the aim of this paper is eliminating cr(vi) by natural hap. hap is a inexpensive material which is used from bovine critical bone ash in order to remove heavy metal ions like cr(vi). some experiments in different ph are performed (ph=2,3,7). maximum adsorption was appeared at ph=2, dosage=0.3 gr, c0=10 mg/l. cr(vi) removal depends on ph value and initial amount of cr(vi) result of experiments w...

the purpose of the present study is to find out whether bilinguals of khuzestan-arab origin or monolinguals of iranian origin code-switch during learning or speaking english and which group is more susceptible to code-switch. to this end, the students of 24 classes from high schools and pre- university centers were screened out, and interviewed and their voices and code-switchings were recorded...

this study purported to compare and contrast the use of self-mention and evidentials as two mtadiscourse features in opinion columns of persian and english newspapers. the theoretical basis of this study is the idea that metadiscourse features vary across cultural boundaries. for this purpose, 150 persian and 150 english opinion columns were collected based on three factors of topic, audience a...

until now many studies have been done over recent decades throughout the world to show the right age to start english. in iran, research is still at an early stage in terms of evaluating teachers’ beliefs about teaching children english. the problem of at what age to start teaching english and how to teach english to elementary school children has not been solved neither in this country nor els...

the purpose of this study was to find the relationship between critical thinking and self-regulation with reading comprehension of iranian female elementary language learners. the present study is a correlational one having a descriptive design. two questionnaires, critical thinking questionnaire and self-regulation questionnaire which were valid and reliable questionnaires and four reading com...

one very decisive factor in students’ academic destiny is the result they get at final term examinations. because of its importance, both students and teachers are curiously anxious about them. as normally it is the case, these final term tests are prepared hurriedly in short time by teachers which result in students’ dissatisfaction, complaining on how the test was different from their expecta...

the purpose of this study was to investigate the impact of blended learning and multimedia softwares on iranian efl students vocabulary learning. in addition, the present study tried to examine the extent to which multimedia softwares can be applied into efl classes in iran. it also attempted to find out students attitudes toward using these softwares. to this end, 87 iranian efl learners at el...

many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...

چکیده اهمیت اشیاء در نگاه انسان از آغاز پیدایش در زندگی جریان داشته و تاکنون نیز ادامه دارد. ساخت اشیاء از انواع کاربردی و آئینی آغاز و تا انواع الکترونیکی آن به همزیستی مسالمت آمیزی با انسان منتهی گشته است. حال اینکه این همزیستی در هر دوره ای از تاریخ چگونه خودنمایی می کند از اهمیت بسیاری برخوردار است.این رساله به بررسی موقعیت شی از جنبه های زیبایی شناسی، هویت مداری، نمادگرایی، جامعه شناسی ...