نتایج جستجو برای: hydrometer

تعداد نتایج: 138  

2017
J. M. Howell Mark S. Coyne P. L. Cornelius

Extended survival of fecal bacteria in sediment can obscure the source and extent of fecal contamination in agricultural settings. The variability in fecal coliform/fecal streptococci (FC/FS) ratios with time and discrepancies between observable fecal sources and measured FC/ FS ratios in shallow surface water from agricultural watersheds may be explained by examining FC and FS mortality rates ...

Journal: :محیط شناسی 0
علی قاسمی کارشناس ارشد آبخیزداری دانشکدۀ منابع طبیعی دانشگاه تهران علی سلاجقه استاد آبخیزداری دانشکدۀ منابع طبیعی دانشگاه تهران آرش ملکیان استادیار آبخیزداری دانشکدۀ منابع طبیعی دانشگاه تهران اباذر اسمعلی دانشیار آبخیزداری دانشکدۀ منابع طبیعی دانشگاه محقق اردبیلی

introduction floods are major disasters worldwide that causes serious damage to agriculture, fisheries, housing and infrastructure. they can also disrupt socio-economic activities. as the severity and frequency of flood events have considerably increased, there is a growing global concern about the need to decrease flood related fatalities and associated economic losses. just in 2010, 178 million...

Journal: :زمین شناسی اقتصادی 0
فاطمه هرمزی نژاد فاطمه راست منش علیرضا زراسوندی

introduction soil plays a vital role in human life as the very survival of mankind is tied to the preservation of soil productivity (kabata- pendies and mukherjee, 2007). the purpose of this study is the assessment of heavy metal contamination (zn, mn, pb, fe, ni, cr) of the soil around the khuzestan steel complex. materials and methods for this purpose, 13 surface soil samples (0-10 cm) were t...

Journal: :آب و خاک 0
مجید منتصری سروین زمان زاد قویدل

introduction: a total dissolved solid (tds) is an important indicator for water quality assesment. since the composition of mineral salts and discharge affects the tds of water, it is important to understand the relationships of mineral salts composition with tds. materials and methods: in this study, methods of artificial neural networks with five different training algorithm,levenberg-marquar...

Journal: :آب و خاک 0
الناز رضائی آباجلو کامران زینال زاده

introduction: soil hydraulic conductivity is considered as one of the most important hydraulic properties in water and solutionmovement in porous media. in recent years, variousmodels as pedo-transfer functions, fractal models and scaling technique are used to estimate the soil saturated hydraulic conductivity (ks). fractal models with two subset of two (solid and pore) and three phases (solid,...

Journal: :محیط شناسی 0
فریبا عیسوند کارشناسی ارشد زمین شناسی زیست محیطی، دانشگاه ارومیه بهنام دولتی استادیار گروه علوم خاک، دانشکدۀ کشاورزی، دانشگاه ارومیه حسین پیرخراطی دانشیار گروه زمین شناسی، دانشکدۀ علوم، دانشگاه ارومیه کاظم بدو استاد گروه عمران، دانشکدۀ فنی، دانشگاه ارومیه خلیل فرهادی استاد گروه شیمی، دانشکدۀ علوم، دانشگاه ارومیه،

introduction one concern in the disposal of municipal solid waste (msw) by landfill is the production of leachate. acidic water is capable of dissolving elements from the waste; and, as a result, the leachate can become quite contaminated. one of the heavy metals present in leachate, cadmium poses a great concern in terms of environmental contamination since it is toxic to nearly all living org...

2014
F. WEEKS DoN L. ANDERSON

Values for the strength of sea ice are extremely sparse in the literature, and available values show a wide, unexplained variation. Results of in-place cantilever beam tests presented in this paper show a definite relationship between fl,exural strength and brine content. Values for Young's modulus are also experimentally determined. It is shown that the bearing capacity of a sea-ice sheet is d...

1999
MIRKHALEGH Z. AHMADI Mirkhalegh Z. Ahmadi

A piezometric head method is proposed to estimate the impermeable layer depth used in drain spacing formulae. The method was tested and compared with soil texture changes and the US Bureau of Reclamation (USBR, 1978) criterion of impermeable layer being one with hydraulic conductivity one tenth to one fifth that of the weighted hydraulic conductivity of the upper layers. The proposed method, wh...

Journal: :محیط شناسی 0
امین حسین پور میل آغاردان دانشجوی دکتری مهندسی سیستم های اطلاعات مکانی، دانشکده مهندسی نقشه برداری و اطلاعات مکانی، پردیس دانشکده های فنی دانشگاه تهران رحیم علی عباسپور استادیار گرایش مهندسی سیستم های اطلاعات مکانی، دانشکده مهندسی نقشه برداری و اطلاعات مکانی، پردیس دانشکده های فنی دانشگاه تهران فاطمه شیدایی کارشناس ارشد بخش ترویج و آموزش کشاورزی دانشگاه شیراز

flooding, which is an overflow of water, brings massive biological and economic problems all around the world and disrupts many people’s lives. based on several effective factors in flood occurrence as well as unknown relationships between parameters, researchers have used various methods to forecast flood over the past decade. an investigation of the conducted studies on flood forecasting reve...

2002
B. Asbury

The Western Mining Resource Center (WMRC) at the Colorado School of Mines (CSM) received a grant from the National Institute for Occupational Safety and Health (NIOSH) to perform a study that will help reduce the amount of respirable dust generated from the cutting of coal. The study is based upon laboratory testing and field experience. This information is being used to develop a new cutterhea...

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