Orientador: Aneirson Francisco da Silva / Resumo: A Estampagem a Frio é um processo de conformação plástica de chapas metálicas, que possibilita, por meio de ferramentas específicas, obter componentes com boas propriedades mecânicas, geometrias e espessuras variadas, diferentes especificações de materiais e com boa vantagem econômica. A multiplicidade destas variáveis gera a necessidade de utilização de técnicas estatísticas e de simulação numérica, que suportem a sua análise e adequada tomada de decisão na elaboração do projeto das ferramentas de conformação. Este trabalho foi desenvolvido em uma empresa brasileira multinacional de grande porte que atua no setor de autopeças, em seu departamento de engenharia de projetos de ferramentas, com o propósito de reduzir o estiramento e a ocorrência de trincas em uma travessa de 6,8 [mm] de aço LNE 380. A metodologia proposta obtém os valores dos fatores de entrada e sua influência na variável resposta com o uso de técnicas de Delineamento de Experimentos (DOE) e simulação pelo método de Elementos Finitos (FE). Uma Função Empírica é desenvolvida a partir desses dados, com o uso da técnica de regressão, obtendo-se a variável resposta y (espessura na região crítica), em função dos fatores influentes xi do processo. Com a Otimização via Simulação Monte Carlo (OvSMC) insere-se a incerteza nos coeficientes desta Função Empírica, sendo esta a principal contribuição deste trabalho, pois é o que ocorre, por via de regra, na prática com problemas experimentais. Simulando-se por FE as ferram... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

O consumidor está cada vez mais consciente da relação entre dieta e doença, que tem impulsionado as pesquisas sobre alimentos funcionais e seus efeitos sobre o corpo. O papel dos óleos e gorduras na nutrição humana tem sido intensamente estudado e discutido por décadas. Tem sido enfatizada a importância da ingestão de ômega-3, ômega-6 e ômega-9 ácidos graxos redução de ácidos graxos saturados e, mais recentemente, controle da ingestão de ácidos graxos trans. Através da mistura e interesterificação química e enzimática de óleos e gorduras, gorduras trans-livre pode ser produzido. Mistura de gordura, foram formuladas por misturas ternárias de estearina de palma, uma gordura láurica (óleo de coco ou óleo de palmiste) e um óleo poliinsaturado (óleo de canola ou azeite de oliva) em diferentes proporções que foram interesterificadas. Neste trabalho, foram produzidos lipídios estruturados por interesterificação química e enzimática. A interesterificação química foi realizada nas seguintes condições: a 88 °C, 60 minutos de reação, 0,4% de catalisador metóxido de sódio, sob agitação e vácuo. A interesterificação enzimática, sendo realizada com duas lipases comerciais Thermomyces lanuginosa e Rhizomucor miehei, com seletividade sn-1,3. A interesterificação enzimática por batelada foi realizado seguindo um planejamento matriz central compósito rotativo em função da temperatura e da composição do meio, estearina de palma, óleo de palmiste e azeite de oliva e catalisado pelas lipases comerciais. O decréscimo do conteúdo de gordura sólida foi observado a 10 e 35 °C após a interesterificação. O biorreator contínuo foi operado nas seguintes condições: mistura de estearina de palma, óleo de palmiste, azeite de oliva (45:30:25), 10 gr de biocatalisador, 65 °C, com tempo de residência de 7 min e por 226 h para Thermomyces lanuginosa e 188 h para Rhizomucor miehei. A atividade do biocatalisador foi avaliada em termos da diminuição do conteúdo de gordura sólida a 35 °C, o qual é um parâmetro chave na produção de margarinas. O perfil de inativação do biocatalisador pode ser bem descrita pelo modelo de desativação de primeira ordem: meia-vida de 88 e 60 h foram estimados quando Thermomyces lanuginosa e Rhizomucor miehei, respectivamente, foram utilizados. Os óleos puros, as misturas originais e interesterificadas foram avaliados quanto à composição de ácidos graxos e triacilgliceróis, distribuição regioespecífica dos ácidos graxos nos triacilgliceróis, ponto de fusão e amolecimento, consistência, conteúdo de gordura sólida, comportamento de fusão e cristalização, estabilidade oxidativa, estrutura cristalina e polimorfismo. A interesterificação química e enzimática promoveram diminuição de triacilgliceróis trissaturados e triinsaturados e aumento dos monossaturados-diinsaturados e dissaturados-monoinsaturados, o que resultou no respectivo decréscimo dos pontos de fusão e amolecimento, consistência e conteúdo de gordura sólida, aumentando a plasticidade das gorduras. As curvas de fusão e cristalização das misturas foram modificadas pela alteração da composição dos triacilgliceróis pela interesterificação química e enzimática. Estabilidade térmica e a temperatura de oxidação da estearina de palma, óleo de coco e óleo de canola e suas misturas foram dependente da composição de ácidos graxos e independente da interesterificação química. Os resultados mostram que a interesterificação química e enzimática oferecem uma ferramenta útil para a concepção de gorduras com sintonizáveis propriedades físico-químicas, melhorando em relação a esse das gorduras de partida. / The consumer is becoming more aware of the relationship between diet and disease, which has driven the research on functional foods and their effects on the body. The role of fats and oils in human nutrition has been intensively studied and discussed for decades. It has been emphasized the importance of intake of omega-3, omega-6 and omega-9 fatty acids, reduction of saturated fatty acids and, more recently, control of intake of trans fatty