Analyzing groundwater systems in transient state is essential for understanding the response of recharge to changing environments. Radioactive isotopes have long been used track behavior, typically under steady conditions. This study tests limitations using radioactive confined aquifers and conditions sense changes rates over time. Four system parameters determine bounds this approach: isotope ...

Since their introduction in the 1940s, peaceful use of stable isotopes and radioisotopes in the United States has expanded continuously. Today, new isotopes for diagnostic and therapeutic uses are not being developed, critical isotopes for national security are in short supply, and demand for isotopes critical to homeland security exceeds supply. While commercial suppliers, both domestic and fo...

This isotope of curium is radioactive and decays by the emission of an a-particle to form Pu2% which, in turn, is also radioactive. Cm242 has a half life of 150 days and its radioactive daughter, PUCK, has a half life of 50 years. This isotope of plutonium decays by the emission of an a-particle to form U234 which has a half life of 233,000 years. Shortly after the organization of the Atomic En...

1. 65Cu/63Cu stable-isotope ratios have been measured in blood serum after oral administration of the stable isotope 65Cu. The incorporation of the isotope into the plasma protein pool was followed at various times for up to 3 days. The resulting patterns of enrichment in healthy control subjects, in Wilson's disease patients and in heterozygotes for the Wilson's disease gene, were similar in a...

The U-Th radioactive disequilibrium measurements with Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) were applied to a coral reference; JCp-1 distributed by the Geological Survey of Japan to evaluate homogeneity of the standard material. The two times of standard deviations (2SDs) of [U/U]isotope ratio, [ U/U]isotope ratio, U abundance, [ 230Th/ Th]isotope ratio, and T...

I AM very much honoured by your invitation that I should deliver an oration in this valuable and distinguished series that has been established in memory and honour of the life of Robert Campbell, and I wish to speak of the clinical value of radioactive isotopes. In the year in which the Robert Campbell memorial orations were founded, Rutherford had already detected faint scintillations on the ...

We describe the present status of future high-precision measurements of nuclear g-factors utilizing lasermicrowave double and laser-microwave-rf triple resonance methods for online-trapped, laser-cooled radioactive beryllium isotope ions. These methods have applicability to other suitably chosen isotopes and for beryllium show promise in deducing the hyperfine anomaly of Be with a sufficiently ...

A very simple and dirrct radioactive isotope m&hod has been tlwcl~ibed for the quantitative determination of reducing sugars. The method can be adapted to give any degrtte of sensitivity desired. The procedure is of general applicability to the determination of a large class of sugars. The stoichiometry of the reaction makes it a comprehensive procedure which greatly facilitates the analysis of...

of aspergillic acid from isoleucine in replacement cultures (3), there has been no work reported previously on the biogenesis of this antibiotic. In the present work, A. flavus was grown on a medium containing radioactive leucine or isoleucine, and these compounds were found to be incorporated into the aspergillic acid formed. Aspergillic acid was degraded to determine what part of the molecule...