We investigate the energetics of a Brownian motor driven by position-dependent temperature, commonly known as the Büttiker-Landauer motor. Overdamped models (M=0) predict that the motor can attain Carnot efficiency. However, the overdamped limit (M-->0) contradicts the previous prediction due to the kinetic energy contribution to the heat transfer. Using molecular dynamics simulation and numeri...

Fouling of heat exchangers is a severe problem in the industrialized world. The effects of fouling are reduced energy efficiency and increased greenhouse gas emissions. In fact, any heat transfer process has a risk of fouling on the heat transfer surface. The fouling can in some cases be cleaned physically, chemically or burned off; in other cases it may not be possible to clean the heat exchan...

Heat production serves as the standard measurement for the determination of energy expenditure and efficiency in animals. Estimations of metabolic heat production have traditionally focused on gas exchange (oxygen uptake and carbon dioxide production) although direct heat measurements may include an anaerobic component particularly when carbohydrate is oxidized. Stoichiometric interpretations o...

heat transfer mechanisms and the solidification process are simulated for a continuous casting machine and the geometric shape of the liquid pool is predicted considering different conditions. a heat transfer and solidification model is described for the continuous casting of steel slabs. the model has been established on the basis of the technical conditions of the slab caster in the continuou...

Energy saving is major matter in our global world, and heat exchanger is very useful for energy saving. Of course heat exchanger is most significant component for chemical reaction, distillation, dissolution, crystallization, fermentation etc. So the correct selection of heat exchanger is important in these processes. Spiral tube Heat Exchangers are known as excellent heat exchanger because of ...

Gene transfer systems for Gordonia polyisoprenivorans strains VH2 and Y2K based on electroporation and conjugation, respectively, were established. Several parameters were optimized, resulting in transformation efficiencies of >4 x 10(5) CFU/ micro g of plasmid DNA. In contrast to most previously described electroporation protocols, the highest efficiencies were obtained by applying a heat shoc...

Optimized GaN-based light-emitting diodes (LEDs) were recently demonstrated to emit photons of higher energy than provided by the injected electrons up to elevated currents beyond the peak of the power conversion efficiency. Correspondingly, the electrical efficiency is above unity, which is attributed to heat extraction from the crystal lattice. In good agreement with measurements, we investig...

Boiling is a common mechanism for liquid-vapor phase transition and is widely exploited in power generation and refrigeration devices and systems. The efficacy of boiling heat transfer is characterized by two parameters: (a) heat transfer coefficient (HTC) or the thermal conductance; (b) the critical heat flux (CHF) limit that demarcates the transition from high HTC to very low HTC. While incre...

Experimental investigations has been done to find out the heat transfer characteristics and friction factor of water based Al2O3 nanofluids as a coolant in  brazed plate heat exchanger. Plate heat exchanger either use horizontally or vertically. The base plate of the plate heat exchanger was kept inclined at (0⁰, 30⁰ ,60⁰, 90⁰). The experimentation have been done on the two different concentrat...