizes of the recirculating eddies formed near the bifurcation and the resulting distribution of the shear stress fields. In hemodynamics such flow complexities are related to the genesis and development of vascular diseases, like the formation of atherosclerotic plaques and thrombi. To represent the decay of viscosity with shear rate we apply the Carreau-Yasuda equation. In many comparisons of the present parametric study it was require that the level of inertia is approximately the same when the power law index was variable, which implies a consistent definition of the Reynolds number. Introduction Bifurcation flows are important in many engineering and bio-engineering applications. In engineering applications, bifurcations are commonly used in liquid distribution systems. However when the working fluid is composed by a mixture of a number of fluids and other materials like it may be found in dyeing processes in the textile industry or in the production process of paper, phase distribution in the main and the branch ducts is inevitably different, affecting the flow control and processing facilities downstream. In some situations, like in the petroleum industries, this phenomenon is advantageous and is used to accomplish the first stage of oil and gas phase separation, with attending improvement in the efficiency of the transport system [1]. Bio engineering applications are well illustrated by the hemodynamical circulatory system, in which blood flows along successive levels of arterial bifurcations producing highly complex flow patterns that promote the appearance of regions with flow separation and recirculation, which are well correlated with to the emergence and development of vascular diseases [2, 3]. Due to the highly complex flow, the endothelium wall is more easily damaged and this facilitates the macromolecules to migrate into the arterial wall, leading finally to the atherosclerotic plaque formation [4]. The interaction between blood flow and the artery wall, through the action of the fluid shear stress, is known to be extremely relevant. Blood is a complex fluid that consists in a suspension of platelets, leucocytes and erythrocytes in plasma [5], and possesses therefore non-Newtonian properties. Blood exhibits a shear-thinning viscosity, is thixotropic and
viscoelastic [6]. Among the various non-Newtonian blood properties we concern our attention in shear thinning effects. These computational fluid dynamics simulations scan variation of inertia, flow rate ratio and shear thinning, on steady and unsteady laminar flows in a planar 2D T-junction. Inertia effects were varied through the Reynolds number (
1Re u H ), from 50 to 1000. The shear-
thinning viscosity follows the Carreau-Yasuda model in which the power law exponent was changed according to the intensity of viscosity variation. Finally the flow rate ratio (
3 1Q Q ) varied from 0.1 to 0.9.
Numerical Simulation
Differential Equations
For the simulation of incompressible and isothermal, laminar, time-dependent flows, the equations to be solved are those expressing conservation of mass (Eq. 1) and linear momentum (Eq. 2):
0u (1)
pt
uuu (2)
Where u is the velocity, p is the pressure and is the
fluid density. The stress tensor in Eq. (2) is specified by a rheological constitutive model which depends on whether the fluid is Newtonian or non-Newtonian (inelastic). For Newtonian fluids the stress tensor follows the Newton law for viscosity expressing a linear and explicit stress-strain rate relationship ( 2 D ) where D is the rate-
of-strain tensor, represents the fluid viscosity and is
the shear rate tensor. For non-Newtonian inelastic fluids (Generalized Newtonian Fluids) the Carreau–Yasuda model [7] (Eq. 3) is followed to represent the viscosity variation with shear rate.
1
0 1n aa (3)
In Eq. (3) 0 and are the zero and infinite shear rate
viscosities, is a constant time and n is the power law exponent. The magnitude of these parameters is obtained from [8].
Numerical Method
We apply the finite-volume method on non-staggered meshes in which all variables are stored at the centre of cells forming the mesh [9]. The coupling between the velocity and stress fields employs the method of Oliveira et al. [10] later modified by Matos, et al. [11]. Spatial discretisation of the convective terms is accomplished with the high resolution scheme CUBISTA [12] and
122
temporal discretisation of the unsteady term follows the three time level scheme [13]. The pressure-correction method employed is based on the SIMPLEC algorithm.
Geometry and Computational Mesh
The simulations were carried out in a 2D T-shaped geometry (Fig. 1) having a constant cross section area with height H . The flow conditions were similar to those of Miranda et al. [6]. At the inlet a Dirichlet boundary conditions were used, by imposing a parabolic velocity profile for the steady state flows, while for transient flows the velocity profile is pulsating and generated by a sinusoidal pressure gradient:
0 cos( )S
dpK K t
dx (6)
Here SK is the magnitude of the steady pressure
gradient and 0K is the magnitude of the oscillating
pressure gradient (0 2.585SK K ). The Womersley
number is 1 2( ( ) ) 4.864H .
At the outlets, Neumann boundary conditions were imposed. The other boundary planes are solid walls where the no slip boundary condition was imposed. The mesh is formed by 12800 control and the study of mesh refinement can be found in Matos et al. [11]. For unsteady flows the time step is 35 10 .
x
y
H
XS
Q1 Q2
Q3
Ytot = 21 H
Xtot = 26 H
H
XL XR
YL
YR
YS
H
Figure 1 – Schematic representation of the simulation geometry.
Definition of effective Reynolds number
For Newtonian fluids the viscosity does not change and the Reynolds number is varied through the fluid velocity at the inlet. On the other hand for non Newtonian fluids, viscosity depends on the shear rate (Eq. 7) which affects the Reynolds number calculation and produces a hidden variation of the Reynolds number in these cases when Newtonian conditions are used.
1 1 with / 2
u H uRe
H (7)
In order to maintain the effective Reynolds number constant for all cases it is necessary to adopt a modification in the calculation of Re . For this purpose in
this work we adopted an iterative procedure to determine the mean velocity that the flow must have at inlet, for an specified Reynolds number, when the corresponding viscosity of the fluid is based on the Carreau-Yasuda model, for different power law exponents, through the expression:
1
1 0 11 2
na aRe
u u HH
(8)
During this text we adopt by default the consistent Reynolds number obtained through the iterative process defined by Eq. (8). In some results the number of Reynolds was obtained by the two methods: we refer to the “Newtonian Reynolds method” or ReNewt
when the
Newtonian viscosity is used, and to “Modified Reynolds method” or ReMod
, when the viscosity is obtained from
the Carreau-Yasuda model and defined in a consistent way.
Results and Discussion The results presented are normalised, using as length scale the channels height H , as velocity scale the average velocity of the inlet flow (
1u ), as stress scale the value of
the wall shear stress at inlet under fully-developed steady flow (
1 16 /w u H ), and the ratio 2 / for time scale.
In the stress scale the characteristic viscosity depends on fluid; for Newtonian and GNF fluids with the Newtonian Reynolds method, the Newtonian viscosity is used , while for GNF fluids with the Modified Reynolds method the viscosity is obtained from the Carreau-Yasuda model at
1 1 0.5u H .
The principal dependent variables in these study are the recirculation lengths of both eddied created in the main and branch arms (Fig. 1), and the shear stress fields.
Steady flow
Figures 2 and 3 show simultaneously the variation with inertia and flow rate ratio of the horizontal and vertical recirculation lengths. For the horizontal recirculation length we compare the solution obtained with the Newtonian fluid and the non Newtonian fluids (GNF) using both the “Newtonian Reynolds method” and the “Modified Reynolds method”. For the vertical recirculation length only the Modified Reynolds method is presented. Both recirculation lengths
LX
and LY
increase
monotonically with Reynolds number. The eddy in the horizontal branch increases linearly with Reynolds number for flow rate ratios lower than 0.8. The increase in the vertical eddy length is not linear for all extraction ratios due to the interaction of the main vertical recirculation with a new recirculation formed immediately downstream, in the opposite side wall of the secondary branch, which acts as to squeeze the first and delay its growth.
123
Figure 2 – Horizontal recirculation length as a function of
inertia (Re) and extraction ratio ( ) for Newtonian and GNF
fluids.
Figures 2 and 3 also show an increase in length with extraction ratio up to a maximum for 0.6 , while for
higher values of extraction, the size of the eddies decrease. The GNF fluids induce somewhat longer recirculation lengths for both recirculations with the Newtonian Reynolds method define Re such differences in recirculation lengths are artificially accenjtuated, especially for high Reynolds numbers, when the Newtonian and non Newtonian viscosity magnitudes become very different. With the consistent definition of Reynolds number of the modified method the results for Newtonian and GNF fluids are very similar, thus demonstrating that the non-Newtonian shear thinning
effect could be accounted for by the inertial effect when the Reynolds number is obtained in a consistent way.
Figure 3 – Vertical recirculation length as a function of inertia
(Re) and extraction ratio ( ) for the GNF ( ReMod) case.
Figure 4 –Shear stress fields for increasing Reynolds numbers,
at 0.7 ; GNF ( ReMod) case.
