مقالات رزومه شادی اسماعیلی

The mechanical properties of carbon polycrystalline materials are crucial because they determine how the material responds to external forces, such as stress and strain, and environmental conditions.  By investigating the mechanical properties of carbon polycrystalline materials, researchers can develop insights into their strength, ductility, hardness, and other characteristics, which are vital for their practical applications in industries such as manufacturing, construction, and materials science. Molecular dynamics techniques enable the examination of various polycrystalline configurations and the assessment of their effectiveness. The present study investigates the effects of temperature on the mechanical properties of Carbon polycrystalline. The results show that the ultimate strength and Young’s modulus of the simulated polycrystal are 64.553 Gpa and 355.284 GPa, respectively. Also, the results showed that with increasing temperature to 320 K, Young’s modulus and ultimate strength of carbon polycrystalline increase to 363.185 and 69.417 GPa, respectively.  With a further increasing the temperature to 350 k, these parameters decrease to 349.909 and 63.047 GPa. The observed increase in these parameters at lower temperatures may be attributed to the increased atomic mobility of the samples resulting from the initial temperature enlargement. The simulation results are expected to help further understand the influence of temperature on the mechanical properties of carbon polycrystalline materials.

Solid materials that contain holes in their structure are generally defined as porous materials. Porosity is obtained by dividing the volume of pores by the total volume of the material. Porous materials are a new category of materials that have attracted the attention of scientists and different industries due to their special mechanical properties, such as definable strength and density. These materials have been attracted due to various applications in molecular separation, heterogeneous catalysis, absorption technology or light and electronics technology. This research aims to investigate the effects of an electric field on the mechanical properties of a silicon-doped carbon matrix with 10% porosity. The mechanical properties investigated in this research include Young's modulus and ultimate strength, obtained using the molecular dynamics (MD) simulation method and LAMMPS comprehensive software. The results revealed that the ultimate strength and Young’s modulus of silicon-doped nanoporous carbon matrix converged to 69.4014 GPa and 200.192GPa, respectively. In the following, the mechanical strength in simulated samples decreases with increasing the electric field magnitude. Numerically, by increasing the electric field from 0.2 to 0.5 V/Å, the ultimate strength and Young’s modulus of silicon-doped nanoporous carbon matrix decrease from 65.83 and 191.022 GPa to 57.81 and 167.18 GPa

In this study, the effect of different substitutions (Eu, Ce, Al, and Bi) on the structural and magnetic properties of Fe3O4 is investigated. All samples were synthesized with the cathodic electrochemical deposition method. The structural properties and surface morphology are investigated by  XRD and FESEM analyses. Structural analysis of the samples showed the formation of a single-phase structure with an Fd-3m space group. The results also showed that the lattice constant and the cell volume increase by increasing the substituted ion's radius. The results of surface morphology of the samples also showed that with increasing substituted ion radius, the average diameter of the samples increases. For BiFe2O4, EuFe2O4, CeFe2O4, and AlFe2O4 samples, the mean diameter was obtained at 50.038 (±13.60)nm, 47.95 (±9.62)nm, 36.06 (±8.29)nm, and 45.72 (±5.39)nm, respectively. And, the magnetic properties of the samples were investigated by VSM analysis. The study of the magnetic properties of the samples shows the superparamagnetic behavior for all samples. Also, the results show that substituting Fe ions with larger radii ions leads to a decrease in saturation magnetization (Ms) and residual magnetization (Mr).