Made available in DSpace on 2017-07-24T19:38:00Z (GMT). No. of bitstreams: 1 Marilei Casturina.pdf: 1682032 bytes, checksum: 153b370b1eb7a1287824bf96aa0d0d65 (MD5) Previous issue date: 2008-11-17 / In this work is to porphyrin free base, cationic, meso-tetrapyridylporphyrin, TMPyP,and porphyrin metal, anion, zinc (II)-meso-Tetrakis (4-sulfonatophenyl), ZnTPPS4, in order to assess its possible applications in photodynamic therapy (PDT). For both, were investigated by molecular spectroscopy and UV-Vis, some properties of these porphyrins, such as interaction with biomimetic models, the ability to aggregate in different proportions water/ethanol, the photo-bleaching before lighting the red LEDs and generation of singlet oxygen through the test of uric acid. Microbiological tests were also conducted with Artemia salina and the bacterium Escherichia coli, to assess the in vitro photodynamic action on these microorganisms. The spectral behavior of porphyrin ZnTPPS4 was estimated to be varying the pH of the solution of porphyrin in aqueous medium and acetate/phosphate in the presence and absence of surfactant SDS (anion), CTAB (cationic) and HPS (zwiterionic). Through this analysis, we found that the porphyrin spectral change due to changes in pH, occurred at pHs lower when the porphyrin found himself in the presence of surfactants CTAB and HPS, indicating that there was interaction between porphyrin/ micelle surfactant, mediated by hydrophobic and electrostatic interactions. The ability of aggregation was evaluated by adding the solution of the porphyrin mixtures water/ethanol in different proportions in order to analyze the spectral behavior of both porphyrins with the increase of water content. Through this analysis it was found the displacement of the Soret band for a wavelength smaller, and the decrease in absorbance intensity of the condition of 100% water, a fact that may be related to different coefficients of molar absorptivity of porphyrins in solvents used. The photobleaching was putting itself and ethanol aqueous solutions of porphyrin under lighting of LEDs red during a total period of 1 hour, and showed that both porphyrins do not fall apart before the light source used. As the generation of singlet oxygen conducted through the test of uric acid, found that the generation of this species is better in water than ethanol, probably because there is more molecular oxygen dissolved in the first solvent. The porphyrin TMPyP showed increased photodynamic activity (PA) that ZnTPPS4, due to higher absorption in the range of issuing LEDs employees. Regarding microbiological tests found that the highest viewing on A. salina mortality occurs in the presence of porphyrin and under illumination, indicating photodynamic action of porphyrins on the microorganism. The testing done with E. coli, it is further inhibit the growth of this microorganism colonies where they were treated with porphyrins and light, compared with the controls: I) under light and without porphyrin; II) in the presence of porphyrin and no light; III) in the absence of light and porphyrin. / Neste trabalho estudou-se a porfirina base livre, catiônica, meso-tetrakis(4-metilpiridil)porfirina, TMPyP e a porfirina metalada, aniônica, Zinco(II)-mesotetrakis(4-sulfonatofenil), ZnTPPS4, para avaliar suas possíveis aplicações em terapia fotodinâmica (TFD). Para tanto, foram investigadas através de espectroscopia molecular UV-Vis, a interação das referidas porfirinas com modelos biomiméticos, a capacidade de agregação em diferentes proporções água/etanol, o foto-branqueamento perante iluminação de LEDs vermelhos e a geração de oxigênio singlete através do teste do ácido úrico. Também foram realizados testes com a Artemia salina e com a bactéria Escherichia coli, a fim de avaliar a ação fotodinâmica in vitro sobre esses microrganismos. O comportamento espectral da porfirina ZnTPPS4, foi avaliado variando-se o pH da solução de porfirina em meio aquoso e em acetato/fosfato na presença e na ausência dos surfactantes SDS (aniônico), CTAB (catiônico) e HPS (zwiteriônico). Através dessa análise, verificou-se que a mudança espectral da porfirina em decorrência da variação de pH, ocorreu em pHs menores quando a porfirina encontrou-se na presença dos surfactantes CTAB e HPS, indicando que houve interação entre porfirina/micela de surfactante, mediada por interações hidrofóbicas e eletrostáticas. A capacidade de agregação foi avaliada, acrescentando solução das porfirinas a misturas água/etanol de diferentes proporções, a fim de analisar o comportamento espectral de ambas as porfirinas com o aumento do teor de água. Através dessa análise verificou-se o deslocamento da banda Soret para comprimentos de onda menores, bem