Results 41 to 50 of about 18,367 (247)

A review of possible mechanisms for mercury migration in diagenesis: Clay to pyrite

Frontiers in Earth Science, 2023
Though sedimentary mercury in marine sediments has been regarded as a geological indicator of volcanic activity based on volcanism activity is the dominant natural source of Hg to the oceans, the influence of diagenesis on mercury cannot be dismissed ...
Huan Xu, Bo Ran, Shugen Liu, Tong Sun, Chao Luo, Yi Li, Yiqing Zhu   +6 more
doaj   +1 more source

The fate of smectite in KOH solutions [PDF]

American Mineralogist, 2006
The aim of the present study was to investigate the detailed evolution of the SAz-1 smectite in 1 M KOH at 80 °C at a solid/liquid ratio of 1/80. AFM observations indicated no change in crystal size or shape. XRD measurements at 40% relative humidity revealed changes in expandability of the smectite. The (001) reflection profile of smectite was modeled
Bauer, A., Lanson, B., Emmerich, K., Ferrage, E., Taubald, H., Schild, D., Velde, B.   +6 more
openaire   +5 more sources

Using small-angle X-ray scattering to investigate the compaction behaviour of a granulated clay [PDF]

, 2015
The compaction behaviour of a commercial granulated clay (magnesium aluminium smectite, gMgSm) was investigated using macroscopic pressure-density measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray microtomography (XμT) and ...
Conway, Barbara R, Sweeney, Francis, Laity, Peter R., Asare-Addo, Kofi, Šupuk, Enes, Conway, Barbara R.; id_orcid   +5 more
core   +1 more source

Local Structures of Se and Br in Cretaceous–Paleogene Boundary Sediments and Concentration Effects of Ferrihydrite Originating From Impact Ejecta

Geological Journal, EarlyView.
Chemical states of Se and Br atoms in the KPg boundary sediments from Stevns Klint were studied using XAFS spectroscopy. The high concentrations of Se4+ could become an index of the degree to which the global environment was soiled with dust and ash derived from impact ejecta or volcanic eruptions.
Kei‐ichiro Murai, Akira Yoshiasa, Ginga Kitahara, Makoto Tokuda, Satoko Ishimaru, Toshihiro Moriga   +5 more
wiley   +1 more source

Clay minerals in the Pliocene–Quaternary sediments of the southern Yangtze coast, China: Sediment sources and palaeoclimate implications

Journal of Palaeogeography, 2014
Clay mineralogy was used as an indicator of the sediment source and prevailing climate and five suites (I–V) were identified throughout the borehole. Smectite was dominant in the bottom suite of the borehole, indicating the sediment was mainly derived ...
Jing Chen, Zhang–Hua Wang, Tao–Yuan Wei, Bao–Cheng Zhao, Zhong–Yuan Chen   +4 more
doaj   +1 more source

ESEM study of illite/smectite freshwater sensitivity in sandstone reservoirs

, 1993
The water sensitivity of authigenic smectite- and illite-rich illite/smectites in sandstone reservoirs has been investigated using an Environmental Scanning Electron Microscope (ESEM). The ESEM enabled the illite/smectites to be directly observed in situ
Mackinnon I.D.R., Baker J.C., Uwins, P. J. R., Mackinnon, Ian D. R., Baker, J. C., Uwins P.J.R.   +5 more
core   +1 more source

Sustainable and miniaturized electrochemical sensors for glyphosate and parabens: integrating biomass‐derived carbons, FDM fabrication, and portable instrumentation

Journal of Chemical Technology &Biotechnology, EarlyView.
Abstract Glyphosate and parabens are chemically distinct emerging contaminants whose field monitoring is constrained by complex matrices and by the cost and infrastructure requirements of conventional laboratory methods. This review evaluates whether biomass‐derived carbon materials, fused deposition modeling (FDM), and portable electrochemical ...
Aline Dassie, William Nieckel, Raphael Menechini Neto, Eduardo Giometti Bertogna, Oldair Donizetti Leite, Humberto Hissaki Takeda, Paulo Roberto de Oliveira, Gideã Taques Tractz, Ana Paula Peron, Luís Avelino Guimarães Dias, Evandro Bona, Osvaldo Valarini Junior   +11 more
wiley   +1 more source

Infrared Spectroscopic Predictions of Soil Properties for Agricultural Monitoring: Statistical and Soil Spectroscopic Considerations

Journal of Plant Nutrition and Soil Science, EarlyView.
ABSTRACT Background: Pseudo‐independent validation (PIV) using regional datasets is common in visible‐to‐near‐infrared (vis–NIR) and mid‐infrared (MIR) spectroscopy studies and produces accurate predictions but is relevant only to regional‐scale monitoring of known sites.
Svenja Tauber, Isabel Greenberg, Bernard Ludwig   +2 more
wiley   +1 more source

Maturation changes of hydrocarbons in solid parts of peloids from Serbian spas - catalytic influence of clay minerals [PDF]

Journal of the Serbian Chemical Society
The study focused on inspecting the composition of n-alkane, sterane and terpane biomarkers in healing mud (peloid) organic matter in the Rusanda, Bujanovac and Vranje spas. It was assumed that the catalytic influence of minerals on changes in biomarkers
Nikolovski Zlatko, Šajnović Aleksandra, Gajica Gordana, Burazer Nikola, Brčeski Ilija, Dabić Predrag, Jovančićević Branimir   +6 more
doaj   +1 more source

Clay-associated organic matter in kaolinitic and smectitic soils [PDF]

, 2002
The primary source of soil organic matter is plant debris of all kinds, such as dead roots, leaves and branches that enter into the soil and are then biologically decomposed at variable rates.
Wattel-Koekkoek, E.J.W.
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