نتایج جستجو برای: grazing density and loss of rangelands quality were main indicators affecting desertification process

تعداد نتایج: 24152828  

Journal: :مرتع و آبخیزداری 0
محسن سرشاد قهفرخی دانش آموخته کارشناسی ارشد مرتعداری دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران سید علیرضا موسوی استادیار دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران سعید سلطانی دانشیار دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران سعید پورمنافی استادیار دانشکده منابع طبیعی، دانشگاه صنعتی اصفهان، ایران

natural resources are valuable capitals for all nations. rangelands as the most extensive natural ecosystems in iran provide numerous services, including fodder production and red meat supply, soil conservation and water regulation. although uncontrolled exploitation of these resources has imposed much pressure and caused many losses within the ecosystems. impacts of overutilization of nomadic ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

seismic retrofit strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials and methods. it can be observed that new approaches to deal with more lateral forces are more innovative and more energy absorbent. in line with this, there is a growing trend toward the use of steel shear walls as a system with ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده ادبیات و علوم انسانی 1391

during the process of reading, sometimes learners use ineffective and inefficient strategies and some factors may influence their use of strategies. perhaps critical thinking is one of these factors. this study aims to identify those categories of reading strategies that are mostly used by iranian efl learners and to see if there is any significant relationship between the critical thinking abi...

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

abstract: country’s fiber optic network, as one of the most important communication infrastructures, is of high importance; therefore, ensuring security of the network and its data is essential. no remarkable research has been done on assessing security of the country’s fiber optic network. besides, according to an official statistics released by ertebatat zirsakht company, unwanted disconnec...

2016
Ya Wang Lihua Zhou

Sandy desertification is one of the most severe ecological problems in the world. Essentially, it is land degradation caused by discordance in the Social-Ecological Systems (SES). The ability to coordinate SES is a principal characteristic of regional sustainable development and a key factor in desertification control. This paper directly and comprehensively evaluates the ability to coordinate ...

Journal: :journal of rangeland science 2015
hamid niknahad gharmakher isa jafari foutami arezou sharifi

in recent years, rangelands have been regarded as potential carbon sinks. one of the most widely suggested options to sequester more c in rangelands is the restoration of the degraded rangelands through grazing the exclusion. in present study, the effects of exclusion on the carbon sequestration of gomishan rangelands were investigated. three transects were established in a key area inside and ...

Journal: :journal of rangeland science 2014
abolfazl sharifiyan bahraman hossein barani ahmad abedi sarvestani abolfazl haji mollahoseini

rangelands are known as one of the main income resources for their exploiters.in the recent century, management of iran rangeland has undergone vast transformationsbecause of vulnerable socio-economic conditions of pastoralists. a study was done toprovide a clear picture of the status and utilization of aq qala rangelands via assessinginternal and external environmental factors affecting the ut...

پایان نامه :وزارت بهداشت، درمان و آموزش پزشکی - دانشگاه علوم پزشکی و خدمات بهداشتی درمانی مشهد - دانشکده دندانپزشکی 1390

objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...

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 فردوسی مشهد - پژوهشکده ادبیات 1391

the major purpose of this study was to develop the translation teacher competency test (ttct) and examine its construct and predictive validity. the present study was conducted in two phases: a qualitative phase as well as a quantitative phase. in the first phase of the study, the author attempted to find out the major areas of competency required for an academic translation teacher. the second...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید