The GMT-Consortium Large Earth Finder (G-CLEF) will be a cross-dispersed, optical band echelle spectrograph to be delivered as the first light scientific instrument for the Giant Magellan Telescope (GMT) in 2022. G-CLEF is vacuumenclosed and fiber-fed to enable precision radial velocity (PRV) measurements, especially for the detection and characterization of low-mass exoplanets orbiting solar-type stars. The passband of G-CLEF is broad, extending from 3500 angstrom to . This passband provides good sensitivity at blue wavelengths for stellar abundance studies and deep red response for observations of high-redshift phenomena. The design of G-CLEF incorporates several novel technical innovations. We give an overview of the innovative features of the current design. G-CLEF will be the first PRV spectrograph to have a composite optical bench so as to exploit that material's extremely low coefficient of thermal expansion, high in-plane thermal conductivity and high stiffness-to-mass ratio. The spectrograph camera subsystem is divided into a red and a blue channel, split by a dichroic, so there are two independent refractive spectrograph cameras. The control system software is being developed in model-driven software context that has been adopted globally by the GMT. G-CLEF has been conceived and designed within a strict systems engineering framework. As a part of this process, we have developed a analytical toolset to assess the predicted performance of G-CLEF as it has evolved through design phases.

Det är ofta användbart att beräkna eller uppskatta kapaciteter för olika parametrar och mängder. Det kan vara till exempel vid hantering av sobolevfunktioner eller vid undersökning av partiella dierentialekvationer. För ringområden i det vanliga rummet går detta att göra exakt, men för att kunna uppskatta kapacitet i viktade rum behöver man fyra exponentmängder Q, S, Q och S till hjälp. Med dessa kan man i princip redogöra för beteendet hos kapaciteten av olika ringområden kring en x punkt. Det nns många möjliga kombinationer av hur de fyra exponentmängderna kan se ut, men det är oklart precis vilka kombinationer som är möjliga. Genom att ta fram nya exempel på kombinationer av mängderna kan vi få större kännedom om vilka kombinationer som är möjliga, och på så sätt kunna dra större nytta av dem. För att hitta nya sammansättningar utgår vi från önskade exponentmängder och undersöker om det går att ta fram bakomliggande vikter som genererar dem. Sedan tidigare nns nio exempel på kombinationer av exponentmängder. Dessa skiljer sig åt vad gäller längden på intervallen som utgör dem och om ändpunkterna tillhör intervallen eller ej. I den här rapporten har tre nya exempel på kombinationer av exponentmängder tagits fram. I alla tre exempel skiljer sig Q och S bara i ändpunkten, och vi har visat att det är möjligt att konstruera ett exempel där alla fyra mängder delar ändpunkt, men där alla mängder utom S är öppna. / It is often useful to calculate or estimate capacities for dierent parameters and sets. This is the case for example when working with Sobolev functions or when studying partial dierential equations. For annuli i Rn this can be done exactly, but when estimating capacity in weighted spaces you need four exponent sets Q, S, Q and S. With these sets it is possible to describe how the capacity of dierent annuli around a given point behaves. There are many possible combinations of the four exponent sets, and it is not clear which combinations are possible. By generating new examples of combinations of the exponent sets we obtain a larger understanding of which combinations are possible, and are thus able to use them more eciently. To nd new examples we start from the desired exponent sets and investigate if one can produce an underlying weight that generates them. Earlier, there were nine examples of combinations of exponent sets. These dier in terms of the length of the intervals that constitute them and whether the endpoints belong to the sets or not. In this thesis three new examples of combinations of exponent sets have been constructed. In all three of them, Q and S dier only in the endpoint, and we have shown that it is possible to construct an example where all four sets share the same endpoint, but all sets except S are open.

