Kinetic Monte Carlo
Mostrando 1-12 de 34 artigos, teses e dissertações.
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1. Alternative Non-Ionic Pathway for Uncatalyzed Prins Cyclization: DFT Approach
Density functional theory calculations (ωB97X-D/6-311++G(d,p)) are employed to investigate an alternative pathway for Prins-like cyclization. Although strong acids usually catalyze this reaction, 4-amino-1,3-dioxanes are rapidly obtained in high yields without catalyst when benzenamines and acetaldehyde react at low temperatures, in aqueous medium. Consider
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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2. Comportamento crítico da produção de entropia em modelos com dinâmicas estocásticas competitivas / Critical behavior of entropy production in models with competitive stochastic dynamics
We study kinetic phase transitions and the critical behavior of the entropy production in spin models with nearest neighbor interactions subject to two Glauber dynamics, which simulate two thermal baths at different temperatures. In this way, it is assumed that the system corresponds to a continuous time Markov process which obeys the master equation. Thus,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/04/2011
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3. Simulação Monte Carlo de mecanismo de transferência de energia de excitação eletrônica: modelo de Perrin para a supressão estática da luminescência
A software based in the Monte Carlo method has been developed aiming the teaching of the Perrin´s model for static luminescence quenching. This software allows the student to easily simulate the luminescence decays of emissive molecules in the presence of quenching ones. The software named PERRIN was written for FreeBASIC compiler and it can be applied for
Química Nova. Publicado em: 2011
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4. Nonextensive statistical mechanics applied to protein folding problem: kinetics aspects
A reduced (stereo-chemical) model is employed to study kinetic aspects of globular protein folding process, by Monte Carlo simulation. Nonextensive statistical approach is used: transition probability p i j between configurations i → j is given by p i j =[1 +(1 - q)ΔGi j/kB T ]1/(1-q), where q is the nonextensive (Tsallis) parameter. The system model cons
Brazilian Journal of Physics. Publicado em: 2009-08
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5. Kinetic Monte Carlo simulation of the nitridation of the GaAs (100) surfaces
We present, our preliminary results of a systematic theoretical study of the adsorption of N over As-terminated GaAs (100) (2×1) surfaces. We analyzed the changes in the bond-lengths, bond-angles and the energetics involved before and after deposition. Our results show that the N-atoms will prefer the unoccupied sites of the surface, close to the As dimer.
Brazilian Journal of Physics. Publicado em: 2006-06
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6. Finite element-based model for crack propagation in polycrystalline materials
In this paper, we use an extended form of the finite element method to study failure in polycrystalline microstructures. Quasi-static crack propagation is conducted using the extended finite element method (X-FEM) and microstructures are simulated using a kinetic Monte Carlo Potts algorithm. In the X-FEM, the framework of partition of unity is used to enrich
Computational & Applied Mathematics. Publicado em: 2004-12
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7. Kinetic phase transition in the mixed-spin Ising model
In this work we studied a ferromagnetic mixed-spin Ising model including a single ion crystal-field term. The model system consists of two interpenetrating sublattices with spins sigma = 1/2 and S = 1. The spins sigma = 1/2 occupy the sites of one sublattice, their nearest-neighbours are spins S on the other sublattice, and vice versa. The system is in conta
Brazilian Journal of Physics. Publicado em: 2004-06
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8. Wind pressures in framed structures with semi-rigid connections
In the analysis and design of framed structures, the traditional methods are based on the simplified assumption that the joints are completely either pinned or rigid. However, the experimental investigations show that the frame connections present an intermediate behaviour between these two extreme cases. The present work is concerned with the dynamic elasti
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-06
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9. Stereo-hydrophobic potential and topological properties in the protein folding / "Potencial estéreo-hidrofóbico e propriedades topológicas no enovelamento de proteínas".
The understanding of the basic principles of the protein folding process may lead to very important applications. Although all significant aspects of this problem are not yet known, experimental and theoretical results have given important contribution on the subject, as, for instance, about the dominant role of the hydrophobic forces. In order to contribute
Publicado em: 2003
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10. Propriedades eletrônicas e estruturais de defeitos em Bulk e superfície de semicondutores / Electronic and structural properties of bulk and surface defects in semiconductor
As propriedades eletrônicas e estruturais de defeitos em bulk e superfície de semicondutores são estudadas através de cálculos de primeiros princípios. Apresentamos um estudo detalhado para as relaxações e distorções para diferentes estados de carga da vacância em Ge. Nosso principal resultado é que a vacância em Ge não é um sistema de U-negat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/12/1999
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11. Processos de polimerização e transição de colapso em polímeros ramificados. / Polymerization processes and collapse transition of branched polymers.
The phase diagram and the tricritical point of a collapsing lattice animal are studied through an extended series expansion of the isothermal compressibility KT on a square lattice. As a function of the variables x (fugacity) and y = e1/T (T is the reduced temperature), this series KT is investigated using the partial differential approximants technique. The
Publicado em: 1997
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12. Use of Monte Carlo calculations in the study of microtubule subunit kinetics.
GTP-tubulin forms a cap on microtubule ends during aggregation. The bulk of the microtubule is GDP-tubulin. This complicates the usual simple kinetic theory of subunit exchange at microtubule ends to such an extent that Monte Carlo calculations are needed to handle the complications, except in special cases. The Monte Carlo method is introduced here, for thi