Environmental pollution and rapid depletion are among the chief concerns about fossil fuels such as oil, gas, and coal. Renewable energy sources do not suffer from such limitations and are considered the best choice to replace fossil fuels. The present study develops a mathematical model for optimal allocation of regional renewable energy to meet a country-wide demand and its other essential as...

Bus fleet data have consistently shown that vehicle operating and maintenance costs increase as vehicles age. A fleet manager has to deal with the tradeoff between the lower operating and maintenance costs of newer fleets and their higher initial capital costs as well as the tradeoff between conventional and fuel efficient bus technologies. This study formulates and implements a fleet replaceme...

Predicting the maintenance and management costs and replacement age of tractors in agricultural mechanized units, is important from several points. So, doing a timely agricultural operations, more accurate measure of the amount of income  including the cost of these items , determining the useful life of old tractors , replacement age, cost of the process changes and the possibility of examinin...

Exergy analysis is based on combined first and second laws of thermodynamics and is a useful tool to analyze the energy systems in a better and more realistic way than an energy analysis, based on the first law of thermodynamics. Combination of exergy from thermodynamics with conventional concepts from engineering economy which is referred to as thermo-economy (exergo-economy) is a valuable too...

Background: Laminar flow ventilation systems were developed to reduce surgical contamination in joint arthroplastyto avoid periprosthetic joint infection (PJI). The goals of this study are to evaluate the cost-effectiveness and economicviability of installing and maintaining a laminar flow system in an operating room.Methods: A Monte Carlo simulation was used to evaluate the c...

This paper presents a dynamic programming (DP) model of operating a nuclear power plant (NPP). In each period the operator decides whether to run the reactor, to shut it down for preventive maintenance or refueling, or permanently close the plant for decommissioning. The maximum life of a NPP is determined by the length of the operating license issued by the Nuclear Regulatory Commission. The o...

Preventive maintenance is the essential part of many maintenance plans. From the production point of view, the flexibility of the maintenance intervals enhances the manufacturing efficiency. On the contrary, the maintenance departments tend to know the timing of the long term maintenance plans as certain as possible. In a single-machine production environment, this paper proposes a simulation–o...

With regard to the importance of scientific decision-making in power plants prioritization to produce electrical energy (power) from renewable energies (purified), in this paper, research with specialists opinions with respond to questionnaires provided upon three efficient operational criterion in position of three presented power plant in country which used wind, solar water energies for prod...

Exergy analysis is based on combined first and second laws of thermodynamics and is a useful tool to analyze the energy systems in a better and more realistic way than an energy analysis, based on the first law of thermodynamics. Combination of exergy from thermodynamics with conventional concepts from engineering economy which is referred to as thermo-economy (exergo-economy) is a valuable too...