Nesta tese, dois projetos distintos que usaram a técnica do Espalhamento de Luz foram desenvolvidos. Estudou-se a influência de soluções concentradas de uréia sobre agregados supramoleculares de anfifilicos (ASA\'s), através de condutimetria, supressão de fluorescência e espalhamento de luz. A uréia causou aumento da concentração micelar crítica (CMC) em todos os sistemas micelares estudados. A uréia diminuiu a seletividade da ligação iônica entre cloreto e brometo em micelas de haleto de cetil-trimetil-amônio, estudada através de supressão de fluorescência. Este aditivo causou também aumento na segunda CMC de brometo de tetradeciltrimetil- amônio (TTAB) e diminuição do peso molecular das micelas em bastão formadas. Concluiu-se, desta primeira parte, que a uréia tende a interferir nas transições de fase apresentadas em sistemas micelares, provavelmente através da combinação dos mecanismos direto e indireto. A uréia apresenta potencial para uso como aditivo para modulação das propriedades estruturais de sistemas micelares. Na segunda parte da tese desenvolveu-se um sistema, baseado em espalhamento de luz, capaz de monitorar o peso molecular de polímeros durante a polimerização. O sistema foi eficiente no monitoramento da polimerização da N-vinil-pirrolidinona, mostrando que o peso molecular do polímero formado é constante durante a maior parte da reação. As teorias atuais de cinética de polimerização não foram capazes de explicar esse comportamento. / Light scattering techniques (static and dynamic) were used to detenninate the effect of urea on supramolecular aggregates and to monitor on-line molar mass ofpolymerization reactions. For the first set of investigation it was already established that urea increases the CMC and the dissociation degree (α) of ionic micelles (CTABr, TTABr, and SDS). From fluorescence suppression studies it was found that urea diminishes the ionic binding in zwitterionic and cationic micelles as well as in cationic vesicles. Bromide and chloride ionic selectivity in cationic micelles was found to nearly disappear in the presence of urea. Light scattering (static) detenninations showed that the weight averaged molecular weight (Mw) ofboth SDS and CTABr are invariant by the presence of the denaturant. A slight increase in the excluded volume tenn (A2) was detected for CTABr in the presence of 3M urea. In parallel both A2 and the radius of gyration (γ) of two polyelectrolytes (PAA and Hyaluronic acid) were not affected by the presence of urea. Sphere-to-rod concentration transitions (2nd CMC) of TIABr micelles increased in the presence of urea and the MW of rod particles were observed to decrease. For the insoluble mixture of CTABr/Polystyrenesulfonate solubilization was achieved in the presence of 3M urea. These set of results were explained as a result of the dual effect of urea, that is, the indirect effect by changing the properties of the solvent and the direct effect by solvating the hydrophilic domain of the aggregates and contributing with a stronger dipole moment. The second set of experiments was directed towards the real-time, on-line monitoring of Mw of polymerization reactions. This new approach could be succeeded by the coupling a light scattering detector, an UV photometer and a differential refractometer on line with a HPLC system. Mw growth formed in the polymerization of N-vynil-pirrolidone was accomplished with a small inherent error. Within the studied conditions Mw reached a plateau at early polymerization stages, after that only an increase in the number of polymer kinetic chains was observed. Current kinetic models were unable to predict the observed Mw growth pattern. This system is of great importance in basic and technological applications by virtue of its on-line capability.