acids. Through the blend and interesterification of oils and fats, trans-free fats can be produced. Fat blends, formulated by ternary blends of palm stearin, lauric fat (coconut oil and palm kernel oil) and polyunsaturated oils (canola oil and olive oil) were done in different ratios. In this work, were produced by chemical and enzymatic interesterification. Chemical interesterification was performed under the following conditions: at 88°C, 60 minutes reaction times, 0.4% sodium methoxide, under agitation and vacuum. For enzymatic interesterification being carried out with two commercial lipases Thermomyces lanuginosa e Rhizomucor miehei, with selectivity sn-1,3. Batch enzymatic interesterification were performed, following central composite rotatable designs (CCRDs) as a function temperature and media of palm stearin, palm kernel oil and olive oil formulation and catalyzed by a commercial immobilized lipase. A decrease in all SFC values of the blends at 10 °C and 35°C was observed upon interesterification. The bioreactor operated continuously: mixture of palm stearin, palm kernel oil and olive oil (45:30:25, wt %), at 65 °C, at a residence time of 7 min and for 226 h to Thermomyces lanuginosa and 188 h to Rhizomucor miehei.. Biocatalyst activity was evaluated in terms of the decrease of the solid fat content at 35 °C of the blends, which is a key parameter in margarine manufacture. The inactivation profile of the biocatalyst could be well described by the first-order deactivation model: Half-lives of 88 and 60 h were estimated when Thermomyces lanuginose and Rhizomucor miehei, respectively, were used. Pure oil, the original and interesterified blends were examined for fatty acids and triacylglycerols composition, regiospecific distribution of fatty acids in triacylglycerols, melting and softening points, consistency, solid fat content, thermal behavior, oxidation stability, crystalline microstructure and polymorphism. Chemical and enzymatic interesterification caused reduction of trisaturated and triunsaturated and increase in monosaturated-diunsaturated and disaturated-monounsaturated, lowering the initial melting and softening points, consistency and solid fat content, increasing plasticity of fats. Melting and crystallization curves were significantly modified by changing the composition of triacylglycerols by chemical and enzymatic interesterification. The thermal stability and oxidation temperature of palm stearin, coconut oil and canola oil and their blends were dependent on fatty acid composition and independent on chemical interesterification. The results show that the chemical and enzymatic interesterification provides a useful tool to design fats with tunable physicochemical properties, improved compared to that of the starting fats.

O consumidor está cada vez mais consciente da relação entre dieta e doença, que tem impulsionado as pesquisas sobre alimentos funcionais e seus efeitos sobre o corpo. O papel dos óleos e gorduras na nutrição humana tem sido intensamente estudado e discutido por décadas. Tem sido enfatizada a importância da ingestão de ômega-3, ômega-6 e ômega-9 ácidos graxos redução de ácidos graxos saturados e, mais recentemente, controle da ingestão de ácidos graxos trans. Através da mistura e interesterificação química e enzimática de óleos e gorduras, gorduras trans-livre pode ser produzido. Mistura de gordura, foram formuladas por misturas ternárias de estearina de palma, uma gordura láurica (óleo de coco ou óleo de palmiste) e um óleo poliinsaturado (óleo de canola ou azeite de oliva) em diferentes proporções que foram interesterificadas. Neste trabalho, foram produzidos lipídios estruturados por interesterificação química e enzimática. A interesterificação química foi realizada nas seguintes condições: a 88 °C, 60 minutos de reação, 0,4% de catalisador metóxido de sódio, sob agitação e vácuo. A interesterificação enzimática, sendo realizada com duas lipases comerciais Thermomyces lanuginosa e Rhizomucor miehei, com seletividade sn-1,3. A interesterificação enzimática por batelada foi realizado seguindo um planejamento matriz central compósito rotativo em função da temperatura e da composição do meio, estearina de palma, óleo de palmiste e azeite de oliva e catalisado pelas lipases comerciais. O decréscimo do conteúdo de gordura sólida foi observado a 10 e 35 °C após a interesterificação. O biorreator contínuo foi operado nas seguintes condições: mistura de estearina de palma, óleo de palmiste, azeite de oliva (45:30:25), 10 gr de biocatalisador, 65 °C, com tempo de residência de 7 min e por 226 h para Thermomyces lanuginosa e 188 h para Rhizomucor miehei. A atividade do biocatalisador foi avaliada em termos da diminuição do conteúdo de gordura sólida a 35 °C, o qual é um parâmetro chave na produção de margarinas. O perfil de inativação do biocatalisador pode ser bem descrita pelo modelo de desativação de primeira ordem: meia-vida de 88 e 60 h foram estimados quando Thermomyces lanuginosa e Rhizomucor miehei, respectivamente, foram utilizados. Os óleos puros, as misturas originais e interesterificadas foram avaliados quanto à composição de ácidos graxos e triacilgliceróis, distribuição regioespecífica dos ácidos graxos nos triacilgliceróis, ponto de fusão e amolecimento, consistência, conteúdo de gordura sólida, comportamento de fusão e cristalização, estabilidade oxidativa, estrutura cristalina e polimorfismo. A interesterificação química e enzimática promoveram diminuição de triacilgliceróis trissaturados e triinsaturados e aumento dos monossaturados-diinsaturados e dissaturados-monoinsaturados, o que resultou no respectivo