Τα τελευταία χρόνια η ανάγκη για αναλογικά ολοκληρωμένα κυκλώματα με χαμηλή τάση τροφοδοσίας και χαμηλή ισχύ γίνεται κάτι περισσότερο από επιτακτική. Ο βασικότερος λόγος για την ανάγκη αυτή είναι η ραγδαία ανάπτυξη από φορητές ηλεκτρονικές συσκευές για εφαρμογές πολυμέσων (laptops, netbooks, mobiles) έως ολοκληρωμένων συστημάτων βιοιατρικών εφαρμογών. Μάλιστα σε πολλές περιπτώσεις απαιτείται αυτές οι ηλεκτρονικές συσκευές να έχουν δυνατότητα διασύνδεσης σε ασύρματα δίκτυα (WLANs) και επομένως επιβάλλεται η ενσωμάτωση συστημάτων πομποδεκτών. Έτσι, οι απαιτήσεις για όσο το δυνατόν μικρότερη κατανάλωση και επομένως χαμηλότερη τροφοδοσία είναι επιβεβλημένες. Ένα από τα βασικότερα «δομικά» κυκλώματα σχεδίασης αναλογικών κυκλωμάτων είναι οι διαφορικοί ενισχυτές τάσης. Στην παρούσα διατριβή παρουσιάζονται πλήρεις λύσεις διαφορικών ενισχυτών χαμηλής τάσης τροφοδοσίας σε τυπική CMOS τεχνολογία των 0.35μm και 0.18μm. Οι προτεινόμενοι ενισχυτές σχεδιάστηκαν με την τεχνική οδήγησης τρανζίστορ από το υπόστρωμα (Bulk-driven technique). Αρχικά σχεδιάστηκαν διαφορικοί ενισχυτές τάσεις με τοπολογία αρνητικής αντίστασης στην βαθμίδα εισόδου. Με τον τρόπο αυτό έγινε αύξηση της μικρής διαγωγιμότητας εισόδου που παρουσιάζει η τεχνική οδήγησης τρανζίστορ από το υπόστρωμα. Έτσι, προέκυψαν πρωτότυπες δομές ενισχυτών με χαμηλή τροφοδοσία μέχρι και 0.8V. Οι επιδόσεις των ενισχυτών χαρακτηρίστηκαν από κατάλληλες προσομοιώσεις αλλά και από πειραματικές μετρήσεις καθώς κατασκευάστηκε ολοκληρωμένο κύκλωμα ενισχυτή. Η σύγκλιση των αποτελεσμάτων των προσομοιώσεων με των πειραματικών απέδειξε πως τόσο τα προτεινόμενα κυκλώματα όσο και η ίδια η τεχνική σχεδίασης αποτελούν σημαντική λύση όπου απαιτούνται διαφορικοί ενισχυτές τάσης χαμηλής τροφοδοσίας. Στη συνέχεια σχεδιάστηκε βαθμίδα διαφορικού ακόλουθου τάσης με την τεχνική οδήγησης τρανζίστορ από το υπόστρωμα και τροφοδοσία 1V. Η βαθμίδα αυτή χρησιμοποιήθηκε ως διαφορική βαθμίδα εισόδου διαφορικού ενισχυτή τάσης με τροφοδοσία 1V. Ο ενισχυτής αυτός λειτουργεί για μεταβολή του κοινού σήματος εισόδου μεταξύ των άκρων της τροφοδοσίας. Ο ακόλουθος τάσης τροποποιήθηκε κατάλληλα ώστε να λειτουργεί με τροφοδοσία 0.5V και χρησιμοποιήθηκε ως διαφορική βαθμίδα εισόδου σε διαφορικό ενισχυτή τάσης ίδιας τροφοδοσίας. Και οι δυο προτεινόμενες τοπολογίες ενισχυτών αποτελούν πλήρεις λύσεις για εφαρμογές ενισχυτών τάσης με χαμηλή και πολύ χαμηλή τροφοδοσία αντίστοιχα. Τέλος με την τεχνική οδήγησης τρανζίστορ από το υπόστρωμα σχεδιάστηκε ενισχυτής μεταβλητού κέρδους. Για το σκοπό αυτό αναπτύχθηκε τεχνική γραμμικής μεταβολής διαγωγιμότητας διαγωγών. Ο ενισχυτής μεταβλητού κέρδους που σχεδιάστηκε λειτουργεί με τροφοδοσία 0.8V ενώ το κέρδος έχει εύρος μεταβολής 17dB και μπορεί να ενσωματωθεί σε βρόχο αυτομάτου ελέγχου κέρδους χαμηλής τροφοδοσίας. Για το σκοπό αυτό σχεδιάστηκαν με την τεχνική οδήγησης τρανζίστορ από το υπόστρωμα και δυο κυκλώματα τετραγωνικής συνάρτησης με τροφοδοσία 0.8V και 0.5V αντίστοιχα. / In recent years the need for analog integrated circuits with low-voltage and low-power is more than urgent. The main reason for this need is the rapid growth of portable electronic devices for multimedia applications (laptops, netbooks, mobiles, etc.) and even more for biomedical devices applications. In many cases, these electronic devices provide connectivity to wireless networks (WLANs) and therefore they incorporate transceiver systems. Thus, requirements such as low-voltage and low-power are a necessity. One of the basic analog “building blocks” for circuit design is differential voltage amplifiers. This thesis presents complete solutions for low-voltage differential amplifiers in standard CMOS technology of 0.35μm and 0.18μm. The proposed amplifiers were designed with bulk-driven technique. In the first place are designed differential voltage amplifiers that include input stage with negative resistance circuitry. This way the proposed amplifiers improve the small input transconductance due to bulk-driven transistors. Thus, novel amplifier structures are obtained with a voltage supply equal even to 0.8V. The amplifiers performance is characterized both through simulation and experimental