Ce mémoire présente un résumé de mon travail de chercheur en théorie de la matière condensée. Je présente tout d'abord mon travail de doctorat sur un modèle du supraconducteur à haute température critique Y Ba2Cu3O7. Je décris aussi les calculs de la profondeur de pénétration du champ magnétique, motivés par des expériences, dans le cadre de la théorie de couplage fort électron-phonon d'Eliashberg. La deuxième partie est consacrée aux travaux effectués lors de mon séjour postdoctoral sur la durée de vie d'une quasiparticule dans une boîte quantique. Puis j'aborde le sujet des atomes ultra-froids : modes collectifs et transition BEC-BCS. A cette occasion sont entre autres présentés mes travaux sur les problèmes à trois et quatre corps en mécanique quantique, ainsi que l'équation d'état d'un condensat de bosons composites. Je passe ensuite à mes travaux sur les excitons et le calcul de bruit de courant à travers un point quantique. Enfin, je présente mes projets de recherche.

Au cours de ce travail de doctorat, j'ai participé au montage complet d'une expérience visant à refroidir et manipuler deux espèces atomiques alcalines fermioniques, 6Li et 40K. Le dispositif expérimental a pour objectifs l'étude des mélanges de fermions ultra-froids de masses différentes et la réalisation d'un simulateur analogique quantique flexible. En effet, là où certains problèmes quantiques à N corps en interaction, comme la supraconductivité à haute température critique ou l'antiferromagnétisme frustré, sont difficiles à aborder analytiquement et numériquement, les atomes froids, systèmes purs et contrôlables jusque dans leur interaction, offrent un point de vue complémentaire intéressant. Lors de la conception du dispositif expérimental, nous avons assemblé une enceinte à ultra-vide, réalisé un système laser stabilisé complet pour chaque espèce et mis en place deux sources atomiques performantes, un ralentisseur Zeeman de 6Li et un piège magnéto-optique bidimensionnel de 40K; la plupart des grandeurs optiques et électriques ainsi que les diagnostiques d'imagerie étant contrôlés par voie informatique. Ces premières étapes ont permis l'obtention d'un piège magnéto-optique à deux espèces performant, contenant typiquement 5x10^9 atomes de 6Li et 8x10^9 atomes de 40K. Dans cette configuration, nous avons produit les premières molécules hétéronucléaires de 6Li40K* par photoassociation, pour lesquelles nous avons observé et identifié 70 raies rovibrationnelles. Dans une seconde partie, je décris en détail le transport magnétique du mélange atomique entre la cellule du piège magnéto-optique et une cellule d'expérience, où règne un vide poussé et bénéficiant d'un grand accès optique. Ce dispositif complet, de sa conception à son optimisation expérimentale, en passant par son assemblage mécanique et la mise en place du programme de contrôle et des diagnostiques numériques, constitue le coeur de mon travail. Son efficacité a pu être testée et optimisée, permettant ainsi un transfert performant du mélange vers la cellule finale. Aussi, à l'issue de cette thèse, tous les outils sont opérationnels pour poursuivre le refroidissement du mélange par évaporation dans un piège magnétique, et par conséquent le champ est ouvert pour la simulation quantique et la compréhension de problèmes à N corps dans les mélanges de gaz de Fermi ultra-froids.

Cette thèse traite du problème à N+1 corps dans les gaz de fermions ultrafroids fortement polarisés. Il s'agit de la situation où un unique atome d'une espèce de spin est immergé dans une mer de Fermi d'atomes de l'autre espèce.<br /> <br /> La première partie utilise une approche hamiltonienne basée sur un développement général de la fonction d'onde du système faisant intervenir un nombre arbitraire de paires particule-trou. Nous montrons que la série d'approximations successives construite converge très rapidement et nous obtenons ainsi une solution essentiellement exacte pour l'énergie et la masse effective du polaron. En dimension 1, dans deux cas particuliers, ce problème peut être résolu analytiquement. La comparaison avec notre série d'approximations est excellente et confirme l'efficacité de ce développement. Enfin, nous précisons les différents cas limites, ainsi que l'influence du rapport des masses entre les deux espèces de spin.<br /> <br /> Dans une deuxième partie, nous utilisons le formalisme des diagrammes de Feynman pour décrire à la fois le polaron et l'état lié. Pour le polaron, nous construisons une théorie équivalente à l'approche hamiltonienne. Pour l'état lié, nous obtenons à nouveau une série d'approximations dont la convergence très rapide vers la solution exacte est parfaitement comprise. Cette approche nous fournit donc une solution quasi-exacte au problème tout au long de la transition BEC-BCS. Enfin, en comparant les énergies des deux quasi-particules, nous étudions la position de la transition polaron - état lié.

