Ce travail de thèse porte sur la compréhension et le contrôle du procédé de croissance de films de diamant nanocristallin (DNC) par dépôt chimique en phase vapeur assisté par plasma micro-onde distribué. Deux axes de travail ont été suivis pour atteindre ces objectifs : une étude « matériau » visant à étudier les mécanismes de germination et de croissance et les caractéristiques des films de DNC élaborés ; une étude « plasma » s’intéressant au diagnostic des décharges basse pression H₂ /CH₄/CO₂ utilisées pour la croissance.Concernant le premier volet, des techniques de caractérisation ex situ, telles que la microscopie électronique à balayage, à transmission haute résolution et à force atomique, la spectroscopie Raman, la diffraction des rayons X, la réflectométrie UV-visible, et in situ, telles que l’interférométrie de réflectance laser, ont été mises en oeuvre pour étudier la densité de germination, la morphologie, la topographie, la microstructure, la pureté et la vitesse de croissance des films de DNC. L’influence de certains paramètres du procédé, tels que la pression dans l’enceinte, la position du substrat, la composition gazeuse, la température de surface, la puissance micro-onde et le prétraitement ex situ du substrat, a été étudié pour le silicium. La synthèse de DNC jusqu’à une température aussi basse que 130 °C a ainsi pu être maîtrisée. La faisabilité de la croissance à cette température sur un matériau polymère comme le polytétrafluoroéthylène (PTFE) a été démontrée. La croissance de films de DNC sur d’autres types de substrats tels que le nitrure de silicium et l'acier inoxydable a également été examinée. Concernant la deuxième partie de ce travail, le diagnostic du plasma de dépôt a été effectué par spectroscopie optique d’émission et spectroscopie d'absorption infrarouge en utilisant comme sources de rayonnement des diodes lasers accordables en longueurs d’ondes et des lasers à cascade quantique à cavité externe. L’influence des conditions expérimentales, en particulier de la puissance micro-onde et de la pression dans l’enceinte, sur la concentration du radical méthyl CH₃, précurseur de croissance du diamant, et de cinq molécules stables (CH₄, CO₂, CO, C₂H₂, C₂H₆), ainsi que sur le degré de dissociation de H₂ et les températures cinétiques, vibrationnelles et rotationnelles des espèces, a été étudiée. Le degré de dissociation élevé des précurseurs gazeux, pour une température de gaz relativement faible de quelques centaines de kelvins, indiquent que la chimie du plasma est principalement gouvernée par des processus électroniques. Le système à plasma micro-onde distribué utilisé permet cependant de produire certaines espèces de croissance et de gravure en quantité comparable aux procédés de croissance de DNC conventionnels tout en permettant le processus de synthèse à basse température. / This PhD thesis focuses on the understanding and the control of the nanocrystalline diamond (NCD) film growth process by distributed antenna array microwave plasma-assisted chemical vapor deposition. Two approaches were followed to reach these objectives: a « material » study aiming at studying the nucleation and growth mechanisms and the characteristics of the synthesized NCD films; a « plasma » study focusing on the diagnostics of H₂/CH₄/CO₂ low-pressure discharges used for NCD growth.Concerning the first part of this work, ex situ characterization techniques, such as scanning and high resolution transmission electron microscopy, atomic force microscopy, Raman spectroscopy, X-ray diffraction, UV-visible reflectometry, and in situ, such as laser reflectance interferometry, were used to study the nucleation density, morphology, topography, microstructure, purity, and growth rate of NCD films. The influence of some process parameters, such as chamber pressure, substrate position, gas composition, surface temperature, microwave power and ex situ substrate pretreatment, has been studied for silicon. The synthesis of NCD down to a substrate temperature as low as 130 °C has been thus investigated. The feasibility of NCD growth at this temperature on a polymeric material such as polytetrafluoroethylene (PTFE) has been demonstrated. The growth of NCD films on other kinds of substrates such as silicon nitride and stainless steel was also examined.Concerning the second part of this work, the diagnostics of the deposition plasma was carried out by optical emission spectroscopy and infrared absorption spectroscopy using wavelength-tunable laser diodes and external cavity quantum cascade lasers as radiation sources. The influence of the experimental conditions, in particular of the microwave power and the pressure in the chamber, on the concentration of the methyl radical CH₃, the diamond growth precursor, and of five stable molecules (CH₄, CO₂, CO, C₂H₂, C₂H₆), as well as on the degree of dissociation of H₂ and the kinetic, vibrational and rotational temperatures of the species, was studied. The high degree of dissociation of gas precursors, for a relatively low gas temperature of a few hundred degrees, indicates that the plasma chemistry is mainly governed by electronic processes. The considered distributed microwave plasma system nevertheless allows to produce some growth and etching species in amount comparable to conventional NCD growth processes, while permitting low temperature synthesis process.