O Papilomavírus Humano (HPV) é uma prevalente infecção do mundo atual, sendo o comportamento sexual um fator determinante para a o acometimento da infecção. O objetivo deste trabalho foi estudar o HPV em diferentes sítios de infecção, buscando um maior entendimento do seu mecanismo de disseminação. Foram analisadas amostras das mucosas cervical, oral e do sangue de 50 pacientes do sexo feminino. Foram identificados o HPV-16, HPV-18, HPV-31 e HPV-33. Nenhuma paciente foi negativa para os quatro tipos nos três sítios. O HPV-16 foi o mais detectado e o mais prevalente nos três sítios, simultaneamente, 32 pacientes apresentaram esse perfil. Todos os tipos virais presentes no sangue, também estavam presentes na mucosa cervical, na mucosa oral ou em ambas. Foram identificados seis achados citológicos, sugestivos da infecção pelo HPV. Foi realizada a detecção dos transcritos virais de E6, E6/E7 e L1 nos três sítios. Os resultados do nosso trabalho demonstram a alta prevalência do HPV, a atividade viral nos três sítios analisados e a provável disseminação do vírus. / Human papillomavirus (HPV) is one of the most prevalent infections of the current world, with sexual behavior being one determining fator of infection. The objective of this study was to study HPV in different sites of infection, seeking a better understanding of its mechanism and spreading. Cervical, oral and blood mucosa samples from 50 female patients were analyzed. HPV-16, HPV-18, HPV-31 and HPV-33 were identified. No patient was negative in the four types at all three sites. HPV-16 was the most detected and the most prevalent in the three sites, simultaneously, 32 patients presented this profile. All viral types present in the blood were also present in the cervical mucosa, oral mucosa, or both. Six cytological findings were identified, suggestive of infection by HPV. Detection of viral transcripts of E6, E6 / E7 and L1 was performed at the three sites. The results of our study demonstrate the high prevalence of HPV, viral activity in the three sites analyzed and the probable virus spreading.

Currently, the high speed and low price are required for construction works in the modern architecture. Therefore, it is necessary to deal with verifying the quality of the constructions. Dissertation thesis is focused on evaluating the quality of the execution of sprayed concrete without accelerating additives applied by spraying by a dry way manually-sprayed. The quality of shotcrete was judged on the basis of standardized both non-destructive and destructive methods using sprayed samples. The quality of shotcrete was assessed in terms of strength of sprayed concrete in pressure, density and homogeneity judged on the basis of the velocity of sound samples. The destructive method was carried out on the core samples which were pressured on the hydraulic press, as the non-destructive method was used ultrasonic passageway method based on the propagation velocity of the ultrasonic pulse. On the basis of our results and their mutual correlations, it has been proposed the modifications of the general equal used for predicting the strength of the sprayed concrete tested by our strength class, which leads to a potential reduction in the number of cores on the real structure, and therefore reduce the price of implementation of qualitative tests and increase effectiveness of carrying out tests on the construction place.

No description available.

This thesis deals with a method of spectrum-spreading of the data signals transmitted in the radio channel. There exist three different ways of spreading application, they uses pseudorandom sequences and also orthogonal sequences. In these systems we can find various kinds of modulations, one of them (Quadrature Phase Shift Keying) is shown at the end of the thesis. Spectrum spreading orthogonal multiplex OFDM is based on this method. The thesis wants to present the principle of the spectrum spreading method and the description of systems, transmitters and receivers that are using this method.

L’objectif est la construction numérique d’un modèle 3D régional de la plaine de Sidi Bouzid permettant la quantification du transfert hydrique et du rôle des crues sur le processus de recharge. Des simulations numériques de l’écoulement ont été réalisées à l’aide de Feflow et validées par des données mesurées in situ. Une conceptualisation des paramètres d’entrée a été réalisée afin de contourner l’absence de données mesurées. L'hétérogénéité de la zone non saturée a un impact significatif sur la variation du flux vertical et la propagation du front d’humidité. Les résultats obtenus en 1D ont été spatialisés à l’échelle de la plaine avec l’objectif de quantifier l’ensemble des flux d’écoulements. L’originalité réside, d’une part, dans la détermination des conditions aux limites appliquées à la surface du sol à partir des hydrogrammes des crues enregistrés et, d’autre part, au modèle conceptuel limitant l’évaporation. Le modèle hydrodynamique a mis en évidence que le bilan hydrique est fortement excédentaire. Les simulations de l’écoulement ont montré que l’approche des épandages de crues au niveau des périmètres surestime la recharge artificielle de la nappe. / The aim of this study is to set up a 3D regional model to quantify water flux in unsaturated-saturated zones and the role of floods on the recharge process. Therefore, numerical flow simulations were conducted using the finite element Feflow that will be validated by measured data. A conceptualization of input parameters was carried out to overcome the absence of measured data. The heterogeneity of the vadose zone have a significant impact on the variation of the vertical flow, the residence time and the propagation of wetting front in the unsaturated zone. The results obtained in 1D were then used to quantify groundwater recharge of the entire area of the study site. The original approach is to derive the time-dependent hydraulic boundary condition of water level at the soil surface of the spreading perimeters by measured flood hydrographs and to develop a limited conceptual model of water uptake by evaporation. The hydrodynamic model showed that the water balance is very important. Flow simulations have shown that the perimeter flooding approach overestimates the artificial recharge of the aquifer.

