Image sensors play a vital role in many image sensing and capture applications. Among the various types of image sensors, complementary metal oxide semiconductor (CMOS) based active pixel sensors (APS), which are characterized by reduced pixel size, give fast readouts and reduced noise. APS are used in many applications such as mobile cameras, digital cameras, Webcams, and many consumer, commercial and scientific applications. With these developments and applications, CMOS APS designs are challenging the old and mature technology of charged couple device (CCD) sensors. With the continuous improvements of APS architecture, pixel designs, along with the development of nanometer CMOS fabrications technologies, APS are optimized for optical sensing. In addition, APS offers very low-power and low-voltage operations and is suitable for monolithic integration, thus allowing manufacturers to integrate more functionality on the array and building low-cost camera-on-a-chip. In this thesis, I explore the current state-of-the-art of CMOS APS by examining various types of APS. I show design and simulation results of one of the most commonly used APS in consumer applications, i.e. photodiode based APS. We also present an approach for technology scaling of the devices in photodiode APS to present CMOS technologies. Finally, I present the most modern CMOS APS technologies by reviewing different design models. The design of the photodiode APS is implemented using commercial CAD tools.

Les chimiokines sont des petites protéines secrétées dont la fonction principale est la stimulation de la migration de cellules immunitaires vers différents organes et tissus. Elles sont souvent impliquées lors des maladies inflammatoires, auto-immunes et des cancers. Ainsi, les chimiokines et leurs récepteurs couplés aux protéines G (RCPG) sont la cible pharmacologique de plusieurs molécules, actuellement testées en essais cliniques. Nous avons pris comme modèle, lors de notre étude, le récepteur atypique CXCR7. Ce récepteur est dit atypique, car il ne signalise pas via la voie classique des protéines G, mais plutôt via la voie de la β-arrestine. CXCR7 est impliqué dans de nombreux cancers, favorise la progression métastatique et est un co-récepteur pour le virus de l’immunodéficience humaine (VIH). Cependant, aucune donnée sur son mode de liaison avec ses ligands CXCL11/ITAC et CXCL12/SDF-1 n’existe à date. Nous pensons que cette information est essentielle pour le développement efficace d’agonistes et d’antagonistes, et nous nous sommes intéressés à identifier les résidus essentiels à la liaison des deux ligands de CXCR7 et à son activation par ces derniers. Pour cela, nous avons créé une série de mutants par substitution ou délétion d’acides aminés de la partie N-terminale, des boucles extracellulaires et des domaines transmembranaires du récepteur. Nous avons testé leur marquage en surface cellulaire par cytométrie en flux, leur liaison des deux ligands par expériences de radio-liaison, et leur capacité à recruter la β-arrestine en réponse aux ligands par essais BRET. Les résultats obtenus ont permis d’identifier des résidus importants à l’interaction des systèmes CXCR7/SDF-1 et CXCR7-ITAC et suggèrent des modes de liaison à CXCR7 différents entre ITAC et SDF-1. Tout comme la liaison d’ITAC à son autre récepteur CXCR3, sa liaison à CXCR7 suivrait le mode conventionnel de liaison en deux étapes des récepteurs de chimiokines. Cependant, la liaison de SDF-1 à CXCR7 suivrait un autre mode de liaison, contrairement à sa liaison à son autre récepteur, CXCR4. / Chemokines are small secreted proteins whose major function is to stimulate the migration of immune cells to different organs and tissues. They are often involved in inflammatory and auto-immune diseases as well as cancers. Thus, chemokines and their G proteins Coupled Receptors (GPCR) are the pharmacological target of multiples molecules, currently tested in clinical trials. The model of our study is the atypical receptor CXCR7. This receptor is called atypical because it doesn’t signalize through the classical G protein pathway but rather signalizes through the β-arrestin pathway. CXCR7 is involved in many cancers, promotes metastatic progression and is a co-receptor for human immunodeficiency virus (HIV). However, there are, to date, no data concerning its binding mode to its ligands CXCL11/ITAC and CXCL12/SDF-1. We think that this information is crucial for the efficient development of agonists and antagonists and thus decided to identify the residus that are important for the binding of the two ligands of CXCR7 to the receptor and its subsequent activation. For that, we created a set of mutants by substitution or deletion of amino acids of the N-terminus, extracellular loops and transmembrane domains of the receptor. We then tested their surface expression by antibody staining and flow cytometry, their binding of the two ligands by binding assays and their capability to recruit β-arrestin in response to the ligands by BRET assays. The results obtained allowed us to identify important residues for the interaction of the systems CXCR7/SDF-1 and CXCR7/ITAC. They also suggest different binding modes of the chemokines ITAC and SDF-1 to CXCR7. Just like the binding of ITAC to its other receptor CXCR3, the binding mode of ITAC to CXCR7 follows the conventional two steps binding model of chemokine receptors. However, the binding of SDF-1 to CXCR7 follows another binding mode than the classical two step model, unlike its binding to its other receptor CXCR4.