Fixed bed reactors are widely applicable in a range of chemical process industries. Their ease of use and simplified operation make them an attractive and preferred option in reactor selection, however the geometric complexities within the bed as a result of the unstructured packing has made the design of such beds historically based on pseudo-homogenous models together with correlation-based transport parameters. Low tube-to-particle diameter ratio (N) beds, in particular, are selected for highly exothermic or endothermic reactions, such as in methane steam reforming or alkane dehydrogenation. Due to the large fraction of tube to catalyst particle contact in these low N beds, wall effects induce a mass transfer boundary layer at the wall, and in the case of thermal beds, a simultaneous resistance to heat transfer. Computational Fluid Dynamics (CFD) has been shown to be an accurate tool for experimental validation and predictive analysis of packed beds, and may be used to derive more accurate design parameters for fixed bed reactors. More specifically, the elucidation of dispersion, or the transport of reactant and product within the bed due to molecular diffusion and convective flow is of fundamental interest to the design of fixed beds. Computational Fluid Dynamics was used in this research to study solute dispersion in eight beds of varying N at a range of particle Reynolds numbers in the laminar flow regime. In the first stage of research, flow development was simulated in three-dimensional packed beds of spheres. Then, the reactor wall was sectioned to include a boundary condition of pure methane, from which the solute could laterally disperse into the bed. In the second stage, a two-dimensional representation of the bed was created using the commercial Finite Element Analysis software COMSOL Multiphysics. In these models, axial velocity profiles and radial methane concentration profiles taken from the 3-D models were supplied, and a fitting procedure by use of the Levenberg-Marquardt Least-Squares optimization algorithm was completed to fit radial dispersion coefficients and near-wall mass transfer coefficients to the CFD data. These optimization runs were conducted for all N at a number of bed depths in each case. Two sub-studies were conducted in which a constant velocity profile and a local velocity profile were supplied to the 2-D model, and the optimization re-run. It was found that this two parameter model did not fully account for various mechanisms of dispersion in the bed, namely the increasing rate of dispersion from the tube wall boundary layer up to the bed center, but only accounted for a diffusive-dispersion at the wall and a constant-rate, convective-dispersion everywhere else in the bed. Length dependency of dispersion coefficients were also noted, particularly in the developing sections of the bed. Nevertheless, the combined CFD and optimization procedure proved to be an accurate and time-efficient procedure for the derivation of dispersion coefficients, which may then lend themselves to the standard design of packed bed reactors.

Fixed bed reactors are widely applicable in a range of chemical process industries. Their ease of use and simplified operation make them an attractive and preferred option in reactor selection, however the geometric complexities within the bed as a result of the unstructured packing has made the design of such beds historically based on pseudo-homogenous models together with correlation-based transport parameters. Low tube-to-particle diameter ratio (N) beds, in particular, are selected for highly exothermic or endothermic reactions, such as in methane steam reforming or alkane dehydrogenation. Due to the large fraction of tube to catalyst particle contact in these low N beds, wall effects induce a mass transfer boundary layer at the wall, and in the case of thermal beds, a simultaneous resistance to heat transfer. Computational Fluid Dynamics (CFD) has been shown to be an accurate tool for experimental validation and predictive analysis of packed beds, and may be used to derive more accurate design parameters for fixed bed reactors. More specifically, the elucidation of dispersion, or the transport of reactant and product within the bed due to molecular diffusion and convective flow is of fundamental interest to the design of fixed beds. Computational Fluid Dynamics was used in this research to study solute dispersion in eight beds of varying N at a range of particle Reynolds numbers in the laminar flow regime. In the first stage of research, flow development was simulated in three-dimensional packed beds of spheres. Then, the reactor wall was sectioned to include a boundary condition of pure methane, from which the solute could laterally disperse into the bed. In the second stage, a two-dimensional representation of the bed was created using the commercial Finite Element Analysis software COMSOL Multiphysics. In these models, axial velocity profiles and radial methane concentration profiles taken from the 3-D models were supplied, and a fitting procedure by use of the Levenberg-Marquardt Least-Squares optimization algorithm was completed to fit radial dispersion coefficients and near-wall mass transfer coefficients to the CFD data. These optimization runs were conducted for all N at a number of bed depths in each case. Two sub-studies were conducted in which a constant velocity profile and a local velocity profile were supplied to the 2-D model, and the optimization re-run. It was found that this two parameter model did not fully account for various mechanisms of dispersion in the bed, namely the increasing rate of dispersion from the tube wall boundary layer up to the bed center, but only accounted for a diffusive-dispersion at the wall and a constant-rate, convective-dispersion everywhere else in the bed. Length dependency of dispersion coefficients were also noted, particularly in the developing sections of the bed. Nevertheless, the combined CFD and optimization procedure proved to be an accurate and time-efficient procedure for the derivation of dispersion coefficients, which may then lend themselves to the standard design of packed bed reactors.

