تهیه ترکیب فسفرتری کلرید بااستفاده از واکنش فسفر سفید(زرد) و گاز کلر در فاز محلول و درمقیاس آزمایشگاهی موردمطالعه قرارگرفت .پس از انتخاب مناسبتر روش و انتخاب بهترین شرایط کوشش درجهت طراحی واحد نیمه صنعتی انجام شد و توانستیم دراین راستا به تولید 10 کیلوگرم درساعت باخلوص 99/5 درصد برسیم . abstract the preparation of phosphorous trichloride by the reaction of white phosphorous and chlorine gas in ...

abstract recent studies suggest that prelistening activities play an important role in the development of listening comprehension (e.g. long 1990;chiang and dunkel 1992; schmidt-rinehart 1994; jensen and hansen 1995; robinson et al., 1995; buck, 1995; foster and skehan,1996; teng 1996; robinson, 2001; chang and read 2006). in line with previous studies and to shed light on a new aspect of sche...

abstract amino acids are building blocks of proteins, and play a vital role in living beings existence and their functionality. the interaction of these compounds with metal ions is of great importance to biochemists, and chemists, because their functions can be utilized as a model in understanding enzymes mechanism for transport of metal ions to tissues. among twenty essential amino acids w...

there are many approaches for solving variety combinatorial optimization problems (np-compelete) that devided to exact solutions and approximate solutions. exact methods can only be used for very small size instances due to their expontional search space. for real-world problems, we have to employ approximate methods such as evolutionary algorithms (eas) that find a near-optimal solution in a r...

abstract target-oriented approaches to translation studies are regarded as recent theories of translation. one of the most famous theories among these approaches is descriptive translation studies presented by toury (1995). this theory gives a new dimension to translation studies and gives importance to the descriptive rather than prescriptive studies. it also identifies three sets of transla...

to teach english adequately, qualified teachers are needed. unfortunately, there are still teachers who are teaching english without an academic degree in tefl. it is necessary for teachers to have a major in english to have subject knowledge, but it is not sufficient. teachers need to have an understanding of the social, cultural, moral, ethical, and pedagogical issues of education and practic...

growing demands and requires of high data rate systems cause significant increase of high frequency systems for wideband communication applications. as mixers are one of the main blocks of each receivers and its performance has great impact on receiver’s performance; in this thesis, a new solution for ku-band (12-18 ghz) mixer design in tsmc 0.18 µm is presented. this mixer has high linearity a...

in this study reference as one of the five cohesive devices in the achievement of textuality in english and persian narrative/descripitive written texts is focused on and analysed . to do so , the theoretical framework elaborated by halliday and hasan (1976) and its version adapted by the writer to match the sub-types of reference in farsi are applied to the analysis of reference in english and...

abstract the aim of the present study is to explore the impact of the cognitive reading strategy instruction on learners reading self-efficacy and their reading achievement. in order to fulfill this purpose, from 120 participants, 90 intermediate efl learners as an experimental group were chosen from three different educational settings namely, yazd university, yazd science and art un...

abstract sensitive and precise voltammetric methods for the determination of trace amounts of furaldehydes, mainly as furfural (f) and 5-hydroxymethyl-2-furaldehyde (hmf), in waste waters and other matrices is described. determination of total furaldehyde at < ?g g-1 levels in alkaline buffered aqueous media was individually investigated. by the use of ordinary swv and adsorptive square wave ...