in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

  Application of meteorological indicators has extensive use in drought monitoring. However, hydrological indicators can also play an effective role in this task. In this research, one of the rare approaches in drought monitoring with hydrological indicators namely Chang method has been applied and assessed for the Tehran basin using daily time step. The results have been compared with the uniq...

Drought is a phenomenon that threating water quality in addition to its shortage. In this paper we investigate the effect of drought on surface water quality of Kashkan watershed. For this purpose, during the collection of meteorological data and water quality data during 20 years (1987 to 2009) from Meteorology and Water Resources offices of Lorestan province, initially duration and severity o...

Drought is an extended period of low precipitation which resulted in injuries to consumers of water and reducing their performance, especially in agriculture. Different indices have already been proposed for evaluating drought, based on one of the varieties of meteorological, hydrological and agricultural droughts, but no indices has been identified yet, encompassing all factors. This study has...

Groundwater is one of the most important resources of water in the world. Studies show that low rainfall, persistent droughts, and over-exploitation have caused economic and environmental damage. Therefore, this study was conducted to evaluate the effects of rainfall and drought on the groundwater of Kashmar plain as one of the most important fertile plains of Khorasan Razavi in eastern Iran,...