Ultracold Fermi gas is an exciting field benefiting from atomic physics, optical physics and condensed matter physics. It covers many aspects of quantum mechanics. Here I introduce some of my work during my graduate study. We proposed an optical spectroscopic method based on electromagnetically-induced transparency (EIT) as a generic probing tool that provides valuable insights into the nature of Fermi paring in ultracold Fermi gases of two hyperfine states. This technique has the capability of allowing spectroscopic response to be determined in a nearly non-destructive manner and the whole spectrum may be obtained by scanning the probe laser frequency faster than the lifetime of the sample without re-preparing the atomic sample repeatedly. Both quasiparticle picture and pseudogap picture are constructed to facilitate the physical explanation of the pairing signature in the EIT spectra. Motivated by the prospect of realizing a Fermi gas of 40 K atoms with a synthetic non-Abelian gauge field, we investigated theoretically BEC-HCS crossover physics in the presence of a Rashba spin-orbit coupling in a system of two-component Fermi gas with and without a Zeeman field that breaks the population balance. A new bound state (Rashba pair) emerges because of the spin-orbit interaction. We studied the properties of Rashba pairs using a standard pair fluctuation theory. As the two-fold spin degeneracy is lifted by spin-orbit interaction, bound pairs with mixed singlet and triplet pairings (referred to as rashbons) emerge, leading to an anisotropic superfluid. We discussed in detail the experimental signatures for observing the condensation of Rashba pairs by calculating various physical observables which characterize the properties of the system and can be measured in experiment. The role of impurities as experimental probes in the detection of quantum material properties is well appreciated. Here we studied the effect of a single classical impurity in trapped ultracold Fermi superfluids. Although a non-magnetic impurity does not change macroscopic properties of s-wave Fermi superfluids, depending on its shape and strength, a magnetic impurity can induce single or multiple mid-gap bound states. The multiple mid-gap states could coincide with the development of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase within the superfluid. As an analog of the Scanning Tunneling Microscope, we proposed a modified radio frequency spectroscopic method to measure the focal density of states which can be employed to detect these states and other quantum phases of cold atoms. A key result of our self consistent Bogoliubov-de Gennes calculations is that a magnetic impurity can controllably induce an FFLO state at currently accessible experimental parameters.

Modification of black cotton soils by chemical admixtures is a common method for stabilizing the swell-shrink tendency of expansive soils. Advantages of chemical stabilization are that they reduce the swell-shrink tendency of the expansive soils and also render the soils less plastic. Among the chemical stabilization methods for expansive soils, lime stabilization is most widely adopted method for improving the swell-shrink characteristics of expansive soils. Lime stabilization of clays in field is achieved by shallow mixing of lime and soil or by deep stabilization technique. Shallow stabilization involves scarifying the soil to the required depth and lime in powder or slurry form is spread and mixed with the soil using a rotovator. The use of lime as deep stabilizer has been mainly restricted to improve the engineering behaviour of soft clays Deep stabilization using lime can be divided in three main groups: lime columns, lime piles and lime slurry injection. Lime columns refer to creation of deep vertical columns of lime stabilized material. Lime piles are usually holes in the ground filled with lime. Lime slurry pressure injection, as the name suggests, involves the introduction of a lime slurry into the ground under pressure. Literature review brings out that lime stabilization of expansive clays in field is mainly performed by mixing of lime and soil up to shallow depths. The use of lime as deep stabilizer has been mainly restricted to improve the engineering behaviour of soft clays. Use of lime in deep stabilization of expansive soils however has not been given due attention. There exists a definite need to examine methods for deep stabilization of expansive soils to prevent the deeper soil layers from causing distress to the structures in response to the seasonal climatic variations. In addition, there exists a