decréscimo dos pontos de fusão e amolecimento, consistência e conteúdo de gordura sólida, aumentando a plasticidade das gorduras. As curvas de fusão e cristalização das misturas foram modificadas pela alteração da composição dos triacilgliceróis pela interesterificação química e enzimática. Estabilidade térmica e a temperatura de oxidação da estearina de palma, óleo de coco e óleo de canola e suas misturas foram dependente da composição de ácidos graxos e independente da interesterificação química. Os resultados mostram que a interesterificação química e enzimática oferecem uma ferramenta útil para a concepção de gorduras com sintonizáveis propriedades físico-químicas, melhorando em relação a esse das gorduras de partida. / The consumer is becoming more aware of the relationship between diet and disease, which has driven the research on functional foods and their effects on the body. The role of fats and oils in human nutrition has been intensively studied and discussed for decades. It has been emphasized the importance of intake of omega-3, omega-6 and omega-9 fatty acids, reduction of saturated fatty acids and, more recently, control of intake of trans fatty acids. Through the blend and interesterification of oils and fats, trans-free fats can be produced. Fat blends, formulated by ternary blends of palm stearin, lauric fat (coconut oil and palm kernel oil) and polyunsaturated oils (canola oil and olive oil) were done in different ratios. In this work, were produced by chemical and enzymatic interesterification. Chemical interesterification was performed under the following conditions: at 88°C, 60 minutes reaction times, 0.4% sodium methoxide, under agitation and vacuum. For enzymatic interesterification being carried out with two commercial lipases Thermomyces lanuginosa e Rhizomucor miehei, with selectivity sn-1,3. Batch enzymatic interesterification were performed, following central composite rotatable designs (CCRDs) as a function temperature and media of palm stearin, palm kernel oil and olive oil formulation and catalyzed by a commercial immobilized lipase. A decrease in all SFC values of the blends at 10 °C and 35°C was observed upon interesterification. The bioreactor operated continuously: mixture of palm stearin, palm kernel oil and olive oil (45:30:25, wt %), at 65 °C, at a residence time of 7 min and for 226 h to Thermomyces lanuginosa and 188 h to Rhizomucor miehei.. Biocatalyst activity was evaluated in terms of the decrease of the solid fat content at 35 °C of the blends, which is a key parameter in margarine manufacture. The inactivation profile of the biocatalyst could be well described by the first-order deactivation model: Half-lives of 88 and 60 h were estimated when Thermomyces lanuginose and Rhizomucor miehei, respectively, were used. Pure oil, the original and interesterified blends were examined for fatty acids and triacylglycerols composition, regiospecific distribution of fatty acids in triacylglycerols, melting and softening points, consistency, solid fat content, thermal behavior, oxidation stability, crystalline microstructure and polymorphism. Chemical and enzymatic interesterification caused reduction of trisaturated and triunsaturated and increase in monosaturated-diunsaturated and disaturated-monounsaturated, lowering the initial melting and softening points, consistency and solid fat content, increasing plasticity of fats. Melting and crystallization curves were significantly modified by changing the composition of triacylglycerols by chemical and enzymatic interesterification. The thermal stability and oxidation temperature of palm stearin, coconut oil and canola oil and their blends were dependent on fatty acid composition and independent on chemical interesterification. The results show that the chemical and enzymatic interesterification provides a useful tool to design fats with tunable physicochemical properties, improved compared to that of the starting fats.

Les flavonoïdes glycosylés sont des métabolites secondaires d’origine végétale, qui présentent de nombreuses propriétés physico-chimiques et biologiques intéressantes pour des applications industrielles. La glycosylation accroît généralement la solubilité de ces flavonoïdes mais leurs faibles niveaux de production dans les plantes limitent leur disponibilité. Ces travaux de thèse portent donc sur le développement de nouvelles voies de gluco-diversification des flavonoïdes naturels, en mettant à profit l’ingénierie des protéines. Deux transglucosylases recombinantes, structurellement et biochimiquement caractérisées, l'amylosaccharase de Neisseria polysaccharea et la glucane-saccharase de branchement α-(1→2), forme tronquée de la dextran-saccharase de L. Mesenteroides NRRL B-1299, ont été sélectionnées pour la biosynthèse de nouveaux flavonoïdes, possédant des motifs originaux d’α-glycosylation, et potentiellement une solubilité accrue dans l'eau. Dans un premier temps, une librairie de petite taille de mutants de l’amylosaccharase, ciblée sur le site de liaison à l’accepteur, à été criblée en présence de saccharose (donneur d’unité glycosyl) et de lutéoline comme accepteur. Une méthode de screening a donc été développée, et a permis d’isoler des mutants améliorés pour la synthèse de nouveaux glucosides de lutéoline, jusqu’à 17000 fois plus soluble dans l’eau que la lutéoline aglycon. Afin de glucosyler d’autres flavonoïdes, la glucane-saccharase de branchement α-(1→2), a été préférentiellement sélectionnée. Des plans expérimentaux alliés à une méthodologie en surface de réponse ont été réalisés pour optimiser la production de l’enzyme sous forme soluble et éviter