soil erosion by water is the main factor of land degradation, particularly in semi-arid regions where soil productivity is usually low and lowering soil quality can severely decrease crops yields. this study was done in an area of 900 km2 in the semi-arid agricultural region of hashtroud in northwestern iran to determine the relationship between soil productivity and soil erodibility. wheat gra...

according to the importance of careful review of crude oil market fluctuations on the iranian economy, in this paper a multivariate model of markov switching vector error correction model (have been used). variables such as real gross domestic product in industrial sector, real effective exchange rate, real governmental expenditure, real import, inflation rate and real crude oil price is used t...

This paper expands a model different from existing models to analyze the cost and benefit of areinforced concrete solar chimney power plant (RCSCPP) built in the desert regions of Iran.Based on the model and some assumptions for values of parameters, this paper calculates totalnet present value (TNPV) and the minimum electricity price in each phase by dividing the wholeservice period into four ...

Abstract             In this research, an integrated inventory model for non-instantaneous deteriorating items is analyzed when demand is sensitive to changes in price. The price used in this research is a time-dependent function of the initial selling price and the discount rate. To control the deterioration rate of items at the storage...

The fate of private lands is widely seen as key to the fate of biodiversity in much of the world. Organizations that work to protect biodiversity on private lands often hope that conservation actions on one piece of land will leverage the actions of surrounding landowners. Few researchers have, however, examined whether protected lands do in fact encourage land conservation nearby or how protec...

in this paper, we investigate variations of gold coin price and also probe to model the fluctuations and conditional variance of coin market returns. the data consist of daily market prices of gold coin over the 1380 – 1386 period. since volatility clustering is viewed in time series of returns, we employ arch (autoregressive conditional heteroskedasticity) methodology in order to model the var...

raisin is the second major export item in iranian agricultural section after pistachio. in this study, effects of exchange rate fluctuations were investigated on quantity and price of exported raisin. therefore, data of 1970 to 2008 were reviewed by time series analysis and estimated by auto-regressive distributed lag model (ardl). results show the absence of a long-term relationship between ex...