نتایج جستجو برای: enrichment factor

تعداد نتایج: 881392  

2002
A. J. A. WINNUBST A. J. BURGGRAAF

A~~act-Semi~uantitative Auger Electron Spectroscopy (AES) on pure monophasic (Z~*)~.~(YO,.~~,,, was used to determine the chemical composition of the grain boundaries. Grain boundary enrichment with Y was observed with an enrichment factor of about 1.5. The difference in activation energy of the ionic conductivity of the grain boundary compared with the bulk can be explained by the Y segregatio...

2013
Yuan-Shih Hu Nancy Long Gustavo Pigino Scott T. Brady Orly Lazarov

Experience of mice in a complex environment enhances neurogenesis and synaptic plasticity in the hippocampus of wild type and transgenic mice harboring familial Alzheimer's disease (FAD)-linked APPswe/PS1ΔE9. In FAD mice, this experience also reduces levels of tau hyperphosphorylation and oligomeric β-amyloid. Although environmental enrichment has significant effects on brain plasticity and neu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی مهندسی 1386

دوره مشترک کارشناسی ارشد بازاریابی و تجارت الکترونیک دانشگاه تربیت مدرس_ دانشگاه تکنولوژی lule? چکیده پایان نامه عوامل موثر بر پذیرش اینترنت بانک توسط مشتریان پیشرفت فناوری اطلاعات و ارتباطات و به طور خاص رشد اینترنت جهت تراکنش های معاملات بازرگانی، تاثیر بسیار عمیقی در صنعت بانکداری داشته است.این در حالی ست که نفوذ بانکداری اینترنتی در کشورهای در حال توسعه بسیار کندتر از نفوذ آن ...

Journal: :محیط شناسی 0
علیرضا واعظی دانشجوی دکتری مهندسی محیط زیست- منابع آب دانشکدۀ تحصیلات تکمیلی محیط زیست دانشگاه تهران عبدالرضا کرباسی دانشیار مهندسی محیط زیست دانشکدۀ تحصیلات تکمیلی محیط زیست دانشگاه تهران مجتبی فخرایی کارشناس ارشد مهندسی محیط زیست- منابع آب دانشکدۀ تحصیلات تکمیلی محیط زیست دانشگاه تهران علیرضا ولی خانی سامانی کارشناس ارشد مهندسی محیطزیست – منابع آب دانشکده تحصیلات تکمیلی محیط زیست دانشگاه تهران مهدی حیدری کارشناس ارشد مهندسی محیط زیست- منابع آب دانشکدۀ تحصیلات تکمیلی محیط زیست دانشگاه تهران

introduction we can obtain useful information about aquatic systems by studying heavy metals in surface sediments. marine sediments can bring out the aquatic contamination. due to heavy metal toxicity, hard biodegradation and easy bioaccumulation in aquatic ecosystems, various indices have been developed such as sediment quality guidelines (sqgs), enrichment factor (ef), pollution load index (i...

ژورنال: بوم شناسی آبزیان 2015
bahador, mehrshad, Dehghani, Mohsen, moradi, abbas, Naji, Abolfazl,

Toxicity of trace metals in the environment, bioaccumulation in aquatic environments and in food chains are of great importance.This study concentrates on the distribution patterns of some heavy metals (Pb, Ni, Zn and Fe) in surface sediments of Shoor River estuary to obtain an overall classification for the origins of the metals in the studied area. In order to determine the degree of Contamin...

Mohammad Elyas Moslempour Sara Shahdadi

20 soil samples collected from the vicinity of the Khash Cement plant, Iran, were analyzed for As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb and Zn using ICP-OES. The results revealed that the metal distribution were in a fluctuating manner considering various distances and direction from the cement facility. However, it was observed that the mean concentration of the soil samples has no special trend wit...

ژورنال: علوم آب و خاک 2019

High concentrations of heavy metals in street dust are considered to be a serious risk to the human health and the environment. In this study, 30 dust samples were collected from the pavements in the main streets of Abadan to determine the level of pollution of heavy metals in the street dust. Heavy metal concentrations were analyzed by inductively coupled spectroscopy (ICP-OES) method. The lev...

M. Yazdi

The Alborz coal basin is located in northern part of Iran. The coal deposits of Shahrood in eastern Alborz, Zirab in central Alborz and Abyek in western Alborz were studied as typical coalfields of the basin. Shemshak Formation which is the main coal-bearing sequence was formed during the Triassic-Jurassic in the basin. It consists of sandstone, siltstone, shale and claystone, which variedly al...

The aim of this study was to determine the extent of metal pollutions and the identification of their major sources in the vicinity of the Sangan iron mine occurring in NE Iran. Soil samples were collected from the vicinity of the mine site and analyzed for heavy metals. In addition, the chemical speciation of these metals was investigated by means of the sequential extraction procedure. The st...

The Zouzan area is located in the SE of Torbat-e- Heydarieh city (NE Iran). This area is located on north part of the Lut block which consists of basaltic andesite, tuff and porphyritic andesite. The purpose of this research is to investigate the enrichment of metal elements in the Zouzan area and provide a metallic geochemical model. For this purpose, 488 stream samples were analyzed using by ...

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