results. The convergence of simulation and experimental results demonstrate that the proposed amplifiers circuits designed with bulk-driven technique are significant solution in the design of low-voltage amplifiers. In the next step a differential bulk-driven voltage follower is designed with 1V voltage supply. The proposed follower is used as a differential input stage for a differential voltage amplifier with the same voltage supply. The proposed amplifier is capable to operate rail-to-rail for common mode input signals. Also, the proposed voltage follower is modified in order to operate in extreme voltage supply of 0.5V. The modified voltage follower is used, again, as a differential input stage for a differential voltage amplifier while the whole amplifier used a voltage supply equal to 0.5V. Both proposed amplifiers topologies that use bulk-driven differential voltage followers as input stages are complete solutions for low-voltage and ultra low-voltage amplifiers applications. Finally, a new technique for linear transconductance variation, applicable in any kind of transconductor, is introduced. The proposed technique is used to build a bulk-driven variable gain amplifier (VGA). The proposed VGA operate with 0.8V voltage supply while produce a gain range variation equal to 17dB. The amplifier could incorporate in an automatic gain control loop (AGC) for low-voltage applications. For this purpose, two bulk-driven voltage squarers circuits with voltage supply 0.8V and 0.5V was also proposed.

Les systèmes micro-opto-électro-mécaniques (MOEMS) représentent un atout considérable pour les technologies de demain et démontrent régulièrement leur capacité d'innovation dans tous les domaines de recherches. L'astronomie en profite déjà à travers l'optique adaptative et leur versatilité a récemment permis de développer un nouveau spectro-imageur BATMAN qui verra sa première lumière au Telescopio Nazionale Galileo (TNG) à La Palma (Iles Canaries). Le code de contrôle du MOEMS permettant l'automatisation de l'acquisition des spectres a été le point de départ de mon travail au LAM.La partie principale de ce manuscrit traite d'une seconde application imaginée en associant les MOEMS à un matériau photochromique développé à Polytecnico di Milano (Italie) qui peut prendre deux états différenciés par leur transparence. Le MOEMS, initialement utilisé pour la projection d'image, permet de moduler la dose d'énergie lumineuse projeté sur la plaque photochromique qui répond en s'éclaircissant progressivement. Ce procédé permet donc d'enregistrer des images en niveau de gris sur la plaque et notamment des hologrammes générés par ordinateur (CGH) utilisés en métrologie optique. Actuellement, les CGHs utilisés sont binaires, mais notre procédure permet d'enregistrer des CGHs quantifiés en amplitude avec une résolution de 13,68 µm et une précision inférieure à 1% en terme de transparence malgré un éclairage peu homogène. La quantification des CGHs de type Fresnel et Fourier ont été calculés, réalisés et testés avec succès. Deux nouveaux algorithmes de Fourier ont étaient imaginés, réalisés et ont montrés des performances très supérieurs au code usuel de Lee qui est un codage binaire. / Micro-opto-electro-mecanical systems (MOEMS) are primordial tools for future applications in several scientific fields as telecommunications or image display. Astronomy takes also advantage of their great adaptatbility thanks to the development of adaptative optics; a new spectro-imager called BATMAN has recently been develloped to be installed at Telescopio Nazionale Galileo (TNG) in the Canaries Islands. The control of the MOEMS allowing computerizing this processus has been the starting point of my work at the LAM.The main part of this manuscript deals with another application conceived thanks to the association of the characteristics of MOEMS and photosensitive materials developed at Politecnico di Milano (Italy). These materials can be put in two states differentiated by their transparency. The MOEMS, initially used to display images, allows controlling the dose of light projected on the photocrhomic plate which reacts by