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In dieser Dissertation wird die Suche nach schweren neutralen pseudoskalaren A und skalaren H Higgs-Bosonen vorgestellt, die in gg-Fusionen erzeugt werden, und in ein Top-Antitop-Quark-Paar zerfallen. Gesucht wurde im vollständigen Datensatz von Proton–Proton-Kollisionen bei einer Schwerpunktsenergie von 8 TeV die vom ATLAS-Detektor am Large Hadron Collider aufgezeichnet wurde und einer integrierten Luminosität von 20.3 fb−1 entspricht. Der Signalprozess und der Haupthintergrund aus der Top-Quark-Paar-Produktion über starke gg-Fusionen-Prozesse, interferieren heftig, was zu einer Verzerrung des reinen Breit-Wigner-Resonanzpeak in eine Peak-Dip-Struktur führt. Diese Analyse ist die erste am LHC, die die Interferenz zwischen Signal und Hintergrundprozessen vollständig berücksichtigt. Die Suche stützt sich auf die statistische Analyse des invarianten Top-Quark-Paar-Massenspektrum, welches aus Ereignissen mit einem Elektron oder Myon mit hohem Transversalimpuls, einer hohen fehlenden Transversalenergie von dem nicht detektierten Neutrino und mindestens vier Jets rekonstruiert wird. In den Daten wird keine signifikante Abweichung vom erwarteten Standardmodell-Hintergrund beobachtet. Die Ausschließungsgrenzen wurden abgeleitet im Kontext des Typ II Two-Higgs-Doublet Model, für Higgs-Bosonen mit einer Masse von 500 und 750 GeV und mit niedrigerem tan(\beta)-Parameter, bei der tan(\beta) das Verhältnis der Vakuumerwartungswerte der beiden Higgs-Dublett-Felder ist. Diese Parameterregionen sind weitgehend unerforscht in Untersuchungen von beliebigen Endzuständen. / In this thesis a search is presented for heavy neutral pseudoscalar A and scalar H Higgs bosons, produced in gg fusion and decaying into a top-antitop quark pair. The search is conducted on the full proton-proton collisions dataset recorded by the ATLAS detector at the Large Hadron Collider at a centre-of-mass collision energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb−1. The signal process and the main background from top quark pair production via the gg fusion strong process, interfere heavily, distorting the signal shape from the pure Breit-Wigner resonance peak to a peak-dip structure. This analysis is the first one at the LHC that fully takes into account the interference between a signal and the background processes. The search relies on the statistical analysis of the top quark pair invariant mass spectrum, which is reconstructed in signal candidate events with a high-transverse momentum electron or muon, large missing transverse energy from the undetected neutrino and at least four jets. No significant deviation from the expected SM background is observed in data. Exclusion limits are derived in the context of the type-II Two-Higgs-Doublet Model, for Higgs boson masses of 500 and 750 GeV and in the low tan(\beta) parameter region, where tan(\beta) is the ratio of the vacuum expectation values of the two Higgs doublet fields. These parameter regions have been largely unexplored by searches in any final state.

Pour les applications aéronautiques, les fibres en céramique piézoélectrique à âme métallique permettent d'imaginer des solutions pour avoir des dispositifs actifs et des capteurs complétement intégrés dans des structures, telles que les composites renforcés par des fibres.La démarche de cette étude est d'élaborer et de caractériser de telles fibres qui présentent de nombreux avantages : l'activation en mode radial permet d'utiliser de faibles tensions de commandes, l'utilisation d'un cœur et d'une matrice conducteurs permet de s'affranchir du dépôt d'électrodes et de garantir leur continuité, la présence d'un coeur métallique améliore la résistance mécanique de la fibre, l'utilisation sous forme de fibres fines et longues permet de l'intégrer à des profils de formes complexes sur de grandes longueurs. Dans un premier temps, le procédé d'enduction est utilisé pour la réalisation de ces fibres en déposant des particules céramiques à base de titano-zirconate de plomb (PZT) sur des fils de platine. Le développement et l'optimisation d'un procédé multicouche permet de réaliser des fibres avec des épaisseurs parfaitement contrôlées pour obtenir les capacités de déformations optimales en alternant des cycles dépôt/traitement thermique avant une opération de frittage finale. La caractérisation d'échantillons massifs traités dans les mêmes conditions permet de s'assurer des propriétés piézoélectriques atteintes pendant les différents traitements thermiques. Les caractérisations électromécaniques réalisées sur les fibres permettent de vérifier le comportement en tant qu'actionneur et que capteur, bien qu'il s'avère difficile de remonter aux caractéristiques intrinsèques des fibres.Dans un second temps, une réflexion est menée sur les moyens à mettre en oeuvre pour envisager un développement à grande échelle de ce type de fibre. Dans ce sens, des expérimentations sur la mise en place du procédé continu de coextrusion avec un polymère chargé sont menées, de