نتایج جستجو برای: changes in temperature and precipitation

تعداد نتایج: 21809460  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شاهد - دانشکده علوم پایه 1388

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده ادبیات و علوم انسانی 1393

from its emergence till present time marxist principles has undergone great changes since their promulgation by marx. many theorists and thinkers set at rectifying marxist tenets and introducing those of their own while others advocated its main concepts and attempted at improving them. among marxist philosophers who had an intensive study of marxs ideology, is louis althusser whose reflections...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده کشاورزی 1389

چکیده توان بالقوه تجاری سلولازها و کاربردهای گوناگون آن ها در بسیاری از صنایع انگیزه ای قوی برای تحقیق در این زمینه طی چند دهه گذشته بوده است. با توجه به کاربردهای فراوان این آنزیم در صنایع غذایی? در این پژوهش تصمیم به جداسازی ریزسازواره های تولید کننده سلولاز از خاک درختان انار، انگور، خرمالو و گردو حیاط دانشکده کشاورزی تربیت مدرس، گرفته شد. در این بین خاک درخت خرمالو به دلیل دارا بودن تعداد ...

Global temperatures have increased in the past 100 years by an average of 0.74°C (IPCC, 2013), with minimum temperatures increasing faster than maximum temperatures and winter temperatures increasing faster than summer temperatures (IPCC, 2013). Total annual rainfall tends to increase at the higher latitudes and near the equator, while rainfall in the sub-tropics is likely to decline and become...

Journal: :اقتصاد و توسعه کشاورزی 0
صادق خلیلیان کتایون شمشادی سید ابوالقاسم مرتضوی مجید احمدیان

agricultural sector will be most affected by climate change due to its extensive interaction with the environment. and as a result of changing production conditions, community welfare is changed. this study attempted at understanding the welfare effects of changes in climate parameters on the wheat product. therefore, the yield functions were initially estimated. supply, demand and import funct...

Gh.R. Roshan, S.W. Grab

We simulate the effect of climate change on water requirements of cold seasonwheat in various climatic zones of Iran. The research considers both observedclimate (temperature and precipitation) changes during recent decades (1960-2009)based on instrumental records and projected future changes to 2100 based on theMAGICC/SCENGEN 5.3 compound model. 20 General Circulation models are usedbased on a...

F. Cai N. Mi R.P. Ji S.J. Zhang X.L. Zhao Y.S. Zhang,

Water use efficiency (WUE) reflects the coupling of the carbon and water cycles and is an effective integral trait for assessing the responses of vegetated ecosystems to climate change. In this study, field experiments were performed to examine leaf WUE (WUEleaf) in response to changes in CO2 concentration and other environmental variables, including soil moisture and air temperature. We al...

Introduction Zayandeh-Rud basin in central Iran is a region with water problems. Zayandehrood River that originates from the Zardkuh Bakhtiary Mountain is the most important river of the region for the development of agriculture, and a supply for heavy industry and drinking water sectors and is very important in all of economic activities. In the last decade, the water resources of the basin h...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1388

abstract sensitive and precise voltammetric methods for the determination of trace amounts of furaldehydes, mainly as furfural (f) and 5-hydroxymethyl-2-furaldehyde (hmf), in waste waters and other matrices is described. determination of total furaldehyde at < ?g g-1 levels in alkaline buffered aqueous media was individually investigated. by the use of ordinary swv and adsorptive square wave ...

Journal: :فیزیک زمین و فضا 0
فاطمه برزگری دانشجوی دکتری، گروه مرتع و آبخیزداری، دانشکدۀ منابع طبیعی، دانشگاه یزد، مربی، دانشکده کشاورزی، دانشگاه پیام نور، ایران حسین ملکی نژاد دانشیار، گروه مرتع و آبخیزداری، دانشکدۀ منابع طبیعی، دانشگاه یزد، ایران

introductionit is expected that projected changes in the frequency and severity of extreme climate events, such as increased frequency of heat stress, droughts and flooding will have significant consequences on water resources. increasing pressure on water resources due to climatic and anthropogenic changes as well as increasing competition among users is recognized challenges worldwide. global...

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