نتایج جستجو برای: uniformity coefficient

تعداد نتایج: 183085  

Journal: :journal of agricultural science and technology 2011
m. jafari a. hemmat m. sadeghi

external fluted feed rolls are commonly used in grain drills. the fluted feed roll meters a volume of seeds and does not singulate the seeds as do the precision planters; therefore, there will be inherent variation in the number of seeds delivered per unit of time. this research was conducted to investigate the effect of seed meter drive shaft and ground speeds and outlet positions in a grain d...

2008
Xingye Zhu Shouqi Yuan Hong Li Junping Liu

The Complete fluidic sprinkler was originally created by China. Irrigation uniformity in no-wind conditions was studied in this paper. Radial water distribution for complete fluidic sprinkler type 10 was got by experiment. MATLAB was used to establish computation program to change the radial data into net data. Three-dimensional water distribution figures for single sprinkler and combined sprin...

Journal: :چغندرقند 0
حمیدرضا سالمی استادیار پژوهش بخش تحقیقات فنی و مهندسی کشاورزی- مرکز تحقیقات کشاورزی و منابع طبیعی استان اصفهان محمدرضا جهاداکبر مربی پژوهش بخش تحقیقات چغندرقند- مرکز تحقیقات کشاورزی و منابع طبیعی استان اصفهان علیرضا نیکویی استادیارپژوهش بخش تحقیقات اقتصادی، اجتماعی و ترویجی- مرکز تحقیقات کشاورزی و منابع طبیعی استان اصفهان

due to the scarcity of water resources, the need for sustainable development of drip irrigation tape is essential in iran. a number of drip irrigation tape systems used in sugar beet fields of isfahan and chahar mahal va bakhtiari provinces were evaluated and were compared with furrow irrigation methods in two consecutive years. the actual water use efficiency (wuesy, wuewsy) in lower quarter, ...

Journal: :journal of water sciences research 2013
j bazargan h.r eskandari

filter is one of the main components of embankment dams. by a simple but effective performance, filter protects the dam against erosion and soil scouring in impervious core caused by leakage (piping) and makes it safe. interaction between filter and erodible base soil is a complex phenomenon which is dependent upon several factors, and has challenged researchers for better understanding the fil...

Journal: :تحقیقات آب و خاک ایران 0
سعید زمانی دانشجوی کارشناسی ارشد دانشکدة کشاورزی دانشگاه ارومیه جواد بهمنش دانشیار دانشکدة کشاورزی دانشگاه ارومیه کامران زینال زاده استادیار دانشکدة کشاورزی دانشگاه ارومیه

increasing water distribution uniformity in micro irrigation systems has been an important subject in applied researches. despite considerable progress in emitters’ construction, some research reports refer to their incapability in water distribution uniformity. in order to achieve greater uniformity in micro irrigation, it is necessary to manufacture emitters with low variation in manufacturin...

Journal: :تحقیقات آب و خاک ایران 0
محبوبه سادات ملائی دانشجوی سابق کارشناسی ارشد علی مهدوی مزده استادیار گروه مهندسی آب دانشگاه بین المللی امام خمینی (ره) علیرضا وطن خواه استادیار گروه مهندسی آبیاری و آبادانی دانشگاه تهران

in this study, hydraulic properties of low pressure drip irrigation systems were studied under laboratory conditions and using of the pipes that exist in iran. therefore, effect of various heads from 0.45 to 1.8m was evaluated for lateral pipe with outside diameter 32mm and length of 16, 30, 60 and also the lateral pipe with length 16 and outside diameter of 16, 20, 25 and 32mm, on hydraulic ch...

2007
Jiří Militký Václav Klička

The main aim of this contribution is comparison of method for evaluation of nonwovens surface uniformity based on the data in the form of rectangular arrays (quadrat method). These data can be obtained from digital images where the variation of mass is characterizes by the variation of grey level image. The evaluation of uniformity is based on the variation coefficient model, ANOVA model and sp...

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