Les systèmes mobiles intelligents sont déjà dotés de plusieurs composants de type capteur comme les accéléromètres, les thermomètres et les détecteurs infrarouge. Cependant, jusqu’à aujourd’hui l’intégration de capteurs chimiques dans des systèmes compacts sur puce reste limitée pour des raisons de consommation d’énergie et dissipation de chaleur principalement. Le travail présenté dans cette thèse fut donc concentrée sur la démonstration de l’intégration 3D monolithique de SETs sur un substrat de technologie CMOS (Complementary Metal Oxide Semiconductor) pour la réalisation de la fonction capteurs de gaz très sensible et ultra basse consommation d’énergie. L’approche proposée consiste à l’intégration de SETs métalliques à double grilles dans l'unité de fabrication finale BEOL (Back-End-Of-Line) d'une technologie CMOS à l’aide du procédé nanodamascene. L'objectif principal de cette thèse de doctorat peut être divisé en 4 parties : (1) la modélisation et simulation de la réponse d’capteur de gaz à base de SET à double grilles ou d’un MOSFET FD-SOI, et l’estimation de la sensitivité ainsi que la puissance consommée; (2) la caractérisation de la sensitivité du Pt comme couche sensible pour la détection du H2 par la technique de mesure de charge de surface, et le développement du procédé de texturation de surface de la grille fonctionnalisée avec les réseaux de nanotubes de carbone; (3) le développement et l’optimisation du procédé de fabrication des SETs à double grilles dans l’entité BEOL d’un substrat CMOS; et (4) la fonctionnalisation d’un MOSFET FD-SOI avec du Pt pour réalise la fonction de capteur de H2. / The need of integration of new functionalities on mobile and autonomous electronic systems has to take into account all the problematic of heterogeneity together with energy consumption and thermal power dissipation. Therefore, the work presented in this thesis is focussed on the proof of concept of 3D monolithical integration of SETs on CMOS technology for high sensitivity and ultra-low power gas sensing functionality. The proposed approach is to integrate metallic double gate-single electron transistors (DG-SETs) in the Back-End-Of-Line (BEOL) of CMOS circuits (within the CMOS interconnect layers) using the nanodamascene process. The main objective of this Ph.D. thesis can be divided into 4 parts: (1) modelling and simulation of a DG-SET and an FD-SOI MOSFET based gas sensor response, and estimation of the sensitivity as well as the power consumption; (2) investigation of Pt sensitivity to hydrogen by surface charge measurement technique and development of the sensing electrode surface texturing process with CNT networks; (3) development and optimization of DG-SET integration process in the BEOL of a CMOS substrate, and (4) FD-SOI MOSFET functionalization with Pt for H2 sensing.

La forte demande et le besoin d’intégration hétérogène de nouvelles fonctionnalités dans les systèmes mobiles et autonomes, tels que les mémoires, capteurs, et interfaces de communication doit prendre en compte les problématiques d’hétérogénéité, de consommation d’énergie et de dissipation de chaleur. Les systèmes mobiles intelligents sont déjà dotés de plusieurs composants de type capteur comme les accéléromètres, les thermomètres et les détecteurs infrarouge. Cependant, jusqu’à aujourd’hui l’intégration de capteurs chimiques dans des systèmes compacts sur puce reste limitée pour des raisons de consommation d’énergie et dissipation de chaleur principalement. La technologie actuelle et fiable des capteurs de gaz, les résistors à base d’oxyde métallique et les MOSFETs (Metal Oxide Semiconductor- Field Effect Transistors) catalytiques sont opérés à de hautes températures de 200–500 °C et 140–200 °C, respectivement. Les transistors à effet de champ à grille suspendu (SG-FETs pour Suspended Gate-Field Effect Transistors) offrent l’avantage d’être sensibles aux molécules gazeuses adsorbées aussi bien par chemisorption que par physisorption, et sont opérés à température ambiante ou légèrement au-dessus. Cependant l’intégration de ce type de composant est