Results 81 to 90 of about 20,135 (183)

Zoning and contamination rate of magnesium and heavy metals of iron, zinc and copper in the north and northwest aquifer of Khoy (Zourabad) based on GIS and determining the contaminated source

Journal of Economic Geology, 2015
Introduction Heavy metals are the most toxic pollutants in aquatic ecosystems. This contamination can result from the release of heavy metal elements during alteration and weathering of ultramafic and mafic rocks (ophiolite zones).
Fariborz Khodadadi, Abdolnaser Fazlnia, Hossein Pirkharrati   +2 more
doaj  

Response of Remote Tropical West Pacific Islands to Climate Variability: A Multiproxy Record From T‐Lake, Palau, Spanning the Early Holocene to Present

Archaeometry, EarlyView.
ABSTRACT Lake sediments are natural archives of past environmental dynamics and how these systems have responded to past climate variability. Sediment geochemistry, governed by local geology and climate processes, is unique to each lake‐catchment and geochemical proxies must be validated for each study site.
Jalene Nalbant, Larissa Schneider, Jessica L. Blois, Matthew Wolhowe, Julian P. Sachs, Simon G. Haberle, Geoffrey Clark   +6 more
wiley   +1 more source

Metal sources for the Katanga Copperbelt deposits (DRC) insights from Sr and Nd isotope ratios [PDF]

, 2014
The ore deposits of the Central African Copperbelt formed during a multiphase mineralisation process. The basement underlying the Neoproterozoic Katanga Supergroup that hosts the ore, demonstrates the largest potential as metal source.
El Desouky, Hamdy A, Elburg, Marlina A, Muchez, Philippe, Van Wilderode, Jorik, Vanhaecke, Frank   +4 more
core   +1 more source

Impurity Diffusion and Isotope Effect of Cobalt in α-Iron

Materials Transactions, JIM, 1993
Impurity diffusion and the isotope effect of cobalt in α-iron have been studied by a serial radio-frequency sputter-microsectioning method with radioactive tracers 57 Co and 60 Co in the temperature range 859 to 1173 K. of the magnetic spin ordering on the diffusion of cobalt than that on the self-diffusion in α-iron has been observed.
Yoshiaki Iijima, Kazuhiro Kimura, Chan-Gyu Lee, Ken-ichi Hirano   +3 more
openaire   +2 more sources

Droughts and human impact in the ancient Uaymil region of the Maya lowlands inferred from a 2800‐year sedimentary archive at Lake Kaná, Mexico

Boreas, EarlyView.
The relationship between the climate and societal transformation in Maya lowlands has long been debated, particularly the role of drought in shaping the civilization trajectory during the Classic Period. A high‐resolution, multi‐proxy, geochemical record from Lake Kaná, located in the underexplored Uaymil region of the Yucatán Peninsula in Mexico ...
Haydar B. Martinez‐Dyrzo, Priyadarsi D. Roy, Benjamin Gwinneth, Irma G. Vargas‐Martinez, Alejandro A. Aragon‐Moreno, Roger Medina‐Gonzales   +5 more
wiley   +1 more source

Abundance Tomography of Type Iax SN 2011ay with TARDIS

, 2017
We present a detailed spectral analysis of Type Iax SN 2011ay. Our spectra cover epochs between -3 and +19 days with respect to the maximum light in B-band. This time range allows us to employ a so-called abundance tomography technique.
Barna, Barnabas, Kerzendorf, Wolfgang E., Kromer, Markus, Marion, G. H., Silverman, Jeffrey M., Szalai, Tamas, Vinko, Jozsef, Wheeler, J. Craig   +7 more
core   +1 more source

In situ single‐spot Rb/Sr cosmochronology of roedderite in the Ribbeck aubrite (asteroid 2024 BX1)

Meteoritics &Planetary Science, EarlyView.
Abstract The mineralogy and textures of several fragments from the Ribbeck aubrite were analyzed using a combination of scanning electron microscopy, electron microprobe analysis, μRaman spectroscopy, and laser ablation inductively coupled reaction cell mass spectrometry (LA‐ICP‐MS/MS).
Christopher J. Barnes, Aleksander Błasiak, Helge Vinje Birgerheim, Matthias Konrad‐Schmolke, Delia Rösel, Jarosław Majka, Thomas Zack   +6 more
wiley   +1 more source

The effect of terrestrial weathering on the mineralogy and petrologic (sub)types of CM chondrites explored by kinetic modeling and laboratory experiments

Meteoritics &Planetary Science, EarlyView.
Abstract Terrestrial weathering alters the chemical and isotopic composition, and mineralogy, of meteorites; its effects on ordinary chondrites are well‐studied, but relatively little is known about the susceptibility of carbonaceous chondrites. We combined laboratory experiments, whereby Chwichiya 002 (C3‐ung find), Murchison (CM2 fall) and Kolang ...
Robin L. Haller, Martin R. Lee, Mark E. Hodson   +2 more
wiley   +1 more source

Covalent Organic Framework–Carbon Nanotube Core–Shell Nanohybrids for Enhanced Catalytic Site Utilization of Molecular Catalysts in CO2 Electroreduction

Angewandte Chemie, Volume 138, Issue 18, 27 April 2026.
Covalent organic framework–carbon nanotube (COF–CNT) core–shell nanohybrids are developed as an efficient platform to enhance the site utilization of molecular catalysts for electrochemical CO2 reduction. The well‐defined nanostructure promotes catalytic site accessibility, achieving CO turnover frequencies among the highest reported to date.
Liang Yao, Andrés Rodríguez‐Camargo, Roman Guntermann, Fabian Heck, Samuel Van Gele, Hugo Vignolo‐González, Viola Duppel, Thomas Bein, Bettina V. Lotsch   +8 more
wiley   +2 more sources

216 Jewish Hospital of St. Louis [PDF]

, 1955
https://digitalcommons.wustl.edu/bjc_216/1025/thumbnail ...

core   +1 more source