this study represents effect of four variables in performance of a heat-pump in two cities of tehran and rasht. a computer program has been developed, simulating a certain heat pump acting in different environments with different refrigerants in heating season. the analysis is based on a homogeneous model. effect of different refrigerants, depth of the buried heat exchangers and moisture conten...

a new method of optimization on linear parabolic solar collectors using exergy analysis is presented. a comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. by applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

The Gibbs free energy of mixing dissipated when fresh river water flows into the sea can be harnessed for sustainable power generation. Pressure retarded osmosis (PRO) is one of the methods proposed to generate power from natural salinity gradients. In this study, we carry out a thermodynamic and energy efficiency analysis of PRO work extraction. First, we present a reversible thermodynamic mod...

The thermal efficiency of a distillation column may be improved by permitting heat exchange on every tray rather than only in the reboiler and the condenser. Thermodynamic length optimizations on discrete systems specify the optimal temperature of each tray and consequently the amount of heat to be added or withdrawn in order to maintain that temperature.

This paper synthesizes a recent line of work on automated predictive model making inspired by Rate-Distortion theory, in particular by the Information Bottleneck method. Predictive inference is interpreted as a strategy for efficient communication. The relationship to thermodynamic efficiency is discussed. The overall aim of this paper is to explain how this information theoretic approach provi...

The goal of this paper is to perform a general thermodynamic study of Marangoni-driven engines in which chemical energy is directly transformed into mechanical motion. Given that this topic has not been discussed before, we will explore here the most basic and fundamental aspects of the phenomena at work, which leads to a number of interesting observations typical of controversies in classical ...

Quantum dot (QD) solar cells have the potential to increase the maximum attainable thermodynamic conversion efficiency of solar photon conversion up to about 66% by utilizing hot photogenerated carriers to produce higher photovoltages or higher photocurrents. Three quantum dot solar cell configurations are described.

Long-term contrasts in agricultural management can shift soil resource availability with potential consequences to microbial carbon (C) use efficiency (CUE) and the fate of C in soils. Isothermal calorimetry was combined with 13C-labeled glucose stable isotope probing (SIP) of 16S rRNA genes to test the hypothesis that organically managed soils would support microbial communities with greater t...

This report describes three 2400-MW(t) reference point designs for the moltencoolant gas cycle (MCGC), based on the current power conversion unit (PCU) designs for the GT-MHR. A very-high-temperature helium cycle with a 900°C turbine inlet temperature achieves a thermodynamic efficiency of 54% and net electric output of 1300 MW(e), while a low-temperature helium cycle with a 600°C turbine inlet...