Results 31 to 40 of about 27,362 (303)

Isotope fractionation in silicate melts [PDF]

Nature, 2012
Arising from G. Dominguez, G. Wilkins & M. H.
Daniel J, Lacks, James A, Van Orman, Charles E, Lesher   +2 more
openaire   +2 more sources

Microbiological Fractionation of Sulphur Isotopes [PDF]

Journal of General Microbiology, 1964
SUMMARY: A fractionation of sulphur isotopes was found in all metabolic processes investigated except those in which elemental sulphur was the starting substrate for growth of Thiobacillus concretivorus and Chromatium sp. and for reduction by Saccharomyces cerevisiae. Except for polythionates formed during sulphide oxidation by T.
I R, KAPLAN, S C, RITTENBERG
openaire   +2 more sources

Silicon Isotope Geochemistry: Fractionation Linked to Silicon Complexations and Its Geological Applications

Molecules, 2019
The fundamental advances in silicon isotope geochemistry have been systematically demonstrated in this work. Firstly, the continuous modifications in analytical approaches and the silicon isotope variations in major reservoirs and geological processes ...
Wei Wang, Hai-Zhen Wei, Shao-Yong Jiang, Xi Liu, Fang Lei, Yi-Bo Lin, Yao Zhao   +6 more
doaj   +1 more source

Evidence for the mechanisms of zinc uptake by rice using isotope fractionation [PDF]

, 2010
In an earlier study, we found that rice (Oryza sativa) grown in nutrient solution well-supplied with Zn preferentially took up light 64Zn over 66Zn, probably as a result of kinetic fractionation in membrane transport processes.
Wissuwa, M., Kirk, G. J. D., Weiss, D. J., Zhao, F-J., Mason, T. F. D., Frei, M., Arnold, T.   +6 more
core   +1 more source

Nitrogen Isotope Fractionation During Archaeal Ammonia Oxidation: Coupled Estimates From Measurements of Residual Ammonium and Accumulated Nitrite

Frontiers in Microbiology, 2020
The naturally occurring nitrogen (N) isotopes, 15N and 14N, exhibit different reaction rates during many microbial N transformation processes, which results in N isotope fractionation. Such isotope effects are critical parameters for interpreting natural
Maria Mooshammer, Ricardo J. E. Alves, Barbara Bayer, Michael Melcher, Michaela Stieglmeier, Lara Jochum, Simon K.-M. R. Rittmann, Margarete Watzka, Christa Schleper, Gerhard J. Herndl, Gerhard J. Herndl, Wolfgang Wanek   +11 more
doaj   +1 more source

Constraints on barium isotope fractionation during aragonite precipitation by corals [PDF]

, 2015
We present a barium (Ba) isotope fractionation study of marine biogenic carbonates (aragonitic corals). The major aim is to provide first constraints on the Ba isotope fractionation between modern surface sea water and coral skele- ton.
Van Zuilen, Kirsten; id_orcid, van Zuilen, Kirsten, Reynaud, Stéphanie, Pretet, Chloé, Böttcher, Michael E., Samankassou, Elias, Nagler, Thomas F., Nägler, Thomas   +7 more
core   +1 more source

Molybdenum isotope fractionation at upper-crustal magmatic-hydrothermal conditions [PDF]

, 2021
Molybdenum isotopes are an established proxy for paleoredox conditions in low-temperature surface systems. However, the mechanisms behind demonstrated Mo isotope fractionation during igneous and hydrothermal processes at elevated temperatures are still ...
Pettke, Thomas, Wille, Martin, Kaufmann, Anne K. C., Kaufmann, Anne K.C.   +3 more
core   +1 more source

Effect of Metabolic Constraints on the Observable Isotope Fractionation Associated with Aerobic Biodegradation of Hexachlorocyclohexanes

, 2019
Biodegradation of the highly persistent hexachlorocyclohexanes is difficult to assess in contaminated soils and sediments because this process occurs only slowly over timescales of years to decades.
Hans-Peter E., Kohler, Iris E., Schilling, Thomas, Hofstetter   +2 more
core   +1 more source

Influences of Acid Fractionation on Determination of Carbon and Oxygen Isotope Analysis of Carbonates Using GasBench-IRMS

Zhipu Xuebao
Phosphoric acid is commonly used to react with carbonates to generate carbon dioxide for determining the carbon and oxygen isotopes of carbonates by using online reaction device, for example, GasBench coupled to an isotope ratio mass spectrometer (IRMS).
Nan WANG, Yan-yan ZHAO, You-rong TIAN
doaj   +1 more source

Controls Over Oxygen Isotope Fractionation in the Waters and Bivalves (Arthritica helmsi) of an Estuarine Lagoon System

Geochemistry, Geophysics, Geosystems, 2021
Oxygen isotope ratios in bivalve shells have long been used as a proxy for environmental change, reflecting both temperature and the oxygen isotope composition of host water. In estuarine systems, the oxygen isotope composition of water is complicated by
B. K. Chamberlayne, J. J. Tyler, B. M. Gillanders   +2 more
doaj   +1 more source