A pesquisa aqui proposta tem como objetivo a análise de \"Campo Geral\", presente no primeiro volume do ciclo de novelas Corpo de Baile, de Guimarães Rosa, publicado em 1956. O recorte da investigação incidirá sobre a questão das perdas afetivas vividas por suas personagens, observando a maneira pela qual as superações e ganhos se configuram (ou não) ao longo das obras. Essas perdas se misturam às contextuais, pois o espaço do sertão onde habitam é marcado pela precariedade em diversos níveis. Na tentativa de apreender o caminho percorrido pelas personagens durante o processo de reelaboração de cada perda, alguns elementos da teoria psicanalítica serão de grande valia, sobretudo os expostos em A Interpretação dos Sonhos (FREUD, 1900) e nos ensaios \"Luto e Melancolia\" (FREUD, 1917) e Escritores criativos e devaneios (FREUD, 1908), para ampliar o olhar analítico-interpretativo a ser lançado sobre os textos. A isso serão incorporados os principais traços do contexto sertanejo, responsáveis direta ou indiretamente por tais perdas, aspecto que demandará o auxílio de certos estudiosos do autor mineiro, voltados especificamente para a pesquisa histórico-social de sua produção, entre eles Bolle (2004) e Roncari (2004). / This research aims to analyze Campo Geral, which is presented in the first volume of the cycle of Corpo de Baile by Guimaraes Rosa, published in 1956. The selection of the investigation will focus on the issue of the emotional losses experienced by the characters, observing the way in which the triumphs and gains are designed (or not) along the work. These losses are mingled with their contexts, once the environment (sertão) they inhabit is affected by the precariousness in several ways. Aiming to apprehend the experience lived by the characters during the whole processes of re-elaboration of each loss, some elements of the psychoanalytical theory will have a great value, especially the ones presented in A Interpretação dos Sonhos (FREUD, 1900) and in the essays \"Luto e Melancolia\" (FREUD, 1917) and Escritores criativos e devaneios (FREUD, 1908) in order to extend the analytical interpretative view through which the texts will be scrutinized. The main traces of the sertanejo context will be incorporated to this, since they are directly or indirectly responsible for such losses; this will require the support of certain researchers of the author who specifically contemplate the socio-historical research of its work, such as Bolle (2004) and Roncari (2004).

A partir da hipótese de que carbonetos de ferro podem agir como fonte motora para nucleação de novos domínios magnéticos, o que tenderia a reduzir a taxa de crescimento da dissipação de energia anômala em função da frequência de excitação, três aços de grão não orientado com diferentes teores de carbono foram estudados. A amostra do aço totalmente processado continha 79 ppm de carbono e 2% silício, já o aço semiprocessado continha 340 ppm de carbono e a partir deste um terceiro conjunto foi produzido por descarbonetação contendo 110 ppm de carbono. As amostras foram envelhecidas consecutivamente em atmosfera inerte sob temperatura de 150 e 225 °C e tiveram suas propriedades magnéticas e microestruturais avaliadas em diferentes intervalos de tempos. Métodos, estes, que foram empregados com intuito de se estudar o efeito da precipitação de carbonetos na dissipação de energia anômala. O envelhecimento mecânico do aço com 340 ppm de carbono foi evidenciado após 6 horas de envelhecimento em um único pico, já o aço com 79 ppm de carbono e 2% silício apresentou um pico de envelhecimento mecânico a 75 horas. Por sua vez o aço contento 110 ppm de carbono apresentou um pico de dureza tardio, após 30 horas de envelhecimento sob 225 ºC Ficou evidenciado que o incremento do campo coercivo está ligado ao aumento do diâmetro da partícula. Essa tendência é verdadeira para carbonetos com faixa de tamanho de 0,5-0,65 ?m para a liga com 79 ppm carbono e 2% silício e de 0,55-0,81 ?m relativo à liga contendo 340 ppm de carbono. De maneira oposta, não foi identificado relação clara entre o tamanho dos carbonetos e a majoração de HC nas amostras da liga contento 110 ppm de carbono. O envelhecimento magnético mostrou-se mais deletério às propriedades magnéticas dos aços semiprocessados e totalmente processados quando estas são mensuradas em baixas frequências (f<60Hz). De maneira geral, foi observado que o envelhecimento porcentual (IE%) decresce com o aumento da frequência de excitação para o mesmo tempo e temperatura de envelhecimento. A respeito do emprego