Download or read book A Glass Dissolution Model and Mass Transfer from a Waste Glass Cylinder Intersected by a Fissure written by and published by . This book was released on 1991 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Glass Dissolution Model and Mass Transfer from a Waste Glass Cylinder Intersected by a Fissure written by Shaw Jahanshah Zavoshy and published by . This book was released on 1987 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1988 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1987 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Index to American Doctoral Dissertations written by and published by . This book was released on 1989 with total page 1252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radioactive Waste Management written by and published by . This book was released on 1988 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Composition on Glass Dissolution Rates written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Four models have been applied to a data base to relate glass dissolution in distilled water to composition. The data base is used to compare the precisions obtained from the models in fitting actual data. The usefulness of the data base in formulating a model is also demonstrated. Two related models in which the composite or pH-adjusted free energy of hydration of the glass is the correlating parameter are compared with experimental data. In a structural model, the nonbridging oxygen content of the glasses is used to correlate glass dissolution rate to composition. In a model formulated for this report, the cation valence and the oxygen content of the glass are compared with observed dissolution rates. The models were applied to the 28-day normalized silica release at 90/sup 0/C for over 285 glass compositions with surface area to volume ratios of 10 m/sup -1/ (Materials Characterization Center MCC-1 glass durability test using distilled water). These glasses included the nonradioactive analogs of WV205 and SRL-165, as well as SRL-131, PNL 76-68, and a European glass, UK209. Predicted glass dissolution rates show similar fits to the data for all four models. The predictions of the models were also plotted for two subsets of the glasses: waste glasses and Savannah River Laboratory glasses. The model predictions fit the data for these groups much better than they fit the data for the entire set of glasses. 14 refs., 12 figs., 7 tabs.

Download or read book A Kinetic Model for Borosilicate Glass Dissolution Based on the Dissolution Affinity of a Surface Alteration Layer written by William L. Bourcier and published by . This book was released on 1990 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A kinetic model for the dissolution of borosilicate glass, incorporated into the EQ3/6 geochemical modeling code, is used to predict the dissolution rate of a nuclear waste glass.

Download or read book A Kinetic Model for Dissolution of Borosilicate Glass written by William L. Bourcier and published by . This book was released on 1989 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A kinetic model for the dissolution of borosilicate glass, incorporated into the EQ3/6 geochemical modeling code, is used to predict the dissolution rate of a nuclear waste glass. The glass dissolution rate is controlled by the rate of dissolution of an alkali-depleted amorphous surface gel layer. The good agreement between predicted and observed dissolution behavior suggests that the experimentally obtained non-linear glass release rates are not diffusion controlled, as previously believed, but are instead controlled by dissolution affinity. The model predicts that the long-term rate of glass dissolution will depend mainly on ion concentrations in solution, and therefore the secondary phases which precipitate and control ion concentrations.

Download or read book A Critical Evaluation of the Dissolution Mechanisms of High level Waste Glasses in Conditions of Relevance for Geological Disposal GLAMOR written by and published by . This book was released on 2008 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Different theories have been proposed worldwide in the past for interpreting the results from experimental programmes on the dissolution of nuclear waste glasses. The common and important trend is that the dissolution rate of nuclear waste glass decreases with increasing time of exposure to the contacting solution under static conditions. The interpretations are diverging in that the decrease may be attributed to saturation effects in the solution, to protecting effects of the reaction layer formed on the glass surface, or to ion exchange processes between solution and glass. Currently these different interpretations relate to either a thermodynamically (affinity) or with kinetically controlled dissolution behaviour. The first objective of the GLAMOR1 project was to achieve a common understanding amongst the participants on the interpretation of the decrease in dissolution rate of nuclear waste glasses as observed in most experimental programmes and referring to geological disposal conditions. The project started from a selection of existing experimental data and existing analytical models as the basis of its work. A group of acknowledged international experts identified the experimental data to be used in the project and applied the models to the data. The experimental data were produced by various laboratories and under various experimental conditions (i.e. different glass compositions, pure solutions, solutions loaded with solids referring to disposal concepts). The second objective of the project was to better define and quantify the uncertainties associated with the calculations performed in modelling, for instance the uncertainty of the parameters used in the models. This modelling was done so that laboratory data would be properly interpreted and correctly extrapolated beyond the laboratory time scale of several years. As a result of this project we achieved a common view of the different glass dissolution processes, and the different individual views on certain processes were integrated into an overall picture characterised by the following observations: - Glass dissolution is strongly linked to the concentration of dissolved silica and as much as 10 000 times lower long-term dissolution rates relative to the initial dissolution rate can be achieved when Si concentrations are high. - The principal source of high Si concentration is the glass itself. As long as the silica from the glass is not consumed by reaction with near-field materials, high silica concentrations in solution are expected to be achieved in a few months, and correspondingly low glass dissolution rates. Even though there is a general agreement on these observations and on their mathematical treatment in conceptual models, there is still large uncertainty on how to interpret in detail the mechanism by which high silica concentrations slow down the dissolution rates. Two key interpretations were evaluated in detail in the project: (1) affinity-limited dissolution and (2) rate decrease by transport limitation through the reaction layer. We conclude that both affect the rate decrease. By applying the analytical models we realised a better understanding of the role of the different parameters considered in the models and of the impact of the uncertainties of these parameters. We were however unable to quantify the uncertainties associated with the calculations performed in modelling because of the large uncertainties on some of the modelling parameters still existing. The following report provides a summary involving detailed discussions of the two main models and their potential use to explain the long-term behaviour of nuclear waste glasses under conditions relevant for geological disposal conditions.