This thesis deals with the development and application of Monte Carlo simulations to study electron transport in bulk GaN in the wurtzite crystal structure and the properties of field effect transistors made from the material. There is a particular emphasis on transport in the high electric field regime and transistors operating at high voltages. The simulation model includes five sets of non-parabolic conduction band valleys which can be occupied by electrons during high field transport. The effects on electron transport of impurities and the relevant phonon scattering mechanisms have been considered. Results for electron transport at both low and high electric field are presented and compared with the properties of GaN in the zincblende structure, of other group-III nitride semiconductors, and of GaAs. The dependence of the transport properties on the material parameters is discussed and also with regard to the temperature, donor concentration and electric field magnitude and direction. The transport properties of electrons in wurtzite GaN n+-i(n)-n+ diodes are also explored, including the effect of the upper valleys and the temperature on hot electron transport. Simulations have also been carried out to model the steady-state and transient properties of GaN MESFETs that have recently been the subject of experimental study. It has been suggested that traps have a substantial effect on the performance of GaN field effect transistors and we have developed a model of a device with traps to investigate this suggestion. The model includes the simulation of the capture and release of electrons by traps whose charge has a direct effect on the current flowing through the transistor terminals. The influence of temperature and light on the occupancy of the traps and the /- V characteristics are considered. It is concluded that traps are likely to play a substantial role in the behaviour of GaN field effect transistors. Further simulations were performed to model electron transport in AlGaN/GaN hetero-junction FETs. So called HFET structures with a 78 nm Alo.2Gao.8N pseudomorphically strained layer have been simulated, with the inclusion of spontaneous and piezoelectric polarization effects in the strained layer. The polarization effects are shown to not only increase the current density, but also improve the electron transport by inducing a higher electron density close to the positive charge sheet that occurs in the channel.