need for in-situ soil stabilization using lime in case of distressed structures founded on expansive soil deposits. The physical mixing of lime and soil in shallow stabilization method ensures efficient contact between lime and clay particles of the soil. It however has limitation in terms of application as it is only suited for stabilization of expansive soils to relatively shallow depths. Studies available have not compared the relative efficiency of the lime pile technique and lime-soil mixing method in altering the physico-chemical, index and engineering properties of expansive black cotton soils. To achieve the above objectives laboratory experiments are performed that study: 1. the efficacy of lime piles in stabilizing compacted black cotton soil specimens from Chitradurga District in Karnataka. The efficiency of lime piles in chemically stabilizing the compacted black cotton soil mass was investigated as a function of: a)amount of lime contained in the lime pile b)radial migration of lime from the central lime pile c)migration of lime as a function of soil depth 2. the relative impact of the lime pile technique and lime-soil mixing method in altering the physico-chemical, index and engineering properties of expansive black cotton soil. The organization of this thesis is as follows After the first introductory chapter, a detailed review of literature performed towards highlighting the need to examine stabilization of expansive soils using lime pile technique is brought out in Chapter 2. Chapter 3 presents a detailed experimental programme of the study. 25 mm and 75 mm diameter lime piles were installed in the compacted soil mass to study the influence of amount of lime contained in the lime pile on the soil properties. The amount of quick lime contained in the 25 mm and 75 mm lime piles corresponded to 1 % and 3 % by dry weight of the soil mass respectively. Radial and vertical migration of lime from the central lime pile was examined by sampling soil specimens at different radial distances from the central lime pile and at different depths of soil sample. At a given depth and radial distance, migration of lime was estimated by comparing the exchangeable cation composition, pH and pore salinity of the treated soil with that of the natural (untreated) black cotton soil specimen. Alterations in the soil engineering properties at a given depth and radial distance were evaluated by comparing the index properties, swell potential and unconfined compressive strength of the lime pile treated soil specimen with those of the untreated specimen. To compare the relative efficiency of lime mixing and lime pile technique in altering the swelling behaviour of black cotton soil, batches of black cotton soil specimens were treated with 1 % and 3 % quick lime on dry soil weight basis. The compacted soil-lime mixes were cured at moisture contents of 31-34 % for a period of 10 days. The physico-chemical, index and engineering properties of the 1 % lime mixed specimens are compared with those of the 25 mm lime pile treated specimens. The properties of the 3 % lime mixed soil specimens are compared with those of the 75 mm lime pile treated specimens. Chapter 4 examines the efficacy of lime piles in stabilizing compacted black cotton soil specimens from Chitradurga District in Karnataka. Experimental results showed that controlling the swell potential of deep expansive soil deposits is possible by the lime pile technique. Treatment with lime pile caused migration of dissociated calcium and hydroxyl ions into the surrounding soil mass. In case of 25 mm lime pile, the experimental setup allowed measurement of migration of lime up to three times the lime pile diameter. In case of 75 mm lime pile, the experimental setup allowed measurement of migration of lime up to 1.6 times pile diameter. In both experiments, migration of lime was also uniform through out the soil depth of 280 mm. Migration of calcium and hydroxyl ions increased the pore salinity and pH of the treated soil mass. The increase in pH caused clustering of additional exchangeable calcium ions at the negative clay particle edges. The increased pore salinity and exchangeable calcium ions reduced the diffuse ion layer thickness that in turn suppressed the plasticity index and the swell potential of the compacted expansive soil. The laboratory results hence bring out that lime pile treatment in the field can substantially reduce the swell potential of the soil at least to a radial extent of 2 to 3 times the lime pile diameter. The 75 mm lime pile contained lime content in excess of the initial consumption of lime (ICL) value of the black cotton soil - namely 2.6 %. Laboratory results showed that migration of hydroxyl ions even from the 75 mm pile could not elevate the soil pH to levels required for soil-lime pozzoIonic reactions (pH ≥12). The very low solubility of lime in water (< 1 g/litre) and the impervious nature of the black cotton soil are considered to have impeded efficient interactions between lime and soil in course of treatment of the expansive soil with lime piles. Absence of soil-lime pozzolonic reactions precluded the formation of cementation compounds in the lime pile treated soil specimens. Cementation compounds formed by the soil-lime pozzolonic reactions are responsible for the much higher strengths of lime stabilized soils. Consequently, treatment with 25 mm pile had no impact on the unconfined compressive strength of the black cotton soil. Comparatively, treatment with 75 mm lime pile slightly increased the strength of the treated soil due to increased inter-particle attraction and particle flocculation. Chapter 5 compares the relative efficiency of the lime pile technique and lime-soil mixing method in altering the physico-chemical, index and engineering properties of expansive black cotton soil. Experimental results showed that mixing of soil and lime promote stronger chemical interactions between lime released hydroxyl ions and clay particles than that achieved by diffusion of lime from a central lime pile. The more alkaline pH of the lime mixed soil specimens rendered the clay particle edges more negative. Consequently, more calcium ions were adsorbed at the clay particle edges of the lime mixed soil specimens imparting them higher exchangeable calcium contents than the lime pile treated soil specimens. Also, at 3 % lime addition, the pH of the lime-mixed soil was sufficiently high (in excess of 12) to cause dissolution of silica and alumina from the clay lattice necessary for the formation of cementation compounds. The stronger lime modification reactions plus the lime-soil pozzolonic reactions (applicable for soil treated with lime content greater than ICL value) achieved by the lime mixing technique rendered the expansive soil much less plastic, much less expansive and much stronger than the lime pile treated specimens. The results of the laboratory study hence suggest that if a choice exists in the field between conventional method of spreading-mixing-compacting of soil-lime mixes and treating the ground with lime piles, the former technique should be adopted because of its greater efficacy in stabilizing the expansive soil. Chapter 6 summarizes the findings of the study.

Submitted by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-03-28T22:17:06Z No. of bitstreams: 1 AllisonCC_DISSERT.pdf: 23495470 bytes, checksum: 71481acfb5946c94f60433199d92a734 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T16:53:38Z (GMT) No. of bitstreams: 1 AllisonCC_DISSERT.pdf: 23495470 bytes, checksum: 71481acfb5946c94f60433199d92a734 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T17:02:20Z (GMT) No. of bitstreams: 1 AllisonCC_DISSERT.pdf: 23495470 bytes, checksum: 71481acfb5946c94f60433199d92a734 (MD5) / Made available in DSpace on 2018-06-18T17:02:29Z (GMT). No. of bitstreams: 1 AllisonCC_DISSERT.pdf: 23495470 bytes, checksum: 71481acfb5946c94f60433199d92a734 (MD5) Previous issue date: 2017-08-28 / The reduction of power consumption and operational costs in petroleum industry has become an increasingly concernment in the last years. Due to that the search for new petroleum production methods and the use of process controlling techniques integrated to its artificial lift systems for optimizing that process plays a main role, and the development of well pump controllers is the main study object. The work proposes the implementation of a control system for oil wells equipped with ESP (Electrical Submersible Pumping), having as main methodology the use of the Arduino® Platform. The desired result is the development of a low cost oil pump controller system, with software technology which brings easy configuration and remote operation, and validation of its use in a real oil well. The main goals are the cost reduction through the use of inexpensive hardware, and the the increase of developing speed by migrating to a higher level programming language, both compared to current well pumping controller solutions, based on use of PLC (Programmable Logic Controller). Other than that, the proposal represents a big step for the dissemination of open hardware philosophy for the petroleum production process control, opening doors for incoming implementation