Construction of a dam in the upstream of Tajan basin, as one of the human activities in order to provide drinking water, hydropower, agriculture, flood control or other purposes, can be effective on other sectors such as water resources. The purpose of this study is investigating the impact of Rajaei dam on groundwater resources in Sari-Neka plain during 26 years period (1985-2011) using geosta...

The lack of water resources in Iran has increased concern about water consumption in the country. The agricultural sector is known as the largest sector of water consumption, and saving in this sector will save significant water resources. One of the solutions for the optimal use of water resources is the use of modern irrigation methods with proper design and implementation. Therefore, the pur...

Increasing population and consequently demand for water needs, food supplies are among the limitations that the current world faces. The existence of such a process with limited natural resources needs to improve the optimal and continuous exploitation of available resources. Watershed management is one of the suitable ways to meet nutritional needs and prevent economic consequences. It is impo...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

Predicting the amount of water consumed would help the managers in exploitation of underground water systems so that they could manage consumption effectively. This issue, especially in Iran with repeatedly drought and limited water sources is significantly more important. In the present research, by using, artificial neural networks as a powerful tool in non-linear and indefinite processes hav...

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...