In dieser Arbeit werden hochgeladene, mit einer Electron Beam Ion Trap produzierte Ionen für die Erforschung des Elektroneneinfangs von Oberflächen und Gasen eingesetzt. Die Untersuchungen mit Gastargets konzentrieren sich auf die Energieabhängigkeit der Verteilung der K-Schalen-Röntgenstrahlen, die nach Elektroneneinfang in Rydberg-Zustände von Ar-17+ und Ar-18+ Ionen am Ende einer Kaskade von Elektronenübergängen entstehen. Die Ionen werden von der Ionenquelle mit einer Energie von 2 keV/u extrahiert, ladungsselektiert und anschließend bis auf 5 eV/u abgebremst, um dann mit einem Argon Gastarget zu interagieren. Für abnehmende Stoßenergien wird eine Verschiebung des Elektroneneinfangs in Zustände mit niedrigen Drehumpulsquantenzahlen beobachtet. Zum Vergleich wird auch die K-Schalen-Röntgenstrahlung auf Grund des Elektroneneinfangs bei Ar-17+ und Ar-18+ von dem Restgas in der Falle gemessen. Dabei wird eine Diskrepanz zu den Resultaten der Extraktionsversuche festgestellt. Mögliche Erklärungen werden diskutiert. In den Untersuchungen zum Elektroneneinfang von Oberflächen werden hochgeladene Ionen von der Ionenquelle mit Energien von 2 bis 3 keV/u extrahiert, ladungsselektiert und auf Targets gelenkt. Diese bestehen aus Siliziumnitridmembranen mit einer Vielzahl nanometergroßer Löcher, welche mittels eines fokussierten Ionenstrahls in Kombination mit ionenstrahlinduzierter Abscheidung dünner Filme erstellt werden. Es werden hierbei Lochdurchmesser von 50 bis 300 nm mit Formfaktoren von 1:5 bis 3:2 erreicht. Bei den hochgeladenen Ionen handelt es sich um Ar-16+ und Xe-44+. Nach dem Transport durch die Kapillare passieren die Ionen einen elektrostatischen Ladungstrenner und werden detektiert. Der Anteil des Elektroneneinfangs von den Wänden der Löcher ist weitaus geringer als Modellberechnungen vorhersagen. Die Resultate werden an Hand eines Kapillareffekts zur Ionenleitung diskutiert. / In this study highly charged ions produced in Electron Beam Ion Traps are used to investigate electron capture from surfaces and gases. The experiments with gas targets focus on spectroscopic measurements of the K-shell x-rays emitted at the end of radiative cascades following electron capture into Rydberg states of Ar-17+ and Ar-18+ ions as a function of collision energy. The ions are extracted from an Electron Beam Ion Trap at an energy of 2 keV/u, charge-selected and then decelerated down to 5 eV/u for interaction with an argon gas target. For decreasing collision energies a shift to electron capture into low orbital angular momentum capture states is observed. Comparative measurements of the K-shell x-ray emission following electron capture by Ar-17+ and Ar-18+ ions from background gas in the trap are made and a discrepancy in the results compared with those from the extraction experiments is found. Possible explanations are discussed. For the investigation of electron capture from surfaces, highly charged ions are extracted from an Electron Beam Ion Trap at energies of 2 to 3 keV/u, charge-selected and directed onto targets comprising arrays of nanoscale apertures in silicon nitride membranes. The highly charged ions implemented are Ar-16+ and Xe-44+ and the aperture targets are formed by focused ion beam drilling in combination with ion beam assisted thin film deposition, achieving hole diameters of 50 to 300 nm and aspect ratios of 1:5 to 3:2. After transport through the nanoscale apertures the ions pass through an electrostatic charge state analyzer and are detected. The percentage of electron capture from the aperture walls is found to be much lower than model predictions and the results are discussed in terms of a capillary guiding mechanism.

