‏‎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...

the history of plant’s used for mankind is as old as the start of humankind. initially, people used plants for their nutritional proposes but after the discovery of medicinal properties, this natural ?ora became a useful source of disease cure and health improvement across various human communities. berberis vulgaris is one of the medicinal plants used in iranian traditional medicine. berberis ...

while performance-based language assessment has led to an increased authenticity and content validity in the practice of writing assessment, the reliability of ratings has become a major issue. research findings have shown different reactions by native english speaker (nes) and non-native english speaker (nns) teachers to students’ writings. the focus of this study is on investigating whether i...

this thesis attempts to measure learning styles, self efficacy and intrinsic motivation as predictors of iranian ielts reading comprehension. in order to address this issue, a quantitative study was conducted on some randomly selected intact students at ferdowsi university. these two groups were assigned as they were undergraduate (ba=91) and graduate (ma =74) students; they were all aged betwe...

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...

هدف تحقیق حاضر بررسی تاثیر نشانه های فرا گفتمان متنی بر فهم متون انگلیسی به وسیله ی زبان اموزان فارسی زبان است.این تحقیق علاوه بر این کوشیده است تا میزان اگاهی این زبان اموزان و نحوه ی تعامل انان را با متون خوانده شده در زبان انگلیسی به وسیله ی پرسش نامه ی تهیه شده بررسی کند.بر اساس محتوای یک متن انگلیسی یازده سوال درست /غلط طرح گردید و یک مرتبه با ان متن و یک مرتبه با نسخه ای که نشانه ها...

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...

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...

مقدمه: درعلم آمارسنتی همه پارامترها بوسیله مدلهای ریاضی ومشاهده های تجربی تعریف می شد. بعضی وقتها به نظر می رسد چنین فرضهایی برای مسائل زندگی روزمره سختگیرانه باشد.مخصوصا درصورتیکه ما با داده های زبان شناسی یا احتیاجاتی که صریح نباشند سرکارداشته باشیم. برای اینکه این مشکل را ازبین ببریم ازروش فازی استفاده می کنیم. تعریف مسئله: درمرحله اول از تحقیق درباره انواع مختلف از پدیده(زیستی-فنی-فیزیک...

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 ...