Results 31 to 40 of about 734 (136)

Active growth of non-hydrothermal subaqueous and subaerial barite (BaSO4) speleothems in Lechuguilla Cave (New Mexico, USA)

International Journal of Speleology, 2020
Barite (BaSO4) speleothems have been reported from caves around the globe and interpreted to have chiefly formed in phreatic, hypogene, hydrothermal settings.
Max Wisshak, Hazel A. Barton, Katey E. Bender, Harvey R. DuChene   +3 more
doaj   +1 more source

Effects of Temperature and Particle Size Distribution on Barite Reduction by Carbon monoxide Gas [PDF]

Journal of Particle Science and Technology, 2016
In this research, a mineral barite powder was reduced by carbon monoxide gas and the effects of reduction time and temperature was investigated as well as barite particle size.
Saeed Vakilpour, Ahmad Ghaderi Hamidi
doaj   +1 more source

Monte carlo assessment of advanced shielding materials for space‐efficient radiotherapy vault design

Journal of Applied Clinical Medical Physics, Volume 27, Issue 8, August 2026.
Abstract Background Conventional radiotherapy vault shielding typically employs 2 to 3 meters of ordinary concrete, consistent with NCRP Report 151 reference data. While NCRP 151 specifies dose‐based design goals rather than mandating particular materials, the practical default of concrete results in vault footprints of 150 to 200 m2 per linac, which ...
Beechui Koo, Richard Xu, Morgan Glennie, Jungwook Shin, Karl Farrey, Siyong Kim, James J. Sohn   +6 more
wiley   +1 more source

Control de vocabulario: orígenes, evolución y proyección

Ciência da Informação, 2015
Las cuestiones relacionadas con el control de vocabulario están fuertemente asentadas en la literatura de la Organización del Conocimiento desde los orígenes mismos de este campo temático.
Mario Barité
doaj  

Barite mineralization in Kalana speleothems, Central Estonia: Sr, S and O isotope characterization [PDF]

Estonian Journal of Earth Sciences, 2017
Barite mineralization in association with calcitic speleothem precipitates in cave structures in Silurian Aeronian carbonate rocks in Kalana quarry, Central Estonia, was studied. Barite mineralization in Kalana occurs in two generations – euhedral bladed-
Mikk Gaškov, Holar Sepp, Päärn Paiste, Kalle Kirsimäe, Tõnu Pani   +4 more
doaj   +1 more source

Carbonate‐Associated Sulfate Does Not Record Superheavy δ34S in Deep Scandinavian Bedrock Fractures: Implications for Pyrite Formation in the Deep Biosphere

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract In deep bedrock fractures of the Fennoscandian shield, pyrite with “superheavy” δ34S values of up to 147‰ exists together with calcite. The extreme variability and 34S‐enrichment in pyrite indicate that microbial sulfate reduction (MSR) evolved to almost complete sulfate exhaustion in closed‐system microenvironments.
V. Fichtner, F. Genske, E. Kooijman, H. Drake   +3 more
wiley   +1 more source

Geochemical characteristics of mercurian tetrahedrite, barite and fluorite from the Duboki Vagan, Glumac and Dubrave-Dugi Dol barite deposits, south of Kreševo, Mid-Bosnian Schist Mts.

Geologia Croatica, 2011
The geochemical characteristics of tetrahedrite and barite of the Duboki Vagan barite deposit near the town of Kreševo in the MBSM (Mid-Bosnian Schist Mountains) have been determinated and correlated with the results of previously studied barite ...
Ivan B. Jurković, Vesnica Garašić, Ivan Jurković   +2 more
doaj   +1 more source

Structurally‐Controlled Permeability Evolution and Mineralization in Geothermal Caprocks: The Fenice Capanne Mining District (Southern Tuscany, Italy)

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract The Neogene mineralized region of the Colline Metallifere in southern Tuscany (Italy) provides a natural laboratory to investigate feedback between fluid–rock interaction, structurally controlled fluid flow, and hydrothermal ore mineralization.
Barbara Marchesini, Federico Rossetti, Ahmad Rabiee, Andrea Billi, Andrea Cavallo, Davide Novella, Vincenzo Moretto, Antonio Caracausi, Fabio Trippetta, Luca Aldega, Luigi Dallai, Giovanni Ruggieri, Eugenio Carminati   +12 more
wiley   +1 more source

Early–Late Carboniferous Tectonic Evolution of the Northern North China Craton (NE China): Constraints From Zircon Ages, Geochemistry, and Crustal Thickness Modeling

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 8, August 2026.
Abstract The tectonic evolution of the northern margin of the North China Craton (NCC) remains controversial. In this study, we obtained zircon U–Pb ages, geochemical data, and Sr–Nd isotopic data for volcanic rocks, and detrital zircon ages for sedimentary rocks from the Yufutun, Tongqigou, and Benxi formations in central‐southern Jilin Province, NE ...
Yunfei Chang, Qingxiang Du, Huachun Gan, Xiaoli Shen, Zuozhen Han, Xiaoxue Hou, Huicong Zhang   +6 more
wiley   +1 more source

A Kolmogorov–Arnold Surrogate Model for Chemical Equilibria: Application to Solid Solutions

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 4, August 2026.
Abstract The computational cost of geochemical solvers is a challenging matter. For reactive transport simulations, where chemical calculations are performed up to billions of times, it is crucial to reduce the total computational time. Existing publications have explored various machine learning approaches to determine the most effective data‐driven ...
Leonardo Boledi, Dirk Bosbach, Jenna Poonoosamy   +2 more
wiley   +1 more source