of new controllers for other artificial lift methods / A redução de consumo energético e do custo operacional na indústria de petróleo vem se tornando uma preocupação cada vez maior ao longo dos últimos anos. Nesse contexto a busca por novos métodos de produção de petróleo e a utilização de técnicas de controle integradas aos sistemas de elevação artificial para a otimização desse processo exercem um importante papel, e o desenvolvimento de controladores de bombeio é o principal objeto de estudo. O trabalho propõe a implementação de um sistema de controle para poços equipados com BCS (Bombeio Centrífugo Submerso), tendo como metodologia base o uso da plataforma Arduino®. O resultado desejado é o desenvolvimento de um sistema de controle de bombeio de baixo custo, com tecnologia de software que contemple fácil configuração e operação remota, e a validação do seu uso em um poço produtor de petróleo real. Os objetivos principais são a redução de custos através da utilização de hardware mais econômico, e a aceleração do desenvolvimento devida à migração para uma linguagem de programação de mais alto nível, ambos em relação às soluções de controle de bombeio atuais, baseadas no uso de CLP (Controlador Lógico Programável). Além disso, a proposta representa um grande passo para a disseminação do uso da filosofia de hardware livre para controle do processo de produção de petróleo, abrindo portas para a implementação de novos controladores para outros métodos de elevação / 2018-03-28

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-09T22:35:46Z No. of bitstreams: 1 EbertonDaSilvaMarinho_TESE.pdf: 27289302 bytes, checksum: afbb77aed251ffa31c13cdae992f063a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-13T21:12:47Z (GMT) No. of bitstreams: 1 EbertonDaSilvaMarinho_TESE.pdf: 27289302 bytes, checksum: afbb77aed251ffa31c13cdae992f063a (MD5) / Made available in DSpace on 2017-03-13T21:12:47Z (GMT). No. of bitstreams: 1 EbertonDaSilvaMarinho_TESE.pdf: 27289302 bytes, checksum: afbb77aed251ffa31c13cdae992f063a (MD5) Previous issue date: 2016-08-22 / O Compressive Sensing (CS) ? uma t?cnica de processamento de dados eficiente na recupera??o e constru??o de sinais a partir de uma taxa de amostragem menor que a requerida pelo teorema de Shannon-Nyquist. Esta t?cnica permite uma grande redu??o de dados para sinais que podem ser esparsamente representados. A Transformada Wavelet tem sido utilizada para comprimir e representar muitos sinais naturais, incluindo s?smicos, de uma forma esparsa. H? diversos algoritmos de reconstru??o de sinais que utilizam a t?cnica de CS, como por exemplo: o $\ell_1$-MAGIC, o Fast Bayesian Compressive Sensing (Fast BCS) e o Stagewise Orthogonal Matching Pursuit (StOMP). Esta tese compara a recupera??o de tra?os s?smicos sob uma perspectiva estat?stica usando diferentes m?todos do CS, transformadas wavelets e taxas de amostragens. Mediu-se a correla??o entre o Erro Relativo (ER) de recupera??o pelo CS e as medi??es: coeficiente de varia??o, assimetria, curtose e entropia do sinal original. Parece haver uma correla??o entre a curtose e entropia do sinal com o ER de reconstru??o pelo CS. Ademais, foi analizado a distribui??o do ER no CS. O $\ell_1$-MAGIC teve melhores resultados para taxas de amostragens at? 40%. Al?m disso, a distribui??o do ER no $\ell_1$-MAGIC teve mais histogramas normais, sim?tricos e mesoc?rticos que no Fast BCS. Entretanto, para taxas de amostragem acima de 50%, o Fast BCS mostrou um melhor desempenho em rela??o ? m?dia do ER.

A furosemida é um fármaco de ação diurética e amplamente utilizado em tratamentos de doenças renais, cardíacas e pulmonares. Sua absorção é problemática e de alta variabilidade inter e intraindividual. Este fármaco tem sido classificado como pertencente às classes II (baixa solubilidade e alta permeabilidade) ou IV (baixa permeabilidade e baixa solubilidade) do Sistema de Classificação de Biofarmacêutica (SCB). Em estudos anteriores da equipe de pesquisa, SPRICIGO e colaboradores (2008) e SILVA (2014) desenvolveram complexos de furosemida com hidroxipropil-&#946;-ciclodextrina que permitiram a otimização da solubilidade deste fármaco. Entretanto, dados sobre a sua permeabilidade intestinal, quando complexado, não foram determinados. Somando-se a isto, a literatura apresenta informações distintas em relação a este parâmetro, o que corrobora a importância de se avaliar a permeabilidade deste fármaco. Diversas técnicas têm sido empregadas para a avaliação da permeabilidade intestinal dos fármacos. No presente trabalho empregou-se o modelo de perfusão in situ de passagem tripla, cuja técnica