problématique due au besoin d’implémenter une grille suspendue et l’élargissement de la largeur du canal pour compenser la détérioration de la transconductance due à la faible capacité à travers le gap d’air. Les transistors à double grilles sont d’un grand intérêt pour les applications de détection de gaz, car une des deux grilles est fonctionnalisée et permet de coupler capacitivement au canal les charges induites par l’adsorption des molécules gazeuses cibles, et l’autre grille est utilisée pour le contrôle du point d’opération du transistor sans avoir besoin d’une structure suspendue. Les transistors monoélectroniques (les SETs pour Single Electron Transistors) présentent une solution très prometteuse grâce à leur faible puissance liée à leur principe de fonctionnement basé sur le transport d’un nombre réduit d’électrons et leur faible niveau de courant. Le travail présenté dans cette thèse fut donc concentré sur la démonstration de l’intégration 3D monolithique de SETs sur un substrat de technologie CMOS (Complementary Metal Oxide Semiconductor) pour la réalisation de la fonction capteurs de gaz très sensible et ultra basse consommation d’énergie. L’approche proposée consiste à l’intégration de SETs métalliques à double grilles dans l’unité de fabrication finale BEOL (Back-End-Of-Line) d’une technologie CMOS à l’aide du procédé nanodamascene. Le système sur puce profitera de la très élevée sensibilité à la charge électrique du transistor monoélectronique, ainsi que le traitement de signal et des données à haute vitesse en utilisant une technologie de pointe CMOS disponible. Les MOSFETs issus de la technologie FD-SOI (Fully Depleted-Silicon On Insulator) sont une solution très attractive à cause de leur pouvoir d’amplification du signal quand ils sont opérés dans le régime sous-le-seuil. Ces dispositifs permettent une très haute densité d’intégration due à leurs dimensions nanométriques et sont une technologie bien mature et modélisée. Ce travail se concentre sur le développement d’un procédé de fonctionnalisation d’un MOSFET FD-SOI comme démonstration du concept du capteur de gaz à base de transistor à double grilles. La sonde Kelvin a été la technique privilégiée pour la caractérisation des matériaux sensibles par le biais de mesure de la variation du travail de sortie induite par l’adsorption de molécules de gaz. Dans ce travail, une technique de caractérisation des matériaux sensibles alternative basée sur la mesure de la charge de surface est discutée. Pour augmenter la surface spécifique de l’électrode sensible, un nouveau concept de texturation de surface est présenté. Le procédé est basé sur le dépôt de réseaux de nanotubes de carbone multi-parois par pulvérisation d’une suspension de ces nanotubes. Les réseaux déposés servent de «squelettes» pour le matériau sensible. L’objectif principal de cette thèse de doctorat peut être divisé en 4 parties : (1) la modélisation et simulation de la réponse d’un capteur de gaz à base de SET à double grilles ou d’un MOSFET FD-SOI, et l’estimation de la sensibilité ainsi que la puissance consommée; (2) la caractérisation de la sensibilité du Pt comme couche sensible pour la détection du H[indice inférieur 2] par la technique de mesure de charge de surface, et le développement du procédé de texturation de surface de la grille fonctionnalisée avec les réseaux de nanotubes de carbone; (3) le développement et l’optimisation du procédé de fabrication des SETs à double grilles dans l’entité BEOL d’un substrat CMOS; et (4) la fonctionnalisation d’un MOSFET FD-SOI avec du Pt pour réaliser la fonction de capteur de H[indice inférieur 2]. / Abstract : The need of integration of new functionalities on mobile and autonomous electronic systems has to take into account all the problematic of heterogeneity together with energy consumption and thermal dissipation. In this context, all the sensing or memory components added to the CMOS (Complementary Metal Oxide Semiconductor) processing units have to respect drastic supply energy requirements. Smart mobile systems already incorporate a large number