la formation de corps d’inclusion. Cinq paramètres ont été ainsi analysés : le temps de culture, la température, et les concentrations en glycérol, lactose (inducteur) et glucose (répresseur). En appliquant les conditions optimales prédites, 5740 U.L-1 de culture d’enzyme soluble ont été produites en microplaques, alors qu’aucune activité n’était retrouvée dans la fraction soluble, lors de l’utilisation de la méthode de production précédemment utilisée. Finalement, Une approche de modélisation moléculaire, structurellement guidés par l’arrimage de flavonoïdes monoglucosylés dans le site actif de l’enzyme, a permis d’identifier des cibles de mutagenèse et de générer des libraries de quelques milliers de variants. Une méthode rapide de criblage sur milieu solide, basée sur la visualisation colorimétrique d’un changement de pH, a été mise au point. Les mutants encore actifs sur saccharose ont été sélectionnés puis analysés sur leur capacités à glucosyler la quercétine et la diosmétine. Une petite série de 23 mutants a ainsi été retenue comme plate-forme d’enzymes améliorées dédiées à la glucosylation de flavonoïdes et a été évalués pour la glycosylation de six flavonoïdes distincts. La promiscuité, remarquablement générée dans cette plateforme, à permis d’isoler quelques mutants beaucoup plus efficaces que l’enzyme sauvage, produisant des motifs de glucosylation différents et fournissant des informations intéressante pour le design et l’amélioration des outils enzymatiques de glucosylation des flavonoïdes. / Flavonoid glycosides are natural plant secondary metabolites exhibiting many physicochemical and biological properties. Glycosylation usually improves flavonoid solubility but access to flavonoid glycosides is limited by their low production levels in plants. In this thesis work, the focus was placed on the development of new glucodiversification routes of natural flavonoids by taking advantage of protein engineering. Two biochemically and structurally characterized recombinant transglucosylases, the amylosucrase from Neisseria polysaccharea and the α-(1→2) branching sucrase, a truncated form of the dextransucrase from L. Mesenteroides NRRL B-1299, were selected to attempt glucosylation of different flavonoids, synthesize new α-glucoside derivatives with original patterns of glucosylation and hopefully improved their water-solubility. First, a small-size library of amylosucrase variants showing mutations in their acceptor binding site was screened in the presence of sucrose (glucosyl donor) and luteolin acceptor. A screening procedure was developed. It allowed isolating several mutants improved for luteolin glucosylation and synthesizing of novel luteolin glucosides, which exhibited up to a 17,000-fold increase of solubility in water. To attempt glucosylation of other types of flavonoids, the α-(1→2) branching sucrase, naturally designed for acceptor reaction, was preferred. Experimental design and Response Surface Methodology were first used to optimize the production of soluble enzyme and avoid inclusion body formation. Five parameters were included in the design: culture duration, temperature and concentrations of glycerol, lactose inducer and glucose repressor. Using the predicted optimal conditions, 5740 U. L-1of culture of soluble enzyme were obtained in microtiter plates, while no activity was obtained in the soluble fraction when using the previously reported method of production. A structurally-guided approach, based on flavonoids monoglucosides docking in the enzyme active site, was then applied to identify mutagenesis targets and generate libraries of several thousand variants. They were screened using a rapid pH-based screening assay, implemented for this purpose. This allowed sorting out mutants still active on sucrose that were subsequently assayed for both quercetin and diosmetin glucosylation. A small set of 23 variants, constituting a platform of enzymes improved for the glucosylation of these two flavonoids was retained and evaluated for the glucosylation of a six distinct flavonoids. Remarkably, the promiscuity generated in this platform allowed isolating several variants much more efficient than the wild-type enzyme. They produced different glucosylation patterns, and provided valuable information to further design and improve flavonoid glucosylation enzymatic tools.

No description available.

La demande croissante en carburants, ainsi que les changements climatiques dus au réchauffement planétaire poussent le monde entier à chercher des sources d’énergie capables de produire des combustibles alternatifs aux combustibles fossiles. Durant les dernières années, plusieurs sources potentielles ont été identifiées, les premières à être considérées sont les plantes oléagineuses comme source de biocarburant, cependant l’utilisation de végétaux ou d’huiles végétales ayant un lien avec l’alimentation humaine peut engendrer une hausse des prix des denrées alimentaires, sans oublier les questions éthiques qui s’imposent. De plus, l'usage des huiles non comestibles comme sources de biocarburants, comme l’huile de jatropha, de graines de tabac ou de jojoba, révèle un problème de manque de terre arable ce qui oblige à réduire les terres cultivables de l'industrie agricole et alimentaire au profit des cultures non comestibles. Dans ce contexte, l'utilisation de microorganismes aquatiques, tels que les microalgues comme substrats pour la production de biocarburant semble être une meilleure solution. Les microalgues sont faciles à cultiver et peuvent croitre avec peu ou pas d'entretien. Elles peuvent ainsi se développer dans des eaux douces, saumâtres