International Journal of Computational Materials Science and Engineering

COVID-19 is a serious respiratory disease caused by a devastating coronavirus family (2019-nCoV) that has become a global epidemic. It is an infectious virus transmitted by inhalation or contact with the droplet core produced by infected people when they sneeze, cough, and speak. SARS-COV-2 transmission in the air is possible even in a confined space near the infected person. This study examines air conditioners’ effect on the mixed virus and droplets with aerosol disinfectant and gets throughout the elevator to detect the SARS-COV-2, which helps protect passengers’ lives. This study uses fluent 2019R3 software to simulate the virus transmission to model the transient flows numerically. The analysis found that the ventilation system’s turbulent fields can be an effective method of protecting the space from being saturated by the coronavirus.

The influence of different shapes of nanoparticles on peristaltic flow of Casson fluid in an asymmetric channel is studied in this paper. The suspension of Copper oxide nanoparticles of needle, platelet and lamina shapes is taken into account. The problem is modeled in partial differential equations with suitable slip boundary conditions. The standard nonlinear equations are solved by the Homotopy Analysis Method in Mathematica Software. The influences of different shapes of nanoparticles on concentration, velocity profile and temperature profile are analyzed through the graphs. It is observed that the different shape of nanoparticles has different thermal conductivity, but the lamina shaped nanoparticles have high thermal conductivity as compared to needle and platelet shaped nanoparticles.

In this work, we investigated the geometrical structures, electronic and magnetic properties of S sites vacancy defects in heterostructure graphene/molybdenum disulphide ((HS)G/MoS${}_2)$ material by performing first-principles calculations based on spin polarized Density Functional Theory (DFT) method within van der Waals (vdW) corrections (DFT-D2) approach. All the structures are optimized and relaxed by BFGS method using computational tool Quantum ESPRESSO (QE) package. We found that both (HS)G/MoS₂ and S sites vacancy defects in (HS)G/MoS₂ (D1S–(HS)G/MoS₂, U1S–(HS)G/MoS₂, 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS${}_2)$ are stable materials, and atoms in defects structures are more compact than in pristine (HS)G/MoS₂ structure. From band structure calculations, we found that (HS)G/MoS₂, (D1S–(HS)G/MoS₂, U1S–(HS)G/MoS₂, 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS${}_2)$ materials have $n$-type Schottky contact. The Dirac cone is formed in conduction band of the materials mentioned above. The barrier height of Dirac cones from Fermi energy level of (HS)G/MoS₂, (D1S–(HS)G/MoS₂, U1S–(HS)G/MoS₂, 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS${}_2)$ materials have values 0.56eV, 0.62eV, 0.62eV, 0.64eV and 0.65eV, respectively, which means they have metallic properties. To study the magnetic properties of materials, we have carried out DoS and PDoS calculations. We found that (HS)G/MoS₂, D1S–(HS)G/MoS₂ and U1S–(HS)G/MoS₂ materials have non-magnetic properties, and 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS₂ materials have magnetic properties. Therefore, the non-magnetic (HS)G/MoS₂ changes to magnetic 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS₂ materials due to 2S and 3S atoms vacancy defects, respectively, in (HS)G/MoS₂ material. Magnetic moment obtained in 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS₂ materials due to the unequal distribution of up and down spin states of electrons in 2s and 2p orbitals of C atoms; 4p, 4d and 5s orbitals of Mo atoms; and 3s and 3p orbitals of S atoms in structures. Magnetic moment of 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS₂ materials is −0.11${\mu }_B$/cell and $-0.29{\mu }_B$/cell, respectively, and spins of 2p orbital of C atoms, 3p orbital of S atoms and 4d orbital of Mo atoms have dominant role to create magnetism in 2S–(HS)G/MoS₂ and 3S–(HS)G/MoS₂ materials.

The aim of this paper is to investigate the effect of hydrostatic initial stress and temperature dependence of the modulus of elasticity on surface wave propagation in the semiconducting medium under photothermal theory. An infinite elastic half-space is overlying the infinite semiconducting medium and a mechanical force of constant magnitude is applied along with the interface. Surface wave solutions are used to solve the coupled plasma, thermal, and elastic wave equations. The effect of hydrostatic initial stress and temperature dependent properties have been studied and depicted graphically on the penetration depths of the waves and the components of stresses, displacement, temperature distribution and carrier density. It is observed that the effect of hydrostatic initial stress on the penetration depths is prominent in temperature independent semiconducting medium.

This paper presents analytical solutions for bending and buckling of nonlocal functionally graded (FG) Euler–Bernoulli (EB) nanobeams. Material gradation along the thickness direction could be defined by a power function (P-FG), a sigmoidal function (S-FG), and an exponential function (E-FG). Laplace transform is applied to the differential form of the equation of motion of the nonlocal elasticity theory. Closed-form expressions for bending deflection and critical buckling load of FG nanobeams are derived. Effects of material gradations as well as the nonlocal parameter are examined. It is found that bending displacements and critical buckling loads could be controlled by an appropriate choice of material distribution parameter for P-FG nanobeams. The presented results also demonstrate the influences of factors such as the choice of material gradation, power-law index, and nonlocal parameter on bending and buckling behavior.

Formability of a material is found to be one of the important characteristic of a sheet metal to know the variation of the major and minor strain of a sheet metal, using this value one can predict the forming limit diagram of sheet metal, forming limit diagram gives the behavior of sheet metals under various loads and also helps in the prediction of breakage or necking of the material under specific load and velocity of the punch. Current study is mainly focused on obtaining the forming limit diagram of two different aluminium alloys like Al-5052 H32 and Al-6063 T5 using numerical analysis software PAMSTAMP and the results obtained are validated by conducting experiments, there is a good agreement of results between the experimental and numerical values. The forming limit diagram of the mentioned alloys helps in manufacturing of automobile and electric vehicle parts.