Dates of start and end of frost based on minimum shelter temperature equal to or less than 0°C were studied in Zanjan, Ghazvin and Tehran during 1961-2000. The cause of these frosts was determined by weather parameter values at observation hours and the aid of synoptic maps. Frost series based upon last spring or first fall advection are defined and found to be random and normally distributed. ...

Dates of start and end of frost based on minimum shelter temperature equal to or less than 0°C were studied in Zanjan, Ghazvin and Tehran during 1961-2000. The cause of these frosts was determined by weather parameter values at observation hours and the aid of synoptic maps. Frost series based upon last spring or first fall advection are defined and found to be random and normally distributed. ...

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...

One of the important points for successful production in soilless culture system is the right fertilization timing during plant growing period for each substrate. In this respect, a factorial experiment based on completely randomized design with five replications was conducted at Sari University of Agricultural Sciences and Natural Resources. Treatments were four chemical fertilization timings ...

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...