Au cours du traitement d'une tumeur avec des ions légers, la position du pic de Bragg doit être connue avec précision. Une fraction importante des ions incidents subissent des collisions nucléaires avec les noyaux cibles conduisant à l'émission de particules promptes qui peuvent être porteuses d'informations sur le parcours des ions. Ce travail, qui se concentre sur les gamma prompts, montre que le rendement en profondeur de ces émissions est fortement corrélé au parcours des ions et que les taux de comptage mesurés permettent d'envisager un système d'imagerie réaliste, fonctionnant en temps réel. Dans ce but, nous avons réalisé des expériences au GANIL et au GSI avec un détecteur collimaté placé perpendiculairement à l'axe du faisceau et la technique du temps de vol a été utilisée pour réduire le bruit de fond induit par les neutrons et les particules chargées. Des simulations Geant4 ont été réalisées pour concevoir le dispositif expérimental et interpréter les données. Un accord qualitatif entre les simulations et l'expérience est observé pour la quantité d'énergie déposée dans le détecteur et pour la forme du spectre de temps de vol. Cependant, des divergences apparaissent pour le rendement de gamma prompts et la distribution en profondeur des gamma détectés. Ces divergences sont discutées, principalement en termes de modèles de physique nucléaire qui doivent être améliorés. Après avoir sélectionné les modèles physiques offrant les simulations les plus en accord avec les mesures, des études concernant les lieux d'émissions des gamma prompts et l'influence de la diffusion dans la cible ont été réalisés afin de déterminer l'impact sur la corrélation avec le parcours des ions / During the treatment of a tumor with light ions, the Bragg peak location must be accurately known. A significant fraction of the incident ions undergo nuclear collisions with the target nuclei leading to the prompt emission of particles which may carry information on the ion path. This work, which focuses on prompt gamma, shows that the depth profile of these emissions is highly correlated to the ions path and the measured counting rates allow to consider a realistic imaging system, operating in real time. For that purpose, we performed experiments at GANIL and at GSI with a collimated detector placed perpendicular to the beam axis and the time of flight technique was used in order to reduce the noise induced by neutrons and charged particles. Geant4 simulations were performed for the experimental design and data interpretation. A qualitative agreement between simulations and experiment is observed for the amount of energy deposited in the detector and the shape of the time of flight spectrum. However, discrepancies appear for the prompt gamma yield and the depth distribution of gamma detected. These discrepancies are discussed, mainly in terms of nuclear physics models that must be improved. After selecting the physical models which lead to the best agreement between simulations and measurements, studies on the location of prompt gamma emission and on the influence of diffusion in the target were performed to determine the impact on the correlation with the ion path

Os alcaloides têm apresentado diversas atividades biológicas. Entre eles, a montanina vem demonstrando um bom desempenho nesse sentido, como, atividade antioxidante, ação inibitória do crescimento de culturas bacterianas e importante atividade de inibição do crescimento de linhagens tumorais. Atualmente, não existem muitos relatos da sua caracterização ou métodos analíticos quantitativos disponíveis na literatura para atribuir seu teor. Assim, após purificação, a caracterização da montanina foi realizada por calorimetria exploratória diferencial (DSC), espectroscopia na região do ultravioleta (UV), infravermelho (IV), espectrometria de massas (CLAE-EM), ressonância magnética nuclear de hidrogênio (RMN1H), de carbono (RMN13C) e em 2D homo e heteronucleares tais como COSY (nJH-H, escalar), NOESY (nJH-H, dipolar), HSQC (1JH-C, escalar) e HMBC (nJH-C, escalar). Na sequência, foram desenvolvidos métodos empregando a cromatografia líquida de alta eficiência (CLAE) acoplada aos detectores ultravioleta e aerossol carregado (CLAE- UV/DAC) para a quantificação da montanina. Os mesmos foram validados, avaliando-se os parâmetros de especificidade, linearidade, intervalo, limite de detecção, limite de quantificação, precisão, exatidão e robustez. Os resultados obtidos foram avaliados por estatística descritiva e os métodos comparados pelo resultado da análise de variância (ANOVA). Desse modo, foram desenvolvidos procedimentos que podem ser aplicados para aprimorar o controle de qualidade, contribuindo para assegurar a eficácia terapêutica da montanina. / Alkaloids have several biological activities. Among them, montanine have shown antioxidant activity, inhibitory effect on bacterial growth and important activity inhibiting growth of some tumor cell lines. Currently, there are a few reports about its characterization as well as quantitative analytical methods to determine its purity. Thus, after a purification step, montanine will be characterized by its differential scanning calorimetry (DSC), ultraviolet spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (HPLC-MS), nuclear magnetic resonance of proton (NMR1H), carbon (NMR13C) and 2D homo and heteronuclear such as COSY (nJH-H, scalar), NOESY (nJH-H, dipolar), HSQC (1JH-C, scalar) and HMBC (nJH-C, scalar). Further, quantitation methods will be developed employing high-performance liquid chromatography (HPLC) coupled with ultraviolet and charged aerosol detectors (HPLC-UV/CAD). These methods will be validated regarding the parameters specificity, linearity, range, detection limit, quantitation limit, precision, accuracy and robustness. The results will then be evaluated by descriptive statistics and the developed methods will be compared using analysis of variance (ANOVA). Therefore, tests will be developed that can be used to improve quality control, helping to ensure the therapeutic efficacy of montanine.