même que sur la réduction de la température de frittage à l'aide d'additifs pour substituer les fils en platine, mais aussi sur la réduction du temps de frittage à l'aide de techniques non conventionnelles comme le frittage laser et le frittage micro-ondes. Ces investigations ouvrent des pistes sérieuses pour imaginer une production continue de fibres piézoélectriques à âme métallique.Enfin, des travaux de modélisation par éléments finis du comportement de ces fibres, intégrées ou non dans une structure, permettent de mettre en évidence l'influence du dimensionnement des fibres sur les déformations résultantes, en fonction notamment de l'épaisseur du matériau actif déposée et des propriétés élastiques des différents éléments. Différentes configurations sont imaginées pour utiliser ces fibres dans des structures en tant qu'actionneur et capteur. / Metal core piezoelectric fibres are suitable for active devices and sensors fully embedded in structuresas fibres reinforced polymers for aeronautic applications.The aim of this study is to develop and characterize such fibres that have many advantages: radial mode activation allows the use of low voltage control, the use of a core and a conductive matrix eliminates the deposition of electrodes and the necessity to maintain their continuity, the presence of a metal core improves the mechanical strength of the fibre, the use of thin and long fibres permits their integration in profiles with complex shapes over long distances.In a first step, a dip-coating process is used to realize such fibres by depositing ceramic particles based on lead zirconium titanate (PZT) on platinum wire. The development and optimization of a multilayer process, by alternating deposition cycles / heat treatment prior to the final sintering step, lead to the production of fibres with perfectly controlled thickness in order to obtain optimal strain capability. Characterization of bulk samples under the same thermal conditions allows to measure equivalent piezoelectric properties as fibres submitted to the same heat treatments. Electromechanical characterizations performed on the fibres confirm their behaviour as actuator and sensor, although it is still difficult to determine the effective piezoelectric properties of the fibres.In a second step, the possibility to develop a large-scale production of this type of fibre is investigated.In this regard, experiments are carried on coextrusion process with a PZT loaded polymer, as well as the reduction of the sintering temperature by using additives to replace the platinum core. In addition, reducing the sintering time using unconventional techniques such as laser sintering and microwave sintering are investigated. It is then open serious leads to imagine a continuous production of metal core piezoelectric fibres.Finally, a finite element modelling approach of the behaviour of these fibres, integrated or not in a structure, allows to highlight the influence of fibre sizing on the resulting strains, in particular according to the thickness of the active deposited material and elastic properties of the individual elements (metal core, matrix). Different configurations are analysed to use these fibres in structures as actuator and sensor.

O processo industrial não-contínuo de zincagem por imersão a quente (ZIQ) pode ocasionar a contaminação superficial do aço-carbono zincado por imersão a quente (AZIQ) com resíduos de cloreto. Estes resíduos, se não forem efetivamente eliminados, podem influenciar negativamente no desempenho dos esquemas de pintura dos sistemas dúplex (zincagem mais pintura). Sabe-se que no processo de ZIQ, a cromatização é amplamente utilizada, entretanto, o efeito que este pós-tratamento exerce no desempenho dos esquemas de pintura ainda não é bem estabelecido. Neste contexto, este trabalho teve como objetivos: I - verificar o grau de contaminação no AZIQ com sal de cloreto devido ao próprio processo de ZIQ; II - verificar os efeitos da contaminação com sal de cloreto e da cromatização do processo ZIQ no desempenho de tintas aplicadas sobre o AZIQ; e III – determinar pré-tratamentos para pintura adequados para o bom desempenho das tintas aplicadas sobre o AZIQ. A metodologia adotada para alcançar o objetivo I envolveu a zincagem de chapas de aço-carbono em diferentes prestadores de serviço de ZIQ, em diferentes condições. Estas chapas zincadas foram analisadas por microanálise química qualitativa por espectrometria de dispersão de energia (EDS) em microscópio eletrônico de varredura (MEV) e pela determinação dos teores de cloreto superficiais, por método de extração com água em ebulição. A partir dos resultados obtidos para se alcançar o objetivo I, foi possível definir as condições no processo de ZIQ que potencialmente causam maior contaminação da superfície do AZIQ com sal de cloreto. Assim, para se alcançar os objetivos II e III, chapas de aço-carbono foram zincadas naquelas condições de máxima contaminação com sal de cloreto e parte delas foi submetida ao pós-tratamento de cromatização. Em