Plateau formation

Effects of Groundwater Composition and Eh. Radionuclide sorption on geologic solids is dependent on the chemical composition of the groundwater solution and the redox potential (Eh) of the solid-groundwater system. Aquifers at various depths in the Columbia Plateau formation have -been observed to have significant differences in composition. To accurately model radionuclide migration, it is necessary to understand the effects of chemical components and Eh on sorption and solubility of key radionuclides. An additional benefit of this work is to better understand the mechanisms of sorption and desorption of the radionuclides. 

The most recent major phase of oceanic plateau formation was in the Cretaceous when the Ontong Java, Manihiki, Hess Rise, and the Caribbean-Colombian plateaus formed in the... 

The correlation between oceanic plateau formation and marine environmental catastrophes (characterized by mass extinction, oceanic anoxia and black shale deposition) throughout the Mesozoic period suggests a causal link between oceanic plateau formation and environmental crises. 

Kerr A. C. (1998) Oceanic plateau formation a cause of mass extinction and black shale deposition around the Cenoma-nian-Turonian boundary. J. Geol. Soc. London 155, 619-626. 

The self-similar solution of an unsteady rarefaction wave in a gas-vapour mixture with condensation is investigated. If the onset of condensation occurs at the saturation point, the rarefaction wave is divided into two zones, separated by a uniform region. If condensation is delayed until a fixed critical saturation ratio Xc > 1 is reached, a condensation discontinuity of the expansion type is part of the solution. Numerical simulation, using a simple relaxation model, indicates that time has to proceed over more then two decades of characteristic times of condensation before the self-similar solution can be recognized. Experimental results on heterogeneous nucleation and condensation caused by an unsteady rarefaction wave in a mixture of water vapour, nitrogen gas and chromium-K)xide nuclei are presented. The results are fairly well described by the numerical rdaxation model. No plateau formation could be observed. 

The second approach integrates both the catalytic activity and separation efficiency by dissolving the catalyst in the stationary phase or immobilizing the catalyst on to the stationary phase and using columns that are uniformly coated with the catalytically active stationary phase over the complete capillary length (cf. Figure 21.2b). In this case, elution profiles are obtained that are characterized by plateau formation or a more complex convolution of reactant and product. Today, reaction rate constants can be easily determined with the unified equation of chromatography (see below) [37, 38]. 

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