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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.
21

Utilisation et Modification de la β-cyclodextrine et de système mono-osidique en angiogenèse / Use and Modification of β-cyclodextrin and mono-saccharide system in angiogenesis

Assam Evoung, Jean Norbert 21 December 2012 (has links)
La croissance tumorale et le développement des métastases sont dépendants de l'angiogenèse et reposent sur un « switch angiogénique ». Dès lors, inhiber l'angiogenèse apparaît très naturellement comme une nouvelle stratégie thérapeutique anti-cancéreuse qui consiste tout simplement à affamer une tumeur en la privant de sa vascularisation. L'angiogenèse est un processus physiologique qui fait intervenir de nombreux récepteurs, dont le récepteur du mannose-6-Phosphate ou Insulin Growth Factor II (RM6P/IGF-II). Des travaux antérieurs effectués au laboratoire ont montré que des molécules analogues du M6P sont des effecteurs d'angiogenèse mais qu'au cours de leur administration, ces composés sont facilement éliminés car trop hydrophiles. Afin d'obtenir des analogues du M6P plus lipophiles, nous avons remplacé le méthyle en position anomère par un pentyle. Par ailleurs, pour étudier l'effet « cluster » et la protection par une molécule enveloppante, une nouvelle famille de composés dérivant de la β-Cyclodextrine a été préparée. Des dérivés originaux, présentant des fonctions phosphates et azido, ainsi qu'une couronne de mannose ont été synthétisés. / Tumor growth and development of metastasis are dependent on angiogenesis and based on an « angiogenic switch». Therefore, to inhibit angiogenesis appears quite evidently as a new anticancer strategy which corresponds simply to starve a tumor by depriving its vascularisation. Angiogenesis is a physiological process that involves many receptors, including the RM6P/IGF-2. Previous work conducted in the laboratory has shown that analogues of M6P are effectors of angiogenesis but during administration, these compounds are easily removed due to their hydrophilicity. To increase the lipophilicity of the M6P analogues, we have replaced the methyl group at the anomeric position by a pentyl group. Also to study the “cluster” effect and the protective transport of molecules, a new family of compounds derived from β-cyclodextrin were prepared. Original derivatives, having azido and phosphate functions, and a crown made of mannose were synthesised.
22

Preparação e caracterização de sistema bifásico mono-componente (SBM) a partir da reação de oxipropilação de fibras celulósicas e amido / Preparation and characterization of mono-component two-phase system (SBM) by oxypropylation reaction of cellulose fibres and starch

Menezes, Aparecido Junior de 26 January 2007 (has links)
Modificações químicas foram aplicadas às fibras celulósicas e ao amido com o objetivo de obter produtos com uma camada termoplástica externa, preservando a parte interna desses substratos (não modificada). O produto final deveria se comportar como um material compósito onde a parte interna não modificada é o agente de reforço e a camada termoplástica a matriz. As modificações foram realizadas através da inserção de pequenas cadeias de óxido propileno a cadeia carbônica do polissacarídeo (celulose e amido). As cadeias de poli(oxido propileno) enxertadas proporcionará uma camada termoplástica em torno da porção de polissacarídeo não modificada. A obtenção destes materiais pode dispensar as etapas de mistura e permitir o processamento térmico sem a necessidade de utilização de um segundo componente (matriz), uma vez que a própria capa polimérica desempenharia este papel. A construção da capa polimérica envolvente foi conduzida através da reação da celulose ou amido pré-ativados com o óxido de propileno. A etapa de ativação foi realizada com o tratamento dos substratos com KOH ou DABCO e a reação de enxertia foi realizada em sistema heterogêneo. Os materiais obtidos utilizando esses tratamentos foram caracterizados por diferentes técnicas (FTIR, Raios-X, MEV, TG, DSC, Ângulo de contato e ensaios de Resistência à Tração). Os resultados obtidos demonstraram que é possível de produzir materiais com características termoplásticas reforçadas através da reação em uma única etapa, sem a necessidade de laboriosos procedimentos sintéticos. / Chemical modifications were applied to cellulosic materials and starch with the objective to obtain products with an external thermoplastic layer while preserving the inner part of these substrates. The final products should behave as composite materials where the unmodified inner part is the reinforcement agent and the thermoplastic layer the matrix. The modifications were performed by grafting polypropylene oxide short chains to the polysaccharide backbone (cellulose and starch). The grafted polypropylene oxide chains will render a thermoplastic layer around the unmodified polysaccharide portions. The attainment of these materials can excuse the stages of mixture and allow the thermal processing without the necessity of use the second component (matriz), a time that the proper polymeric layer would play this role. The construction of the involving polymeric layer was conducted by reacting pre-activated cellulose (or starch) and propylene oxide (PO). The activation step was performed with KOH (or DABCO) treatment and the grafting reaction was carried through in heterogeneous system. The materials obtained following these treatments were characterized by different techniques (FTIR, X-Ray, MEV, TG, DSC, Contact Angle and Mechanical Analyses). The results had demonstrated that it is possible to produce materials with strengthened thermoplastic characteristics through the reaction in an only stage, without the necessity of laborious synthetic procedures.
23