como, a diminuição da intensidade da absorbância em condição de 100% de água, fato que pode estar relacionado aos diferentes valores de coeficiente de absortividade molar das porfirinas nos solventes utilizados. A análise de foto-branqueamento foi realizado colocando-se soluções aquosas e etanólicas de porfirina sob iluminação de LEDs vermelhos durante um período total de 1 hora, e mostrou que ambas as porfirinas não se decompõem perante a fonte de luz empregada. Quanto a geração de oxigênio singlete realizado através do teste do ácido úrico, verificou-se que a geração dessa espécie é melhor em água que etanol. A porfirina TMPyP mostrou maior atividade fotodinâmica (AF) que a ZnTPPS4, por possuir maior absorção na faixa de emissão dos LEDs empregados. Em relação aos testes microbiológicos verificou-se que o maior índice de mortalidade sobre A. salina ocorre na presença das porfirina e sob iluminação, indicando ação fotodinâmica das porfirinas sobre esse microrganismo. No teste feito com a E. coli, evidenciou-se maior inibição no crescimento das colônias desse microrganismo quando as mesmas foram tratadas com porfirinas e luz, em comparação com os controles: I) sob luz e sem porfirina; II) na presença de porfirina e sem luz; III) na ausência de luz e porfirina.

Este trabalho apresenta a síntese de novos compostos fotoativos contendo os grupos uréia e tiouréia e suas potenciais aplicações como sensores de ânions. Os compostos sintetizados foram caracterizados pelas técnicas de FTIR, RMN de 1H e 13C, onde foi possível confirmar obtenção dos compostos. Os compostos obtidos apresentam absorção na região do ultravioleta com valores de extinção molar de acordo com as transições -*. Com objetivo de testar os novos compostos sintetizados como sensor de ânions foi realizado um estudo fotofísico na presença de diferentes ânions, sendo todos como sais de tetrabutilamônio. Esses testes também foram realizados utilizando o método de detecção visual e a espectroscopia de RMN 1H indicando que os compostos 32 e 33 apresentaram resposta colorimétrica após a adição de fluoreto. / This work presents the synthesis of novel photoactive compounds containing the urea and thiourea groups and its potential application as sensors for anions in solution. The synthesized compounds were characterized by FTIR, 1H and 13C NMR techniques. The compounds show absorption in the ultraviolet region with values of molar extinction accordingly to -* electronic transitions. In order to test the new compounds as optical sensors for anions, photophysical studies, as well as the method of visual detection and 1H NMR titration were performed in the presence of different anions as tetrabutylammonium salts. Fluoride could be successfully detected by UVVis and 1H NMR titration using compounds 32 and 33.

The replacement of artificial with natural dyes is one of the most challenging research fields in the food production area. Recent studies have shown that some frequently used synthetic colours, called the “Southampton 6 Colours” may be linked with hyperactivity in children. The purpose of this work is to analyse the degradation behaviour of black carrot, a natural, red dye commonly used for colouring food products, and subsequently improve its stability during heat and storage conditions. The stability of the black carrot mixture to heat exposure was investigated at a range of pH values by heat-treating aqueous solutions in a domestic oven at around 180oC to maintain the temperature at 100oC and the powdered material in a furnace at 180oC (typical baking conditions). 1H NMR (800 MHz) spectroscopy was used for the assignment of the aromatic chemical shifts of the black carrot mixture by overlaying them with the characterised 1H NMR chemical shifts of the individual components separated by RP-HPLC. Integration of high-resolution 1H NMR (800 MHz) spectra was used to follow the relative degradation of each of the components. Different procedures for the complexation of black carrot with metal oxides were developed, for which colourants of different colour shades were prepared. Spectroscopic techniques were used to follow the degradation of the complexes which were heat-treated at 180oC. Nano-scale investigation of the metal oxide powders was also carried out. The optimised colourants were tested on a bench scale and subsequently on an industrial scale in food pilot procedures. The successful complexes produced were found to be more heat stable compared to the commercial black carrot dye. The developed technologies are cheap and easy-to-produce methods to create intense heat and storage stable coloured pigments which can be used for the replacement of existing artificial dyes during food processing.

