fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

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abstract chickpea is weak in competition of weeds that damages to it at between 40 t0 60 percent. kermanshah province is one of the most important region for chickpea fields in iran. for these reosons, weed management is necessary in this crop. in order to evaluate of herbicides and stubble control on broad leave weeds control in chickpea. experiment was conducted in agricultural research stat...

during the process of reading, sometimes learners use ineffective and inefficient strategies and some factors may influence their use of strategies. perhaps critical thinking is one of these factors. this study aims to identify those categories of reading strategies that are mostly used by iranian efl learners and to see if there is any significant relationship between the critical thinking abi...

1.0 overview it seems that grammar plays a crucial role in the area of second and foreign language learning and widely has been acknowledged in grammar research. in other words, teaching grammar is an issue which has attracted much attention to itself, and a lot of teachers argue about the existence of grammar in language teaching and learning. this issue will remind us a famous sentence f...

the ability to speak two languages in the world is a remarkable achievement. there is a good reason to believe that bilingualism is the norm for the majority of people in the world because 70% of the earth’s population are supposed to be bilingual or multilingual. various investigations have shown that the native language impacts foreign word recognition, and this influence is adapted by the de...

چکیده اساسی ترین منبع استراتژیک هر سازمان یا جامعه،منابع انسانی می باشد.جوامع موفق،جوامعی هستند که بتوانند منابع انسانی خود را به طور صحیح پرورش و توسعه دهند. در اقتصاد امروز، دانش به عنوان مهمترین سرمایه، جایگزین سرمایه مالی و فیزیکی شده است . دانش و اطلاعات به رشد اقتصادی کمک می کند.این امر موجب افزایش اهمیّت سرمایه فکری به عنوان مقوله ای پژوهشی شده است. مدیریت منابع انسانی یعنی مدیریت و ادار...

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...