possibilita avaliar a permeabilidade em três segmentos diferentes em um mesmo animal e ainda, apresenta características interessantes, pois trata-se de um método que proporciona, durante todo o experimento, condições mais próximas daquelas encontradas durante o processo in vivo de absorção de fármacos no intestino tais como: suprimento sanguíneo, inervação intacta, preservação das proteínas transportadoras de membranas e presença da camada de muco. O presente trabalho foi dividido nas seguintes etapas: (i) obtenção da furosemida complexada com hidroxipropil-&#946;-ciclodextrina, (ii) caracterização dos fármacos utilizando técnicas de análises térmicas, (iii) estudo de perfusão in situ de passagem tripla nos três segmentos intestinais (duodeno, jejuno e íleo) de ratos machos Wistar na ausência e na presença de inibidores da glicoproteína P e de enzimas metabolizadoras CYP3A4 com posterior análise estatística do impacto da ciclodextrina e inibidores na permeabilidade da furosemida e; (iv) análise histológica das microvilosidades intestinais após o ensaio de perfusão in situ nos três segmentos intestinais. Os valores encontrados em cada segmento para furosemida complexada foram: 8,58 ± 0,002 x 10-5 cm.s-1; 9,15 ± 0,003 x10-5 cm.s-1 e; 8,06 ± 0,002 x 10-5 cm.s-1, respectivamente para duodeno, jejuno e íleo enquanto que para furosemida pura encontraram-se os seguintes: 3,42 ± 0,08 x 10-5 cm.s-1 para duodeno; 3,87 ± 0,11 x 10-5 cm.s-1 para jejuno e 3,08 ± 0,001 x 10-5 cm.s-1 para íleo. Assim sendo, os valores obtidos para a permeabilidade da furosemida complexada foram significativamente superiores (p < 0,05) aos da furosemida pura, sugerindo que, a ciclodextrina pode ter influência no mecanismo de transporte da furosemida, que é via passiva paracelular. Quanto aos mecanismos envolvidos na permeabilidade da furosemida através dos enterócitos, pode-se sugerir que observou-se pouca influência dos inibidores da glicoproteína P (P-gp) e da enzima CYP3A4, sugerindo que não há uma participação importante destes mecanismos em sua absorção intestinal. / Furosemide, which is a diuretic drug, is widely used in heart, kidney and pulmonary disease treatments. The absorption is problematic with high variability inter and intra individuals. This drug has been classified as belonging to class II (low solubility and high permeability) or IV (low permeability and low solubility) of the Biopharmaceutical Classification System (BCS). In previous studies of the research team, Spricigo and colleagues (2008) and Silva (2014) developed complex of furosemide with hydroxypropyl-&#946;-cyclodextrin which allowed the optimization of the solubility of this drug. However, datas concerning it\'s intestinal permeability, when complexed, have not been determined. Addicted to this, the literature shows many information regarding to this parameter, which confirms the importance of the evaluation of the permeability of this drug. Some techniques have been employed in order to evaluate the intestinal permeability of drugs. In the present work, a triple single-pass intestinal perfusion technique was used for three different segments. This technique enables the evaluation of the permeability of different segments in the same animal and also has interesting features such as: it provides during all the experiment conditions closer to those found in in vivo process of a drug absorption in the gut; blood supply; intact innervations; preservation of membrane transporter proteins and presence of mucus layer. This study was divided into the following steps: (i) obtaining furosemide complexed with hydroxypropyl-&#946;-cyclodextrin, (ii) characterization of drugs using techniques of thermal analysis, (iii) perfusion study in situ triple passage in three segments (duodenum, jejunum and ileum) from male Wistar rats in the absence and presence of inhibitors of P-glycoprotein and metabolizing enzymes CYP3A4 and subsequential statistical analysis of the impact of the cyclodextrin and the inhibitors in the permeability of furosemide and (iv) histological analysis of intestinal microvilli after in situ perfusion assay in three segments. The values found in each segment for complexed furosemide were: 8,58 ± 0,002 x 10-5 cm.s-1; 9,15 ± 0,003 x 10-5 cm.s-1; 8,06 ± 0,002 x 10-5 cm.s-1, respectively for duodenum, jejunum and ileum while for pure furosemide, the values were: 3,42 ± 0,08 x 10-5 cm.s-1 to duodenum; 3,87 ± 0,11 x 10-5 cm.s-1 to jejunum and 3,08 ± 0,001 x 10-5 cm.s-1 to ileum. Thus, the values obtained for the permeability of the complexed furosemide were significantly higher (p < 0,05) than those found for pure furosemide, suggesting that the cyclodextrin might have an influence on the transport mechanism of furosemide, which is passive paracellular route. About the mechanisms involved in the permeability of furosemide through the enterocytes, it can be suggested that there was little effect of P-glycoprotein (P-gp) inhibitors and CYP3A4 enzyme, suggesting that there is an important role of these mechanisms in the furosemide intestinal absorption.