Wave Equations
Mostrando 37-48 de 144 artigos, teses e dissertações.
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37. Modeling of electromagnetic waves propagation in four-level two-electron atomic systems governed by Pauli Exclusion Principle using the TLM method
This paper presents a computational model of electrons dynamics and gain in four-level two-electron atomic systems. These systems, submitted to an electromagnetic wave, are governed by Pauli Exclusion Principle and they are modeled using the Time-Domain Transmission Line Matrix (TLM) method with the symmetrical condensed node (SCN) with novel voltage sources
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2012-06
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38. Exact travelling wave solutions for some nonlinear (N+1)-dimensional evolution equations
In this paper, we implement the tanh-coth function method to construct the travelling wave solutions for (N + 1)-dimensional nonlinear evolution equations. Four models, namely the (N + 1)-dimensional generalized Boussinesq equation, (N + 1)-dimensional sine-cosine-Gordon equation, (N + 1)-double sinh-Gordon equation and (N + 1)-sinh-cosinh-Gordon equation, a
Comput. Appl. Math.. Publicado em: 2012
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39. Cota de inundação e recorrência para a enseada do Itapocorói e praia de Morro dos Conventos, Santa Catarina
The goal of this study is to determine the inundation levels at Ensenada do Itapocorói and Morro dos Conventos beaches, located in Santa Catarina State. This was accomplished through the calculation of the inundation level as the sum of astronomical and meteorological tides and wave run-up. The database for this study included -60 years of hourly waves and
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012
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40. The transcendence of time in the epistemology of observation from a phenomenological standpoint
In this article I deal with time as a notion of epistemological content associated though with the notion of a subjective consciousness co-constitutive of physical reality. In this phenomenologically grounded approach I attempt to establish a 'metaphysical' aspect of time, within a strictly epistemological context, in the sense of an underlying absolute subj
Manuscrito. Publicado em: 2011-12
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41. Coherence–incoherence transition in nonlinear wave interactions
In this paper we analyze the transition from coherent to incoherent wave dynamics in a broad-band triplet interaction, where, in contrast to previous models, wave vector selection rules are imposed on the nonlinear terms of the governing equations. As a general rule, nonlinear terms induce coherence via a phase-locking process. However, wave vector spread al
Publicado em: 2011
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42. Equações de onda eletromagnéticas em espaços-tempo curvos / Electromagnetic wave equations in curved spacetimes
Este trabalho tem como um dos objetivos centrais considerar as equações de onda eletromagnéticas que estão envolvidas nas estruturas de curvatura dos formalismos espinoriais de Infeld e van der Waerden para a Relatividade Geral. Equações de onda para fótons com fontes que portam um caráter geométrico emergem no contexto de um dos formalismos e desem
Publicado em: 2011
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43. A study of axi-symmetric waves through an isotropic thermoelastic diffusive medium
The paper deals with the propagation of axial symmetric cylindrical surface waves in a cylindrical bore through a homogeneous isotropic thermoelastic diffusive medium of infinite extent. The three theories of thermoelasticity namely, Coupled Thermoelasticity (CT), Lord and Shulman (L-S) and Green and Lindsay (G-L) are used to study the problem. The frequency
Computational & Applied Mathematics. Publicado em: 2011
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44. Equações de onda para grávitons com fontes eletromagnéticas em espaços curvos sem torção / Wave equations for gravitons with electromagnetic sources in curved spacetimes without torsion
Os formalismos espinoriais de Infeld e van der Waerden são utilizados para descrever a estrutura de curvaturas espaço-temporais da Relatividade Geral. São apresentados os contextos métricos dé cada formalismo assim como o comportamento de seus objetos básicos sob transformações de calibre de Weyl. O desdobramento de curvaturas em partes puramente gra
Publicado em: 2011
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45. Generation of gravitational waves in cosmological phase transition from quark-hadron / Geração de ondas gravitacionais na transição de fase cosmológica quark-hádron
Gravitational waves are possibly the only direct evidence to study the Early Universe in times preceding the matter-radiation decoupling. The future launch of LISA (Laser Interferometer Space Antenna) will possibly provide a precise instrument for measuring this radiation. In this work we calculate the gravitational wave background produced by the quark-hadr
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/10/2010
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46. Evaluation of nacelle drag using Computational Fluid Dynamics
Abstract: Thrust and drag components must be defined and properly accounted in order to estimate aircraft performance, and this hard task is particularty essential for propulsion system where drag components are functions of engine operating conditions. The present work describes a numerical method used to calculate the drag in different nacelles, long and s
J. Aerosp. Technol. Manag.. Publicado em: 2010-08
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47. A new particle-like method for high-speed flows with chemical non-equilibrium
Abstract: The present work is concerned with the numerical simulation of hypersonic blunt body flows with chemical non-equilibrium. New theoretical and numerical formulations for coupling the chemical reaction to the fluid dynamics are presented and validated. The fluid dynamics is defined for a stationary unstructured mesh and the chemical reaction process
J. Aerosp. Technol. Manag.. Publicado em: 2010-04
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48. Equações de ondas com condições de fronteira da acustica / Wave equations with acoustic boundary conditions
Neste trabalho estudamos a resolubilidade de alguns problemas de valores iniciais e de fronteira, envolvendo equações de ondas com Condições de Fronteira da Acústica. Inicialmente, provamos a existência e unicidade de solução para dois problemas com a formulação clássica, introduzida por Beale e Rosencrans [5] (considerando que a fronteira é loca
Publicado em: 2010