Some years ago Vignati (refs. 1, 2, 3) showed that, under some particular circumstances (inter alia : isobaric processes connected through internal heat exchangers), the efficiency of an Ericsson cycle involving a real gas can exceed the Carnot limit ηC , in contradiction with the second principle of thermodynamics. However, the convergence of Vignati’s algorithm, giving the temperature differe...

Heatwave intensity and frequency are predicted to increase in the coming years, and this will bear adverse consequences to the environmental well-being and the socioeconomic fabric in urbanized areas. The hazardous combination of increased heat storage and reduced water retention capacities of the land surface make the urban areas warmer than the surrounding rural areas in what is commonly know...

The heat transfer model of vertical ground heat exchangers for ground-source heat pump systems is discussed. An explicit solution of a finite line-source model has been derived to better describe temperature response of boreholes for long time steps, which can be easily incorporated into computer programs for thermal analysis of ground heat exchangers. A quasi-three-dimensional model is also pr...

A-Type heat exchangers are used to meet required heat load with minimum duct dimensions in air-conditioning applications. This greatly reduces the air-conditioning system footprint in residential and commercial applications. The angle and tube spacing of the A-type heat exchangers should be optimized for minimum duct size and maximum heat load. However, existing air side heat transfer and press...

The objective of this paper is to develop and test a model of cost estimating for the shell and tube heat exchangers in the early design phase via the application of artificial neural networks (ANN). An ANN model can help the designers to make decisions at the early phases of the design process. With an ANN model, it is possible to obtain a fairly accurate prediction, even when enough and adequ...

Abstract Heat-moisture treatment is a physical method for starch modification to improve its functional properties depending on the application. The functional characteristics of the heat-moisture treated starch depend upon the source of starch and treatment conditions including time and temperature. The main objective of this study was to determine the functional properties of heat-moisture tr...

use of wastewater treatment methods in aquaculture is one of the main ways for decreasing the environmental effects of this industry and applies the best management practices (bmps). anionic compounds are the main pollutants in recirculation aquaculture systems. ion exchangers such as clays are vastly applied in waste water industry but in aquaculture systems at yet there isn't any report ...

Due to the wide range of design possibilities, simple manufactured, low maintenance and low cost, cross-flow heat exchangers are extensively used in the petroleum, petrochemical, air conditioning, food storage, and others industries. In this paper a mathematical model for cross-flow heat exchangers with complex flow arrangements for determining ε-NTU relations is presented. The model is based o...

Gray whales (Eschrichtius robutus) expose their immense oral cavities repeatedly to frigid waters when feeding. Morphological structures for heat conservation in the tongues of gray whales are described here in detail. Numerous individual countercurrent heat exchangers converge at the base of the tongue to form a bilateral pair of vascular bundles called the lingual rete. Temperature measuremen...