becoming more and more transparent. This process permit to record Computer Generated Holograms (CGHs) in grayscale which are used in optical metrology. Today, binary CGHs are used but our process allows to record amplitude quantified CGHs with a resolution of 13.68 µm and a precision better than 1% in term of transparency, even with a non homogeneous illumination beam. Comparative studies have shown advantages of quantified CGHs of Fresnel and Fourier families. Two new Fourier algorithms have been conceived thanks to use of the third dimension offered by the control of the transparency. They have been realized and tested succesfully, and have shown much better performances than the current binary coding, so called Lee algorithm.

Avec la tendance continue vers la technologie nanométrique et l'augmentation des fonctions complexes intègres dans les électroniques systèmes embarqués, Assurant la compatibilité électromagnétique (CEM) des systèmes électroniques est un grand défi. CEM est devenu une cause majeure de redesign des Circuits intègres (CI). D’ailleurs, les performances des circuits pourraient être affectés par les mécanismes de dégradation tels que hot carrier injection (HCI), negative bias temperature instability (NBTI), gate oxide breakdown, qui sont accélérés par les conditions d'exploitation extrême (haute / basse température, surcharge électrique, le rayonnement). Ce vieillissement naturel peut donc affecter les performances CEM des circuits intégrés.Les travaux développés dans notre laboratoire vise à clarifier le lien entre les dégradations induites par le vieillissement et les dérives CEM, de développer les modèles de prédiction et de proposer des "insensibles au cours du temps" structures pour CEM protection, afin de fournir des méthodes et des guidelines aux concepteurs d'équipements et CI pour garantir la CEM au cours de durée de vie de leurs applications. Ce sujet de recherche est encore sous-exploré en tant que communautés de recherche sur la «fiabilité IC» et «compatibilité électromagnétique IC» n’a souvent pas de chevauchement.Ce manuscrit de thèse introduit une méthode pour quantifier l'effet du vieillissement sur les CEM des circuits intégrés par la mesure et la simulation. Le premier chapitre donne un aperçu du contexte général et le deuxième chapitre est dédié a l’état de l'art de CEM des circuits intégrés et de problèmes de fiabilité IC. Les résultats expérimentaux de circuits CEM évolution sont présentés dans le troisième chapitre. Ensuite, le quatrième chapitre est consacré à la caractérisation et la modélisation des mécanismes de dégradation du CI. Un EMR modèle qui inclut l'élément le vieillissement pour prédire la dérive du niveau CEM de notre puce de test après stress est proposé / With the continuous trend towards nanoscale technology and increased integration of complex electronic functions in embedded systems, ensuring the electromagnetic compatibility (EMC) of electronic systems is a great challenge. EMC has become a major cause of IC redesign. Meanwhile, ICs performance could be affected by the degradation mechanisms such as hot carrier injection (HCI), negative bias temperature instability(NBTI), gate oxide breakdown, which are accelerated by the harsh operation conditions (high/low temperature, electrical overstress, radiation). This natural aging can thus affect EMC performances of ICs. The work developed in our laboratory aims at clarifying the link between ageing induced IC degradations and related EMC drifts, developing prediction models and proposing “time insensitive” EMC protection structures, in order to provide methods and guidelines to IC and equipment designers to ensure EMC during lifetime of their applications. This research topic is still under-explored as research communities on “IC reliability” and “IC electromagnetic compatibility” has often no overlap. The PhD manuscript introduced a methodology to quantify the effect of ageing on EMC of ICs by measurement and simulation. The first chapter gives an overview of the general context and the second chapter states the EMC of ICs state of the art and IC reliability issues. The experimental results of ICs EMC evolution are presented in the third chapter. Then, the fourth chapter is dedicated to the characterization and modeling IC degradation mechanism. An EMR model which includes the ageing element to predict our test chip’s EMC level drift after stress is proposed