seguida, uma grande parte destas chapas zincadas (cromatizadas ou não) foi submetida aos pré-tratamentos para pintura de desengraxe com solvente orgânico, de hidrojateamento a alta pressão, de jateamento abrasivo ligeiro e de ação mecânica com esponja abrasiva e água quente. Finalmente, as chapas zincadas, incluindo as não submetidas aos pré-tratamentos, foram pintadas com uma demão de tinta de aderência mais uma demão de tinta de acabamento. As chapas zincadas e pintadas foram submetidas a ensaios acelerados (imersão em água destilada e exposição em câmara de umidade saturada) e não-acelerados de corrosão (exposição em estação de corrosão atmosférica) e avaliadas por meio dos ensaios tradicionais de acompanhamento de desempenho (grau de empolamento e ensaios de aderência de tinta) e eletroquímicos (medida de potencial de circuito aberto, curva de polarização e espectroscopia de impedância eletroquímica – E.I.E.). Algumas chapas zincadas, antes da pintura, foram submetidas aos ensaios de caracterização física (exame microestrutural e morfológico em MEV e rugosidade superficial), química microanálise por EDS, difração de raios X e teor de cloreto superficial pelo método de extração com água em ebulição) e eletroquímica. Os resultados obtidos, neste estudo, permitiram verificar que a aplicação adicional de sal cloreto de amônio sólido durante o processo de ZIQ tende a aumentar o grau de contaminação superficial do AZIQ com cloreto e, as etapas de resfriamento e/ou de cromatização do processo também contribuem para esta contaminação. No geral, o desempenho do AZIQ cromatizado teve desempenho inferior em relação ao não-cromatizados. O hidrojateamento a alta pressão e a lavagem com água e ação mecânica foram os prétratamentos que proporcionaram os melhores desempenhos dos esquemas de pintura. / The batch galvanizing process (BGP) can lead to surface contamination of hot-dip galvanized steel (HDGS) with chloride residues. If these residues are not effectively eliminated, they can influence negatively on the performance of duplex systems (galvanizing plus painting). It is known that the chromate quenching is widely used in the BGP, however the effect of this post-treatment on the performance of duplex systems is not well established yet. In this sense, this work aimed: I – to verify the contamination degree of HDGS with chloride salt due to the BGP itself; II – to verify the effects of the chloride salt contamination and chromate quenching on the performance of paints applied on HDGS; and III – to determine the suitable surface preparation for painting in order for obtaining a good paint performance applied on HDGS. The adopted methodology to achieve goal I involved the galvanizing of steel plates in different service renderings with BGP, in different conditions. These HDGS plates were submitted to the qualitative energy dispersive microanalyses (EDS) in scanning electron microscopy (SEM) and to the determination of superficial chloride contents by the boiling water extraction method. From the obtained results, the conditions in the BGP that potentially lead to greater surface contamination of HDGS with chloride salt were determined. Thus, to achieve goals II and III, steel plates were galvanized under the maximum chloride salt contamination condition and part of them were submitted to chromate quenching. After that, a great part of these HDGS plates (chromated or non chromated quenching) was submitted to the surface preparations for painting through organic solvent cleaning, high pressure hydroblasting, sweep blasting and handled scrub cleaning with an abrasive sponge and hot distilled water. Finally, the HDGS plates, including those not submitted to the surface preparations for painting, were painted with one coat of primer plus one coat of finishing paint. The HDGS painted plates were submitted to accelerated (distilled water immersion and humidity chamber exposure) and non accelerated (atmospheric exposure) corrosion tests and their performance were verified by means of traditional tests (degree of blistering and paint adhesion) and electrochemical measurements (open circuit potential, polarization curve and electrochemical impedance spectroscopy – E.I.S.). Before painting, some HDGS plates were submitted to tests for physical (microstructural and morphological analyses in MEV and surface roughness), chemical (EDS, X-ray diffraction and superficial chloride contents by the boiling water extraction method) and electrochemical characterization. The obtained results allowed verifying that the additional application of solid ammonium chloride salt during the BGP tends to increase the degree of superficial chloride contamination of the HDGS and, the water and/or chromate quenching also contribute for this contamination. In general, the chromated HDGS presented worst performances. The high pressure hydroblasting and the handled scrub cleaning with an abrasive sponge and hot distilled water were the surface preparations for painting that provided the best performances of paint systems.

