نتایج جستجو برای: bed depth

تعداد نتایج: 208458  

ژورنال: سلامت و محیط زیست 2015
جهانگیری راد, مهسا, معطر, فرامرز, نبی زاده, رامین, نوری, جعفر, یونسیان, مسعود,

Background and Objective: Nitrate is one of the dissolved anions having great health importance in water. Human activities and natural sources are considered as the main roots of nitrate intrusion in to water bodies. The main objective of this paper was to study nitrate removal by packed bed column filled with (PAN)-oxime-nano Fe2O3. Materials and Methods: PAN-oxime-nano Fe2O3 were synthesized ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

today, scouring is one of the important topics in the river and coastal engineering so that the most destruction in the bridges is occurred due to this phenomenon. whereas the bridges are assumed as the most important connecting structures in the communications roads in the country and their importance is doubled while floodwater, thus exact design and maintenance thereof is very crucial. f...

Journal: :JSEA 2010
Seyed Rahman Homayoon Alireza Keshavarzi Reza Gazni

This paper outlines the application of the multi-layer perceptron artificial neural network (ANN), ordinary kriging (OK), and inverse distance weighting (IDW) models in the estimation of local scour depth around bridge piers. As part of this study, bridge piers were installed with bed sills at the bed of an experimental flume. Experimental tests were conducted under different flow conditions an...

ژورنال: مهندسی دریا 2011
اسکافی, مجید , لاری, کامران , مروتی, حسین ,

In this study two breakwater models with different conditions of bed, waves and water level are employed to analyze the toe stability and scour depth. The tests are conducted with regular waves. It is found that the scour depth in front of the rubble-mound breakwater depends on wave height, structure slope, water level and wave period, but the results reveal the effect of wave period toe is mor...

Journal: :international journal of aquatic biology 0
melahat hoghoghi biodiversity department, environment faculty, islamic azad university, science and research branch, tehran, iran. soheil eagderi fisheries department, natural resources faculty, university of tehran, karaj, iran. bahmen shams-esfandabad department of environment, islamic azad university, arak branch, arak, iran.

a fish species prefer a particular habitat where provides its biological requirements, hence, understanding their habitat use and preferences are crucial for their effective management and protection. this study was conducted to assess the habitat use and selection patterns of alburnoides namaki , an endemic fish in jajroud river, namak lake basin, iran. the river was sampled at 18 equally spac...

An experimental study has been conducted on the effectiveness of two types of flow-altering countermeasures placed around a cylindrical pier under clear water condition, which include sacrificial piles and submerged vanes. Their arrangements follow the optimal configurations recommended in the published articles with some modification. The temporal evolution of maximum scour depth and its equil...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2013
tayyeb nazghelichi arezou jafari mohammad hossein kianmehr mortaza aghbashlo

computational fluid dynamics (cfd) is a computational technology that enables researchers to study the dynamics of things that flow. by using cfd, it is possible to build a computational model that represents a system under study. it not only predicts fluid flow behavior, but also the transfer of heat, mass, phase change, chemical reaction, mechanical movement, and stress or deformation of rela...

2005
Tadeusz FLEITUCH Antoni AMIROWICZ Tadeusz Fleituch Antoni Amirowicz

A natural reach of montane stream (length 96 m and 7 m width) was grided into 150 cells (2 × 2 m). Density and biomass of fish (Salmo trutta L. and Cottus poecilopus Heckel) were estimated at each cell, as well as stream depth, current velocity, Froude number, bed granulation and its roughness were measured, and benthic samples from exposed bricks were collected from mid August to early October...

Journal: :آب و خاک 0
رضا بدیع زادگان کاظم اسماعیلی محمود فغفور مغربی مجتبی صانعی

abstract one of the most frequently encountered cases of rapid varied flow is the hydraulic jump. it occurs when a supercritical open channel flow changes into sub critical flow. in the present research, the experimental study of the hydraulic jump on seven sinusoidal corrugated beds with different wave steepness. the wave steepness of sinusoidal corrugated beds is in the range of 0.1667 to 0.7...

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