The objective of this diploma thesis is to analyze the visa policy of the European Union and its impact on tourism with the focus on differences in visa requirements of concrete member states of the European Union and the selected states outside of the European Union, which considerably affect tourism in the Czech Republic or considerably participate in outbound tourism of the Czech Republic. The submitted diploma thesis captures the current status of the visa policy of the European Union and compares visa policies of the Czech Republic and the remaining member states of the European Union with countries located outside of the European Union. A significant part of this diploma thesis are structured interviews with experts on the visa policy of the European Union in relation to tourism. The aim of this part is to compare different opinions of experts on tourism and the visa policy. This diploma thesis is divided into five main parts, which are further divided into individual subsections.

Les procédés industriels de transformation des grandes productions végétales génèrent des quantités importantes de coproduits qui peuvent très souvent trouver une valorisation en tant que sources de molécules à valeur ajoutée pour l'agrochimie. Les travaux de thèse se polarisent sur une matière première originale : le chanvre (Cannabis sativa L.), plante riche en une lignine particulière, de caractéristiques différentes de celle du bois et beaucoup plus accessible. Le procédé de défibrage du chanvre (Cannabis sativa L.) génère 30% de fibres pour 70% de co-produits lignocellulosiques : chènevotte (50%) et poudre organique (20%) lesquels ont été étudiés ici comme sources potentielles d'acides hydroxycinnamiques (AHC) tels que les acides férulique (AF) et p-coumarique (ApC). Leur répartition structurale dans la matrice lignocellulosique a été évaluée analytiquement par hydrolyses séquencées. L'AF est majoritairement éthérifié à la structure lignocellulosique, et ce pour les deux matières, tandis que l'ApC est principalement sous forme estérifiée dans la poudre organique et lie en proportions équivalentes par des liaisons ester et éther dans la chènevotte. Le fractionnement des coproduits du chanvre pour l'obtention d'extraits et raffinats performants en acides phénoliques a été étudié par extraction assistée par micro-ondes et extraction thermo-mécano-chimique en extrudeur bi-vis. Ces méthodes ont toutes deux permis d'intensifier l'extraction des AHC. Pour la chènevotte, un solvant hydro-alcoolique alcalin conduit aux rendements optimaux en ApC en réacteur micro-ondes et en AF par extrusion bi-vis tandis que, pour la poudre organique, ce même solvant est le plus efficace pour extraire les deux acides phénoliques par extrusion bi-vis. L'enrichissement en AHC des extraits par adsorption sur différents solides microporeux a été étudié. La zéolithe *BEA (beta) a démontré un fort potentiel tant pour l'adsorption d'AHC de solutions modèles que pour ceux contenus dans les extraits issus des schémas de fractionnement. / The industrial transformation of common cultivated crops generates significant amounts of by-products that can often be valorized as a source of value- added molecules for biochemistry. The present work focuses on an original raw material: hemp (Cannabis sativa L.), rich in a particularly, more accessible, lignin having different characteristics than that of wood. Hemp defibering process (Cannabis sativa L.) generates 30% fibers and 70% lignocellulosic by-products: hemp shives (50%) and hemp dust (20%) which were studied in this work as a potential source of hydroxycinnamic acids (HCA) such as ferulic (FA) and p-coumaric (pCA) acids. Their structural distribution in the lignocellulosic matrix was analytically evaluated by multistage hydrolysis. FA is mostly etherified to the lignocellulosic structure, while pCA is mainly esterified in hemp dust and equally bound through ester and ether linkages in hemp shives. Biorefinery of hemp by-products, to obtain extracts and raffinates which are rich in phenolic acids, was studied by using microwave-assisted extraction and thermo-mechano-chemical extraction using twin-screw extruder. Both methods have helped to intensify the extraction of HCA. For hemp shives, alkaline-hydro alcoholic solvent lead to the optimum yields of pCA by microwave extraction and of FA by twin-screw extrusion, while for hemp dust, the same solvent is the most effective for the extraction of both phenolic acids using twin-screw extraction. The enrichment of HCA extracts by adsorption on different microporous solids has been investigated. The zeolite *BEA (beta) showed a high potential of HCA adsorption from both model solutions and extracts obtained from fractionation.

