Sharif Digital Repository

Solar heating and cooling technologies can have a vital role to play in understanding the targets in energy security, economic development, and mitigating climate change. This study aimed to investigate the performance of the combined solar cooling/heating system using a Photovoltaic Thermal collector (PVT) for residential applications. The main advantage of using PVT is the conversion of the maximum amount of solar energy into electricity and thermal energy. In this work, water is used to cool the panel and, consequently, increase the efficiency. The cooling cycle comprises a hybrid ejector-compression refrigeration cycle with two evaporator temperatures. To reduce the effect of the global... 

In this paper, implosion of a micron-sized air bubble was studied numerically using OpenFoam software package. Then a parametric investigation on the flow physics of the problem was performed. The results show that as the initial pressure of the liquid increases, the pressure and the temperature inside the bubble increases such that in some cases, the temperature is as high as the one required for luminescence. Also, increasing the density and the temperature of the liquid solely, decreases the intensity of the collapse. © 2018  

Prediction of threshold conditions and incipient motion is the essential issue for the study of sediment transport. This work compares existing empirical threshold curves proposed for Shields diagram, a method based on the concept of probability of sediment movement, and an empirical method based on movability number. These methods are used to predict the incipient motion conditions for experimental runs taken from various studies. Most of the experimental data, used in this work, have not been used before in derivation of alternative formulations for Shields diagram and other methods. The empirical threshold curves based on the Shields entrainment function was the least successful at... 

In this paper, we present a computational study on the electrical behaviour of self-switching transistors (SSTs) based on InGaAs/InP heterojunction. Our simulation is based on the solution of Poisson and Schrodinger equations self-consistently by using Finite Element Method (FEM). By using this method, electrical characteristics of device, such as (Formula presented.) ratio, subthreshold swing, and intrinsic gate-delay time are investigated. Also, the effects of geometrical variations on the electrical parameters of SSTs are simulated. We show that appropriate design of the device allows current modulation exceeding (Formula presented.) at room temperature. © 2021 Informa UK Limited, trading... 

In this paper, we present a computational study on the electrical behaviour of self-switching transistors (SSTs) based on InGaAs/InP heterojunction. Our simulation is based on the solution of Poisson and Schrodinger equations self-consistently by using Finite Element Method (FEM). By using this method, electrical characteristics of device, such as (Formula presented.) ratio, subthreshold swing, and intrinsic gate-delay time are investigated. Also, the effects of geometrical variations on the electrical parameters of SSTs are simulated. We show that appropriate design of the device allows current modulation exceeding (Formula presented.) at room temperature. © 2021 Informa UK Limited, trading...