نتایج جستجو برای: water productivit
تعداد نتایج: 550740 فیلتر نتایج به سال:
the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so...
in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...
run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...
in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
پیشنهاد های زیادی توسط محققین برای کاهش انتشار دی اکسید کربن مطرح و اجرا شده است . یکی از بهترین روش ها، ذخیره سازی در ساختار های زمین شناختی زیر زمینی می باشد. ذخیره سازی وتزریق دی اکسید کربن در مخازن خالی نفت و گاز ، مخازن نفت و گاز برای eor و egr ،سفره های آب شور ، بستر های زغال سنگی و اقیانوس ها انجام می گیرد.کشور ایران دارای سازند های بزرگ نفتی و گازی می باشد.از این رو می توان از آن ها برا...
بهره گیری از روش های بهینه در طراحی شبکه های توزیع آب شهری در کشور ما هنوز کاملاً نو و برای کارشناسان این بخش عموماً ناشناخته است. اکثر طراحان انتخاب اقتصادی قطر لوله ها را امری وقت گیر، محدودکننده و پیچیده می دانند و برای طراحی بهینه فقط از سرعت مجاز آب و یا یک میزان افت اصطکاکی استفاده می کنند. در این تحقیق یک نمونه از شبکه آبرسانی فضای سبز شهری طراحی شده موجود، انتخاب شده و بعد از آنالیز هیدرو...
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 ...
aims: bottled water is widely used in many countries and more than 100 different brands of bottled water are produced in iran. the aim of the present research was to assess the chemical compound of some iranian brands of bottled water and compare them with the mention information on their labels. instrument & methods: this descriptive study was performed during march to december 2012 on the...
main perennial rivers of gujarat, tapi, narmada, mahi and sabarmatiare meeting arabian sea in gulf of khambhat. the out flow of mahi river intothe sea is decreased due to construction of dams like bajaj sagar, kadana, panamand wanakbori weir. so, tidal effect of sea and sea water intrusion is beingincreased on landward side. moreover, due to erratic nature of rainfall andimproper management of ...
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