نتایج جستجو برای: sediment entry

تعداد نتایج: 108618  

Journal: :Journal of environmental sciences 2014
Fengyu Zan Shouliang Huo Jingtian Zhang Li Zhang Beidou Xi Lieyu Zhang

Arsenic (As) fractions in the sediments of seven lakes from East Plain Ecoregion and six lakes from Yungui Plateau Ecoregion, China, were investigated. Results indicated that the total As concentrations in sediment samples of lakes of the East Plain Lake Ecoregion are higher than those of Yungui Plateau Lake Ecoregion. Residual As is the main fraction in sediment samples of lakes from both ecor...

ژورنال: سلامت و محیط زیست 2015
خراسانی, نعمت الله, رضایی, کرامت الله, ریاحی‌بختیاری, علی‌رضا, زمانی, مجتبی,

Background and Objectives: This study was performed to determine and identify the origin, concentration and source of perylene entry and some PAH compounds in surface sediments of Ghalam Goodeh (A), Siyah Kashim (B), and Talab Markazi (C) in Anzali wetland. Materials and methods: We collected 22 samples of sediments (from each region) and 2 samples of soils (from A region) in April of 2012. Sam...

Journal: :محیط زیست طبیعی 0
محمد نعمتی ورنوسفادرانی دانشگاه تربیت مدرس علیرضا ریاحی بختیاری دانشگاه تربیت مدرس zhaoyan gu استاد، انستیتوی زمین شناسی و ژئوفیزیک، آکادمی علوم چین، پکن، چین. guoqiang chu . استادیار، انستیتوی زمین شناسی و ژئوفیزیک، آکادمی علوم چین، پکن، چین

to assess the sources, entry routes and degree of contamination of pah compounds in surface sediments of the southwestern caspian sea coasts (gillan province) total of 129 surface sediment samples from 28 rivers and 5 transect across the gillan province coasts (from astara to lahijan; 10, 20 and 50 m depth) were collected in the spring and summer of 2012. after extraction using soxhlet method, ...

Investigating the features and flow behavior and related component is one of the complex phenomena that make using of software inevitable. The rivers carry sediment content along with water which is created by erosion of riverbed sediment and erosion caused by rainfall or surface runoff flowing over the catchment area. If the action of river dewatering occurs, the entry of sediment into the int...

Journal: :Geomorphology 2014
Brian W Miller Martin W Doyle

Researchers have independently documented the effects of land use on rivers and threats to river management institutions, but the relationship between changes in institutional context and river condition is not well described. This study assesses the connections between resource management institutions, land use, and rivers by integrating social science, geospatial analysis, and geomorphology. ...

2014
Saeed Shanbehzadeh Marzieh Vahid Dastjerdi Akbar Hassanzadeh Toba Kiyanizadeh

This study was carried out to examine heavy metals concentration in water and sediment of upstream and downstream of the entry of the sewage to the Tembi River, Iran. Samples were collected from upstream and downstream and were analyzed for Cd, Cr, Cu, Fe, Pb, Ni, and Zn by atomic absorption spectrophotometer. The results indicated that the average concentration of the metals in water and sedim...

2014
Vivien F. Taylor Deenie Bugge Brian P. Jackson Celia Y. Chen

Mercury is a widespread contaminant in marine food webs, and identifying uptake pathways of mercury species, CH3Hg(+) and Hg(2+), into low trophic level organisms is important to understanding its entry into marine food webs. Enriched stable isotope tracers were used to study benthic vs. pelagic pathways of CH3Hg(+) and Hg(2+) uptake via food to the infaunal estuarine amphipod, Leptocheirus plu...

2017
Eric S Walsh Betty J Kreakie Mark G Cantwell Diane Nacci

Modeling the magnitude and distribution of sediment-bound pollutants in estuaries is often limited by incomplete knowledge of the site and inadequate sample density. To address these modeling limitations, a decision-support tool framework was conceived that predicts sediment contamination from the sub-estuary to broader estuary extent. For this study, a Random Forest (RF) model was implemented ...

2017
Christine N. Shulse Brianne Maillot Craig R. Smith Matthew J. Church

Concentrated seabed deposits of polymetallic nodules, which are rich in economically valuable metals (e.g., copper, nickel, cobalt, manganese), occur over vast areas of the abyssal Pacific Ocean floor. Little is currently known about the diversity of microorganisms inhabiting abyssal habitats. In this study, sediment, nodule, and water column samples were collected from the Clarion-Clipperton Z...

Journal: :Engineering Applications of Computational Fluid Mechanics 2021

Rivers in the north-western region of China have a high sediment content, and construction reservoirs on these rivers must address problem sedimentation that results loss reservoir capacity. In this study, YZD (Yazidang) was considered as typical case, to injection-type water supply Northwest China. The temporal spatial characteristics diversion project were analyzed based available 46-year dat...

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