No description available.

No description available.

No description available.

Attenuation of uranium (U) and rare earth elements (REEs) has been observed in stream and wetland sediments, but the geochemical and mineralogical processes involved in sequestering these elements in natural systems are not well understood. The decommissioned Bicroft Uranium Mine near Bancroft, ON uses a modified stream and wetland system to reduce the concentrations of U and other metals in tailings pond effluent to levels below the Provincial Water Quality Objectives. The Bicroft Mine was operated from 1957 to 1963, and processed low-grade (~0.17 wt% U3O8), disseminated U hosted by pegmatite dykes in amphibolite gneiss, forming 2,284,421 tonnes of tailings, deposited into two tailings impoundments. The Bicroft site has since operated as a passively attenuating stream and wetland remediation system for 55 years, demonstrating the potential longevity and viability for long-term sequestration of U and REEs through natural attenuation. To identify U and REE hosts and their stability in the natural environment, colloids, tailings, stream and wetland sediments were analyzed using various methods, including tangential flow filtration (TFF), ICP-ES/MS, scanning electron microscopy, and synchrotron techniques (bulk and µXANES, µXRF, and µXRD). The results show that Fe- and Mn-oxyhydroxides, goethite, and birnessite are the main mineral hosts for U and REEs in both the colloids and sediments. In addition, detrital grains of U- and REE-bearing minerals were found >200 m downstream in colloids and wetland sediments, showing the potential for long range transport of colloids and particulates in the stream system. Seasonal influences on the stability of trace metals in sediments were observed, and may demonstrate the limitations of passively attenuating remediation systems as a viable method for attenuation. Changes in the redox state of the stream system were observed to influence the attenuation of U and REEs, however, changes in the redox state with depth in the wetland sediments were not observed, and showed no direct influence on the attenuation of U and REEs. The results of this study will help to develop better monitoring strategies for U tailings sites and should reduce the impacts of future U mining operations. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2013-05-06 07:44:03.327

This paper is to present a study of ultrastructured elements of the microcosm as a stimulus for painting.

by Mok Chuen Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1979. / Includes bibliographies.