ou salées de même que dans les terres non cultivables. Le rendement en lipide peut être largement supérieur aux autres sources de biocarburant potentiel, sans oublier qu’elles ne sont pas comestibles et sans aucun impact sur l'industrie alimentaire. De plus, la culture intensive de microalgues pour la production de biodiesel pourrait également jouer un rôle important dans l'atténuation des émissions de CO2. Dans le cache de ce travail, nous avons isolé et identifié morphologiquement des espèces de microalgues natives du Québec, pour ensuite examiner et mesurer leur potentiel de production de lipides (biodiesel). L’échantillonnage fut réalisé dans trois régions différentes du Québec: la région de Montréal, la gaspésie et le nord du Québec, et dans des eaux douces, saumâtres ou salées. Cent souches ont été isolées à partir de la région de Montréal, caractérisées et sélectionnées selon la teneur en lipides et leur élimination des nutriments dans les eaux usées à des températures différentes (10 ± 2°C et 22 ± 2°C). Les espèces ayant une production potentiellement élevée en lipides ont été sélectionnées. L’utilisation des eaux usées, comme milieu de culture, diminue le coût de production du biocarburant et sert en même temps d'outil pour le traitement des eaux usées. Nous avons comparé la biomasse et le rendement en lipides des souches cultivées dans une eau usée par apport à ceux dans un milieu synthétique, pour finalement identifié un certain nombre d'isolats ayant montré une bonne croissance à 10°C, voir une teneur élevée en lipides (allant de 20% à 45% du poids sec) ou une grande capacité d'élimination de nutriment (>97% d'élimination). De plus, nous avons caractérisé l'une des souches intéressantes ayant montré une production en lipides et une biomasse élevée, soit la microalgue Chlorella sp. PCH90. Isolée au Québec, sa phylogénie moléculaire a été établie et les études sur la production de lipides en fonction de la concentration initiale de nitrate, phosphate et chlorure de sodium ont été réalisées en utilisant de la méthodologie des surfaces de réponse. Dans les conditions appropriées, cette microalgue pourrait produire jusqu'à 36% de lipides et croitre à la fois dans un milieu synthétique et un milieu issu d'un flux secondaire de traitement des eaux usées, et cela à 22°C ou 10°C. Ainsi, on peut conclure que cette souche est prometteuse pour poursuivre le développement en tant que productrice potentielle de biocarburants dans des conditions climatiques locales. / The continuing increase in fuel demands, the dramatic situation in climate changes and the global warming are bringing the worldwide attention to the identification of alternative energy source for the production of combustibles that can replace fossil fuel. In last years, a lot of potential sources have been identified: the first potential biofuel feedstock that have been evaluated were oleaginous plants, but the utilization of vegetable, or vegetable oils, that may also be used for human feeding, could lead to the increase of food-grade oils costs and also generate ethic questions. Nevertheless, also using as biofuel sources not-edible oils, like oils from jatropha, tobacco seed or jojoba, the common problem for both edible and not-edible crops is the need to subtract arable land from agriculture and food industry. In this context, the utilization of aquatic microorganisms like microalgae as substrate for the production of biofuel seems to be the better solution. Microalgae are easy to cultivate and can grow with little or no attention, they can grow in fresh, brackish or salt water and in non-arable lands, moreover they are not edible with no consequences on food industry, and the oil productivity, with respect to the other potential biofuel sources, can be much higher. In addition, the intensive cultivation of microalgae for biodiesel production could also play an important role in CO2 mitigation. In this study, we isolated and morphologically identified Québec native micro algal species, surveyed and screened their potential for lipid (biodiesel) production. The sampling efforts made in three different regions of Québec: Montreal area, Gaspesie and Northern of Quebec; on fresh, brackish or saline water. One hundred strains were isolated from the Montreal area, characterized and screened for their lipid content and wastewater nutrient removal under different temperatures (10±2 ºC and 22±2 ºC). The high potential lipid producing algal species were selected. The use of wastewater as a substrate media decreases the economic cost realted to the biofuel production from microalgae as well as an interesting tool for wastewater treatment. We compared the biomass and lipid productivity of these strains on wastewater to a synthetic medium and identified a number of isolates that showed good growth at 10 ºC, gave a high lipid content (ranging from 20% to 45% of dry weight) or a high capacity for nutrient removal (>97% removal). Furthermore, we characterized one of the interesting strains that revealed high lipid and biomass productivity, the novel microalga Chlorella sp. PCH90. Its molecular phylogeny was established and lipid production studies as a function of the initial concentrations of nitrate, phosphate, and sodium chloride were carried out using Response Surface Methodology. Under the appropriate conditions this microalga could produce up to 36% lipid and grew well in both synthetic medium and secondary effluent from a wastewater treatment plant at both 22°C and 10°C. Thus, this strain is promising for further development as a potential biofuels producer under local climatic conditions.