Le mémoire traite de la machine à réluctance variable en proposant d'une manière simultanée et du point de vue conception des solutions à ses deux inconvénients majeurs à savoir les ondulations de couple et les efforts radiaux. Les premières se propagent le long de la chaine de transmission diminuant ainsi le confort des usagers et les deuxièmes sont à l’origine d’une nuisance sonore. Dans une première partie et en s’intéressant à une structure axiale caractérisée par une faible force radiale, un bilan sur cette structure est donc établi. En effet, une configuration à deux stators et un rotor est la plus adéquate pour éventuellement remplacer la machine radiale de référence. Cette structure axiale est comparée à cette machine de référence après avoir établi des règles de passage d’une structure à une autre. Un premier passage est effectué en gardant le même encombrement et un deuxième passage en dimensionnant la machine axiale pour satisfaire le même cahier des charges que la machine radiale. Dans une deuxième partie, le travail s’oriente vers la modification de la structure radiale de la machine de référence et son optimisation. Plusieurs modifications sont proposées dont une structure avec une cale magnétique qui est la plus performante. Des optimisations géométriques à l’aide de l’algorithme génétique sur un point de fonctionnement sont ensuite effectuées pour remédier aux deux problèmes. A la fin, un récapitulatif de plusieurs structures optimisées est proposé pour servir de référence. Le choix de la machine la plus adéquate pourra donc être effectué en faisant un compromis entre la maximisation du couple, la réduction de ses ondulations et la réduction des efforts radiaux. / This report deals with switched reluctance motor by offering design solutions to the drawbacks of torque ripples and radial forces in the same time. Torque ripples reduce the user comfort and radial forces are the origin of noise. In the first part, an axial structure characterized by low radial force is analysed. Indeed, an axial configuration with two stators and one rotor is the most appropriate to replace the reference radial machine. Ones the rules of passage from one structure to another are established, the axial structure is then compared to the reference one. A first passage is made by keeping the same volume and a second one by sizing the axial machine with the same specifications as the radial one. In the second part, the work concerns the modification of radial structure of the reference machine and its optimization. Several modifications are proposed including a structure with a magnetic wedge which is the most efficient. Geometric optimization using genetic algorithm are then performed on operating points to remedy the both problems. In the end, several optimized structures are proposed. The choice of the most suitable machine can be done by making a compromise between the torque maximization, reducing its ripples and reducing radial forces.

O desgaste e a vida útil dos componentes mecânicos é uma questão de grande interesse econômico e tecnológico, devido suas diversas aplicações. Estudos tribológicos recentes apresentam novas soluções para esta questão, como a texturização superficial a laser, cujo o propósito é aumentar a eficiência do processo de lubrificação nestes componentes. Este trabalho analisa, por meio de um modelo teórico, os efeitos desta textura superficial no processo de lubrificação hidrodinâmico em mancais radiais. Este modelo é elaborado a partir da equação de Reynolds, cuja solução representa o campo de pressão no fluido lubrificante, determinando assim o escoamento deste em mancais radiais. A solução desta equação foi obtida através de um algoritmo desenvolvido no software Maple, utilizando o método de diferenças finitas. A partir deste campo de pressão, determina-se a capacidade de carga do mancal, definida como um parâmetro de qualidade da lubrificação, afinal, quanto maior for a capacidade de carga melhor será o processo lubrificação. Através de simulações computacionais, foram determinadas as dimensões, densidade superficial e forma das microcavidades que maximizam a capacidade de carga, aprimorando desta maneira o processo de lubrificação e estabelecendo um padrão ideal de textura superficial para o mancal. Convém ressaltar que. nestas simulações. a análise de cada uma das características das micro-cavidades foram realizadas variando-se os parâmetros (no algoritmo) relacionados a elas, como foi proposto pelo modelo teórico / The wear and the shelf life of mechanical components are a question of great economic and technological interest. had its diverse applications. Recent tribologics studies show new solutions for this question, as the laser surface texturing, whose the intention is to increase the efficiency of the lubrication process in these components. This work analyzes, means of a theoretical model, the effect of this surface textured in the hydrodynamic process of lubrication in journal bearings. This model is developed from the equation of Reynolds, whose solution represents the pressure distribution in the lubricant fluid, then determining the draining of this in journal bearings. The solution of this equation was gotten by means of an algorithm developed in the Maple software, using the finite difference methods. From this pressure distribution, the load capacity of the journal bearing is determined, defined as a quality parameter of the lubrication, after all, how much bigger will be the load capacity better will be the lubrication process Means of computational simulations had been determined, the measures, surface density and shape of the micro−holes that maximize the load capacity, improving in this way the lubrication process and set out an ideal standard of surface texture to the bearing. Is important stand out that, in these simulations, the analysis of each characteristic of the micro−holes was carried through varying parameters (in the algorithm) related to these, as was considered by the theoretical model

In this master thesis methods for increasing temporal resolution when reconstructing radially sampled MRI data have been developed and evaluated. This has been done in two steps; first the order in which data is sampled in k-space has been optimized, and second; temporal filters have been developed in order to utilize the high sampling density in central regions of k-space as a result of the polar sampling geometry to increase temporal resolution while maintaining image quality.By properly designing the temporal filters the temporal resolution is increased by a factor 3–20 depending on other variables such as imageresolution and the size of the time varying areas in the image. The results are obtained from simulated raw data and subsequent reconstruction. The next step should be to acquire and reconstruct raw data to confirm the results. / This Master thesis work were performed at Dept. Radiation Physis, Linköping University, but examined at Dept. Radiation Physics, Umeå University