Queenie Wai Yan Ip. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 91-94). / Abstracts in English and Chinese. / Acknowledgements --- p.ii / Abstract --- p.iii / 摘要 --- p.v / List of Abbreviations --- p.xii / List of Compounds Synthesized --- p.xiii / Chapter CHAPTER 1 --- Syntheses and Characterizations of Pyrazyl-Linked Bis(l-Aza-Allyl) Alkali-Metal Complexes / Chapter 1.1. --- Introduction --- p.1 / Chapter 1.1.1. --- A General Review of 1-Aza-Allyl Ligands --- p.1 / Chapter 1.1.2. --- A General Review of Group 1 Alkali-Metal Complexes Containing Bis(l-Aza-Allyl) Ligands --- p.6 / Chapter 1.2. --- Objective --- p.9 / Chapter 1.3. --- Results and Discussion --- p.11 / Chapter 1.3.1. --- Preparation and Characterization of Pyrazyl-Linked Bis(l-Aza-Allyl) Di-Lithium Complex --- p.11 / Chapter 1.3.1.1. --- "A Modified Synthesis of Pyrazyl-Linked Bis(l-Aza-Allyl) Di-Lithium Complex [Li2{{N(SiMe3)C(But)C(H)}2C4H2N2-2,3}(THF)2]2 (1)" --- p.11 / Chapter 1.3.1.2. --- Physical and Spectroscopic Properties of Complex 1 --- p.11 / Chapter 1.3.1.3. --- Molecular Structure of Complex 1 --- p.12 / Chapter 1.3.2. --- Preparation and Characterization of Pyrazyl-Linked Bis(l-Aza-Allyl) Di-Sodium and Di-Potassium Complexes --- p.15 / Chapter 1.3.2.1. --- "Preparation of Pyrazyl-Linked Bis( 1 -Aza-Allyl) Di-Sodium complex [Na2{{N(SiMe3)C(But)C(H)}2C4H2N2-2,3}(THF)2]2 (2) and Di-Potassium Complex [K2{{N(SiMe3)C(But)C(H)}2C4H2N2-2,3}- (THF)3]2 (3)" --- p.15 / Chapter 1.3.2.2. --- Physical and Spectroscopic Properties of Complexes 2 and 3 --- p.15 / Chapter 1.3.2.3. --- Molecular Structures of Complexes 2 and 3 --- p.16 / Chapter 1.4 --- Experimental Section --- p.23 / Chapter 1.5 --- References --- p.25 / Chapter CHAPTER 2 --- Syntheses and Characterizations of Pyrazyl-Linked Bis(l-Aza-Allyl) Group 2 and 12 Metal Complexes / Chapter 2.1 --- Introduction --- p.29 / Chapter 2.1.1. --- A General Review of Group 2 Metal Complexes containing Bis(l-Aza-Allyl) Ligands --- p.29 / Chapter 2.1.2. --- A General Review of Group 12 Metal Complexes containing Bis(l-Aza-Allyl) Ligands --- p.32 / Chapter 2.2 --- Results and Discussion --- p.34 / Chapter 2.2.1. --- Preparation and Characterization of Pyrazyl-Linked Bis(l-Aza-Allyl) Di-Magnesium Complex --- p.34 / Chapter 2.2.1.1. --- "Preparation of Pyrazyl-Linked Bis(l-Aza-Allyl) Di-Magnesium Complex [Mg2{{N(SiMe3)C(But)C(H)}2C4H2N2-2,3}Br2(THF)4] (4).……" --- p.34 / Chapter 2.2.1.2. --- Physical and Spectroscopic Properties of Complex 4 --- p.34 / Chapter 2.2.1.3. --- Molecular Structure of Complex 4 --- p.35 / Chapter 2.2.2. --- Preparation and Characterization of Pyrazyl-Linked Bis(l-Aza-Allyl) Lithium Zincate Complex --- p.38 / Chapter 2.2.2.1. --- "Preparation of Pyrazyl-Linked Bis(l-Aza-Allyl) Lithium Zincate Complex [Zn2{{N(SiMe3)C(But)C(H)}2C4H2N2-2,3}Cl2(u-Cl)2Li2(THF)6] (5)" --- p.38 / Chapter 2.2.2.2. --- Physical and Spectroscopic Properties of Complex 5 --- p.39 / Chapter 2.2.2.3. --- Molecular Structure of Complex 5 --- p.39 / Chapter 2.2.3. --- Preparation and Characterization of Unexpected Cyclization Compound --- p.42 / Chapter 2.2.3.1. --- "Preparation of Unexpected Cyclization Compound [{Me2Si{NC(But)C(H)}}2C4H2N2-2,3] (6)" --- p.42 / Chapter 2.2.3.2. --- Physical and Spectroscopic Properties of Complex 6 --- p.43 / Chapter 2.2.3.3. --- Molecular Structure of Complex 6 --- p.44 / Chapter 2.2.4. --- Attempted Synthesis of Analogous Mercury Complex --- p.45 / Chapter 2.2.5. --- Comparison on Structures and Reactivities of Compounds 4-6 --- p.46 / Chapter 2.3. --- Experimental Section --- p.48 / Chapter 2.4. --- References --- p.50 / Chapter CHAPTER 3 --- Syntheses and Characterizations of Bis(Phosphoranoimido) Magnesium and Group 14 Metal Complexes / Chapter 3.1 --- Introduction --- p.52 / Chapter 3.1.1. --- A General Review of Functionalized Phosphoranoimine Ligands --- p.52 / Chapter 3.1.2. --- A General Review of Group 14 Metal Complexes Containing Bis(Phosphoranoimines) Ligands --- p.59 / Chapter 3.2. --- Objective --- p.61 / Chapter 3.3. --- Results and Discussion --- p.64 / Chapter 3.3.1. --- Preparation and Characterization of Bis(Phosphoranoimido) Magnesium Complexes --- p.64 / Chapter 3.3.1.1. --- "Preparation and Characterization of Bis(Phosphoranoimido) Magnesium Complexes [Mg{(Me3SiN=PR2CH)2C5H3N-2,6}THF] (R = Pri, 9; R = Ph, 10)" --- p.64 / Chapter 3.3.1.2. --- Physical and Spectroscopic Properties of Complexes 9 and 10 --- p.64 / Chapter 3.3.1.3. --- Molecular Structures of Complexes 9 and 10 --- p.65 / Chapter 3.3.2. --- Preparation and Characterization of Bis(Phosphoranoimido) Tin(II) and Lead(II) Complexes --- p.70 / Chapter 3.3.2.1. --- "Preparations and Characterizations of 1,3-Distannacyclobutane with Chlorotin(II) Alkyl Complex [{2-{Sn{C(Pri2P=NSiMe3)}}-6- {Sn{CH(Pri2p=NSiMe3)}Cl}}C5H3N]2 (11) and 1,3-Diplumbacyclobutane with bis(trimethylsilyI)amido Lead(II) Alkyl Complex [{2-{Pb{C(Pri2P=NSiMe3)}}-6-{Pb{CH(Pri2P=NSiMe3)}N(SiMe3)2}}- C5H3N]2 (12)" --- p.70 / Chapter 3.3.2.2. --- Physical and Spectroscopic Properties of Complexes 11 and 12 --- p.73 / Chapter 3.3.2.3. --- Molecular Structures of Complexes 11 and 12 --- p.74 / Chapter 3.3.3. --- Preparation and Characterization of Bis(Phosphoranoimido) Germanium(II) Enamido and Alkyl Complex --- p.79 / Chapter 3.3.3.1. --- Preparation and Characterization of Bis(Phosphoranoimido) Germanium(II) Enamido and Alkyl Complex [{2-CH(Pri2P=NSiMe3)-6-CH(Pri2P=NSiMe3)}C5H3NGe{2-{C(Pri2P=NSi Me3)Ge} -6-CH2(Pri2P=NSiMe3)} C5H3N] (13) --- p.79 / Chapter 3.3.3.2. --- Physical and Spectroscopic Properties of Complex 13 --- p.81 / Chapter 3.3.3.3. --- Molecular Structure of Complex 13 --- p.81 / Chapter 3.3.4. --- Comparison on Structures and Reactivities of Compounds 11-13 --- p.85 / Chapter 3.4. --- Experimental Section --- p.87 / Chapter 3.5. --- References --- p.91 / APPENDIX I / Chapter A --- General Experimental Procedures and Physical Measurement --- p.95 / Chapter B --- X-Ray Crystallography --- p.96 / APPENDIX II / Tables of Crystallographic Data and Refinement Parameters --- p.98

