The safe environmental disposal of sulphide bearing materials is fast becoming a major economic factor in determining the profitability of mining operations. Among sulphide minerals, iron sulphides are the most common mining wastes. Surface disposal of pyrite and pyrrhotite mine waste is the major cause of acid mine drainage generation and the consequent environmental damages. / This thesis investigates the use of new technologies and ideas to improve the disposal of mine waste containing pyrite and pyrrhotite. The first recommended improvement is to backfill the materials instead of disposing of them on the surface. There are new approaches and better technologies implemented in the last few years which enable mining operations to backfill total tailings. The new approach is the use of paste backfill technology, which is one of the focuses of this study. The next improvement, that could be economic as well as environmentally beneficial, is to find replacements for the presently used Portland cement (PC) in paste fill matrixes. / The general objectives of this thesis study could be summarised by the following: (1) To study the possible replacement for PC in paste fill containing pyrrhotite. (2) To study the mixture of pyrrhotite containing paste fill and rock fill. (3) To design new binders to replace (totally or partially) the PC used in paste fill containing pyrite.

<p> Langmuir turbulence in the upper ocean is generated by the interaction between the wind-driven shear current and the Stokes drift velocity induced by surface gravity waves. In homogenous (neutrally stratified) shallow water, the largest scales of Langmuir turbulence are characterized by full-depth Langmuir circulation (LC). LC consists of parallel counter-rotating vortices aligned roughly in the direction of the wind. In shallow coastal shelves, LC has been observed engulfing the entire water column, interacting with the boundary layer and serving as an important mechanism for sediment re-suspension. In this research, large-eddy simulations (LES) of Langmuir turbulence with full-depth LC in a wind-driven shear current have revealed deviations from classical log-layer dynamics in the surface and bottom of the water column. For example, mixing due to full-depth LC induces a large wake region eroding the classical bottom (bed) log-law velocity profile. Meanwhile, near the surface, Stokes drift shear serves to intensify small scale eddies leading to enhanced mixing and disruption of the surface velocity log-law. The modified surface and bottom log-layer dynamics induced by Langmuir turbulence and full-depth LC have important implications on Reynolds-averaged Navier-Stokes simulations (RANSS) of the general coastal ocean circulation. Turbulence models in RANSS are typically calibrated under the assumption of log-layer dynamics, which could potentially be invalid during occurrence of Langmuir turbulence and associated full-depth LC. A K-Profile Parameterization (KPP) of the Reynolds shear stress in RANSS is introduced capturing the basic mechanisms by which shallow water Langmuir turbulence and full-depth LC impact the mean flow. Single water column RANS simulations with the new parameterization are presented showing good agreement with LES</p>

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: A, page: 4821. Adviser: Bruce Hannon. Includes bibliographical references (leaves 62-69) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. / Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 3241. Adviser: S. Balachandar. Includes bibliographical references (leaves 188-192) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. / Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 3156. Adviser: Albert J. Valocchi. Includes bibliographical references (leaves 183-206) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7580. Advisers: Charles Werth; John Shapley. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7583. Adviser: Eberhard Morgenroth. Includes bibliographical references (leaves 167-174) Available on microfilm from Pro Quest Information and Learning.

Thèse (Ph.D.)--Université de Sherbrooke (Canada), 2008. / Titre de l'écran-titre (visionné le 12 mars 2009). In ProQuest dissertations and theses. Publié aussi en version papier.

Thesis (Ph.D.)--Syracuse University, 2008. / "Publication number: AAT 3323075."

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 106-108).