Made available in DSpace on 2015-04-14T13:58:29Z (GMT). No. of bitstreams: 1 410347.pdf: 7538820 bytes, checksum: 53e9a59ec6b95d7b6b4d50b4bfd6787b (MD5) Previous issue date: 2008-12-05 / Consolida??o por Constri??o Radial (CCR) ? uma t?cnica de metalurgia do p? que possibilita a obten??o de pe?as met?licas near-net-shape, com alta densidade e de formas complexas a custos de produ??o mais baixos do que as tecnologias convencionais. CCR se assemelha em alguns aspectos ao processo de compacta??o isost?tica a quente, sendo que as principais diferen?as s?o que o processo CCR utiliza moldes cer?micos fabricados a partir do processo de microfus?o e usa um meio compressor secund?rio na forma de p?, ambos confinados em um container. Neste trabalho desenvolveu-se um sistema experimental de CCR visando ? produ??o de pr?-formas de ferro de alta densidade. Como meios compressores secund?rios foram utilizados p? de ferro, p? de alumina calcinada e p? cer?mico (argila calcinada). As pr?-formas produzidas foram caracterizadas quanto ? densidade, microestrutura e dureza. Dos meios compressores secund?rios testados, o p? cer?mico (argila calcinada) mostrou-se com maior potencial de utiliza??o. Observou-se que a configura??o do container/meio compressor secund?rio/molde cer?mico influencia substancialmente nas caracter?sticas de densidade e dimensionais das pr?-formas. A microestrutura das pr?-formas produzidas mostrou que houve uma consolida??o satisfat?ria do p?. Observou-se tamb?m uma boa correla??o entre dureza e densidade. Os par?metros de processo que proporcionaram obter os melhores resultados em termos de densidade e caracter?sticas dimensionais foram: press?o de compacta??o de aproximadamente 400 MPa, temperatura de aquecimento de 1120?C, configura??o do container met?lico/meio compressor secund?rio/molde cer?mico de forma a evitar a presen?a de meio compressor secund?rio na parte inferior do molde cer?mico e uso de matriz met?lica para o confinamento do container a fim de evitar a deforma??o pl?stica lateral do mesmo a altas press?es e temperatura

