نتایج جستجو برای: carbonate sands

تعداد نتایج: 28887  

Journal: :Fractal and fractional 2021

In this study, a series of nuclear magnetic resonance (NMR) tests was conducted on calcareous sand, quartz and glass bead with wide range grain sizes, to understand the effect size micro-pore structure fractal characteristics carbonate-based sand silicate-based sand. The pore distribution (PSD) tested materials were obtained from NMR T2 spectra, theory introduced describe properties PSD. Result...

Journal: :Ecological applications : a publication of the Ecological Society of America 2013
K E Kovalenko J J H Ciborowski C Daly D G Dixon A J Farwell A L Foote K R Frederick J M Gardner Costa K Kennedy K Liber M C Roy C A Slama J E G Smits

Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable quantities of extraction process-affected materi...

ژورنال: علوم آب و خاک 2008
صفری سنجانی, علی اکبر, رستمی, کامبیز , محبوبی , علی اکبر , مصدقی, محمد رضا ,

Transport and filtering of pathogenic bacteria through porous media and groundwater resources are important and، therefore the effect of various factors on bacteria transport and filtering has been given a great attention nowadays. In this study، effects of calcium sulfate and carbonate on Psedomonas fluorescens filtration and filtering parameters were investigated in saturated sand columns und...

صفری سنجانی, علی اکبر, رستمی, کامبیز , محبوبی , علی اکبر , مصدقی, محمد رضا ,

Transport and filtering of pathogenic bacteria through porous media and groundwater resources are important and، therefore the effect of various factors on bacteria transport and filtering has been given a great attention nowadays. In this study، effects of calcium sulfate and carbonate on Psedomonas fluorescens filtration and filtering parameters were investigated in saturated sand columns und...

2006
Scott A. Bradford Jirka Simunek Sharon L. Walker

[1] The transport and deposition behavior of pathogenic Escherichia coli O157:H7 was studied under unfavorable electrostatic conditions in saturated quartz sands of various sizes (710, 360, 240, and 150 mm) and at several flow rates. At a given velocity, column effluent breakthrough values for E. coli tended to decrease in magnitude, and concentration curves became more asymmetric with decreasi...

2003
D. M. Hudson S. B. Castor L. J. Garside

Qs Sand Wind-blown sand blankets a number of areas in the western part of the quadrangle. These well-sorted, mediumto fine-grained quartzose sands are commonly deposited on the east to northeast sides of hills but may extend across some flat areas. The sands are uncemented and loose but most are well stabilized by vegetation, locally including trees. The sands are usually white to tan but local...

2017
Stefan Leuko Kaisa Koskinen Laura Sanna Ilenia M D'Angeli Jo De Waele Paolo Marcia Christine Moissl-Eichinger Petra Rettberg

The bacterial diversity in the Su Bentu Cave in Sardinia was investigated by means of 16S rRNA gene-based analysis. This 15 km long cave, carved in Jurassic limestone, hosts a variety of calcite speleothems, and a long succession of subterranean lakes with mixed granite and carbonate sands. The lower level is occasionally flooded by a rising groundwater level, but with only scarce input of orga...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Peter V Hodson

T he extraction and processing of Canada’s massive oil sands in the Athabasca region of northern Alberta have been marked by an ongoing controversy about the nature and extent of associated environmental impacts. Impacts include habitat destruction and fragmentation by surface mining and tailings disposal, depletion of water resources, greenhouse gas and chemical emissions, and the impacts of e...

Journal: :Ground water 2008
Caleb M Conrad Robert W Ritzi David F Dominic

We considered small-scale measurement of permeability in pebbly sands having coarser grains supported in a finer grained matrix (fine packing). Our central question was whether air-based measurements are representative if made with a permeameter tip seal pressed in the sand matrix. We created pebbly sands and variably sorted sands, with systematic variation in aspects of their fine packing. We ...

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