Les dispositifs DBD se répandent dans un grand nombre d’applications industrielles. Utilisés depuis plus de 150 ans pour la production d’ozone afin de décontaminer l’eau à grande échelle, ils ont depuis la fin du XXème siècle investi les domaines du traitement de surface polymère, du dépôt de couche mince sur substrat et de l’émission lumineuse pour la décontamination ainsi que la médecine. Ces dispositifs sont mis en oeuvre avec un générateur électrique dont les caractéristiques impactent fortement la qualité de la décharge. Ce travail s’inscrit en partie dans le cadre du développement d’une application de traitement de surface à pression atmosphérique. Il aborde la problématique de l’augmentation de la vitesse de dépôt de couche mince au travers des paramètres de l’alimentation électrique. Plus précisément, ce travail s’intéresse aux apports d’une alimentation en courant rectangulaire et aborde également les problématiques liées à la conception et à la fabrication de ce convertisseur. En particulier, une grande attention est portée sur l’étude du transformateur élévateur, car au travers de ses éléments parasites capacitifs, ce dernier peut limiter le transfert de puissance entre la source électrique et le dispositif DBD. Un deuxième aspect de cette étude consiste à entrevoir l’intérêt que revêtent deux convertisseurs statiques dédiés à l’alimentation de dispositifs DBD. Le premier consiste en une alimentation résonante en régime de conduction discontinue dont la particularité est de posséder trois degrés de liberté (fréquence, tension d’entrée et largeur d’impulsion), ce qui lui confère un intérêt exploratoire. Le second convertisseur consiste en une alimentation résonante haute tension et haute fréquence permettant l’éviction du transformateur élévateur, et mettant en oeuvre des interrupteurs au nitrure de gallium (GaN) afin d’atteindre une fréquence de fonctionnement supérieure au mega-Hertz avec un faible niveau de pertes. / DBD devices are widely used in industrial applications. 150 years ago, they were only employed in ozoners for water decontamination. In recent decades, the progress of knowledge and technology allowed to use them in many other applications like surface treatment, medical applications and light emission. Actually, these devices are supplied with an electrical source which parameters can strongly impact the discharge behaviour. An important part of this work comes within the framework of the development of an atmospheric pressure surface treatment involving DBDs. The issue of the influence of the generator's electrical parameters on the treatment speed is discussed. In particular, this work focuses on the merits of a rectangular shaped current source concerning the behavior of an atmospheric pressure discharge in nitrogen ; the problems related to the design and the fabrication of such a converter are highlighted. The design of the high voltage transformer is then described in detail since its lumped elements play an important role as they can strongly limit the power transfer between the electrical source and the DBD device. A second aspect of this work is to establish the interests of two particular power converters. The first one is a resonant converter operating in a discontinuous conduction mode ; its merits is to exhibit three degrees of freedom (input voltage, frequency, current pulse width) instead of two, which is a tremendous asset for exploring purposes. The second one is a high-frequency resonant converter where a resonant inductance and the DBD device structural capacitances are used instead of a high voltage transformer to perform the voltage amplification, which circumvents the issue related to the transformer parasitic elements. This converter is based on GaN HEMT switches in order to reach a low semiconductor losses level and a fairly high operating frequency (above the mega-Hertz).

