Ridge following methods

The importance of this system for the separation of the trivalent species from each other was recognized in 1953 by D. F. Peppard and his collaborators at the Argonne National Laboratory. This was followed in the same year by the isolation of the "first kilogram" of pure gadolinium by B. Weaver and his co-workers at the Oak Ridge National Laboratory using the same method. Subsequently, the method has been used on both a laboratory and a commercial scale. 

In the following southern Hydrate Ridge Leg 204 case study, Trehu et al. (2004) compared estimates of hydrate fractions by the three methods, relative to the hydrate fractions estimated by resistivity at bit (RAB) logs. All four results consistently indicate that, at depths greater than the crest of the ridge, the average gas hydrate content is generally <2% of the pore space. Such numbers are typical of oceanic hydrates. 

Studies (1, 2, 3, 4) on the separation of americium-curium from lanthanide elements indicate that both cation exchange chromatography (8, 9) and the Talspeak solvent extraction process (U), 11) are promising methods. Only the most recent work at Oak Ridge National Laboratory is reported in this paper. Potential chemical processes for americium-curium removal and evaluations of their feasibility have been reported previously (U 2, 3, 4). The most recent experimental work carried out includes the following ... 

The procedures outlined below are not intended to be a comprehensive list or review of solvent extraction analytical separations for radionuclides but, rather, to provide a condensed guide to some recently developed methods (primarily at Oak Ridge National Laboratory, Oak Ridge, Tennessee) that illustrate the advantages offered by this approach to radiometric analyses. Selected procedures follow. 

As mentioned earlier, there are several analytical methods that have been developed for the analysis of uranium in urine. Some of the older methods required separation and preconcentration of the uranium from the urine sample, but modern methods, based mainly on ICPMS, allow direct determination of the uranium in raw urine or after simple dilution. In the following section, some of the older analytical methods for determining uranium in urine will be described. This section is based in part on a review that was carried out at Oak Ridge National Laboratory (Bogard 1996). 

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