Figure 4 presents the evolution of shear stress with inertia for two Reynolds numbers ( Re 100 and Re 300 ). The shear stress magnitude increases with inertia, but there always exist areas of very low shear stress close to the wall in the recirculation zones, while high stresses are generated in the recirculation boundaries, located in the main and the side branches. Such distribution induces high stress gradients and the possibility of shear stress oscillations, in space and time, which may facilitate the inflammatory process and the triggering of an atherosclerotic plaque. In general a comparison of the
XX X X X X X X X X X X X X X X X X X X
Re0 200 400 600 800 1000
0
6
12
18
24=0.1=0.2=0.3=0.4=0.5=0.6=0.7=0.8=0.9
XXL
Newtonian
XX
XX
XX
XX
X X X X
Re0 200 400 600 800 1000
0
6
12
18
24
XL
GNF(Re Newt)
XX X X X X X X X X X X X X X X X X X X
Re0 200 400 600 800 1000
0
6
12
18
24
XL
GNF(Re Mod)
XX
XX
XX X X X X X X X X X X X X X X
Re0 200 400 600 800 1000
0
6
12
18
24
YL
GNF(Re Mod)
1
0.30
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
7 1.056 1.025 14 0.33 02 -0.0061 -0.012
Y
Re=100
0.3 0
1
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
7 1.056 1.025 14 0.33 02 -0.0061 -0.012
Y
Re=300
124
stress fields between the Newtonian and the GNF fluids shows only minor differences with the Newtonian case presenting higher shear stress fields (in modulus) when compared with GNF fluids. Figure 5 shows the evolution of the shear stress field with flow rate ratio. The flow rate ratio promotes a slight increase of maximum shear stress magnitudes (in modulus). It is noted that for low extraction ratios the higher shear stresses are registered along the main duct in the wall layer, while for high extraction ratios they are registered along the secondary branch. The maximum magnitudes occur where layers of fluid having high and low velocities come into contact, which results in increased local shearing of the flow.
Figure 5 –Shear stress fields for increasing extraction ratio, at
Re 100 ; GNF ( ReMod) case.
The influence of shear thinning variation on the two eddy lengths is presented in figure 6 using the Modified
Reynolds method. When the Reynolds number is defined in a consistently way the shear thinning variation promote only slight differences, noting, however, smaller lengths for the Newtonian case ( 1n ).
Figure 6 – Variation of
LX and LY with shear thinning and Re
for GNF fluids with Newtonian Reynolds method and 0.7 .
The influence of shear thinning variation does not promote the existence of large variations in the shear stress field. The shear stress variation is not monotonous, initially the increase in the power law index results in a decrease in modulus of the shear stress magnitudes to minimum values that occur for ( 0.6n ). After that they increase to the maximum shear stress magnitudes that occur for the Newtonian case ( 1n ), as shown by the maximum and minimum values registered in table 1, for different power law index.
Table 1 – Maximum and minimum shear stress for various power law indices.
Power law
index n=0.2 n=0.4 n=0.6 n=0.8 n=1
1MaxXY w 1.22 1.15 1.11 1.18 1.35
1MinXY w -7.25 -6.44 -5.76 -6.20 -8.40
Unsteady flow
All the results presented in this section were obtained at constant inertia, with Re 102 . For unsteady periodic flows the recirculation lengths and shear stresses also change during the cycle. In figure 6 we
0.8
1
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
6 1.025 14 0.83 02 -0.0021 -0.006
Y
=0.2
0.4
1
0
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
6 1.025 14 0.43 02 -0.0021 -0.006
Y
=0.6
0.2
1
0
X-4 -2 0 2 4 6
0
2
4
6 XY
10.80.60.40.20.10
-0.1-0.2-0.4-0.6-0.8-1
Level
6 1.025 14 0.23 02 -0.0021 -0.006
Y
=0.8
X
XX
XX
XX
XX
XX
XX
XX
XX
XX
X
E
EE
EE
EE
EE
EE
EE
EE
EE
EE
E
Re0 200 400 600 800 1000
0
3
6
9
12
n=0.1n=0.2n=0.3n=0.4n=0.5n=0.6n=0.7n=0.8n=0.9n=1.0
X
E
XL
=0.7
GNF(Re Mod)
X
X
XX
XX
XX
X X X X X X X X X X X X
E
EE
EE
EE
EE E E E E E E E E E E E
Re0 200 400 600 800 1000
0
3
6
9
12
YL
=0.7
GNF(Re Mod)
125
present the variation during the cycle of the separation and reattachment points of both recirculations using the GNF fluid ( ReMod
).
This figure shows that the horizontal recirculation is not present during the whole cycle, while the vertical recirculation is always present. However, in the latter case an abrupt reduction in length occurs after the middle of the cycle, which is associated with the breakup of the recirculation into two vortices due to the emergence of a new bubble near the wall. This phenomenon is seen by contrasting the red line (square symbols), which corresponds to the first reattachment point (unique before the division), and the purple line (circular symbols) which corresponds to the second separation point associated with a second recirculation that tends to disappear later in the cycle.
Figure 6 –Variation of the separation and reattachment points
( 0.7 ; 0.3568n ).
The following figures show the influence of shear thinning and extraction ratio upon the recirculation lengths. Figure 7 show the influence of shear thinning variation at constant flow rate ratio ( 0.7 ) and figure 8
shows the influence of flow rate ratio at constant shear thinning intensity ( 0.3568n ). Just as occurred in the case of steady flows (Figure 6) the increase of shear-thinning (decrease of n ) does not afect significantly the results, resulting in slight increase of both
LX and LY recirculation lengths. For the horizontal
recirculation, shear thinning also results in shorter residence times over the cycle, while the vertical recirculation tends to split earlier. The flow rate ratio affects significantly the magnitude of the eddy lengths. The horizontal recirculation length reaches its maximum magnitude near the middle of the cycle and in this part of the cycle it presents a behaviour similar to what was registered for steady state flows. It tends to increase initially with the flow rate ratio, to a maximum that occurs at 0.6 , followed by a decrease
for higher flow rate ratios.
Figure 7 – Variation of recirculation lengths with n .
Figure 8 – Variation of recirculation lengths with extraction
ratio.
t0 0.2 0.4 0.6 0.8 1-1
0
1
2
3
4
5XSXRYS1YR1YS2YR2
XSXRYSYR
=0.7n=0.3568
t0 0.2 0.4 0.6 0.8 1
0
1
2
3
n=0.1n=0.2n=0.3n=0.4n=0.5n=0.6n=0.7n=0.8n=0.9n=1.0
XL
=0.7
t0 0.2 0.4 0.6 0.8 1
0
1
2
3
n=0.1n=0.2n=0.3n=0.4n=0.5n=0.6n=0.7n=0.8n=0.9n=1.0
YL
=0.7
XX X X
X
XX
XX
X X X X X X X X XX
XX
X X XX
t0 0.2 0.4 0.6 0.8 1
0
2
4
6=0.1=0.2=0.3=0.4=0.5=0.6=0.7=0.8=0.9
X
XL
n=0.3568
X X X X X X X X X X X X X X X X X X X X
XX X X X
t0 0.2 0.4 0.6 0.8 1
0
2
4
6=0.1=0.2=0.3=0.4=0.5=0.6=0.7=0.8=0.9
X
YL
n=0.3568
126
For the specific shear thinning intensity here used ( 0.3568n ) there is no recirculation in the main branch for very low flow rate ratios. Increasing the flow rate ratio promotes the appearance of the horizontal recirculation, whose residence time increases monotonically whith extraction ratio. The vertical recirculation length is seen to increase with flow rate ratio, however the rate of increase is reduced as flow rate ratio increases. Furthermore the increase of flow rate ratio also tends to anticipate the division of the vertical recirculation and, for very low flow rate ratios, such division does not occur. The variation of the shear stress field with extraction ratio presents a similar behaviour to what was observed in the case of steady flows: there is a slight increase of the maximum shear stress magnitudes (in modulus) with extraction rate. The location of the maximum shear stresses in modulus tends to occur in the branch where fluid attains larger velocities over the stagnated standing eddy. For unsteady flows shear thinning does not promote significant variations in the shear stress fields like it was observed for steady flows. However in this case the variation is monotonous, with an increase in the the shear stress field as the power law index is raised, as seen by the maximum and minimum values registered in table 2, for different power law index.
Table 2 – Maximum and minimum shear stress for various power law indices.
