Thesis (M.S. in environmental engineering)--Washington State University, August 2010. / Title from PDF title page (viewed on July 30, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 13-14).

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Made available in DSpace on 2014-10-09T12:38:10Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:50Z (GMT). No. of bitstreams: 1 05651.pdf: 5599024 bytes, checksum: 2673b4e5195ce313cc827fb7eadc9a2c (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

The geometries of the sandstone-hosted calcite concretions of the Jurassic Valtos Sandstone Formation and Bearreraig Sandstone Formation are described and related to the processes operating during concretion growth. As concretionary bodies analogous to those studied form potential permeability barriers within some North Sea petroleum reservoirs; the relationship between the growth processes and permeability barrier formation is examined. The growth times for model spherical concretions are calculated for the complex carbonate-water system. Two growth processes are modelled, solute transport and surface reaction. Growth times for a 1m diameter concretion forming under geologically reasonable conditions are predicted to be 22.3Ma, which reduces to 8.8Ma in porewaters flowing at 1m/year. The depth of formation of the concretions is assessed, through an examination of depth dependent properties of both the host-sediment and the calcite cement, and is found to be less than 500m. Concretion formation preceeded the Paleocene igneous activity which affected the Hebrides. The majority of the concretions examined formed at burial depths which were too great to allow effective contact between the concretions and seawater. The major source of carbonate was the dissolution of aragonitic shell material from within the host sandbody. The nature of the porewaters from which the concretions formed is assessed. The majority were meteoric in origin, though some marine influence is noted. The minor element contents of the cements cannot be used to calculate porewater compositions, as disequilibrium between the porewaters and the cements can be demonstrated. A model is proposed to account for the minor element patterns. Crystal breeding can be demonstrated to have occurred during concretion growth. A hypothesis is presented to explain the petrographic features of a typical Valtos Sandstone Formation concretion.

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An apparatus utilizing a constant pressure flow system was developed for measuring the effect of pressure on the diffusion rates, and therefore diffusion coefficients, of binary gas mixtures passing through porous solids. Hydrogen and nitrogen were employed for testing ceramic porous solids at room temperature, with various pressures from 1 to 14.6 atmospheres absolute. The values obtained for the products of the effective diffusion coefficients and absolute pressures were substantially constant, with a maximum deviation of ±5%. It seemed that the diffusion rate of hydrogen increased with pressure, while that of nitrogen decreased. At atmospheric pressure the ratio of diffusion rates {N(H₂)/N(N₂)} was in good agreement with the theoretical value proposed by Hoogschagen i.e. √M(N₂)/M(H₂). However, the experimental diffusion ratio increased with pressure. This behavior might be due to some degree of forced flow present in the diffusion process, although it was not possible to determine a cause for such a flow. This apparatus is suitable for the study of diffusion rates in the transition region, between Knudsen and ordinary diffusion, by simply changing pressure and hence the mean free path of the gases involved. Forced flow would not be a factor in this region. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

The purpose of this study was (1) to measure the changes in water flux in isolated roots exposed to n-DSA and its mono-methly ester (m-MDSA) using a photometric technique in the absence of an externally applied suction and (2) to measure the flux of Na and K in similarly treated roots using a flame photometric method.

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