This paper aims to determine the optimum price of electricity during restructuring process. We maximized social welfare function subject to market equilibrium, maximum production capacity of each group of power plants, maximum demand of each consumer type and the potential of electricity export and import. The model was run using 2007 monthly and annual data by means of GAMS optimization softwa...

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

Background and Aims: Heavy metals in atmospheric dust can enter the human body through ingestion, respiration and skin contact and cause various diseases. The aim of this study was to determine the concentration of lead, a heavy metal, in atmospheric dust and assess its health risk during the period between winter of 1397 and the fall of 1398 in regions 9, 10, 11 and 12 of Tehran Municipality, ...

Investigating of rainfall behavior in the spatial-temporal dimension and determining the tolerance thresholds of different geographical areas with respect to vegetation, animal life and human activities, is essential for any decision in the environment. Therefore, precipitation data of 27 stations were received from the Meteorological Organization during the 60-year period and After the data we...

    Background and Aim: Respiratory tract infections are one of the important causes of death among children in developing countries. Although their frequency is similar in both developed and developing countries, mortality due to them is 10-50 times higher in developing countries. Viruses are common causes of these infections among children and Influenza, adeno and respiratory syncytial virus ...

learning a second or foreign language requires the manipulation of four main skills, namely, listening, reading, speaking, and writing which lead to effective communication. it is obvious that vocabulary is an indispensible part of any communication, so without a vocabulary, no meaningful communication can take place and meaningful communication relies heavily on vocabulary. one fundamental fac...