Basic thermodynamics is able to treat an actual (non-equilibrium) process as well as the corresponding equilibrium process. An example of such a pair of processes is familiar to every chemical engineer; namely, (Joule) free expansion of a gas and the corresponding equilibrium exp...
Open access
Research Article10.9734/CSJI/2023/v32i6870
An attempt is made to explain the meaning of entropy in thermodynamics. A new concept of heat capacity is defined. For it, the temperature change is measured from 0 kelvin. It is supposed that the entropy of a substance is the sum of these heat capacities in the formation of the...
Open access
Research Article10.9734/PSIJ/2018/41666
When the pressure of a fluid changes without the addition of heat, the temperature of the fluid changes; the rate at which the temperature changes with pressure is called the adiabatic lapse rate. According to thermodynamic equations, the adiabatic lapse rate is positive if the t...
Open access
Research Article10.9734/PSIJ/2018/41720
It is shown that taking into account the negative compressibility of substances changes Maxwell relations. The earlier results of the author indicating that these relations differ for substances with negative thermal expansion have received additional confirmation. Universal Maxw...
Open access
Research Article10.9734/PSIJ/2017/33660
Previously, in the calculation of the internal energy of the ideal gas in statistical mechanics, it has been supposed that the volume is a constant, which does not depend on any arguments. However, the volume depends on pressure and temperature and its partial derivative is not e...
Open access
Research Article10.9734/PSIJ/2017/32822