A reliable estimation of in situ stress orientation and magnitude is necessary for determining wellbore stability in the oil and gas industry, or assessing excavation stability for mining and civil engineering projects. Methods of stress estimation in deep borehole investigations are generally limited to the use of hydraulic methods or borehole imaging techniques, which identify borehole breakouts and/or borehole deformation. However, the collection of data in a thrust regime, or in horizontally laminated ground, can be difficult and lead to unreliable results. Moreover, the back analysis of stress magnitude from both hydraulic methods and borehole imaging methods are sensitive to estimates of strength and elastic properties around the borehole. This research has shown that the magnitude of the axial stress relative to the stresses normal to the borehole axis contributes to the magnitude and distribution of maximum deviatoric stress experienced around an advancing borehole. Furthermore, an analysis of the stress path incorporating the complete stress tensor shows that the maximum deviatoric stress does not always correlate with the typical solutions for induced stresses around a circular excavation. As a result of the limitations and uncertainties associated with traditional stress estimation methods, an integrated approach to determining the stress conditions at a given site using numerical models to simulate the loading history has been evaluated. A 2-dimensional finite element model of the Paleozoic sedimentary sequence of the eastern edge of the Michigan basin has shown that a systematic incorporation of the geological and stress history can approximate a given stress profile. Numerical models are also applied for estimating the magnitude of glacially induced stress change in the upper crust for the purpose of estimating long-term stress evolution. The framework and methodology used for numerical stress reconstruction and evolution can be included at the site characterization and engineering design stages for various types of projects, including deep geologic repositories, where estimates of in situ stress and future stress change are important. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2013-04-29 13:26:53.082

Thesis (Ph. D - Hydrology and Water Resources) - University of Arizona. / Includes bibliographical references (leaves 259-280).

Made available in DSpace on 2014-06-11T19:25:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-29Bitstream added on 2014-06-13T20:33:23Z : No. of bitstreams: 1 silva_ds_me_araca.pdf: 824748 bytes, checksum: a5191c74f89f8870aa31a3483beae50a (MD5) / O tumor venéreo transmissível canino (TVTC) é uma neoplasia transmitida entre cães saudáveis pelo contato direto de pele e/ou mucosas lesionadas. Face aos escassos estudos relacionados aos eventos celulares envolvidos nas fases de crescimento do TVTC, o presente estudo teve por objetivo identificar a presença do gene TP53 e o RNAm referente a proteína codificada, além de detectar a expressão das proteínas p53, Bcl-2 e p63 em cortes histológicos de 13 amostras de TVTC. Com relação à evolução da neoplasia, 46% das amostras foram consideradas em fase de progressão e 54% no estágio de regressão. Foram utilizadas as técnicas de hibridização in situ (ISH) e RT-PCR in situ, que demonstrou a presença do DNA homólogo ao TP53 e seu respectivo RNAm em 92,30% das amostras. A expressão das proteínas p53, p63 e Bcl-2 foram detectadas em 50%, 70% e 100% das amostras, respectivamente. A p63 foi expressa de forma evidente nas amostras em regressão, porém a p53 e a Bcl-2 não apresentaram relação com o estágio evolutivo do tumor e provavelmente não podem ser analisados como fatores de prognóstico do TVTC. Observou-se, nesse estudo que, através das técnicas de ISH e RT-PCR in situ foi possível detectar o DNA do TP53 e seus transcritos, porém esse fato não significou a transcrição da p53, devido aos baixos níveis de expressão nas análises quantitativa e qualitativa nas amostras de TVTC / The canine transmissible venereal tumor (CTVT) is transmitted by direct contact of skin or mucosal presenting lesions. In fact, few reports have been found describing the cellular immune response related to the evolution of the