نتایج جستجو برای: in a buffer solution

تعداد نتایج: 20406087  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد 1388

plagiarism in esl/efl learning contexts has been established as a dynamic and multi-layered phenomenon and has become a topic engaging many researchers in a heated debate in recent years. comparisons of student-generated texts with their source texts have shown that students rely on source texts in their writings and copying is a major strategy used by both l1 and l2 writers. in our country a...

پایان نامه :دانشگاه تربیت معلم - سبزوار - دانشکده علوم انسانی و پایه 1393

burnout is a response to the chronic work stress which is prevalent mostly among the people who do people job, like teaching. the purpose of this study was to develop a valid and reliable instrument that can measure burnout in foreign language teachers. although some widely used instruments were developed before which measured burnout in teachers, a specific instrument which include specific sy...

AR Shafaati BJ Clark

Two Capillary Zone electrophoresis (CZE) methods were developed in this study, one using an acidic buffer (sodium citrate pH = 2.5) and the other using a basic buffer (sodium tetraborate pH = 9.8). The two methods were compared on the basis of repeatability and reproducibility of results and the CZE method developed with the basic buffer was then selected for further studies. The method was ful...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه مازندران - دانشکده علوم انسانی و اجتماعی 1388

abstract the present study was conducted to examine the effect of proficiency on students interaction while carrying out the grammar-based task(s) in collaboration. in particular, the study examines whether the level of proficiency affects the learners’ focus of attention to grammatical and lexical features. the study takes a further step and examines whether there is any difference in the use...

The characterization of and construction of a new optical sensor based on the immobilization of Pyrocatechol Violet on a triacetylcellulose membrane was described to for the determination of bismuth (III) in real samples. The interaction between sensing membrane and bismuth (III) was caused at pH 3.80 in acetate buffer solution and the color changed from yellow to blue along with the appearance...

Journal: :iranian journal of pharmaceutical research 0
maryam azimi department of pharmaceutical biotechnology, school of pharmacy, shahid beheshti university of medical sciences nastaran nafissi-varcheh department of pharmaceutical biotechnology, school of pharmacy, shahid beheshti university of medical sciences mohammad ali faramarzi department of pharmaceutical biotechnology, faculty of pharmacy & biotechnology research center, tehran university of medical sciences reza aboofazeli department of pharmaceutics, school of pharmacy, shahid beheshti uni. med. sci.

the aim of this study was to develop a microemulsion system as a medium for laccase-catalyzed reactions. phase behavior studies were conducted by constructing partial pseudo-ternary phase diagrams for systems comprising of cetyltrimethylammonium bromide (ctab), various organic solvents as the oil phase (i.e., hexane, cyclohexane, heptane, octane, isooctane, toluene, isopropyl myristate), two co...

Journal: :journal of the iranian chemical research 0
ahmad rouhollahi department of chemistry, faculty of science, k.n. toosi university of technology, p.o. box 16315- 1618, tehran, iran reza moradkhani department of chemistry, faculty of science, k.n. toosi university of technology, p.o. box 16315- 1618, tehran, iran hamid shirkhanloo department of chemistry, faculty of science, k.n. toosi university of technology, p.o. box 16315- 1618, tehran, iran jahan b. ghasemi department of chemistry, faculty of science, k.n. toosi university of technology, p.o. box 16315- 1618, tehran, iran

in this work a rapid and selective procedure for separation and preconcentration of lead(pb2+) before determination by electrothermal atomic absorption spectrometry (etaas) wasdeveloped. the procedure is based on the electrodeposition on a graphite probe modified withpalladium. the lead was deposited from acetate buffer solution at ph 5.5. various parameters,such as ph of solutions, deposition ...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

writing as a productive skill requires practice in the basic sub-skills of vocabulary and grammar. in fact, grammar has been viewed as the core of programs in writing classes to help the students put the elements of sentence together and combine sentences of specific lengths to come up with an error-free work of art. conceptualizing l2 writing in this way introduces writing as a product and enc...

پایان نامه :دانشگاه امام رضا علیه اسلام - دانشکده ادبیات و علوم انسانی 1393

this research aims at answering the questions about translation problems and strategies applied by translators when translating cultural concepts. in order to address this issue, qualitative and quantitative study were conducted on two groups of subjects at imam reza international university of mashhad. these two groups were assigned as beginner and advanced translation students (10 students). ...

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