In the Mojave Pegmatite district, located in northwestern AZ, numerous pegmatites intrude syn- to post-collisional Paleoproterozoic granitic rocks. The slightly older Cerbat plutons are associated with the suturing of the Mojave and Yavapai terranes whereas Aquarius granites were emplaced during the Yavapai Orogeny as the sutured terranes docked with North America. A detailed study of 5 pegmatites shows that they are zoned with composite cores and contain REE minerals characteristic of NYF pegmatites. However, they exhibit characteristics atypical for NYF pegmatites including F depletion, white microcline, an absence of columbite and, in the Rare Metals pegmatite, have muscovite and beryl. With the exception of the Kingman pegmatite, they exhibit normal LREE-HREE distributions. The Kingman pegmatite is extremely LREE enriched, HREE depleted and exhibits an unusual Nd enrichment which, in some cases, is sufficiently high that allanite is Nd dominant, thus a new mineral species, allanite-Nd.

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Chung Tsz Shun Eric. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 102-104). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Applications of Maxwell's equations --- p.1 / Chapter 1.2 --- Introduction to Maxwell's equations --- p.2 / Chapter 1.3 --- Historical outline of numerical methods --- p.4 / Chapter 1.4 --- A new approach --- p.5 / Chapter 2 --- Mathematical Backgrounds --- p.7 / Chapter 2.1 --- Sobolev spaces --- p.7 / Chapter 2.2 --- Tools from functional analysis --- p.8 / Chapter 3 --- Discretization of Vector Fields --- p.10 / Chapter 3.1 --- Domain triangulation --- p.10 / Chapter 3.2 --- Mesh dependent norms --- p.11 / Chapter 3.3 --- Discrete circulation operators --- p.13 / Chapter 3.4 --- Discrete flux operators --- p.20 / Chapter 4 --- Spatial Discretization of the Maxwell's Equations --- p.23 / Chapter 4.1 --- Derivation --- p.23 / Chapter 4.2 --- Consistency theory --- p.29 / Chapter 4.3 --- Convergence theory --- p.33 / Chapter 4.3.1 --- Polyhedral domain --- p.33 / Chapter 4.3.2 --- Rectangular domain --- p.38 / Chapter 5 --- Fully Discretization of the Maxwell's Equations --- p.63 / Chapter 5.1 --- Derivation --- p.63 / Chapter 5.2 --- Consistency theory --- p.65 / Chapter 5.3 --- Convergence theory --- p.69 / Chapter 5.3.1 --- Polyhedral domain --- p.69 / Chapter 5.3.2 --- Rectangular domain --- p.77 / Chapter 6 --- Numerical Tests --- p.97 / Chapter 6.1 --- Convergence test --- p.97 / Chapter 6.2 --- Electromagnetic scattering --- p.99 / Bibliography --- p.102

Chan Ming-Ho Gordon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 104-105). / Abstracts in English and Chinese. / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- BACKGROUND ON MICRO POWER SUPPLY --- p.1 / Chapter 1.1.1 --- Brief Introduction --- p.1 / Chapter 1.1.2 --- Proposed Applications of Micro Power Supplies --- p.3 / Chapter 1.1.3 --- Comparison Among Different Power Sources --- p.4 / Chapter 1.2 --- LITERATURE SURVEY --- p.8 / Chapter CHAPTER 2 --- MICRO POWER GENERATOR WITH COPPER SPRINGS --- p.10 / Chapter 2.1 --- POWER PRODUCTION FROM MECHANICAL VIBRATIONS: SYSTEM ANALYSIS --- p.10 / Chapter 2.2 --- DESIGN OF MICRO RESONATING SPRING --- p.16 / Chapter 2.2.1 --- Design Objective --- p.16 / Chapter 2.2.2 --- Material Selection --- p.18 / Chapter 2.2.2.1 --- Mechanical Resonating Structure --- p.18 / Chapter 2.2.2.2 --- Electromagnetic Structure --- p.23 / Chapter 2.3 --- LASER MICROMACHINING OF SPRING STRUCTURE --- p.26 / Chapter 2.3.1 --- Si Bulk Micromachining --- p.26 / Chapter 2.3.2 --- Laser Micromachining --- p.28 / Chapter CHAPTER 3 --- COMPUTER SIMULATION --- p.31 / Chapter 3.1 --- TRANSIENT VOLTAGE AND POWER OUTPUT --- p.31 / Chapter 3.2 --- SYSTEM RESPONSE WITH VARYING PARAMETERS --- p.35 / Chapter CHAPTER 4 --- FINITE ELEMENT ANALYSIS --- p.39 / Chapter 4.1 --- STRUCTURAL STATIC ANALYSIS --- p.41 / Chapter 4.1.1 --- Building a Model --- p.41 / Chapter 4.1.2 --- "Material, Loading And Boundary Condition" --- p.45 / Chapter 4.1.3 --- Comparison Between Generator Designs --- p.46 / Chapter 4.2 --- MODAL ANALYSIS AND HARMONIC RESPONSE ANALYSIS --- p.51 / Chapter 4.3 --- NONLINEARITY --- p.52 / Chapter CHAPTER 5 --- COMPARISON OF MODELING AND EXPERIMENTAL RESULTS --- p.55 / Chapter 5.1 --- EXPERIMENT SETUP --- p.55 / Chapter 5.1.1 --- Generator System --- p.55 / Chapter 5.1.2 --- Vibration and Measurement --- p.60 / Chapter 5.2 --- MODELING AND EXPERIMENTAL COMPARISON --- p.62 / Chapter 5.2.1 --- Voltage and Power Comparison --- p.64 / Chapter 5.2.2 --- Mechanical Response --- p.66 / Chapter CHAPTER 6 --- SUGGESTIONS FOR POWER GENERATOR WITH RESONATING FREQUENCY BELOW 10HZ --- p.77 / Chapter CHAPTER 7 --- CONCLUSION --- p.80 / BIBLIOGRAPHY --- p.104

