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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.
91

De l'intention à la solution architecturale : proposition d'une méthode d'assistance à la prise en compte de la lumière naturelle durant les phases amont de conception / From intention to architectural solution : The proposal of a support method to integrate daylight during the early design steps

Gallas, Mohamed-Anis 06 September 2013 (has links)
La lumière naturelle éclaire l'espace architectural créant les conditions nécessaires pour accueillir des activités humaines. La fonction d'éclairage de la lumière naturelle est associée à une autre dimension plus sensible attribuant une identité et une singularité à l'espace conçu. La maîtrise du comportement lumineux est une activité complexe qui fait appel à une multiplicité de facteurs dont la caractérisation est confrontée à l'incertitude et l'imprécision des informations disponibles durant les phases conceptuelles du projet. L'objectif de notre recherche est de proposer une méthode d'assistance qui prend en considération les propriétés des phases amont de conception pour aider le concepteur à intégrer ses intentions d'ambiance de lumière naturelle. Nous proposons une méthode d'assistance structurée selon un processus déclaratif permettant au concepteur d'expliciter ses intentions d'effets de lumière naturelle et de les traduire en solutions architecturales potentielles qu'il peut intégrer dans son projet. Cette méthode considère les intentions d'ambiance de lumière naturelle comme une information source à utiliser pour proposer une aide à la conception pendant les phases préliminaires du projet où elles constituent les seules informations disponibles. Cette méthode offre des fonctionnalités capables de gérer l'incertitude qui caractérise les phases de recherche et de formalisation d'idées. Notre méthode d'assistance a été implémentée dans un prototype d'outil dont l'apport cognitif et la capacité d'accompagnement des activités de conception ont été évalués et analysés dans un cadre expérimental de conception de projet / The daylight illuminates the architectural space and creates the necessary conditions to accommodate human activities. The illuminating function of daylight is joined to another sensitive dimension that attributes a distinctive identity to the designed space. The control of daylight in architectural environment needs some detailed and precise characteristics about aperture and walls features. The multiplicity of these characteristics is faced with the inaccuracy and the uncertainty of the design information available during the early steps. Our research aims to propose a design support method that takes into account the early design step features and helps designers to integrate there daylight atmosphere intentions in project. We propose a design support method structured as a declarative modelling process. The declarative process helps the designer to declare his daylight intentions and to translate them to potential solutions that could be integrated in his project. This method considers the designer intentions as the main design information used to help designer during the early design steps. The proposed method provides functionalities that could operate the inaccuracy and the uncertainty of the ideas research and formalisation steps. Our design support method was implemented in a prototype design support tool. The cognitive contribution and the ability to support the design activities of the proposed tool was evaluated and analysed in an experimental design context
92

A natureza de defeitos de Bulk e na superfície de semicondutores / The nature of defects in the Bulk and at the surface of semiconductors