Submitted by PPG Letras (letraspg@pucrs.br) on 2018-10-09T17:40:34Z No. of bitstreams: 1 Tese Danieli dos Santos Pimentel.pdf: 4896329 bytes, checksum: 8fbcf34615980e06f38eda3d7a624cee (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-10-10T11:51:49Z (GMT) No. of bitstreams: 1 Tese Danieli dos Santos Pimentel.pdf: 4896329 bytes, checksum: 8fbcf34615980e06f38eda3d7a624cee (MD5) / Made available in DSpace on 2018-10-10T12:12:57Z (GMT). No. of bitstreams: 1 Tese Danieli dos Santos Pimentel.pdf: 4896329 bytes, checksum: 8fbcf34615980e06f38eda3d7a624cee (MD5) Previous issue date: 2018-03-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This thesis studies the poetics of transcreation in the editions of A asa e a serpente [The Wing and the Serpent] (1979; 1980; 1988; and 2004), from Brazilian writer Vicente Cecim, with the objective of analyzing, from a comparison of the books, how the author?s literary work is carried by the glance of the (in)visible ink. First, it is created a route of the main aspects of the author?s trajectory, in addition to his relationship with contemporary Brazilian literature. In regard to critical reception of his work, diverse opinions are listed based on records present in the initial publication of A asa e a serpente (1979), passing through more specific analysis of Cecim?s creative universe. In conjunction, we discuss the literary composition of Andara?s cycle, which has as vertices, among others, reflections involving the Being and the perception of (in)visible worlds; the imagery of the labyrinth, as an imaginary space and a metalanguage of Vicente Cecim?s writing; the unfinishedness of literary writing itself and silence as a space opened to the creative imagination. In the chapter on theoretical foundation, an explanation is provided on what is the transcreation poetics through the logic of the writer himself, and how that concept suggests means for analyzing the different editions of A asa e a serpente. Lastly, it is outlined a comparison of the editions, resulting in the conclusion that Vicente Cecim delineates a transcreative writing approach centered between the visible and the invisible, culminating in oscillations which become perceptive trough changes in the writing plane and in the graphic project of the books. / Cette th?se ?tudie la po?tique de la transcr?ation dans les diff?rentes ?ditions du livre A asa e a serpente (1979, 1980, 1988 et 2004), de l??crivain br?silien Vicente Cecim. L?objectif est d?analyser, ? partir de la comparaison entre les ?ditions, comment se construit l??criture litt?raire de l?auteur par le biais de l?encre (in)visible. Dans un premier temps, on pr?sente un parcours des principaux aspects de la trajectoire de l?auteur, et aussi de sa relation avec la litt?rature br?silienne contemporaine. En ce qui concerne la r?ception critique de son oeuvre, on rassemble des opinions diverses bas?es sur des registres pr?sents dans la premi?re publication de A asa e a serpente (1979), en passant par des analyses plus sp?cifiques l?univers cr?atif de Cecim. De plus, on d?veloppe une ?tude de la composition litt?raire du cycle de Andara, qui a comme vecteurs, entre autres, des r?flexions au sujet de l??tre et des perceptions de mondes (in)visibles, l?image du labyrinthe comme espace imaginaire et du m?talangage de l??criture de Vicente Cecim, l?inachev? de l??criture litt?raire et le silence comme espace ouvert ? l?imagination cr?ative. Dans le chapitre de fondation, on explique ce qu?est la po?tique de la transcr?ation par la logique de l??crivain lui-m?me, et comment ce concept sugg?re les moyens d?analyser les diff?rentes ?ditions de A asa e a serpente. En dernier point, on ?bauche une comparaison entre les ?ditions, ce qui aboutit ? la conclusion selon laquelle Vicente Cecim ?bauche une ?criture transcr?ative qui est centr?e entre le visible et l?invisible. Ceci d?clenche des oscillations qui sont perceptibles ? travers les changements de plan de l??criture et dans le projet graphique des livres. / A presente tese estuda a po?tica da transcria??o nas edi??es de A asa e a serpente (1979, 1980, 1988 e 2004), de autoria do escritor brasileiro Vicente Cecim, com o objetivo de analisar, a partir do cotejo entre os livros, como se exerce a escritura liter?ria do autor pelo vi?s da tinta (in)vis?vel. Primeiramente, cria-se um percurso sobre os principais aspectos da trajet?ria do autor, al?m de sua rela??o com a literatura brasileira contempor?nea. No que diz respeito ? recep??o cr?tica de sua obra, elencam-se opini?es diversas com base em registros presentes na publica??o inicial de A asa e a serpente (1979), perpassando por an?lises mais espec?ficas acerca do universo criativo ceciniano. Aliado a isso, discorre-se a respeito da composi??o liter?ria do ciclo de Andara, que tem como v?rtices, dentre outros, reflex?es que envolvem o Ser e as percep??es de mundos (in)vis?veis; a imagem do labirinto, enquanto espa?o imagin?rio e metalinguagem da escrita de Vicente Cecim; o inacabamento da pr?pria escrita liter?ria e o sil?ncio como espa?o aberto ? imagina??o criadora. No cap?tulo de fundamenta??o, explica-se o que ? a po?tica da transcria??o pela l?gica do pr?prio escritor, e de como esse conceito sugere meios de analisar as diferentes edi??es de A asa e a serpente. E, por ?ltimo, delineia-se um cotejo entre as edi??es e A asa e a serpente, que resulta na conclus?o de que Vicente Cecim concebe uma escrita transcriativa que se centra entre o vis?vel e o invis?vel, culminando em oscila??es que s?o percept?veis atrav?s de mudan?as no plano da escrita e no projeto gr?fico dos livros

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-21T16:56:59Z No. of bitstreams: 1 2013 - Gustavo Orsolon de Souza.pdf: 1964014 bytes, checksum: 0f5bc73da7a42045227252ba6535baab (MD5) / Made available in DSpace on 2018-11-21T16:56:59Z (GMT). No. of bitstreams: 1 2013 - Gustavo Orsolon de Souza.pdf: 1964014 bytes, checksum: 0f5bc73da7a42045227252ba6535baab (MD5) Previous issue date: 2013-11-01 / CAPES / The main purpose of this work is the accomplishment of a study on intellectual history, giving priority to a comparative analysis of the four editions of the book ?Rebeli?es da Senzala?, paying more attention to the first and the second ones, our intent here is, first, focusing on the memorial of Cl?vis Moura, observing the process related to the production and publication of the first edition of the book ?Rebeli?es da Senzala?. Next, we will focus on the re-editions of the book. On that context, we will analyse the most important changes that took place on the second edition. We will examine how the introductory elements of the four editions such as, cover, edge and introduction gave a contribution to make the work of Cl?vis Moura up-to-date and attractive; and last but not less, we will analyse how the author, by means of a chapter of his book, constructed the image of a slave of action who takes part in the society during the slavery era. / O objetivo central dessa disserta??o ? realizar um estudo de hist?ria intelectual, priorizando a realiza??o de uma an?lise comparativa das quatro edi??es do livro ?Rebeli?es da Senzala?, concentrando-nos mais nas duas primeiras. Pretendemos, primeiramente, investir na mem?ria de Cl?vis Moura, observando o processo de produ??o e publica??o da primeira edi??o do livro ?Rebeli?es da Senzala?. Em seguida, o foco recair? nas reedi??es do livro. Nesse sentido, analisaremos as principais altera??es ocorridas na segunda edi??o; verificaremos como os elementos introdut?rios das quatro edi??es como, capa, ?orelha?, pref?cio e introdu??o contribuiram para tornar a obra de Cl?vis Moura atual e atraente; e, por fim, mas n?o menos importante, analisaremos, atrav?s de um cap?tulo do livro, como o autor construiu a imagem do escravo atuante e participativo na sociedade escravista.