<p>U ovoj doktorskoj disertaciji je predstavljena je nova metoda za<br />detekciju propada napona, zasnovana na Rekurentnoj<br />neuronskoj mreži i analizi u harmonijskom domenu. Metoda je<br />namenjena za primenu u savremenim distributivnim mrežama<br />koje sadrže obnovljive izvore, i u skladu sa tim je optimizovana i<br />testirana. Pametna metoda postiže izuzetne rezultate u brzini<br />detekcije, sa prosečnim vremenom detekcije manjim od 1 ms, uz<br />izuzetnu pouzdanost (preko 97%). U doktorskoj disertaciji<br />dokazana je i druga hipoteza, a to je da je moguće predvideti<br />dubinu propada algoritmom zasnovanim na harmonijskoj analizi.</p> / <p>In this PhD thesis, a novel method for the detection of voltage dips<br />(sags), based on the Recurrent Neural Network and analysis in the<br />frequency domain, is presented. The method is intended for use in<br />the modern distribution grids that contains renewable sources, and<br />accordingly it is optimized and tested. The smart method achieves<br />exceptional results in detection speed, with an average detection<br />time of less than 1 ms and with high reliability (over 97%). In the<br />PhD thesis, another hypothesis is proved, which claims that is<br />possible to predict the depth of dip with algorithm based on the<br />harmonic analysis.</p>

Orientador: Erivaldo Antonio da Silva / Resumo: O processamento digital de imagens (PDI) consiste em uma área de grande interesse científico. Em Cartografia, o PDI é muito utilizado para extração de feições cartográficas de interesse presentes nas imagens de sensoriamento remoto (SR). Dentre as feições cartográficas, a detecção de malhas viárias é de grande interesse científico, pois proporciona a obtenção de informações atualizadas e acuradas para a realização de planejamentos urbanos. Devido à sua importância, a literatura científica possui diversos trabalhos propondo diferentes metodologias de extração de malhas viárias em imagens digitais. Dentre as metodologias, é possível encontrar metodologias propostas baseadas em lógica fuzzy, em detector de bordas e crescimento de regiões, por exemplo. Contudo, os estudos existentes focam na aplicação da metodologia de extração para determinadas áreas ou situações e utilizam recortes da imagem em seus estudos devido à grande quantidade de informações contidas nessas imagens. O avanço tecnológico proporcionou que imagens de SR sejam adquiridas com alta resolução espacial, espectral e temporal. Esse fato produz uma grande quantidade de dados a serem processados durante estudos desenvolvidos nessas imagens, o que acarreta um alto custo computacional e, consequentemente, um alto tempo de processamento. Na tentativa de reduzir o tempo de execução das metodologias de extração, os desenvolvedores dedicam esforços na redução da complexidade dos algoritmos e na utilização de outros recurs... (Resumo completo, clicar acesso eletrônico abaixo) / Resumen: El procesamiento digital de imágenes (PDI) consiste en un área de gran interés científico en diferentes áreas. En Cartografía, el PDI es muy utilizado en estudios de teledetección para extracción de los objetos cartográficos de interés presentes en las imágenes orbitales. Entre los objetos cartográficos de interés, la detección de redes viales se ha vuelto de gran interés científico proporcionando la obtención de informaciones actualizadas y precisas para la realización de planificaciones urbanas, por ejemplo. En este sentido, la literatura científica posee diversos trabajos proponiendo diferentes metodologías de extracción de redes viales en imágenes orbitales. Es posible encontrar metodologías propuestas basadas en lógica fuzzy, detector de bordes y crecimiento por región, por ejemplo. Sin embargo, los estudios existentes se centran en la aplicación de la metodología de extracción para determinadas áreas o situaciones y utilizan recortes de la imagen orbitales en sus estudios debido a la gran cantidad de informaciones contenidas en esas imágenes. Además, el avance tecnológico proporcionó que las imágenes de teledetección se adquieran con altas resoluciones espacial, espectral y temporal. Este hecho produce una gran cantidad de datos a ser procesados durante estudios desarrollados en esas imágenes, lo que acarrea en un alto costo computacional y, consecuentemente, un alto tiempo de procesamiento. En el intento de reducir el tiempo de respuesta de las metodologías de extracci... (Resumen completo clicar acceso eletrônico abajo) / Abstract: Digital image processing (DIP) consists of an area of great scientific interest in different areas. In Cartography, the DIP is widely used in remote sensing studies to extract cartographic features of interest present in orbital images. Among the cartographic features, the detection of road networks has become of great scientific interest, since it can provide accurate and updated information for urban planning, for example. In this sense, the scientific literature has several works proposing different methodologies of extraction of road networks in orbital images. It is possible to find proposed methodologies based on fuzzy logic, edge detector and growth by region, for example. However, the existing studies focus on the application of the extraction methodology to certain areas or situations and use orbital image cuts in their studies due to the large amount of information contained in these images. In addition, the technological advance has allowed the acquisition of remote sensing images with high spatial, spectral and temporal resolutions. This fact produces a large amount of data to be processed during studies developed in these images, which results in a high computational cost and, consequently, a high processing time. In an attempt to reduce the response time of the extraction methodologies, the developers dedicate efforts in reducing the complexity of the algorithms and in using some available hardware resources suggesting solutions that include software and hardwar... (Complete abstract click electronic access below) / Doutor

Les travaux présentés dans ce manuscrit traitent des mécanismes de croissance associés au dépôt de nanofils d’oxyde de zinc (ZnO) en bain chimique. Cette technique de croissance, attractive de par sa facilité de mise en œuvre et son coût limité, consiste à immerger un substrat dans une solution de précurseurs portée à basse température (typiquement 90°) pendant quelques heures. Le dépôt préalable d’une fine couche de ZnO fortement texturée est nécessaire à l’obtention de la morphologie nanofils et il est donc nécessaire de maîtriser le processus de croissance associé. Dans un souci de cohérence, la méthode sol-gel dite de trempage consistant à immerger le substrat dans une solution de précurseurs avant de recuire la couche ainsi déposée est ici adoptée. Le ZnO, sous sa morphologie nanofils, est actuellement fortement étudié du fait de son fort potentiel applicatif. Typiquement, il peut être utilisé en tant que brique de basse dans la réalisation de cellules solaires de types Grätzel ou à absorbeur extrêmement fin. Dans ce contexte, il est nécessaire que les nanostructures élaborées présentent des propriétés physiques attractives et ces dernières doivent donc être finement caractérisées. Dans un premier temps, l’influence des paramètres expérimentaux associés au processus de trempage sur les propriétés morphologiques et structurales de films minces de ZnO déposés via ce processus est quantifiée. Il est montré à cette occasion que dans des conditions extrêmes de recuits, les couches évoluent vers une morphologie de type fil. Fort des conclusions obtenues, les mécanismes régissant la croissance de nanofils de ZnO en bain chimique, et plus particulièrement l’influence de la surface de nucléation sur ces derniers, sont étudiés. La possibilité d’obtenir des nanofils localisés et parfaitement alignés à travers la réalisation de masques est démontrée. L’ensemble des nanostructures élaborées (couches et nanofils) sont caractérisées par photoluminescence afin de pouvoir estimer leur qualité structurelle et d’étudier les défauts en présence. Pour finir, une étude plus fondamentale consistant à suivre in situ l’évolution des nanofils au cours de la croissance par rayonnement synchrotron est proposée avec une attention toute particulière aux phénomènes de polarité. / ZnO nanowires are of strong interest in the realization of solar cells based on type-II band alignment. They can be grown by chemical bath deposition, a technique in which the substrate is seeded with ZnO nanoparticles by dip-coating and then placed in a precursor solution heated at 90°C for a couple of hours. In this document, we will discuss the nucleation and growth mechanisms associated with this low cost technique. In particular, we will see how the seed layer morphology can drive the one of the nanowires. Also, advanced characterization by photoluminescence and synchrotron radiation will be performed on the grown nanostructures.

