The Isotopic Constitution of Uranium and the Half-Lives of the Uranium Isotopes. I

1939 ◽  
Vol 55 (2) ◽  
pp. 150-153 ◽  
Author(s):  
Alfred O. Nier
Keyword(s):  
Uranium Isotopes ◽  
Isotopic Constitution

Investigation of an Alleged Nuclear Incident at Greenham Common Airbase Using TI-mass Spectrometric Measurements of Uranium Isotopes

2000 ◽  
Vol 34 (21) ◽  
pp. 4496-4503 ◽  
Author(s):  
Ian W. Croudace ◽  
Phillip E. Warwick ◽  
Rex N. Taylor ◽  
Andrew B. Cundy
Keyword(s):  
Mass Spectrometric ◽  
Uranium Isotopes ◽  
Spectrometric Measurements

scholarly journals New α -Emitting Isotope U214 and Abnormal Enhancement of α -Particle Clustering in Lightest Uranium Isotopes

2021 ◽  
Vol 126 (15) ◽  
Author(s):  
Z. Y. Zhang ◽  
H. B. Yang ◽  
M. H. Huang ◽  
Z. G. Gan ◽  
C. X. Yuan ◽  
...  
Keyword(s):  
Uranium Isotopes ◽  
Particle Clustering

scholarly journals Upper limits on the extent of seafloor anoxia during the PETM from uranium isotopes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew O. Clarkson ◽  
Timothy M. Lenton ◽  
Morten B. Andersen ◽  
Marie-Laure Bagard ◽  
Alexander J. Dickson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Global Scale ◽  
Uranium Isotopes ◽  
Biogeochemical Model ◽  
Emission Scenarios ◽  
Isotope Data ◽  
Upper Limit ◽  
Thermal Maximum ◽  
Upper Limits ◽  
Anoxic Events

AbstractThe Paleocene Eocene Thermal Maximum (PETM) represents a major carbon cycle and climate perturbation that was associated with ocean de-oxygenation, in a qualitatively similar manner to the more extensive Mesozoic Oceanic Anoxic Events. Although indicators of ocean de-oxygenation are common for the PETM, and linked to biotic turnover, the global extent and temporal progression of de-oxygenation is poorly constrained. Here we present carbonate associated uranium isotope data for the PETM. A lack of resolvable perturbation to the U-cycle during the event suggests a limited expansion of seafloor anoxia on a global scale. We use this result, in conjunction with a biogeochemical model, to set an upper limit on the extent of global seafloor de-oxygenation. The model suggests that the new U isotope data, whilst also being consistent with plausible carbon emission scenarios and observations of carbon cycle recovery, permit a maximum ~10-fold expansion of anoxia, covering <2% of seafloor area.

Rapid mineral surface weathering beneath the Greenland Ice Sheet shown by radium and uranium isotopes

2020 ◽  
Vol 547 ◽  
pp. 119663
Author(s):  
Benjamin S. Linhoff ◽  
Mathew A. Charette ◽  
Jemma Wadham
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Uranium Isotopes ◽  
Mineral Surface

scholarly journals The isotopic constitution and atomic weight of lead from different sources

1933 ◽  
Vol 140 (842) ◽  
pp. 535-543 ◽  
Keyword(s):  
Mass Spectra ◽  
Atomic Weight ◽  
Numerical Results ◽  
Mass Spectrograph ◽  
Different Sources ◽  
Complete Account ◽  
Isotopic Constitution

In continuation of the previous communications on the isotopic constitution of the elements determined by photometry of their mass-spectra this paper contains an account of experiments made on lead. Much of the work was done over a year ago and, on account of their great importance in geological problems, some of the numerical results were published. It seemed desirable that the complete account should include, if possible, results of at least one of those abnormal samples reported to have an atomic weight less than 206. These have now been obtained and as the mass-spectrograph is now being partially reconstructed and may not be available for further work of the same kind for some time further delay is unnecessary. Lead is unique among the elements in that it is formed in workable amounts by different processes of radioactive disintegration and so does not have a constant isotopic constitution. The first mass-spectra showing its lines were obtained with the second mass-spectrograph by a discharge in the tetramethyl made from ordinary lead and indicated isotopes 206, 207, 208 roughly in proportions 4, 3, 7 with possibly others. Two years later a specimen of the methyl compound of lead from Norwegian Broggerite was prepared and analysed. The mass-spectra obtained were poor but enabled the three lines 206, 207, 208 to be identified and their relative intensities roughly estimated at 100, 10·7, and 4·5. At the time there was no reason to suppose that the intensities could be affected by the presence of a hydride, so the percentages were worked out at 86·8, 9·3, 3·9. The presence of line 207 was of the greatest interest for, as was pointed out, there was excellent reason for identifying this with the final product of the actinium series, which would settle the atomic weights of the members of the series, that of protactinium being 231. Assuming the ratio 100 : 7 for the number of atoms of uranium lead to actinium lead Lord Rutherford was able to work out the period of actino-uranium, the parent of the actinium series and an isotope of uranium, to be 4·2 x 10 8 years, and deduce other important cosmical conclusions.

scholarly journals Third minima in thorium and uranium isotopes in a self-consistent theory

2013 ◽  
Vol 87 (5) ◽  
Author(s):  
J. D. McDonnell ◽  
W. Nazarewicz ◽  
J. A. Sheikh
Keyword(s):  
Uranium Isotopes ◽  
Consistent Theory ◽  
Self Consistent

DETERMINATION AND DOSE CONTRIBUTION OF URANIUM ISOTOPES AND 210Po ACTIVITY CONCENTRATIONS OF NATURAL SPRING WATERS IN THE PROVINCE OF GRANADA, SPAIN

2018 ◽  
Vol 181 (4) ◽  
pp. 350-359 ◽  
Author(s):  
A Milena-Pérez ◽  
F Piñero-García ◽  
V M Expósito-Suárez ◽  
J Mantero ◽  
J Benavente ◽  
...  
Keyword(s):  
Uranium Isotopes ◽  
Activity Concentrations ◽  
210Po Activity ◽  
Natural Spring
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