das amostras envelhecidas em altas frequências de excitação, a liga do aço totalmente processado apresentou menor dissipação de energia somente em frequência de excitação superiores a 1,5 kHz. Por sua vez, a liga semiprocessada contendo 340 ppm de carbono envelhecida por 6 e 12 horas mostrou-se menos dissipativa quando empregada sob indução de 1T, em frequências superiores a 640 e 900 Hz, respectivamente. O aço contendo 110 ppm de carbono apresentou os melhores resulto das ligas estudadas, como frequência de cruzamento abaixo dos 3 kHz e 700 Hz sob 1 e 1,5T, respectivamente. Elementos teóricos e empíricos dão conta de que o refinamento dos domínios magnéticos tende a ocorrer mais facilmente sob altas indução do que em baixas induções. O que implica em melhores resultados sob indução de 1,5T. O aumento da densidade dos domínios magnéticos foi constatado pelas imagens realizadas com luz polarizadas nas amostras do aço totalmente processado (70 ppm C e 2%Si). Os domínios magnéticos da amostra contendo 110 ppm de carbono, observados pela mesma técnica, apresentaram morfologia mais refinada o que dificultou a sua quantificação. Devido à precipitação dos carbonetos épsilon e cementita em planos de hábito na matriz ferrítica, é possível conjecturar que apenas 1/3 destes terão alta capacidade de ancoramento das paredes de domínios, uma vez que, apenas esta fração de precipitados terão seu menor eixo paralelo à direção de magnetização. / Three non-oriented electrical steels with different carbon content has been studied based on the hypothesis that iron carbides can act as a source of nucleation of new magnetic domains, which would then lead to a reduction in the growth rate of the anomalous energy dissipation as a function of the excitation frequency. Samples of the fully processed steel contained 79 ppm of carbon and 2% silicon, while the semi-processed steel contained 340 ppm of carbon, and from this alloy a third alloy containing 110 ppm of carbon was produced by decarburization. The samples were consecutively aged under inert atmosphere and at temperatures of 150 and 225°C, as well as had their magnetic and microstructural properties evaluated at different time intervals. The mechanical aging of the steel containing 340 ppm of carbon was evidenced after 6 hours of aging in a single peak, the steel containing 79 ppm of carbon and 2% silicon presented even a mechanical aging peak at 75 hours. In turn, samples of the NOES containing 110 ppm of carbon showed a late hardness peak after 30 hours of aging at 225°C. It was found that the increase in the coercive field is linked to the increase in the particle diameter. This trend is true for carbides with a size range of 0.5-0.65 ?m for the alloy containing 79 ppm carbon and 2% silicon, and 0.55-0.81 ?m for the alloy containing 340 ppm carbon. In contrast, no clear relationship was found between the carbide size and the coercive field increase in the samples of the NOES containing 110 ppm of carbon. Magnetic aging has been shown to be less deleterious to the magnetic properties of semi-processed and fully processed steels when they are measured at high frequencies (f >60Hz). Regarding the use of samples aged at high excitation frequencies, the alloy of the fully processed steel showed a lower energy dissipation only at excitation frequencies above 1.5 kHz. On the other hand, the steel containing with 340 ppm of carbon aged for 6 and 12 hours were less dissipative when employed under 1T induction at frequencies above 640 and 900 Hz, respectively. The NOES containing 110 ppm of carbon presented the best results of all the alloys studied, being able to be applied below 3 kHz and 700 Hz under 1 and 1.5T, respectively. Theoretical and empirical elements indicate that the magnetic domains refinement tends to occur more easily under high induction than under low inductions. This implies better results under and induction of 1.5T. The increase in the density of the magnetic domains was verified by light polarized images of the samples of the fully processed steel (70 ppm carbon and 2% silicon). The magnetic domains of the NOES110 sample observed using the same technique presented more a refined morphology, which made it difficult to quantify them. Due to the precipitation of the carbides epsilon and cementite in habit planes in the ferritic matrix, it is possible to conjecture that only a third of these will have a high anchoring capacity of the domain walls, since only this fraction of precipitate will have its smaller axis parallel to direction of magnetization.

