Nonlinear Evolution Equations
Mostrando 1-12 de 27 artigos, teses e dissertações.
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1. Scaling Symmetries and Conservation Laws for Variable-coefficients Nonlinear Dispersive Equations
RESUMO. Simetrias de escala surgem em diferentes ramos da física e abordagens baseadas em simetria são poderosas ferramentas para estudar modelos invariantes por escala, pois podem fornecer leis de conservação que não são óbvias por inspeção. Nessa perspectiva, a classe de equações dispersivas não-lineares com coeficientes variáveis vc K ( m ,
TEMA (São Carlos). Publicado em: 13/12/2019
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2. Damage based constitutive model for predicting the performance degradation of concrete
An anisotropic elastic-damage coupled constitutive model for plain concrete is developed, which describes the concrete performance degradation. The damage variable, related to the surface density of micro-cracks and micro-voids, and represented by a second order tensor, is governed by the principal tension strain components. For adequately describing the par
Lat. Am. j. solids struct.. Publicado em: 2014-11
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3. 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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4. Numerical solution of coupled mass and energy balances during osmotic microwave dehydration
The mass and energy transfer during osmotic microwave drying (OD-MWD) process was studied theoretically by modeling and numerical simulation. With the aim to describe the transport phenomena that occurs during the combined dehydration process, the mass and energy microscopic balances were solved. An osmotic-diffusional model was used for osmotic dehydration
Comput. Appl. Math.. Publicado em: 2012
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5. Fluxos de curvatura, soluções que se anulam em tempo finito e comportamento assintótico / Curvature flows, solutions quenching in finite time and asymptotic behavior
Neste trabalho apresentamos resultados sobre o fluxo de curvatura média, Gauss e harmônica de superfícies de revolução sujeito a condições de fronteira do tipo Dirichlet, Neumann ou singular. Soluções de alguns dos fluxos de curvatura com alguma destas condições de fronteira ou se anulam em tempo finito ou existem globalmente no tempo convergindo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/09/2011
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6. Formação de sólitons em condensados de Bose-Einstein e em meios ópticos / Formation of solitons in Bose-Einstein condensates and in photorefractive media
Different kinds of solitons have already been observed in various nonlinear optical media, and their behavior has been explained in the frameworks of such mathematical models as the nonlinear Schrödinger and generalized nonlinear Shrödinger equations for different dimensions and geometries. However, there are situations when many solitons are generated so
Publicado em: 2010
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7. Waves in nuclear matter / Ondas na matéria nuclear
Assuming that nuclear matter can be treated as a perfect fluid, we study the propagation of perturbations in the baryon density. The equation of state is derived from a relativistic mean field model, which is a variant of the non-linear Walecka model. The expansion of the Euler and continuity equations of relativistic hydrodynamics around equilibrium configu
Publicado em: 2009
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8. MODELOS DE DIMENSÃO REDUZIDA PARA ANÁLISE DAS OSCILAÇÕES NÃO-LINEARES E ESTABILIDADE DE CASCAS CILÍNDRICAS / LOW DIMENSIONAL MODELS FOR NONLINEAR VIBRATION ANALYSIS AND STABILITY OF CYLINDRICAL SHELLS.
The nonlinear vibrations and stability of a fluid-filled cylindrical shell is investigated using reduced order models. First, the nonlinear equations of motion of the cylindrical shell are deduced based on the expressions for the potential and kinetic energy, which are obtained using Donnell shallow shell theory. The internal fluid is considered to be irrota
Publicado em: 2008
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9. "Simulations of 3D two-phase flows using adaptive methods and phase field models" / "Simulações de escoamentos tridimensionais bifásicos empregando métodos adaptativos e modelos de campo fase"
This is the first work that introduces 3D fully adaptive simulations for a phase field model of an incompressible fluid with matched densities and variable viscosity, known as Model H. Solving numerically the equations of this model in meshes locally refined with AMR technique, we simulate computationally tridimensional two-phase flows. Phase field models of
Publicado em: 2007
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10. Non-Linear electron mobility in n-doped III-Nitrides
A theoretical study of the mobility of n-doped III-Nitrides in wurtzite phase is reported. We have determined the nonequilibrium thermodynamic state of the bulk n-InN, n-GaN, and n-AlN systems - driven far away from equilibrium by a strong electric field - in the steady state, which follows after a very fast transient. For this we solve the set of coupled no
Brazilian Journal of Physics. Publicado em: 2006-06
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11. Formação de estruturas em cosmologia no regime não-linear: uma aproximação por sistemas dinâmicos
The formation of large scale structure is an outstanding problem in Cosmology. It is a consensus that the observed variety of structures such as galaxies and clusters of galaxies have originated from small fluctuations of the cosmic fluid possibly generated during the inflationary epoch-in the matter dominated era. The early stages of evolution of these fluc
Publicado em: 2006
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12. Estudo do acoplamento efetivo entre duas particulas brownianas quanticas / Study of effective coupling between two quantum Brownian particles
We use the system-plus-reservoir model to study the dynamics of a system of two particles that interact with a heat bath in thermal equilibrium, but do not interact with each other. We present an extension of the bath of oscillators capable of inducing an effective coupling between the brownian particles depending on the choice made to the spectral function
Publicado em: 2006