Dalpian, Gustavo Martini 11 August 2003 (has links)
Utilizando métodos de primeiros princípios, baseados na Teoria do Funcional da Desidade, investigamos, de forma sistemática, problemas de interesse na física de semicondutores: (i) A liga SixGe1-x: observa-se um pequeno desvio da linearidade, para o parâmetro de rede da liga, em função da concentração, sendo que as distâncias entre átomos de Ge são as que mais variam. O comportamento de vacâncias nessa liga se mostrou intermediário entre o Ge e o Si, e a energia de formação (EF) das vacâncias variou entre 2,06 eV e 2,90 eV, dependendo da vizinhança dessa. Propusemos um modelo para a difusão de Ge nessa liga. O fato das vacâncias com mais átomos de Ge como vizinhos ter menor energia de formação, faz com que a difusão das vacâncias se dê por caminhos lembrando o Ge puro, ou seja, a tendência será de que os vizinhos dessa vacância sejam de Ge, para ligas ricas em Ge; (ii) Superfícies: estudamos a adsorção de monômeros e dímeros de Ge sobre Si (100). Verificamos que, para monômeros, podem existir diversos mínimos locais da superfície de energia potencial para a mesma posição (x, y) na superfície, cuja diferença está na inclinação dos dímeros da superfície perto deste átomo. Mostramos que isso pode ser identificado em imagens teóricas de STM (Scanning Tunelling Microscopy) e propomos que isso seja verificado experimentalmente. Este tipo de efeito também ocorre com dímeros, sendo que isso já foi observado experimentalmente, mas com uma interpretação errônea. Através do nosso estudo podemos propor uma estrutura mais condizente com as imagens experimentais. O comportamento de átomos e dímeros de Si e Ge perto de degraus também foi analisado. Devido à diferença no parâmetro de rede do Si e do Ge, mostramos que a adsorção se torna diferente quando somente dois átomos estão na superfície. Através desses resultados, propomos um modelo para explicar a reversão da rugosidade dos degraus durante o crescimento de Ge sobre Si(100); (iii) Impurezas de Mn em Si: analisamos o comportamento de impurezas de Mn no cristal de Si e sobre a superfície. No cristal, observamos que a EF de sítios intersticiais é menor do que os sítios substitucionais. Sobre a superfície, existe um sítio substitucional que possue a mesma EF de um sítio intersticial. Esse é um fato importante para o desenvolvimento de semicondutores ferromagnéticos à base de Si. Propomos um método para que esse fato seja verificado experimentalmente, através de imagens de STM. / Using ab initio methods, based on Density Functional Theory, we have systematically investigated problems of interest for semiconductor physics: (i)The SixGe1-x alloy: we observe a small bowing in the lattice parameter, as a function of concentration, and that a larger variation in interatomic distances occurs for Ge-Ge bonds. The behavior of vacancies in this alloy is intermediate between Si and Ge, with formation energies (EF) varying from 2,06 eV to 2,90 eV, depending on the neighborhood of the vacancy. We propose a model for the diffusion of Ge in this alloy. As the vacancy with four Ge atoms as first neighbors hás smaller formation energy, the diffusion of the vacancies Will take place along paths that resemble purê Ge, for Ge-rich alloys; (ii)Surfaces: we study the adsorption of Ge monomers and dimers on Si(100). For monomers, there are several local mínima of the potential energy surface, for the same (x, y) position in the surface, depending on the buckling of the surface dimers near the adatom. We show that this can be identified in theoretical STM (Scanning Tunelling Microscopy) images. This kind of effect also occurs for dimers, and hás already been observed experimentally, but with a wrong interpretation. Through our study, we propose a new structure for the experimental images. The behavior of Si and Ge atoms and dimers near steps is also analyzed. Due to the differencein the lattice parameter of Si and Ge, we show that the adsorption becomes different when only two atoms are in the surface. Through these results, we propose a model to explain the reversion of step roughness due to Ge deposition on Si(100); (iii)Mn impurities in Si: we analise the behavior of Mn impurities in bulk Si ando n the surface. For the bulk, we observe that EF is lower for intersititial than for substitutional sites. On the surface, there is a substitutional site that hás the same EF AS A INTESTITIAL ONE. This fact may be important to the development of Si based ferromagnetic semiconductors. A method is proposed to verify this fact experimentally, through STM images.
93