Orientador: Carlos Gilberto Raetano / Banca: Wilson Badiali Crocomo / Banca: Hamilton Humberto Ramos / Resumo: A pulverização é a mais importante técnica de aplicação de produtos fitossanitários na cultura do crisântemo. A otimização dessa tecnologia pode ser obtida com a transferência de carga elétrica às gotas, as quais são fortemente atraídas pelas plantas, minimizando a exposição dos aplicadores e as perdas para o ambiente. O trabalho objetivou avaliar a deposição das gotas de pulverização dotadas de carga elétrica (eletrostática) em comparação à técnica de pulverização convencional, bem como a eficiência dessas técnicas no controle de Tetranychus urticae na cultura do crisântemo. Os experimentos foram conduzidos no delineamento inteiramente ao acaso. No experimento para avaliação da deposição da pulverização foram realizados oito tratamentos com quatro repetições. Cada repetição foi representada por doze plantas às quais foram afixados papéis do tipo mataborrão na superfície abaxial e adaxial dos folíolos e em duas posições da planta: ápice e base. Foram utilizadas quatro pontas de pulverização (TXVK-3, AXI 110015, AXI 12002 TWIN e AXI 11003) combinadas às técnicas de pulverização eletrostática e convencional. Um corante marcador (Rodamina B) foi pulverizado na proporção de 5 gramas por 100 litros d’água em cada um dos tratamentos. Os depósitos do corante marcador foram quantificados por 2 fluorometria. A eficiência dos tratamentos no controle do ácaro-rajado foi estabelecido pela combinação do tipo de ponta (AXI 110015, AXI 12002 TWIN e TXVK-3), da técnica de pulverização (eletrostática e convencional) e do produto para o controle do ácaro (azociclotina e espirodiclofeno, nas doses de 25 e 4,8 mL de i.a. por 100 L d’água, respectivamente) mais dois tratamentos adicionais (testemunhas). Avaliações da população do ácaro foram realizadas antes e aos 3, 7, 11 e 15 dias após a pulverização pela contagem... (Resumo completo, clicar acesso eletrôncio abaixo) / Abstract: Spraying is the most important pesticide application technique for healthy development of chrysanthemum plants. The optimization of this technology can be obtained with the transference of the electric charge in the droplets. These droplets are strongly attracted by plants, minimizing the workers exposition as well as loss to the environment. The research aims to evaluate the spray deposition with electric charge (electrostatic) compared to conventional application technique. It also aims to evaluate the efficiency of these techniques in the Tetranychus urticae control of chrysanthemum plants. The experiments were carried out entirely at random. In the deposition experiment eight treatments were set with four repeats. Each repeat was represented by twelve chrysanthemum plants. Blotting paper was placed on the abaxial and adaxial surfaces of two leaves in different positions of the plants: top and bottom. Four spray nozzles (TXVK-3, AXI 110015, AXI 12002 TWIN and AXI 11003) were combined to different spraying techniques (electrostatic and conventional). A tracer dye (Rodamina B) was applied in the ratio of 5 grams per 100 L of water in each one of the treatments. Deposits of the tracer dye were quantified by fluorometery. The efficiency of treatments in the control of spider mite was established by combination of spray nozzle type (AXI 110015, AXI TWIN and TXVK-3), with different application techniques and the acaricides (azocyclotin and espirodiclofen, at the dosages 25 and 4,8mL of a.i. per 100 L of water, respectively), plus two additional treatments (checks). The evaluations of spider mite population were realized until and at 3, 7, 11 and 15 days after spraying by counting the number of mites in pre-established area of 1 4 cm2 in the top leaves of the plants. The percentage of efficiency of the control was calculated by the adapted formula of Henderson e Tilton... (Complete abstract click electronic access below) / Mestre

