a simple semi-phenomenological model, which accurately predicts the dependence of thresholdcurrent for temperature of resonant-phonon three well quantum cascade laser based on verticaltransitions is offered. we found that, the longitude optical phonon scattering of thermally excitedelectrons is the most important limiting factor for thermal performance of high frequency thz qcls.in low frequenc...

fluids for various industrial applications because of their excellent thermal performance. this study analytically and experimentally examines the effects of nanoparticle dispersion on the entropy generation of eg–al2o3 nanofluid flows through a helical pipe as a heat exchanger under constant wall heat flux thermal boundary condition in laminar regime. it is found that adding nanoparticles impr...

Window frame material has significant impact on the thermal performance of the window. Moreover, with sustainable design becoming a necessity, window frame materials need to have higher levels of environmental performance to be considered sustainable. As a result, a holistic performance metric is needed to assess window frame material. Three similar frames were considered, manufactured from alu...

The loss of energy especially in industrial and residential buildings is one of the main reasons of increased energy consumption. Improving the thermal insulation properties of materials is a fundamental method for reducing the energy losses. Polymeric foams are introduced as materials with excellent thermal insulation properties for this purpose. In the present study, a deep theoretical invest...

a small salt gradient solar pond with an average surface area of 1.8 m2 and depth of 0.8m has been tested. the depths of storage, gradient and surface zones are 0.3, 0.27 and 0.07m, respectively. the temperature of the storage zone for the summer days reaches its maximum of 65˚ c after about 8 days. daily variation of the storage zone temperature was about 8˚c which is due to small volume of th...

in this study, effect early age feed restriction and thermal conditioning on growth ,carcass characteristics broiler chickens subjected to heat stress was evaluated. three hundred chicks (cobb500) were randomly divided into four equal groups as treatments including thermal conditioning group (tc), feed restriction-thermal conditioning group (tcfr), feed restriction group (fr) and control group ...