Méthodes de diagnostic des piles à combustible / Fuel cells diagnosis methods

Génevé, Thomas 01 February 2016 (has links)
La problématique développée dans cette thèse est le diagnostic des piles à combustible (PAC) de type « Proton Exchange Membrane » (PEM). Nous avons choisi d’axer ces travaux sur différentes méthodes de diagnostic, séparées en deux grandes thématiques, relativement différentes et donc indépendantes, qui forment les deux parties de cette thèse. Dans la première partie, intitulée « Méthodes de diagnostic des fuites internes », nous nous focaliserons sur un type de dégradation des PAC, celle de la membrane, et de sa conséquence principale, l’augmentation des fuites internes. Après avoir fait l’inventaire des différentes techniques de diagnostic possibles, nous avons eu l’opportunité d’en tester certaines sur un stack (empilement de cellules élémentaires) dégradé dont nous disposions. La voltammétrie cyclique semble la plus intéressante en terme de précision. Cependant, pour le diagnostic complet d’un stack, le niveau de fuite de chaque cellule doit être évalué. Il apparaît que cette opération est extrêmement chronophage ; nous avons donc dû mettre au point des méthodes alternatives à celles rencontrées fréquemment dans la littérature. Nous avons d’une part appliqué la voltammétrie cyclique directement aux bornes du stack et parallèlement nous avons mis au point une technique nouvelle de diagnostic des fuites internes d’une PAC. Ces méthodes seront testées sur trois stacks comportant chacun un nombre différent de cellules. La deuxième partie de ce manuscrit est intitulée « Méthodes de diagnostic en gaz actifs ». Nous aborderons dans un premier temps une méthode bien connue, la Spectroscopie d’Impédance Electrochimique (SIE). L’utilisation de cette technique soulève deux problématiques : le choix d’un modèle approprié pour décrire des phénomènes physico-chimiques variés puis la difficulté de converger vers un jeu unique de paramètres une fois le modèle établi. Partant de ce constat, nous avons développé une technique originale d’exploitation des SIE, basée sur un modèle électrique sans a priori, dont la construction va se faire automatiquement étape par étape. Cet algorithme sera validé de manière théorique sur des simulations, puis nous confirmerons son potentiel sur des données expérimentales issues d’essais de vieillissement de monocellules. Parallèlement, nous avons développé une technique alternative à la spectroscopie d’impédance, basée sur l’exploitation d’échelons de courant. Cette méthode permet d’extraire un spectre de constantes de temps sans passer par de l’identification paramétrique. Après une première validation théorique grâce à des simulations, nous avons éprouvé cette technique avec d’une part les données de vieillissement mentionnées précédemment ainsi qu’avec des données issues d’un essai d’engorgement d’une monocellule. Nous confirmerons que cette technique est bien adaptée pour effectuer du diagnostic en cours de fonctionnement. / This thesis deals with Proton Exchange Membrane Fuel Cell (PEMFC) diagnosis. Several methods will be treated, that have been divided into two main issues. These issues are quite independent and constitute the two parts of the manuscript. The first part, entitled “internal leakage detection methods”, concerns a major fault in PEMFC: membrane permeation. The consequence is the increase of internal leakage, or crossover. First, several diagnosis techniques are listed, and some of them are tested on a faulty stack. Cyclic voltammetry seems to be a good choice, but needs a lot of time to be performed on a large scale stack. Indeed, to achieve a satisfying level of diagnosis, the crossover of every cell in the stack has to be evaluated. New diagnosis techniques are needed to shorten the test phase. Cyclic voltammetry is performed directly at the stack level, while concurrently a new method is investigated to measure all cell crossovers simultaneously. Validation is done by experiments on three different stacks with different numbers of cells. The second part is entitled “diagnosis methods with active gases”. In a first time the well-known Electrochemical Impedance Spectroscopy (EIS) technique has been used as a characterization tool. But two issues arise from the EIS use: the choice of an appropriate model that describes all the electrochemical phenomena and the difficulty to obtain a unique set of parameters after the fitting stage. To solve these issues, an algorithm has been developed. It is based on an electrical circuit model built automatically step by step, which does not require the knowledge of every phenomenon of the studied system. The algorithm is validated theoretically by numerical simulations and then by experimental data collected from ageing tests with single cells. Secondly, a method alternative to EIS has been investigated, based on the fuel cell voltage response to current steps. A time-constant spectrum can be extracted from this response without the need of parameter identification process. After a first validation thanks to numerical simulations, this algorithm has been tested with the ageing data previously mentioned and also with a flooding experiment performed on a single cell. The time-constant spectrum seems to be an appropriate tool for fuel cell online diagnosis.
94

Nelinearna dinamika u okviru Frenkel-Kontorova modela pod dejstvom spoljašnjih periodičnih sila / Nonlinear dynamics of ac + dcdriven Frenkel-Kontorova model

Mali Petar 27 September 2015 (has links)
<p>Ispitivan je generalisani Frenkel-Kontorova model pod&nbsp;dejstvom spolja&scaron;njih periodičnih sila,&nbsp;i njihov uticaj na &Scaron;apiro stepenike.&nbsp;Deformacija substratnog potencijala prouzrokuje&nbsp;pojavu velikih polucelih i drugih subharmonijskih&nbsp;stepenika u sistemu.&nbsp;Rezultati dobijeni u radu su od značaja&nbsp;u talasima i spinovima gustine naboja&nbsp;kao i u Džozefsonovim spojevima.</p> / <p>Properties of the Shapiro steps in dierent<br />commensurate structures of the ac + dc driven<br />Frenkel-Kontorova model with dierent generalized<br />substrate potential have been examined.<br />Deviation from the sinusoidal potential produces<br />appearance of large subharmonic steps.<br />Presented results could be of great importance<br />for thestudies of all real systems closely related<br />to the dissipative dynamics of the FK model<br />such as studies of the charge- or spin-density wave<br />systems and the systems of Josephson-junction arrays.</p>
95

