Molecular Dynamic Simulation
Mostrando 1-12 de 54 artigos, teses e dissertações.
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1. Pressure-induced Structures and Structural Evolution in Iron
Molecular-dynamic simulations have been used to study the structure evolution in iron melts rapidly cooled under different pressures. An extreme cooling rate (4×1012K/s) was adopted in the cooling process. The simulation results show that at the ambient pressure, martensitic transformation happened. However, at a pressure of 1.4GPa, the system passes from b
Mat. Res.. Publicado em: 17/11/2015
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2. Simulações de líquidos super-resfriados via dinâmica molecular
This work presents the study of two models of glass-forming liquids using molecular dynamics simulations. The first model aims to analyze the effects on glassy dynamics which allow the enhancement of the glass formability on metallic glass formers. The Pd45Ni55 binary alloy and the Pd35Ni55Pt10 ternary one are modeled via the Embedded Atom method interaction
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/10/2012
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3. Stability analysis of carbon nanotubes based on a novel beam model and its comparison with Sanders shell model and molecular dynamics simulations
We study the effects of small-scale parameter on the buckling loads and strains of nanobeams, based on nonlocal Timoshenko beam model. However, the lack of higherorder boundary conditions leads to inconsistencies in critical buckling loads. In this paper, we apply a novel approach based on nonlocal Timoshenko kinematics, strain gradient approach and variatio
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2012-06
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4. Investigating the spontaneous formation of SDS micelle in aqueous solution using a coarse-grained force field
A 1µs Molecular Dynamic simulation was performed with a realistic model system of Sodium Dodecyl Sulfate (SDS) micelles in aqueous solution, comprising of 360 DS-, 360 Na+ and 90000 water particles. After 300 ns three different micellar shapes and sizes 41, 68 and 95 monomers, were observed. The process led to stabilization in the total number of SDS cluste
Química Nova. Publicado em: 2012
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5. Modelagem e simulação de reatores autoclave para produção de PEBD
The low density polyethylene (LDPE) is a thermoplastic resin manufactured by high pressure processes, with autoclave or tubular type reactors. The present scenario is of growing demand for LDPE produced at competitive costs, through high performance and capacity plants, so that the process and product development becomes a key factor for the producers, and p
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012
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6. Simulação do processo de adsorção psa para separação da mistura etanol-água / Simulation of the adsorption process psa for separation of ethanol-water mixtures
One of the problems with ethanol production is the high energy cost which is associated with the separation of ethanol due to of excess water and the existence of an azeotrope in the mixture ethanol-water, by conventional distillation the mixture can be separated up to 95% weight. Currently, there is great interest in the development of technological process
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/07/2011
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7. Development of a supercritical extraction pilot plant for upgrading of heavy oils and study of the asphaltene aggregation process / Desenvolvimento de uma planta piloto de desasfaltação supercritica para valoração de petroleos pesados e estudo do processo de agregação dos asfaltenos
Alphaltenes are complex aromatic macro-cycle molecules, with a molecular structure that varies depending on the origin of the crude oil. Apart from heir contribution to the properties of petroleum, the study of the asphaltic fraction asbecome more important, due to the problems encountered during petroleum Pro cessing caused by asphaltene precipitation, whic
Publicado em: 2009
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8. Simulation of styrene polymerization reactors: kinetic and thermodynamic modeling
A mathematical model for the free radical polymerization of styrene is developed to predict the steady-state and dynamic behavior of a continuous process. Special emphasis is given for the kinetic and thermodynamic models, where the most sensitive parameters were estimated using data from an industrial plant. The thermodynamic model is based on a cubic equat
Brazilian Journal of Chemical Engineering. Publicado em: 2008-06
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9. Investigação experimental e computacional da polimerização via radical livre controlada em presença de radicais nitroxido (NMRP) utilizando-se iniciadores difuncionais / Experimental and computational investigation of nitroxide mediated radical polymerization (NMRP) using di-functional initiators
Controlled/Living Free Radical Polymerization (LFRP) is one of the most important techniques for production of polymeric materials with good control of the microstructure (e.g., narrow molecular weight distributions). Such properties can also be achieved via ionic polymerizations, but being a free radical polymerization process, LFRP is much less sensitive t
Publicado em: 2008
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10. Efeitos anarmônicos e transições de fase em Pb1xLaxTiO3: estudo por espalhamento Raman dos efeitos de substituição catiônica, temperatura e pressão hidrostática
In this work were studied eects of cationic substitution, hydrostatic pressure and temperature on the phonon spectra of PLT samples, Pb1xLaxTiO3 (PLT), using Raman scattering technique. The samples having La concentration x= 0, 2.5, 5, 10, 15 and 20%, were prepared by the classic powder mixture of oxides. Other complementary techniques were used to character
Publicado em: 2008
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11. Temperature dependent molecular dynamic simulation of friction
In this work we present a molecular dynamics simulation of a FFM experiment. The tip-sample interaction is studied by varying the normal force in the tip and the temperature of the surface. The friction force, cA, at zero load and the friction coefficient, m, were obtained. Our results strongly support the idea that the effective contact area, A, decreases w
Brazilian Journal of Physics. Publicado em: 2006-09
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12. Effects of molecular rovibrational states and surface topologies for molecule-surface interaction: chemisorption dynamics of D2 collision with rigid Ni surfaces
A quasiclassical and micro-canonical molecular dynamic simulation techniques have been applied for D2(v, j) + Ni-surface collision systems. Dissociative adsorptions of a D2 molecule on the rigid low index (100), (110) and (111), surfaces of the nickel are investigated to understand the effects of the different surfaces, impact sites and the initial rovibrati
Brazilian Journal of Physics. Publicado em: 2006-09