evaluation of changes present in soil and water resources due to operation implement of floodwater spreading is necessary to assess their positive or negative resultant effect. rate of the internal sediment to diversion spreader channels, surface sedimentation and aggregation of the spreading field depth are most important effective attributes on the yield of floodwater spreading systems. these...

abstract: salicylic acid is a phytohormone with phenolic nature which has been proved its role in increasing plant resistance to biotic and abiotic stress in several studies. this study was performed in order to investigation of interaction between 0, 0.5 and 1.5 mm concentrations of salicylic acid, as a seed pretreatment and different levels of drought stress (100, 75, 50 and 25 percent of fie...

1. introduction isfahan oil refinery (isfahan, iran) is responsible for the production of huge amounts of oil waste. as the released organic compounds are highly toxic, carcinogenic, and mutagenic, they can potentially contaminate the soil and groundwater resources of the adjacent area. this is particularly important in isfahan where arid/semi-arid climate has limited the access to adequate sur...

in this research, moisture sorptions of sayer date were determined at 20, 30, 40 and 60°c, using the standard static gravimetric method developed by the european cooperation project cost 90. several mathematical models, namely gab, bet, iglesias & chirif and halsey were employed to fit the experimental data through non-linear regression. results indicate that equilibrium moisture content increa...

introduction earth has ever been exposed to environmental hazards. the hazards are continually occurring in the world in the recent years. among them, atmospheric elements have created many human and financial losses in different regions. one of the hazards is dust events and in its severe case is dust storm. it happens more frequently in arid and semiarid regions in deserts and their surroundi...

three hundred and fifteen day -old chickens were used to test the relationship between oxygen-derived free radicals and the biochemical, hematological and pathological alterations(associtd with ascites). they were randomly divided into three experimental groups and ascites were developed in two groups of animals by exposing them to low temperature or administration of triiodothyronine (t3,), an...

extended abstract   introduction the most important indicator of climate in a region is vegetation community. climate can be different over large areas, because of changes in vegetation community. vegetation influences weather and climate in its surrounding areas mostly by way of evapotranspiration and albedo so they play a role in the earth’s energy balance. these effects on the earth’s energy...

the behavior of suspended sediment during flood events is not only a function of energy conditions, i.e. sediment is stored at low flow and transported under high flow conditions, but also is related to the variations in sediment supply and sediment depletion. these changes in sediment availability result in so-called hysteresis effects. therefore, hysteresis pattern analysis is of great import...

introduction water vapor can spread in molecular, unstable and erratic phase and can also transfer by convection and advection process. this transfer happens from the earth and ocean surfaces to the atmosphere in hot air. this type of transfer is considered as the main pattern. in the studies of the atmosphere, one of the prominent factors to be considered is the complexity of water vapor and i...