Propelentes sólidos são materiais energéticos que produzem gases em alta pressão por meio de uma reação de combustão. Qualquer propelente sólido inclui dois ou mais dos seguintes componentes: oxidante (nitratos e percloratos); combustível (resinas orgânicas ou polímeros); compostos químicos combinando oxidantes e combustíveis (nitrocelulose ou nitroglicerina); aditivos para facilitar processos de produção ou alterar a taxa de queima e inibidores (fita de etilcelulose), para restringir superfícies de combustão. Pequenas percentagens de aditivos são usadas para modificar diversas propriedades mecânicas, químicas e balísticas dos propelentes sólidos: acelerar ou desacelerar a velocidade de combustão (catalisadores e inibidores de combustão, respectivamente); assegurar a estabilidade química para prevenir a deterioração durante a estocagem; controlar as propriedades de processamento durante a produção de propelente (tempo de cura, fluidez para extrusão ou moldagem, etc.); controlar as propriedades de absorção de radiação no propelente em combustão; aumentar a resistência mecânica e diminuir a deformação elástica; e, finalmente, minimizar a sensibilidade térmica. No caso de propelentes sólidos Base Dupla (mistura de duas bases ativas: a nitrocelulose e a nitroglicerina), é possível alterar sua velocidade de queima principalmente pelo emprego de pequenos teores de modificadores balísticos, em geral sais orgânicos de cobre e chumbo. Neste trabalho, estudou-se a aceleração da velocidade de queima de uma formulação conhecida de propelente Base Dupla - BD, alterando o teor total dos modificadores balísticos cromato de cobre e estearato de chumbo (ou plastabil - nome comercial) na receita original, bem como a proporção entre eles. Estas alterações na formulação original devem, idealmente, preservar os parâmetros de desempenho estabelecidos para as propriedades químicas (estabilidade química) e mecânicas (densidade da massa e ensaios de tração), ao mesmo tempo otimizando o desempenho balístico, pelo aumento da velocidade de queima. Os resultados experimentais mostram que para os parâmetros de qualidade elongação e velocidade de queima a interação entre os fatores, Proporção Sal de Chumbo/Sal de Cobre (Fator A) e Teor de Modificadores Balísticos (Fator B) foram significativos, ou seja, quanto maior os fatores pior o resultado com as propriedades. Com os parâmetros de resistência a tração e densidade da massa, o fator A e B respectivamente influenciam negativamente quando aumentado em sua concentração. Para o parâmetro estabilidade química não houve nenhum sinal de melhora ou influencia dos fatores. No caso da velocidade de queima a interação AB é o que mais influencia. Melhorando significativamente a velocidade de queima. / Solid propellants are energetic materials which produce a considerable amount of high-pressure gases by means of a combustion reaction. Any solid propellant formulation includes at least two of the following items: oxidizer (nitrates and perchlorates); fuel (organic resins or polymers); chemical compounds combining oxidizers and fuels (nitrocellulose or nitroglycerine); additives to easy production operations or to modify the burning rate and inhibitors (tape ethyl-cellulose), to restrict the combustion surfaces. Small amounts of additives are employed to modify the mechanical, chemical and ballistic features of the solid propellants: to accelerate or diminish the burning rate (catalysts and inhibitors of burning, respectively); to assure the chemical stability in order to prevent the deterioration during stocking; to control the processing properties during propellant production (curing time, extrusion or casting rheology); to control the radiation absorption in the burning propellant; to enhance the mechanical resistance and to reduce the strain; and, finally, to get the thermal sensitivity to a minimum level. In the case of Double-Base solid propellants (blend of two energetic bases: nitrocellulose and nitroglycerine), it\'s possible to control its burning rate mainly by the use of small amounts of ballistic modifiers, generally copper and lead organic salts. This work has studied the burning rate acceleration of a known Double-Base propellant formulation, by changing the total amount of the ballistic modifiers copper chromate and lead stearate (commercially known as plastabil) in the original formulation, as well as the proportion between them. These changes at the original recipe should preserve, ideally, the performance levels required for the chemical (chemical stability) and mechanical properties (density and stress-strain evaluation), optimizing, at the same time, the ballistic performance, through the burning rate enhancement. Results show that for the parameters of quality and elongation rate of burning the interaction between factors, Proportion of Lead Salt / Salt Copper (Factor A) and content Ballistic Modifiers (Factor B) were significant, ie, the higher the worst factors result with the properties. With the parameters of tensile strength and mass density, the factor A and B respectively negatively influence increased when its concentration. For the chemical stability parameter there was no sign of improvement or influences of factors. In the case of burning rate AB interaction is what most influences. Significantly improving the speed of burning.

