998 resultados para Caminhos de fluxo curtos


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A máquina elétrica de relutância comutada (MERC) é, inerentemente, um conversor eletromecânico de velocidade variável, facilmente controlado através dos instantes de excitação e desexcitação do circuito magnético partilhado pelas fases. A sua robustez e simplicidade construtiva (só enrolamentos concentrados no estator), flexibilidade de controlo, bom rendimento numa gama alargada de velocidades, a sua fiabilidade e tolerância a defeitos fazem desta máquina uma opção válida para sistemas de conversão de energia caraterizados por baixas velocidades. A tendência crescente de instalar turbinas eólicas em offshore, para além dos desafios económicos e tecnológicos que levanta, torna a fiabilidade e a tolerância a defeitos, requisitos de vital importância. Neste contexto, a potencial aplicação da MERC a geradores eólicos sem recurso a caixa de velocidades, já que esta penaliza o custo, o volume e a fiabilidade do sistema, serviu de motivação a este trabalho. Nesta dissertação apresentam-se, numa perspetiva comparativa, diferentes paradigmas construtivos da MERC para o funcionamento gerador em regime de baixas velocidades, caraterístico dos aproveitamentos de energias renováveis. Para o efeito, formularam-se leis de escala apropriadas a análises dimensionais de topologias diferenciadas pelas caraterísticas dos circuitos elétrico e magnético e do seu posicionamento relativo. Estes modelos de escala permitiram introduzir constrangimentos físicos e dos materiais que condicionam o projeto da máquina, como a saturação magnética e limites de temperatura. Das análises dimensionais e validação com elementos finitos, elegeu-se uma estrutura magnética modular com caminhos de fluxo curtos que foi comparada com um protótipo de MERC regular, previsto para equipar um gerador eólico. Quando comparadas as duas topologias, assumindo dimensões idênticas, a modular apresentou um significativo ganho de potência específica mantendo bons níveis de rendimento. Pretende-se assim alargar a discussão do projeto das MERC, geralmente confinado a topologias regulares, a um contexto mais abrangente que inclua novos paradigmas construtivos.

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O desenvolvimento da erosão hídrica ocorre em resposta ao modo como a água se move através e sobre uma determinada paisagem. O modelo digital de elevação (MDE) deve, portanto, ser o mais preciso possível, uma vez que constitui a base para a análise do relevo. Este trabalho teve como objetivo definir um modelo digital de elevação hidrologicamente consistente (MDEHC) e o método de direção de fluxo mais adequado para a definição da rede de drenagem na sub-bacia do horto florestal Terra Dura, município de Eldorado do Sul, RS. Foram testados os modelos gerados com os interpoladores Topogrid e redes triangulares irregulares (Triangulated Irregular Network -TIN) linear (TIN L) e TIN natural neighbor (TIN NN). A qualidade em relação às análises hidrológicas foi avaliada por meio da comparação das curvas de nível geradas pelos modelos testados com as curvas originais da sub-bacia (escala 1:10.000); da avaliação da quantidade de áreas planas; e da comparação da drenagem gerada pelos modelos a partir dos métodos de direção de fluxo Deterministic (D8) e Deterministic infinity (D∞ ou D infinito) com a drenagem original. Entre os modelos avaliados, o Topogrid apresentou maior consistência hidrológica, verificada na melhor continuidade das curvas de nível (menos arestas) e maior detalhamento da área de drenagem e divisores, acarretando menor quantidade de áreas planas e caminhos de fluxo mais detalhados, independentemente do método de direção de fluxo utilizado. Em relação à rede de drenagem, o método distribuído D∞ obteve melhor desempenho na descrição dos caminhos de fluxo, comparado ao método de direção única D8. O MDEHC Topogrid associado ao método D∞ proporcionou a identificação mais precisa dos caminhos preferenciais do fluxo que formam a rede de drenagem.

