in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

introduction acetic acid bacteria are large group of obligate aerobic gram negative bacteria with the ability to oxidize ethanol to acetic acid (1). they are widely distributed in natural habitats and classified in family acetobacteraceae. members of this family are useful in industrial production of vinegar(2). acetic acid bacteria (aab) can use substrates as glucose, ethanol, lactate or glyc...

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

abstract because of the many geopolitical, geo economical and geo strategically potentials and communicational capabilities of eco region, members can expand the convergence and the integration in base of this organization that have important impact on members development and expanding peace in international and regional level. based on quality analyzing of library findings and experts interv...

cohesion is an indispensable linguistic feature in discourse analysis. lexicald such a differe cohesion and conjunction in particular as two crucial elements to textual cohesion and comprehension has been the focus of a wide range of studies up to now. yet the relationship between the open register and cohesive devices has not been thoroughly investigated in discourse studies. this study concen...

dendrimer synthesis strategies now provide virtual control of macromolecular nanostructures as a function of size and surface/interior functionality. these strategies involve the covalent assembly of hierarchical components reactive monomers , branch cells or dendron’s around atomic or molecular cores according to divergent/convergent dendrite branching principles.combinon of two or more dendri...

iv abstract this study examined the linguistic behaviors of two iranian efl teachers each of them teaching learners of two similar proficiency levels, a beginner level and an intermediate level, to investigate the relationship between the learners proficiency levels and the amounts and purposes for l1 use by the two teachers. the study was carried out to investigate whether there were differe...

abstract following innovations in the field of elt, a new topic which has recently attracted a lot of attention is metaphor analysis. although this area of research is still in its infancy in elt, it seems that the idea can shed more light on the puzzle of english language learning and teaching. therefore, the major aim of this study is to analyze language learning and teaching in formal a...

the application of a comprehensive model of communicative language ability (cla) to language teaching and testing has always been an imperative in l2 education since hymess proposal of communicative competence in the 1970s. recent l2 research has clearly underscored the importance of sufficient pragmatics representation as an essential component of cla in pedagogical and testing practices in l2...

simplification universal as a universal feature of translation means translated texts tend to use simpler language than original texts in the same language and it can be critically investigated through common concepts: type/token ratio, lexical density, and mean sentence length. although steps have been taken to test this hypothesis in various text types in different linguistic communities, in ...