Made available in DSpace on 2016-03-15T19:37:53Z (GMT). No. of bitstreams: 1 Lucca Zamboni.pdf: 861341 bytes, checksum: 140f5571ef3e3bfdab49cd1cb7cecfff (MD5) Previous issue date: 2007-03-19 / Ant colonies can be considered a multi-agent system, where each agent (ant) works independently by simple rules. Algorithms based on the behavior of ant colonies have been used to solve optimization problems, because in the search for food ants tend to create the shortest (optimum) path between the nest and the food source. In this work, ant inspired algorithms are used in the optimization of the topology of electric energy distribution networks. The algorithm performance is investigated in function of its parameter values. Experiments in hypothetical and actual distribution systems are performed. / Colônias de formigas podem ser consideradas um sistema multi-agente, em que cada agente (formiga) opera independentemente por regras simples. Algoritmos baseados no comportamento de colônias de formigas têm sido usados para resolver problemas de otimização, pois, na procura por alimento, as formigas tendem a estabelecer a rota mais curta (ótima) entre o formigueiro e a fonte de alimento. Neste trabalho, usam-se algoritmos inspirados em formigas na otimização da topologia de circuitos de distribuição de energia elétrica. O desempenho do algoritmo é investigado em função dos valores dos seus parâmetros. Realizam-se experimentos em sistemas de distribuição hipotéticos e realistas.

O Brasil é o maior produtor de lima ácida \'Tahiti\' (Citrus latifolia Tanaka), uma fruta de origem tropical pertencente à família Rutaceae. O beneficiamento pós-colheita desta fruta visa conservar a qualidade obtida no campo por mais tempo, entretanto, injúrias mecânicas podem ocorrer neste processo, elevando a perda de qualidade e, reduzindo a vida útil e o valor comercial dos frutos. Este trabalho foi dividido em duas etapas, as quais deram origem a dois artigos que objetivaram: (1) Avaliar a influência da colheita e do beneficiamento pós-colheita na qualidade e conservação de lima ácida \'Tahiti\', (2) Identificar os pontos críticos de impacto na linha de beneficiamento de lima ácida \'Tahiti\', e avaliar a influência desses pontos na qualidade e na conservação pós-colheita. Na etapa 1, os frutos foram coletados na planta e na linha de beneficiamento, sendo os tratamentos denominados: colheita, secagem, fungicida e giberelina, cera e embalagem. Na etapa 2, os frutos foram coletados diretamente das plantas e submetidos a impactos visando simular aqueles da linha de beneficiamento. Foram realizadas análises físico-químicas de rendimento do suco, acidez titulável, sólidos solúveis, ácido ascórbico, clorofila total, perda de massa, coloração da casca (colorímetro e escala de cor), incidência e severidade de oleocelose, e avaliação visual (podridões, murchamento, danos físicos, coloração e perda do cálice). Também foram realizados experimentos sensoriais considerando frutos coletados na linha e com os impactos simulados em laboratório, cada qual em duas condições de armazenamento (refrigerado e ambiente). O beneficiamento contribui para a manutenção de características físico-químicas importantes para a lima ácida \'Tahiti\', todavia, os resultados obtidos nestes trabalhos apontam que as condições da linha e os impactos a que os frutos são submetidos durante o beneficiamento influem negativamente na qualidade. Na etapa 1, constatou-se com o beneficiamento redução no conteúdo de sólidos solúveis no último dia de armazenamento, queda dos cálices e, maior incidência e severidade de oleocelose. Além disto, o beneficiamento completo acarretou numa maior porcentagem de murchamento e perda da coloração verde da casca dos frutos, sobrepujando os efeitos positivos da giberelina e da cera. Na etapa 2, ao realizar a caracterização da linha, constatou-se magnitude total de 1788,6 G, variando de 23,9 G à 147,4 G dependendo do ponto de transferência. Nos frutos com impactos simulados houve perda da cor verde da casca, de sólidos solúveis, e de acidez titulável e, maior teor de ácido ascórbico, perda de massa, murchamento, queda do cálice e, incidência e severidade de oleocelose. Além disto, a análise sensorial apontou que a preferência dos provadores está alinhada aos níveis de impactos, com os frutos injuriados obtendo menor aceitabilidade para a aparência e, maiores intensidades de amargor e gosto de sobremaduro do suco. Os principais motivos que influenciam na tomada de decisão para o atributo aparência do fruto são incidência de distúrbios, turgidez e coloração da casca. A redução dos impactos na linha de beneficiamento pelo controle das alturas de quedas e do uso de tecnologias, como materiais amortecedores, contribui para a conservação de atributos importantes para a comercialização de lima ácida \'Tahiti\', reduzindo suas perdas pós-colheita e, gerando maiores lucros aos envolvidos na cadeia de produção. / Brazil is the largest producer of \'Tahiti\' acid lime (Citrus latifolia Tanaka), a fruit of tropical origin belonging to the Rutaceae family. The postharvest handling of this fruit aims to preserve the quality obtained in the field, however, mechanical injuries increases quality