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This work has as main objective to show all the particularities regarding the Three-phase Power Summation Method, used for load flow calculation, in what it says respect to the influence of the magnetic coupling among the phases, as well as to the losses presented in all the existent transformers in the feeder to be analyzed. Besides, its application is detailed in the study of the short-circuits, that happen in the presence of high impedance values, which possess a problem, that is its difficult detection and consequent elimination on the part of common devices of protection. That happens due to the characteristic presented by the current of short¬ circuit, in being generally of the same order of greatness that the load currents. Results of simulations accomplished in several situations will be shown, objectifying a complete analysis of the behavior of the proposed method in several types of short-circuits. Confront of the results obtained by the method with results of another works will be presented to verify its effectiveness

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Visando à obtenção de informações técnicas que auxiliem aprimorar a eficiência hidráulica de filtros de areia nos processos de filtragem e retrolavagem, buscou-se avaliar o potencial de utilização de uma bancada didática de túnel de vento como método de visualização e caracterização das linhas de fluxo geradas pela interação da geometria de um modelo de dreno (crepina) com diferentes velocidades de escoamento. Os ensaios foram realizados, instalando-se um modelo comercial de dreno, do tipo cilíndrico, em um módulo experimental construído para ser acoplado a um túnel de vento vertical. Simularam-se as três vazões de escoamento de ar fornecidas pelo módulo, obtendo-se registros fotográficos com uma câmara de alta velocidade, cujas imagens foram tratadas para destacar a disposição das linhas de fluxo e os caminhos preferenciais de escoamento para os sentidos de escoamento de filtragem e retrolavagem. Correlacionou-se, por similitude, o intervalo de operação do túnel de vento com valores de vazão praticados em processos de filtração com água, em filtros de areia comerciais, com 40; 60 e 100 cm de diâmetro. Os resultados obtidos validaram a metodologia proposta, permitindo analisar o efeito da geometria da crepina nas linhas de fluxo experimentais, tanto no modo de filtragem quanto no de retrolavagem.

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Este trabalho tem como objetivo comparar diferentes métodos de previsão de necessidades de caixa no overnight, que assegurem que a liquidez de um produto financeiro específico – neste caso, o Call Deposits (Depósito à Vista, em moeda estrangeira) – seja suficiente para cobrir os riscos de liquidez de uma instituição financeira e, em contrapartida, otimizem o lucro oriundo do saldo restante que ultrapasse o valor de saída destes modelos. Para isso, o modelo de Fluxo de Caixa de Schmaltz (2009), que segrega os diferentes componentes do caixa (determinísticos e estocásticos), será utilizado para determinar as necessidades de caixa e, através do método de Monte Carlo para a previsão de diferentes caminhos, chegamos a um valor médio de saldo para ser utilizado no overnight. Como comparativo, será utilizado o modelo determinístico de Ringbom et al (2004), que oferece a “Taxa de Reserva de Maximização de Lucro”, para, enfim, compará-los historicamente, entre Jan/2009 e Dez/2013, a fim de concluirmos qual dos modelos de reservas de caixa se mostra mais satisfatório. A base de dados utilizada replica os saldos e saques de um banco comercial, para o produto financeiro em questão, e, também, é utilizada para a estimação dos parâmetros.

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The railroad, from 1870 and on, becomes an usual complaining in the press s and politician elite s speeches, especially because of Natal s geographic isolation. The implantation of two railroads in the capital territory Estrada de Ferro de Natal a Nova Cruz, afterwards part of Great Western Railway Company network, and Estrada de Ferro Central do Rio Grande do Norte had serious implications in the urban environment. While railroad s structures were already consolidated, other transportation mechanisms were being implanted in the first decades of the 20th century, such as trams lines, which, by the way, was a transport modal that also used rails as a dislocation meaning. Considering these questions, we may ask: how come railroads and tramways demands, roads and buildings had influenced the internal organization of Natal? We work with the general hypothesis that the influence of technical networks, composed by tramways and railroads, over Natal s urban space happened in a diversified way, sometimes consolidating social aspects in certain areas, sometimes improving the occupation of others. The impact over the city s territory also happens in a diversified way between the buildings/railroad s complexes and the pathways. The different scale of the train in comparison to the trams velocity, size, noise level, flow, among others is also a cause to the different consequences in urban environment. The main objective of this work is to understand the role of circulation technical networks in the construction process of urban space in Natal, as a way to contribute to the urban historiography about the subject. The time frame adopted, between 1881 and 1937, marks the time path of railroads and tramways in Rio Grande do Norte: 1881 is the year of railroad s first section inauguration from Natal to São José do Mipibu as well of the railroad complex in the Republic Square in Natal; the year of 1937 marks the beginning of tramways declination process in the city. At this time railroads and tramways had to face more intensively the competition of motor vehicles. The theory reference adopted is based on concepts and analysis of authors, such as Flávio Villaça and Roberto Lobato Corrêa references to the concepts of urban structure , localization and accessibility and Gabriel Dupuy to explain the concept of urban technical networks . These references reveal the conflict of different realities in the urban universe interests and values which is an important factor about the construction of urban space. The information sources used were from two distinctive natures: primary, journals of the time studied and official government reports, and secondary, based on other works about the subject. It was also used by this study iconographic source, especially images from the data base of the research group História da Cidade, do Território e do Urbanismo .

