Les composants passifs, représentent actuellement une butée importante en terme de volume occupé, de pertes et de faisabilité de l'intégration. De nouvelles structures électromagnétiques proposent de marier les trois composants habituellement rencontrés dans les convertisseurs sous la forme d'un seul composant baptisé LCT, assurant simultanément trois fonctionnalités : inductance-condensateur-transformateur. Nous avons dimensionné deux structures intégrées de prototypes LCT (bobiné & planar), employant, tous deux, une nouvelle topologie de circuit magnétique. En nous basant sur ces réalisations de composants passifs intégrées ainsi que sur une réalisation discrète, diverses approches sont proposées pour mieux estimer les pertes dans ces composants afin de pouvoir réaliser une étude comparative sur chacun des dispositifs. En particulier, la caractérisation fine du LCT en vue d'obtenir les éléments d'un schéma équivalent constitue un moyen d'atteindre ce résultat.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-24T13:47:14Z No. of bitstreams: 1 FRANCISCO FERREIRA DANTAS FILHO - TESE (PPGEP) 2013.pdf: 1757426 bytes, checksum: 5a54b650a305bfccca48540f2323f279 (MD5) / Made available in DSpace on 2018-09-24T13:47:14Z (GMT). No. of bitstreams: 1 FRANCISCO FERREIRA DANTAS FILHO - TESE (PPGEP) 2013.pdf: 1757426 bytes, checksum: 5a54b650a305bfccca48540f2323f279 (MD5) Previous issue date: 2013-04-20 / CNPq / O presente trabalho discorre sobre uma alternativa para mitigar o problema do Lodo de Esgoto Sanitário – LES. Esse resíduo influencia negativamente de várias formas o meio ambiente, destacando-se a poluição das águas superficiais e subterrâneas. Teve como objetivo utilizar a biomassa presente no LES para a produção de combustíveis (Bio-óleo e Carvão). Tratou-se de um estudo experimental com a biomassa obtida na Estação Experimental de Tratamento Biológico de Esgotos Sanitários – EXTRABES, localizada na cidade de Campina Grande – PB. O experimento foi realizado em duas etapas: a primeira correspondente ao estudo termogravimétrico e cinético do LES; a segunda, a obtenção do bio-óleo e carvão oriundo da pirólise do LES, realizado no LABCON, instalado na Universidade Federal Fluminense – UFF. Os resultados obtidos do estudo termogravimétrico nas três razões de aquecimento 5,10 e 15ºC.min-1, constatam uma estabilidade térmica a 30ºC sobre atmosferas de ar sintético e N2. No estudo cinético determinaram-se os seguintes parâmetros: Energia de Ativação (Ea), Fator de frequência (A-1), Desvio padrão (sd) e o Coeficiente linear (r), que foram calculados por termogravimetria pelos métodos Coats-Redfern (CR); Madhusudanan (MD); Van Krevelen (VK) e Horowitz-Metzger (HM). Os espectros de FTIR da amostra do LES apresentaram bandas referentes à água, matéria orgânica e óxidos de silício. O bio-óleo foi obtido através do processo da conversão à baixa temperatura, em atmosfera de nitrogênio, atingindo 380°C com tempo de detenção de 2h. O proc esso de pirólise do LES resultou em 9% de bio-óleo, 57% de carvão e 34% de água de pirólise. Observou-se que o bio-óleo obtido é uma mistura complexa de hidrocarbonetos alifáticos, aromáticos, esteróides, compostos oxigenados e nitrogenados, que foi identificada pelas técnicas FTIR, RMN 1H, CG-EM. O carvão apresentou baixa área superficial, não sendo considerado potencialmente bom suporte catalítico, tanto pela metodologia de Langmuir, SLANG 0,748 m2.g-1 quanto por BET, SBET = 0,695m2.g-1. Os resultados confirmam que à Conversão à Baixa Temperatura é uma técnica promissora, tanto para o destino do LES, quanto para obtenção de biocombustíveis. / The present study discusses an alternative to mitigate Sewage Sludge – SS problem. This residue adversely affects the environment in various ways, highlighting pollution of surface and groundwater. It aimed to use the biomass present in the SS for fuel production (Biooil and coal). It was an experimental study with biomass obtained from the Estação Experimental de Tratamento Biológico de Esgotos Sanitários – EXTRABES, located in the city of Campina Grande – PB. The experiment was conducted in two stages: first corresponding to thermogravimetric and kinetic study of the SS; second, obtainment of biooil and coal originated from the pyrolysis of SS, conducted at LABCOM, installed at the Fluminense Federal University – FFU. The results obtained from the thermogravimetric study in the three heating rates 5, 10 and 15oC min-1, found a thermal stability at 30°C on atmospheres of synthetic air and N2. In the kinetic study the following parameters were determined: Activation Energy (Ea), frequency factor (A-1), standard deviation (sd) and linear coefficient (r), that were calculated by thermogravimetry by the Coats-Redern (CR); Madhusudanan (MD); Van Krevelen (VK) and