The negative nature of the heat capacity CV of thermodynamically isolated self-gravitating systems is rediscussed in the framework of a non-extensive kinetic theory. It is found that the dependence of CV on the non-extensive parameter q gives rise to a negative branch with the critical value corresponding to q = 5/3 (CV → −∞).

Polytetrafluoroethylene can be considered as a model for calorimetric studies of complex systems with thermodynamics transitions at ambient temperature. This polymer exhibits two phase transitions of different nature at 292 K and 303 K. We show that sensitive accalorimetry measurements allow us to study the thermodynamic behaviour of polytetrafluoroethylene when it is brought out of thermodynam...

the kinetics and mechanism of the reaction of 5-nitro-1h-benzo[d] imidazole to produce 6-nitro-1h-benzo[d] imidazole was studied by employing hybrid meta-density functional theory. mpwblk/6-31+g** level calculations were carried out to obtain energies and optimize the geometries of all stationary points along the pes, and determine the harmonic vibrational frequencies. two transition states (ts...

Chip-scale optical microresonators with integrated planar optical waveguides are useful building blocks for linear, nonlinear, and quantum-optical photonic devices alike. Loss reduction through improving fabrication processes results in several integrated microresonator platforms attaining quality (Q) factors of several millions. Beyond the improvement of the quality factor, the ability to oper...

The object of the present paper is to study temperature distribution and thermal stresses of a functionally graded thick hollow cylinder with temperature dependent material properties. All the material properties except Poisson’s ratio are assumed to be dependent on temperature. The nonlinear heat conduction with temperature dependent thermal conductivity and specific heat capacity is reduced t...

pistachio has a special ranking among iranian agricultural products. iran is known as the largest producer and exporter of pistachio in the world. agricultural products are imposed under different thermal treatments during storage and processing. designing all these processes requires thermal parameters of the products such as specific heat capacity. regarding the importance of pistachio proces...

in this paper, a new systematic design methodology has been developed for thes imultaneous energy and water minimization in multiple-contaminant systems that also feature maximum re-use of water. in addition to allowing re-use of water in multiple-contaminant systems, issues about heat losses and flowrate changes inside unit operations have also been incorporated in this new design method. to i...