Vortex Dynamics
Mostrando 13-24 de 47 artigos, teses e dissertações.
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13. Estudo da estabilidade secundária da esteira de um cilindro em oscilação forçada. / Study of secondary stability of the wake of a circular cylinder undergoing forced oscilation.
This thesis presents the investigation of the transition to a three-dimensional flow in the wake of an oscillating circular cylinder. This is the secondary transition of the flow around a circular cylinder, while the primary transition leads to the von Kármán wake. The investigative work is performed in the Reynolds number (Re) range which occurs the secon
Publicado em: 2010
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14. Desenvolvimento de procedimentos de modelagem de interação fluido-estrutura combinando a Teoria de Vigas de Cosserat e a metologia de fronteira imersa / Developing procedures for modeling fluid-structure interaction by combining the Cosserat beams theory and immersed boundary methodology
A presente tese descreve o trabalho de pesquisa realizado, com o objetivo de desenvolver, implementar e avaliar um procedimento de modelagem tridimensional de fenômenos fluidoestruturais que envolvem estruturas esbeltas, tais como vigas, barras e cabos. A nova abordagem adotada consiste na combinação da teoria de vigas de Cosserat aplicada a estruturas es
Publicado em: 2010
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15. Effect of an columnar defect on vortex configuration in a superconducting mesoscopic sample
In this work we investigate the vortex dynamics in a square mesoscopic superconducting cylinder in the presence of an applied magnetic field parallel to its axis. The rectangular cross-section of the sample is L² and an engineered columnar defect of area d² at the center is taken into account; L = 12ξ(0) for all simulations while d varies discretely from
Brazilian Journal of Physics. Publicado em: 2009-12
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16. Genetic consequences of population subdivision: the marsupial Micoureus paraguayanus (Mammalia: Didelphimorphia) as a case study
Habitat fragmentation may cause population subdivision, affecting genetic variation, leading to heterozygosity loss and increased inbreeding, and contributing to population extinction. However, some genetic models have shown that under some conditions, population subdivision can favor heterozygosity and allelic diversity, and small populations may adapt to i
Zoologia (Curitiba). Publicado em: 2009-12
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17. Unsteady aerodynamic coefficients obtained by a compressible vortex lattice method.
Unsteady solutions for the aerodynamic coefficients of a thin airfoil in compressible subsonic or supersonic flows are studied. The lift, the pitch moment, and pressure coefficients are obtained numerically for the following motions: the indicial response (unit step function) of the airfoil, i.e., a sudden change in the angle of attack; a thin airfoil penetr
Publicado em: 2009
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18. Dinâmica de spins na presença de defeitos em estruturas magnéticas confinadas: aplicações a nanodiscos magnéticos / Spin dynamics in the presence of defects on confined magnetic structures: applications the magnetic nanodisk
Neste trabalho nós investigamos a influência de defeitos artificiais inseridos em nanodiscos magnéticos na dinâmica do núcleo do vórtice. Primeiro consideramos a presença de buracos. A dinâmica foi analisada inicialmente na presença de um buraco e depois na presença de dois buracos. No geral, o núcleo cai no defeito mas, na presença de um único
Publicado em: 2009
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19. Ecologia reprodutiva e análise de viabilidade de uma população do cágado Hydromedusa maximiliani (Testudines, Chelidae) no Parque Estadual Carlos Botelho / Reproduction ecology and population viability analysis of the neotropical freshwater turtle Hydromedusa maximiliani (Testudines, Chelidae) at the Parque Estadual Carlos Botelho, São Paulo, Brazil
The reproductive strategies of Hydromedusa maximiliani at the Carlos Botelho State Park, SP, was verified by X-ray in females and juveniles between September 2007 and December 2008. Throughout the study two reproductive seasons were detected, both beginning in September. From a total of 33 X-rayed females, only 19 showed eggs, and three of them showed eggs i
Publicado em: 2009
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20. O Método da Vorticidade em Partículas para estimar coeficientes aerodinâmicos : uma validação com três pontes brasileiras / The vortex particle method to estimate aerodynamic coefficients : a validation with three brazilian bridges
O presente trabalho tem como objetivo realizar um estudo comparativo entre os três métodos para obtenção das características aerodinâmicas de tabuleiros de pontes: analítico, experimental e numérico. O tema é motivado pelo crescimento das necessidades de conhecimento científico e tecnológico na área de desempenho aerodinâmico de seções típica
Publicado em: 2008
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21. Transição ordem-desordem da matéria de vórtices em supercondutores detectada através do terceiro harmônico da suscetibilidade AC
Although a vortex state, in type II superconductors, has been anticipated more than 50 years ago, a great deal of theoretical and experimental efforts has still been done in an attempt to investigate how the dynamics of these structures depends on external excitations and on the inherent properties of the underlying superconducting material, such as inhomoge
Publicado em: 2008
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22. Pinning of Abrikosov Vorticein MG B IND. 2 addition of NI nanoparticles / Aprisionamento dos Vortices de Abrikosov no MG B IND. 2 atraves da adição de nanoparticulas de NI
Since the discovery of the phenomenon of superconductivity in magnesium diboride (MgB2) in the year 2001, the vortex dynamics in this material has been widely studied, because this phenomenon can cause the destruction of the superconducting state. This study intends to assess the impact on the pinning of vortex and the behavior of the critical current densit
Publicado em: 2008
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23. Propriedades de equilÃbrio e de transporte da matÃria de vÃrtices em nanoestruturas supercondutoras
In the present thesis, we study theoretically the equilibrium properties and dynamics of the vortex matter in two classes of nanostructured superconductors: (i) mesoscopic samples, with dimensions comparable with the penetration depth; and (ii) films with periodic array of artificial traps. In both cases, the vortex lattice symmetry is strongly dependent on
Publicado em: 2007
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24. Estudo dos efeitos das variáveis geométricas no desempenho de ciclones convencionais e filtrantes
Filtering cyclones are pieces of equipment used for separation of suspended solids present in gaseous streams. This equipment consists of the replacement of the metallic conical section by a porous conical section. In this work, through experimental design, it was studied the influence of four geometric variables on the cut diameter, collection efficiency an
Publicado em: 2007