Estudo do moonpool como sistema de minimização de movimento em uma plataforma do tipo monocoluna. / Study of moonpool as a motion minimization device in a monocolumn type platform.

Torres, Fernando Gomes da Silva 26 March 2007 (has links)
A maioria dos estudos realizados sobre moonpools existentes em embarcações sempre objetivou a redução das amplitudes de oscilação da água interna a estes, pois sua usual utilização é a passagem de linhas de produção, equipamentos e mergulhadores. Estes estudos mostram que com a mudança da geometria interna do moonpool é possível alterar o comportamento de oscilação da água interna ao mesmo. O presente trabalho tem como objetivo estudar o acoplamento entre o movimento vertical da água interna ao moonpool e a dinâmica em heave do corpo flutuante. Os adimensionais que regem o problema são apontados. Através das observações e conclusões em relação aos estudos numéricos e ensaios experimentais realizados, é proposto um modelo massa-mola-amortecedor representando o acoplamento entre o movimento vertical da água interna ao moonpool e a dinâmica em heave do corpo flutuante. / Most published studies related to moonpool existent in vessels always had as it main objective the reduction of vertical oscillation of the water inside the moonpool, as its usual function is the passage of production lines, equipments and divers. These studies show that, through the change of the moonpool\'s internal geometry, it is possible to modify the behavior of vertical oscillation of the water inside the moonpool. The present work has the objective of studying coupling between the vertical movement of the water inside the moonpool and the heave dynamics of the floating-body. The nondimensional numbers that guide the problem are indicated. Through the observations and conclusions in relation to the numerical studies and experimental analysis made, it is proposed a mass-spring-dumper model representing the coupling between the vertical movement of the water inside the moonpool and the heave dynamics of the floating-body.
24