Power law
index n=0.2 n=0.4 n=0.6 n=0.8 n=1
1MaxXY w 3.99 4.39 5.14 6.60 9.50
1MinXY w -2.61 -2.87 -3.67 -4.12 -5.50
Conclusions Numerical simulations were conducted for flow in a two-dimensional bifurcation with Newtonian and non-Newtonian inelastic fluids. For non-Newtonian flows it was necessary to define the Reynolds number in a consistent way in order to maintain the same inertia as in corresponding Newtonian cases. This was done by including the shear thinning effects on the viscosity used in the Reynolds number calculation. The comparison between Newtonian and non Newtonian fluids show that GNF fluids tend to present longer recirculation lengths in the main and the side branches and reduced shear stress field magnitudes. In steady flows the influence of shear thinning does not result in a monotonous behaviour in the recirculation lengths and shear stress fields variation, while for unsteady flows the behaviour is almost monotonous. An increase of the power law exponent results in a decrease of both recirculation lengths and an increase of the shear stress magnitudes. Flow rate ratio, for both steady and unsteady flows, does not show a monotonous behaviour. In steady state flows,
the recirculation lengths increase with flow rate ratio up to a maximum values at 0.6 , and decrease after that. For
unsteady flows this behaviour is much less pronounced and it is only registered for the horizontal recirculation in the middle of the cycle. In the case of the vertical recirculation, the maximum value is obtained for 0.7
during part of the cycle. For both fluids the maximum magnitudes of shear stresses present a slightly increase with flow rate ratio and the location changes with flow rate ratio variation; high shear stress magnitudes occur in the branch in the shear layer outside the recirculation eddy. References 1. Margaris, P.D., Chem. Eng. Proc., 46(2), 150, 2007. 2. Ku, D., Annu. Rev. Fluid Mech., 29, 399, 1997. 3. Berger, S.A. and Jou, L-D., Annu. Rev. Fluid Mech.,
32, 347, 2000. 4. Crowther, M.A., Hematology, (1), 436, 2005. 5. Anand, M. and Rajagopal, K. R., Int. J. Cardiovasc.
Med. Sci., 4(2), 59, 2004. 6. Miranda A.I.P., Oliveira P.J. and Pinho F.T., Int. J.
Numer. Meth. Fluids, 57(3), 295, 2008. 7. Carreau, P.J. Trans. Soe. Rheol., 16(1), 99, 1972. 8. Banerjee, R.K., Cho, Y.I. and Kensey, K.R., Int. J.
CFD, 9(1), 23, 1997. 9. Oliveira, P.J., Ph.D. Thesis, University of London,
1992. 10. Oliveira, P.J. and Pinho, F.T., Numer. Heat Transfer
B, 35(2), 295, 1999. 11. Matos, H.M.M., Alves, M.A. and Oliveira P.J.,
Numer. Heat Transfer B, 56(5), 351, 2009. 12. Alves, M.A., Oliveira, P.J. and Pinho, F.T., Int. J.
Numer. Meth. Fluids, 41(1), 47, 2003. 13. Oliveira, P.J., J. Non-Newt. Fluid Mech., 101 (1-3),
113, 2001. Acknowledgements H.M. Matos wishes to acknowledge the financial support provided by FCT trough the grant SFRH/BD/18062/2004.
127
Characterization of a leachate from a sanitary intermunicipal landfill. Analysis of the content in metals at several stages of the wastewater treatment plant.
E Mestrinho1, V Ribeiro1, A P Pinto2, M E Lopes1,3 1 Departamento de Química da Universidade de Évora, 2 ICAAM – Instituto Ciências Agrárias e Ambientais Mediterrânicas,
Universidade de Évora. Évora, Portugal, 3 CQE – Centro de Química de Évora
Abstract
In this work the content in seven metals was analysed in samples from a leachate, collected in a sanitary intermunicipal landfill. Samples were collected in three stages of the wastewater treatment plant, just before the biological treatment, just after the biological treatment and from the ultrafiltration permeate. Pb, Cr, Cu, Fe, Mn, Cd, Zn content was determined. Fe was the most abundant of the analysed metals with 22.2 mgL-1 in the samples before the, 41.3 mgL-1 after the biological treatment and 4.0 mgL-1 in the ultrafiltration permeate. Cd content was below detection limit of AAS. Zn, Cu, Cr, Mn and Pb contents are between those limits. The values obtained are in accordance with the range reported in the literature for the analyzed metals. The results obtained suggest that there is a higher concentration of metals in the fraction after the biological treatment, consistent with the fact that there is a recirculation of the ultrafiltration concentrate to this stage. The permeate of ultrafiltration presents the lowest metal content, which indicate an efficiency of the treatment stages so far in metal removal. From the point of view of metal recovery, the best stage to collect samples seem to be after the biological treatment. Introduction Leachates from landfills constitute an environmental problem due to infiltration and contamination of soils and groundwaters. In their composition there are four main groups of pollutants designed in literature as dissolved organic matter, inorganic macrocomponents, xenobiotic organic compounds and heavy metals1,2. Heavy metals are an environmental problem because they tend to accumulate in living organisms and are not biodegradable. On the other hand, some metals have economical interest and it is important to find ways to recover them. So, to remove metals may have both an environmental and an economical motivation3. The design of wastewater treatment plants (WWTP) dedicated to leachates from landfills may have multiple aproaches2. In this study the WWTP performs a treatment that comprises a biological step, followed by an ultrafiltration operation. The ultrafiltration concentrate is recirculated into the biological treatment. In order to analyze the best point where to start an efficient metal recovery procedure in the leachate treatment process, we decided to collect samples from several stages in the leachate treatment process and analyse the content in several metals.
In this work we characterize a leachate from a sanitary intermunicipal landfill concerning seven metals (Pb, Cr, Cu, Fe, Mn, Cd, Zn) in three stages of the wastewater treatment plant: before the biological treatment, after the biological treatment, and from the ultrafiltration permeate.
Materials and Methods 1. Sample collection
The leachate samples in the study were provided by a municipal sanitary landfill and collected in November of 2010. A single sample was collected at each point in containers of 5L. The first sample was collected, just before the biological treatment, the second was collected in the same way just after the biological treatment and a third sample was collected from the permeate of the ultrafiltration. The samples were placed at 4ºC until processing and analysis.
2. Sample treatment All material used in the experimental part was decontaminated using an acid solution with nitric acid and distilled H2O in the ratio of 1:5. The samples studied had a heterogeneous appearance, dark color and high turbidity and so in order to obtain representative samples for analysis, the vessels containing the samples were intensively stirred to homogenize all of your content. The pH was measured in the unit WTW pH Meter 526. To prepare the samples for the analysis was followed a treatment process of acid digestion. Samples were placed in erlenmeyers with differential proportions of aqua regia. Appropriate volumes of aqua regia were added to different samples, since it is important to minimize the volume. The results obtain have shown that it was sufficient a ratio of 1:3 (3 parts of aqua regia for 1 part of sample in volume) in samples “before the biological treatment”, a ratio of 2:3 (3 parts of aqua regia for 2 parts of sample) for samples “after the biological treatment” and finally the ratio of 2:1 (half the volume of the sample in aqua regia was used in this case) for the samples of ultra-filtration permeate. In order to improve the efficiency of sample digestion, the capped samples were subjected to magnetic stirring (Breda Scientific) about 30 min at 40-60ºC making digestion and evaporation more efficient and faster. After this step, the samples were placed in a sand bath at 110±10 °C to total digestion of organic matter, i.e. the final solution it must be clear and transparent. Then, the samples were filtrated for flasks using filter paper, always at the lowest possible volume.
128
1. Analysis by Atomic Absorption Spectroscopy (AAS)
For the metals analysis an atomic absorption spectrometer Perkin-Elmer Model 3100 was used. Standard solutions of each metal were prepared from standard solutions by proper dilution with HNO3 0.01M. Three samples of each stage were measured and corresponding statistical treatment of the values was performed.
Results and Discussion Before any sample collection the pH of each one was measured. The sample “before the biological treatment” had a pH of 8.11, the sample “after the biological treatment” had a pH of 7.80 and the sample “ultrafiltration permeate” had a pH of 6.77. This is in accordance with the fact that before the ultrafiltration, an acidification process occurs. The sample of first stage of the treatment process was more difficult to digest; requiring a larger volume of aqua regia and longer digestion followed by the sample after
biological treatment, and finally, the sample of the permeated of the ultrafiltration, which requires a lower volume of digestion solution and less time for digestion. These are consistent with the content in organic matter of each stage. The results obtained are presented in Table 1. Fe was the most abundant metal. Cr and Zn present also significant values. The metals content is whitin the range of values presented in literature2,5 for leachates of landfills. The stage after the biological treatment is where the leachate presents the highest metal content. This is probably due to the fact that there is a recirculation of the concentrate of the ultrafiltration back to the tanks where the biological treatment occurs. It is a result consistent with the evaluation made in literature,1,6,7
i.e. that metals in leachates are mostly associated with organic molecules and adsorbed on colloidal fractions.
Table 1 – Metals content in each stage of collection of landfill leachate (mg L-1)
Stage of collection Fe Cr Zn Cu Mn Pb Cd
-*
Before biological treatment
22.34 ± 0.03 4.04 ± 0.30 1.76 ± 0.39 0.12 ± 0.00 0.40 ± 0.07 -*
-* After biological
treatment 41.27 ± 0.13 5.48 ± 0.00 2.36 ± 0,10 0.21 ± 0.00 0.66 ± 0.00 0.31 ± 0.10
ultra-filtration Permeate
4.01 ± 0.18 0.79 ± 0.00 0.52 ± 0,03 0.01 ± 0.00 0.10 ± 0.01 0.09 ± 0.00 -*
* values obtained are not within the limit of detection.