Los objetivos de la presente tesis fueron comparar el efecto de tres técnicas de cocción en varios vegetales y su selección para cada producto estudiado. Para ello, los trabajos realizados han considerado los cambios en las propiedades físico-químicas, nutricionales, sensoriales y la microestructura. Asimismo, como respuesta al reto de aplicar tratamientos equivalentes en firmeza con diferentes técnicas de cocción se ha propuesto una metodología que combina los diseños experimentales de superficie respuesta (RSM) con análisis instrumentales y sensoriales. Los tratamientos térmicos estudiados fueron la cocción tradicional (TC¿ agua hirviendo a 100 °C) junto con dos tratamientos que utilizan el vacío en el procesado: el cook-vide (CV¿ cocción a vacío continuo donde los alimentos están en contacto con agua hirviendo a baja presión) y el sous-vide (SV¿ cocción de alimentos previamente embolsados a vacío donde el alimento está separado del agua de cocción). Los vegetales objeto de estudio fueron la patata morada (Solanum tuberosum L. var. Vitelotte), la judía verde (Phaseolus vulgaris L. cv. Estefania), la zanahoria (Daucus carota L. cv. Nantesa) y la col lombarda (o repollo colorado) (Brassica oleracea convar. capitata var. capitata f. rubra). Considerando muestras con firmeza instrumental similar y las propiedades nutricionales y sensoriales (especialmente aroma y sabor), incluyendo la aceptación del consumidor, se recomienda la cocción SV para los vegetales estudiados, excepto para la zanahoria. En el caso de este vegetal el cocinado tradicional (100 °C) mantiene la aceptabilidad del consumidor y aumenta la extracción de los ß-carotenos por lo que se considera más recomendable que el SV. / Iborra Bernad, MDC. (2013). Comparison of vacuum treatments and traditional cooking in vegetables using instrumental and sensory analysis [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32953 / TESIS

In forensic chemistry, a quicker and more accurate analysis of a sample is always being pursued. Speedy analyses allow the analyst to provide quick turn-around times and potentially decrease back-logs that are known to be a problem in the field. Accurate analyses are paramount with the futures and lives of the accused potentially on the line. One of the most common methods of analysis in forensic chemistry laboratories is gas chromatography, chosen for the relative speed and efficiency afforded by this method. Two major routes were attempted to further improve on gas chromatography applications in forensic chemistry.<br> The first route was to decrease separation times for analysis of ignitable liquid residues by using micro-bore wall coated open-tubular columns. Micro-bore columns are much shorter and have higher separation efficiencies than the standard columns used in forensic chemistry, allowing for faster analysis times while maintaining the expected peak separation. Typical separation times for fire debris samples are between thirty minutes and one hour, the micro-bore columns were able to achieve equivalent performance in three minutes. The reduction in analysis time was demonstrated by analysis of ignitable liquid residues from simulated fire debris exemplars.<br> The second route looked at a relatively new detector for gas chromatography known as a vacuum ultraviolet (VUV) spectrophotometer. The VUV detector uses traditional UV and far-ultraviolet light to probe the pi and sigma bonds of the gas phase analytes as well as Rydberg traditions to produce spectra that are nearly unique to a compound. Thus far, the only spectra that were not discernable were from enantiomers, otherwise even diastereomers have been differentiated. The specificity attained with the VUV detector has achieved differentiation of compounds that mass spectrometry, the most common detection method for chromatography in forensic chemistry labs, has difficulty distinguishing. This specificity has been demonstrated herein by analyzing various classes of drugs of abuse and applicability to “real world” samples has been demonstrated by analysis of de-identified seized samples.<br>

Produced water is the largest waste product by volume in the oil industry and its treatment in onshore or offshore fields poses bigger and different challenges than what water engineers are used to encounter. Process to achieve reuse quality of this water is very expensive with many technical hurdles to overcome making the optimization of the treatment steps necessary. Electrocoagulation (EC) generates coagulants in-situ responsible for destabilizing oil droplets, suspended particles, and common pollutant in produced water. Furthermore, EC is a very efficient technology compared with traditional primary treatments used in the oil & gas industry and has several advantages such as: no hazardous chemical handling (which diminishes the risk of accident and logistic costs), high efficiency potential concerning boron removal, potential small footprint and less sludge generation. In this research, the treatment of produced water using EC was investigated in a practical manner for the oilfield to aim for a cleaner effluent for further processing and help to achieve a reuse quality. For this, an EC cell was designed using different parameters normally used in the literature to fit this scenario. After preliminary tests, the treatment time was set to 3 seconds. Response surface method (RSM) was employed to optimize the operating conditions for TOC removal on a broad quality of synthetic produced water while varying: salinity, initial oil concentration and initial pH. TOC was chosen to be the main response because of its importance in legislation and sensibility on the method. Furthermore, turbidity removal, change of pH value after EC in water with lack of buffer capacity, aluminum concentration and preliminary tests involving boron removal and influence of hydrogen carbonate were also studied. Real produced water was treated with EC to assess the optimum conditions obtained by the RSM showing the results were closely related. Finally, an estimation of volume required and operating cost for EC in the different types