Estudo de um motor ciclo diesel monocilíndrico bi-combustível

Rosa, Josimar Souza 21 March 2014 (has links)
Submitted by Maicon Juliano Schmidt (maicons) on 2015-05-07T16:35:35Z No. of bitstreams: 1 Josimar Souza Rosa.pdf: 2316699 bytes, checksum: 10b8be8bf5285234719e629c53ebeb82 (MD5) / Made available in DSpace on 2015-05-07T16:35:35Z (GMT). No. of bitstreams: 1 Josimar Souza Rosa.pdf: 2316699 bytes, checksum: 10b8be8bf5285234719e629c53ebeb82 (MD5) Previous issue date: 2014-03-21 / Nenhuma / Este trabalho buscou analisar o funcionamento de um motor de combustão interna (ciclo Diesel) operando com misturas parciais de óleo diesel com gás natural veicular, e óleo de soja com gás natural veicular. Os ensaios foram realizados em um motor Agrale modelo M90, monocilíndrico, acoplado a um alternador, tendo como carga um banco de resistências. A análise realizada contemplou o desempenho em termos de consumo de combustível, potência e emissões gasosas de óxidos de nitrogênio, dióxidos de enxofre, monóxido de carbono, entre outros gases, bem como a análise da opacidade da fumaça. Os resultados mostraram que é viável a utilização de gás natural em motores ciclo Diesel sem remoção do sistema de injeção de diesel original, representando uma considerável redução nas emissões específicas dos óxidos de nitrogênio, sem perda de potência, porém resultando em combustão incompleta em altos percentuais de substituição de combustível líquido por gasoso. De maneira geral o melhor resultado em relação à eficiência foi possível com percentual de substituição de 43,7% de diesel por gás natural, no qual o conjunto motor gerador apresentou rendimento aproximado de 33,17%. A opacidade da fumaça emitida pelo motor foi reduzida significativamente quando funcionou em modo bi-combustível tanto com diesel e gás natural como óleo de soja e gás natural. / This study aims to analyze the operation of an internal combustion engine (diesel cycle) with partial mixtures of diesel oil and natural gas, and oil vegetable soybean and natural gas. The tests were carry in an engine Agrale model M90, monocilynder, coupled to alternator, and which charged a bank of resistors load. The analyses include performance fuel consumption, power and gas emissions of nitrogen oxides, sulfur dioxides, carbon monoxide, and other gases, as well the analysis of the smoke opacity. Results showed that it is feasible to use natural gas in diesel cycle engines without removing the original diesel injection system, generating a considerable reduction in specific emissions of nitrogen oxides, without loss of Power, but resulting in incomplete combustion at high percentages replacement of liquid fuel for natural gas. Generally, the Best result for efficiency was possible with replacement percentage of 43,7% of diesel per natural gas, when the generation setting showed efficiency equal at 33,17%. The smoke opacity was reduced significantly when operated in dual fuel both diesel and natural gas as soybean oil and natural gas.
25

The phonology and morphology of Mono /

Olson, Kenneth Scott. January 2001 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Linguistics, March, 2001. / Includes bibliographical references. Also available on the Internet.
26

Estudo do moonpool como sistema de minimização de movimento em uma plataforma do tipo monocoluna. / Study of moonpool as a motion minimization device in a monocolumn type platform.

Fernando Gomes da Silva Torres 26 March 2007 (has links)
A maioria dos estudos realizados sobre moonpools existentes em embarcações sempre objetivou a redução das amplitudes de oscilação da água interna a estes, pois sua usual utilização é a passagem de linhas de produção, equipamentos e mergulhadores. Estes estudos mostram que com a mudança da geometria interna do moonpool é possível alterar o comportamento de oscilação da água interna ao mesmo. O presente trabalho tem como objetivo estudar o acoplamento entre o movimento vertical da água interna ao moonpool e a dinâmica em heave do corpo flutuante. Os adimensionais que regem o problema são apontados. Através das observações e conclusões em relação aos estudos numéricos e ensaios experimentais realizados, é proposto um modelo massa-mola-amortecedor representando o acoplamento entre o movimento vertical da água interna ao moonpool e a dinâmica em heave do corpo flutuante. / Most published studies related to moonpool existent in vessels always had as it main objective the reduction of vertical oscillation of the water inside the moonpool, as its usual function is the passage of production lines, equipments and divers. These studies show that, through the change of the moonpool\'s internal geometry, it is possible to modify the behavior of vertical oscillation of the water inside the moonpool. The present work has the objective of studying coupling between the vertical movement of the water inside the moonpool and the heave dynamics of the floating-body. The nondimensional numbers that guide the problem are indicated. Through the observations and conclusions in relation to the numerical studies and experimental analysis made, it is proposed a mass-spring-dumper model representing the coupling between the vertical movement of the water inside the moonpool and the heave dynamics of the floating-body.
27

Preparação e caracterização de sistema bifásico mono-componente (SBM) a partir da reação de oxipropilação de fibras celulósicas e amido / Preparation and characterization of mono-component two-phase system (SBM) by oxypropylation reaction of cellulose fibres and starch

