the present study was an attempt to compare the effect of peer metalinguistic corrective feedback on elementary and intermediate efl learners speaking ability to see which level benefits more from this type of feedback. to this end, 117 female efl learners at grade 3, al-zahra high school in kermanshah, iran were non-randomly chosen. the homogeneity of the participants was attained through a pi...

due to the limiting workspace of parallel manipulator and regarding to finding the trajectory planning of singularity free at workspace is difficult, so finding a best solution that can develop a technique to determine the singularity-free zones in the workspace of parallel manipulators is highly important. in this thesis a simple and new technique are presented to determine the maximal singula...

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

abstract this study aimed at investigating the impact of etymology strategy instruction on the development of vocabulary of iranian intermediate efl learners. etymology, knowledge of origin of words, roots, and affixes, has proved to be a controversial issue and a question of long debate with regard to its impact on the process of vocabulary learning. this study employed etymology strategy in ...

in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...

in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...

in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...

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...

a major concern in the last few years has been the fact that the cultural centers are keeping distance with what they have been established for and instead of reproducing the hegemony, they have turned into a place for resistance and reproduction of resistance against hegemony. because the cultural centers, as urban public spaces in the last two decades, have been the subject of ideological dis...