in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

چکیده : نظام انتخاباتی قواعد و چار چوب های به رسمیت شناخته شده ای است که بیانگر چگونگی تبدیل آرای مردم به مناصب و پست های سیاسی است. این نظام انتخابات باید به گونه ای عمل کند که نتیجه آن فراهم شدن مکانیسم و ساز و کار مطلوب و مناسب برای برگزاری انتخابات سالم و رقابتی باشد. به نظر می رسد نظام انتخاباتی جمهوری اسلامی ایران دارای ضعف ها و نواقصی است که به سبب آن ها نمی توان انتخابات مطلوب را برگزا...

Purpose: The aim of the current research is to write possible scenarios for the future of Iran's public libraries. Regarding the position and application of public libraries, they are considered as a communicative medium. Methodology: The effort is to offer scenarios that deal with the multiplicity and unpredictability of the future. The Two-on-Two model was used for determination of scenarios...

thermal barrier coatings (tbcs) are used to provide thermal insulation to the hot section components of gas turbines in order to enhance the operating temperature and turbine efficiency. hot corrosion and thermal shocks are the main destructive factors in tbcs which comes as a result of oxygen and molten salt diffusion into the coating. in this thesis atmospheric plasma spraying was used to dep...

asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...

Electron curtain accelerator is a type of low-energy electron accelerator, which plays an important role in many different industries such as printing, coating and packing to promote product quality, while reducing volatile organic compounds for protecting global environment. Electron emitter is one of the main components of this type of accelerators. Multi-filament cathodes and grid structures...

after the soviet union dissolution, a chaotic period was begun in the russia. russia lost its glory and felt disgrace. the first group of elites came to power under yeltsin; they tried to re-define russia’s identity as a european country and build a foreign policy on this baseline. therefore russia tried to become closer with the west especially with the u.s. according to their view the sovie...