Ce travail de thèse a pour objet de contribuer à la compréhension de la déformation des assemblages combustibles REP équipés de composants en alliages de zirconium (Zy-4 ou M5). En particulier, nous nous sommes intéressés à l’accélération de croissance, corrélée à l’apparition d’un type de défaut d’irradiation : les boucles à composante <c>. Des irradiations aux particules chargées nous ont permis de reproduire ces évolutions microstructurales et d’étudier leur représentativité. La morphologie du dommage primaire n’a ainsi que peu d’impact sur la microstructure de boucles <c> tandis que le taux de création de dommage (tout comme la température) semble jouer un rôle majeur. Par ailleurs, la dose seuil pour la nucléation des boucles <c> apparaît étroitement liée à la cinétique de croissance des amas lacunaires et des germes de boucles. Cette cinétique peut être influencée par le taux de création de dommage, les éléments d’alliages, mais également la contrainte ou la présence d’hydrogène (introduit dans le matériau lors de l’oxydation en réacteur). Ce travail a ainsi exploré de manière approfondie l’effet d’une contrainte appliquée dans les domaines d’élasticité et de plasticité ainsi que l’impact de l’hydrogène absorbé sur la nucléation et la croissance des boucles <c>. Conformément au mécanisme SIPA proposé dans la littérature, nous avons observé un effet de la contrainte sur les boucles <c>. Par ailleurs, cette étude met en évidence que l’hydrogène en solution et / ou sous forme d’hydrures influence significativement la nucléation et la croissance des boucles <c>. / The aim of this PhD work is to have a better understanding of axial elongation of the PWR fuel assemblies manufactured in zirconium alloys (Zy-4 or M5). More specifically, we focused on the growth acceleration of these assemblies, clearly correlated to the nucleation of specific irradiation defects: the c-loops. Irradiations by charged particles were performed in order to reproduce the microstructure evolution and to study its representativeness. Thus, primary damage morphology has no impact on the c-loop microstructures where as the damage creation rate (like the temperature) seems to play a major role. Moreover, the nucleation dose for c-loops appears clearly correlated to the nuclei and vacancy clusters growth kinetics. This kinetics could be influenced by the damage creation rate, the alloying elements, but also by an applied stress or the hydrogen content (which can be introduced during oxidation in reactor). Thus, this work has explored the effect of an applied stress (in the elasticity or plasticity domain) and the impact of the hydrogen pick-up on the nucleation and growth of c-loops. In accordance with the SIPA mechanism described in the literature, we observed an effect of the applied stress on the c-loop microstructures. Moreover, this study clearly shows an impact of hydrogen in solid solution and as precipitated hydrides on the nucleation and growth of c-loops.

Counselor educators foster the multicultural counseling competence of counselors-in-training; however, counselor educators face challenges that include emotionally charged exchanges that may might impact counselor educators' relationship with students. The purpose of this transcendental phenomenological study was to investigate counselor educators' experiences with emotionally charged exchanges related to teaching multicultural counseling. The ecological systems theory was used as a conceptual framework. A purposeful sample of 4 counselor educators from Council for Accreditation of Counseling and Related Educational Programs-accredited counselor education programs in the United States shared their knowledge of these emotionally charged exchanges through semistructured phone interviews in their natural settings. The data gathered underwent analysis following the descriptive phenomenological method, and revealed the essence of counselor educators' lived experiences: ever-present conflicting emotions and tension, with peaks of feeling exposed, inadequate, and satisfied after intentionally evoking students' emotions. Counselor educators can use the results of this study to alter their pedagogy and empower their students to develop their multicultural counseling competence more fully. Improved multicultural counseling competence might improve the treatment provided to a diverse range of clients and reduce treatment disparities.

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