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...

in this thesis our aim is to construct vector field in r3 for which the corresponding one-dimensional maps have certain discontinuities. two kinds of vector fields are considered, the first the lorenz vector field, and the second originally introced here. the latter have chaotic behavior and motivate a class of one-parameter families of maps which have positive lyapunov exponents for an open in...

in one pole of the continuum of language learning, theoreticians and practitioners traditionally consider english as english as a second language or english as a foreign language. however, in the other pole of this continuum where english is thought of as the most effective tool for international communication, it is referred to as a lingua franca. those who favor an approach to english growing...

there is no doubt that human being needs to become integrated with industry and industry needs to be progressed, daily. on the other hand, serious events in industrial units specially in oil industries has been shown that such damages and events are industry related ones. the consequence of such events and damages which resulted in chemical and poisoned explosions and loss of life and property ...

abstract this study is carried out to determine the chemical composition in the three vegetative stages of the haloxylon sp., degradation parameters, with adding naoh and ca(oh2 ). for this purpose, in may and october and january 2010 enough some haloxylon sp. of the ammary area was prepared. crude protein and ash percentage are decrease, neutral detergent fiber percentage with pragress stage ...

abstract in a protocol analysis of second language writing from 20 adult english as a foreign language (efl) iranian students, this research observed how language-switching (l-s), i.e., first language use in l2 writing, was affected by l2 proficiency. switching interactively between first (l1) and second (l2) languages has been recognized as one of the salient characteristics of l2 writing....

even though, to date, a lot of studies have been conducted on the subject of politeness theory, there are very few studies regarding the applicability of this theory to translation between english and persian which shows the reason behind conducting the present study. this study was carried out with the aim of highlighting whether there is any difference between english and persian methods of u...

‏‎for the first time nakayama introduced qf-ring. in 1967 carl. faith and elbert a. walker showed that r is qf-ring if and only if each injective right r-module is projective if and only if each injective left r-modules is projective. in 1987 s.k.jain and s.r.lopez-permouth proved that every ring homomorphic images of r has the property that each cyclic s-module is essentialy embeddable in dire...

when we return to the concept of poetry and the age-old discussion about the uselessness or the usefulness of the poets to the private and public state of human beings, originating from plato and aristotles views about poets respectively, there emerges the question of the role of poetry in human beings lives. in the same manner, with the advance of technology and the daily progress and improvem...

an investigation into oral interaction in language classes: a conversation analytic point of view the aim of this thesis is to analyze the interaction between language teachers and students in english language institutes. this work is done in the context of yasuj city. learning another language, which is in most cases english, involves many variables. one of these variables is the linguistic...