Integração da produção de xilo-oligossacarídeos como co-produto de alto valor agregado ao processo de produção de celulose nanofibrilada a partir do bagaço de cana-de-açúcar / Integration of xylooligosaccharide production as a high-value co-product to the process of production of nanofibrillated cellulose from sugarcane bagasse

Marcondes, Wilian Fioreli 05 March 2018 (has links)
Neste trabalho, foram realizados pré-tratamentos para maximizar o fracionamento dos componentes da biomassa e alcançar uma alta valorização do material. Relatamos uma integração de etapas de pré-tratamentos obter três produtos de alto valor agregado em um conceito de biorrefinaria: xilooligosacarídeo (XOS), xilose e celulose nanofibrilhada (CNF). Foi estudada a maximização de valor da fração hemicelulosica do bagaço de cana-de-açúcar através de extração hidrotérmica, de preferência na forma de XOS, e também se avaliou a produção de CNF, um nanomaterial emergente com inúmeras aplicações em diversos setores, como papel, têxteis e eletrônicos. Para selecionar a melhor condição de solubilização de hemicelulose na forma de XOS, as condições do processo hidrotérmicos foram avaliadas com planejamento experimental estatístico 23, com rotação do tipo estrela, a fim de analisar o efeito combinado de temperatura, tempo e concentração de ácido (H2SO4). A melhor condição experimental para produzir XOS com alto rendimento e seletividade foi a 182 °C durante 5,5 minutos e sem adição de ácido, obtendo um hidrolisado com recuperação de 43 % da xilana inicial na forma de XOS e apenas 2 % na forma de xilose. Um segundo tratamento hidrotérmico foi realizado com o objetivo de remover a xilana residual do bagaço tratado, de preferência na forma de XOS. Devido à alta recalcitrância do material, não foi possível encontrar uma condição experimental para obter alta seletividade para XOS no segundo pré-tratamento e, portanto, foi escolhido obter um hidrolisado rico em xilose, um produto que também possui diversas aplicações. As melhores condições experimentais para se obter um hidrolisado rico em xilose foram determinadas a 168 ° C durante 5,5 minutos e 1,01% m/m de H2SO4, obtendo-se uma recuperação de 36 % da xilana presente inicialmente no bagaço na forma de xilose e apenas 3 % na forma de XOS, sendo este um processo altamente seletivo para recuperação da xilana na forma monomérica. A fração sólida oriunda das etapas de extração da xilana foi deslignificada com NaOH e branqueada em duas etapas, com H2O2 em meio alcalino e com NaClO2 em meio ácido, obtendo pasta celulósica com alto teor de celulose (88,9% m/m de celulose). A polpa celulósica foi processada em um refinador de disco mecânico (SupermassColloider) para produzir celulose nanofibrilada (CNF-B). As propriedades morfológicas do CNF-B foram avaliadas e verificou-se que foi semelhante à nanocelulose de polpa Kraft (CNF-K), em relação as suas dimensões, produzida nas mesmas condições. Além disso, a produção do CNF-B consumiu cerca de um terço da energia necessária para obter o CNF-K. O balanço de massa final do processo mostrou uma alta recuperação dos carboidratos originais em produtos de alto valor agregado. A recuperação da xilana foi de cerca de 88% m/m, sendo 43% m/m de XOS e 36% m/m de xilose. O alto conteúdo recuperado dos coprodutos demonstra a alta seletividade das otimizações realizadas. Por fim, o processo obteve alta recuperação e conversão de celulose à CNF-B, com um rendimento de 88% m/m. / A pretreatment has been pursued to maximize the biomass components and achieve a high material´s valorization. Here, we report an integration of pathways, which have been effective to obtain three high value-added products in a biorefinery concept: XOS, xylose and cellulose nanofibrillated (CNF). The maximization of hemicellulose fraction was studied through hydrothermal extraction from sugarcane bagasse, preferably oligosaccharides (XOS) form, and it was also evaluated CNF production, an emerging nanomaterial with numerous applications in diverse sectors such as paper, textiles and electronics. To select the best condition of hemicellulose solubilization in the form of XOS, the hydrothermal process conditions were evaluated with statistical experimental design to analyze the combined effect of temperature, time and acid concentration (H2SO4). The best experimental condition to produce XOS with high yield and selectivity was at 182 ° C for 5.5 minutes and without acid addition, obtaining a hydrolysate with 75% w/w of XOS content, which corresponds to 43% w/w of the original xylan. A second hydrothermal treatment was performed with the aim of remove a residual xylan from treated bagasse, focusing in XOS form. Because of the high susceptibility of the material, it was not possible to find an experimental condition to achieve high selectivity for XOS in the second pretreatment and, therefore, it was chosen to obtain a hydrolyzate rich in xylose, a product with many applications as well. The best experimental conditions to the hydrolyzate system based in xylose was determined at 168 ° C for 5.5 minutes and 1.01% w/w H2SO4, obtaining a xylose\'s yields of 36% w/w (initial xylan). The solid fraction of the second hydrothermal step was deslignificated with NaOH and bleached in two steps, with H2O2 at alkaline medium and with NaClO2 at acid medium, obtaining cellulosic pulp with high cellulose content (88.9% w/w of cellulose). Cellulosic pulp was processed in a mechanical disc refiner (SupermassColloider) to produce fibrillated nanocellulose (CNF-B). The morphological properties of the CNF-B were evaluated, and it was found to be similar to Kraft pulp nanocellulose (CNF-K) produced at same conditions. Besides that, the production of CNF-B consumed about one third of the energy required to obtain CNF-K. CNF-B and CNF-K were also compared in terms of mean diameter and it was obtained 56.72 nm and 36.83 nm, respectively. The final mass balance of the process showed a high recovery of the original carbohydrates in means of high value-added product. The recovery of xylan was around 88%, being 43% w/w of XOS and 36% w/w of xylose. The high content recovered of the co-products demonstrate the high selectivity of the optimizations performed. Thus, this resulted in a high recovery and conversion of cellulose in the CNF-B with a yield of 88% w/w.
96