A atividade de mudança do uso da terra na Amazônia vem sendo apontada como principal fonte de CO2 para a atmosfera em função das emissões de C e N provenientes do solo. A prática de manejo adotada pode influenciar significativamente nos estoques de C e N do solo funcionando como dreno ou fonte de C e N para a atmosfera. Além disso, podem ser alterados: a fertilidade e a densidade do solo bem como as frações e a origem da MOS. Com o objetivo de avaliar o impacto das mudanças de uso da terra na região leste da Amazônia foram coletadas amostras de terra nos principais usos da terra na região de Santarém-PA, em três profundidades: 0-10, 10-20 e 20-30 cm. Através das amostras foi realizada a caracterização físico-química das áreas e foram determinados os teores de C e N do solo e os isótopos ? 13C e ? 15N com a finalidade de quantificar os estoques de C e N do solo e avaliar a dinâmica e origem da MOS. Para um subconjunto de amostras foi realizado o fracionamento físico da MOS e a determinação do C da biomassa microbiana para compreender como a mudança de uso da terra interferiu nessas frações. Somado a essas determinações foi realizada a estimativa dos fatores de emissão com base na metodologia descrita pelo IPCC. Através da caracterização físicoquímica as áreas de estudo são caracterizadas por solos argilosos a muito argilosos. Os maiores valores de pH, macronutrientes, CTC, SB e V% foram observados nas áreas de agricultura (AGR) sugerindo que a utilização de práticas como adubação e calagem, são capazes de alterar os padrões de fertilidade do solo na Amazônia, aumentando seus índices de fertilidade. Para os estoques de C e N pode-se dizer que a mudança de uso da terra na região estudada está contribuindo para as perdas de C e N do solo, principalmente quando a conversão é realizada para áreas de agricultura (AGR) e pastagem (PA) sendo que os estoques de C observados na camada de 0-30 cm nessas áreas foram 49,21 Mg C ha-1 (PA) e 48,60 Mg C ha-1 (AGR). O maior valor de ? 13C foi encontrado nas áreas de pastagens, -25,08?, sugerindo que para as áreas de PA existe diluição isotópica e que parte do C do solo ainda é remanescente da floresta. As frações da MOS apresentaram alterações na quantidade de C e na proporção das frações leve e oclusa, principalmente nos usos AGR e PA. A fração lábil da MOS (C da biomassa microbiana) também apresentou grande diferença entre os usos FLO e AGR (526,21 e 296,78 ?g g-1de solo seco), indicando que a AGR foi o uso que mais alterou os estoques de C e N do solo e também as frações da MOS. Os fatores de emissão calculados confirmam todos os resultados observados em relação a conversão de FLO para AGR, sendo que para esse uso o fator de emissão foi de 0,93 ± 0,033, sendo então o uso que mais emitiu C. Com base nos resultados conclui-se que a introdução de áreas agrícolas na região de Santarém, é a principal causa de perda de C e N do solo e consequentemente é o uso que mais contribui com as emissões de gases do efeito estufa. / The land use change in the Brazilian Amazon has been identified as the main source of CO2 to the atmosphere due to emissions of soil carbon and nitrogenl. The management practice adopted can strongly influence the soil C and N stocks and may works like a sink or source of C and N to the atmosphere. Furthermore, can be changed: the soil fertility and bulk density as well as the SOM fractions and C source of the SOM. With the objective of evaluate the impact of the land use change in eastern Amazonia soil samples were collected in the main land uses in Santarém region, Para State of Brazil, at three depths: 0-10, 10-20 and 20-30 cm. Through the samples was performed the physicochemical characterization of the areas and were determined the soil C and N contents as well the isotopes ? 13C and ? 15N in order to quantify the soil C and N stocks and understand the SOM dynamics and evaluate the SOM origin. For a subset of samples were performed the physical fractionation of SOM and the determination of microbial biomass C to understand how the land use change may interfere in these fractions. Added to these determinations were estimated the emission factors based on the methodology described by the IPCC. Through the physicochemical characterization study areas can be characterized as a clayey loamy soils. The highest values of pH, macronutrients, CEC , sum of bases and base saturation were observed in croplands (CP), suggesting that the use of practices such as fertilization and liming are able to change the soil fertility patterns in the Amazon, increasing their fertility. For C and N stocks can be said that the land use change in the study area is contributing to the loss of soil C and N, especially when the conversion is done for croplands (CP) and grasslands (GS) areas and the value observed for soil C stocks in the 0-30 cm layer in these areas were 49.21 Mg C ha-1 (GS) and 48.60 Mg C ha-1 (CP). The highest ? 13C value was found in GS, -25.08 ?, suggesting that for these areas is occurring an isotope dilution and that part of the soil C is still remaining from forest. The SOM fractions showed changes in the amount of C and in the proportion of light and occluded fractions, especially in the uses CP and GS. The labile SOM fractions (microbial biomass) also showed a large difference between the UF and CP uses (526.21 and 296.78 mg g-1 of dry soil), indicating that CP affects the soil C and N stocks and also the SOM fractions. The emission factors calculated confirm all results observed for the conversion of UF for CP, and for this use the emission factor was 0.93 ± 0.033, and then this was the use that emitted more C. Based on the results we conclude that the introduction of croplands in Santarem region is the main cause of soil C and N loss and consequently contributes more to the greenhouse gases emission.