Horowitz-Metzger (HM) methods. The FTIR spectrums from the SS sample presented bands related to water, organic matter and silicon oxides. The biooil was obtained through the conversion at low temperature process, in nitrogen atmosphere, reaching 380oC with holding time of 2h. The pyrolysis process of the SS resulted in 9% of biooil, 57% of coal and 34% of pyrolysis water. It was observed that the biooil obtained is a complex mixture of aliphatic hydrocarbons, aromatics, steroids, nitrogenous and oxygenated compounds, which was identified by the FTIR, RMN 1H, CG-EM techniques. The coal presented low superficial area, not being considered a potentially good catalytic support, by the Langmuir methodology, SLANG 0,748 m2.g-1 as well as the BET, SBET = 0,695m2.g-1. The results confirm that the Conversion at Low Temperature is a promising technique, for both the destination of the SS as well as for the obtainment of biofuels.

The usage of navigation meshes for path planning in games and otherdomains is a common approach. One type of navigation mesh that recently has beendeveloped is the Local Clearance Triangulation (LCT). The overall aim of the LCT isto construct a triangulation in such a way that a property called theLocal Clearancecan be used to calculate a path in a more efficient and cheap way. At the time ofwriting the thesis there only exists one solution that creates an LCT, this solution isonly using the CPU. Since the process of creating an LCT involves the insertion ofmany points and edge flips which only affects a local area it would be interesting toinvestigate the potential performance gain of using the GPU.Objectives.The objective of the thesis is to develop a GPU version based on thecurrent CPU LCT solution and to investigate in which cases the proposed GPU al-gorithm performs better.Methods.A GPU version and a CPU version of the proposed algorithm has beendeveloped to measure the performance gain of using the GPU, there are no algorith-mic differences between these versions. To measure the performance of the algorithmtwo tests have been constructed, the first test is called the Object Insertion test andmeasures the time it takes to build an LCT using generated test maps. The sec-ond test is called the Internal test and measures the internal performance of thealgorithm. A comparison between the GPU algorithm with an LCT library calledTriplanner was also done.Results.The proposed algorithm performed better on larger maps when imple-mented on a GPU compared to a CPU implementation of the algorithm. The GPUperformance compared to the Triplanner was faster in some of the larger maps.Conclusions.An algorithm that builds an LCT from scratch is presented. Theresults show that using the proposed algorithm on the GPU substantially increasesthe performance of the algorithm compared to when implementing it on a CPU.

The usage of navigation meshes for path planning in games and otherdomains is a common approach. One type of navigation mesh that recently has beendeveloped is the Local Clearance Triangulation (LCT). The overall aim of the LCT isto construct a triangulation in such a way that a property called theLocal Clearancecan be used to calculate a path in a more efficient and cheap way. At the time ofwriting the thesis there only exists one solution that creates an LCT, this solution isonly using the CPU. Since the process of creating an LCT involves the insertion ofmany points and edge flips which only affects a local area it would be interesting toinvestigate the potential performance gain of using the GPU.Objectives.The objective of the thesis is to develop a GPU version based on thecurrent CPU LCT solution and to investigate in which cases the proposed GPU al-gorithm performs better.Methods.A GPU version and a CPU version of the proposed algorithm has beendeveloped to measure the performance gain of using the GPU, there are no algorith-mic differences between these versions. To measure the performance of the algorithmtwo tests have been constructed, the first test is called the Object Insertion test andmeasures the time it takes to build an LCT using generated test maps. The sec-ond test is called the Internal test and measures the internal performance of thealgorithm. A comparison between the GPU algorithm with an LCT library calledTriplanner was also done.Results.The proposed algorithm performed better on larger maps when imple-mented on a GPU compared to a CPU implementation of the algorithm. The GPUperformance compared to the Triplanner was faster in some of the larger maps.Conclusions.An algorithm that builds an LCT from scratch is presented. Theresults show that using the proposed algorithm on the GPU substantially increasesthe performance of the algorithm compared to when implementing it on a CPU.