Sistema gerenciador de documentação de projeto / A design trace management system

Soares, Sandro Neves January 1996 (has links)
A complexidade do projeto de sistemas eletrônicos, devido ao número de ferramentas envolvidas, ao grande volume de dados gerado e a natureza complicada destes dados, foi a causa principal do aparecimento, no final da década de 80, dos frameworks. Frameworks são plataformas que suportam o desenvolvimento de ambientes de projeto e que tem, como objetivo principal, liberar os projetistas das tarefas acessórias dentro do processo de projeto (como, por exemplo, a gerencia dos dados criados), possibilitando-lhes direcionar os esforços, exclusivamente, para a obtenção de melhores resultados, em menor tempo e a baixo custo. Para a realização deste objetivo, diversas técnicas são utilizadas na construção dos frameworks. Uma delas é conhecida como documentação dos passos de projeto. A documentação dos passos de projeto é um recurso utilizado para manter a história do projeto (usualmente, ferramentas executadas e dados gerados). Ela tem sido amplamente utilizada em trabalhos relacionados a frameworks. Porém, nenhum destes trabalhos aproveita toda a potencialidade do recurso. Alguns utilizam-no apenas nos serviços relacionados a gerencia de dados. Outros, utilizam-no apenas nos serviços relacionados a gerencia de projeto. A proposta deste trabalho, então, é a criação de um sistema que explore toda a potencialidade da documentação dos passos de projeto, disponibilizando, a partir daí, informações e serviços a outros sub-sistemas do framework, de forma a complementar a funcionalidade destes, tornando-os mais abrangentes e poderosos. / The VLSI design complexity, due to the number of involved tools, the enormous generated data volume and the complex nature of the data, was the main cause of the appearance of the frameworks in the end of the 80's. Frameworks are platforms that support the development of design environments and, as their main purpose, liberate the VLSI designers from the supplementary tasks in the design process, as the data management. It makes possible to direct efforts exclusively to obtaining better results, in shorter time and with lower costs. To this purpose, many techniques have been used in the implementation of frameworks. One of these techniques is known as design steps documentation. The design steps documentation is a resource used to keep the design history (usually, executed tools and generated data). It has been widely used in various frameworks. But none of them take full advantage of this resource. Some of them use the design steps documentation only in the data management services. Others, use it only in the design management services. So, the proposal of this work is to create a system that takes full advantage of the design steps documentation, providing information and services to other sub-systems of the framework to complement their functionality, making them more powerful.
97