loss, reducing the fruit useful life and commercial value. This work was divided into two stages, which gave rise to two articles that objectified:: (1) To evaluate the influence of harvest and postharvest handling on the quality and conservation of \'Tahiti\' acid lime; (2) Identify the critical impact points of the \'Tahiti\' acid lime handling line, and to evaluate the influence of these points on quality and postharvest conservation. In step 1, the fruits were collected in the plant and in the handling line, being the treatments denominated: harvest, drying, fungicide and gibberellin, wax and packaging. In step 2, fruit were collected from the plants, being the same submitted to impacts aiming to simulate those of the handling line. Physicochemical analysis of the juice yield, titratable acidity, soluble solids, ascorbic acid, chlorophyll, weight loss, peel color (colorimeter and color scale), the incidence and severity oleocellose and visual evaluation (rotting, wilting, physical damage, coloring and loss of the calyx) were performed. Sensory experiments were also performed considering fruits collected in the line and with simulated impacts in the laboratory, each one under two storage conditions (refrigerated and ambient). The handling contributes to the maintenance of important physical and chemical characteristics for the \'Tahiti\' acid lime, however, the results obtained in these studies indicate that the conditions of the line and the impacts to which the fruits are submitted during the handling affect negatively the quality. In step 1, it was verified with the handling the reduction was observed in the content of soluble solids on the last day of storage, drop in the calyces and, greater incidence and severity of oleocellose. In addition, the complete handling resulted in a higher percentage of wilting and loss of the green color of the fruit peel, overcoming the positive effects of gibberellin and wax. In step 2, when performing the line characterization, a magnitude of 1788.6 G was found, varying from 23.9 G to 147.4 G depending on the transfer point. In fruits with simulated impacts there was loss of the green color of the peel, soluble solids, and titratable acidity and higher ascorbic acid content, weight loss, wilting, and drop the calyx, oleocelose incidence and severity. In addition, the sensorial analysis showed that the preference of the tasters agrees with the impact magnitude levels, with the injured fruits obtaining less acceptability for the appearance, higher intensities of bitterness and taste overriper of juice. The main reasons that influence in the decision making for the attribute appearance are incidence of disorders, turgidity and coloration of peel. Reducing impacts on the handling line for control of falls and the use of technologies such as bumpers materials, contributes to the conservation of important attributes for the marketing of \'Tahiti\' acid lime, reducing its postharvest losses and generating higher profits to those involved in the production chain.

Perdas de água em redes de distribuição acontecem por diversas razões, uma delas, o excesso de pressão, pode ser prevenido através da divisão das redes em Distritos de Medição e Controle. Este método vem sendo utilizado há algum tempo como modo de prevenir sobrepressão na rede, aumentando a confiabilidade e vida útil das tubulações e dispositivos do sistema. Atualmente, alguns autores propõem diferentes tipos de metodologias para uma eficiente definição de Distritos de Medição e Controle. Neste trabalho foi criada e aplicada uma metodologia baseada no estudo de uma área (Setor Aracy) na cidade de São Carlos - SP guiado por análise topográfica. A rede de distribuição do setor de abastecimento foi analisada indicando um subdimensionamento em alguns trechos, assim como, foi concluído que já existe uma setorização na área que não foi guiada por análise topográfica e sim por implantação dos loteamentos. Um estudo de setorização que tem como objetivo o gerenciamento de pressões deve ser norteado por análise da topografia do local juntamente com dispositivos gerenciadores de pressão (válvulas, boosters etc). / Water losses in network distribution systems may happen due to many reasons, one of them, the overpressure, can be prevented through the partitioning of these networks in District Metered Areas. This method has been used for some time as a way of preventing network overpressure, enhancing the reliability and lifespan of pipes and system devices. Currently, some authors propose different methodologies to an efficient delimitation of the District Metered Areas. In this work, a methodology was conceived and applied based on the study of an area (Aracy Sector) in the city of São Carlos - SP guided by topographic analysis. The distribution network of the supply sector was analyzed indicating an undersize in some pipes, as well as, it was concluded that a sectorization already exists in the area that is not guided by topographic analysis, but by the implementation of the allotments. A sectorization study that aims to manage pressures should be guided by topographic analysis of the site, together with pressure management devices (valves, boosters etc).