Download or read book Effects of Glass Surface Area to solution Volume Ratio S V on Glass Dissolution Part One written by and published by . This book was released on 1992 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observed relationship between S/V and leachate pH is discussed in terms of a simple model of the glass dissolution process. Data from leach tests on several nuclear waste glass compositions at different S/V ratios show that the leachate pH increases with time and then stabilizes at a nearly constant value beyond about 28 days. This stabilized pH increases systematically with the S/V ratio of the test. The model developed here reproduces the essential features of the data and suggests that a single parameter describing the intrinsic rate of alkali diffusion and ion exchange from the glass is sufficient to represent the major glass composition dependence. Interestingly, the results are essentially independent of the rate constant for matrix dissolution. This study suggests that the diffusion-ion exchange process is central in determining the solution pH and its dependence on S/V and the glass reaction, at least under static or low-flow-rate test conditions, is driven by alkali release.

Download or read book Dissolution of a Simulated Magnox Waste Glass in Aqueous Solutions at Temperatures Below 100 Degrees C written by Paul K. Abraitis and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Glossary of Prosthodontic Terms written by and published by . This book was released on 1994 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tables of Integral Transforms written by Bateman Manuscript Project and published by . This book was released on 1954 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Twentieth Century Building Materials written by Thomas C. Jester and published by Getty Publications. This book was released on 2014-08-01 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the concluding decades of the twentieth century, the historic preservation community increasingly turned its attention to modern buildings, including bungalows from the 1930s, gas stations and diners from the 1940s, and office buildings and architectural homes from the 1950s. Conservation efforts, however, were often hampered by a lack of technical information about the products used in these structures, and to fill this gap Twentieth-Century Building Materials was developed by the U.S. Department of the Interior’s National Park Service and first published in 1995. Now, this invaluable guide is being reissued—with a new preface by the book’s original editor. With more than 250 illustrations, including a full-color photographic essay, the volume remains an indispensable reference on the history and conservation of modern building materials. Thirty-seven essays written by leading experts offer insights into the history, manufacturing processes, and uses of a wide range of materials, including glass block, aluminum, plywood, linoleum, and gypsum board. Readers will also learn about how these materials perform over time and discover valuable conservation and repair techniques. Bibliographies and sources for further research complete the volume. The book is intended for a wide range of conservation professionals including architects, engineers, conservators, and material scientists engaged in the conservation of modern buildings, as well as scholars in related disciplines.

Download or read book Methods to Study Litter Decomposition written by Manuel A.S. Graça and published by Springer Science & Business Media. This book was released on 2005-04-05 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this book is to provide students and laboratory instructors at universities and professional ecologists with a broad range of established methods to study plant litter decomposition. Detailed protocols for direct use in the field or laboratory are presented in an easy to follow step-by-step format. A short introduction to each protocol reviews the ecological significance and principles of the technique and points to key references.

Download or read book Geology of Massachusetts and Rhode Island written by Benjamin Kendall Emerson and published by Franklin Classics. This book was released on 2018-10-12 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.