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-25T20:49:09Z No. of bitstreams: 1 brunocortesdesouza.pdf: 4659510 bytes, checksum: 73ac58d8200d2432ce64c9ebbd6d8c94 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-26T13:11:08Z (GMT) No. of bitstreams: 1 brunocortesdesouza.pdf: 4659510 bytes, checksum: 73ac58d8200d2432ce64c9ebbd6d8c94 (MD5) / Made available in DSpace on 2017-05-26T13:11:08Z (GMT). No. of bitstreams: 1 brunocortesdesouza.pdf: 4659510 bytes, checksum: 73ac58d8200d2432ce64c9ebbd6d8c94 (MD5) Previous issue date: 2017-02-20 / Esse trabalho apresenta estudos, modelagem e análises de um sistema de bombeio centrífugo submerso (BCS), considerando as características dos principais componentes presentes neste sistema. As contribuições do trabalho estão na partida do BCS, como no desenvolvimento de soluções para mitigar alguns dos problemas observados, como por exemplo, os relacionados à qualidade de energia elétrica nos terminais do BCS. A modelagem de cada equipamento elétrico que compõe o BCS é apresentada no trabalho, destacando-se alguns dos aspectos operacionais relevantes que são considerados na operação. Foi feito um projeto para dimensionamento dos filtros passivos utilizados na atenuação das componentes harmônicas das tensões e correntes produzidas pelo sistema, além de auxiliar na regulação da tensão no ponto em que o BCS está conectado. Nas simulações realizadas, considerou-se um sistema de média tensão com um motor de indução trifásico em gaiola de esquilo de 3835HP que acoplado a uma bomba centrífuga possui um alto coeficiente de inércia. Com a inserção de modelos de atritos rotacionais para o torque do conjunto motor-bomba, pôde-se representar os efeitos que acontecem nos instantes iniciais da partida do sistema e avaliar o desempenho da estratégia de controle utilizada para o acionamento. Assim como ocorre nos sistemas reais que são alimentados por cabos submarinos de longo comprimento, utilizou-se um sistema de controle do sistema em malha aberta com uma metodologia para estimar e compensar a queda de tensão que ocorre entre os terminais do conversor e o terminal de entrada do motor elétrico. O trabalho apresenta ainda uma breve comparação entre o conversor fonte de tensão (VSC) de 2 níveis e o conversor de 3 níveis com neutro grampeado (NPC). Por fim, é analisada a situação onde a alimentação do BCS é desequilibrada devido à diferença de valores entre os parâmetros do cabo submarino. / This work shows studies, modelling and analyses of an electrical submersible pump system (ESP), considering the characteristics of key elements in this system. The contributions are in its start-up, as also in the development of solutions for mitigation of some observed problems, e.g., those related to power quality at the equipment terminals. The model for each electrical equipment inside the ESP is presented in this work and highlighted some of the pertinent operational aspects that is commonly considered on practical operation. A project is settled for sizing the passive filters to attenuate the harmonic components of the voltages and currents supplied by the grid, in addition to helping voltage regulation at ESP connection point. In the study cases, it was considered a medium voltage power system with a 3835HP three phase squirrel cage induction motor which is connected with a centrifugal pump that results in a high inertia coefficient. Rotational friction model is considered in the studies to characterize the effects that occur at the initial seconds of the start-up of the system and also to evaluate the performance of the implemented control strategy. In the same way that occurs in real systems that are supplied by downhole electric cables, it was considered an open-loop V/f control with a methodology to estimate and compensate the voltage drop that exists between the terminals of the converter and the motor input. This work also establishes a short comparison between a 2-level voltage source converter (VSC) and a 3-level neutral-point clamped (NPC) VSC. Finally, the system is analyzed through the occurrence of an unbalance of downhole electric cable parameters.

Institute for Rural Development / MRDV