Conclusions
The studied leachate presents low concentrations on the metals studied, namely on the heavy metals Pb and Cd. The leachate samples just after the biological treatment present the highest metal content. This may be due to the recirculation of the ultrafiltration concentrate back to the lagoon where the biological treatment is done. This study characterized the leachate from a intermunicipal landfill at several stages f the WWTP showing hat the content in the analysed metals is within the ranges described in literature. References 1. Kjeldsen, P., Barlaz, M. A., Rooker, A. P., Baun, A.,
Ledin, A. and Christensen, Present and long-term composition of MSW landfill leachate: a review, Critical Reviews in Environ. Sci. and Tech., 32, 298, 2002.
2. Renou, S., Givaudan, J. G., Poulain, S., Dirassouyan, F. and Moulin, P., J. Hazardous Mat., 150, 468, 2008.
3. Fu, F and Wang, Q., Removal of heavy metals from wastewaters: an overview, J. Environmental Management, 92, 407, 2011.
4. Rodrigues, P., “Degradação Electroquímica Aplicada ao Tratamento de Lixiviados de Aterros Sanitários”. Ms. Dissertation, Universidade da Beira Interior, Covilhã, 2010.
5. �man, C. B. and Junestedt, C., Chemical characterization of landfill leachates – 400 parameters and compounds, Waste Management, 28, 1876, 2008.
6. Jensen, D. L., Ledin, A. And Christensen, T. H., Speciation of heavy metals in landfill leachate polluted groundwater, Wat. Res., 33, 2642, 1999.
7. Gounaris V., Anderson, P. R. and Thomas M. Holsen, T. M., Characteristics and Environmental Significance of Colloids In Landfill Leachate, Environ. Sci. Tech., 27, 1381, 1993.
Acknowledgements
Financial support from FEDER, through Programa Operacional Factores de Competitividade–COMPETE, and Fundação para a Ciência e a Tecnologia–FCT, for the project PTDC/AAC-AMB/103112/2008, are gratefully acknowledged.
129
Lamellar monomethynecyanines-doped mono-amidosil hybrids
S. C. Nunes1,2,3, J. Hümmer1, R. A. Sá Ferreira4, L. D. Carlos4, P. Almeida3,5, V. de Zea Bermudez1,2
1Chemistry Department, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal; 2CQ-VR, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal; 3 Chemistry Department, University of Beira Interior, Covilhã, Portugal; 4 Physics Department and CICECO, University of Aveiro, Aveiro, Portugal; 5 CICS - Centro de Investigação em Ciências de Saúde,
University of Beira Interior, Covilhã, Portugal
Abstract
Alkyl -based silsesquioxane materials were synthesized by the sol-gel process from the (CH3CH2O)3-Si-(CH2)3-NHC(=O)-(CH2)14-CH3 precursor and doped with monomethynecyanines. The Class II hybrid matrix, designated as mono-amidosil, is composed of a siliceous framework to which short methyl-terminated alkyl chains are covalently bonded through amide linkages. The doped mono-amidosil hybrid materials were obtained as solid semi-crystalline powder. The methylene chains of the hydrocarbon segment adopt all-trans conformations. The emitting centres of the m-A(14) hybrid material find the dye molecules very near to them and make the energy transfer easy, probably in an increase way.
Introduction Sol-gel chemistry [1] is one of the preferred methods to prepare advanced multifunctional organic-inorganic hybrid systems [2]. Hybrid materials doped with cationic dyes are potential candidates for optical applications [3]. The organic dyes intercalated in organic-inorganic host cages are known to exhibit significantly different properties from their solutions [4]. This effect leads to an increase of the quantum yield of the materials, thus enhancing the overall brightness of the fluorescent probe. Furthermore, the silica matrix preserves the encapsulated fluorophore from environmental factors that can affect the optical performance. In the present work we used the sol-gel process and self-assembly routes to synthesize a mono-amide cross-linked alkyl/siloxane hybrid host structure (named mono-amidosils) to which several cationic cyanines were added. The mono-amidosil framework employed has been represented by the notation m-A(14), where m denotes mono, A amide and 14 is the number of methylene group [5]. The m-A(14) mono-amidosil is highly ordered material that consists of 2D siliceous domains, separated by perpendicularly-oriented alkyl chains, self-assembled through tail-to-tail van der Waals packing and inter-molecular hydrogen bonds. Interestingly, in this hybrid the reversible order-disorder phase transition exhibited by the alkyl chains induces the emergence of a unique thermally-actuated photoluminescence (PL) memory effect during heating/cooling cycles operating between 23-120 ºC [5]. Cyanine dyes are cationic dyes belonging
to the polymethine family, where one or more methine groups link two heterocyclic rings containing at least one nitrogen atom (Scheme 1). The cyanines employed in the present work are monomethynecyanine dyes, represented by the notation SSRZ (Scheme 1) [6]. The structure of the SSRZ-doped mono-amidosils has been investigated. The luminescence features (absorption and emission measurements) of the encapsulated within the hybrid organic/inorganic films were investigated in order to determine the effect of the solid host cage on the optical properties of the chromophore.
Materials and Methods Pyridine (py, Panreac, 99.8%) and tetrahydrofuran (THF, Riedel-deHaen) were stored over molecular sieves. Amberlyst A-21 Ion-Exchange Resin (4.7 meq/g, Aldrich) was washed with THF and stored in an oven at 80 ºC. (3-aminopropyl)triethoxysilane ((CH3CH2O)3Si(CH2)3NH2, APTES, Aldrich), palmitoyl chloride (ClC(=O)-(CH2)14CH3, PC, Aldrich) and ethanol (CH3CH2OH, Fábrica de Álcool Manuel Vieira e Ca. (Irmão) Sucrs, Lda, 99.9%) were used as received. High purity distilled water (H2O) was used in all experiments. The monomethynecyanines employed were prepared
according to the thioalkyl classical method [6]. Scanning electron microscopy (SEM) images were obtained at 20 kV on a Hitachi Field Emission S-2700 microscope. SEM images were obtained at low vacuum. The sample was coated with a gold. Attenuated Total Reflectance (ATR) Infrared (IR) spectra were collected on a Thermoscientific Nicolet iS10: smart iTR, equipped with a diamond ATR crystal. For ATR data acquisition, approximately 2 mg of the sample were placed onto the crystal and the spectrum was recorded. An air spectrum was used as reference in absorbance calculations. The sample spectra were collected at room temperature in the 4000-400 cm-1 range by averaging 64 scans at a spectral resolution of 4 cm-1. The photoluminescence measurements were recorded at 12 K and room temperature, using a Fluorolog-3 (FL3 2T model) with double excitation spectrometer, fitted with a 1200 grooves/mm grating blazed at 330 nm, and a single emission spectrometer (TRIAX 320), fitted with a 1200 grooves/mm grating blazed at 500 nm, coupled to a R928 photomultiplier. The excitation source was a 450 W Xe arc lamp.
130
Table 1 Details of the synthesis of the SSRZ-doped m-A(14) mono-amidosils.
First Step Synthesis of the m-ADPTES(14) precursor
PC 1.00 mL (3.30 mmol)
APTES 774 L (3.30 mmol)
Amberlyst resin 0.841 gr (3.90 mmol)
Py 50 L (0.660 mmol)
THF 20 mL
Second step : SSRZ-doped m-A(14)
SSRZ
R = CH3; Z = Cl R = C2H5; Z = ClO4 R = CH2(C6H5); Z = I
(MM = 346.04 g/mol) (MM = 438.05 g/mol) (MM = 438.05 g/mol)
n = 40 n = 20 n = 100 n = 20 n = 100
0.0285 gr (0.0825 mmol )
0.0723 gr (0.165 mmol)
0.0144 gr (0.033 mmol )
0.0973gr (0.165 mmol )
0.0195 gr (0.033 mmol )
CH3CH2OH 700 L (13.20 mmol) 700 L (13.20 mmol) 700 L (13.20 mmol)
H2O 118 L (6.60 mmol) 118 L (6.60 mmol) 118 L (6.60 mmol)
Scheme 1: Synthetic procedure of the SSRZ-doped m-
A(14) mono-amidosils, with R = CH3, C2H5, CH2(C6H5),
4
Synthetic procedure The mono-amide alkyl/siloxane precursor was prepared according to the method we have described in detail elsewhere [5]. The first stage of the synthetic procedure involved the formation of an amide cross-link between the -Cl group of PC and the NH2 group of APTES in the presence of THF, py and Amberlyst A-21 Ion-Exchange Resin to yield the organic-inorganic hybrid precursor designated as mono-amidepropyltriethoxysilane ((CH3CH2O)3-Si-NH-C(=O)-(CH2)x-CH3, m-ADPTES(14)) (Scheme 1) (molar proportion: 1 mol APTES: 1 mol PC: 1.2 mol Amberlyst resin: 0.2 mol Py). In the second stage of the synthetic procedure, a mixture of CH3CH2OH and H2O (Si/ethanol = 4; Si/H2O = 1.5) was added to m-ADPTES(14) to promote the hydrolysis and condensation reactions characteristic of the sol-gel process, followed by the incorporation of monomethynecyanines SSRZ (Figure 1 and Scheme 1). The cyanine concentration has been represented by n, the molar ratio of amide (C=O) groups per SSRZ cyanine. Additional details of the synthesis have been collected in Table 1
Results and Discussion
SEM images show that SSC2H5ClO4- (n =20) (Figure 1a and Figure 1b) and SSCH2(C6H5)ClO4-doped m-A(14) (Figure 1c and Figure 1d) are composed of crystalline plates of nanometer thickness and micrometer lateral dimensions.
