نتایج جستجو برای: water entrainment density currents converging channels sedimentaion dams reservoir

تعداد نتایج: 1148344  

Journal: :آب و خاک 0
یوسف رمضانی مهدی قمشی

abstract turbidity current is one of the most important factors that effect the sediments distribution and also their transportation and release from reservoir. in this study, effects of these currents on sedimentation process in sefidroud dam were simulated by tcm model in 30 years period. comparison between the case of turbidity currents that reach to the dam wall and release from the reservo...

1999
William L. Graf

Newly available data indicate that dams fragment the fluvial system of the continental United States and that their impact on river discharge is several times greater than impacts deemed likely as a result of global climate change. The 75,000 dams in the continental United States are capable of storing a volume of water almost equaling one year’s mean runoff, but there is considerable geographi...

Concrete faced rockfill dams (CFRDs) are among the structures that due to their advantages such ease of construction and low execution costs,have attracted more attention nowadays.Due to the fact that during large earthquakes,the hydrodynamic pressure will be large and cannot be ignored,the main purpose of this research is to apply reservoir hydrodynamic pressure of dam reservoir caused by the ...

ژورنال: علوم آب و خاک 1997
موسوی, سیدفرهاد, جلالیان, احمد, صمدی بروجنی, حسین , محمدزاده, احمد ,

One of the most vital problems in the storage and utilization of surface waters for drinking, flood control, hydropower, and agricultural purposes is that of sedimentation in reservoirs and subsequent decline of dam lifetime. The useful lifetime of a dam is defined as the time necessary for approximately 80% of the volume of its initial capacity to be filled by sediments washed in by water. It ...

2015
Gang Chen Josie Geris

A calibrated three-dimensional Environmental Fluid Dynamics Code model was applied to simulate unsteady flow patterns and temperature distributions in the Bankhead river-reservoir system in Alabama, USA. A series of sensitivity model runs were performed under daily repeated large releases (DRLRs) with different durations (2, 4 and 6 h) from Smith Dam Tailrace (SDT) when other model input variab...

Journal: :International Journal of Energy Research 2021

Solar thermal energy and its possible role with regard to self- passive control sedimentation in large reservoirs behind dams is discussed. It known the impact caused by because drastic reduction of natural water flow velocity rivers consequent sediment trapping. Sediment trapping reservoir has not only an environment reducing transported deltas but also limits useful lifetime dam for flood con...

2016
Tess Wright Lisa N. Gillespie Stephen J. O’Leary Karina Needham

Primary auditory neurons rely on neurotrophic factors for development and survival. We previously determined that exposure to brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) alters the activity of hyperpolarization-activated currents (Ih) in this neuronal population. Since potassium channels are sensitive to neurotrophins, and changes in Ih are often accompanied by a shift in ...

Journal: :روش های عددی در مهندسی (استقلال) 0
محسن ایزدی نیا و محمد تقی احمدی m. izadi-nia and m. t. ahmadi

arch dams are generally built in cantilvever monoliths. vertical contraction joints between monoliths control the stresses due to concrete shrinkage and temperature variations. past studies in earthquake safety evaluation of the system often show the tensile fracture and local nonlinear deformation of joints. in this paper, some nonlinear joint element constitutive models are presented to exami...

2015
M. J. OSTAD MIRZA J. MATOS

Numerous stepped spillways were built to date, namely on RCC gravity dams or on valley flanks besides embankment or rockfill dams, while some others are currently under design or construction. In some cases, slope changes may be required on stepped chutes, due to the topography, leading to reduced excavation and related economic benefits. A quite limited number of stepped spillways have been bu...

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