tumor. The objective of this study was to identify the TP53 gen and its transcription in CTVT in different stages of evolution, collected from dogs (N=13) examined at veterinary school, UNESP, Aracatuba, SP, Brasil. In addition, it was also evaluated the expression of p53, p63 and Bcl-2 in histological sections by the use of immunohistochemystry assay. The p53, p63 and Bcl-2 were evident in 50, 70 and 100% of analyzed samples. Regarding to tumor evolution, 6 out of 13 were considered in a progressive stage (46%), was list 7 out of 13 were classified in a regressive stage (54%). The use of in situ hybridization and reverse transcriptase polymerase chain reaction in situ (RT-PCR), revealed that TP53 was present in all samples and P63 was more expressed than p53. Take all results together, the real role of those marker are extremely important to understand the biological behavior and to improve therapeutic procedures for CTVT

Les simulations paralllèles sont devenues des outils indispensables dans de nombreux domaines scientifiques. Pour simuler des phénomènes complexes, ces simulations sont exécutées sur de grandes machines parallèles. La puissance de calcul de ces machines n'a cessé de monter permettant ainsi le traitement de simulations de plus en plus imposantes. En revanche, les systèmes d'I/O nécessaires à la sauvegarde des données produites par les simulations ont suivit une croissance beaucoup plus faible. Actuellement déjà, il est difficile pour les scientifiques de sauvegarder l'ensemble des données désirées et d'avoir suffisament de puissance de calcul pour les analyser par la suite. A l'ère de l'Exascale, on estime que moins de 1% des données produites par une simulation pourronts être sauvegardées. Ces données sont pourtant une des clés vers des découvertes scientifiques majeures. Les traitements in-situ sont une solution prometteuse à ce problème. Le principe est d'effectuer des analyses alors que la simulation est en cours d'exécution et que les données sont encore en mémoire. Cette approche permet d'une part d'éviter le goulot d'étranglement au niveau des I/O mais aussi de profiter de la puissance de calcul offerte par les machines parallèles pour effectuer des traitements lourds en calcul. Dans cette thèse, nous proposons d'utiliser le paradigme du dataflow pour permettre la construction d'applications in-situ complexes. Pour cela, nous utilisons l'intergiciel FlowVR permettant de coupler des codes parallèles hétérogènes en créant des canaux de communication entre eux afin de former un graphe. FlowVR dispose de suffisament de flexibilité pour permettre plusieurs stratégies de placement des processus d'analyses que cela soit sur les nœuds de la simulation, sur des cœurs dédiés ou des nœuds dédiés. De plus, les traitements in-situ peuvent être exécutés de manière asynchrone permettant ainsi un faible impact sur les performances de la simulation. Pour démontrer la flexibilité de notre approche, nous nous sommes intéressés au cas à la dynamique moléculaire et plus particulièrement Gromacs, un code de simulation de dynamique moléculaire couramment utilisé par les biologistes pouvant passer à l'échelle sur plusieurs milliers de coeurs. En étroite collaboration avec des experts du domaine biologique, nous avons contruit plusieurs applications. Notre première application consiste à permettre à un utilisateur de guider une simulation de dynamique moléculaire vers une configuration souhaitée. Pour cela, nous avons couplé Gromacs à un visualiseur et un bras haptique. Grâce à l'intégration de forces émises par l'utilisateur, celui ci peut guider des systèmes moléculaires de plus d'un million d'atomes. Notre deuxième application se concentre sur les simulations longues sur les grandes machines parallèles. Nous proposons de remplacer la méthode native d'écriture de Gromacs et de la déporter dans notre infrastructure en utilisant deux méthodes distinctes. Nous proposons également un algorithme de rendu parallèle pouvant s'adapter à différentes configurations de placements. Notre troisième application vise à étudier les usages que peuvent avoir les biologistes avec les applications in-situ. Nous avons développé une infrastructure unifiée permettant d'effectuer des traitements aussi bien sur des