131
(a) (b)
(c) (d)
(e) (f) Figure 1: SEM images of the SSC2H5ClO4-doped m-A(14) (a (n = 100), b and c ( n = 20)) and SSCH2(C6H5)ClO4-doped m-A(14) (d and e (n = 100) and f ( n = 20)).
The FT-IR spectra (not shown) of the aCH2 and sCH2 modes of the SSRZ-doped m-A(14) mono-amidosils analysed produce two medium intensity features at 2918-2915 cm-1 (full width at half maximum (fwhm) = 21-26 cm-1) and 2850-2848 cm-1 (fwhm = 10-13 cm-1), a proof that that the alkyl chains in these samples are fully stretched (in all-trans conformations) and densely packed in all the monomethynocyanines doped analysed [7]. Interestingly, the aCH2 and sCH2 modes in FT-IR spectra of the SSRZ-doped m-A(14) mono-amidosils are downshifted with respect to those of the m-A(14) matrix (2919 and 2850 cm-1, respectively [5]. These results suggest an increase in the conformational order of the alkyl chains in the doped samples. The broad green--blue emission band observed in the m-A(14) matrix [5], that are ascribed to electron-hole recombinations occurring within oxygen-related defects present in the siliceous domains and within the amide cross linkages [8], is supressed in the SSRZ-doped m-A(14) mono-amidosil. The disappearance of the emission band from the host (m-A(14) matrix) is already reported for another dye doped [9], and has been attributed to the energy transfer from the host to the dye. The emitting
centres of the m-A(14) hybrid material find the dye molecules very near to them and make the energy transfer easy (the energy transfer probabily increase).
Conclusions In the present work, we have investigated monomethynecyanines SSRZ -doped mono-amide cross-linked alkyl/siloxane hybrids, designated as mono-amidosils, in which short methyl-capped alkyl chains are grafted to the siliceous framework through amide groups. In the dilute (n = 100) and concentrated (n = 20) SSRZ-doped m-A(14) mono-amidosils the alkyl chains adopt all-trans conformations and was observed energy transfer from the host to the dye.
References 1. Brinker, C.J.; Scherer, G. W.; Sol-gel Science, The Physics and Chemistry of Sol-Gel Processing, Academic Press, San Diego, CA, 1990 2. Sanchez, C.; Ribot, F.; New J. Chem., 18, 1007, 1994. 3. Sanchez, C.; Julián, B.; Belleville, P.; Popall, M.; J. Mater. Chem. 15, 3559, 2006. 4. J. Bujdák, Appl. Clay Sci. 34 (2006) 58. 5. Carlos, L. D.; de Zea Bermudez, V.; Amaral, V. S.;
Nunes, S. C.; Silva, N. J. O.; Ferreira, R. A. S.; Santilli, C.
V.; Ostrovskii, D.; Rocha, J. Adv.Mater. 19, 341, 2007. 6. Matsuoka M., Infrared Absorbing Dyes - Topics in
Applied Chemistry M. Matsuoka (Ed.), Cap. 3, Plenum
Press: New York, 1990. 7. Porter, M. D.; Bright, T. B; Allara, D. L.; Childsey, C. E. D.; J. Am. Chem Soc., 109, 3559, 1987; (b) Singh, S.; Wegmann, J.; Albert, K.; Muller, K., J. Phys. Chem. B, 106, 878, 2002; (c) Venkataram, N. V.; Vasudevan, S.; J. Phys. Chem. B,, 105, 7639, 2001. 8. Bermudez, V. De Zea; Ostroskii, D.; Lavoryk, S.; Gonçalves, M. C.; Carlos, L. D.; Phys Chem. Chem. Phys., 6, 649, 2004. 9. Gomez, M. L.; Fasce, D. P.; Williams, R. J. J.; Montejano, H. A.; Previtali, C. M.; Journal of Polymer Science: Part B: Polymer Physics, 46, 289, 2008.
Acknowledgements
This work was supported by Fundação para a Ciência e a Tecnologia (FCT) and FEDER (contracts PTDC/CTM/101324/2008 and PTDC/QUI-QUI/100896/2008). S. C. Nunes acknowledges FCT for a grant (SFRH/BPD/63152/2009.
132
Bioconversion of lignocellulosic residues into biogas
R. Oliveira1, A. Mendonça1, I.Gonçalves 1, H.M. Pinheiro2 and M.I. Ferra1 1University of Beira Interior, Chemistry Department, R. Marquês D’Avila e Bolama, 6200 - Covilhã, Portugal 2 Centre of Biological and Chemical Engineering, Technical University of Lisbon, Av. Rovisco Pais – 1049-001 Lisbon, Portugal Abstract Grape pomace, a by-product of the wine industry, has been shown to be an useful product for many biotechnological applications. This study aims to investigate the anaerobic biodegradation of grape pomace (GP) under anaerobic mesophilic regime. The potential of biogas production was also evaluated considering its eventual use as biofuel. Results for anaerobic biodegradation of GP were also followed by quantification of potential biogas production, COD,TOC, protein, acid precipitable polymeric lignin (APPL), soluble lignin and phenols in residual supernatant liqueur. The average biogas production for GP with a Ф of 0,40mm and 0.5 g ranged from 26 to 30 mL biogas/g SSV.d. APPL in the residual liqueur was 198 mg/L, residual phenol was of 8 ± 2 mgGAE/L and protein 185 ± 119 mg/L. These compounds altogether contribute to the residual TOC and COD. Results suggest that GP is prone to biodegradation under anaerobic regime making possible the bio-energetic valorization of this byproduct.
Introduction In Portugal winemaking industry produces in average 7 000 000 hl of wine per year, which corresponds to a vinification of 10 000 000 ton/year of grapes (Silva, 2003). In the national economy wine industry still has a large weight and valorization of residues of this industrial sector would help to maximize profit along with to protect the environment. Grape pomace (GP) is a residue of wine production containing car 8% seeds, 10% stems, 25% skins and 57% pulp and the highest levels of polyphenols found within the fruit. 1 ton of grapes produce 100lb of stems and also 160 to 240lbs of grape pomace. Grape pomace should be looked as a raw material in foods, in biotechnological processes and in energy production, good reasons to seek more efficient ways to reuse this residue, avoiding environment impacts associated to its disposal (Detroy and Hesseltine,1978; Silva, 2003). Energy production by fermentation is carried out under anaerobic conditions to produce biogas. Among the four main anaerobic steps, the hydrolysis of the fibre is the limiting step of the complete biodegradation. Bioconversion of cellulose and hemicelluloses (52% w/w) occur by hydrolysis of polysaccharides in tandem with the fermentation of the resulting oligosaccharides (fermentable sugars) to produce biogas. The aim of the present work is to investigate the anaerobic biodegradation of grape pomace under anaerobic mesophilic regime.
