چکیده واکنش تشکیل کمپلکس بین کاتیون اورانیل با لیگاند درشت حلقوی ان – فنیل – آزا – 15 کرون – 5 (pha15c5) در مخلوط های دو جزئی استونیتریل - متانول (an – meoh) ، استونیتریل – بوتانول (an – buoh )، استونیتریل – دی متیل فرمامید (an – dmf) و متانول – پروپیلن کربنات (meoh – pc) در دماهای مختلف با استفاده از روش هدایت سنجی مورد بررسی قرار گرفت. در اکثر موارد، استوکیومتری کمپلکس از نوع 1:1 ( لیگاند :...

in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

in this thesis our aim is to construct vector field in r3 for which the corresponding one-dimensional maps have certain discontinuities. two kinds of vector fields are considered, the first the lorenz vector field, and the second originally introced here. the latter have chaotic behavior and motivate a class of one-parameter families of maps which have positive lyapunov exponents for an open in...

abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...

from its emergence till present time marxist principles has undergone great changes since their promulgation by marx. many theorists and thinkers set at rectifying marxist tenets and introducing those of their own while others advocated its main concepts and attempted at improving them. among marxist philosophers who had an intensive study of marxs ideology, is louis althusser whose reflections...

the present research was conducted to explore the effect of employing two language teaching approaches, i.e. schema-based instruction (sbi) and translation-based instruction (tbi), on vocabulary knowledge, structure and reading comprehension ability of forty one female students learning english in grade one senior high school in rivash, kuhsorkh, iran. while sbi focuses on schemata, i.e. words ...

the present research was conducted to accomplish two purposes. firstly, it aimed to explore and describe schematic structure or what halliday and hassan (1989, p.64) have called “generic structure potential” (gsp) of american english, iranian persian and iranian english newspaper editorials within systemic functional linguistics. secondly, a quantitative cross-comparison was made to investigate...

the present study sought to examine whether a task-based approach could have an impact on raising awareness of collocations. moreover, it sought to investigate the facilitative role of consciousness-raising tasks of collocations in the communicative instances of use. to this end, 68 intermediate learners of english were selected via a placement test. the participants were taught with classroom ...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...

as the canon is shaped by white male standards rewriting the canonical works of literature is one of the ways through which postcolonial writers subvert the authority of the masters. writing in the language of the masters the colonized writers use the very suppressive tool in the hands of the masters i.e. their language to question the validity of their norms. regarded by most critics to be the...