Islamic Azad University

About: Islamic Azad University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Adsorption. The organization has 83635 authors who have published 113437 publications receiving 1275049 citations. The organization is also known as: Azad University.

A comparative study on the B12N12, Al12N12, B12P12 and Al12P12 fullerene-like cages.

Abstract: The stability, geometry and electronic structure of the title nanoclusters were compared by using density functional theory (DFT) calculations. Their electrical property analysis showed that the relative magnitude of the HOMO-LUMO gaps (eV) that are average values from the calculated results with five different DFT functionals is as follows: $$ {{\text{B}}_{{{12}}}}{{\text{N}}_{{{12}}}}\left( {{7}.0{2}} \right){ } > > {\text{ A}}{{\text{l}}_{{{12}}}}{{\text{N}}_{{{12}}}}\left( {{4}.0{9}} \right){ } > { }{{\text{B}}_{{{12}}}}{{\text{P}}_{{{12}}}}\left( {{3}.{8}0} \right){ } > {\text{ A}}{{\text{l}}_{{{12}}}}{{\text{P}}_{{{12}}}}\left( {{3}.{39}} \right). $$ Computing the standard enthalpy and the Gibbs free energy of formation, it was found that the B12N12 structure is thermodynamically stable at 298 K and 1 atmosphere of pressure, while the Al12N12 structure may be stable at low temperatures. Due to positive values of change of enthalpy and entropy of formation for both the B12P12 and Al12P12 clusters, it seems that their formation from the consisting atoms is not spontaneous at any temperature.

Mixed Convective Heat Transfer for MHD Viscoelastic Fluid Flow over a Porous Wedge with Thermal Radiation

Abstract: The main concern of the present paper is to study the MHD mixed convective heat transfer for an incompressible, laminar, and electrically conducting viscoelastic fluid flow past a permeable wedge w...

Numerical optimization of microchannel heat sink (MCHS) performance cooled by KKL based nanofluids in saturated porous medium

Abstract: This work presents a thermal and flow analysis of a fin shaped microchannel heat sink (MCHS) cooled by different nanofluids (Cu and Al2O3 in water) based on “saturated porous medium” and least square method then results are compared with numerical procedure. The Forchheimer–Brinkman-extended Darcy equation is used to describe the fluid flow and the two-equation model with thermal dispersion is utilized for heat transfer. The effect of nanoparticle size and volume fraction, volume flow rate, inertial force parameter and channel width investigated on total thermal resistance, friction factor and Nusselt number. The effective thermal conductivity and viscosity of nanofluid are calculated by KKL correlation. Central composite design (CCD) is applied to obtain the desirability of the optimum value of the nanofluid flow characteristics. Results show that Cu–water nanofluid is more lucrative thermally versus Al2O3–water nanofluid. It is found that total thermal resistance, friction factor and Nusselt number are not sensitive to inertial effect while they change significantly due to other parameters such as nanoparticle size and volume fraction, volume flow rate and channel width. We obtained that Nusselt number enhancement has direct relationship with inertial force parameter and volume flow rate.