Materials and Methods Raw material Grape pomace, GP, used in the experiments is a by-product of winemaking industry, for red wine production, containing three red grape varieties: Trincadeira, Rufete and Tinta-Roriz. The pomace was obtained after fermentation and pressing of grapes. Before performing experiments it was dried, milled and sieved (size sieve of 0.25 and 0.4mm). It was gently supplied by a winery located in Central Region of Portugal. Anaerobic biomass Anaerobic biomass was collected from mesophilic lab-scale batch reactors, fed with a synthetic wastewater. Analyses UV-visible absorption spectra were run in a Helios Alpha spectrophometer (Unicam, UK.). Suspended solids (SS), volatile suspended solids (VSS), Chemical Oxygen Demand (COD) and pH in liquid samples were determined according to standard procedures (APHA, 2005). Total Organic Carbon (TOC) was quantified by combustion catalytic oxidation/NDIR method in a TOC-Vcsh Shimadzu. Acid insoluble lignin was quantified in the supernatant liquor after acidification with H2SO4 72% (w/w) and correction for the acid insoluble ash and protein. Acid soluble lignin was quantified in the soluble acid fraction by UV-visible spectrophotometry by measuring the absorbance of the sample at an appropriate wavelength (280 nm). Protein content was estimated by the Kjeldahl method (APHA, 2005). The total phenolic contents of the samples were determined in Gallic Acid Equivalents (GAE) based on Folin-Ciocalteu method (Magalhães et al., 2007). Anaerobic biodegradation tests The anaerobic biodegradation tests were performed in duplicate, in bottles of 250 ml capacity sealed with rubber septa. After washing with buffer phosphate solution (Na2HPO4 and NaH2PO4) in order to remove residual substrate, sludge samples were transferred to incubation flasks. After 12 h of incubation, GP (0.5g) was supplemented and incubated in the dark at 35 ± 2oC with magnetic stirring. The OxiTop® Control sensor (WTW, Germany) was used to measure the biogas pressure in the bottle headspace, and the specific methanogenic activity could then be determined. Experiments were run for car 30 days. In order to assess the rate at which the organic matter is being solubilized preliminar leaching tests were carried out, in duplicate, with GP and basal medium, at the same temperature of the biodegradation tests.
133
Results and Discussion From leaching experiments it was clear that compounds are leached from the solid to the liquid phase mainly in the first 2h of reaction (Figure 1). This indicates a sharp increase of the organic load available for bacterial metabolism, which could lead to a long lag phase, since cultures are not adapted to this type of complex substrates. Indeed cumulative biogas production curves
Figure 1 – TOC versus time obtained for leaching tests (Figure 2) depicted an acclimatization period of car 1-1.5 days. An average biogas production of 26 to 30 mLbiogas/g VSS.d was obtained, higher than the obtained in studies performed with spent brewery gains (SBG) in similar test conditions (9-16 mLbiogas/g VSS.d), which shows a higher potential biogas production of GP relatively to SBG (Tomé, 2009).
Figure 2 - Examples of time courses of cumulative biogas production for mesophilic cultures fed with GP Results for residual COD, TOC, protein, acid precipitable polymeric lignin and total phenol are shown in Table 1. As can be seen residual liquor contains mainly proteins and polymeric lignin. Total phenol content is low (8±2 mg GAE/L) indicating that these compounds are amenable to biodegradation under anaerobic mesophilic regime.
Table 1 – Residual values of TOC, COD, acid precipitable polymeric lignin (APPL), total phenolic compounds and protein obtained at the end of experiments with GP
Parameter Mesophilic regime
TOC (mgC/L) 332-566
COD (mg O2) 666 -1380
APPL (mg/L) 90-198
Phenols (mg GAE/L) 8-27
Protein (mg/L) 71-131
Conclusions GP could be considered amenable to anaerobic biodegradation under mesophilic regime, displaying a significant potential for production of biogas. Lignin, protein and phenolic compounds present in GP are degraded by non-adapted anaerobic biomass, which indicate that this type or agro-residues could play a promising role on recovery as biofuel, avoiding environment impacts associated to its disposal. References 1. APHA AWWA, 2005, Standard Methods for the
Examination of Water and Wastewater, 21 th edition., American Public Health Association/ American Water Works Association/Water Environment Federation, Washington DC, USA..
2. Detroy R.W., Hesseltine C.W. (1978). Availability and utilization of agricultural and agro industrial wastes. Process biochemistry. 13 (9): 2-8.
3. Magalhães L.M., Segundo, M.A., Reis, S., Lima, J.L.F.C., Tóth, I.V., Rangel., A.O.S.S. (2007). Automatic flow system for sequential determination of ABTS●+ scavenging capacity and Folin-Ciocalteu index: A comparative study in food products, Analytica Chimica Acta, 592:193-201
4. Silva, L.M.L.R. (2003).“Caracterização dos subprodutos da vinificação”, Millenium online (Revista do ISPV), 28:123-133
5. Tomé A. (2009). Estudo da biodegradabilidade anaeróbia de compostos lenho-celulósicos e da recuperação dos produtos residuais. Dissertação de mestrado UBI, Covilhã.
Acknowledgements The authors are grateful for the financial support from the research Unit of Textile and Paper Materials, Fundação para a Ciência e Tecnologia (FCT), Portugal.
134
Ionization of Acid Orange 8
V.M.B. Pinto 1, M.J.R.G. Pires1, M.I.A. Ferra1, A. Marques1 Chemistry Department, University of Beira Interior, 6201-001 Covilhã
Abstract
Acid orange 8 (AO8) is an azo dye widely used in dyeing processes. Nevertheless acid-base properties of this compound are not yet well known and values for its acidity constant were not found in the literature. The thermodynamic acidy constants of AO8 were determined, in the temperature range 5 to 60 ºC, from spectrophotometric measurements, using dilute aqueous solutions. The influence of sodium chloride on the acid-base equilibrium was also investigated.
Introduction
Azo dyes are of great importance in industry, namely, textile, paper, food, cosmetics and pharmaceutical industries. Acid orange 8 (AO8) is an azo dye widely used in dyeing processes [1] and so it is also present in industrial effluents. Its molecular structure is shown in Figure 1.
Figure 1 - Molecular structure of AO8
Acid-base properties of this compound are not yet well known and values for its acidity constant were not found in the literature. This work presents a study on the ionization of AO8, with the determination of thermodynamic acidity constants, from spectrophotometric measurements in the temperature range 5 to 60 ºC. Also the influence of sodium chloride on the acid-base equilibrium was investigated.
Materials and Methods
From a stock solution of AO8 (C17H14N2O4SNa), purchased from Sigma-Aldrich, 65 %, dilute solutions with molalities around 10-5 mol kg-1 were prepared in order to avoid the formation of aggregates and to apply the Lambert-Beer law. Sodium hydroxide solutions, prepared from Titrisol ampoules, Merck, were used to increase the pH of the dye solutions. Sodium chloride from Merck, 99,5 %, was dried, at 110 ºC, over night and kept in a dessicator. All solutions were prepared with purified water, with a resistivity of 18 MΩ cm, obtained by a Milli-Q185 Plus, Millipore apparatus .
UV-visible spectra were run in a Heλios γ spectrophotometer equipped with thermostatized quartz cells. The temperature was controlled by means of a thermostat, Grant LTD 20, and a digital thermometer Hart Scientific 1502.
Results and Discussion
Spectra of aqueous AO8 solutions, at 25 ºC, are presented in Figure 2 at three different pH values. Absorbance measurements were taken at 490 nm, the analytical wavelength, where there is a big difference in absorbance between the two species [2].
Figure 2 - Spectra of AO8, 4.0x10-5 mol kg-1 in water, NaOH 0.005 M and NaOH 1.0 M. The dye ionization corresponds to the loss of a hydrogen ion from the protonated species, HA-: HA- ↔ H+ + A2- (1) and the thermodynamic ionization constant, K, is given by equation (2)
HA
HA
HA
HA
m
mmK
γ
γγ= (2)
where m and γ represent the molality and activity coefficient, respectively, of the indicated species. The electric charges were omitted for simplicity. The value of mH was known from the solutions preparation and the ionic product of water [3] and the ratio mA/mHA was obtained from absorbance measurements of solutions of exactly the same dye molality at pH lower than 10.0, higher than 12.0 and at intermediate pH values. The ionic activity coefficients were calculated by means of the Debye-Hückel equation, taken into account the Bates-Guggenheim convention [4], as given by equation (3),
135
21
21
iI5.11
IAlog
+
−=γ (3)
where i refers to ions HA-, A2- or H+ and A is the Debye-Hückel coefficient [5]. The temperature dependence of pK (pK = -log K) is shown in Figure 3.
Figure 3 – Temperature dependence of AO8 pK
Equation (4) expresses the variation of pK with the temperature, t/ ºC (R2 =0.9992). pK= 12.955 ± 0.016-(0.0379 ± 0.0014)t + + (0.0002 ± 2 E-05)t2 (4)
Another set of measurements was performed using NaCl 0.1 mol kg-1 solutions as solvent and stoichiometric acidity constants, Km, were determined in this ionic medium. The variation of pKm (pKm = -log
Km) with temperature is illustrated in Figure 4, for both water and NaCl 0.1 mol kg-1 solution as solvents.
Conclusions
The AO8 acidity constant was found to be lower than that for AO7 (pK= 11.4) [ 6 ], as expected. The presence of sodium chloride in AO8 dye solutions increases its acidity constant.
References
1. Zollinger, H., Color Chemistry – Synthesis, Properties and Applications of Organic Pigments, Third revised edition, Wiley- VCH, Weinheim, 2003.
2. Albert, A., Serjeant, E.P., The Determination of Ionization Constants – A Laboratory Manual, Third Edition, Chapman and Hall, New York, 1984.
3. Harned, H.S. and Owen, B.B., “The Physical Chemistry of Electrolytic Solutions, 3ª ed., New York, Reinhold Publishing Corporation, 1969.
4. Bates, R.G. and Guggenheim, E.A., Pure Appl. Chem., 1, 163, 1960.
5. Robinson R.A., Stokes R.H., “Electrolyte Solutions”, 2ª ed. Revista, London, Butterworth and Co., 1970.
6. Oakes, J. Gratton, P., J. Chem. Soc., Perkin Trans. 2, 1857, 1998.
Acknowledgements
The authors are grateful for the financial support from the Research Unit of Textile and Paper Materials, Fundação para a Ciência e Tecnologia (FCT), Portugal.
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136
Preparação de derivados de esqueleto guaieno a partir de Guaiol e Bulnesol
Sofia Pombal1, Jesus Rodilla1, Lúcia Silva1
1 Unidade de Materiais Têxteis e Papeleiros, Universidade da Beira Interior, Rua Marquês d’Ávila e Bolama, 6200 Covilhã.
Abstract
A essência de Bulnesia sarmientoi foi
sujeita a cromatografia em coluna tendo-se
isolado cinco compostos: � - gauieno (1), � -
bulneseno (2), guaiol (3), bulnesol (4), hanamiol (5).
A partir da fracção da mistura de
guaiol e bulnesol ( %12,5�� ) foi feita a
reacção de eliminação tendo-se obtido três
compostos. O � - gauieno (1) e dois novos
epóxidos (6) e (7).
Introdução
A Bulnesia sarmientoi é uma planta
nativa da região da Argentina e Paraguai. O
Guaic é o seu óleo e é extraído das aparas
de madeira desta árvore através de uma
destilação a vapor. Este óleo pode ser
usado como ingrediente de perfumes ou
ter uma utilização medicinal. Tem também
uma grande actividade repelente sobre os
pulgões, nomeadamente a duas espécies
testadas (Myzus persicae e Rhodalosiphum padi) [1].
O óleo essencial apresentou uma
actividade anti – fúngica muito boa frente
às três espécies de Fusarium testadas,
sendo o F. solani e o F. moniliforme os
mais sensíveis. Nem o óleo nem os seus
componentes maioritários foram
fitotóxicos frente a Lacuna sativa.
O Guaiol e o Bulnesol são álcoois
terciários que reagem facilmente mas em
contrapartida têm um processo de acetilação
bastante débil em condições de temperatura
elevada e meio ácido.
Método experimental:
A reacção de eliminação foi realizada
à temperatura ambiente, com POCl3.piridina
tendo-se obtido uma mistura de três produtos,
que foram separados por cromatografia em
coluna e posteriormente foram identificados
por métodos espectrocópicos de RMN 1H e 13C, infravermelho, de massas e foi ainda
medida a sua actividade óptica.
A 1 g da mistura de guaiol/bulnesol
dissolvida em 30 mL de diclorometano sob
agitação magnética, adicionou-se 0,37 mL de
piridina e 0,42 mL de POCl3, deixou-se em
agitação durante 30 horas.
A mistura reaccional foi neutralizada
com 5 mL de uma solução aquosa de NaHCO3
10 %. Lavou-se o produto da reacção com
água destilada e dietil éter. A fase orgânica foi
seca sob sulfato de sódio anidro, filtrou-se e
evaporou-se o solvente no evaporador
rotativo.
Depois preparou-se uma
cromatografia em coluna, e separam-se os 3
componentes da mistura, sobre sílica-gel,
usando como eluente um gradiente de
hexano/dietil éter de polaridade crescente.
Resultados e discussão
Após purificação dos produtos da
reacção identificou-se o produto de
eliminação, � -gauieno (1), com um
rendimento de 15,36%.
Conclui-se que ainda existiam mais
dois compostos, (6) e (7), com um rendimento
final de 21,8% e 1,9%, respectivamente. Em
contrapartida, ainda houve um rendimento de
4,3% de produto que não reagiu. Finalmente,
existiu uma grande parte do produto que
polimerizou, com um rendimento de 49%.
137
Referências
[1] J.M. Rodilla, L.A. Silva, N. Martinez, D. Lorenzo, D. Davyt, L. Castillo C. Giménez, R. Cabrera, A. González-Coloma, J. Zrostlíková, E. Dellacassa, Advances in the identification and agrochemical importance of sesquiterpenoids from Bulnesia sarmientoi essential oil.
(1)
H
(2)
OH
(3) OH(4)
(6)
O
(7)
O
O
OH
(5)
138
Trihalomethanes in wastewaters and risk for aquatic environment
A. S. Rebelo 1, T. A. Anágua2, M.I.A. Ferra2, A.Marques2 1Adm. Região Hidrog. Algarve, 2Chemistry Department, University of Beira Interior, 6201-001 Covilhã
Abstract
The water treatment is a key-factor to reduce the waterborne diseases, in particular, the infectious diseases caused by pathogens. Accordingly, disinfection is a crucial stage in the water treatment to ensure a safe public supply. The disinfection, namely by chemical processes, can lead to secondary reactions with the natural organic matter and subsequent formation of halogenated compounds, such as trihalomethanes (THM), regarded as particularly dangerous to human health, following their potential as cancer precursors, and to the aquatic environment due to their toxicity, persistence and bioaccumulation. The potential formation of THM in synthetic waste waters was assessed and compared with real data from three waste water treatment plants located in Algarve’s region. The results were correlated with the risk that these substances, in particular, chloroform, could pose to water bodies regarding the reuse of waste water.
Introduction
The water disinfection is a key factor to reduce waterborne pathogens and an essential step to ensure a safe water supply to population. However, the chemical disinfection may lead to secondary reactions and to the occurrence of by-products [1-3]. Chlorine has been widely used in water disinfection for multiple purposes: drinking, recreational and wastewaters [4,5]. The use of chlorination techniques in treated wastewaters (TWW) is particularly important for reuse trials, due to the need of a residual disinfection potential to prevent recontamination of TWW during its storage.
The chloroform was identified as a priority substance according to the Water Framework Directive (WFD), i.e., is considered a substance that presents a significant risk to or via the aquatic environment [6,7]. This work presents a study on THM formation in synthetic wastewaters, disinfected with different concentrations of sodium hypochlorite (NaOCl). A comparison with real monitoring data from three urban wastewater treatment plants (WWTP) located in Algarve’s region is shown. The risk to the aquatic environment was estimated by a ratio of the Predicted Environmental Concentration (PEC) and Predicted No-Effect Concentration (PNEC), i.e., an appraisal of the risks for the receiving water bodies that might emerge by the chloroform formation [8-10].
Materials and Methods Samples of 1 L of synthetic wastewater were prepared in the laboratory according to Saby et al. [11] to guarantee a fixed composition and characteristics (table-1). Table 1 – Characteristics and composition of synthetic wastewater [11]
Characteristics Concentration / mg L-1
COD 330 mgL-1 O2
NTotal 58 mgL-1 N
Ammonia 38 mgL-1 N-NH4
Nitrates 2 mgL-1 N-NO3
PTotal 10 mgL-1 P
Suspended Solids 0 mgL-1
Temperature 20 ºC
pH 7.7
Composition Concentration / mg L-1
Peptone 75
Yeast extract 150 Phosphate buffer solution:
KH2PO4 68
K2HPO4 174
Na2HPO4 169.6
NH4Cl 120.6
CaCl2 54.26
MgSO4 22,5
FeCl3.6H2O 0,25
For the chlorination, a sodium hypochlorite solution (NaOCl) with 13% active chlorine was used. The volumes of NaOCl solution varied from 0 to 2 mL. The contact times were: 0, 2, 6, 8, 10, 12, 24, 48, 72, 96 and 120 hours. The THM: CHCl3, CHBrCl2, CHBr2Cl and CHBr3 were determined by the purge and trap technique. For this study, monitoring data from TWW of three urban WWTP were collected from the competent authorities (Algarve River Basin District Administration). The environmental risk posed by the chloroform present in TWW discharges is estimated by the calculation of the ratio PEC/PNEC per discharge [9,10]. The PEC determination was made by two approaches: • PEC1: Use of all measurable results from the
WWTP; • PEC2: Use of all results from the WWTP and the
application of the rule described in the European
139
directive 2009/90/EC: “Where the amounts of physico-chemical or chemical measurands in a given sample are below the limit of quantification, the measurement results shall be set to half of the value of the limit of quantification concerned for the calculation of mean values” [12].
For the PNEC values, the Environmental Quality Standard (EQS) from the European directive 2008/105/EC [7] was used.
Results and Discussion
In the chlorinated synthetic wastewaters, only chloroform was quantifiable and the other three THM were barely detected. Those results are consistent with the composition of the synthetic wastewaters since no brominated compounds were added. It was found that the major formation occurs in the first two hours of reaction. After that period, the concentration of THM tends to remain constant. Table 2 gives the results from real monitoring data from three waste water treatment plants, A, B and C. Table 2 – Monitoring data from WWTP
Using the EQS for chloroform, i.e., 2,5 μg/L for surface waters – inland, transitional and coastal waters [7], and considering the worst case for the receiving waters, i.e., no dilution effect, the ratio PEC/PNEC(EQS) is higher than one, which means there is risk for the aquatic environment, except for the WWTP B.