L’hybridation, phénomène omniprésent dans de nombreux domaines, a particulièrement influencé l’évolution du cinéma. Alors que les premières générations de cinéastes semblaient avoir tout inventé de ce nouvel art, le cinéma n’a cessé d’emprunter aux dernières technologies et aux dernières formes d’expressions artistiques, à mesure que se mettaient en place des média de plus en plus présents dans la vie quotidienne. L’étude des passerelles qui se multiplient au fil des décennies, permet de cerner les mécanismes qui concourent à l’abolition progressive des frontières entre les média et les disciplines artistiques. Toutefois, la présente recherche ne se borne pas à scruter ces seules œuvres issues des dernières technologies, mais elle se réfère aussi aux pionniers avant-gardistes des années 1920 qui ont posé les bases de l’hybridation. Elle est donc structurée selon deux grands axes : d’une part l’axe historique, l’histoire du cinéma étant profondément marquée par les vicissitudes de notre temps, et d’autre part l’axe de la pluridisciplinarité, incluant les diverses formes d’expressions artistiques et les divers média. Plus spécifiquement, dans le foisonnement de la production cinématographique, la présente étude se propose de faire le point sur la situation du cinéma hybride au tournant du siècle, à partir d’un corpus constitué de douze films produits en France, aux U.S.A. , au Canada et au Japon, entre 1983 et 2004, et auxquels fait pendant Metropolis de Fritz Lang [1927]. Enfin, comme on pourra le constater, cette enquête s’est inspirée des nombreuses et pertinentes études et comptes-rendus qui l’ont précédée. / Hybridisation, which is overwhelmingly present in many fields, has particularly influenced the evolution of cinematographic art. Although the first generations of film-makers seemed to have invented everything in this new art form, the cinema has always borrowed from the most modern technologies and the latest forms of artistic expression, while at the same time the media were taking up a larger and larger place in our everyday lives. The study of the links between them, which multiplied over the decades, allows us to understand the mechanisms contributing to the gradual abolition of the dividing lines between the media and artistic disciplines. However, the present research is not limited to the examination of works resulting from the most recent technological developments, since it also refers back to the avant-garde pioneers of the 1920’s, who set the basis for hybridisation. It is therefore centered around two main axes : on the one hand, the historical axis since cinema history has been profoundly marked by the vicissitudes of our time, and on the other hand the pluridisciplinary axis, including diverse forms of artistic expression and various media. More specifically, amid the wealth of cinematographic productions, this study proposes to take stock of the state of hybrid cinema at the turn of the century, using a corpus composed of 12 films, made in France, the United States, Canada and Japan between 1983 and 2004 and which go hand in hand with Fritz Lang’s Metropolis [1927]. Finally, it can be seen that this study has been inspired by the numerous and pertinent works and reports which have preceded it.

Background: Vancomycin-resistant enterococci (VRE) is a common nosocomial infection. It classifies as Enterococcus faecalis or faecium carrying vanA or vanB gene that alters the bacterial cell wall hence lowering affinity for Vancomycin. Screening for VRE in Swedish hospitals are performed with stool sample pre-grown in selective broth followed by PCR and culture on selective media. Viasures Vancomycin resistance, Real Time PCR Detection Kit indicates that pre-growth in broth is not needed for the analyze. Aim: Comparison between the PCR kit and the subsequent culture on chromogenic agar with or without pre-growth in selective broth. Method: E. faecium with vanA gen (CCUG 36804) and E. faecalis with vanB gen (ATCC 51299) were suspended in different concentrations and added to ESwab transport medium. Thereafter small samples from the ESwab tube were enriched in selective broth. Samples from both selective broth and ESwab medium were analyzed with Viasures PCR kit on BD-MAX system and cultivated on chromogenic agar. Results: With pre-growth in selective broth the genes were found in every sample regardless of pre-concentration in the ESwab medium. Without enrichment the PCR kit always amplified the genes when the concentration was 40 000 cfu/ml for E. faecium (vanA) and ≥ 10 000 cfu/ml for E. faecalis (vanB). Colonies grew on chromogenic agar in every concentration from both ESwab and selective broth. Conclusion: Culture on chromogenic agar is comparable with or without pre-growth in selective broth but Viasure’s PCR kit is not equal for both methods in lower concentrations of the bacteria.

Batrachochytrium dendrobatidis (Bd) is a fungus that causes chytridiomycosis in amphibians. This fungus is an invasive species that has spread all over the world and is causing mass deaths in many areas. Bd has an efficient life cycle which targets suitable hosts and causes disturbances in amphibian osmoregulation and eventually death. It has caused more than 90 presumed extinctions worldwide. However, even though this fungus is commonly found in Sweden, no cases of chytridiomycosis has been found in the wild. This raises the questions i) what factors makes the infection in amphibians more severe and ii) does temperature affect the severity of Bd infection? According to the thermal mismatch hypothesis pathogens should be more efficient at temperatures where the performance gap between the host and pathogen is the widest. We chose the common toad as a study organism since it can be found all over Sweden and is generally considered to be adapted to colder climates. Our aim was to test the thermal mismatch hypothesis and see if the effect of infection differed between different temperatures. Common toad eggs were collected from two ponds in southern Sweden, raised in the laboratory and metamorphosed juvenile toads were reared in three different temperature rooms, either 14℃, 18℃ or 22℃. There they were either infected with Bd or exposed to a sham infection and monitored for 40 days. We show that Bd infection negatively affects growth and survival of common toads in accordance with previous studies. Furthermore, we found that temperature affects the effect of infection and shows patterns of the thermal mismatch hypothesis.