simulations intéractives, des simulations longues et en post-mortem. / Parallel simulations have become a powerwul tool in several scientific areas. To simulate complex phenomena, these simulations are running on large parallel machines. The computational power available on those machines has increased a lot in the last years allowing to simulate very large models. Unfortunately, the I/O capabilities necessary to save the data produced by simulation has not grown at the same pace. Nowadays, it is already difficult to save all the needed data and to have enough computational power to analyse them afterwards. At the exascale time frame, it is expected that less than 1% of the total data produced by simulations will be saved. Yet, these data may lead to major discoveries. In-situ analytics are a promising solution to this problem. The idea is to treat the data while the simulation is still running and the data are in memory. This way, the I/O bottleneck is avoided and the computational power avaible on parallel machines can be used as well for analytics. In this thesis, we propose to use the dataflow paradigm to enable the construction of complex in-situ applications. We rely on the FlowVR middleware which is designed to couple parallel heterogeneous codes by creating communication channels between them to form a graph. FlowVR is flexible enough to allow several placement strategies on simulation nodes, dedicated cores or dedicated nodes. Moreover, in-situ analytics are executed asynchronously leading to a low impact on the simulation performances. To demonstrate the flexibility of our approach, we used Gromacs, a commonly used parallel molecular dynamic simulation package, as application target. With the help of biology experts, we have built several realistic applications. The first one is allowing a user to steer a molecular simulation toward a desired state. To do so, we have couple Gromacs with a live viewer and an haptic device. The user can then apply forces to drive molecular systems of more than 1 million atoms. Our second application focus on long simulation running in batch mode on supercomputers. We replace the native writing method of Gromacs by two methods in our infrastructure. We also propose a implemented a flexible rendering algorithm able to able to various placement strategies. Finally, we study the possible usage o biologists with our infrastructure. We propose a unifed framework able to run treatments on interactive simulation, long simulations and in post-process.

Orientadores: Pablo Agustin Vargas, Lynne Bingle / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T01:09:27Z (GMT). No. of bitstreams: 1 Silva_AndreiaAparecidada_D.pdf: 22491420 bytes, checksum: 91def4321f81cbc12963ed48ee86d77d (MD5) Previous issue date: 2009 / Resumo: Introdução: Inúmeras lesões de origem infecciosa, cística, neoplásica e inflamatória foram reportadas nas glândulas salivares de pacientes HIV+. Objetivos: Os objetivos deste trabalho foram analisar e comparar a resposta do sistema imune inato (proteínas da família PLUNC) em glândulas salivares maiores, provenientes de pacientes autopsiados com AIDS e sem AIDS (grupo controle) no Departamento de Patologia da Faculdade de Medicina da Universidade Estadual de São Paulo (FMUSP) no período de 1996 a 2000. Material e Métodos: Os pacientes autopsiados foram divididos em 05 grupos: grupo 01- controle (pacientes HIV negativos), grupo 02- HIV+ sem alterações nas glândulas salivares maiores, grupo 03- (micobacteriose), grupo 04 (citomegalovirose) e grupo 05 (sialadenite) para a realização de reações de imunohistoquímica para os anticorpos SPLUNC 1, SPLUNC 2 A, SPLUNC 2B e LPLUNC 1. Para o grupo controle foi realizado técnica de hibridização in situ para SPLUNC 2. Resultados: a média de idade dos pacientes selecionados para o grupo controle foi de 60,92 anos + 9,48 anos enquanto que a média de idade dos pacientes HIV positivos foi de 37,75 anos + 11,11. Nos casos de micobacteriose e citomegalovirose foi observada maior intensidade de marcação nas regiões próxima a área de infecção, quando comparada com áreas na periferia da lesão para os anticorpos SPLUNC 2 A e 2B. O anticorpo LPLUNC 1 foi positivo apenas nos ductos salivares e apresentou positividade