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The deformation of polycrystal grains is hampered by the action of nearby grains. Their influence on structural changes under uniaxial compression has been studied using molecular dynamics simulations. [100] single crystals were studied as a characteristic orientation of growth grains. This orientation is most found in products obtained by electron-beam surfacing of aluminum bronze. The patterns of slip, twinning, and the formation of deformation domains are traced depending on the conditions for limiting the shear towards the lateral faces of the sample. Shown, that the shear limitation and the complication of the stress tensor contribute to the earlier development of twinning. [ABSTRACT FROM AUTHOR]

The purpose of this study was to simulate Nickel oxide (NiO) and water (H2O) molecules, by observing their molecular characteristics and dynamics in the form of essential parameters, such as kinetic, potential and total energy, including its effect on the division of H2O into hydrogen gas molecules (H2).Simulations were carried out by modeling the molecular structures using Hyperchem Professional Release 8.0 and ChemDraw Ultra program, such as the 2-dimensional analysis with ChemDraw Ultra and 3-dimensional projections made using ChemBio. The molecular dynamics between (NiO) and Water (H2O) molecules were carried out using the Hyperchem program and 3-dimensional visualization displays. The molecular structure of NiO and H2O, as potential and kinetic energy increases, makes the H2O molecules to become unstable which leads to the splitting of the H-atomic body. The results showed that display energy significantly decreased for some time, due to the breakdown of molecular bonds facilitated by the increase in kinetic energy. Therefore, a high kinetic energy, leads to an increase in molecular movement. Furthermore, the maximum total energy versustime on H2O with and without NiO was 7.3kcal/mol and 4.55kcal/mol, respectively at 0.1 pswas obtained. Principally, important parameters, such as kinetic, potential and total energy, including temperature, time and its effect on the division of H2O into hydrogen (H2) molecules between a molecule of nickel oxide and water, indicate a high usability of nickel oxide in the catalytic form. [ABSTRACT FROM AUTHOR]

In the present study, molecular dynamic simulations of high-velocity impact of 3C-SiC nanorod in a wide range of velocities with a rigid wall, were performed. The influence of different types of artificial defects in the nanorod on the ability to accumulate impact energy was investigated. [ABSTRACT FROM AUTHOR]

A molecular dynamics simulation of the self-diffusion of thorium cations in ThO2 nanocrystals with a free surface is conducted. It is shown that a vacancy in the bulk of a crystal initiates a complex collective movement of cations, in which the interstitial positions surrounding the vacancy are involved. The diffusion coefficients of cations in the temperature range are calculated. The effective activation energy of diffusion is ED = (7.6 ± 0.7) eV. [ABSTRACT FROM AUTHOR]

Due to ultrathin nanostructure, the highest specific surface area, the exceptional surface to volume ratio, 2-D materials exhibit diverse and dramatically improved properties. These properties are further dependent on their shapes and sizes. Among the 2-D materials, although lots of investigations on graphene have been carried out and are still going on, borophene nanotube has not received much attention so far for the analysis of mechanical properties. The present study focuses on molecular dynamic simulation with Stillinger-Weber potential for borophene nanotube to explore and evaluate its mechanical properties. The mechanical properties, such as yield strength and modulus of elasticity, of borophene nanotube at different strain rate have been evaluated. It is found that the modulus of elasticity decreases with the increase of strain rate during tension where the tensile loading is applied along the axial direction of the tube. Yield strength and modulus of elasticity decrease with the increase of temperature. The effects of the diameter and percentage of defect on the mechanical properties of borophene nanotube have also been investigated during tension. Mechanical properties evaluated in the present study are found to be much better in comparison with those of other 2-D materials. The obtained results are expected to be useful for near-future technical applications. [ABSTRACT FROM AUTHOR]

The research of molecular dynamic simulation by classical mechanic method on Mg-xZn has been done. The goal of this research is to find out Mg-xZn's structure after it's been given temperature treatment and how it's mechanical properties. Potential which been used are Embedded Atomic Method (EAM), Stillinger and Weber (SW), and Lennard- Jones (LJ). The structure of Mg-xZn before temperature treatment was HCP. Mechanical properties which observed are elastic constant and bulk modulus. Temperature treatment simulation was conducted before mechanical properties simulation is done by doing heating- cooling process simulation on the fixed material's structure. Elastic constant value on Mg-xZn which has low percentage of Zn is higher than the one which has high percentage. Elastic constant value from melting treatment is higher than sintering treatment. Elastic constant that its value is approaching good mechanical properties is sintering treatment Mg-7Zn which has C11, C12, and C44 is 34,05 GPa, 12,79 GPa, and 1,33 GPa respectively. [ABSTRACT FROM AUTHOR]

A molecular dynamics simulation of helium diffusion in solid CaF2, SrF2, and BaF2 was carried out using the empirical pair potentials reproducing the experimental strong binding of helium to cations in these crystals. The model diffusion coefficients and activation energies are determined. [ABSTRACT FROM AUTHOR]

With a biodegradation rate exceeding 90%, TMPTO, a polyol ester, is used as a base oil for bio-lubricant. Its excellent physicochemical properties, made TMPTO based bio-lubricants applied as metalworking fluids such as in hydraulics, chains and machines. In this study, TMPTO is derived from chemical reactions between Trimethylolpropane (TMP) and the methyl ester which synthesized from plant oils such as palm and Jatropha curcas. With hBN nanoparticles addition, it is expected improving its heat transfer capability. This study is predicting the thermal conductivity of TMPTO with various hBN nanoparticles concentration using the molecular dynamics simulation method. The thermal conductivity value is computed using Green-Kubo formalism, and it is applied to compute the heat flux vector based on a contribution from atoms in the specified group. Based on simulations, we get the best thermal conductivity value around 0.255 – 0.375 W/mK, which performed by TPMTO with a 0.4% hBN addition. [ABSTRACT FROM AUTHOR]