The usage of navigation meshes for path planning in games and otherdomains is a common approach. One type of navigation mesh that recently has beendeveloped is the Local Clearance Triangulation (LCT). The overall aim of the LCT isto construct a triangulation in such a way that a property called theLocal Clearancecan be used to calculate a path in a more efficient and cheap way. At the time ofwriting the thesis there only exists one solution that creates an LCT, this solution isonly using the CPU. Since the process of creating an LCT involves the insertion ofmany points and edge flips which only affects a local area it would be interesting toinvestigate the potential performance gain of using the GPU. The objective of the thesis is to develop a GPU version based on thecurrent CPU LCT solution and to investigate in which cases the proposed GPU al-gorithm performs better. A GPU version and a CPU version of the proposed algorithm has beendeveloped to measure the performance gain of using the GPU, there are no algorith-mic differences between these versions. To measure the performance of the algorithmtwo tests have been constructed, the first test is called the Object Insertion test andmeasures the time it takes to build an LCT using generated test maps. The sec-ond test is called the Internal test and measures the internal performance of thealgorithm. A comparison between the GPU algorithm with an LCT library called Triplanner was also done. The proposed algorithm performed better on larger maps when imple-mented on a GPU compared to a CPU implementation of the algorithm. The GPU performance compared to the Triplanner was faster in some of the larger maps. An algorithm that builds an LCT from scratch is presented. Theresults show that using the proposed algorithm on the GPU substantially increasesthe performance of the algorithm compared to when implementing it on a CPU.

Les pegmatites à éléments rares de type LCT sont depuis longtemps étudiées et exploitées pour leurs gemmes et les métaux rares qu’elles contiennent. Malgré de nombreuses études réalisées sur les processus d’enrichissement en éléments rares, ou les mécanismes à l’origine de leurs textures, très peu d’études ont été dédiées aux mécanismes de mise en place des pegmatites et à leur répartition spatiale à l’échelle du champ. Afin de déterminer les mécanismes moteurs à l’origine de l’ascension de ces magmas, une étude multidisciplinaire a été menée sur 3 champs de pegmatites à éléments rares, répartis à l’échelle de la chaîne Varisque. Les résultats démontrent la proximité entre la localisation des pegmatites minéralisées et l’intensité de la déformation encaissante. De plus, la mise en place de ces magmas semble facilitée par un certain mode de fracturation. La modélisation numérique de la mise en place des magmas dans ces zones crustales fragilisées indique que l’ascension est facilitée par leurs faibles viscosité et densité, mais aussi par des perméabilités crustales très élevées (> 10⁻¹² m²), à des profondeurs de l’ordre de 10 km. Enfin, d’après les signatures isotopiques du Li mesurées sur des micas pegmatitiques, le lithium ne fractionne pas depuis le granite voisin, jusqu’aux pegmatites les plus différenciées, puisque les valeurs δ⁷Li (‰) sont toutes comprises dans une gamme de - 2 à + 2 ‰, similaire à celle rencontrée dans les granites orogéniques. Nous suggérons donc que la genèse des magmas pegmatitiques est commune à celle des granites hyperalumineux. Les mécanismes de fracturation et d’attraction (« magma-pumping ») sont envisagés pour avoir favorisé l’ascension de ces magmas résiduels, enrichis en éléments rares, de faibles volumes, au cours de transitions brutales et de courtes durées (~ 10³ ans), de la perméabilité. L’ensemble de ces résultats permet de remettre en question le modèle du granite parent classiquement utilisé pour la prospection de ces gisements, et de proposer un modèle revisité couplant la genèse et la mise en place de ces magmas. / LCT-type rare-element pegmatites have long been studied and exploited for their gems and rare metals they contain. Despite many studies about the rare-element enrichment, or about the mechanisms leading their exotic textures, very few studies have been dedicated to the mechanisms controlling their emplacement and their spatial distribution at the scale of the pegmatite field. To better investigate the origin of ascent-driving mechanisms of these magmas, a multidisciplinary study was conducted on 3 rare-element pegmatite fields across the Variscan belt. The results demonstrate the spatial proximity of the rare-metals-rich pegmatites with the intensity of deformation of the hosting rocks. In addition, spatial statistical analyses suggest that the emplacement of such magmas has been facilitated by fracture-controlled model. According to numerical models, the rise of these pegmatite-forming melts along weakened crustal zones would be facilitated by their peculiar physico-chemical properties (low viscosity and density), but also by very high crustal permeability (> 10⁻¹² m²) at depths around 10 km. Finally, accordingly to Li isotope signatures measured on pegmatitic micas, lithium does not fractionate from neighbouring granite up to the more differentiated pegmatites, since all δ⁷Li (‰) fall within a range of - 2 to + 2 ‰, as for orogenic granites. Therefore, we suggest that the genesis these pegmatite-forming melts is common to that of peraluminous granites. Mechanisms of fracturation and magma-pumping may have favoured the rise of these low volumes of residual melts, enriched in rare-elements, during short periods (~ 10³ yrs) of strong permeability increase. These results question the granitic model commonly used for the exploration of this type of mineral deposits. We suggest a revisited model accounting for both genesis and emplacement controlling mechanisms of the pegmatite-forming melts.

