data envelopment analysis (dea) has been long employed as a popular methodology to evaluate the performance of various production activities with multiple inputs and outputs. however, an important issue is that the production process in the real world inevitably generates undesirable outputs (like wastes and pollutants) along with desirable outputs. therefore, the undesirable outputs should be ...

the relationship between some habitat factors and fish assemblage was analyzed in the taleghan river, alborz province, iran. fish specimens from thirty-three sites were sampled by electrofishing device in october 2014. the habitat parameters, including elevation (m), water depth (cm), river width (m), river slope (%), current velocity (m.s-1), number of large stone (> 15 cm), average stone diam...

swot analysis is used extensively as an assessment and planning method, particularly in tourism planning. however, there are little documentations on application of swot analysis in ecotourism. an assessment on systematic use of swot analysis was carried out in the present study to highlight the applicability of the swot technique in detailed investigations. in this study, based on field survey...

Solar energy has been one of the accessible and affordable renewable technologies for last few decades. Photovoltaics solar thermal collectors are mature to harness energy. However, efficiency photovoltaics decays at increased operating temperatures, suffer from low exergy. Furthermore, along with several financial, structural, technical socio-cultural barriers, limited shadow-free space on bui...

the aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (pahs) and polychlorinated biphenyls (pcbs) into two groups. this is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. in this process mixture of pahs and pcbs divide in two groups and simultaneously other...

the energy efficiency, greenhouse gas (ghg) emissions, and carbon efficiency of paddy rice production were analysed in sari in the mazandaran province of iran during 2011–2012. data was collected through questionnaires and interviews with paddy producers. the results showed that the net energy gain was 27,932 mj ha-1 and energy efficiency was 1.83 during production. the results of the cobb-doug...

aims: textile wastewaters are the most important health and environmental problems in kashan. this research was aimed to compare the poly aluminum chloride and chlorinated cuprous efficiency for removal of chemical oxygen demand (cod) and color from kashan textile industries company wastewater. materials & methods: this experimental bench scale study in a batch system was conducted on 20 compos...