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...

most specialists in the field of foreign language teachingconsiderreading skill as an interactive process between the reader’s prior knowledge and the text.accordingly, the activation of prior knowledge for an effective comprehension is very important. it is generally agreed that the pre-reading phase is the stage where this type of interaction and activation may be enhanced throughcertain stra...

nowadays in trade and economic issues, prediction is proposed as the most important branch of science. existence of effective variables, caused various sectors of the economic and business executives to prefer having mechanisms which can be used in their decisions. in recent years, several advances have led to various challenges in the science of forecasting. economical managers in various fi...

in this thesis, ‎‎using‎‎ ‎concept‎s‎ ‎of‎ ‎wavelet‎s‎ ‎theory ‎‎‎som‎e‎ ‎methods‎‎ ‎of‎ ‎th‎e ‎solving‎‎ ‎optimal‎‎ ‎‎con‎tr‎ol‎ problems ‎(ocps)‎‎. ‎g‎overned by time-delay systems is investigated. ‎th‎is‎ thesis contains ‎tw‎o parts. ‎‎first, the method of obtaining ‎o‎f ‎the‎ ‎‎ocps‎ in time delay systems by linear legendre multiwavelets is ‎ ‎presented‎.‎‎‎‎ the main advantage of the meth...

abstract:‎ literature is said beautiful words of poetry or prose that excites reader’s or listener’s feel. certainly, to ‎be effective, such a text should have certain characteristics. the four elements of the literature: thought, ‎imagination, emotion and style make a text to be literary and effective. emotion and imagination are ‎specific elements of literary texts, while thought and style a...

abstract in the present research solution of chalcopyrite in sulfuric acid in hydrometallurgy method using electrochemistry with cyclic voltammetry technique has been investigated. the value of maximum reduction peak current of copper ions represents the measure of solubility. in this research different parameters temperature, potential, potential exert time, chalcopyrite concentration, sulfur...

abstract following innovations in the field of elt, a new topic which has recently attracted a lot of attention is metaphor analysis. although this area of research is still in its infancy in elt, it seems that the idea can shed more light on the puzzle of english language learning and teaching. therefore, the major aim of this study is to analyze language learning and teaching in formal a...

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...

as some definitions show, idioms are expressions whose meanings cannot be obtained from individual words. in every society, people use their own conceptions and feelings through different idioms and expressions. so every culture and society has their own idioms. some scholars proposed methods for translating idioms but baker’s strategies are very important and constructive. this research tried ...

introruction khawf in(iran)-herat and mazaresharif and shirkhan bandar in (afghanistan)-dushanbe in (tajikistan)_(kirgizstan)-kashghar in(china) project railway network is under construction that it is as a significant corridor for revitalizing silk road corridor in the region .at the present there are three different gauge in the region central asia with 1,520 mm gauge and turkey-islamic repu...