Variational Basis
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Dynamics of rotating non-linear thin-walled composite beams: analysis of modeling uncertainties
In this article a non-linear model for dynamic analysis of rotating thin-walled composite beams is introduced. The theory is deduced in the context of classic variational principles and the finite element method is employed to discretize and furnish a numerical approximation to the motion equations. The model considers shear flexibility as well as non-linear
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012
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2. A DYNAMIC INTERACTION MODEL OF TRACK RAILWAY STRUCTURAL ELEMENTS / UM MODELO DE INTERAÇÃO DINÂMICA ENTRE OS ELEMENTOS ESTRUTURAIS DE UMA VIA FÉRREA
In a railway, the vehicle interacts dynamically with a track superstructure (rails, rail pad and sleepers) and sub-structure (ballast, sub-ballast, sub- grade). Passengers comfort, environmental loading (ground vibration) and frequency of maintenance works of vehicles as well as of the track are deter- mined by the way all the structural elements interact. T
Publicado em: 2006
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3. Electronic excitations by positron impact in Schwinger multichannel method / Excitações eletronicas por impacto de positrons via Metodo Schwinger multicanal
Nesta tese investigamos a modelagem teórica de colisões pósitron-molécula no regime de baixas energias utilizando o método Schwinger multicanal. Nosso objetivo inicial foi sofisticar o procedimento de cálculo do parâmetro de aniquilação¸ Zeff . Esta quantidade é diretamente proporcional a taxa de aniquilação de pósitrons com elétrons da nuvem
Publicado em: 2006
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4. Theoretical innovation and computational experiments in Quantum Monte Carlo / Inovações teoricas e experimentos computacionais em Monte Carlo Quantico
The Hartree-Fock method (HF) is the principal strategy used in theoretical chemistry for electronic structure calculations. Although valuable results can be obtain with HF, this method has deficiencies in the treatment of some systems, which are related mainly with electronic correlation. Several methods were developed, known as "post-Hartree-Fock", in arder
Publicado em: 2005
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5. CONVENTIONAL, HYBRID AND SIMPLIFIED BOUNDARY ELEMENT METHODS / MÉTODOS DE ELEMENTOS DE CONTORNO CONVENCIONAL, HÍBRIDOS E SIMPLIFICADOS
A consolidated, unified formulation of the conventional (CCBEM), hybrid stress (HSBEM), hybrid displacement (HDBEM) and simplified hybrid stress (SHSBEM) boundary element methods is presented. As a counterpart of SHSBEM, the simplified hybrid displacement boundary element method (SHDBEM) is proposed on the basis of the same stress and displacement approximat
Publicado em: 2004
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6. Novos desenvolvimentos e aplicaÃÃes de mÃtodos de quÃmica quÃntica para compostos de coordenaÃÃo com Ãons lantanÃdeos
Theoretical studies on lanthanide compounds were performed, and divided into three parts: (i) generalization of the Linderberg-Seamans equations for an s-p-d-f basis set; (ii) study of the ligand-to-lanthanide ion charge transfer transitions (LMCT) with the ZINDO98 program using the INDO/S semiempirical hamiltonian and (iii) a study of point charge and charg
Publicado em: 2003
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7. Studies of electron-molecule collisions using the Schwinger variational principle with plane waves as a trial basis set
We report elastic differential cross sections (DCS) for the scattering of electron by H2, CH4, C2H4, SiH4, and H2O in the 5 to 20 eV energy range. These cross sections were obtained using the Schwinger variational principle. In our procedures the scattering wave function is expanded as a combination of plane waves. In the present implementation the exchange
Brazilian Journal of Physics. Publicado em: 2000-06
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8. STUDY OF THE HYBRID BOUNDARY ELEMENT METHOD AND THE PROPOSAL OF A SIMPLIFIED FORMULATION / ESTUDO DO MÉTODO HÍBRIDO DOS ELEMENTOS DE CONTORNO E PROPOSTA DE UMA FORMULAÇÃO SIMPLIFICADA / ESTUDIO DEL MÉTODO HÍBRIDO DE LOS ELEMENTOS DE CONTORNO Y PROPUESTA DE UNA FORMULACIÓN SIMPLIFICADA
The hybrid boundary element method was introduced in 1987. Since then, the method has been applied successfully to different problems of elasticity and potential, including time-dependent problems. However, some important aspects of the method have remained open to investigation. This dissertation consists in a threefold contribution, with developments outli
Publicado em: 1999