Integração da produção de xilo-oligossacarídeos como co-produto de alto valor agregado ao processo de produção de celulose nanofibrilada a partir do bagaço de cana-de-açúcar / Integration of xylooligosaccharide production as a high-value co-product to the process of production of nanofibrillated cellulose from sugarcane bagasse

Wilian Fioreli Marcondes 05 March 2018 (has links)
Neste trabalho, foram realizados pré-tratamentos para maximizar o fracionamento dos componentes da biomassa e alcançar uma alta valorização do material. Relatamos uma integração de etapas de pré-tratamentos obter três produtos de alto valor agregado em um conceito de biorrefinaria: xilooligosacarídeo (XOS), xilose e celulose nanofibrilhada (CNF). Foi estudada a maximização de valor da fração hemicelulosica do bagaço de cana-de-açúcar através de extração hidrotérmica, de preferência na forma de XOS, e também se avaliou a produção de CNF, um nanomaterial emergente com inúmeras aplicações em diversos setores, como papel, têxteis e eletrônicos. Para selecionar a melhor condição de solubilização de hemicelulose na forma de XOS, as condições do processo hidrotérmicos foram avaliadas com planejamento experimental estatístico 23, com rotação do tipo estrela, a fim de analisar o efeito combinado de temperatura, tempo e concentração de ácido (H2SO4). A melhor condição experimental para produzir XOS com alto rendimento e seletividade foi a 182 °C durante 5,5 minutos e sem adição de ácido, obtendo um hidrolisado com recuperação de 43 % da xilana inicial na forma de XOS e apenas 2 % na forma de xilose. Um segundo tratamento hidrotérmico foi realizado com o objetivo de remover a xilana residual do bagaço tratado, de preferência na forma de XOS. Devido à alta recalcitrância do material, não foi possível encontrar uma condição experimental para obter alta seletividade para XOS no segundo pré-tratamento e, portanto, foi escolhido obter um hidrolisado rico em xilose, um produto que também possui diversas aplicações. As melhores condições experimentais para se obter um hidrolisado rico em xilose foram determinadas a 168 ° C durante 5,5 minutos e 1,01% m/m de H2SO4, obtendo-se uma recuperação de 36 % da xilana presente inicialmente no bagaço na forma de xilose e apenas 3 % na forma de XOS, sendo este um processo altamente seletivo para recuperação da xilana na forma monomérica. A fração sólida oriunda das etapas de extração da xilana foi deslignificada com NaOH e branqueada em duas etapas, com H2O2 em meio alcalino e com NaClO2 em meio ácido, obtendo pasta celulósica com alto teor de celulose (88,9% m/m de celulose). A polpa celulósica foi processada em um refinador de disco mecânico (SupermassColloider) para produzir celulose nanofibrilada (CNF-B). As propriedades morfológicas do CNF-B foram avaliadas e verificou-se que foi semelhante à nanocelulose de polpa Kraft (CNF-K), em relação as suas dimensões, produzida nas mesmas condições. Além disso, a produção do CNF-B consumiu cerca de um terço da energia necessária para obter o CNF-K. O balanço de massa final do processo mostrou uma alta recuperação dos carboidratos originais em produtos de alto valor agregado. A recuperação da xilana foi de cerca de 88% m/m, sendo 43% m/m de XOS e 36% m/m de xilose. O alto conteúdo recuperado dos coprodutos demonstra a alta seletividade das otimizações realizadas. Por fim, o processo obteve alta recuperação e conversão de celulose à CNF-B, com um rendimento de 88% m/m. / A pretreatment has been pursued to maximize the biomass components and achieve a high material´s valorization. Here, we report an integration of pathways, which have been effective to obtain three high value-added products in a biorefinery concept: XOS, xylose and cellulose nanofibrillated (CNF). The maximization of hemicellulose fraction was studied through hydrothermal extraction from sugarcane bagasse, preferably oligosaccharides (XOS) form, and it was also evaluated CNF production, an emerging nanomaterial with numerous applications in diverse sectors such as paper, textiles and electronics. To select the best condition of hemicellulose solubilization in the form of XOS, the hydrothermal process conditions were evaluated with statistical experimental design to analyze the combined effect of temperature, time and acid concentration (H2SO4). The best experimental condition to produce XOS with high yield and selectivity was at 182 ° C for 5.5 minutes and without acid addition, obtaining a hydrolysate with 75% w/w of XOS content, which corresponds to 43% w/w of the original xylan. A second hydrothermal treatment was performed with the aim of remove a residual xylan from treated bagasse, focusing in XOS form. Because of the high susceptibility of the material, it was not possible to find an experimental condition to achieve high selectivity for XOS in the second pretreatment and, therefore, it was chosen to obtain a hydrolyzate rich in xylose, a product with many applications as well. The best experimental conditions to the hydrolyzate system based in xylose was determined at 168 ° C for 5.5 minutes and 1.01% w/w H2SO4, obtaining a xylose\'s yields of 36% w/w (initial xylan). The solid fraction of the second hydrothermal step was deslignificated with NaOH and bleached in two steps, with H2O2 at alkaline medium and with NaClO2 at acid medium, obtaining cellulosic pulp with high cellulose content (88.9% w/w of cellulose). Cellulosic pulp was processed in a mechanical disc refiner (SupermassColloider) to produce fibrillated nanocellulose (CNF-B). The morphological properties of the CNF-B were evaluated, and it was found to be similar to Kraft pulp nanocellulose (CNF-K) produced at same conditions. Besides that, the production of CNF-B consumed about one third of the energy required to obtain CNF-K. CNF-B and CNF-K were also compared in terms of mean diameter and it was obtained 56.72 nm and 36.83 nm, respectively. The final mass balance of the process showed a high recovery of the original carbohydrates in means of high value-added product. The recovery of xylan was around 88%, being 43% w/w of XOS and 36% w/w of xylose. The high content recovered of the co-products demonstrate the high selectivity of the optimizations performed. Thus, this resulted in a high recovery and conversion of cellulose in the CNF-B with a yield of 88% w/w.
98

