Highly fractionated chromium isotopes in Mesoproterozoic-aged shales and atmospheric oxygen [PDF]
There is a long standing debate whether low atmospheric oxygen levels during the Mesoproterozoic Era hindered the evolution of crown-group animals. Here, the authors show with shale-hosted chromium isotopes that sufficient atmospheric oxygen for crown ...
Donald E. Canfield +7 more
doaj +2 more sources
Precise measurement of chromium isotopes by MC-ICPMS. [PDF]
We report novel analytical procedures allowing for the concurrent determination of the stable and mass-independent Cr isotopic composition of silicate materials by multiple collector inductively coupled mass spectrometry (MC-ICPMS).
Schiller M +4 more
europepmc +5 more sources
Method validation and geochemical modelling of chromium speciation in natural waters [PDF]
The study focuses on validating reference methods such as ICP-OES and ICP-MS for detecting ultra-trace levels of chromium in groundwater, where concentrations are typically very low.
Piotr Rusiniak +3 more
doaj +2 more sources
Machine learning models for water safety enhancement [PDF]
Humans encounter both natural and artificial radiation sources, including cosmic rays, primordial radionuclides, and radiation generated by human activities.
Fatemeh Ranjbar +3 more
doaj +2 more sources
Determination of Trace Elements in Nickel-based High-temperature Alloy by High Resolution Plasma Mass Spectrometry [PDF]
The nickel content of nickel-based high-temperature alloy is between 50% and 70%, and the alloy contents of chromium, iron, cobalt, molybdenum, aluminum, titanium and tungsten are within 20%.
HU Xuan1 +6 more
doaj +1 more source
Mechanisms of chromium isotope fractionation and the applications in the environment
Chromium (Cr) is a toxic heavy metal that gives rise to environmental pollution and human risk. Chromium stable isotopes have a wide range of applications in both environmental field and earth science field.
Ying Li +5 more
doaj +1 more source
Mass measurements continue to provide invaluable information for elucidating nuclear structure and scenarios of astrophysical interest. The transition region between the Z=20 and 28 proton shell closures is particularly interesting due to the onset and ...
R. Silwal +26 more
doaj +1 more source
Biogeochemical cycling of chromium and chromium isotopes in the sub-tropical North Atlantic Ocean
Chromium (Cr) is a redox-sensitive element and because Cr isotopes are fractionated by redox and/or biological processes, the Cr isotopic composition of ancient marine sediments may be used to infer changes in past seawater oxygenation or biological ...
Wenhao Wang +6 more
doaj +1 more source
Modeling the marine chromium cycle: new constraints on global-scale processes [PDF]
Chromium (Cr) and its isotopes hold great promise as a tracer of past oxygenation and marine biological activity due to the contrasted chemical properties of its two main oxidation states, Cr(III) and Cr(VI), and the associated isotope fractionation ...
F. Pöppelmeier +8 more
doaj +1 more source
A systematic look at chromium isotopes in modern shells – implications for paleo-environmental reconstructions [PDF]
The chromium isotope system (53Cr ∕ 52Cr, expressed as δ53Cr relative to NIST SRM 979) in marine biogenic and non-biogenic carbonates is currently being evaluated as a proxy for the redox state of the ocean.
R. Frei +4 more
doaj +1 more source