Eutrophication is an increasing problem in the Baltic Sea and is caused by an excess of nutrients in the water which are primarily transported with the runoff from cultivated land. The peninsula Vikbolandet in Östergötland is dominated by arable land and has stream outflows to the bays of Bråviken and Slätbaken. In this study five streams of Vikbolandet have been sampled during the spring flood period with the aim of connecting concentrations of nutrients in the streams with turbidity and runoff in the catchment. This analysis has then been related to the land use in the small catchment of Vadsbäcken in order to investigate the impact of land uses with areal losses of phosphorus. The results indicate that there are increasing concentrations of phosphorus downstream in the sites of Vadsbäcken and that the transported amounts of phosphorus increases with the spring flood and at a rainstorm event. It is shown that the distribution of agricultural blocks in the catchment of Vadsbäcken has a major impact on the nutrient leakage. There is a co-variation between turbidity and runoff during a rainstorm event and between particulate-bound phosphorus and runoff over time. A further aim has been to investigate possibilities for use of an easily managed, cost-effective environmental monitoring method for nutrient measurements in watercourses. Within four out of five streams at Vikbolandet there is a significant co-variation between turbidity and total phosphorus. Using field measurements of turbidity for environmental monitoring could provide a viable alternative for environmental monitoring of watercourses but will need further investigations of co-variation before being brought into use. Further, this study shows that the transport of phosphorus is underestimated in environmental monitoring

Les composants magnétiques sont des constituants essentiels des convertisseurs électroniques de puissance en termes de volume et de coût, en particulier dans les alimentations à découpage. Pour cette raison, il est intéressant de développer des méthodes et des outils logiciels pour optimiser la conception de dispositif magnétiques en relation avec les paramètres de conversion. Concevoir et optimiser un composant magnétique suppose de définir parfaitement les contraintes induites par les spécifications, de choisir des conducteurs, isolants et circuits magnétiques, tant sur le plan des matériaux que des géométries, de calculer finement les pertes dans ces différentes parties et enfin, de disposer de modèles thermiques permettant de conduire le design en considérant la contrainte majeure que constituent les températures de fonctionnement des différentes parties du composant. L'objectif de cette thèse est de jeter les bases d'un outil générique d'aide à la conception optimale de composants magnétiques en s'appuyant sur des modélisations analytiques et numériques. / The magnetic components are essential constituents of the power electronic converters in terms of volume and cost, particularly in switching power supplies. Therefore, it is essential to develop methods and software tools that can optimize the magnetic device design in relation to the conversion parameters. The design and optimization of the magnetic component includes several constraints that are imposed by the specifications including the choice of electrical conductors and magnetic circuits, both in terms of materials and their geometries. It is necessary to calculate the losses in these parts and to know the thermal models that allows a better design by considering the major constraint namely, the operation temperatures of different parts of the component.The current work describes the basics of a generic tool that will help in the optimal design of a magnetic components based on both analytical and numerical modeling.

In recent years, the interest for parallel multicell converters has grown, which is partially due to the possibility of coupling the inductors used to connect the different commutation cells together. Coupling the inductors to form an InterCell Transformer (ICT) does not usually modify the output current, but it reduces the current ripple in the windings and the flux swing in some regions of the core. It can be shown that this brings a reduction of copper and core losses in the magnetic component. The reduction of the phase current ripple also reduces the difference between turn on and turn off current in the switches, which brings a reduction of switching losses for devices generating more losses at turn off than at turn on. The design of an ICT is not that different from any other magnetic component but it is very specific and inherent features must be taken into account. Taking full benefit of the potential advantages of ICTs requires the development of special tools and methods which are the focus of the study. We show how to design ICTs considering several topologies and different methods, from the most precise and time-consuming to the less accurate but more quickly calculated. The explanation of the ICT design is divided in four main parts: Copper Losses, Core Losses, Flux Density Saturation and Thermal Aspects. Further attention is given to high frequency copper losses since complex phenomena such as skin and proximity effects highly influence the ICT design. Based on Finite Element Method simulations, smart practices are suggested to reduce high and low frequency copper losses, not only in ICTs but also in inductors and transformers. Simple tables are developed to help transformer designers to identify the best configuration of conductors inside a given core window, depending on the current waveform and frequency, number of turns and geometrical parameters. Optimization routines to reduce the ICT total mass, volume, losses or cost are developed and multidimensional interpolation of pre-simulated values of AC resistance and leakage inductance is used to speed up the optimization routine. Comparison of ICT designs with regard to core and conductor material, number of cells and switching frequency is performed. Comparison with regular inductors is also made in order to verify the benefits of this kind of magnetic component. Multilevel converter control aspects applied to three- hase systems is also investigated in terms of the ICT flux. Zero sequence signals, specific for a PWM strategy and converter/load topology, are created in order to minimize the flux in ICTs and consequently reduce even further the mass and size of these components. Comparison between several PWM methods are performed and experimentally verified.