Aparecido Junior de Menezes 26 January 2007 (has links)
Modificações químicas foram aplicadas às fibras celulósicas e ao amido com o objetivo de obter produtos com uma camada termoplástica externa, preservando a parte interna desses substratos (não modificada). O produto final deveria se comportar como um material compósito onde a parte interna não modificada é o agente de reforço e a camada termoplástica a matriz. As modificações foram realizadas através da inserção de pequenas cadeias de óxido propileno a cadeia carbônica do polissacarídeo (celulose e amido). As cadeias de poli(oxido propileno) enxertadas proporcionará uma camada termoplástica em torno da porção de polissacarídeo não modificada. A obtenção destes materiais pode dispensar as etapas de mistura e permitir o processamento térmico sem a necessidade de utilização de um segundo componente (matriz), uma vez que a própria capa polimérica desempenharia este papel. A construção da capa polimérica envolvente foi conduzida através da reação da celulose ou amido pré-ativados com o óxido de propileno. A etapa de ativação foi realizada com o tratamento dos substratos com KOH ou DABCO e a reação de enxertia foi realizada em sistema heterogêneo. Os materiais obtidos utilizando esses tratamentos foram caracterizados por diferentes técnicas (FTIR, Raios-X, MEV, TG, DSC, Ângulo de contato e ensaios de Resistência à Tração). Os resultados obtidos demonstraram que é possível de produzir materiais com características termoplásticas reforçadas através da reação em uma única etapa, sem a necessidade de laboriosos procedimentos sintéticos. / Chemical modifications were applied to cellulosic materials and starch with the objective to obtain products with an external thermoplastic layer while preserving the inner part of these substrates. The final products should behave as composite materials where the unmodified inner part is the reinforcement agent and the thermoplastic layer the matrix. The modifications were performed by grafting polypropylene oxide short chains to the polysaccharide backbone (cellulose and starch). The grafted polypropylene oxide chains will render a thermoplastic layer around the unmodified polysaccharide portions. The attainment of these materials can excuse the stages of mixture and allow the thermal processing without the necessity of use the second component (matriz), a time that the proper polymeric layer would play this role. The construction of the involving polymeric layer was conducted by reacting pre-activated cellulose (or starch) and propylene oxide (PO). The activation step was performed with KOH (or DABCO) treatment and the grafting reaction was carried through in heterogeneous system. The materials obtained following these treatments were characterized by different techniques (FTIR, X-Ray, MEV, TG, DSC, Contact Angle and Mechanical Analyses). The results had demonstrated that it is possible to produce materials with strengthened thermoplastic characteristics through the reaction in an only stage, without the necessity of laborious synthetic procedures.
28

Design de précurseurs organométalliques et synthèse contrôlée de nano-objets de germaniure de fer / Design of organometallic precursors to synthezise iron germanide nanoparticles

Sodreau, Alexandre 19 November 2018 (has links)
La synthèse contrôlée de nano-alliages de germaniure de fer a connu un regain d'intérêt grâce à la récente découverte de nouvelles applications dans le domaine du stockage d'informations. Toutefois, la chimie du couple fer-germanium est une chimie complexe qui reste peu étudiée. Ces travaux de thèse associent chimie moléculaire et chimie des nano-objets pour explorer les potentialités de précurseurs mono-sources pour la synthèse en solution et en conditions douces de NPs de germaniure de fer. Dans un premier temps, nous nous sommes intéressés à la formation de nouveaux complexes présentant une architecture de type amidinatogermylène offrant un équilibre entre la stabilisation des complexes et leurs températures de décomposition, par exemple les complexes mono-germylène fer {[iPrNC(tBu)NiPr]GeCl}Fe(CO)4 et {[iPrNC(tBu)NiPr]GeHMDS}Fe(CO)4 ou le complexe bis-germylène fer {[iPrNC(tBu)NiPr]GeCl}2Fe(CO)3. Dans un second temps, nous montrons que cette méthode constitue une voie de choix permettant la formation de nano-alliages de germaniure de fer et que l'architecture des précurseurs mono-sources permet d'obtenir un contrôle sur les nanoparticules finales. En particulier, la décomposition à 200°C du complexe {[iPrNC(tBu)NiPr]GeHMDS}Fe(CO)4 conduit à la formation de nanoparticules sphériques de phase Fe3,2Ge2, de 6,5 ± 0,8 nm, présentant un comportement ferromagnétique. / Controlled synthesis of nano-alloys of iron germanide has gained a renewed interest thanks to the recent discovery of new applications in the field of information storage. However, the chemistry of the iron-germanium pair is a complex chemistry that remains little studied. The work presented in this thesis combines molecular chemistry and nano-object chemistry to explore the potential of single-source precursors for solution synthesis, in soft conditions, of iron germanium NPs. First, we focused on the formation of new complexes with an amidinatogermylene-type architecture offering a balance between the stabilization of complexes and their decomposition temperatures, for example mono-germylene iron complexes {[iPrNC(tBu)NiPr]GeCl}Fe(CO)4 and {[iPrNC(tBu)NiPr]GeHMDS}Fe(CO)4 or the bis-germylene iron complex {[iPrNC(tBu)NiPr]GeCl}2Fe(CO)3. In a second step, we show that this method represents a path of choice to reach the formation of nano-alloys of iron germanide and that the architecture of the mono-source precursors allows to control the final nanoparticles. In particular, the decomposition at 200°C. of the {[iPrNC(tBu)NiPr]GeHMDS}Fe(CO)4 complex leads to the formation of Fe3,2Ge2 spherical nanoparticles, with a mean diameter of 6.5 ± 0.8 nm, exhibiting a ferromagnetic behavior.
29

