The Gibbs conditions of stable thermodynamic equilibrium are formulated for nonlinear thermoelastic materials, based on the constrained minimization of four fundamental thermodynamic potentials. Sufficient conditions for incremental stability are stated in each case. The previously unexplored connections between the second-order variations of thermodynamic potentials are used to establish the c...

In this study, the thermal performance of three kinds of roofs with different heat capacity and thermal conductivity under different external conditions has been investigated using a numerical method. For this purpose, the combined solar radiation, conduction and convection heat transfer were calculated implicitly in terms of a one-dimensional finite difference method. Different high and low so...

in this paper the effect of site conditions, which are altitude, temperature and relative humidity and also heat dissipation capacity are investigated on the optimized design of natural draft dry cooling towers with specific kind of heat exchangers, known as forgo t60 type. a genetic algorithm program has been developed for optimized design of these cooling towers. objective function includes b...

This experiment was carried out to investigate the effects of different levels chromium picolinate (CrPic) and chromium nanoparticles (nano-Cr) on the performance and immune function of broilers under heat stress condition. A total of 320 Ross 308 broiler chicks (from 21 to 42 days) were assigned randomly into eight treatment groups (four replicates per treatment, and 10 chicks per replicate) a...

in order to determine the best index for evaluating maize genotypes, 15 maize inbred lines were evaluated in two planting dates, 6 july to coincide heat stress with pollination time and 27 july as normal planting to avoid high temperature during pollination and grain filling period, using a randomized complete block design with three replications, in shushtar city, in 2007. result showed that i...

the aim of this paper is to enhance thermal performance of a microchannel heat sink by using nanoencapsulated phase change material (nepcm) slurry as a cooling fluid instead of pure fluid. a threedimensional model of a circular channel using water slurry of nepcm was developed. the results show a significant reduction in the mean fluid temperature along the channel and heat sink wall temperatu...

in this paper, the conjugate gradient method coupled with adjoint problem is used in order to solve the inverse heat conduction problem and estimation of the time- dependent heat flux using the temperature distribution at a point in a three layer system with none homogeneous boundary conditions. also, the effect of noisy data on final solution is studied. for solving this problem the general co...

Steel pipes with circular cross-sections are usually used in cooling panels of electric arc furnaces. In the present study pipes with square cross-sections under equivalent conditions were used to obtain more information on the possibility of increasing the heat transfer and cooling efficiency. The results showed increased efficiency of the square pipe compared to the circular cross-section pip...