نتایج جستجو برای: protection
تعداد نتایج: 179842 فیلتر نتایج به سال:
conclusions the state of observed radiation protection principles was relatively in the weak level in the studied radiology departments especially in facilities such as ventilation system, radiography entrance, and darkroom situation. more important reason was usage changing of sections as radiology billet from related organizations. results the mean of radiation protection in the studied radio...
biodiversity degradation, lose of wetlands and arsenic pollution are becoming the major environmental threats of bangladesh. huge number of population, corruption and lack of capacity of the governmental agencies are deteriorating the over environmental condition of bangladesh. this paper reports the findings of ngos and their role in protection of wetlands of bangladesh. ministry of environmen...
catalytic amount of ce(iv) as ceric triethylammonium nitrate (ctean) in dichloromethane or acetone can bring about an efficient tetrahydropyranylation of different types of alcohols to afford the corrsesponding tetrahydropyranyl ethers in high yields. deportection of tetrahydropyranyl ethers can also be achieved efficiently in the presence of this catalyst in methanol.
in multi-step organic syntheses, the protection and deprotection of tetrahydropyranyl (thp) ethers is one of the most frequently used methods. over the years, different methods have been used from various catalytic systems for the protection of hydroxyl groups as thp ethers and their deprotection. herein we have reported that various alcohols and phenols have been efficiently converted to the c...
the protective effects of exogenous melatonin on nicotine-induced changes in mouse ovarian follicles
background: nicotine exposure causes impaired fertility and ovarian dysfunction. the aim of this study was to investigate the possible protective role of melatonin, which is known as an antioxidant agent on altered ovarian functions upon nicotine exposure. methods: a total of 32 female adult nmri mice were divided randomly into four groups (n=8). the control group received vehicle, while group ...
background: protecting households against financial risks is one of objectives of any health system. in this regard, iran's fourth five year developmental plan act in its 90th article, articulated decreasing household's exposure to catastrophic health expenditure to one percent. hence, this study aimed to measure percentage of iranian households exposed to catastrophic health expenditures and t...
the fruit essential oil of ferula gummosa boiss., umbelliferae, which has been used as an antiepileptic remedy in iranian traditional medicine, was evaluated for anticonvulsant activity against experimental seizures. the essential oil had no effect against seizures induced by maximal electroshock. however, it protected mice against pentylenetetrazole-induced tonic seizures. the protective dose ...
purpose : to compare the protection of eyes against visible light (vl) and ultraviolet radiation (uvr) by sunglasses available through the iranian optician trade ::::union:::: (iotu) shops and those provided by miscellaneous vendors. methods : totally, 353 pairs of sunglasses, including 188 pairs from iotu shops and 165 pairs from miscellaneous vendors were selected based on systematic random s...
1,1-Diacetates(acylals) were prepared by direct condensation of various aldehydes with acetic anhydride using dipyridine cobalt chloride (CoPy2Cl2) as an efficient and green catalyst under solvent-free conditions at room temperature. The important features of this catalyst method are that the catalyst is solid, stable at high temperatures, soluble in water, stable in air, immiscible in common o...
The undesired operation of zone 3 may be one of the most conspicuous protective relay features due to the incorrect zone 3 relay operations which have been conducive to the severity of blackouts. Therefore, determining the accurate zone 3 setting of the distance relay is deemed to be necessary. This paper focuses on the development of a new technique for calculating zone-3 setting of distance r...
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