‏‎the main purpose of this research was to:1.develop a coking model for thermal cracking of naphtha.2.study coke inhibition methods using different coke inhibitors.developing a coking model in naphtha cracking reactors requires a suitable model of the thermal cracking reactor based on a reliable kinetic model.to obtain reliable results all these models shall be solved simultaneously.for this pu...

any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

abstract: research purpose: the purpose of this research is to identify academic databases assessment factors and criteria at law and political science majors. the necessity of this research is to distinguish academic databases assessment factors and criteria and to identify the most important ones and rank them in order to select an appropriate database according to students’ and faculty memb...

this research study aimed to investigate the relationship between field-dependence/independence cognitive style and vocabulary learning strategies among iranian efl learners. ninety participants majoring in english translation at arak university were chosen. the participants were classified into two groups of field-dependent and independent based on the results of group embedded figure test (ge...

چکیده : هدف پژوهش حاضر، تعیین نقش واسطه‏ای اعتماد سازمانی در رابطه ی بین عدالت سازمانی و یادگیری سازمانی به روش تحلیل مسیر می‏باشد. برای این منظور با استفاده از روش نمونه گیری تصادفی ساده 1?0 نفر از کارکنان اداره ورزش و جوانان استان فارس انتخاب و به پرسشنامه های متشکل از ابعاد یادگیری سازمانی، عدالت سازمانی و اعتماد سازمانی پاسخ دادند. نتایج پژوهش به طور کلی نشان داد که رابطه ی عدالت سازمان...

this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...

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...

abstract: one of the most visited & important spaces in different countries by tourist are urban areas. the old tehran which major part is located in district 12 is historical showcase of the capital, but, its hiidden cultural attraction is not used as it should be. this thesis occasionally engage in studying the efficacy of correct installation of travel guide boards in welfare & easily acc...

abstract the present study tried to investigate the effect of visual aids (films) on the development of the speech act of disagreement among iranian efl intermediate learners. to this end, the researcher selected 40 homogeneous intermediate learners based on their scores on oxford placement test. .the subjects then divided into control group and experimental group. both classes were tested by ...

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...