973 resultados para exterior domains
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We develop a logarithmic potential theory on Riemann surfaces which generalizes logarithmic potential theory on the complex plane. We show the existence of an equilibrium measure and examine its structure. This leads to a formula for the structure of the equilibrium measure which is new even in the plane. We then use our results to study quadrature domains, Laplacian growth, and Coulomb gas ensembles on Riemann surfaces. We prove that the complement of the support of the equilibrium measure satisfies a quadrature identity. Furthermore, our setup allows us to naturally realize weak solutions of Laplacian growth (for a general time-dependent source) as an evolution of the support of equilibrium measures. When applied to the Riemann sphere this approach unifies the known methods for generating interior and exterior Laplacian growth. We later narrow our focus to a special class of quadrature domains which we call Algebraic Quadrature Domains. We show that many of the properties of quadrature domains generalize to this setting. In particular, the boundary of an Algebraic Quadrature Domain is the inverse image of a planar algebraic curve under a meromorphic function. This makes the study of the topology of Algebraic Quadrature Domains an interesting problem. We briefly investigate this problem and then narrow our focus to the study of the topology of classical quadrature domains. We extend the results of Lee and Makarov and prove (for n ≥ 3) c ≤ 5n-5, where c and n denote the connectivity and degree of a (classical) quadrature domain. At the same time we obtain a new upper bound on the number of isolated points of the algebraic curve corresponding to the boundary and thus a new upper bound on the number of special points. In the final chapter we study Coulomb gas ensembles on Riemann surfaces.
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This thesis outlines the construction of several types of structured integrators for incompressible fluids. We first present a vorticity integrator, which is the Hamiltonian counterpart of the existing Lagrangian-based fluid integrator. We next present a model-reduced variational Eulerian integrator for incompressible fluids, which combines the efficiency gains of dimension reduction, the qualitative robustness to coarse spatial and temporal resolutions of geometric integrators, and the simplicity of homogenized boundary conditions on regular grids to deal with arbitrarily-shaped domains with sub-grid accuracy.
Both these numerical methods involve approximating the Lie group of volume-preserving diffeomorphisms by a finite-dimensional Lie-group and then restricting the resulting variational principle by means of a non-holonomic constraint. Advantages and limitations of this discretization method will be outlined. It will be seen that these derivation techniques are unable to yield symplectic integrators, but that energy conservation is easily obtained, as is a discretized version of Kelvin's circulation theorem.
Finally, we outline the basis of a spectral discrete exterior calculus, which may be a useful element in producing structured numerical methods for fluids in the future.
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1. Teorías y tendencias del comercio internacional: - Introducción. - Teorías de comercio internacional. - Tendencias actuales del comercio internacional. Cuestiones. 2. Política comercial comunitaria: - La nomenclatura arancelaria y el arancel aduanero común europeo. - Determinación del origen de las mercancías. - Valor en aduana de las mercancías. - Medidas de política arancelaria y comercial: franquicias aduaneras, destinos específicos, suspensiones arancelarias, contingentes y límites arancelarios, contingentes cuantitativos y medidas de defensa comercial. - Regulación de los regímenes de importación y exportación. - Regímenes aduaneros económicos: importación temporal, régimenes de perfeccionamiento activo y pasivo, régimen de transformación bajo control aduanero, zonas y depósitos francos, depósitos aduaneros, cuestiones de política comercial comunitaria y problemas de política comercial comunitaria. 3. Fiscalidad internacional: - I.V.A., II.EE. y la exportación. - I.V.A., II.EE. y la importación. - I.V.A. intracomunitario. - Sistema Intrastat. - Impuesto de sociedades, cuestiones de fiscalidad internacional y problemas de fiscalidad del comercio exterior. 4. Contratación internacional: - Introducción. - Incoterms. 5. Ejercicios de comercio exterior.
Resumo:
In this thesis, a collection of novel numerical techniques culminating in a fast, parallel method for the direct numerical simulation of incompressible viscous flows around surfaces immersed in unbounded fluid domains is presented. At the core of all these techniques is the use of the fundamental solutions, or lattice Green’s functions, of discrete operators to solve inhomogeneous elliptic difference equations arising in the discretization of the three-dimensional incompressible Navier-Stokes equations on unbounded regular grids. In addition to automatically enforcing the natural free-space boundary conditions, these new lattice Green’s function techniques facilitate the implementation of robust staggered-Cartesian-grid flow solvers with efficient nodal distributions and fast multipole methods. The provable conservation and stability properties of the appropriately combined discretization and solution techniques ensure robust numerical solutions. Numerical experiments on thin vortex rings, low-aspect-ratio flat plates, and spheres are used verify the accuracy, physical fidelity, and computational efficiency of the present formulations.
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Trabajo Final de Grado: Fiscalidad Indirecta y Comercio Exterior. Idioma: Español
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En este trabajo, se estudia la balanza comercial de dos formas. La primera será un análisis general a partir de la entrada de España en la Unión Europea donde se habla de la orientación comercial, de los bienes exportados e importados, del déficit comercial español…. En la segunda forma, centrando el trabajo en ella, se analiza la balanza comercial desde una perspectiva tecnológica, estudiando la evolución de la competitividad española según el contenido tecnológico de sus flujos comerciales.
Resumo:
El presente trabajo realiza un análisis de las Asociaciones Estratégicas de la Unión Europea. Se tratan de un instrumento de política exterior de la Unión, para hacer frente al nuevo orden mundial. Por ello, el trabajo presenta el sistema internacional actual al que se enfrenta la Unión, analiza las Asociaciones Estratégicas (características, funciones y límites) y realiza un breve análisis de los 10 socios estratégicos con quienes se han establecido dichas asociaciones. El trabajo está redactado en castellano.
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Fecha: 7-7-1971. Unidad de instalación, Carpeta Rectorado H-1. 1 recorte de prensa
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Compostos carbonílicos representam uma das principais classes de poluentes atmosféricos e são frequentemente reportados em estudos de poluição atmosférica de interiores. São emitidos para a atmosfera a partir de uma variedade de fontes naturais e antropogênicas. Em projeto empreendido em 2011 pela Secretaria de Estado de Educação do Estado do Rio de Janeiro,foi implementada a climatização em todas as salas de aula de todas as escolas da rede pública estadual. A escala de exposição de ocupantes à climatização, em salas de aula, não apresenta precedentes em nosso estado e representa uma tendência de todo o país. Como é um projeto recente, não há dados a respeito da qualidade do ar interior nesses ambientes e, portanto, das consequências na saúde dos ocupantes. Os procedimentos foram baseados na metodologia TO-11A da U.S.EPA. A técnica de amostragem foi por via seca com reação química, empregando-se cartuchos de sílica revestidos de octadecil (SiO2-C18) impregnados com 2,4-dinitrofenilhidrazina. As carbonilas foram analisados através de Cromatografia Líquida de Alta Eficiência com detecção por UV. Foram encontradas concentrações de formaldeído na faixa de 3,59 a 26,62 μg m-3 (interior) e 0,74 a 23,47 μg m-3 (exterior), acetaldeído na faixa de 0,19 a 259,47 μg m-3 (interior) e 1,19 a 127,51 μg m-3 (exterior), acetona+acroleína na faixa de 0,00 a 48,45 μg m-3 (interior) e 0,00 a 37,00 μg m-3 (exterior). Os valores encontrados geralmente não ultrapassaram os limites determinados por organismos internacionais