Liu Ho Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract (Chinese) --- p.ii / Abstract --- p.iii / Acknowledgement --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview and history --- p.1 / Chapter 1.2 --- Structure of β-cyclodextrin --- p.2 / Chapter 1.3 --- Complexation with aromatic compounds --- p.2 / Chapter 1.4 --- Scope of the thesis --- p.6 / Chapter 1.5 --- References --- p.8 / Chapter Chapter 2 --- Synthesis and characterization of β-cyclodextrin epichlorohydrin copolymer --- p.10 / Chapter 2.1 --- Introduction --- p.10 / Chapter 2.2 --- Effects of major parameters on polymerization --- p.11 / Chapter 2.3 --- Polymerization mechanisms --- p.13 / Chapter 2.4 --- Synthesis and characterization of β-cyclodextrin epichlorohydrin copolymer --- p.13 / Chapter 2.5 --- References --- p.18 / Chapter Chapter 3 --- β-Cyclodextrin epichlorohydrin copolymer as a solid-phase extraction sorbent for aromatic compounds --- p.19 / Chapter 3.1 --- Introduction --- p.19 / Chapter 3.2 --- Experimental --- p.22 / Chapter 3.3 --- Results and discussion --- p.25 / Chapter 3.3.1 --- Effect of pH on the extraction of aromatic compounds --- p.25 / Chapter 3.3.2 --- Optimum stirring time for the extraction of aromatic compounds --- p.28 / Chapter 3.3.3 --- Recoveries of aromatic compounds --- p.28 / Chapter 3.3.4 --- Analysis of synthetic standard sample --- p.30 / Chapter 3.4 --- Conclusions --- p.33 / Chapter 3.5 --- References --- p.33 / Chapter Chapter 4 --- Simultaneous determination of Ni(II) and Cu(II) in tea sample by EDXRF after preconcentration with 4-(2-pyridylazo)resorcinol-included β-cyclodextrin epichlorohydrin copolymer --- p.40 / Chapter 4.1 --- Introduction --- p.40 / Chapter 4.2 --- Experimental --- p.41 / Chapter 4.3 --- Results and discussion --- p.45 / Chapter 4.3.1 --- Optimum pH for the inclusion of PAR in β-CDEP cavity --- p.45 / Chapter 4.3.2 --- Saturation time for the inclusion of PAR in β-CDEP cavity --- p.45 / Chapter 4.3.3 --- Optimum pH for the reaction between PAR and metal ions --- p.47 / Chapter 4.3.4 --- Calibration curves and detection limits of Ni(II) and Cu(II) --- p.47 / Chapter 4.3.5 --- Analysis of synthetic standard sample --- p.50 / Chapter 4.3.6 --- Analysis of tea sample --- p.50 / Chapter 4.4 --- Conclusions --- p.53 / Chapter 4.5 --- References --- p.53 / Chapter Chapter 5 --- Conclusions --- p.55

