نتایج جستجو برای: water pressure

تعداد نتایج: 926030  

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2006
Eric Herbert Sébastien Balibar Frédéric Caupin

We investigate the limiting mechanical tension (negative pressure) that liquid water can sustain before cavitation occurs. The temperature dependence of this quantity is of special interest for water, where it can be used as a probe of a postulated anomaly of its equation of state. After a brief review of previous experiments on cavitation, we describe our method which consists in focusing a hi...

Journal: :مدیریت آب و آبیاری 0
سونیا زبردست دانش آموخته کارشناسی ارشد، گروه مهندسی آبیاری و زهکشی، پردیس ابوریحان، دانشگاه تهران علی رحیمی خوب دانشیار گروه مهندسی آبیاری و زهکشی، پردیس ابوریحان، دانشگاه تهران

according to the irrigation systems design standards, allowed pressure variation in lateral pipes is 20 percent. reasons for this rate selection, which since the 60's is performed, are not known. the increased changes in allowed pressure tubes to lateral pipes design, the increased sprinkling system required pressure and the increased nonuniform sprinkler distribution, so energy supply cos...

Journal: :journal of water sciences research 2012
h es-haghi sharabiani m gharavi

hydraulic conductivity variations around the boreholes in uniformly graded sands for cyclic water injection pressure have been evaluated by laboratory tests. prototype laboratory devices have been designed and constructed for this research. the cell has a capability to model the well, the boundary condition and to measure the hydraulic conductivity. while increasing water injection pressure, hy...

Journal: :محیط شناسی 0
محمدرضا جلیلی قاضی زاده استادیار دانشکده عمران، آب و محیط زیست، دانشگاه شهید بهشتی ضیاالدین ایدی دانشجوی دکتری سازه های هیدرولیکی، دانشگاه رازی

extended abstract abstract pressure management is an effective method for water demand management. for evaluation of the effects of pressure changes on leakage level of water networks, the favad equation is usually used. however, in this equation, exponent of pressure parameter (n) needs to be determined. for estimation of n, either some information about the leak opening is necessary or networ...

Water is the most essential component for sustaining lives of humans and other living creatures. Supplying potable water with adequate residual pressure is a fundamental responsibility of city administration, which they do during normal conditions. But sometimes, abnormal conditions are formed resulting pressure deficient conditions during the daily operations of water distribution networks. Th...

Journal: :تحقیقات نظام سلامت 0
مهربان صادقی دانشیار، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی شهرکرد، شهرکرد، ایران امین تاجی اشکفتکی دانشجوی کارشناسی ارشد، گروه مهندسی عمران، دانشکده فنی مهندسی، دانشگاه آزاد اسلامی واحد یاسوج، یاسوج، ایران حسن هاشمی کمیته تحقیقات دانشجویی، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران سعید حسینی مربی، گروه عمران، دانشکده فنی مهندسی، دانشگاه آزد اسلامی واحد یاسوج، یاسوج، ایران

abstract background: the pressure of consumption spots in eater supply systems is one of the most important hydraulic parameters can be used in optimized management of water distribution networks. since the pressure has some different effects on various parameters of the network management including its hydraulic functions, reliability, stability and leakage, its control is of great importance ...

There is a pressure tunnel as the type of structures, which is mainly used in the hydroelectric power industry and in order to design and construct these structures, there are many engineering challenges. One of these problems is the leakage around the tunnel and, consequently, erosion caused by excessive water pressure, and it will lead to instability and the destruction of pressure tunnels. T...

مصطفی‌ زاده, بهروز , کهنوجی, محمد ,

The emitter discharge is affected by parameters such as pressure, irrigation water temperature, manufacturer’s coefficient of variation, and emitter clogging. In order to study the effects of irrigation water temperature on emitter discharge and to determine the discharge-pressure variations and manufacturer’s coefficient of variations, an experimental trickle irrigation system was designed and...

ژورنال: علوم آب و خاک 2002
مصطفی‌ زاده, بهروز , کهنوجی, محمد ,

The emitter discharge is affected by parameters such as pressure, irrigation water temperature, manufacturer’s coefficient of variation, and emitter clogging. In order to study the effects of irrigation water temperature on emitter discharge and to determine the discharge-pressure variations and manufacturer’s coefficient of variations, an experimental trickle irrigation system was designed and...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید