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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The development and performance of anodic biofilms in microbial fuel cells

Michie, Iain January 2012 (has links)
Microbial fuel cell (MFC) systems capable of both treating wastewaters and recovering energy have the potential for successful scale-up as a low carbon technology. These systems utilize microorganisms residing in biofilms as biocatalytic agents in the conversion of reduced substrates to electrical energy. As such, it is important to understand how MFC anodic biofilms develop over time and also how environmental parameters such as substrate type, temperature, carbon support material, anode architecture and optimized applied potentials also affect electrogenic performance. The type of substrate was found to have a large impact on the acclimation and performance of electrogenic biofilms. Acetate produced the highest power density of 7.2 W m 3 and butyrate the lowest at 0.29 W m"3, but it was also found that biofilm acclimation to these different trophic conditions also determined the MFC response to different substrate types i.e. both acetate and butyrate substrates produced power densities of 1.07 and 1.0 W m"3 respectively in a sucrose enriched reactor. The use of MFCs for wastewater treatment in temperate regions requires the development of reactor systems that are robust to seasonal fluctuations and are energy efficient. As such, system performance was examined at three different operating temperatures (10°C, 20°C and 35°C). At each temperature a maximum steady-state voltage of 0.49 V ± 0.02V was achieved after an operational period of 47 weeks, with the time to reach steady-state voltage being dependent on acclimation temperature. The highest COD removal rates of 2.98g COD L^d * were produced in the 35°C reactor but coulombic efficiencies (CE) were found to be significantly higher at pyschrophilic temperatures. Acclimation at different operating temperatures was found to a have a significant effect on the dynamic selection of psychrophilic, psychrotolerant and mesophilic anode respiring bacteria (ARB) and also influence the development of biofilm biomass, methanogenesis and electrogenic activity. Although start-up times were inversely influenced by temperature the amount of biomass accumulation increased with higher operational temperatures and this had a direct impact on biocatalytic performance. The three dimensional structure and porosity of different carbon anode materials affected anodic performance by determining the levels of surface area available for biofilm growth and the capacity for mass transfer to occur. Novel helical electrode configurations were used to look at the effect of altering turbulent flows to increase mass transfer rates and carbon surface areas available for electrogenic growth. The spiral with the highest amount of carbon veil and the smallest gap produced the highest power production of 11.63 W m"3 . Comparative studies of a logic controlled and un-controlled external load impedance showed that control affected the biocatalyst development and hence MFC performance. The controlled MFC better optimized the electrogenic anodic biofilm for power production, indicating that improved power and substrate conversion can be achieved by ensuring sustainable current demand, applied microbial selection pressures and near-optimal impedance for power transference.
2

Impactos das políticas públicas brasileiras de incentivo à inovação: análises das redes participantes nos Fundos Setoriais de biotecnologia e energia / Brazilian technology development funds impacts: a network analysis of the biotechnology and energy of the Fundos Setoriais

Ribeiro, Wander Leonhardt 07 October 2013 (has links)
A presente pesquisa tem por objetivo avaliar os impactos estruturais, de processo e desempenho gerados nas redes de inovação caracterizadas pelas empresas e as Instituições de Ciência e Tecnologia estabelecidas para tomada de recursos dos Fundos Setoriais para Ciência e Tecnologia brasileiros. Isto porque os fundos setoriais representam importantes pilares do sistema nacional de inovação brasileiro e, como foram criados a pouco mais de uma década, o momento é oportuno para sua avaliação. Nessa pesquisa foram analisados os fundos setoriais de energia e biotecnologia. O presente estudo utilizou dados secundários disponíveis nas Bases de Dados da FINEP, que representam cerca de 70% do total desses fundos em projeto e também em volumes de recursos. Os indicadores de análise são posicionados em diferentes disciplinas científicas e diferentes níveis de análise e foram consolidados à luz da teoria do modelo de gestão da inovação aberta. A pesquisa também contribui para disseminação e consolidação da cultura de inovação no país e da importância das políticas governamentais de fomento à inovação. Os setores de biotecnologia e energia são de forte apelo e custo social, estão relacionados entre si e são intensos em pesquisa e desenvolvimento. São, portanto, participantes naturais do sistema brasileiro de inovação e tomadores dos fundos setoriais. Além disso, esses setores são importantes setores para desenvolvimento econômico regional, constituindo assim, áreas importantes para o campi da USP de Ribeirão Preto. A região está implantando um parque tecnológico que contempla essas áreas na sua diversidade de atuação. Finalmente, esses temas são de interesse do pesquisador que tem paixão e carreira em desenvolvimento e inovação. Portanto, a consolidação da pesquisa como competência no meu currículo constitui motivo fundamental de integração e dedicação no programa de mestrado. / The present research target to evaluate structural impacts, as well as process impacts and performance impacts on the innovation networks characterized for companies and Science and Technological Institutions established to affiliate on Brazilian Technological Development Funds - Fundos Setoriais para Ciência e Tecnologia. That is because the Brazilian Technological and Development Funds represent main political instruments for the national innovation system. The research used secondary data available at FINEP which represent about 70% of the number of projects as well as the total funds of the program. At present research Brazilian technological development funds for biotechnology and energy were analyzed. The analyses indicators are set on multiple analyses levels as well as on different research disciplines that were consolidated under the light of the open innovation management model. The research also contributes to dissemination and consolidation of the innovative culture in Brazil as well as the importance of public innovation funding policies adopted by countries. The biotechnology and energy sectors represent strong social and cost appeal, are correlated each other and are intense on research and development investment. They are therefore natural participants on the Brazilian innovation system and technological development funds users. Further, those sectors represent important sectors for the regional economic development and thought, to the Ribeirão Preto USP university campi. The region is building its technological park at present moment which considers its areas as strategic to its development. Finally, those themes are important to the researcher who has passion and a carrier on development and innovation. The consolidation of the research on mine curriculum is the main objective to affiliate on the master program.
3

Impactos das políticas públicas brasileiras de incentivo à inovação: análises das redes participantes nos Fundos Setoriais de biotecnologia e energia / Brazilian technology development funds impacts: a network analysis of the biotechnology and energy of the Fundos Setoriais

Wander Leonhardt Ribeiro 07 October 2013 (has links)
A presente pesquisa tem por objetivo avaliar os impactos estruturais, de processo e desempenho gerados nas redes de inovação caracterizadas pelas empresas e as Instituições de Ciência e Tecnologia estabelecidas para tomada de recursos dos Fundos Setoriais para Ciência e Tecnologia brasileiros. Isto porque os fundos setoriais representam importantes pilares do sistema nacional de inovação brasileiro e, como foram criados a pouco mais de uma década, o momento é oportuno para sua avaliação. Nessa pesquisa foram analisados os fundos setoriais de energia e biotecnologia. O presente estudo utilizou dados secundários disponíveis nas Bases de Dados da FINEP, que representam cerca de 70% do total desses fundos em projeto e também em volumes de recursos. Os indicadores de análise são posicionados em diferentes disciplinas científicas e diferentes níveis de análise e foram consolidados à luz da teoria do modelo de gestão da inovação aberta. A pesquisa também contribui para disseminação e consolidação da cultura de inovação no país e da importância das políticas governamentais de fomento à inovação. Os setores de biotecnologia e energia são de forte apelo e custo social, estão relacionados entre si e são intensos em pesquisa e desenvolvimento. São, portanto, participantes naturais do sistema brasileiro de inovação e tomadores dos fundos setoriais. Além disso, esses setores são importantes setores para desenvolvimento econômico regional, constituindo assim, áreas importantes para o campi da USP de Ribeirão Preto. A região está implantando um parque tecnológico que contempla essas áreas na sua diversidade de atuação. Finalmente, esses temas são de interesse do pesquisador que tem paixão e carreira em desenvolvimento e inovação. Portanto, a consolidação da pesquisa como competência no meu currículo constitui motivo fundamental de integração e dedicação no programa de mestrado. / The present research target to evaluate structural impacts, as well as process impacts and performance impacts on the innovation networks characterized for companies and Science and Technological Institutions established to affiliate on Brazilian Technological Development Funds - Fundos Setoriais para Ciência e Tecnologia. That is because the Brazilian Technological and Development Funds represent main political instruments for the national innovation system. The research used secondary data available at FINEP which represent about 70% of the number of projects as well as the total funds of the program. At present research Brazilian technological development funds for biotechnology and energy were analyzed. The analyses indicators are set on multiple analyses levels as well as on different research disciplines that were consolidated under the light of the open innovation management model. The research also contributes to dissemination and consolidation of the innovative culture in Brazil as well as the importance of public innovation funding policies adopted by countries. The biotechnology and energy sectors represent strong social and cost appeal, are correlated each other and are intense on research and development investment. They are therefore natural participants on the Brazilian innovation system and technological development funds users. Further, those sectors represent important sectors for the regional economic development and thought, to the Ribeirão Preto USP university campi. The region is building its technological park at present moment which considers its areas as strategic to its development. Finally, those themes are important to the researcher who has passion and a carrier on development and innovation. The consolidation of the research on mine curriculum is the main objective to affiliate on the master program.

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