abstract the current study set out to address the issue as to whether the implementation of portfolio assessment would give rise to iranian pre-intermediate efl learner autonomy. participants comprised 60 female in pre-intermediate level within the age range of 16-28.they were selected from among 90 language learners based on their scores on language proficiency test -key english test. then, t...

With industrial and economic growth and production of different compounds and chemical materials which human being has gained using natural resources for his ease and comfort , in turn , he introduces matters such as heavy metals and toxic agents into the nature , an unwanted process which leads to serious problems and dangers either for environment or for himself. This study aims at determina...

Background and purpose: PAHs are the most important pollutants of groundwater resources. Therefore, this study aimed at determining the PAHs concentrations in water samples exploited from wells near gas stations in Hamadan, Iran. Materials and methods: We collected 52 water samples from 30 cm depth of the wells from 13 gas stations in winter and spring in 2012. The extraction and identificatio...

Background and Objective: Water corrosion leads to increase in toxic metals concentration, such as arsenic, copper, lead, cadmium, zinc, nickel, iron and manganese in water. Toxic metals in water consumers cause acute health risks. Scaling water leads to economic and technical problems. Thus, The aim of this study was to investigate the corrosion and scaling potential of wells drinking wate...

this study attempts to investigate the effect of peers’ revision in comparison to that of the teacher, and whether peers’ comments and teachers’ comments facilitate students’ revision? if yes, which one is more effective? also attempts have been made to see which aspects of language are more highlighted by peers versus teachers when commenting. besides, it is investigating the student’s attitud...

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...