Density Functional Theory (DFT) and time-dependent Density Functional Theory (TD-DFT) are powerful tools for modeling orbital energy in conjugated molecules and have been useful tools for research in organic photovoltaics. In this work, DFT is first used to explain the red shift in the absorption spectrum and increased absorption observed in MEH-PPV. Initially, the modeling of the red-shift in the absorption peak of MEH-PPV is studied using Gaussian 03 software with the global hybrid functional B3LYP for exchange-correlation and the 6-31G basis set. DFT and TD-DFT are used to separately study the effects of polymer chain length, carbon-carbon double-bond stretching, and the polymer in solution vs. in gas space on red shift in absorption spectrum. Next, Gaussian 09 software and the same B3LYP functional and 6-31G basis set are used to study interchain and intrachain interactions of MEH-PPV in solution. The red shift in the absorption peaks for three MEH-PPV configurations (single-chain pentamer, two stacked pentamers, and decamer) are compared with experimental results for five different solvents (chloroform, toluene, xylene, dichloromethane, and chlorobenzene). This investigation indicates that inter-chain interactions dominate in “good” aromatic solvents as compared to “poor” non-aromatic solvents. The results suggest that inter-chain charge transfer interactions play a critical role in real solutions and inter-chain aggregation takes precedence over intra-chain aggregation in aromatic solvents. In the final section of the study, accurate values for the range-separation parameter (w) for three lengths of MEH-PPV polymer (trimer, tetramer, and pentamer) in five different solvents (chloroform, chlorobenzene, xylene, Tetrahydrofuran, and dichloromethane) are reported using the range-separated functionals wB97XD and CAM-B3LYP. Using these data, range separation parameters are predicted and used for longer polymer chains in chloroform solution. The differences in the range separation parameters for the different solvents is statistically significant and gives further insight into the polymer/solvent interaction.

L’extrusion biocatalytique, ou bioextrusion, est une technique d’extrusion réactive utilisant des enzymes comme catalyseurs. Cette technique est considérée en temps qu’étape intermédiaire, subséquente au prétraitement physico-chimique et précédente à l’hydrolyse enzymatique enréacteur fermé. L’utilisation de l’extrusion permet un procédé continu, facilement modulable et adaptable à des conditions de hautes consistances, de nombreuses biomasses et facilement transférable à l’échelle industrielle. Néanmoins, les données bibliographiques font ressortir la complexité des entrants et leurs interactions lors de la bioextrusion de biomasses lignocellulosiques. Les conclusions des bioextrusions de biomasses amidonnées soulignent l’importance de l’étude de l’influence de la concentration en substrat et en enzymes. Les résultats obtenus à partir de la bioextrusion des biomasses lignocellulosiques valident l’existence d’une activité enzymatique en extrudeuse malgré la contrainte thermomécanique et le temps de séjour limité. Lors de cette étape, l’hydrolyse de la fraction cellulosique est favorisée pour des milieux concentrés en substrat et en enzymes. Des modifications significatives des fractions cellulosiques cristallines et amorphes en surface, des réductions des tailles de particules, une dégradation visuelle des structures de la biomasse et l’augmentation de la sensibilité à la décomposition thermique, sont aussi observées sur la fraction solide. L’hydrolyse enzymatique des bioextrudats est prolongée en réacteur fermé. La bioextrusion permet des améliorations significatives des taux et vitesses de conversion des sucres sur le long terme, jusqu’à 48 h. Les gains observés sont relativement constants pour la paille de blé et augmentent avec le temps pour les écorces de bouleau et les résidus de maïs. Post-extrusion, la concentration en substrat influence négativement la conversion des sucres. Cependant, les plus-values de conversion du glucose lié à la bioextrusion de paille de blé sont principalement observables pour des concentrations en substrat et en enzymes élevées. À partir de 4 h, des baisses significatives de la conversion du xylose sont observées après bioextrusion. Les déstructurations de la fraction solide, déjà observées au cours la bioextrusion, se poursuivent en réacteur fermé. Les meilleurs résultats hydrolytiques aux niveaux des hautes charges en enzymes et en substrat sont associables aux bonnes conditions de mélanges caractéristiques des éléments bilobes. L’ensemble enzymatique est probablement réparti de façon plus homogène (mélange distributif) pour cibler plus de sites disponibles. De plus, le mélangé dispersif limite la proximité entre enzymes de même type et les gênes associées. Le procédé d’extrusion permet une agitation efficace, un bon transfert de masse et probablement un meilleur contact entre enzymes et substrat. Les moins bons résultats de conversion du xylose sont probablement à relier à des phénomènes d’adsorption non-spécifique, ou encore de désactivation des hémicellulases, provoqués par l’intensité des contraintes thermomécaniques et les résidus ligneux. Les bons résultats de déstructuration après bioextrusionsont associables à une action synergétique des contraintes mécanique et biochimique. Les analyses d’autofluorescence