Protestants Reading Catholicism: Crashaw's Reformed Readership

Davis, Andrew Dean 14 August 2009 (has links)
This thesis seeks to realign Richard Crashaw’s aesthetic orientation with a broadly conceptualized genre of seventeenth-century devotional, or meditative, poetry. This realignment clarifies Crashaw’s worth as a poet within the Renaissance canon and helps to dismantle historicist and New Historicist readings that characterize him as a literary anomaly. The methodology consists of an expanded definition of meditative poetry, based primarily on Louis Martz’s original interpretation, followed by a series of close readings executed to show continuity between Crashaw and his contemporaries, not discordance. The thesis concludes by expanding the genre of seventeenth-century devotional poetry to include Edward Taylor, who despite his Puritanism, also exemplifies many of the same generic attributes as Crashaw.
99

Schnittstellensynthese -Modellierung, Optimierung, Codegenerierung

Kouamo Sime, Michel Carmel, Behler, Christian, Loke, Tobias, Defo, Gilles Bertrand Gnokam 18 July 2006 (has links) (PDF)
Diese Schriftenreihe präsentiert wissenschaftliche Arbeiten zum Entwurf und zur Selbstorganisation von eingebetteten Systemen. In dem ersten Band dieser Schriftenreihe liegt der Fokus auf der Konzeption von „Rekonfigurierbaren Schnittstellen“. Der vorliegende zweite Band stellt eine vollständige Methodik für die Adaptierung von inkompatiblen Schnittstellen in komplexen, verteilten, eingebetteten Systemen vor. Diese Methodik wird als Interface Synthese (IFS) bezeichnet. In den vier Beiträgen werden im Einzelnen die Modellierung, die Analyse und Optimierung sowie die Codegenerierung als methodische Entwurfsschritte untersucht. Der erste Beitrag behandelt die Modellierung von komplexen Kommunikationssystemen als ersten Schritt des Interface Synthesis Design Flows. Es wird ein UML2.0 Profil sowie dessen Transformation in das Synthesewerkzeug vorgestellt. Die zwei folgenden Beiträge befassen sich mit der Analyse und Optimierung der Schnittstellensynthese. Der erste Ansatz basiert auf der Optimierung der Ausführungspipeline, während der zweite Ansatz eine globale Optimierung durch partitionierendes Clustering in Verbindung mit benutzerspezifischen Protokollen anwendet. Der vierte Beitrag greift die Codegenerierung und somit den letzten Schritt des Interface Synthesis Design Flows auf. Es wird ein dedizierter VHDL-Codegenerator vorgestellt, der insbesondere die Rekonfigurierbarkeit der Schnittstelle unterstützt.
100

