نتایج جستجو برای: are used to reduce soil erosion
تعداد نتایج: 11167584 فیلتر نتایج به سال:
in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...
introduction soil losses and erosion is one of the main causes of fertility decreasing, sedimentation in river cannels and irrigation canals, decreasing of storage capacity in dams, increasing of floods frequency, environmental pollution and it prevents from stable development. more than 70% of iran land is covered with arid and semi-arid areas. soil erosion as one of the main causes of soil de...
the present study aimed to investigate representation of discourse markers and metadiscourse markers in conversations and readings of general elt coursebook series used in the language centers of iran. to this aim, four elt coursebooks popularly taught in language centers of this country were analyzed based on fung and carter’s (2007) framework regarding discourse markers and hyland’s (2005) fr...
abstract the present research is prepared to study the culture of tea consuming among iranian. the case group which was statistically used for this study was people of lahijan , about four hundred wich were chosen according to their age , gender , education and occupation , randomly selected to fill the questionnaire . then the data collected through the questionnaire was analyzed according ...
learning-oriented assessment seeks to emphasise that a fundamental purpose of assessment should be to promote learning. it mirrors formative assessment and assessment for learning processes. it can be defined as actions undertaken by teachers and / or students, which provide feedback for the improvement of teaching and learning. it also contrasts with equally important measurement-focused appro...
Switzerland’s 2014 “Agricultural Report” asserts that the fertility of Swiss agricultural lands is compromised in the long term, and that one of the major causes is water erosion. Yet, the problem of soil erosion is not recent. It has been studied for more than fifty years and included in agroenvironmental policy-making for more than twenty years. However, despite significant improvements, expe...
In the United States, the USDA Natural Resources Conservation Service (NRCS) is the primary agency charged with the task of reducing wind erosion associated with production agriculture. The NRCS has used the Wind Erosion Equation (WEQ) (Woodruff and Siddoway, 1965) to assess the effects of field management on the potential for wind erosion for the last two and a half decades. The WEQ uses input...
Water is the most production limiting factor for dryland cropping systems in semiarid Great Plains environments. Evaporation is responsible for the greatest amount of water loss and management practices such as notill have been adopted to reduce evaporative losses. Less is known about the magnitude of water loss due to runoff. An objective of this study is to estimate an expected range in rainf...
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