L'oxyde de nickel est l'un des matériaux électrochromes les plus utilisés dans le domainedes fenêtres intelligentes qui contrôlent la lumière et la chaleur provenant de l'extérieur versl'intérieur des bâtiments. Il est important de mentionner que l’oxyde de nickelstoechiométrique est un isolant à température ambiante. Les propriétés microstructurales,chimiques, optiques et électrochromes des couches minces dépendent fortement du procédéde préparation et traitement final. En outre, l’un des principaux défis consiste à fabriquer lescouches minces sur des substrats souples afin de fabriquer des fenêtres électrochromes degrande taille ce qui demande un traitement à T ambiante. A cet égard peu d’étudesbibliographiques ont évalué l’effet du traitement par les rayonnements UV sur les propriétésdes couches électrochromes. Dans ce travail, des couches minces d'oxyde de nickel (NiO) ontété préparées par la méthode Sol-Gel associée aux techniques de dépôts par centrifugation(spin-coating) et par trempage-retrait (dip-coating). L’ajustement des paramètresexpérimentaux relatifs à ce procédé (la concentration du précurseur, la nature du solvant et dustabilisant, le nombre de couches déposées et le type des traitement final (calcinationà 300 °C ou traitements UV) a permis d’optimiser les conditions de préparation des couchesminces et par la suite de contrôler les caractéristiques chimiques, microstructurales et optiquesdes couches développées. Cette étude a montré qu'une concentration de 0,3 M d'acétate denickel, le méthanol comme solvant et le triton X-100 en tant que stabilisant conduisent à unecouche mince NiO avec les meilleures performances optiques. Les caractérisations par lestechniques (DRX, ATG, FT-IR, XPS et GDOES) ont particulièrement mis en évidence le rôledes conditions de traitement final sur la composition et la morphologie des couches d’oxydede nickel élaborées. La DRX a montré qu’elles sont faiblement cristallisées et que la structuredevient plus amorphe avec le traitement UV. La spectrométrie UV-visible et les CV ont révéléque les couches traitées par UV en utilisant une lampe de 30 W pendant 5 h (UV-30W-5h)possèdent le contraste optique le plus élevé et la meilleure stabilité électrochimique. L'analysemorphologique a montré que les couches minces déposées par la technique de spin coatingsouffrent de la formation de fissures et d’une hétérogénéisation de la surface. Pour résoudre ceproblème, le procédé de spin-coating a été remplacé par la technique dip-coating tout enconservant les paramètres optimisés précédemment. Cette technique a permis de produire descouches minces plus homogènes et moins fissurées. D'autre part, pour continuer à améliorerles propriétés électrochromes, ces couches ont été dopées par le lithium. Les résultats obtenusont montré l’importance de l’addition de Li sur l’amélioration des propriétés électrochromesde Li : NiO cyclé dans KOH comme électrolyte. En effet, une variation de la transmittanceΔT de 70% (à 450 nm) a été obtenue dans les couches minces 8 % Li: NiO. Le résultat quiressort des caractérisations FT-IR et ATG, porte sur le fait que les couches calcinéescontiennent moins de composés organiques, à l’inverse de celles traitées par UV riches enmatière organique. L'analyse XPS a montré que la teneur en Ni2+ est plus élevée dans lescouches dopées. L’analyse GDOES a montré une distribution homogène de Li dans toutel’épaisseur de la couche. Toutefois, les couches minces de 8% de Li: NiO traitées par UV-30W-5h souffrent d’une dégradation de leurs performances électrochromes dans le KOHaprès quelques cycles, pour cette raison, elles ont été cyclées dans d’autres électrolytesliquides ioniques, tels que le LiTFSI-EMITFSI, le NaTFSI-EMITFSI et le KTFSI-EMITFSI.Les meilleures propriétés électrochromiques ont été obtenues avec l'électrolyte KTFSIEMITFSI.Ce résultat important représente une bonne perspective pour l'avenir. / Nickel oxide is one of the most widely used electrochromic materials in the field of smartwindows that control light and heat from the outside to the inside of buildings. It is importantto mention that stoichiometric nickel oxide is an insulator at room temperature. Themicrostructural, chemical, optical and electrochromic properties of the films are highlydependent on the process of preparation and final treatment. In addition, one of the mainchallenges is the elaboration of thin films on flexible substrates suitable for electrochromicapplications which requires treatment at ambient T. In this respect, in literature, few studieshave reported the effect of UV treatment on the properties of electrochromic layers. In thiswork, thin films of nickel oxide (NiO) were prepared by the Sol-Gel method associated withspin-coating and dip-coating techniques. The adjustment of the experimental parametersrelating to this process (the concentration of the precursor, the nature of the solvent and thestabilizer, the number of deposited layers and the type of final treatment (calcination at300 °C or UV treatments) made it possible to optimize conditions for the preparation of thinlayers and subsequently to control their chemical, microstructural and optical characteristics.This study showed that a concentration of 0.3 M nickel acetate, methanol as solvent and triton100-X as a stabilizer lead to NiO thin film with the highest optical properties. The techniquesof characterizations (DRX, ATG, FT-IR, XPS and GDEOS) have