Le transport routier est responsable d’une partie des émissions de polluants sur la planète. Conscient de ce problème, des lois sur les émissions des véhicules sont régulièrement votées afin de réduire l’impact environnemental du transport automobile. Ces lois de plus en plus restrictives ont poussé les fabricants automobiles à réduire la taille des moteurs essence et à utiliser des procédés d’injection directe afin d’augmenter le ratio puissance/volume des moteurs et réduire la consommation. Cependant avec l’utilisation de l’injection directe, de nouveaux problèmes apparaissent, notamment la production de particules fines, elles-mêmes réglementées. Cette thèse s’inscrit dans ce cadre. En effet, les films liquides engendrés par l’injection de carburant sont identifiés comme principaux responsables de la production de particules. Dans ce contexte, les films liquides sont étudiés expérimentalement à l’aide d’un injecteur haute pression disposant de 3 trous. Les aspects dynamiques de création et d’étalement du film liquides sont étudiés et modélisés. S’en suit une étude thermique de l’interaction entre le spray et la paroi. Afin de caractériser les pertes de chaleur observées lors de l’impact, ces pertes thermiques étant responsables d’un délai dans la vaporisation du carburant et donc d’inhomogénéités du mélange au moment de la combustion, une modélisation de ces pertes et du transfert thermique associé est aussi proposée. Enfin une étude des taux d’évaporation de plusieurs alcanes purs puis de mélanges est proposée. Ces mesures ont servi à la calibration d’un modèle numérique d’évaporation de films fins de carburants sur des parois chaudes. Autour de ces différentes études, une campagne d’essais moteurs a été effectuée. L’objectif est de confirmer que les études expérimentales faites en laboratoires sont bien transposables (moyennant la prise de certaines précautions) aux moteurs automobiles. Les conclusions des différentes études sont finalementproposées / The road transport is responsible of a considerable amount of pollutants emissions at the worldwide scale. To tackle this issue, many laws are trying to give a framework to reduce the emissions at the global scale. The law are always more restrictive, and they oriented the car manufacturers to the reduction of their gasoline engine size. This phenomenon, called downsizing, lead to the use of direct injection in order to improve the power/volume ratio of the engine. However, with direct injection the problem of particle emissions arose. Indeed, the liquid film generated during the injection process are responsible of inhomogeneities in the combustion chamber which lead to particles formation. In this context, the study of the fuel films in the combustion chamber is a major concern. To perform this study several experimental apparatus are designed in this thesis. A high-pressure 3-hole solenoid injector is used in order to generate liquid films. The generation and the spreading of the liquid films is observed and modelled. Then the thermal aspects of the spray impingement is studied, to characterise the local heat transfer. These thermal loss are delaying the evaporation of the liquid film, which will lead to inhomogeneities in the combustion chamber and particle generation. A modelling of the heat transfer is also proposed, finally the evaporation rate of alkanes films is proposed. Mono and multicomponents films are studied, these measures were used to calibrate a numerical model for the evaporation of thin liquid films on hot walls. Together with the previous experimental investigationsand models a test campaign on a real engine has been held. The objective is to confirm that, the results produced out of the engine are transposable to the engine (with careful attention). Conclusions on the different aspects are then presented