of embedded sensing components such as accelerometers, temperature sensors and infrared detectors. However, up to now, chemical sensors have not been fully integrated in compact systems on chips. Integration of gas sensors is limited since most used and reliable gas sensors, semiconducting metal oxide resistors and catalytic metal oxide semiconductor- field effect transistors (MOSFETs), are generally operated at high temperatures, 200–500 °C and 140–200° C, respectively. The suspended gate-field effect transistor (SG-FET)-based gas sensors offer advantages of detecting chemisorbed, as well as physisorbed gas molecules and to operate at room temperature or slightly above it. However they present integration limitations due to the implementation of a suspended gate electrode and augmented channel width in order to overcome poor transconductance due to the very low capacitance across the airgap. Double gate-transistors are of great interest for FET-based gas sensing since one functionalized gate would be dedicated for capacitively coupling of gas induced charges and the other one is used to bias the transistor, without need of airgap structure. This work discusses the integration of double gate-transistors with CMOS devices for highly sensitive and ultra-low power gas sensing applications. The use of single electron transistors (SETs) is of great interest for gas sensing applications because of their key properties, which are its ultra-high charge sensitivity and the ultra-low power consumption and dissipation, inherent to the fundamental of their operation based on the transport of a reduced number of charges. Therefore, the work presented in this thesis is focused on the proof of concept of 3D monolithic integration of SETs on CMOS technology for high sensitivity and ultra-low power gas sensing functionality. The proposed approach is to integrate metallic double gate-single electron transistors (DG-SETs) in the Back-End-Of-Line (BEOL) of CMOS circuits (within the CMOS interconnect layers) using the nanodamascene process. We take advantage of the hyper sensitivity of the SET to electric charges as well from CMOS circuits for high-speed signal processing. Fully depleted-silicon on insulator (FD-SOI) MOSFETs are very attractive devices for gas sensing due to their amplification capability when operated in the sub-threshold regime which is the strongest asset of these devices with respect to the FET-based gas sensor technology. In addition these devices are of a high interest in terms of integration density due to their small size. Moreover FD-SOI FETs is a mature and well-modelled technology. We focus on the functionalization of the front gate of a FD-SOI MOSFET as a demonstration of the DGtransistor- based gas sensor. Kelvin probe has been the privileged technique for the investigation of FET-based gas sensors’ sensitive material via measuring the work function variation induced by gas species adsorption. In this work an alternative technique to investigate gas sensitivity of materials suitable for implementation in DG-FET-based gas sensors, based on measurement of the surface charge induced by gas species adsorption is discussed. In order to increase the specific surface of the sensing electrode, a novel concept of functionalized gate surface texturing suitable for FET-based gas sensors are presented. It is based on the spray coating of a multi-walled-carbon nanotubes (MW-CNTs) suspension to deposit a MW-CNT porous network as a conducting frame for the sensing material. The main objective of this Ph.D. thesis can be divided into 4 parts: (1) modelling and simulation of a DG-SET and a FD-SOI MOSFET-based gas sensor response, and estimation of the sensitivity as well as the power consumption; (2) investigation of Pt sensitivity to hydrogen by surface charge measurement technique and development of the sensing electrode surface texturing process with CNT networks; (3) development and optimization of the DG-SET integration process in the BEOL of a CMOS substrate, and (4) FD-SOI MOSFET functionalization with Pt for H[subscript 2] sensing.

