in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

چکیده توان بالقوه تجاری سلولازها و کاربردهای گوناگون آن ها در بسیاری از صنایع انگیزه ای قوی برای تحقیق در این زمینه طی چند دهه گذشته بوده است. با توجه به کاربردهای فراوان این آنزیم در صنایع غذایی? در این پژوهش تصمیم به جداسازی ریزسازواره های تولید کننده سلولاز از خاک درختان انار، انگور، خرمالو و گردو حیاط دانشکده کشاورزی تربیت مدرس، گرفته شد. در این بین خاک درخت خرمالو به دلیل دارا بودن تعداد ...

in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...

this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...

current studies in second language (l2) learning have revealed the positive role of corrective feedback (cf) in both oral and written forms in different language features. the present study was an attempt to investigate the effect of both direct and indirect written corrective feedback (wcf) on the use of grammatical collocations in l2 writing. the study also sought to examine whether the effec...

this study investigated (a) the learners’ existing reading strategy repertoire, (b) the effect of instruction in reading strategies on learners’ strategic performance, and (c) the effect of explicit instruction in top-down reading strategies on reading comprehension ability of intermediate learners. the study was conducted with 40 intermediate efl learners in two groups of experimental and cont...

in solvo-hydrothermal method, xrd pattern was indicated presence of intermediate of ammonium octatmolybdate and ammonium tetramolybdate, which were changed to stble phase of ?-moo3 annealing. sem images were indicated nanoparticle with semispheical morphology and tem image was demonstrated nanoparticles with a diameter size of 25nm. also in impregnate method. the xrd pattern was shown high crys...

abstract this study evaluated and compared medical terminology and english for the students of medicine (ii) as two representatives of the textbooks available on the iranian market for teaching english to the students of medicine. this research was performed on the basis of a teacher’s and a number of students’ attitudes and the students’ needs analysis for two reasons: first, to investigate...

the aim of conducting this study was to investigate the foreign language learning needs of undergraduate economics students and business management students in faculties of social sciences of alzahra and azad naragh university. in the study, which was designed on the basis of a qualitative-quantitative basis using interviews and questionnaires, 146 female undergraduate business management as we...

in this thesis a calibration transfer method is used to achieve bilinearity for augmented first order kinetic data. first, the proposed method is investigated using simulated data and next the concept is applied to experimental data. the experimental data consists of spectroscopic monitoring of the first order degradation reaction of carbaryl. this component is used for control of pests in frui...