The thesis deals with a concept of turning a conventional petrol powered lawn mower to a battery powered solution which is powered by lithium cells. A division to three chapters, comparison, mechanical and electrical, provides fluency of the whole design and further realization. The arrangement of chapters is performed so that the continuity of the thesis is maintained. Calculations of parameters of every motor and transmission with choosing particular devices are just a part of much interesting information which can be found in this thesis. All new components have full documentation except those which were changed during manufacturing. The electrical part explains every part of the schematics in detail. The realization contains difference between preliminary design and further production, manufacturing of the PCB and powering up the motor drives. The last part of the thesis contains temperature measurements of the device at no load.

Die vorliegende Arbeit beschreibt die Berechnung und Optimierung von Silicon-On-Insulator-Metal-Oxide-Semiconductor-Field-Effect-Transistors, einschließlich noch nicht in Massenproduktion hergestellter neuartiger Transistorarchitekturen für die nächsten Technologiegenerationen der hochleistungsfähigen Logik-MOSFETs mit Hilfe der Prozess- und Bauelementesimulation. Die neuartigen Transistorarchitekturen umfassen dabei vollständig verarmte SOI-MOSFETs, Doppel-Gate-Transistoren und FinFETs. Die statische und dynamische Leistungsfähigkeit der neuartigen Transistoren wird durch Simulation bestimmt und miteinander verglichen. Der mit weiterer Skalierung steigende Einfluss von statistischen Variationen wird anhand der Oberflächenrauheit sowie der Polykantenrauheit untersucht. Zu diesem Zweck wurden Modelle für die Generierung der Rauheit erarbeitet und in das Programmsystem SIMBA implementiert. Die mikroskopische Rauheit wird mit der makroskopischen Bauelementesimulation kombiniert und deren Auswirkungen auf die Standardtransistoren und skalierte Bauelemente aufgezeigt. Zudem erfolgt eine ausführliche Diskussion der Modellierung mechanischer Verspannung und deren Anwendung zur Steigerung der Leistungsfähigkeit von MOSFETs. Die in SIMBA implementierten Modelle zur verspannungs-abhängigen Änderung der Ladungsträgerbeweglichkeit und Lage der Bandkanten werden ausführlich dargestellt und deren Einfluss auf die elektrischen Parameter von MOSFETs untersucht. Weiterhin wird die Verspannungsverteilung für verschiedene Herstellungsvarianten mittels der Prozess-simulation berechnet und die Wirkung auf die elektrischen Parameter dargestellt. Exponential- und Gaußverteilungsfunktionen bilden die Grundlage, um die mechanische Verspannung in der Bauelementesimulation nachzubilden, ohne die Verspannungsprofile aus der Prozesssimulation zu übernehmen. Darüber hinaus werden die Grenzfrequenzen der Logiktransistoren in Bezug auf die parasitären Kapazitäten und Widerstände und zur erweiterten MOSFET-Charakterisierung dargestellt.