Over the last few decades, wind power has shown a continuous and significant developmentin the energy market globally. Having reached a certain level in both technologyand in dimensions, the role of optimizing wind turbines as well as wind farms hasbecome an additional aspect to future development and research. Since turbine wakescan cause significant power deficits within a farm, research in this area has the potentialfor large improvements in wind farm design. A wake is described as the downstream flow behind the rotor of an operating windturbine. The two main characteristics of wakes are a velocity (momentum) deficit and anincreased turbulence level. The velocity deficit behind the upwind turbine results in apower loss of the downstream turbines, whereas the higher turbulence causes additionalloads on the downstream turbines’ structures resulting in fatigue problems. The study of wakes is a complex topic, they are influenced by an interconnection of anumber of parameters like ambient wind speed and turbulence, atmospheric stabilityconditions (stable, unstable, and neutral), the turbines’ operational characteristics, andthe terrain properties. In order to assess the power deficits affected by wake interaction between turbines,an analysis can be realized by processing SCADA data of turbines in a wind farm. The collected data is treated by a comprehensive filtration process, excluding events of icing, curtailment, faults, etc. and by grouping into different atmospheric conditions, windspeed intervals and wind speed sectors. Finally, power deficit values, as a function ofwind direction, are calculated and quantified, and thereafter analyzed to assess the wakebehavior at different conditions for different cases.In this thesis, the wake-induced power deficit has been investigated in a specificstudy case for three pairs of two neighboring turbines in a forested moderately complexterrain using SCADA data. The production losses amounted between the range of 32% to 67% for the specific site with turbine spacing around 4D. The obtained results werepartially unsatisfactory, caused by the reasons of inaccurate wind direction values due toyaw misalignment issues and challenging separation into different stability conditions. Moreover, the power deficits showed a clear reduction of losses with increasing windspeed. A conclusion regarding the differences between stable and near neutral conditionscould not be determined from the data.

Le travail de cette thèse porte sur l'étude des pertes AC dans les supraconducteurs pour des applications tels que les câbles ou les aimants. Les modélisations numériques rapportées sont de type éléments-finis et méthode intégrale. Toutes ces méthodes visent à résoudre à calculer les distributions de densité de courant et de champ magnétique en prenant en compte différents loi de comportement pour le supraconducteur. Deux conducteurs sont introduits dans ce mémoire. Tout d'abord, les supraconducteurs à haute température critiques sont étudiées avec l'introduction d'une nouvelle forme de conducteur (fils cylindriques) et sont envisagés pour des câbles fort courant de 3~kA. Dans un second temps, des simulations numériques 3-D sont réalisés sur un conducteur MgB2. Le chapitre suivant traite des contraintes de calculs des pertes dans le but de dimensionner l'ensemble des pertes d'un câble complet. Enfin, les modèles numériques développés précédemment sont utilisé sur un exemple concret : le démonstrateur 10~kA fait à l'aide du conducteur MgB2 dans le projet BEST-PATHS / The work reported in this PhD deals with AC losses in superconducting material for large scale applications such as cables or magnets. Numerical models involving FEM and integral methods have been developed to solve the time transient electromagnetic distributions of field and current density with the peculiarity of the superconducting constitutive E-J equation. Two main conductors have been investigated for two ranges of superconducting cables. First, REBCO superconductors working at 77 K are studied and a new architecture of conductor (round wires) for 3~kA cables. Secondly, for very high current cables, 3-D simulations on MgB2 wires are approach and solved using FEM modeling. The following chapter introduced new development used for the calculation of AC losses in DC cables. The thesis ends with the use of the developed numerical model on a practical example in the BEST-PATHS project: a 10 kA MgB2 demonstrator.