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...

the main purpose of the present study was to investigate the relationship between listening proficiency and metacognitive listening strategies awareness among low, mid, and highly self-regulated students. three hundred and seventy one efl students participated in this study (all grade 3 and 4 high-school students who were studying in khansar in academic year 1391-92). to gather the data, three ...

this study focuses on jane austens representation of her heroines in two of her novels: pride and prejudice, and mansfield park. i have concentrated only on a single idea: how jane austen takes her heroines through a course of psychogical reformation to which almost everything else in her novel is subsidiary. although i have discussed only pride and prejudice, we can trace austens carefully pla...

in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

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...

fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

the purpose of the present study is to find out whether bilinguals of khuzestan-arab origin or monolinguals of iranian origin code-switch during learning or speaking english and which group is more susceptible to code-switch. to this end, the students of 24 classes from high schools and pre- university centers were screened out, and interviewed and their voices and code-switchings were recorded...

a problem of computer vision applications is to detect regions of interest under dif- ferent imaging conditions. the state-of-the-art maximally stable extremal regions (mser) detects affine covariant regions by applying all possible thresholds on the input image, and through three main steps including: 1) making a component tree of extremal regions’ evolution (enumeration), 2) obtaining region ...

today, scouring is one of the important topics in the river and coastal engineering so that the most destruction in the bridges is occurred due to this phenomenon. whereas the bridges are assumed as the most important connecting structures in the communications roads in the country and their importance is doubled while floodwater, thus exact design and maintenance thereof is very crucial. f...

many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...