Cette étude concerne la simulation de systèmes thermiques comportant plusieurs domaines à l’aide d’une méthode d’ordre réduit adaptée au mono-corps. Les modèles modaux réduits sont construits à partir de modes de branche. Ceux-ci sont déterminés à l’aide d’un modèle détaillé et permettent la prise en compte de non-linéarités. La réduction est effectuée par la technique de l’amalgame modal découplé qui permet de façon automatique et immédiate d’obtenir une base réduite qui ne comporte qu’un faible nombre de modes à partir de la base initiale. Le couplage entre les différents domaines s’effectue par l’intermédiaire d’une résistance thermique de contact. On montre la nécessité de faire intervenir un terme supplémentaire de pénalisation de saut de flux qui vient améliorer les résultats. Les simulations numériques effectuées sur des cas tests (microprocesseur et radiateur en 2D, bloc métallique avec cartouches chauffantes en 3D) montrent la pertinence de la méthode. / This study concerns the simulation of thermal systems with multiple fields with a reduced-order method suited to a single body. Reduced models are constructed from modal branch eigenmodes. They are determined using a detailed model and allow the inclusion of non-linearities. The reduction is carried out by the simplified amalgam method which allows an automatic and immediate way to obtain a reduced basis which contains only a small number of modes from the original basis. The coupling between the different areas is carried out through a thermal contact resistance. It shows the need to involve an additional flux jump penalty term to improve the results. The numerical simulations carried out on test cases (microprocessor and radiator in 2D, metal block with hot cartridges in 3D) show the relevance of the method.

<p>Techniques for a posteriori error estimation for finite element approximations of an elliptic partial differential equation are studied.This extends previous work on localized error control in finite element methods for linear elasticity.The methods are then applied to the problem of homogenization of periodic structures. In particular, error estimates for the effective elastic properties are obtained. The usefulness of these estimates is twofold.First, adaptive methods using mesh refinements based on the estimates can be constructed.Secondly, one of the estimates can give reasonable measure of the magnitude ofthe error. Numerical examples of this are given.</p>