of produced water was made to assess how realistic it is for onshore and offshore applications.:ERKLÄRUNG DES PROMOVENDEN I ACKNOLEDGEMENT III ABSTRACT V TABLE OF CONTENT VII LIST OF FIGURES IX LIST OF TABLES X LIST OF EQUATIONS XII ABBREVIATIONS XIV 1. INTRODUCTION 1 2. PRODUCED WATER 6 2.1 Characterization of Oilfield Produced Water 6 2.2 Produced Water Management 10 2.2.1 Discharge and Regulations 10 2.2.2 Efforts on Reuse 11 2.2.3 Cost 14 3. PRODUCED WATER TREATMENT 17 3.1 Most Common Primary Treatment 17 3.1.1 Hydrocyclones 17 3.1.2 Flotation unit 18 3.2 Further Water Treatment Technologies 19 3.2.1 Membrane Process 19 3.2.1.1 Microfiltration 19 3.2.1.2 Ultrafiltration 21 3.2.1.3 Nanofiltration 23 3.2.1.4 Reverse Osmosis 24 3.2.1.5 Forward osmosis 24 3.2.2 Electrodialysis 25 3.2.3 Biological treatment 28 3.2.3.1 Aerobic and anaerobic process 28 3.2.3.2 Combining membrane and bio-reactor 29 3.2.4 Oxidative process 30 3.2.4.1 Oxidation process 30 3.2.4.2 Anodic oxidation 32 3.2.5 Thermal technology 34 3.2.5.1 Evaporation 34 3.2.5.2 Eutectic freeze crystallization 35 3.2.6 Adsorption and ion-exchange 36 3.3 Electrocoagulation 39 3.3.1 Colloidal Stability Theory 39 3.3.2 Theory of Electrocoagulation 40 3.3.3 Mechanism of Abatement of Impurities 44 3.3.4 Operational parameters and efficiency 49 4. MATERIALS AND METHODS 51 4.1 Analytical Techniques and Synthetic Solutions 51 4.1.1 Analytical Techniques 51 4.1.2 Synthetic Produced Water 51 4.2 Design of Experiment and Models 54 4.3 Experimental Protocol for EC 56 4 .4 Development of the new Electrocoagulation cell 57 4.5 Real Produced water 58 5. RESULTS AND DISCUSSION 59 5.1 Designing EC Cell Process 59 5.1.1 Computational Fluid Dynamics for EC manufacturing 59 5.2 Preliminary Experiments 61 5.2.1 TOC Removal and Residence Time Determination 61 5.2.2 Aluminum Concentration 64 5.3 Models Quality and Range of Validity 66 5.3.1 TOC Removal 66 5.3.2 Turbidity Removal 69 5.3.3 Final pH value 71 5.3.4 Ionic Strength and Interpolation for Different Salinities 73 5.3.5 Partial Conclusions 76 5.4 Evolution of the Final pH Value 78 5.5 Operation Region for Effective Treatment of Produced Water with EC 80 5.5.1 Produced Water with Low Salinity 80 Organic Compounds Removal 80 Turbidity Removal 83 5.5.2 Produced Water with Medium Salinity 84 Organic Compounds Removal 84 Turbidity Removal 86 5.5.3 Produced Water with High Salinity 87 Organic Compounds Removal 87 5.6 Influence of Hydrogen Carbonate 90 5.7 Real Produced water 91 5.8 Boron Removal 93 5.9 Estimation of the Size for EC in Full scale 94 5.10 Produced Water with Very Low Salinity and EC 95 5.11 Estimation of Operation Cost 96 6. CONCLUSION AND RECOMMENDATIONS 98 6.1 Conclusion 98 6.2 Recommendations for Future Work 101 Scale up on EC for upstream 101 Further processing and reuse 101 Online optimization for EC 101 Recommendations for any research related to upstream produced water 101 BIBLIOGRAPHY 102 APPENDIX A 117 APPENDIX B 120

A l’heure actuelle, les biocarburants renouvelables et qui ne nuit pas à l'environnement sont à l'étude intensive en raison de l'augmentation des problèmes de santé et de la diminution des combustibles fossiles. H2 est l'un des candidats les plus prometteurs en raison de ses caractéristiques uniques, telles que la densité d'énergie élevée et la génération faible ou inexistante de polluants. Une façon attrayante pour produire la H2 est par les bactéries photosynthétiques qui peuvent capter l'énergie lumineuse pour actionner la production H2 avec leur système de nitrogénase. L'objectif principal de cette étude était d'améliorer le rendement de H2 des bactéries photosynthétiques pourpres non sulfureuses utilisant une combinaison de génie métabolique et le plan des expériences. Une hypothèse est que le rendement en H2 pourrait être améliorée par la redirection de flux de cycle du Calvin-Benson-Bassham envers du système de nitrogénase qui catalyse la réduction des protons en H2. Ainsi, un PRK, phosphoribulose kinase, mutant « knock-out » de Rhodobacter capsulatus JP91 a été créé. L’analyse de la croissance sur des différentes sources de carbone a montré que ce mutant ne peut croître qu’avec l’acétate, sans toutefois produire d' H2. Un mutant spontané, YL1, a été récupéré qui a retenu l'cbbP (codant pour PRK) mutation d'origine, mais qui avait acquis la capacité de se développer sur le glucose et produire H2. Une étude de la production H2 sous différents niveaux d'éclairage a montré que le rendement d’YL1 était de 20-40% supérieure à la souche type sauvage JP91. Cependant, il n'y avait pas d'amélioration notable du taux de production de H2. Une étude cinétique a montré que la croissance et la production d'hydrogène sont fortement liées avec des électrons à partir du glucose principalement dirigés vers la production de H2 et la formation de la biomasse. Sous des intensités lumineuses faibles à intermédiaires, la production d'acides organiques est importante, ce qui suggère une nouvelle amélioration additionnel du rendement H2 pourrait être possible grâce à l'optimisation des processus. Dans une série d'expériences associées, un autre mutant spontané, YL2, qui a un phénotype similaire à YL1, a été testé pour la croissance dans un milieu contenant de l'ammonium. Les résultats ont montré que YL2 ne peut croître que avec de l'acétate comme source de carbone, encore une fois, sans produire de H2. Une incubation prolongée dans les milieux qui ne supportent pas la croissance de YL2 a permis l'isolement de deux mutants spontanés secondaires intéressants, YL3 et YL4. L'analyse par empreint du pied Western a montré que les deux souches ont, dans une gamme de concentrations d'ammonium, l'expression constitutive de la nitrogénase. Les génomes d’YL2, YL3 et YL4 ont été séquencés afin de trouver les mutations responsables de ce phénomène. Fait intéressant, les mutations de nifA1 et nifA2 ont été trouvés dans les deux YL3 et YL4. Il est probable qu'un changement conformationnel de NifA modifie l'interaction protéine-protéine entre NifA et PII protéines (telles que GlnB ou GlnK), lui permettant d'échapper à la régulation par l'ammonium, et donc