873 resultados para local authorities


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Self-trapping, stopping, and absorption of an ultrashort ultraintense linearly polarized laser pulse in a finite plasma slab of near-critical density is investigated by particle-in-cell simulation. As in the underdense plasma, an electron cavity is created by the pressure of the transmitted part of the light pulse and it traps the latter. Since the background plasma is at near-critical density, no wake plasma oscillation is created. The propagating self-trapped light rapidly comes to a stop inside the slab. Subsequent ion Coulomb explosion of the stopped cavity leads to explosive expulsion of its ions and formation of an extended channel having extremely low plasma density. The energetic Coulomb-exploded ions form shock layers of high density and temperature at the channel boundary. In contrast to a propagating pulse in a lower density plasma, here the energy of the trapped light is deposited onto a stationary and highly localized region of the plasma. This highly localized energy-deposition process can be relevant to the fast ignition scheme of inertial fusion.

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There is a wonderful conjecture of Bloch and Kato that generalizes both the analytic Class Number Formula and the Birch and Swinnerton-Dyer conjecture. The conjecture itself was generalized by Fukaya and Kato to an equivariant formulation. In this thesis, I provide a new proof for the equivariant local Tamagawa number conjecture in the case of Tate motives for unramified fields, using Iwasawa theory and (φ,Γ)-modules, and provide some work towards extending the proof to tamely ramified fields.

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O presente trabalho se propõe fazer uma aproximação aos estudos sobre a tradicionalmente chamada Feira de São Cristóvão, levando em consideração a relação entre os agentes partícipes e a dinâmica no espaço. O objetivo é compreender melhor a força que move os atores no sentido da mudança da forma da feira para a forma do Centro Luiz Gonzaga de Tradições Nordestinas (CLGTN), e assim me aproximar da seguinte questão: Por que uma forma de comércio como a modelada na Feira de São Cristóvão, popularmente conhecida como feira dos paraíbas, sobrevive à força das mudanças operadas no ramo, dando lugar aos sofistificados shopping-centers? Para isso, faço uma aproximação ao estado de arte da pesquisa na área com base nas seguintes categorias de análise: a Feira como forma de produção do espaço e a relação Forma-Conteúdo, a relação espaço-identidade na feira e a relação entre agentes internos e externos no Espaço. Vendo a migração como movimento responsável pela constituição de um espaço social e territorialmente diferenciado do nordestino na cidade do Rio de Janeiro, é por ela que inicio a exposição. Esta se continua com a análise dos trabalhos escolhidos para estudo, via as categorias indicadas e, com um capítulo no qual procuro repensar a feira a partir da relação global-local que vem referenciando as reflexões acumuladas na área do urbano a partir da segunda metade do século XX. Por fim, concluo observando que a permanência da feira se deve a um duplo movimento de resistência-absorção que, se redefinindo no tempo e no espaço, não consegue, entretanto, apagar os traços da tradição que lhe deu origem.

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El presente Trabajo de Fin de Grado nos ofrece la posibilidad de profundizar en aspectos relacionados con la administración pública,tomando como base la información presupuestaria y financiera de la Entidad Local Sarriko 1. en el período 2010-2013. Se analizará el volumen de gasto e ingreso liquidado, su distribución funcional y económica. Además se diagnosticará su situación presupuestaria y financiera actual, las causas que la han llevado a esta situación y en la medida de lo posible determinar escenarios de situación futuros.Por otro lado, se aborda el tema de la Estabilidad Presupuestaria, así como el cálculo de dicha variable.

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Resumen (ESPAÑOL) En el presente trabajo se ha tratado de analizar la evolución, tanto del concepto de Desarrollo Sostenible, como de la herramienta Agenda 21 Local, verificando la creciente preocupación que se está extendiendo en la ciudadanía, en las instituciones y en las empresas, así como la irreversibilidad de la mayoría de los resultados alcanzados. En este marco, se han estudiado los casos concretos de la implantación de la Agenda 21 Local en Europa, España, Euskadi y Getxo, por ser este último el municipio en el que resido. Con este estudio, se confirma la hipótesis de que, aunque en la implantación de la Agenda 21 Local se aprecia un esfuerzo realizado notable, queda todavía mucho camino por recorrer en la senda hacia la sostenibilidad.

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A real-time, in situ fixing method by use of heating with a CO2 laser beam is suggested for thermal fixing of a small local hologram in the bulk of a Fe:LiNbO3 photorefractive crystal. For heating up to 100 degrees C-200 degrees C a volume with a shape similar to that of the laser beam a heat-guiding technique is developed. On the basis of the heat-transfer equations, different heating modes with or without metal absorbers for heat guiding-obtained by use of a continuous or pulsed laser beam are analyzed. The optimal mode may be pulsed heating with absorbers. On this basis experiments have been designed and demonstrated. It is seen that the fixing process with CO2 laser beam is short compared with the process by use of an oven, and the fixing efficiency is quite high. (C) 1998 Optical Society of America.

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With the installation by the Pacific Electric Railway of a bus system in Pasadena to supplant most of its trolley lines, the problem of the comparison of the costs of the two systems naturally presented itself. The study here undertaken was originally started as just a comparison of the motor bus and Birney Safety Car, but as the work progressed it seemed advisable to include the trolley bus as well - a method of transportation that is comparatively new as far as development is concerned, but which seems to be finding increasing favor in the East.

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A fast and reliable phase unwrapping (PhU) algorithm, based on the local quality-guided fitting plane, is presented. Its framework depends on the basic plane-approximated assumption for phase values of local pixels and on the phase derivative variance (PDV) quality map. Compared with other existing popular unwrapping algorithms, the proposed algorithm demonstrated improved robustness and immunity to strong noise and high phase variations, given that the plane assumption for local phase is reasonably satisfied. Its effectiveness is demonstrated by computer-simulated and experimental results.

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Based on the two-dimensional coupled-wave theory, the wavefront conversion between cylindrical and plane waves by local volume holograms recorded at 632.8 nm and reconstructed at 800 nm is investigated. The proposed model can realize the 90 degrees holographic readout at a different readout wavelength. The analytical integral solutions for the amplitudes of the space harmonics of the field inside the transmission geometry are presented. The values of the off-Bragg parameter at the reconstructed process and the diffracted beam's amplitude distribution are analysed. In addition, the dependences of diffraction efficiency on the focal length of the recording cylindrical wave and on the geometrical dimensions of the grating are discussed. Furthermore, the focusing properties of this photorefractive holographic cylindrical lens are analysed.