Lietuvos ir pasaulio šuolininkių į tolį moterų paskutiniųjų bėgimo žingsnių ir atsispyrimo biomechaninių parametrų įtaka šuolio į tolį sportiniam rezultatui / Influence of the last running steps and biomechanical parameters of the take off to the performance of Lithuania‘s and world’s female long jumpers

Bernotaitytė, Aistė 10 September 2013 (has links)
Tyrimo objektas. Žingsnių greitis ir ilgis bei išlėkimo greitis ir kampas. Tyrimo tikslas. Ištirti Lietuvos ir Pasaulio šuolininkių į tolį moterų paskutiniųjų bėgimo žingsnių greičio ir ilgio bei išlėkimo greičio ir kampo įtaką sportiniam rezultatui. Tyrimo uždaviniai: 1. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį paskutiniųjų įsibėgėjimo žingsnių greičio kitimą ir jo įtaką sportiniam rezultatui. 2. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį paskutiniųjų įsibėgėjimo žingsnių ilgio kitimą ir jo įtaką sportiniam rezultatui 3. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį išlėkimo greitį ir jo įtaką sportiniam rezultatui. 4. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį išlėkimo kampą ir jo įtaką sportiniam rezultatui. Tiriamieji. Buvo analizuojamos Pasaulio šuolininkės dalyvavusios 12 Pasaulio lengvosios atletikos čempionate Berlyne (n=8). Lietuvos šuolininkių testavimas atliktas Lietuvos studentų čempionate (2012 m.) Kauno manieže (n=10). Hipotezė. Didelę įtaką šuolio į tolį rezultatui turi bėgimo greitis paskutiniuose metruose prieš atsispyrimą bei išlėkimo greitis ir kampas. Pagrindiniai rezultatai. Pasaulio šuolininkių į tolį greitis paskutiniajame žingsnyje yra 9.33±0,19 m/s, Lietuvos 7.76±0,41 m/s. Pasaulio šuolininkių priešpaskutinis žingsnis yra 2,31±0,17 m, Lietuvos 2,09±0,15 m, paskutinis žingsnis sutrumpėja palyginus su priešpaskutiniuoju 0,24 m, ir 0,06 m atitinkamai. Lietuvos... [toliau žr. visą tekstą] / Research object: Speed and length of the running steps, take off speed and angle. Research goal: To analyze Lithuanian and World female long jumpers –discuss influence of the speed of last running steps as well as takeoff to the performance in the competition. Research tasks: 1. To identify and compare speed ofLithuanian and World long jumpersin the last runningsteps and its influence to the performance in the competition. 2. To identify and compare length of Lithuanian and World long jumpersin the last runningsteps and its influence to the performance in the competition. 3. To identify and compare take off speed of Lithuanian and World long jumpers and its influence to the performance in the competition. 4. To identify and compare take off angle of Lithuanian and World long jumpers and its influence to the performance in thecompetition. Subjects of this research: World’s top female long jumpers who participated at the 12th Athletics Championship in Berlin (n=8). Lithuanian long jumpers who were tested at the Student Athletics Championship in Kaunas in 2012 (n=10). Hypothesis: Significant influence to the result in the long jumps comes from the running speed in the last meters before the take off, also take off speed and angle. Main results: Speed of top World top female long jumpers in the last running step is 9.33±0,19 m/s, meanwhile of Lithuanians 7.76±0,41 m/s. Length of the last step of the World female long jumpers is 2,31±0,17 m, Lithuanians 2,09±0,15 m. The last step... [to full text]

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