The impact of acculturation and poor social support as potential risk factors for cardiovascular and metabolic disease amongst Mexican immigrants to the United States (U.S.) is a developing area of research. One theory is that acculturation to U.S. society is negatively associated with health due to the stress of immigration as well as the less healthy diet and lifestyle in the U.S. It is also theorized that positive social support is associated with better health during immigration due to the buffering effect relationships have on stress. Despite these theories, mixed findings have been found regarding the associations between acculturation and social support to health outcomes in this population. Some research has also noted that significant differences exist between the manner in which men and women experience social support and their acculturation patterns. Consequently, the primary purpose of this study was to test the associations between acculturation and health as well as assess gender, social support, and acculturation for potential moderator effects in a sample of Mexican immigrants in Provo, Utah. Acculturation was measured using the Acculturation Rating Scale for Mexican Americans-II (ARMSA-II) which consists of the Anglo Orientation Scale (AOS) and Mexican Orientation Scale (MOS). Social support was determined using both the Interpersonal Support Evaluation List (ISEL) and Sarason Social Support Questionnaire (SSSQ) which has two dimensions: satisfaction with support network and size of support network. Hierarchical multiple regression did not find significant associations between acculturation or social support and health outcomes as measured by ambulatory blood pressure or blood draw values including triglycerides, Hemoglobin A1c (HbA1c), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). A significant association was observed between Anglo Orientation and social support as measured by the ISEL-II. A moderation effect was observed between gender and Anglo orientation with satisfaction in one's support network. No other moderation effects were observed in this study. Implications of the findings, limitations, and directions for future research are discussed.

NASA missions require innovative power electronics system and component solutions with long life capability, high radiation tolerance, low mass and volume, and high reliability in space environments. Presently vertical double-diffused MOSFETs (VDMOS) are the most widely used power switching device for space power systems. It is proposed that a new lateral double-diffused MOSFET (LDMOS) designed at UCF can offer improvements in total dose and single event radiation hardness, switching performance, development and manufacturing costs, and total mass of power electronics systems. Availability of a hardened fast-switching power MOSFET will allow space-borne power electronics to approach the current level of terrestrial technology, thereby facilitating the use of more modern digital electronic systems in space. It is believed that the use of a p+/p-epi starting material for the LDMOS will offer better hardness against single-event burnout (SEB) and single-event gate rupture (SEGR) when compared to vertical devices fabricated on an n+/n-epi material. By placing a source contact on the bottom-side of the p+ substrate, much of the hole current generated by a heavy ion strike will flow away from the dielectric gate, thereby reducing electrical stress on the gate and decreasing the likelihood of SEGR. Similarly, the device is hardened against SEB by the redirection of hole current away from the base of the device's parasitic bipolar transistor. Total dose hardness is achieved by the use of a standard complementary metal-oxide semiconductor (CMOS) process that has shown proven hardness against total dose radiation effects.

Many modern digital systems use forms of CMOS logical implementation due to the straight forward design nature of CMOS logic and minimal device area since CMOS uses fewer transistors than other logic families. To achieve high-performance requirements in mixed-signal chip development and quiet, noiseless circuitry, this thesis provides an alternative toCMOSin the form of MOS Current Mode Logic (MCML). MCML dissipates constant current and does not produce noise during value changing in a circuit CMOS circuits do. CMOS logical networks switch during clock ticks and with every device switching, noise is created on the supply and ground to deal with the transitions. Creating a noiseless standard cell library with MCML allows use of circuitry that uses low voltage switching with 1.5V between logic levels in a quiet or mixed-signal environment as opposed to the full rail to rail swinging of CMOS logic. This allows cohesive implementation with analog circuitry on the same chip due to constant current and lower switching ranges not creating rail noise during digital switching. Standard cells allow for the Cadence tools to automatically generate circuits and Cadence serves as the development platform for the MCML standard cells. The theory surrounding MCML is examined along with current and future applications well-suited for MCML are researched and explored with the goal of highlighting valid candidate circuits for MCML. Inverters and NAND gates with varying current drives are developed to meet these specialized goals and are simulated to prove viability for quiet, mixed-signal applications. Analysis and results show that MCML is a superior implementation choice compared toCMOSfor high speed and mixed signal applications due to frequency independent power dissipation and lack of generated noise during operation. Noise results show rail current deviations of 50nA to 300nA during switching over an average operating current of 20µA to 80µA respectively. The multiple order of magnitude difference between noise and signal allow the MCML cells to dissipate constant power and thus perform with no noise added to a system. Additional simulated results of a 31-stage ring oscillator result in a frequency for MCML of 1.57GHz simulated versus the 150.35MHz that MOSIS tested on a fabricated 31-stage CMOS oscillator. The layouts designed for the standard cell library conform to existing On Semiconductor ami06 technology dimensions and allow for design of any logical function to be fabricated. The I/O signals of each cell operate at the same input and output voltage swings which allow seamless integration with each other for implementation in any logical configuration.