Un grand effort a été réalisé ces dernières années dans la compréhension du champ d'écoulement et du transfert de chaleur dans les canaux de refroidissement internes présents dans les pales de turbine. En effet, des systèmes de refroidissement avancés ont non seulement conduit à l'augmentation de l'efficacité de la turbine à gaz en augmentant la température d'entrée de la turbine au-dessus de la température de fusion du matériau, mais également en augmentant la durée de vie de la turbine. Pour permettre de tels progrès, des techniques expérimentales et numériques modernes ont été largement appliquées afin d'interpréter et d'optimiser l'aérodynamique et le transfert de chaleur dans les canaux de refroidissement internes. Cependant, les données disponibles sont limitées dans le cas des canaux de refroidissement internes dans les aubes de rotor de turbine. Les gradients de rotation et de température introduisent des forces de flottabilité de type Coriolis et centripète dans le référentiel rotatif, modifiant de manière significative l'aérothermodynamique par rapport aux passages stationnaires. Dans le cas des pales de rotor de turbine, la plupart des investigations sont soit basées sur des mesures ponctuelles, soit sont contraintes à des régimes de rotation faibles. L'objectif principal de ce travail est d'étudier le débit détaillé et le transfert de chaleur d'un canal de refroidissement interne à des conditions de fonctionnement dimensionnelles sans moteur représentatives. Ce travail introduit une section d'essai en laboratoire qui exploite des canaux à nervures sur un large éventail de nombres de Reynolds, de rotation et de flottabilité. Dans le présent travail, le nombre de Reynolds va de 15,000 à 55,000, le nombre de rotation maximum est égal à 0.77 et le nombre maximal de flottabilité est égal à 0.77. La nouvelle installation expérimentale consiste en une conception polyvalente qui permet l'interchangeabilité de la géométrie testée, de sorte que les canaux de différents rapports d'aspect et les géométries de nervure peut être facilement installé. La particle image velocimetry et la thermographie à cristaux liquides sont effectuées pour fournir des mesures précises de vitesse et de transfert de chaleur dans les mêmes conditions opératoires, ce qui conduit à un ensemble de données expérimentales unique. De plus, des simulations à grands virages sont réalisées pour donner une image de l'ensemble du champ d'écoulement et compléter les observations expérimentales. En outre, l'approche numérique vise à fournir une méthodologie robuste qui est capable de fournir des prédictions haute-fidélité de la performance des canaux de refroidissement internes. / A great effort has been carried out over the recent years in the understanding of the flow field and heat transfer in the internal cooling channels present in turbine blades. Indeed, advanced cooling schemes have not only lead to the increase of the gas turbine efficiency by increasing the Turbine Inlet Temperature above the material melting temperature, but also the increase of the turbine lifespan. To allow such progresses, modern experimental and numerical techniques have been widely applied in order to interpret and optimize the aerodynamics and heat transfer in internal cooling channels. However, the available data is limited in the case of internal cooling channels in turbine rotor blades. Rotation and temperature gradients introduce Coriolis and centripetal buoyancy forces in the rotating frame of reference, modifying significantly the aerothermodynamics from that of the stationary passages. In the case of turbine rotor blades, most of the investigations are either based on point-wise measurements or are constraint to low rotational regimes. The main objective of this work is to study the detailed flow and heat transfer of an internal cooling channel at representative engine dimensionless operating conditions. This work introduces a laboratory test section that operates ribbed channels over a wide range of Reynolds, Rotation and Buoyancy numbers. In the present work, the Reynolds number ranges from 15,000 to 55,000, the maximum Rotation number is equal to 0.77, and the maximum Buoyancy number is equal to 0.77. The new experimental facility consists in a versatile design that allows the interchangeability of the tested geometry, so that channels of different aspect ratios and rib geometries can be easily fitted. Particle Image Velocimetry and Liquid Crystal Thermography are performed to provide accurate velocity and heat transfer measurements under the same operating conditions, which lead to a unique experimental data set. Moreover, Large Eddy Simulations are carried out to give a picture of the entire flow field and complement the experimental observations. Additionally, the numerical approach intends to provide a robust methodology that is able to provide high fidelity predictions of the performance of internal cooling channels.

