نتایج جستجو برای: high density sediments in adjacent mountains

تعداد نتایج: 17301159  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی دکتر علی شریعتی 1389

the current study examined iranian undergraduate efl students’ willingness to communicate with regard to their vocabulary knowledge. in general, participants were somewhat willing to communicate in english. the total mean score of 730 university students’ perception of willing to communicate was 83.53 out of 135. results, regarding four parts of willingness to communicate, revealed that part...

Journal: :محیط شناسی 0
پروین برنجکار کارشناس ارشد مهندسی عمران- مهندسی محیط زیست، دانشگاه علم و صنعت ایران محسن سعیدی دانشیار گروه مهندسی عمران، دانشگاه علم و صنعت ایران

introduction a large volume of sediments are dredged from water bodies such as ports, waterways and wetlands and deposited on land. sediments are typically polluted by contaminants such as heavy metals. metals in sediments are in soluble, carbonate bound, fe-mn oxide, sulfide/organic matter bound and residual fractions. the metal solubility and mobility are mainly controlled by organic matter c...

2013
Shangbin Xiao Rui Li Muhong Chen

Detection of sedimentary cycles is difficult in fine-grained or homogenous sediments but is a prerequisite for the interpretation of depositional environments. Here we use a new autocorrelation analysis to detect cycles in a homogenous sediment core, E602, from the northern shelf of the South China Sea. Autocorrelation coefficients were calculated for different mean grain sizes at various depth...

2012
Marshall W. Bowles Lisa M. Nigro Andreas P. Teske Samantha B. Joye

We measured potential nitrate removal and denitrification rates in hydrothermally altered sediments inhabited by Beggiatoa mats and adjacent brown oil stained sediments from the Guaymas Basin, Gulf of California. Sediments with Beggiatoa maintained slightly higher rates of potential denitrification than did brown sediments at 31.2 ± 12.1 versus 21.9 ± 1.4 µM N day(-1), respectively. In contrast...

Journal: :international journal of environmental research 2010
ch. yu sh. xu m. gang l. zhou g. chen

the concentrations and speciation of mo, together with fe, cu, and zn, in nver river sediments impacted with mo mining activities in western liaoning, northeast china, were investigated withgeochemical method. using the x-ray fluorescence and x-ray diffraction, the characterizations of metals in tailings ponds deposited along the nver river bank were analyzed. analysis and comparison of the con...

1986
Mark W. Luckenbach

Experiments on the entrainment of surface sediments around polychaete tubes at natural and manipulated densities were conducted in a recirculating seawater flume. Intact cores with either 0 or 8 Diopatra cuprea tubes per 0.01 m* plus associated assemblages were collected in the field. Sediments which contained D. cuprea tubes had natural macrofaunal densities > 5 x those of sediments without tu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

abstract ion selective electrodes (ises) are electrochemical sensors that respond selectivity to the activity of ionic species. an ion-selective electrode is an electrochemical device that uses a thin selective membrane or film as the recognition element, and is an electrochemical half-cell equivalent to other half-cells of the zeroth (inert metal in a redox electrolyte). in common methods o...

Journal: :تحقیقات جغرافیایی 0
مریم عسگری گروه جغرافیای طبیعی- دانشگاه تبریز معصومه رجبی گروه جغرافیای طبیعی- دانشگاه تبریز فریبا کرمی

abstract: the aim of this study is analysis of drainage basins neotectonic in the north slope of bozqoosh mountains by geomorphological methods. to attain this aim, it used of field observation, areal photographs and five geomorphic indexes in 20 basins of the north slope of bozqoosh mountains. indexes were calculated by topography maps (1: 50000), geological maps (1: 100000) and areal photogr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه دانشهای بنیادی (مرکز تحقیقات فیزیک نظری و - پژوهشکده فیزیک 1387

چکیده این پایان نامه به بررسی اثر سیم پیچ مغناطیسی و کاوه یِ خوشه گر با بسامد رادیویی بر هاله و بیرونگراییِ باریکه هایِ پیوسته و خوشه ایِ ذرات باردار در شتابدهنده های خطیِ یونی، پروتونی با جریان بالا می پردازد و راه حل هایی برای بهینه نگهداشتن این کمیتها ارایه می دهد. بیرونگرایی یکی از کمیتهای اساسی باریکه هایِ ذرات باردار در شتابدهنده ها است که تاثیر قابل توجهی بر قیمت، هزینه و کاراییِ هر شتابدهند...

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