INTRODUÇÃO: A utilização de enxertos arteriais na revascularização cirúrgica do miocárdio já está bem estabelecida atualmente pelos cirurgiões cardiovasculares, e sua esqueletização tem apresentado algumas vantagens, a princípio com a artéria torácica interna esquerda. OBJETIVO: Com o objetivo de analisar esse método de dissecção na artéria radial, foram avaliados os desempenhos funcional e hemodinâmico bem como as características morfoanatômicas e histológicas dos enxertos aortocoronários de artéria radial, esqueletizados ou com tecidos adjacentes, na revascularização cirúrgica do miocárdio. MÉTODOS: Foram comparados 40 pacientes, distribuídos randomicamente em dois grupos. No grupo I foi utilizada artéria radial esqueletizada (20 pacientes) e no grupo II, artéria radial com tecidos adjacentes (20 pacientes), para os ramos marginais da artéria coronária esquerda. No total, 39 pacientes foram submetidos a cinecoronariografia e fluxometria com cateter-guia Doppler de 12 MHz (0,014 polegada, Flowire, Jometrics Inc.), no pós-operatório imediato. RESULTADOS: Os dois grupos apresentaram características demográficas semelhantes. As variáveis intra-operatórias principais da artéria radial também foram semelhantes, com comprimento de 17,1 cm no grupo I e de 16,3 cm no grupo II, e débito livre de 80,3 ml/min no grupo I e de 95,5 ml/min no grupo II. Não foram observadas diferenças morfoanatômicas e histológicas nos grupos comparados. Os diâmetros dos enxertos de artéria radial, calculados por meio de angiografia quantitativa no pós-operatório, foram semelhantes (2,66 mm no grupo I e 2,53 mm no grupo II), assim como as variáveis fluxométricas (fluxo sanguíneo de 54,9 ml/min no grupo I e de 44,28 ml/min no grupo II, e reserva de fluxo de 2,12 no grupo I e de 2 no grupo II). Por outro lado, a cinecoronariografia revelou presença de oclusão em um enxerto e estenose em cinco enxertos no grupo II, enquanto o grupo I apresentou estenose em apenas um enxerto de artéria radial (p = 0,091). CONCLUSÕES: Os enxertos aortocoronários de artéria radial tiveram bom desempenho funcional e hemodinâmico precoce. Não houve diferença entre os grupos quanto ao desempenho funcional e hemodinâmico precoce, e quanto às características morfoanatômicas e histológicas. / BACKGROUND: The use of artery grafts in the surgical revascularization of the myocardium is currently a well-established procedure by cardiovascular surgeons, and its skeletonization has posed some advantages, in principle, with the left internal thoracic artery. OBJECTIVE: With the purpose of analyzing this radial artery harvest method, the study evaluated the functional and hemodynamic early performance, as well as the morphological anatomic and histological features of the aortic coronary grafts of the radial artery, skeletonized or with surrounding tissues, in the surgical revascularization of the myocardium. METHODS: The study compared 40 patients, randomly distributed in two groups. In Group I, we employed a skeletonized radial artery (20 patients), and in Group II, the radial artery with surrounding tissues (20 patients), for the marginal branches of the left coronary artery. In total, 39 patients underwent cinecoronariography and fluxometry with a 12-MHz Doppler guide catheter (0.014 in., Flowire, Jometrics Inc.), in the immediate postoperative period. RESULTS: Both groups presented similar demographic features. The main intra-surgical variables of the radial artery were also similar, with an extension of 17.1 cm in Group I, and 16.3 cm in Group II, and the free flow was of 80.3 ml/min in Group I, and of 95.5 ml/min in Group II. No morphological anatomic and histological differences were observed in the compared groups. The diameters of the radial artery grafts, which were calculated by quantitative angiography in the postoperative period, were similar (2.66 mm in Group I, and 2.53 mm in Group II), as well as the flow variables (blood flow of 54.9 ml/min in Group I, and of 44.28 ml/min in Group II, and a flow reserve of 2.12 in Group I, and of 2 in Group II). On the other hand, the cinecoronariography revealed the presence of an occlusion in one graft, and of stenosis in five grafts of Group II, while Group I presented stenosis in only one radial artery graft (p = 0.091). CONCLUSIONS: The aortic coronary grafts of the radial artery displayed good functional and hemodynamic early performance. There was no difference between the groups regarding functional and hemodynamic early performance, and the morphological anatomical and histological features.

La presente tesis es un estudio sobre la alternancia de código entre el castellano y el shipibo-konibo en programas radiales conducidos por locutores shipibos. En el capítulo 1, se expone el propósito de la investigación, la metodología que se empleó y la estructura de la tesis. En el capítulo 2, se exponen, en primer lugar, algunos datos actuales de la lengua shipibo-konibo; luego se ofrece un resumen de algunos de los trabajos anteriores sobre la alternancia de código y se desarrolla el Modelo de la Marcación de Myers- Scotton; por último, se realiza una revisión de los trabajos de la alternancia de código en los medios de comunicación. El capítulo 3 se dedica a los factores extralingüísticos de la alternancia de código entre castellano y shipibo-konibo en los programas radiales shipibos. Por un lado, se describe a los participantes del evento comunicativo estudiado (los locutores y la audiencia); por otro lado, se presta atención al género periodístico y a la estructura de las secciones de los programas. En el capítulo 4, se analiza la frecuencia de distribución del uso de ambas lenguas (castellano y shipibo-konibo) en términos de número de palabras. Nuestro estudio demuestra que los locutores emiten un discurso con un 77% de términos castellanos frente a un 23% de palabras shipibo-konibo. Esto es muy interesante, puesto que se trata de programas periodísticos que forman parte de lo que se conoce como “radio shipiba”. Ante esto, nos preguntamos cuál es la función de ese 23% de términos shipibo-konibo y proponemos que dicha función es la de “shipibizar” un discurso que, de otra forma, transcurriría totalmente en castellano. El fenómeno que entendemos aquí como “shipibización” resulta sumamente interesante desde la perspectiva de los estudios de alternancia de código y gran parte de nuestro estudio se enfoca en él. Se demostrará que la “shipibización” se basa principalmente en el uso de inserciones de determinantes y vocativos en la lengua shipibo-konibo en el discurso castellano. En el capítulo 5, se concluye que estos fragmentos shipibo-konibo se usan como estrategia discursiva destinada a proyectar un vínculo de identidad étnica con su audiencia. A partir de ello, se postula un rasgo solidario, que va más allá de aspectos puramente lingüísticos o estructurales y que se basa en la explotación de la alternancia como recurso socio-pragmático de pertenencia grupal. / Tesis