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...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

abstract cooperative learning refers to small groups of learners working together as a team to solve a problem, complete a task, or accomplish a common goal. in a cooperative environment one’s success is directly related to the success of other members because the focus on the individual shifts towards the group. to test the effectiveness of the method, using jigsaw technique, a study was cond...

during the process of reading, sometimes learners use ineffective and inefficient strategies and some factors may influence their use of strategies. perhaps critical thinking is one of these factors. this study aims to identify those categories of reading strategies that are mostly used by iranian efl learners and to see if there is any significant relationship between the critical thinking abi...

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

armenias geopolitics and its historical experience have had a determining impact on the character of its foreign policy .present-day armenia is a small, landlocked country with _11,620 square miles area armenias landlocked nature makes it dependent on the benevolence of its neighbors for access to the outside world a fact that gives it a sense of isolation and vulnerability. as it was indic...

the present paper deals with criminal issues. for example, legal injunction on the necessity of returning a deposit has a legal nature and legal injunction on the punishment of those who breach the trust has a criminal nature. existing social issues are the basis of classification of some instances into the issue, some of which are based on variation and others on quality. therefore, the motiva...

there is less published research about how teachers in efl contexts respond to students who are relatively less mature and less competent l2 writers. while writing researchers have examined various issues concerning peer and teacher response in writing-oriented classes, little research has centered on the effect of collaborative tasks particularly dictogloss on writing skills. output collaborat...

chapter one is devoted to a moderate discussion on preliminaries, according to our requirements. chapter two which is based on our work in (24) is devoted introducting weighted semigroups (s, w), and studying some famous function spaces on them, especially the relations between go (s, w) and other function speces are invesigated. in fact this chapter is a complement to (32). one of the main fea...