The Dumper Dew is a newly discovered pegmatite located on the eastfacing slope of Uncle Tom Mountain in Oxford County, Maine. It is a geochemically evolved LCT-type pegmatite petrogenetically linked to the middle Paleozoic Sebago batholith. Shallow emplacement of the Dumper Dew is evidenced by abundant miarolitic cavities found in the pegmatite. The sheet-like structure of the pegmatite coupled with its intrusion in lowmetamorphic grade country rock suggests rapid crystallization. Northern portions of the wall zone and intermediate zones have undergone hydrothermal alteration by the migration of late-stage fluids. The pegmatite hosts a diverse assemblage of rare-element mineral phases due to its high degree of geochemical fractionation. Trends of geochemical fractionation of individual mineral phases such as K-feldspar, muscovite, garnet, apatite, beryl, spodumene, triphylite-lithiophilite, tourmaline, cassiterite, and columbite-tantalite were attained via instrumentation assay. These trends illustrate an enhanced degree of magmatic differentiation relative to other pegmatites in the area.

<p>Many information technology artefacts can be found in today’s cars. The interaction with these artefacts is the driver’s secondary task while driving the car in a safe way is the primary task. When designing interfaces for in-vehicle usage, measures have to be taken in order to make the interaction with the artefact suit the in-vehicle environment. One of these measures is to have the appropriate screen density level, which is the amount of information present on the screen.</p><p>This thesis compares the usability of two integrated in-vehicle display prototypes, one with low screen density and one with high screen density. The usability comparison considers both safety and user preferences. Safety was measured by a Lane Change Test (LCT) which measures distraction of a primary task while performing a secondary task, and user preferences was measured with a questionnaire. Before the comparison was made, controls and a graphical user interface were designed.</p><p>Results showed no significant difference in driver distraction between performing tasks on the high screen density display and the low screen density display. However, a vast majority of the users preferred high screen density over low. Furthermore, the distraction levels for both the high and the low screen density displays were below the proposed 0.5 meter limit for allowed driver distraction. The results indicate that in-vehicle displays can have a high level of screen density without imposing a level of distraction on the driver that is unsuitable for driving.</p>

Many information technology artefacts can be found in today’s cars. The interaction with these artefacts is the driver’s secondary task while driving the car in a safe way is the primary task. When designing interfaces for in-vehicle usage, measures have to be taken in order to make the interaction with the artefact suit the in-vehicle environment. One of these measures is to have the appropriate screen density level, which is the amount of information present on the screen. This thesis compares the usability of two integrated in-vehicle display prototypes, one with low screen density and one with high screen density. The usability comparison considers both safety and user preferences. Safety was measured by a Lane Change Test (LCT) which measures distraction of a primary task while performing a secondary task, and user preferences was measured with a questionnaire. Before the comparison was made, controls and a graphical user interface were designed. Results showed no significant difference in driver distraction between performing tasks on the high screen density display and the low screen density display. However, a vast majority of the users preferred high screen density over low. Furthermore, the distraction levels for both the high and the low screen density displays were below the proposed 0.5 meter limit for allowed driver distraction. The results indicate that in-vehicle displays can have a high level of screen density without imposing a level of distraction on the driver that is unsuitable for driving.