Encontrar soluções para a problemática dos resíduos e, em virtude da crescente demanda por energia, diminuir a dependência dos combustíveis fósseis têm constituído grandes desafios para os pesquisadores. O setor hospitalar é um potencial gerador dos chamados Resíduos de Serviços de Saúde (RSS) que também apresenta um alto consumo de energia em decorrência do seu período de funcionamento e de equipamentos que necessitam de infraestrutura adequada. Apesar de representarem uma pequena parcela perante o montante dos Resíduos Sólidos Urbanos (RSU), no Brasil, nem todos os geradores se preocupam com seu tratamento e destinação final. O emprego de tecnologias desenvolvidas para o tratamento desses resíduos com a possibilidade de recuperação energética deve ser avaliado. O Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HC-FMRP-USP) gera cerca de 1,9 ton/dia de RSS. Nesse contexto, o objetivo geral desta pesquisa foi avaliar a viabilidade legal, ambiental e econômico-financeira da implantação de um sistema próprio de tratamento de RSS no HCFMRP- USP para geração de energia. A metodologia foi estruturada em pesquisa exploratória, coleta de dados por meio de entrevistas semi-estruturadas com responsáveis pelo setor dos RSS no hospital, com pesquisadores da área da saúde, de escolas de engenharia, órgãos técnicos e indústrias fabricantes dos equipamentos; levantamento bibliográfico e análise de conteúdo. Para a avaliação econômico-financeira, foi empregada a avaliação custoefetividade. Estudos comparativos sobre os tipos de tratamento disponíveis e utilizados nacionalmente foram considerados. Assim, o processo que melhor se adequou ao sistema proposto foi o da incineração com tecnologia de gaseificação e combustão combinadas (GCC). Os resultados demonstraram que o sistema proposto está sob a égide da lei contemplando, inclusive, a Política Nacional de Resíduos Sólidos (PNRS), desde que mediante anuência do Conselho Gestor do campus da USP e de sua Comissão de Meio Ambiente, além do devido processo de licenciamento ambiental junto à CETESB e pré-análise dos RSS. Contudo, sob o aspecto ambiental há questões públicas e políticas sobre a aceitação de sua implantação no complexo hospitalar. Embora haja o emprego de avançada tecnologia, o equipamento avaliado necessita de instalação, manutenção e monitoramento adequados por profissionais capacitados para operá-los, a fim de se evitar possíveis danos às pessoas e ao meio-ambiente, para isso, os envolvidos devem agir com responsabilidade. Por fim, sob o aspecto econômico-financeiro houve um empate técnico entre os custos do tratamento realizado atualmente e os da proposta do investimento. Assim, esse último aspecto avaliado incidiu sobre o benefício implícito da decisão de se implantar ou não o processo. Portanto, considera-se a viabilidade da implantação de um sistema próprio para tratamento de RSS no HCFMRP-USP para geração de energia sob os três aspectos: legal, ambiental e econômicofinanceiro. / Finding solutions to the waste problem and reducing dependence on fossil fuels due to the growing demand for energy have become big challenges for researchers to deal with. Hospitals are large producers of Medical waste (MW) and also big energy consumers due to their long running hours and the running of equipment that demands adequate infrastructure. Despite accounting for a small share of all the Municipal Solid Waste (MSW) not all producers, in Brazil, are concerned about waste treatment and its final destination. The use of technologies developed with the aim of treating such waste in order to generate energy has to be assessed. The Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP) generates around 1.9 tons of waste per day. In this context, the general aim of this research program was to assess the legal, environmental and economic-financial feasibility of the implementation of a private system of biomedical waste treatment at HCFMRP-USP in order to generate energy. The method was structured in exploratory research, data gathering by means of semi-structured interviews with MW department staff at the hospital, with Health researchers, with Engineering College researchers, technical organizations and equipment manufacturers, besides bibliographic referencing and content analysis. Cost-effectiveness analysis was used for the economic-financial analysis. Comparative studies of the types of treatment available and used nationwide were taken into consideration. Thus, the process which best suited the proposed system was that of incineration by means of Gasification Combined Cycle (GCC). Results showed that the proposed system is under the support of Law and it also takes into consideration the National Policy for Solid Waste (NPSW), provided that it has the approval of the Director Council of the Administration of the campus of USP and of its Environment Committee as well as appropriate environmental licenses granted by CETESB and pre-analysis of MW. However, under the environmental aspect, there are public and political issues regarding the acceptance of this implementation in the hospital premises. Although there is the use of advanced technology, the equipment which was assessed needs to be installed, maintained and monitored adequately by professionals trained to operate it so as to avoid possible damage to humans and the environment. Staff involved must be responsible. Finally, under the economic-financial aspect there was a draw between the costs of the treatment conducted at present and those of the proposed investment. Therefore, this last aspect assessed prevailed over the implicit benefit of the decision on whether to implement the process or not. However, the feasibility of the implementation of a private MW treatment system at HC-FMRP-USP in order to generate energy is to be considered under the legal, environmental and economicfinancial aspects.

Encontrar soluções para a problemática dos resíduos e, em virtude da crescente demanda por energia, diminuir a dependência dos combustíveis fósseis têm constituído grandes desafios para os pesquisadores. O setor hospitalar é um potencial gerador dos chamados Resíduos de Serviços de Saúde (RSS) que também apresenta um alto consumo de energia em decorrência do seu período de funcionamento e de equipamentos que necessitam de infraestrutura adequada. Apesar de representarem uma pequena parcela perante o montante dos Resíduos Sólidos Urbanos (RSU), no Brasil, nem todos os geradores se preocupam com seu tratamento e destinação final. O emprego de tecnologias desenvolvidas para o tratamento desses resíduos com a possibilidade de recuperação energética deve ser avaliado. O Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HC-FMRP-USP) gera cerca de 1,9 ton/dia de RSS. Nesse contexto, o objetivo geral desta pesquisa foi avaliar a viabilidade legal, ambiental e econômico-financeira da implantação de um sistema próprio de tratamento de RSS no HCFMRP- USP para geração de energia. A metodologia foi estruturada em pesquisa exploratória, coleta de dados por meio de entrevistas semi-estruturadas com responsáveis pelo setor dos RSS no hospital, com pesquisadores da área da saúde, de escolas de engenharia, órgãos técnicos e indústrias fabricantes dos equipamentos; levantamento bibliográfico e análise de conteúdo. Para a avaliação econômico-financeira, foi empregada a avaliação custoefetividade. Estudos comparativos sobre os tipos de tratamento disponíveis e utilizados nacionalmente foram considerados. Assim, o processo que melhor se adequou ao sistema proposto foi o da incineração com tecnologia de gaseificação e combustão combinadas (GCC). Os resultados demonstraram que o sistema proposto está sob a égide da lei contemplando, inclusive, a Política Nacional de Resíduos Sólidos (PNRS), desde que mediante anuência do Conselho Gestor do campus da USP e de sua Comissão de Meio Ambiente, além do devido processo de licenciamento ambiental junto à CETESB e pré-análise dos RSS. Contudo, sob o aspecto ambiental há questões públicas e políticas sobre a aceitação de sua implantação no complexo hospitalar. Embora haja o emprego de avançada tecnologia, o equipamento avaliado necessita de instalação, manutenção e monitoramento adequados por profissionais capacitados para operá-los, a fim de se evitar possíveis danos às pessoas e ao meio-ambiente, para isso, os envolvidos devem agir com responsabilidade. Por fim, sob o aspecto econômico-financeiro houve um empate técnico entre os custos do tratamento realizado atualmente e os da proposta do investimento. Assim, esse último aspecto avaliado incidiu sobre o benefício implícito da decisão de se implantar ou não o processo. Portanto, considera-se a viabilidade da implantação de um sistema próprio para tratamento de RSS no HCFMRP-USP para geração de energia sob os três aspectos: legal, ambiental e econômicofinanceiro. / Finding solutions to the waste problem and reducing dependence on fossil fuels due to the growing demand for energy have become big challenges for researchers to deal with. Hospitals are large producers of Medical waste (MW) and also big energy consumers due to their long running hours and the running of equipment that demands adequate infrastructure. Despite accounting for a small share of all the Municipal Solid Waste (MSW) not all producers, in Brazil, are concerned about waste treatment and its final destination. The use of technologies developed with the aim of treating such waste in order to generate energy has to be assessed. The Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP) generates around 1.9 tons of waste per day. In this context, the general aim of this research program was to assess the legal, environmental and economic-financial feasibility of the implementation of a private system of biomedical waste treatment at HCFMRP-USP in order to generate energy. The method was structured in exploratory research, data gathering by means of semi-structured interviews with MW department staff at the hospital, with Health researchers, with Engineering College researchers, technical organizations and equipment manufacturers, besides bibliographic referencing and content analysis. Cost-effectiveness analysis was used for the economic-financial analysis. Comparative studies of the types of treatment available and used nationwide were taken into consideration. Thus, the process which best suited the proposed system was that of incineration by means of Gasification Combined Cycle (GCC). Results showed that the proposed system is under the support of Law and it also takes into consideration the National Policy for Solid Waste (NPSW), provided that it has the approval of the Director Council of the Administration of the campus of USP and of its Environment Committee as well as appropriate environmental licenses granted by CETESB and pre-analysis of MW. However, under the environmental aspect, there are public and political issues regarding the acceptance of this implementation in the hospital premises. Although there is the use of advanced technology, the equipment which was assessed needs to be installed, maintained and monitored adequately by professionals trained to operate it so as to avoid possible damage to humans and the environment. Staff involved must be responsible. Finally, under the economic-financial aspect there was a draw between the costs of the treatment conducted at present and those of the proposed investment. Therefore, this last aspect assessed prevailed over the implicit benefit of the decision on whether to implement the process or not. However, the feasibility of the implementation of a private MW treatment system at HC-FMRP-USP in order to generate energy is to be considered under the legal, environmental and economicfinancial aspects.

Les Personnes à Mobilité Réduite (PMR) souffrent souvent de limitation au cours de la locomotion. Plusieurs outils sont à leurs dispositions pour les aider et les assister dans leur déplacement, plus particulièrement le Fauteuil Roulant Manuel (FRM) ou électrique. Ces travaux de thèse se focalisent sur les interactions entre le sujet et le FRM afin de déterminer des éléments prédictifs du déplacement à venir dans l’optique d’une aide à la locomotion. Comprendre l'Interaction Homme-FRM (IHF) est un enjeu actuel afin d'améliorer le déplacement et d’optimiser la performance ainsi que le confort, en minimisant la fatigue et les risques des blessures. Pour contribuer à mieux comprendre voire améliorer cette IHF, un ensemble d'études centrées sur une analyse biomécanique et électromyographique des éléments d'anticipation de l'Initiation du Déplacement en FRM (ID-FRM) a été réalisé au cours de ces travaux de thèse. Cet ensemble d’études porte sur i) les Activités Musculaires Anticipatoires (AMA) en position assise pour interroger la prédictibilité des mouvements au regard de ses paramètres préalables ; ii) l’évolution des patterns musculaires et des pressions sur l'assise lors de l'ID-FRM, pour interroger l’adaptabilité ou la spécificité des paramètres initiaux lors de différents déplacements en FRM chez des sujets valides. ; iii) l’évolutions des patterns musculaires et des pressions sur l'assise lors de l'ID-FRM chez des sujets blessés médullaires et ; iv) l’analyse multi-variée des paramètres de l'ID-FRM. Le SNC présente des capacités d'adaptabilité importantes au mouvement à venir en ajustant les commandes motrices aux conditions physiologiques globales du sujet. Cette adaptabilité a conduit à des pourcentages importants de prédiction et elle peut être enregistrée au travers d'éléments macroscopiques permettant d'envisager des systèmes d'aide au déplacement, notamment pour les PMR. / People with Disabled Mobility (PDM) often suffer from limitation during locomotion. Several tools are at their disposal to help and assist them in their displacement, specifically the electric or the Manual Wheelchair (MW). This thesis works focuses on the Human-MW-Interaction (H-MW-I) subject to determine elements predictors of forthcoming displacement with a view of aid to locomotion. Understanding (H-MW-I) is a current challenge to improve the displacement and optimize the performance as well as comfort, by minimizing fatigue and injury risk. In order to enhance understanding and even improving the (H-MW-I), a set of studies focusing on Biomechanics and electromyographic analysis of anticipation elements of the Manual Wheelchair Initiation Displacement (MW-ID) was performed during the thesis works. This set of studies focuses on i) Anticipatory Muscular Activities (AMA) in the sitting position to question the predictability of the movements in relation to its prior parameters; ii) evolution of muscular patterns and pressures on the seat when MW-ID to question the adaptability or specificity of the initial parameters during various displacements using MW in healthy subjects ; iii) evolution of muscular patterns and pressures on the seat when MW-ID in spinal cord injury subjects and; iv) multivariate analysis of the MW-ID parameters. The CNS presents an important capacity of adaptability to the forthcoming movement by adjusting motor commands to the global physiological condition of the subject. This adaptability has led to significant percentages prediction and it can be saved through macroscopic elements to envisage help systems to displacement for PDM.

