1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...

in order to examine the ecological conditions and characteristics of fraxinus excelsior l. in the northern forests of iran 6 main areas as well as some miscellaneous ones , have been selected in the region respectively in : lomir2, shafaroud , park - e-noor , ahlam , alandan and noor.

a simple, sensitive and selective method for solvent extraction and spectrophotemetric determination of lanthanum (ii) europium (iii), and cerium (iii) is described , the rare earth metals are extracted into chloroform solution of n-phenylbenzohydroxamic acid (pbha) at ph 9-10 various parameters are studied to optimize the extraction conditions. the molar absorptivity is found to increase from ...

rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

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...

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

introduction acetic acid bacteria are large group of obligate aerobic gram negative bacteria with the ability to oxidize ethanol to acetic acid (1). they are widely distributed in natural habitats and classified in family acetobacteraceae. members of this family are useful in industrial production of vinegar(2). acetic acid bacteria (aab) can use substrates as glucose, ethanol, lactate or glyc...

there is no doubt that human being needs to become integrated with industry and industry needs to be progressed, daily. on the other hand, serious events in industrial units specially in oil industries has been shown that such damages and events are industry related ones. the consequence of such events and damages which resulted in chemical and poisoned explosions and loss of life and property ...

the rise and stublishment of safavid dynasty was depend on triangle of tasavof, tashayo and royalty, kings legitimized their power upon these. therefore for the understanding the functions of that period we must explore the role of this elements. although application and emphsise upon dignities such as; complete mentor (morshede kamel), deputy of absent imam (nayebe imame ghayeb), and god’s sha...