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 study investigates the relationships between iranian efl teachers’ perfectionism, burnout and their teaching style preferences, and also the difference between male and female efl teachers and their teaching style preferences. to this end, a sample of 99 efl teachers (46 males and 53 females), who had years of teaching experience, were selected. the measurement scales used in this study we...

abstract this study investigates the teachers’ correction of students’ spoken errors of linguistic forms in efl classes, aiming at (a) examining the relationship between the learners’ proficiency level and the provision of corrective feedback types, (b) exploring the extent to which teachers’ use of different corrective feedback types is related to the immediate types of context in which err...

this study was conducted to investigate the effect of favorite-text on iranian intermediate efl learners’ vocabulary development. sixty learners from nour-al-mahdi english institute participated in the present study. having been homogenized by oxford placement test (opt), they were randomly assigned into two groups of 30, control and experimental. then both groups sat for a pre-test which was a...

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: advertisements are the most accessible type of authentic materials, and this is one reason why they are used more and more in english teaching classes. for this cause, studies in the field of advertisements are very widespread nowadays. for pun is one aspect which makes advertisements more interesting, it is used more than before in advertisements. use of puns makes an advertisement m...

the present study investigated the effect of the two vocabulary teaching techniques in est, namely the use of translation and the use of visual aids as two separate vocabulary teaching techniques. to answer the question of the study, a pretest (michigan test) was administered to the 58 randomly selected est students at khajeh nasiredin tusi university, faculty of mechanics. after the homogeneit...

abstract this study aimed at investigating the effect of bilingual teaching of cognate words (persian-english) on iranian upper intermediate efl learners’ knowledge of lexical development. for this purpose,100 subjects participated in this study out of which 40 learners were selected for this study and they were assigned into two groups, control and experimental. cross-language cognates (wor...

this research has been taken among the students of high school in karaj city during the years 1391 and 1392. this is a survey research and data gathering is through questionnaires. studying the “an analysis of students’ tendency toward non-native reference groups in karaj”. the questionnaire was distributed among 260 of these students who were chosen through multi step cluster sampling. conside...

in this thesis, phosphorus ylides [phbppy], [no2bppy] and [brbppy] have been synthesized through the formation of phosphonium salt and dihydrogenation, followed by the reaction of pd(oac)2 and the orthopalladated dinuclear complexes [pd(?-cl)(phbppy)]2, [pd(?-cl)(no2bppy)]2 and [pd(?-cl)(brbppy)]2 have been produced. the reaction of dinuclear complexes and bidentate ligands [l = bipy (2,2-bipyr...