Dust storms in arid and semi-arid regions have harmful impacts on the environment, the economy, and the health of local and global communities. In this study, the frequency of annual dust events in twenty-five stations and five climatic variables including rainfall, maximum annual wind speed, average annual wind speed, maximum annual temperature, and average annual temperature in arid regions o...

all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...

A number of researches have indicated a gradual increase in mean temperature throughout the world. Yet, there are some reports on the reduction of annual mean temperature. In this research we investigated a long-term trend of annual mean temperature in 34 synoptic stations in Iran (2 stations in cold and humid climates 14 in humid and moderate climates, 11 in Steppe climate and 7 in desert clim...

A number of researches have indicated a gradual increase in mean temperature throughout the world. Yet, there are some reports on the reduction of annual mean temperature. In this research we investigated a long-term trend of annual mean temperature in 34 synoptic stations in Iran (2 stations in cold and humid climates 14 in humid and moderate climates, 11 in Steppe climate and 7 in desert clim...

The drying of Lake Urmia has had many environmental impacts on the surrounding areas of the lake. In this research, efforts have been made to identify vegetation coverings that are compatible with the study area and then it use of multiplicative decision-making models for identify areas susceptible to cultivation of these products. In the present study, following the study of species in the reg...

in this thesis,spin dependend transport and electron transport through of ng/sg(graphene/ superconductor graphen) are studied in the junction of ng/fgt/sg. due to andreev reflection conductance increases in the presence of superconductor graphene.also, by applying a voltage gate on a superconductor, fermi level shifts and the conductance is independent of ferromagnatic substrate. also, the cond...

This study investigated seasonal changes in density and diversity of phytoplankton, chlorophyll a content, and some environmental characteristics in the Sistan region during 2014. Totally, we detected 28 genera that belonged to five groups of Chlorophyta (12 genera), Bacilloriophyta (7 genera), Cyanophyta (5 genera), Dinophyta (3 genera), and Euglenophyta (1 genus). We observed that Chlorophyta...