Conclusions
In this study the THM formation in chlorinated synthetic wastewaters was observed and chloroform was the dominant species. The chloroform concentration in the synthetic effluents was similar to that found in two WWTP. For small streams with torrential regime flow and a low dilution potential, chlorinated TWW seems to present a risk for the aquatic environment, in terms of chloroform, since the ratio PEC/PNEC tends to be higher than one. Since the use of chlorination techniques in TWW is a common practice for reuse trials, due the need of a residual disinfection potential to prevent recontamination of the effluents during their storage, further studies on the chlorination process and THM formation are needed to assess the risk for the water bodies.
References 1. Walfish, L. and Janauer, G., Water, Air, and Soil
Pollution, 12, 477, 1979. 2. Brown, M., Miller, S. and Emmert, G., Analytica
Chimica Acta, 592, 154, 2007. 3. Pavón, J., Martín, S., Pinto, C. and Cordero, B.,
Journal of Chromatography A, 1194, 103, 2008. 4. Solsona, F. and Vega, J., Water desinfection. Lima:
Pan American Center for Sanitary Engineering and Environmental Sciences, 2003.
5. Wang, L., Hung, Y. and Shammas, N., Handbook of environmental engineering: physicochemical treatment processes. Vol. 3. Humana Press Inc., Totowa, 2005.
6. European Commission, Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000, JO L 327, 1, 2000.
7. European Commission, Directive 2008/105/EC of the European Parliament and of the Council of 16 December 2008, JO L 348, 84, 2008.
8. Fairman, R., Mead, C. and Williams, P., Environmental risk assessment – Approaches, experiences and information sources. Environmental Issue Report n.º 4. European Environment Agency, Copenhagen, 1998.
9. Tauxe-Wuersch, A., De Alencastro, L., Grandjean, D. and Tarradellas, J., Water Research, 39, 1761, 2005.
10. Tong, C., Zhuo, X. and Guo, Y., J. Agric. Food Chem, 59, 7303, 2011.
11. Saby, S., Djafer, M. and Chen, G., Water Research, 36, 656, 2002.
12. European Commission, Directive 2009/90/EC of the European Parliament and of the Council of 31 July 2009, JO L 201, 36, 2009.
Acknowledgements
The authors gratefully acknowledge the Algarve River Basin District Administration and the Research Unit of Textile and Paper Materials, Fundação para a Ciência e Tecnologia (FCT), for financial support
WWTP A B C
CHCl3 / μg/L
PEC1 11,6 2,33 190 PEC2 7,55 1,88 190
PEC1/PNEC 4,63 0,933 75,9 PEC2/PNEC 3,02 0,750 75,9
140
New N-carboxyalkylthiacarbocyanine dyes functionalized with amino derivatized groups as ligands in dye-affinity chromatography
T. E. Silva, P. Almeida, R. E. F. Boto
Health Sciences Research Center, University of Beira Interior, 6201-001 Covilhã, Portugal
Abstract
Some derivatized dicarboxyalkylthiacarbocyanine precursors were synthesized envisioning the use of these new cyanines as ligands for Affinity Chromatography (AC).
The introduction of three different groups in the 6-position of the cyanine benzothiazole nucleous require the previous reaction of 6-amino-2-methylbenzothiazole with decanoyl chloride, benzenesulfonyl chloride and phthalic anhydride to afforded 6-decanoyl-2-methylbenzothiazole, 6-benzenesulfonyl-2-methyl- benzothiazole and 6-phthalamide-2-methylbenzothiazole, respectively. Quaternary salts were obtained by the reaction of these compounds with 11-bromoundecanoic acid. Finally, the thiacarbocyanine dyes should be obtained by condensation of the resulting quaternary salts with triethyl orthoformate in the presence of pyridine.
Introduction
AC has proven to be the most effective technique for the purification and separation of proteins from complex mixtures [1]. For large-scale purification of proteins, Dye-AC has developed into an important method.
The utility of the reactive dyes as affinity ligands results from their unique chemistry, which confers both the ability to interact with a large number of proteins as well as easy immobilization on typical adsorbent matrices [2]. Although affinity adsorbents based on biological ligands such as immobilized antibodies, lectins and nucleotide cofactors appear to be highly successful, their use at a preparative scale is limited because of their instability, expense and low capacity [1].
Cyanines are cationic dyes, with the positive charge associated with heterocyclic nitrogen atoms at the ends of a conjugated polymethine chain [3]. Cyanines, once capable to bind to a chromatographic support, are suitable candidates to affinity ligands since their ability to establish a combination of specific types of hydrophobic, hydrophilic, ionic and π–π interactions opens the possibility of an increased selectivity between these type of dyes and the biomolecules to be purified [4].
Recently, a carboxyalkylthiacarbocyanine bounded onto cellulose beads proved to be an effective and selective tool in the separation of an artificial mixture of standard
proteins, since the carboxyl groups are amenable to link covalently to macromolecules with nucleophilic centers like cellulose [3]. To improve even more the affinity with proteins, the derivatization of these thiacarbocyanines is desirable, with different lateral chains displaying the selective combination of interactions between the ligand and the protein to be purified.
Amino derivatized carbocyanine synthesis
2-Methyl-6-nitrobenzothiazole (2) was prepared by direct nitration, namely by stirring 2-methylbenzothiazole (1) with concentrated acid sulfuric in an ice bath, after the dropwise addition of a nitric acid/sulfuric acid solution (Scheme 1). The 6-amine-2-methylbenzothiazole (3) was obtained after sonication of 2 with concentrated chloridric acid and powdered iron, in ethyl alcohol 80% [3].
Scheme 1
The derivatization of amino group occurred under mild conditions at room temperature. 6-Decanoyl-2-methylbenzothiazole, 6-benzenesulfonyl-2-methylbenzo- thiazole and 6-phthalamide-2-methylbenzothiazole (4a-c) were obtained reacting 3 with decanoyl chloride, benzenesulfonyl chloride and phthalic anhydride, respectively (Scheme 2). The reaction was completed after 24 to 48h and the solids so obtained were recrystallized from methanol. The quaternary salt synthesis was performed by reacting the 4a-c with 11-bromodecanoic acid under agitation at different
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temperatures (100 to 150ºC). The reaction was completed after 48h and the solids were recrystallized from methanol.
The compounds obtained were fully characterized by 1H and 13C NMR and by FTIR
Results and Discussion
The synthesis of several amino derivative dyes precursors envisioning their posterior use as ligands for AC, intended to improve the selective affinity of this class of dyes to the protein to be purified, clarifying the influence of structural variations in the dicarboxylalkylthiacarbocyanine dye. As example of this strategy, while the introduction of additional alkyl groups in 6a will increment hydrogen bond between the immobilized ligand and target proteins, the introduction of a second aromatic moiety in 6c will potentially increase the π–π interactions.
Conclusion
The synthesis of some derivatized dicarboxylalkylthiacarbocyanines was described. The synthetic route depicted allows preparing some amino derivatized dicarboxylalkylthiacarbocyanines which may establish different kinds of interactions between these dyes and the biomolecules to be purified. Additionally, it is our purpose to explore the same synthetic route here described using microwave. All cyanine dyes here obtained will be tested as new ligands in affinity chromatography, after suitable immobilization onto
The cyanine synthesis was performed by the condensation of the resulting quaternary salts with triethyl orthoformate, in refluxing pyridine, for 18 h. Scheme 2
cellulose, expecting to demonstrate the influence of different kinds of structural interactions in their chromatographic behavior.
References
[1] Labrou, Nikolaos E. Affinity Chromatography, vol. 147: 13 Springer Protocols– Jan 1, 2000. [2] Boyer P.M. and Hsu J.T. , Protein purification by dye-ligand chromatography, A. Fiechter, Editor, Advances in biochemical engineering, vol. 49 Springer-Verlag, Berlin 1–44,1993. [3] Hrobárik, P., Sigmundová, I., and Zahradnik, P. Synthesis, 4, 600, 2005. [4] Boto R.E.F., Anyanwu U., Sousa F., Almeida P and Queiroz J.A. Biomed Chromatogr 23, 987, 2009.
Acknowledgements
The authors are grateful to FCT (Lisbon), for financial support PTDC/QUI-QUI/100896/2008 and to IAESTE Portugal.
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triethylorthoformate, pyridine, 150ºC
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a) Decanoyl Chlorideb) Benzenesulfonyl Chloride c) PhthalicAnhydride
a - R = NHCO(CH8)CH3
b - R = NHSO2C6H5 c - R = N(CO)2C6H5
