in the sector of electricity production, the existence of investment resources limitation and environmental factors are the main factors that influence this process. the reduction of costs and the destructive impacts of environmental have been always mentioned by specialists. consequently, the drasticality of the environmental protection and the electric-energy production lead to focus on solar...

Several models have been proposed for scheduling the preventive maintenance (PM) of complex repairable systems in industry. These are often application-speci"c and some make unrealistic assumptions about stationarity of the process and quality of repairs. We investigate two principal types of general model, which have wider applicability. The "rst considers "xed PM intervals and is based on the...

The purpose of this research was studying relationship between socio- cultural, economical and managerial factors with the participation rate of agricultural cooperative's members in the Shirvan Chardavol township in the Ilam province, Iran. The method of this study is descriptive-correlative. A researcher made questionnaire was used as the tool for gathering data. The face and content validity...

Economists look at the entrepreneurship from the prospective of profitability, investment, risk, and insight supporting the economical development but it seems that, in modern societies, entrepreneurship`s function is beyond the economical bounds. According to the stage and importance of entrepreneurship which is known as the society’s economic and culture evolution engine, it is necessary to d...

science and technology have a vital role in the success and prosperity of human beings and is also called the most important instrument in the economical development. nowadays, no powerful country can get power without science and technology, in other words, no social and economical promotion will be attainable without these two keys. here in this research, in addition to analysis and the intro...

How the review was carried out is briefly described. The review looks mainly at the literature published since year 2000, but does not exclude earlier publications. The sustainability of practices to limit erosion must be assessed not only in terms of the soil resource and the wider environment but must also take into account economical and socio-political factors. Soil degradation may be due t...