In this paper, a hybrid solid oxide fuel cell (SOFC) and micro gas turbine (MGT) power system is parametrically studied to evaluate the effect of different operating conditions. The SOFC/MGT power system includes SOFC reactor, combustion chamber, compressor and turbine units, and two heat exchangers. The effects of fuel utilization, temperature, and pressure are assessed on performance of t...

As a necessary component, regenerator plays an important role in the refrigeration performance of the pulse tube refrigerator. The objective of this research is to investigate the flow characteristics in a porous regenerator of the pulse tube refrigerators, subjected to oscillating flow. The hydrodynamic and thermal behavior of the regenerator is investigated by considering porous media approac...

Availability analysis is based on the combination of First and Second Laws of Thermodynamics. Availability is defined as the maximum amount of potential work in relation to the surrounding environment. In the present paper, availability loss method was applied to evaluate a dual-evaporator vehicle air conditioning (A/C) system in order to identify a critical component that had led to the poor s...

The exergy analysis is a proper method for performance evaluation of industrial systems. A generic and detailed analysis of the GPCSs on the second gas pipeline of Iran  is made by the means of exergy. The two main improvement measures of fuel pre-heating and steam injection technologies are presented for the current conventional stations. Steady state equations regarding the second law of ther...

There are three so-called laws that underlie the science of toxicology. Paracelsus is usually considered to be the father of toxicology, having formulated the first law, which states that the dose makes the poison. The second law concerns the specificity of toxic effects of individual chemicals, a specificity due to the unique chemical structure of the agent and the laws of biology that govern ...

We have investigated the population distribution of Chinese cities from 1997 to 2006. The rank-size distributions of Chinese cities deviate from the Pareto distribution. For city size distribution of each year we can find a population threshold Pc that characterizes the boundary of the deviation. The cities with population more than Pc follow the Pareto distribution, while the smaller cities de...

The historical development of thermodynamics follows the industrial revolution in the 19 century, and the advent of heat engines. It is interesting to see how such practical considerations as the efficiency of engines can lead to abstract ideas like entropy. An idealized heat engine works by taking in a certain amount of heat QH , from a heat source (for example a coal fire), converting a porti...