flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

this ethnographic case study research was carried out in a private school setting in the context of iran. the research tried to explore the analysis and identity construction of a group of learners and teachers along with the content analysis of books on the basis of four types of commodified, political, national and narrative identities. how english language learners and teachers in an informa...

the present study was conducted to investigate the role of summary in teaching grammar process on pre-university students. to this end, 48 male pre-university students in semnan were participants. they were math class that we called experimental group and science class as control group. in order to make sure there was no significant difference in proficiency level of two groups. a pre-test wa...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...

abstract this study evaluated and compared medical terminology and english for the students of medicine (ii) as two representatives of the textbooks available on the iranian market for teaching english to the students of medicine. this research was performed on the basis of a teacher’s and a number of students’ attitudes and the students’ needs analysis for two reasons: first, to investigate...

esl/efl books play a crucial role in shaping language learners worldview of gender roles in society. the present study investigated the status of sexism in two sets of efl textbooks, one developed by non-native iranian authors (ili series) and the other by native authors (top notch series). first, two books from each series was selected randomly. then, a quantitative analysis was carried out wi...

introduction acetic acid bacteria are large group of obligate aerobic gram negative bacteria with the ability to oxidize ethanol to acetic acid (1). they are widely distributed in natural habitats and classified in family acetobacteraceae. members of this family are useful in industrial production of vinegar(2). acetic acid bacteria (aab) can use substrates as glucose, ethanol, lactate or glyc...

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...

the effect of learning strategies on the speaking ability of iranian students in the context of language institutes abstract language learning strategies are of the most important factors that help language learners to learn a foreign language and how they can deal with the four language skills specifically speaking skill effectively. acknowledging the great impact of learning strategies...

determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...