This paper describes the modeling of the resonant-tunneling hot-electron transistor (RHET). In the analysis of the resonanttunneling harrier, we solved the Schrodinger and the Poisson equations self-consistently. We simulated the electron transport in the base and the collector barrier region using the Monte Carlo method, taking account of the space charge in the collector barrier. Our model in...

This experimental study is intended to explore the heat performance of a novel vacuum tube heat collector with thermal storage. In order to enhance the heat transfer performance, we add radial metal fins to the U-tube which is used as the heat transfer channel of water. Meanwhile, in order to increase the thermal capacity of the heat collector, the heat collector model is designed to be larger ...

an experimental and theoretical energy and exergy analysis was conducted for a cylindrical cavity receiver employed in a parabolic dish collector. based on simultaneous energy and exergy analysis, the receiver average wall temperature and overall heat transfer coefficient were determined. a simplified nusselt number for heat transfer fluid (htf) through the receiver as a function of reynolds an...

This paper deals with the performance of a heat pipe solar collector. The solar collector consisted of an interconnected heat pipe so as to reduce the production cost by using an interconnected heat pipe because all the heat pipes can be evacuated, sealed and tested at once. Performance of a prototype of the heat pipe solar collector was experimentally examined, and the results were compared wi...

In this work, adsorption of the potassium amyl xanthate collector on the pure chalcopyrite surface was studied by applying atomic force microscopy (AFM). The adsorption experiments were carried out at different concentrations of the collector and at diverse pH values in the presence or absence of exterior ions. The changes occurring in the surface morphology of chalcopyrite due to the collector...

Solar chimney power plants are plants based on solar thermal power including three parts of collector, chimney and turbine, which is able to produce electrical energy. One of the effective parameters in increasing the power production is the collector angles versus horizon. In the present study, a numerical analysis of a solar chimney power plant for different angles of the collector (divergent...

A separation technique which has recently received a sharp increase in research activities is "ion flotation". This technique has four important advantages for treating wastewaters: low energy consumption, small space requirements, small volume of sludge and acting selectively. The present study aims to optimize parameters of ion flotation for cadmium removal in simulated wastewater at laborato...

Exploitation of solar energy for achieving low temperature is an active area of research at present owing to the concern over suitable alternatives to synthetic refrigerants and large electricity consumption by conventional vapour compression systems. Present work theoretically design and analyze the performance of a solar flat-plate collector-driven water-Lithium bromide absorption refrigerati...

Flat plate solar collector (FPSC) is commonly used due to its low price, less complexity, and easier installation operation. The thermal efficiency the main disadvantage of this type collectors. In present study, performance FPSC using alumina oxide -water copper nanofluids are evaluated. effect nanoparticle volume fraction investigated theoretically validated experimentally. A computational fl...

A problematic issue with the solar water heaters is storage tank requirement, which takes considerable space and makes piping installation more difficult. This study first report on experimentally applying a shape-stabilized PCM to tankless direct-absorption evacuated tube collector address this challenge directly store energy. The proposed salt hydrate was synthesized at various concentrations...