in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

the rationale behind the present study is that particular learning strategies produce more effective results when applied together. the present study tried to investigate the efficiency of the semantic-context strategy alone with a technique called, keyword method. to clarify the point, the current study seeked to find answer to the following question: are the keyword and semantic-context metho...

the following question poped up: is there any relationship between iranian high school efl learners reading comprehension and listening comprehension? then the following null hypothesis (ho) was developed to the test the above, mentioned question. "there is no relationship between high school efl learners reading comprehension and listening comprehension. for nearly 16 weeks, the experimental g...

abstract previous researches have shown success of growth hormones usage on flower production increase, pod and prevention of abscission of them in some of the pulses. two tests were done, in order to find out the effects of growth hormones to on flower production increase, pod and chick pea yield composites in farmer conditions (2010-11) and green house conditions as factorial on the proje...

today the image of a permanent skeletal space of cities affected by some forces or mechanisms is put in time with social-economic development and while imposes a new face and perspective to physical anatomy of cities, and prepares field to changes in content and social- economic structures of cities too. simultaneously with quitting villages in order to settle in cities by villagers, the phen...

در این پژوهش بس لایه های co-cu/cu و fe-co-cu/cu بر روی زیر لایه شیشه /طلا به روش الکتروانباشت لایه نشانی گردید. ناهمواری های سطحی این لایه ها به وسیله میکروسکوپ نیروی اتمی بررسی شده و سپس با رسم نمودار ناهمواری سطحی بر حسب طول اسکن در مقیاس لگاریتمی نوع و اندازه ناهمواری های سطحی مورد محاسبه قرار گرفت. ساختار بس لایه ها توسط پراش اشعه ایکس مورد مطالعه قرار گرفت و پیک های مشخصه و ساختار بلوری لا...

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...