particularly highlighted therole of the final treatment conditions on the composition and the morphology of the preparednickel oxide thin films. The XRD results showed that they are weakly crystallized and thestructure becomes even more amorphous for UV treated samples. UV-visible spectrometryand cyclic voltammetry revealed that UV-treated thin films using a lamp of 30 W for 5 h(UV-30W-5h) have the highest optical contrast and the highest electrochemical stability.Morphological analysis (SEM) indicated that the thin films deposited by the spin-coatingtechnique suffer from crack formation and surface heterogenization. To solve this issue, thespin-coating process has been replaced by the dip-coating technique while retaining thepreviously optimized parameters. This technique has made it possible to produce thin filmsthat are more homogeneous and less cracked. On the other hand, to continue to improve theelectrochromic properties, these thin films were doped with lithium. The results showed theimportance of the addition of Li on the improvement of the electrochromic properties ofLi : NiO cycled in KOH as electrolyte. Indeed, a variation of the ΔT transmittance of 70 %was reached for the thin films 8 % Li : NiO. The result of the FT-IR and ATGcharacterizations showed that the calcined thin films contain lesser amount of organiccompounds compared to those treated by UV which still contains large amount of organicmatter. XPS analysis has shown that the Ni2+ content is higher in the doped layers. GDOESanalysis showed a homogeneous distribution of Li along the thickness of the thin film.However, 8% Li: NiO thin films treated with UV-30W-5h suffer from a degradation of theirelectrochromic performances in KOH after a few cycles. For this reason, their cyclingproperties have been investigated in a large range of electrolytes, based on ionic liquidincluding LiTFSI-EMITFSI, NaTFSI-EMITFSI and KTFSI-EMITFSI. The highestelectrochromic properties were obtained with KTFSI-EMITFSI as an electrolyte. Thisimportant result presents a good prospect for the future.

Static synchronous compensation (StatCom) is an application that utilizes a voltage source converter (VSC) to provide instantaneous reactive power support to the connected power system. Conventionally, StatComs are employed for reactive power support only. However, with the integration of energy storage (ES) into a StatCom, it can provide active power support in addition to the reactive power support. This thesis deals with the integration of ES into StatComs. The investigation involves the following aspects: possible benefits for power systems, main circuit design, and control strategies. As the basis of the investigation, a control scheme is proposed for two-level VSCs. It is a novel flux modulation scheme combined with the well-known deadbeat current control. The current controller is capable of controlling the positive sequence, the negative sequence, and the offset components of the converter current. With flux modulation, all the three above-mentioned components of the bus flux are controllable. This differs from the conventional voltage modulation scheme, in which only the positive and negative sequence components of the bus voltage are controllable. The difference between the proposed flux modulation scheme and the voltage modulation scheme is investigated regarding saturation of transformers in the connected system during fault recovery. The investigation shows that by controlling the offset component of the bus flux, the transformer saturation problem can be mitigated to a certain extent. The possible benefits of the additional active power support of StatComs are investigated through several case studies. Different active power compensation schemes are proposed. First, active power compensation for sudden load changes in weak systems is investigated. The proposed control strategies are verified through computer simulations and through experiments in a real-time simulator. It is shown that with active power compensation, both the phase jumps and magnitude variations in the voltage at the PCC can be reduced significantly. Secondly, the power compensation of cyclic loads is investigated. The results show that the power quality at the connection point can be improved regarding both phase jumps and magnitude variations. In the third case study, the fault-recovery performance of an example system is investigated, showing that improved performance can be achieved by the additional active power support. ES devices such as capacitors, supercapacitors, and batteries exhibit considerable variation in the terminal voltage during a charging/discharging cycle. A direct connection of ES devices to the dc side of a VSC requires a higher voltage rating of the VSC. Thus, the cost of the VSC has to be increased. In this thesis, a dual thyristor converter topology is proposed to interface ES devices with the dc side of the VSC. First, a cost comparison is performed to compare the total cost of the whole system with and without the proposed interface topology. A cost comparison between various types of ES is also presented, providing a guideline for the choice of ES at energy levels where several alternatives exist. Then, the dynamics of systems with the proposed interface topology are investigated. Control strategies are proposed and verified by computer simulations. Two different control methods for the dual-thyristor converter are compared. / QC 20100819

