introduction: fasting, like islamic ramadan fasting, has been associated with health benefits. islamic ramadan fasting, a form of caloric restriction (cr) or alternate day fasting that. studies suggest a comparable effect of adf and caloric restriction. despite the fact that fasting can be considered as a form of dietary restriction, fasters tend to have difficulty to reduce their food intake d...

Multi-port microchannel tubes are increasingly popular for use in a variety of heat transfer applications, primarily for automotive condensers and radiators, but also in a variety of refrigeration and air conditioning applications. These channels offer a greater surface area to volume ratio, providing for enhanced heat transfer over a conventional tube in many applications. Previous research ha...

The primary goal of the work described in this paper was to evaluate and extend a virtual refrigerant charge sensor (VRC) for determining refrigerant charge for equipment having variable-speed compressors and fans. To evaluate the accuracy of the VRC, data were first collected from previous laboratory tests for different systems and over a wide range of operating conditions. In addition, new la...

A variety of hydrofluorocarbon (HFC) compounds, both as pure substances and mixtures, are being developed as alternative refrigerants to replace the exsting chlorofluorocarbons and hydrofluorocarbons which have been linked to stratospheric ozone depletion. The use ofHFC's in refrigeration systems will require new lubricants, and polyolesters are being widely promoted as the lubricant of choice ...

Data is presented for the vapor liquid equilibrium viscosity reduction of lubricants with two refrigerant blends at two temperatures. The lubricants tested were a 32 ISO VG mixed acid polyolester and a 32 ISO VG branched acid polyolester. The refrigerant blends used were HFC-125/143a/134a (44/52/4% w/w), and HFC-125/143a (50/50% w/w). INTRODUCTION This experiment detennined the vapor liquid equ...

A series of tests has been completed comparing the system performance of four long term replacements HP62 (44% R~125/ 54% R-143a/ 4% R-134a), AZ-50 (50% R-125/ 50% R-143a), Klea 60 (20% R-32/ 40% R-125/ 40% R-134a), and Klea 61 (1 0% R-32/ 70% R-125/ 20% R-134a) as potential alternatives for the CFC-containing low temperature refrigerant R-502. The tests were carried out under controlled condit...

Besides compressor rotary speed and parameters of water flowing through gas cooler and evaporator, refrigerant charge amount and electronic expansion valve (EEV) opening are two important parameters that have significant effects on the performance of a transcritical CO2 heat pump system. In this study, the effects of refrigerant charge amount on the performance of a transcritical CO2 heat pump ...