This thesis is divided into four distinct chapters all linked by the topic of spray cooling. Chapter one gives a detailed categorization of future and current spray cooling applications, and reviews the major advantages and disadvantages that spray cooling has over other high heat flux cooling techniques. Chapter two outlines the developmental goals of spray cooling, which are to increase the output of a current system and to enable new technologies to be technically feasible. Furthermore, this chapter outlines in detail the impact that land, air, sea, and space environments have on the cooling system and what technologies could be enabled in each environment with the aid of spray cooling. In particular, the heat exchanger, condenser and radiator are analyzed in their corresponding environments. Chapter three presents an experimental investigation of a fluid management system for a large area multiple nozzle spray cooler. A fluid management or suction system was used to control the liquid film layer thickness needed for effective heat transfer. An array of sixteen pressure atomized spray nozzles along with an imbedded fluid suction system was constructed. Two surfaces were spray tested one being a clear grooved Plexiglas plate used for visualization and the other being a bottom heated grooved 4.5 x 4.5 cm2 copper plate used to determine the heat flux. The suction system utilized an array of thin copper tubes to extract excess liquid from the cooled surface. Pure water was ejected from two spray nozzle configurations at flow rates of 0.7 L/min to 1 L/min per nozzle. It was found that the fluid management system provided fluid removal efficiencies of 98% with a 4-nozzle array, and 90% with the full 16-nozzle array for the downward spraying orientation. The corresponding heat fluxes for the 16 nozzle configuration were found with and without the aid of the fluid management system. It was found that the fluid management system increased heat fluxes on the average of 30 W/cm2 at similar values of superheat. Unfortunately, the effectiveness of this array at removing heat at full levels of suction is approximately 50% & 40% of a single nozzle at respective 10[degrees]C & 15[degrees]C values of superheat. The heat transfer data more closely resembled convective pooling boiling. Thus, it was concluded that the poor heat transfer was due to flooding occurring which made the heat transfer mechanism mainly forced convective boiling and not spray cooling. Finally, Chapter four gives a detailed guide for the design and construction of a high heat flux heater for experimental uses where accurate measurements of surface temperatures and heat fluxes are extremely important. The heater designs presented allow for different testing applications; however, an emphasis is placed on heaters designed for use with spray cooling.