In this PhD some key computational and algorithmic aspects of the Combined Finite Discrete Element Method (FDEM) are critically evaluated and either alternative novel or improved solutions have been proposed, developed and tested. In particular, two novel algorithms for contact detection have been developed. Also a comparative study of different contact detection algorithms has been made. The scope of this work also included large and grand scale FDEM problems that require intensive use of CPU; thus, novel parallelization solutions for grand scale FDEM problems have been developed and implemented using the MPI (Message Passing Interface) based domain decomposition. In this context a special attention is paid to the rapidly developing multi-core desktop architectures. The proposed novel solutions have been intensively validated and verified and demonstrated using various problems from literature.

Masonry arch bridges still play an important role in the transportation infrastructure today in the United Kingdom. Previous research has mainly focused on the load carrying capacity in the span direction. The three dimensional behaviour is often investigated by simplifying into two dimensions with modified arch parameters but these simplified analyses cannot represent all aspects of behaviour. Spandrel wall failure in some railway masonry arch bridges has raised concerns recently, and this is one aspect which cannot be modelled in two dimensions. This thesis presents a research which attempts to model the interaction behaviour between arch, backfill and spandrel wall with the aim of representing the three dimensional nature of real bridges. It mainly focuses on the spandrel wall defects under increasing load, including crack development across the wall and longitudinal cracks in the arch barrel underneath spandrel wall. Experimental results from the laboratory tests on engineering blue brick and a hydraulic premixed mortar as well as brickwork masonry specimens are presented. Numerical analysis was initially performed on these brickwork masonry specimens for validation. Three dimensional FE models were proposed for both small and large scale bridges. The general behaviour of the small scale bridge under rolling load and large scale bridge under increasing load were studied. Reasonable agreement between the FE analyses and experimental results from previous literature was obtained, indicating the model validated for small masonry specimens could be scaled up to full-scale bridges. A series of computer models were constructed to investigate the relationship between a range of geometric and material parameters and the lateral behaviour of arch bridges. The backfill depth and spandrel wall thickness have greatest impact on both bridge strength and lateral behaviour. The fill properties also have an importance influence on the load carrying capacity. This provides an indication of which bridge should be more closely monitored for spandrel wall defects. Separate FE models was constructed to simulate existing longitudinal cracks found in the arch barrel for old bridges and the influence of strengthening of spandrel wall with tie bars. The general behaviour under a concentrated load is studied and discussed. It has been demonstrated that it is possible to effectively model the three dimension behaviour of masonry arch bridges and in particular, spandrel wall failures.

"A numerical description of the extraordinary optoconductance (EOC) effect is presented using two separate models. Extraordinary optoconductance is part of a general class of EXX geometric effects involving the external perturbation of the properties of a 2D electron gas in a macroscopic semiconductor or metal-semiconductor hybrid structure. The addition of metallic inclusions, has been shown to increase the sensitivity of devices relying on EXX effects. Following the discovery of the first EXX effect, extraordinary magneto-resistance (EMR), an optical equivalent was suggested. Unlike EMR, where the external perturbation is an applied magnetic field, EOC results from the modification of the local charge density in the semiconductor by a focused laser. The first model assumes Gaussian charge densities for the photo-generated electron-hole pairs while the second model directly solves the semiconductor drift-diffusion equations using the finite element method (FEM). Results from both models are shown to agree with experimental EOC data, both as a function of the laser spot position and temperature. The FEM model has the ability to describe EOC in more complex geometries making it useful in designing EOC devices geared for particular applications. "

"Certain physical problems in electrostatics, magnetostatics, and heat transfer give rise to elliptic boundary value problems with transmission conditions on a layer. We focus on a particular problem with a second order transmission condition, representing an infinitely conductive layer. To approximate irregular layers that may naturally arise, a sequence of layers that converge to the fractal von Koch curve is considered. The solution to this transmission problem with a prefractal layer exhibits singularities due to the transmission condition across the layer as well as the reentrant corners introduced in the domain by the prefractal curve. To solve this problem numerically using a finite element method, the mesh must be adjusted to account for these singularities. We exhibit a general algorithm for creating a finite element discretization of the domain that results in linear convergence of the numerical solution to the true solution in a suitable norm."

"The purpose of this project is to design a non-snagging guardrail post. The procedure will be to first develop a simple finite element (FE) model of a single post, wheel and suspension to explore the snag potential for some existing standard guardrail posts. The next step in the procedure will be to develop appropriate design changes that could prevent wheel snagging and investigate if they do by using a one-post sub-model. An attempt to validate the used material model for wood will also be done by comparison between laboratory tests and finite element simulations."

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