em 42,22%, 51,06% e 63,88% para as glândulas parótida, submandibular e sublingual respectivamente. Com relação à hibridização in situ, foi observado positividade em todos os casos. Conclusão: a família de proteínas PLUNC pode ter papel fundamental na proteção dos organismos frente a agentes infecciosos, no entanto são necessários maiores estudos. / Abstract: Objectives: The aim of this study was to determine the expression of PLUNC proteins in major salivary glands (MSG) of AIDS patients with or without infectious conditions and non-HIV patients using post-mortem material. Methods: Sex, age, CD4 cell count, and clinical history were obtained retrospectively from the clinical records of all patients (n=63). We analysed the expression of PLUNCs (SPLUNC1, SPLUNC2, LPLUNC1) using immunohistochemistry in parotid (n=45), submandibular (n=47) and sublingual gland (n=37) samples of AIDS patients [30 with normal histology, 21 with mycobacteriosis, 14 with cytomegalovirus (CMV) infection, 30 with chronic nonspecific sialadenitis, and 30 HIV-negative controls. In situ hybridization (ISH) for SPLUNC2 in the MSG of the HIVnegative group was performed. Immunoreactivity was assessed as positive or negative. Results: The mean age of the patients who died of AIDS (n=63) and CD4 cell count (n=44) were 37 years and 63 cells microL(-1), respectively. The mean age of the HIV negative patients was 61 years. SPLUNC 1 expression was detected in the mucous acini of submandibular and sublingual glands, and SPLUNC2 was seen in the serous cells of the MSG. LPLUNC 1 expression was only positive in the salivary ducts of the MSG. There was a higher expression of SPLUNC2 in AIDS patients with CMV infection and mycobacteriosis when compared with all other groups. The intensity of staining for SPLUNC2 was greater around the lesions than the peripheral ones. There were no significant differences between control subjects and AIDS patients without histologic alterations or with chronic nonspecific sialadenitis. ISH for SPLUNC 2 showed perinuclear positivity in the serous cells in all HIV-negative cases. Conclusions: SPLUNC1 and LPLUNC1 proteins were similarly expressed in the MSG of AIDS patients and non-HIV patients. CMV infection and mycobacteriosis increase SPLUNC2 expression in serous cells in the MSG of AIDS patients. Further studies are needed to understand the biological processes involved in SPLUNC2 expression in the MSG infected by CMV and mycobacteriosis. / Doutorado / Patologia / Doutor em Estomatopatologia

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22127号 / 工博第4657号 / 新制||工||1726(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 安田 秀幸, 教授 辻 伸泰, 教授 宇田 哲也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

"Conventional manufacturing methods are sub-optimal for nano-composites fabrication. Inhomogeneous dispersion of the secondary phase and scalability issues are the main issues. This work focuses on an innovative method where the reinforcement is formed in-situ in the melt. It involves the reaction of the molten aluminum with a nitrogen- bearing gas injected through the melt at around 1273 K. AlN particles are expected to form through this in situ reaction. A model has been developed to predict the amount of reinforced phase. Experiments have been carried out to confirm the feasibility of the process and the mechanism of AlN formation discussed. The detrimental effect of oxygen in the melt which hinders the nitridation reaction has been proved. The effect of process times and the addition of alloying elements (Mg and Si) have also been investigated."

The interfacial reaction of Ni with Si, Si₀.₇₅Ge₀.₂₅, and Ge at 400°C has been investigated. A uniform epitaxial NiSi film was obtained at 400°C for Ni-Silicidation on Si using rapid thermal annealing method. Similarly, uniform film of NiGe was formed at 400°C for Ni reaction with Ge. Whereas using in situ annealing at 400°C, Ni₃Ge₂ and NiGe were observed. For the interfacial reaction of Ni with relaxed Si₀.₇₅Ge₀.₂₅ films rapid thermal annealed at 400°C, a mixed layer consisting of Ni₃(Si₁₋xGex)₂, Ni(Si₁₋yGey), and Si₁₋zGez (z>y>x) was formed; whereas only Ni₃(Si₁₋xGex)₂ and Ni(Si₁₋yGey>) were observed by in situ annealing. / Singapore-MIT Alliance (SMA)