montrent l’évolution de la fraction ligneuse dans le processus de déconstruction de la fraction solide. Une production progressive de particules très fines,visiblement associée à la fraction ligneuse, est observée. Des complexes lignine-carbohydratessont aussi détectés dans la fraction liquide. Etant peu, voire pas hydrolysable par voie enzymatique, ces fractions hétéropolymériques sont un frein à la déconstruction. Si la déstructuration des lignines est probablement majoritairement liée au prétraitement alcalin, le procédé de bioextrusion provoque une diminution de la teneur en hétéropolymères de plus hautes masses moléculaires. / Biocatalytic extrusion, also named bioextrusion, is a reactive extrusion technique using enzymes as catalysts. Bioextrusion is considered as a link between the previous physico-chemical pretreatment (like alkaline extrusion) and the subsequent enzymatic hydrolysis in batch conditions. The extrusion allows a continuous, flexible and versatile process for high consistency media, easily transferable to the industrial level. However, complexity of both lignocellulosic biomass and lignocellulolytic enzymes and their interactions during the extrusion process are underlined by the literature. Numerous response surface methodology experiments with starchy biomass indicate that bioextrusion efficiency is mainly influenced by substrate and enzymes loading. Enzymatic activity during the bioextrusion process of lignocellulosic biomass is confirmed by the experiments despite the mechanical constraints and the limited residence time. During bioextrusion, best holocellulosic fraction hydrolysis results were obtained with high substrate and enzymes loadings. Significant modifications of the solid fraction like particule size reduction, visual deconstruction of the biomass structure, increased sensibility to thermal decomposition and the evolution of the surface exposure of crystalline and amorphous cellulose were observed. Enzymatic hydrolysis of the bioextrdates is prolonged in batch conditions. Clear improvements of speeds and rates of sugars conversion up to 48 h indicate a long term influence of the bioextrusion. Gain observed are steady for the pretreated wheat straw whereas it increases with time for corn residues and birch barks. Post-extrusion, a negative influence of the substrate loading is measured. However, best enhancements for the glucose conversion of pretreated wheat straw are detected for high substrate and enzymes loadings. From 4 to 48 h, significant losses in xylose conversion are measured with previous bioextrusion. Indicators of the solid fraction deconstruction, observed during the bioextrusion step, indicate a stronger biomass degradation after 48 h. Improvements of glucose conversion rates can be associated with good mixing conditions of the extruder, especially due to the use of kneading elements. Enzymes are probably more homogeneously distributed (distributive mixing) and can access more catalytic sites available. Moreover, dispersive mixing limits the enzyme jamming due to the biocatalysts concentration. Extrusion process permits an better agitation efficiency, good mass transfer conditions and probably a higher contact between substrate and enzymes. Lower xylose conversion results may be attributed to non-specific adsorptions or inactivation phenomena due to mechanical constraints and lignin residues. Good deconstruction results on the solid fraction may be associable with a synergetic action between mechanical and biochemical constraints. Autofluorescent signal analysis of the lignin fraction show its evolution during the deconstruction of the solid residue. During the hydrolysis, a progressive production of very small particles, appearing to be associated with the lignin fraction is observed. Lignin-carbohydrate complexes are also detected in the liquid fraction. These heteropolymeric complexes, difficult or even impossible for the enzymes to hydrolyze, are an obstacle to the biomass valorization. If lignin deconstruction is mainly due to the alkaline pretreatment, bioextrusion process seems to reduce the proportion of these heteropylymers with high molecular weights.

The main aim of this thesis work is to investigate the electrical, optical and thermal impact characteristics of cobalt oxide doped antimony tin oxide (CoO-ATO) in the form of thin films and nanofiber membranes. CoO-ATO is a novel composite material that has the potential to be used as reinforced aircraft coatings, military garment coatings, or more specifically as an anti-reflective (AR) top coating for photovoltaic (PV) cells. This work will be critical in determining the effectiveness of using a CoO-ATO layer in these applications. Electrospun nanofibers and spin coated thin films consisting of a polymeric solution of CoO-ATO will be used. Thin films are created using spin coating techniques, and nanofiber membranes are created using an electrospinning technique. Polystyrene (PS) will be used as a solute, and chloroform as a solvent, to create the solution. It is hypothesized that coatings of this material will have improved optical characteristics as compared to traditional ATO coatings and minimum impact from thermal cycling making it a favorable candidate for PV cells. This work will do an electrical, optical and thermal cycling impact characterization of CoO-ATO thin films and nanofiber membranes for a doping range of x% CoO where x ranged from 0.2