Flexible and Scalable Algorithm/Architecture Platform for MP-SoC Design of High Definition Video Compression Algorithms

Bonaciu, M. 04 July 2006 (has links) (PDF)
Ces dernières années, la complexité des puces a augmenté exponentiellement. La possibilité d'intégrer plusieurs processeurs sur la même puce représente un gain important, et amène au concept du système multiprocesseur hétérogène sur puce (MP-SoC). Cet aspect a permis d'amplifier de manière significative la puissance de calcule fourni par ce type de puce. Il est même devenu possible d'intégrer des applications complexes sur une seule puce, applications qui nécessitent beaucoup de calculs, de communications et de mémoires. Dans cette catégorie, on peut trouver les applications de traitement vidéo MPEG4. Pour obtenir de bonnes implémentations en termes de performances, (1) un algorithme de l'encodeur MPEG4 flexible a été réalisé, pouvant être facilement adapté pour différents types de paramètres d'algorithme, mais également différents niveaux de parallélisme/pipeline. Puis, (2) une modélisation flexible a été utilisée, pour représenter différents models d'algorithme et d'architecture contenant 2 SMP. Utilisant ces models, (3) une exploration d'algorithme et d'architecture à un haut niveau d'abstraction a été proposé, en vue de trouver les configurations correctes d'algorithme et d'architectures, nécessaires pour différents applications. A partir de ces configurations, (4) un flot automatique d'implémentation d'architectures RTL a été utilisé. En utilisant ces aspects, l'encodeur MPEG4 a été implémenté avec succès dans plusieurs architectures spécifiques MP-SoC au niveau RTL. La même approche a été utilisée pour l'implémentation de l'encodeur MPEG4 sur une architecture quadri-processeurs existante, pour différentes résolutions, frame-rate, bitrates, etc.
30

Determining cross-reactivity between human and mouse tissue using mono-specific antibodies

Monazzami, Avin January 2007 (has links)
<p>ABSTRACT</p><p>The Swedish Human Proteome Resource (HPR) is a project about mapping of human genes and proteins. It aims to describe the function and distribution of all human genes and corresponding proteins, using in-house produced antibodies and tissue microarrays (TMA) for enzyme based immunohistochemistry. The mono-specific antibodies are used for immunostaining of human tissue. Specific predicted antigens named Protein Epitope Signature Tag (PrEST) are needed to produce mono-specific antibodies. PrEST are produced using recombinant technology from predicted genes and used as immunogens to produce (mono-specific) antibodies in rabbits. In this study, 84 mono-specific antibodies with known specificity to human proteins were used for immunohistochemical analysis of mouse tissues to determine the cross reactivity between mouse and human.</p><p>For 6 of the 84 antibodies the results differed between mouse and human tissue. A comparison between the PrEST used with the mouse proteome using database search programs showed homologies that were less than 100% in these six cases.</p><p>Thus, future studies on cross reactivity will focus on how to increase the accuracy in its prediction at the in silico stage of the experiment.</p>

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