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The objective of the present work is develop a model to simulate electrical energy networks in transient and stead states, using the software ATP (Alternative Transient Program), able to be a way to join two distinct themes, present in classical methodology planning networks: short circuit analysis and load flow theory. Beyond that, using a tool for relay simulation, this paper intend to use the new developed model to investigate the influence of transient phenomenon in operation of protection relays, and calibrate the enterprise's protections relays. For testing the model, some relays, actually, installed at COSERN were used

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This paper aims to examine the genesis of migration to the city of Leme-SP, as well as the influence of the social matrix northeastern expansion and redevelopment through the territorialization of the migrant population, particularly workers from the state of Ceará, migration from the 1970s. This process is evidenced by the territorial division of labor, through the economic, political and cultural insecurity through the work of cutting sugar cane, the territoriality of culture and northeastern faith in the city, and becomes another object before the materiality in which occurs. In this aspect, through dialogue between the sciences and arts, it was possible to show the historical importance of the phenomenon of migration in the country, in different scales and relationship that encompasses everything and everyone

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Pós-graduação em Enfermagem (mestrado profissional) - FMB

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Esta dissertação tem por objetivo investigar a existência demotivações de gênero para o trânsito religioso de pentecostais para a Igreja Metodista. Para tanto, o primeiro passo é demonstrar a incidência deste fluxo migratório. Em seguida levantar e analisar as motivações paraa migração deste grupo para uma igreja protestante história. Neste sentido, o primeiro capítulo aborda assuntos correlatos ao tema como a religião, a modernidade e o campo religioso brasileiro, porque é no mundo que os papéis de gênero são remodelados e emerge a transitoriedade humana em um contexto de pluralidade e sincretismo religioso ao qual pertecem o protestantismo histórico e o pentecostalismo. O segundo capítulo descreve as origens domovimento metodista, sua entrada no Brasil e na cidade de São Paulo,as bases doutrinárias e costumes, bem como delimita o campo de pesquisa nela inserido, encerra com caracterização do trânsito religioso,destaca dados estatísticos, dinâmicas, razões e consequências sobre este fenômeno,cruzando-os com dados da pesquisa de campo realizada na Igreja Metodista do Distrito Grande ABC. Por fim, o terceiro capítulo, traz a tona à discussão sobre a questão de gênero, apresenta conceitos, caracterização e sua relevância na religião e no trânsito religioso, encerra com a análise das motivações deste fluxo migratório de pentecostais para a Igreja Metodista sob a perspectiva de gênero.

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This work aims to understand how cloud computing contextualizes the IT government and decision agenda, in the light of the multiple streams model, considering the current status of public IT policies, the dynamics of the agenda setting for the area, the interface between the various institutions, and existing initiatives on the use of cloud computing in government. Therefore, a qualitative study was conducted through interviews with a group of policy makers and the other group consists of IT managers. As analysis technique, this work made use of content analysis and analysis of documents, with some results by word cloud. As regards the main results to overregulation to the area, usually scattered in various agencies of the federal government, which hinders the performance of the managers. Identified a lack of knowledge of standards, government programs, regulations and guidelines. Among these he highlighted a lack of understanding of the TI Maior Program, the lack of effectiveness of the National Broadband Plan in view of the respondents, as well as the influence of Internet Landmark as an element that can jam the advances in the use of computing cloud in the Brazilian government. Also noteworthy is the bureaucratization of the acquisition of goods to IT services, limited, in many cases, technological advances. Regarding the influence of the actors, it was not possible to identify the presence of a political entrepreneur, and it was noticed a lack of political force. Political flow was affected only by changes within the government. Fragmentation was a major factor for the theme of weakening the agenda formation. Information security was questioned by the respondents pointed out that the main limitation coupled with the lack of training of public servants. In terms of benefits, resource economy is highlighted, followed by improving efficiency. Finally, the discussion about cloud computing needs to advance within the public sphere, whereas the international experience is already far advanced, framing cloud computing as a responsible element for the improvement of processes, services and economy of public resources

