نتایج جستجو برای: clay mineral

تعداد نتایج: 86526  

Journal: :Physical chemistry chemical physics : PCCP 2011
A Michalkova T L Robinson J Leszczynski

This computational study performed using the density functional theory shows that hydrated and non-hydrated tetrahedral and octahedral kaolinite mineral surfaces in the presence of a cation adsorb the nucleic acid bases thymine and uracil well. Differences in the structure and chemistry of specific clay mineral surfaces led to a variety of DNA bases adsorption mechanisms. The energetically most...

2016
W. R. Hunter T. J. Battin

Sorption of organic molecules to mineral surfaces is an important control upon the aquatic carbon (C) cycle. Organo-mineral interactions are known to regulate the transport and burial of C within inland waters, yet the mechanisms that underlie these processes are poorly constrained. Streamwater contains a complex and dynamic mix of dissolved organic compounds that coexists with a range of organ...

2015
Qiaoyun Huang Huayong Wu Peng Cai Jeremy B. Fein Wenli Chen

Bacterial adhesion onto mineral surfaces and subsequent biofilm formation play key roles in aggregate stability, mineral weathering, and the fate of contaminants in soils. However, the mechanisms of bacteria-mineral interactions are not fully understood. Atomic force microscopy (AFM) was used to determine the adhesion forces between bacteria and goethite in water and to gain insight into the na...

2014
Francis Moyo Roman Tandlich Brendan S. Wilhelmi Stefan Balaz

Renewed focus on the sorption of hydrophobic organic chemicals (HOCs) onto mineral surfaces and soil components is required due to the increased and wider range of organic pollutants being released into the environment. This mini-review examines the possibility of the contribution and mechanism of HOC sorption onto clay mineral sorbents such as kaolinite, and soil organic matter and the possibl...

2014
Sherie C. Harding Barbara P. Nash Erich U. Petersen A. A. Ekdale Christopher D. Bradbury M. Darby Dyar

The Main Glauconite Bed (MGB) is a pelleted greensand located at Stone City Bluff on the south bank of the Brazos River in Burleson County, Texas. It was deposited during the Middle Eocene regional transgression on the Texas Gulf Coastal Plain. Stratigraphically it lies in the upper Stone City Member, Crockett Formation, Claiborne Group. Its mineralogy and geochemistry were examined in detail, ...

Journal: :Journal of agricultural and food chemistry 2002
Yael Golda Mishael Tomas Undabeytia Onn Rabinovitz Baruch Rubin Shlomo Nir

The design and tests of slow-release formulations of sulfometuron (SFM), an anionic sulfonylurea herbicide, are described. The formulations are based on incorporation of the herbicide in octadecyltrimethylammonium (ODTMA) micelles, which adsorb on a clay mineral, montmorillonite. An optimization of herbicide/micelle clay ratios yielded high adsorption of SFM (95%), and at a 1% (w/w) water suspe...

1981
David L. Bish

The detailed mineralogy of the Bullfrog and Tram Members of the Crater Flat Tuff from drill hole USW-G1 has been examined, primarily to characterize fully the amounts and types of clay minerals in the tuffs and the possible effects clay minerals have on rock properties. Results of bulk sample x-ray diffraction analyses agree closely with previous determinations, although slightly higher clay mi...

2004
MAARTEN NACHTEGAAL ANDRÉ M. SCHEIDEGGER RAINER DÄHN DANIEL CHATEIGNER GERHARD FURRER

The sorption capacity of montmorillonite clay minerals for small cations, such as Ni , can be greatly enhanced by modifying the clay mineral with Al(III). In this study, the mechanisms of Ni uptake by Al-modified montmorillonite were studied using extended x-ray absorption fine structure (EXAFS) spectroscopy of powders and polarized EXAFS spectroscopy of self-supporting clay films to delineate ...

Journal: :Jordan Journal of Civil Engineering 2023

Clay-mineral composition is one of the factors that determine physical and engineering behaviours finegrained soils; however, it usually ignored in soil investigations, because determination clay-mineral necessitates using sophisticated instruments which are time-consuming require skilled personnel. Many correlations exist for faster prediction properties from its index properties, but quicker ...

سرچشمه پور, مهدی, فرپور, محمدهادی, نورمندی پور, فیروزه,

Formation of clay minerals is affected by soil forming factors which in turn play an important role in soil management. The aim of the present research was to study genesis, classification, and clay mineralogy of Koshkooiyeh-Anar soils. Four representative pedons were studied for physicochemical and clay mineralogy analyses. Gypsic, salic, and natric were among the diagnostic horizons that have...

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