Molluscs as well as all other invertebrates rely on innate immune response only. Their internal defense system is capable of destroying most pathogens. However, there are some exceptions, e.g. some snails serve as intermediate hosts for some trematodes. Trematodes are able to develop inside these snails due to intervention in the snail internal defense system. The submitted thesis describes hemocyte activities of two lymnaeid snails, Lymnaea stagnalis a Radix lagotis, and the influence of Trichobilharzia regenti infection on R. lagotis hemocytes. Hemocytes of both species exposed to various chemicals produced different amounts of H2O2 and NO. The response varied between both lymnaeid species. The amount of circulating hemocytes was elevated in R. lagotis snails due to T. regenti infection. However, the infenction attenuated hemocyte activities monitored by us. Hemocyte basal NO production was decreased as well as phagocytosis of bacteria, cell adherence and pseudopodia formation. Toxicity of L. stagnalis plasma against T. regenti miracidia was also described. Mechanisms used by trematodes to interact with the snail internal defense system will help us to understand why one species is suitable for the develepment of the trematode whereas another closely related species kills it. Powered by TCPDF (www.tcpdf.org)

Cette thèse présente une étude des propagations des corrélations dans les systèmes avec interaction de longue portée. La dynamique des observables locales ne peut pas être décrite avec les méthodes utilisées pour la physique statistique à l’équilibre et les approches complètement nouvelles doivent être développées. Différentes bornes sur l’évolution temporelle des corrélations ont été dérivées, mais la dynamique réelle trouvée dans des données expérimentales et numériques est beaucoup plus compliquée avec différents régimes de propagation. Une approche plus spécifique est donc nécessaire pour comprendre ces phénomènes. Nous présentons une méthode analytique pour décrire l’évolution temporelle d’observables génériques dans des systèmes décrits par des hamiltoniens quadratiques avec interactions de courte et longue portée. Grâce ces expressions, la propagation des observables peut être interprétée comme la propagation des excitations du système. Nous appliquons cette méthode générique à un modèle de spins et on obtient trois régimes différents. Ils peuvent être directement expliqués qualitativement et quantitativement par les divergences du spectre des excitations. Le résultat le plus important est le fait que la propagation, là où elle n’est pas instantanée, est au plus balistique, voir plus lente, alors les bornes permettent une propagation significativement plus rapide. On applique les mêmes expressions analytiques à un système de bosons sur un réseau avec interaction de longue et courte portée. Nous étudions les corrélations à deux corps qui ont un comportement toujours balistique et les corrélations à un corps qui ont un comportement plus riche. Cet effet peut être expliqué en calculant la contribution aux deux observables des différentes excitations qui déterminent les parties du spectre contribuant à l’observable. Ces résultats démontrent que la propagation des observables n’est pas déterminée uniquement par le spectre des excitations mais également par des quantités qui dépendent de l’observable et qui peuvent changer complètement le régime de propagation. / In this thesis we present our results on the propagation of correlations in long-range interacting quantum systems. The dynamics of local observables in these systems cannot be described with the standard methods used in equilibrium statistical physics and completely new methods have to be developed. Several bounds on the time evolution of correlations have been derived for these systems. However the propagation found in experimental and numerical results is completely different and several regimes are present depending on the long-range character of the interactions. Here we present analytical expressions to describe the time evolution of generic observables in systems where the Hamiltonian takes a quadratic form with long- and short-range interactions. These expressions describe the spreading of local observables as the spreading of the fundamental excitations of the system. We apply these expressions to a spin model finding three different propagation regimes. They can be described qualitatively et quantitatively by the divergences in the energy spectrum. The most important result is that the propagation is at most ballistic, but it can be also significantly slower, where the general bounds predict a propagation faster than ballistic. This points out that the bounds are not able to describe properly the propagation, but a more specific approach is needed. We then move to a system of lattice bosons interacting via long-range interactions. In this case we study two different observables finding completely different results for the same interactions: the spreading of two-body correlations is always ballistic while the one of the one-body correlations ranges from faster-than-ballistic to ballistic. Using our general analytic expressions we find that different parts of the spectrum contribute differently to different observables determining the previous differences. This points out that an observable-dependent notion of locality, missing in the general bounds, have to be developed to correctly describe the time evolution.

No description available.