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The substantial increase in the number of applications offered through the computer networks, as well as in the volume of traffic forwarded through the network, have hampered to assure adequate service level to users. The Quality of Service (QoS) offer, honoring specified parameters in Service Level Agreements (SLA), established between the service providers and their clients, composes a traditional and extensive computer networks’ research area. Several schemes proposals for the provision of QoS were presented in the last three decades, but the acting scope of these proposals is always limited due to some factors, including the limited development of the network hardware and software, generally belonging to a single manufacturer. The advent of Software Defined Networking (SDN), along with the maturation of its main materialization, the OpenFlow protocol, allowed the decoupling between network hardware and software, through an architecture which provides a control plane and a data plane. This eases the computer networks scenario, allowing that new abstractions are applied in the hardware composing the data plane, through the development of new software pieces which are executed in the control plane. This dissertation investigates the QoS offer through the use and extension of the SDN architecture. Based on the proposal of two new modules, one to perform the data plane monitoring, SDNMon, and the second, MP-ROUTING, developed to determine the use of multiple paths in the forwarding of data referring to a flow, we demonstrated in this work that some QoS metrics specified in the SLAs, such as bandwidth, can be honored. Both modules were implemented and evaluated through a prototype. The evaluation results referring to several aspects of both proposed modules are presented in this dissertation, showing the obtained accuracy of the monitoring module SDNMon and the QoS gains due to the utilization of multiple paths defined by the MP-Routing, when forwarding data flow through the SDN.

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The railroad, from 1870 and on, becomes an usual complaining in the press s and politician elite s speeches, especially because of Natal s geographic isolation. The implantation of two railroads in the capital territory Estrada de Ferro de Natal a Nova Cruz, afterwards part of Great Western Railway Company network, and Estrada de Ferro Central do Rio Grande do Norte had serious implications in the urban environment. While railroad s structures were already consolidated, other transportation mechanisms were being implanted in the first decades of the 20th century, such as trams lines, which, by the way, was a transport modal that also used rails as a dislocation meaning. Considering these questions, we may ask: how come railroads and tramways demands, roads and buildings had influenced the internal organization of Natal? We work with the general hypothesis that the influence of technical networks, composed by tramways and railroads, over Natal s urban space happened in a diversified way, sometimes consolidating social aspects in certain areas, sometimes improving the occupation of others. The impact over the city s territory also happens in a diversified way between the buildings/railroad s complexes and the pathways. The different scale of the train in comparison to the trams velocity, size, noise level, flow, among others is also a cause to the different consequences in urban environment. The main objective of this work is to understand the role of circulation technical networks in the construction process of urban space in Natal, as a way to contribute to the urban historiography about the subject. The time frame adopted, between 1881 and 1937, marks the time path of railroads and tramways in Rio Grande do Norte: 1881 is the year of railroad s first section inauguration from Natal to São José do Mipibu as well of the railroad complex in the Republic Square in Natal; the year of 1937 marks the beginning of tramways declination process in the city. At this time railroads and tramways had to face more intensively the competition of motor vehicles. The theory reference adopted is based on concepts and analysis of authors, such as Flávio Villaça and Roberto Lobato Corrêa references to the concepts of urban structure , localization and accessibility and Gabriel Dupuy to explain the concept of urban technical networks . These references reveal the conflict of different realities in the urban universe interests and values which is an important factor about the construction of urban space. The information sources used were from two distinctive natures: primary, journals of the time studied and official government reports, and secondary, based on other works about the subject. It was also used by this study iconographic source, especially images from the data base of the research group História da Cidade, do Território e do Urbanismo .