d'être capable d'activer la transcription de la nitrogénase en présence d'ammonium. On ignore comment le nitrogénase synthétisé est capable de maintenir son activité parce qu’en théorie, il devrait également être soumis à une régulation post-traductionnelle par ammonium. Une autre preuve pourrait être obtenue par l'étude du transcriptome d’YL3 et YL4. Une première étude sur la production d’ H2 par YL3 et YL4 ont montré qu'ils sont capables d’une beaucoup plus grande production d'hydrogène que JP91 en milieu d'ammonium, qui ouvre la porte pour les études futures avec ces souches en utilisant des déchets contenant de l'ammonium en tant que substrats. Enfin, le reformage biologique de l'éthanol à H2 avec la bactérie photosynthétique, Rhodopseudomonas palustris CGA009 a été examiné. La production d'éthanol avec fermentation utilisant des ressources renouvelables microbiennes a été traitée comme une technique mature. Cependant, la plupart des études du reformage de l'éthanol à H2 se sont concentrés sur le reformage chimique à la vapeur, ce qui nécessite généralement une haute charge énergetique et résultats dans les émissions de gaz toxiques. Ainsi le reformage biologique de l'éthanol à H2 avec des bactéries photosynthétiques, qui peuvent capturer la lumière pour répondre aux besoins énergétiques de cette réaction, semble d’être plus prometteuse. Une étude précédente a démontré la production d'hydrogène à partir d'éthanol, toutefois, le rendement ou la durée de cette réaction n'a pas été examiné. Une analyse RSM (méthode de surface de réponse) a été réalisée dans laquelle les concentrations de trois facteurs principaux, l'intensité lumineuse, de l'éthanol et du glutamate ont été variés. Nos résultats ont montré que près de 2 moles de H2 peuvent être obtenus à partir d'une mole d'éthanol, 33% de ce qui est théoriquement possible. / Currently, renewable and environmentally friendly biofuels are under intensive study due to increasing health concerns and diminishing fossil fuels. H2 is one of the most promising candidates due to its unique characteristics, such as a high energy density and low to non-existent generation of pollutants. One attractive way to produce H2 is through photosynthetic bacteria which can capture light energy to drive H2 production with their nitrogenase system. The major aim of this study was to improve H2 yield of the purple non-sulfur photosynthetic bacteria using a combination of metabolic engineering and design of experiments. One hypothesis was that H2 yield could be improved by redirection of Calvin-Benson-Bassham cycle flux to the nitrogenase system which catalyzes the reduction of protons to H2. Thus, a PRK, phosphoribulose kinase, knock out mutant of Rhodobacter capsulatus JP91 was created. Analysis of growth with different carbon sources showed that this mutant could only grow in acetate medium without, however, producing any H2. A spontaneous mutant, YL1, was recovered which retained the original cbbP (encoding PRK) mutation, but which had gained the ability to grow on glucose and produce H2. A study of H2 production under different illumination levels showed that the yield of YL1 was 20-40% greater than the wild type JP91 strain. However, there was no appreciable improvement of the H2 production rate. A kinetic study showed that growth and hydrogen production are strongly linked with electrons from glucose being mostly directed to H2 production and biomass formation. Under low to intermediate light intensities, the production of organic acids was significant, suggesting further improvement of H2 yield is possible by process optimization. In a related series of experiments, another spontaneous mutant, YL2, which has a similar phenotype to YL1, was tested for growth in ammonium-containing media. The results showed that YL2 could only grow with acetate as carbon source, again, without producing any H2. Prolonged incubation in media not supporting growth of YL2 enabled the isolation of two interesting secondary spontaneous mutants, YL3 and YL4. Western blot analysis showed that both strains had constitutive nitrogenase expression under a range of ammonium concentrations. The genomes of YL2, YL3 and YL4 were sequenced in order to find the mutations responsible for this phenomenon. Interestingly, mutations of nifA1 and nifA2 were found in both YL3 and YL4. It is likely that a conformational change of NifA alters the protein-protein interaction between NifA and PII proteins (such as GlnB or GlnK), enabling it to escape regulation by ammonium and thus to be capable of activating nitrogenase transcription in the presence of ammonium. It is not clear how the synthesized nitrogenase is able to maintain its activity since in theory it should also be subject to posttranslational regulation by ammonium. Further evidence could be obtained by studying the transcriptome of YL3 and YL4. An initial study of H2 production by YL3 and YL4 showed that they are capable of much greater hydrogen production than JP91 in ammonium medium, which opens the door for future studies with these strains using ammonium-containing wastes as substrates. Finally, the biological reformation of ethanol to H2 with the photosynthetic bacterium, Rhodopseudomonas palustris CGA009 was examined. Ethanol production with microbial fermentation using renewable resources has been treated as a mature technique. However, most studies of the reformation of ethanol to H2 have focused on chemical steam reforming, which usually requires a high energy input and results in toxic gas emission. Thus biological reformation of ethanol to H2 with photosynthetic bacteria, which can capture light to meet the energy requirement of this reaction, seems to be more promising. A previous study had demonstrated hydrogen production from ethanol, however, the yield or the duration of this reaction were not examined. A RSM (response surface methodology) analysis was carried out in which three key factors, light intensity, ethanol and glutamate concentrations were varied. Our results showed that nearly 2 moles of H2 could be obtained from one mole of ethanol, 33% of what is theoretically possible.