in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

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...

abstract pragmatics is the study of communicative action in its sociocultural context. communicative action includes not only using speech acts (such as apologizing, complaining, complimenting, and requesting), but also engaging in different types of discourse and participating in speech events of varying length and complexity. the present study aimed to investigate the assessment of pragm...

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...

within communicative, interactive, and learner-centered framework of language teaching and learning, students need to learn four skills of listening, speaking, reading, and writing for their educational success. but of all the language skills, reading enjoys a paramount significance in so many second or foreign language academic contexts. in spite of its importance, language learners still have...

asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...

the world wide web becomes very popular recently and plays an influential role in english learning. by burgeoning role of source-based writing as partial fulfillment of tefl courses and vast use of the internet, lack of empirical studies to explore these areas is obvious. this study aimed to explore the effect of the amount of familiarity with the web (internet literacy) on junior english stude...

the main purpose of the present study was to investigate the relationship between listening proficiency and metacognitive listening strategies awareness among low, mid, and highly self-regulated students. three hundred and seventy one efl students participated in this study (all grade 3 and 4 high-school students who were studying in khansar in academic year 1391-92). to gather the data, three ...

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...