the main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. a simple way to take a sample of size n is to let all the possible samples have the same probability of being selected. this is called simple random sampling and then all units have the same probability of being ch...

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...

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...

methodology non-native participants in this study were sixty ba students majoring in english literature and teaching english as a foreign language at khayyam university of mashhad. they were senior students, between 21 to 24 years old, who had studied english for at least three and a half years and had passed several courses including grammar, reading, conversation, and writing. this was assum...

abstract the primary purpose of this study was to explore the actual practices and cognitions of two groups of iranian eap teachers, i.e. language teachers and content teachers, with respect to teaching reading-comprehension and vocabulary. to this end, tehran university of medical sciences which authorizes both groups of teachers to teach eap courses was selected as the context of the study s...

جان برتن استاد بازنشسته دانشگاه سنت‏اندروز، مولف کتاب جمع‏آوری قرآن است. این اثر در سال 1977 توسط انتشارات دانشگاه کمبریج به چاپ رسید. در نگاه اول، اثر مذکور مشتمل بر دو بخش و هر بخش دارای پنج فصل است. مولف در بخش اول به مسأله نسخ می‏پردازد و در مورد این که آیا قرآن سنت را نسخ کرده و یا بالعکس، به تفصیل سخن می‏گوید. نظرات شافعی و مخالفانش را در این‏باره به طور مشروح بیان می‏کند. وی سه شکل ن...

the issue of curriculum and syllabus evaluation and revision has been in center of attention right from when curriculum came into attention of educational institutions. thus everywhere in the world in educational institutions curricula and syllabi are evaluated and revised based on the goals, the needs, existing content, etc.. in iran any curriculum is designed in a committee of specialists and...

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

in the past couple of decades sociocultural theory of sla and its implications in efl contexts have attracted attentions of research circles worldwide and aroused some controversies. firth and wagner (1997) have questioned the principles of the cognitive view which gives importance to mental constructs in favor of sociocultural view which highlights social and contextual constructs. but if soci...

anxiety is one common disorder during childhood. in curing anxiety disorders, there are different types of psychological remedies, pharmotherapy, family therapy, and music therapy that can improve the individual’s anxiety, but we need some other remedies to improve social and emotional relationship and interactions. considering the importance of curing the anxiety disorders, the effect of sand ...