in this project, 4,4?-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a diacid, was prepared by the reaction of trimellitic anhydride (tma) with 4,4?-methylenebis(3-chloro-2,6-diethylaniline) (mcdea). the novel poly(amide-imide) (pai) was synthesized from the reaction of 4,4?-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a diacid with mcdea under green condition using ...

1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...

just as motivation is important in sla research, demotivation constitutes an important factor, too. there are many studies done on demotivation and burnout of teachers. many of these studies have been conducted on one or two aspects of english instruction. consequently, there are few studies which have been done on more than two aspects of english teaching. the aim of this study is to find out ...

there has been a gradual shift of focus from the study of rule systems, which have increasingly been regarded as impoverished, … to the study of systems of principles, which appear to occupy a much more central position in determining the character and variety of possible human languages. there is a set of absolute universals, notions and principles existing in ug which do not vary from one ...

oxidative addition reactions of 1,4-diiodo-butane and 1,3-diiodo-propane with [ptme2(ph2phen)]; in which ph2phen=4,7-diphenyl-1,10-phenanthroline, were studied in different solvents such as acetone and benzene.oxidative addition reaction of [pt me2(ph2phen)] with i(ch2)4i and i(ch2)3i produced the [pt me2i(ch2)4(ph2phen)i] (1a) and [pt me2i(ch2)3(ph2phen)i] (1b).all the platinum (iv) products w...

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 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 ...

this study compared the different effects of form-focused guided planning vs. meaning-focused guided planning on iranian pre-intermediate students’ task performance. the study lasted for three weeks and concentrated on eight english structures. forty five pre-intermediate iranian students were randomly assigned to three groups of guided planning focus-on-form group (gpfg), guided planning focus...

abstract the purpose of this study is twofold: on the one hand, it is intended to see what kind of noticing-the –gap activity (teacher generated vs. learner generated) is more efficient in teaching l2 grammar in classroom language learning. on the other hand, it is an attempt to determine which approach of the noticing-the-gap- activity is more effective in the long- term retention of grammar...

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...