No description available.

No description available.

Les études d'interaction protéine-ligand aident à mieux comprendre la structure et la fonction des protéines. Dans la première partie de la thèse, la cyt bd oxydase a été étudiée. La protéine d'E. coli a été immobilisée avec succès sur des électrodes modifiées par des nanoparticules d'or. Ainsi, un biocapteur électrochimique a été créé, permettant de tester certains inhibiteurs potentiels de cyt bd provenant d’E. coli. Le cyt bd issue de G. thermodenitrificans thermophile a également été étudié. En faisant appel aux spectroscopies IR et Raman ainsi que l’électrochimie, il a été démontré que la protéine est distincte du cyt bd d’E. coli. Une influence mutuelle du pH et de la température sur la catalyse a été aussi démontrée. La deuxième partie de la thèse portait sur la protéine mitochondriale mitoNEET. L'influence du pH et de divers ligands (pioglitazone, resvératrol, ions phosphates) a été examinée. / Protein-ligand interaction studies help to better understand the structure and function of proteins. In the first part of the thesis cyt bd oxidase was studied. The protein from E. coli was successfully immobilised at gold nanoparticles modified electrodes. Thus, an electrochemical biosensor was created allowing testing some potential inhibitors of cyt bd from E. coli. The cyt bd from thermophilic G. thermodenitrificans was also studied. By means of IR, Raman spectroscopy and electrochemistry the protein was shown to be distinct from cyt bd from E. coli. A mutual influence of pH and temperature was demonstrated on the electrochemical and catalytical properties. The second part of the thesis focused on mitochondrial mitoNEET protein. The influence of the pH and various ligands was studied.

As a first aspect the thesis treats existence results of the perturbed eigenvalue problem of the 1-Laplace operator. This is done with the aid of a quite general critical point theory results with the genus as topological index. Moreover we show that the eigenvalues of the perturbed 1-Laplace operator converge to the eigenvalues of the unperturebed 1-Laplace operator when the perturbation goes to zero. As a second aspect we treat the eigenvalue problems of the vectorial 1-Laplace operator and the symmetrized 1-Laplace operator. And as a third aspect certain related parabolic problems are considered.

Aktuelle technologische Herausforderungen, z.B. in der Werkzeugmaschinenentwicklung, erfordern aufgrund der steigenden Genauigkeitsanforderungen an die thermische Simulation eines zu betrachtenden Systems, dass ebenfalls die Auswirkungen relevanter, translatorischer Relativbewegungen zwischen unterschiedlichen Teilen des Systems berücksichtigt werden. Das Vorgehen, diese Bewegung in den Simulationen durch diskrete Verschiebungen zwischen den Lastschritten einer transienten Analyse umzusetzen, führt bei der Verwendung einer infinit kleinen Zeitschrittweite auf die Abbildung einer kontinuierlichen Bewegung, bringt aber gleichzeitig eine problematische Steigerung des notwendigen Rechenaufwands mit sich. Die Anwendung einer langen Zeitschrittweite bei gleichzeitiger Konservierung der Ergebnisgenauigkeit stellt nun einen Ansatz dar, die Effizienz solcher Analysen über den eingesparten Aufwand der nicht auszuwertenden Lastschritte zu steigern. In dieser Arbeit wurden durch eine gezielte Partitionierung der aus einer Ortsdiskretisierung resultierenden Systemmatrizen zunächst vier qualitativ unterscheidbare Fehlerquellen identifiziert, welche die Verwendung einer groben Zeitdiskretisierung potentiell nach sich ziehen kann. Konkret gehören dazu die Leistungsfähigkeit des zur transienten Auswertung verwendeten Integrationsverfahrens, die diskrete Umsetzung der Bewegung sowie die seltene Aktualisierung der beiden Arten von Kontaktlasten. Für die einzelnen Fehler werden die möglichen Auswirkungen jeweils allgemein quantifiziert. Für zwei, dabei als relevant identifizierte Fehlerquellen werden mit der BD- und der RUMHI-Korrektur zugehörige Verfahren entwickelt, mit denen die Ergebnisgenauigkeit trotz grober Zeitdiskretisierung aufwandsarm bewahrt werden kann. Dass ein strukturvariables, thermisches Problem durch die kombinierte dieser Korrekturverfahren deutlich effizienter berechnet werden kann, wird in der Arbeit abschließend an zwei stellvertretenden Problemen beispielhaft gezeigt.

Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations toward the runaway stars ζ Oph by Chandra and Suzaku and of BD+43°3654 by XMM-Newton to search for the presence of non-thermal X-ray emission. We found no evidence of non-thermal emission spatially coincident with the bow shocks; nonetheless, diffuse emission was detected in the vicinity of ζ Oph. After a careful analysis of its spectral characteristics, we conclude that this emission has a thermal nature with a plasma temperature of T ≈ 2 × 106 K. The cometary shape of this emission seems to be in line with recent predictions of radiation-hydrodynamic models of runaway stars. The case of BD+43°3654 is puzzling, as non-thermal emission has been reported in a previous work for this source.