Among global steel markets in recent years, China steel industry expands the fastest with the largest capacity and most fiercest competitions, also bringing the greatest impacts to global and Taiwan steel markets. A few aggressive Taiwan mills have set up their production facilities in China and commissioned. This study conducts in-depth analysis on the leading Taiwan middlestream galvanizers & coil coaters (the products are hot-dip galvanized & pre-painted steel sheets, hereinafter called ¡§galvanized & pre-painted steel¡¨). Besides, the steel works are categorized into Taiwan works, China works-Taiwan capital, China works-foreign capital, and China local works based on different capital sources. Analysis and evaluation are done in light of every activity in value chain. Six types of galvanizers & coil coaters are categorized based on different facilities and processes. Type I: Integrated galvanizers & coil coaters Type II: CSP galvanizers & coil coaters Type III: Independent galvanizers Type IV: Independent coil coaters Type V: Independent galvanizers & coil coaters Type VI: Independent full-process galvanizers & coil coaters Owing to their different market environments, development backgrounds, technologies, human resources and management, this study will analyze their strengths, strategies adopted, possible future development trends and potential challenges. This study especially focuses on one issue: in the atmosphere of competition and cooperation between steel mills in Taiwan and China, how China independent galvanizers & coil coaters-Taiwan capital and Taiwan parent company upgrade their competitiveness is crucial. Synthesizing related literature & theories, market & mill information and interviews, verifying by comparison, four conclusions are obtained as follows. 1. The more value chain activities a mill has, the more profits and stronger competitiveness it acquires. 2. Taiwan markets of galvanizing & pre-painted steel are already saturated. The competitiveness & development strategy a globalization enterprise should adopt is to increase its export percentages and establish offshore production bases. 3. For those mills setting up independent galvanizers & coil coaters in both China and Taiwan, the marketing strategies they should employ are described as follows. 3.1 Both China and Taiwan works receive orders and manufacture for their domestic markets. In terms of exports, only Taiwan parent company receives orders for both. But they export through Taiwan¡¦s existing channels globally. 3.2 To ally with different downstream industries and benefit each other. 3.3 China products are exported to ASEAN 10 nations, or 10+3, or 10+4, or any country that hasn¡¦t accuse China mills of dumping, whereas Taiwan products are sold to China, or any country that hasn¡¦t accuse Taiwan mills of dumping. 3.4 Products should be differentiated. Order receiving, production planning, lead-time and customer service should be flexible and elastic. 3.5 The chosen customers and suppliers must be big and strong in their region. Thus, the overall enterprise competitiveness is excellent. 4. In the past, steel companies self-expand to grow whereas today they grow via merger and acquisition. Any enterprise must have its value-creation strategy, i.e. it must have a growth strategy to react to the fierce market competitions. This study provides six recommendations for the competitiveness & growth strategies which could be adopted by domestic Taiwan independent galvanizers & coil coaters. 1. For the investors who invest in independent galvanizers & coil coaters for the first time, the first choice should be Type VI: independent full-process galvanizers & coil coaters. The second choice should be Type V: Independent galvanizers & coil coaters. Next, to set up an independent galvanizer is superior to an independent coil coater. 2. Independent Galvanizers & Coil Coaters should adopt the growth strategy that horizontal developing to a certain scale at the outset is the priority. Next, they should develop toward upstream instead of downstream. In order to eliminate capacity, they should ally with different downstream industries. 3. In the market of demand exceeding supply, mills usually self-expand to achieve larger scale. Nevertheless, when the market is oversupplied, it is recommended to adopt acquisitions. 4. Independent galvanizers & coil coaters choose the most beneficial investment items & scale and start their oversea development based on their growth strategies. 5. In the initial phase of plant construction, independent galvanizers & coil coaters should negotiate with upstream raw material suppliers regarding raw material supply matters. A good relationship should be built in order to secure stability of raw material sources. 6. To manage China mills-Taiwan capital and compete with other mills, the following measures are recommended. 6.1 To take advantage of the enterprise strength, develop specialized products and promote marketing features. 6.2 To promptly establish market reaction mechanism via the internationalization strategy of ¡§Integration-Responsiveness¡¨. 6.3 To employ human resources management to aid internationalization strategy. 6.4 Integration model created by overseas plant construction or acquisition can be adopted to integrate an enterprise¡¦s organization, culture and resources via dynamics management system.