The forecasting of Eskom transmission electrical network demands is a complex task. The lack of historical data on some of the network components complicates this task even further. In this dissertation a model is suggested which will address all the requirements of the transmission system expansion engineers in terms of future loads and market trends. Suggestions are made with respect to ways of overcoming the lack of historical data, especially on the point loads, which is a key factor in modelling the electrical networks. A brief overview of the transmission electrical network layout is included to provide a better understanding of what is required from such a forecast. Lastly, some theory on multiple regression, neural networks and qualitative forecasting techniques is included, which will be of value for further model developments. / Computing / M. Sc. (Operations Research)

This thesis deals with the analysis of nano-structured layers deposited by high-frequency magnetron sputtering on the monocrystalline silicon surface. The content of the work focuses on the magnetron sputtering application as an alternative method for passivation and antireflection layers deposition of silicon solar cells. The procedure of pre-deposite silicon surface cleaning by plasma etching in the Ar/H2 gas mixture atmosphere is suggested. In the next step the silicon nitride and aluminum nitride layers with hydrogen content in Ar/N2/H2 gas mixture by magnetron sputtering are deposited. One part of the thesis describes an experimental pseudo-carbide films deposition from a silicon target in the atmosphere of acetylene (C2H2). An emphasis is placed on the research of sputtered layers properties and on the conditions on the silicon-layer interface with the help of the standard as well as special measurement methods. Sputtered layers structure is analyzed by modern X-ray spectroscopy (XPS) and by Fourier infrared spectroscopy (FTIR). Optical ellipsometry and spectrophotometry is used for the diagnostic of the layers optical properties depending upon the wavelength of incident light. A special method of determining the surface lay-out of the charge´s carrier life in the volume and on the surface of silicon is employed to investigate the passivating effects of the sputtered layers.

The forecasting of Eskom transmission electrical network demands is a complex task. The lack of historical data on some of the network components complicates this task even further. In this dissertation a model is suggested which will address all the requirements of the transmission system expansion engineers in terms of future loads and market trends. Suggestions are made with respect to ways of overcoming the lack of historical data, especially on the point loads, which is a key factor in modelling the electrical networks. A brief overview of the transmission electrical network layout is included to provide a better understanding of what is required from such a forecast. Lastly, some theory on multiple regression, neural networks and qualitative forecasting techniques is included, which will be of value for further model developments. / Computing / M. Sc. (Operations Research)

Cette thèse présente un modèle unique du MASG (Modèle d’Architecture du Smart Grid) en considérant l 'état de l’art des différentes directives de recherche du smart grid. Le système hybride de génération d'énergie active marine-hydrogène a été modélisé pour représenter la couche de composants du MASG. Le système intègre l'électrolyseur à membrane d’échange de proton (à l’échelle de méga watt) et les systèmes de piles à combustible en tant que composants principaux du bilan énergétique. La batterie LiFePO4 est utilisée pour couvrir la dynamique rapide de l'énergie électrique. En outre, la thèse analyse le système de gestion de l'énergie centralisé et décentralisé. Le système multi-agents représente le paradigme du système décentralisé. La plate-forme JADE est utilisée pour développer le système multi-agents, en raison de son domaine d'application général, de ses logiciels à licence libre, de son interface avec MATLAB et de sa calculabilité avec les standards de la Fondation des Agents Physiques Intelligentes. Le système de gestion d'énergie basé sur JADE équilibre l'énergie entre la génération (système de conversion d'énergie marine-courant) et la demande (profil de charge résidentielle) pendant les modes de fonctionnement autonome et connecté au réseau. Le modèle proposé du MASG peut être considéré comme une étude de cas pilote qui permet l'analyse détaillée et les applications des différentes directions de recherche du smart grid. / This thesis presents a unique model of the SGAM (Smart Grid Architecture Model) with considering the state of the art of the different research directions of the smart grid and. The hybrid marine-hydrogen active power generation system has been modeled to represent the component layer of the SGAM. The system integrates the MW scale PEM electrolyzer and fuel cell systems as the main energy balance components. The LiFePO4 battery is used to cover the fast dynamics of the electrical energy. Moreover, the thesis analyzes the centralized and the decentralized energy management system. The MAS (Multi-Agent Systems) represents the paradigm of the decentralized system. The JADE platform is used to develop the MAS due to its general domain of application, open source and free license software, interface with MATLAB and the computability with the FIPA (Foundation of Intelligent Physical Agent) standards. The JADE based energy management system balances the energy between the generation (marine-current energy conversion system) and the demand side (residential load profile) during the stand-alone and the grid-connected modes of operation. The proposed model of the SGAM can be considered as a pilot case study that enables the detailed analysis and the applications of the different smart grid research directions.