Spelling suggestions: "subject:"pseudomorphic.""
1 |
Brain Pseudomorphs: Grey Matter, Grey Sediments, and Grey LiteratureO'Connor, Sonia A. 29 June 2009 (has links)
No / This is a volume of papers presented in honour of the archaeologist and palaeopathologist, Don Brothwell. The eclectic mix reflects the diversity of Brothwell's career over four decades, and the influence that he has had upon many aspects of archaeological science. The papers are linked together by the theme of "people" - our evolution, our bodily remains and burial practices, and our behaviour with respect to other animals (particularly as it may be inferred from animal bones). Many of the contributions were presented at an international conference held in 1999 at the University of York to celebrate Don Brothwell's career in the year of retirement.
|
2 |
Effect of Coatings on Mineral Reaction Rates in Acid Mine DrainageHuminicki, Danielle Marie Cecelia 29 September 2006 (has links)
This dissertation includes theoretical and applied components that address the effect of coatings on rates of mineral reactions that occur in acid mine drainage (AMD) environments. The two major projects investigated how diffusion-limited transport of reactants through pore spaces in coatings on mineral grains affects the reaction rate of the underlying mineral. The first project considered the growth of gypsum coatings on the surface of dissolving limestone in anoxic limestone drains (ALD), which reduces the neutralization rate of the dissolving limestone and the subsequent effectiveness of this treatment. The second project investigated the conditions where iron oxyhydroxide coatings form on oxidizing pyrite and the potential strategies to prevent "runaway" AMD by reducing the rate of acid production to the point that the acid can be neutralized by the surrounding rocks.
In both studies, experiments were conducted to measure reaction rates for the underlying minerals, as coatings grew thicker. These experimental data were fit to a diffusion model to estimate diffusion coefficients of reactants through pore spaces in coatings. These models are extrapolated to longer times to predict the behavior of the coated grains under field conditions.
The experimental results indicate that management practices can be improved for ALDs and mine waste piles. For example, supersaturation with respect to gypsum, leading to coating formation, can be avoided by diluting the ALD feed solution or by replacing limestone with dolomite. AMD can be prevented if the rate of alkalinity addition to mine waste piles is faster than acid is produced by pyrite oxidation. The diffusion model developed in this study predicts when iron oxyhydroxide coatings will become thick enough that alkalinity from the surroundings is sufficient to neutralize acid produced by coated pyrite oxidation and additional alkalinity is no longer required. / Ph. D.
|
Page generated in 0.0245 seconds