The programme of research reported in this dissertation was undertaken with the aim of improving the high-speed performance of a multi-recessed hydrostatic thrust bearing. A theoretical analysis of the quasi-static behaviour and isothermal frictional power consumption is developed using the basic equations governing viscous fluid flow. The effects of high peripheral speeds are discussed and how recently proposed bearing modifications, in the form of grooved lands and changes in recess geometry, are used to reduce the frictional power consumption, lower operating temperatures, and reduce unwanted hydrodynamic and fluid inertia induced pressure variations. The steady state temperature distribution, frictional power consumption and operating clearance when one bearing member is rotating, and dynamic loading performance are predicted by several specially developed Fortran computer programs. One section concentrates on the design, development and instrumentation of an experimental multi-recessed hydrostatic thrust bearing, which had a facility for changing the pocket geometry using recess inserts. The bearing plate. which had an outside diameter of 200 mm, was operated at rotational speeds between 1000-5000 rpm to give peripheral speeds between 10.5 - 52.5 m/s. A chapter deals with an experimental investigation of the high-speed performance of a multi-recessed hydrostatic thrust bearing, principally the quasi-static loading and flow rate characteristics, temperature and pressure distributions and frictional power consumption. Furthermore, the dynamic response of the test bearing arrangement was investigated experimentally for a range of excitation frequencies between 0- 70 Hz- Finally, the theoretical predictions of characteristics such as quasi-static loading and flow rate, steady state operating conditions and dynamic response are compared with the corresponding experimental results.

No description available.

The design and construction of an electrochemical detector with two working electrodes located on the opposite walls of a thin-layer cell and its use as a detector for High Pressure Liquid Chromatography (HPLC) in the analysis of catecholamines in human cerebrospinal fluid are described. The location of the electrodes in this manner permits an electrochemically reversible or quasireversible couple to be electrolized more than once as it passes through the detector. If one electrode is held at a potential where oxidation takes place and the second electrode at a potential where reduction of this oxidized form back to the starting material occurs, then the current produced increases proportionately to the number of conversions that take place. A comparison of this cell in the dual-working-electrode and single-working-electrode mode shows an improvement in the signal-to-noise ratio by a factor of six. This HPLC system with electrochemical detection has been used for the first time to detect norephinephrine (141 pg/mL) and dopamine (262 pg/mL) in human cerebrospinal fluid.

No description available.

<div>The objective of this dissertation is to develop new methods in the areas of multiscale topology optimization, thermomechanical topology optimization including heat convection, and thermal-fluid topology optimization. The dissertation mainly focuses on developing five innovative topology optimization algorithms with respect to structure and multistructure coupling fluid, thermal and mechanical analysis, in order to solve customary design requirements. Most of algorithms are coded as in-house code in MATLAB.</div><div><br></div><div><div>In Chapter One, a brief introduction of topology optimization, a brief literature review and the objective is presented. Five innovative algorithms are illustrated in Chapter Two</div><div>to Six. From Chapter Two to Four, the methods with respect to multiscale approach are presneted. and Chapter Five and Six aims to contribute further research associated with</div><div>topology optimization considering heat convection. In Chapter Two, a multiphse topology optimization of thermomechanical structures is presented, in which the optimized structure is composed of several phases of prescribed lattice unit cells. Chapter Three presents a</div><div>Multiscale, thermomechanical topology optimization of self-supporting cellular structures. Each lattice unit cell have a optimised porousity and diamond shape that benefit additive</div><div>manufacturing. In Chapter Four, the multiscale approach is extended to topology optimization involved with fluid mechanics problem to design optimized micropillar arrays in</div><div>microfludics devices. The optimised micropillars minimize the energy loss caused by local fluid drag force. In Chapter Five, a novel thermomechanical topology optimization is developed, in order to generate optimized multifunctional lattice heat transfer structure. The algorithm approximate convective heat transfer by design-dependent heat source and natural convection. In Chapter Six, an improved thermal-fluid topology optimization method is created to flexibly handle the changing of thermal-fluid parameters such as external heat source, Reynolds number, Prandtl number and thermal diffusivity. The results show the</div><div>changing of these parameters lead versatile optimized topologies. Finally, the summary and recommendations are presented in Chapter Seven.</div></div><div><br></div>

Reservoir fluids are rarely found in homogeneous structures having homogeneous properties. The various elements and processes of the petroleum system result in complex fluid distributions and compositions. A sound understanding of these complexities can avoid disappointing results and costly mistakes when designing the completion and production of the reservoir. The earlier these complexities are understood in the exploration phase, the better are the chances of a successful decision making process in the design phase of the project. Assessing reservoir compartment connectivity is of paramount importance for a optimal field development. Recent technological advances in wireline formation testing and sampling provide asset teams with a new methodology to evaluate in situ fluid properties and reservoir connectivity. After a review of the technology of downhole fluid analysis (DFA), the currently available methods of modeling equilibrated fluid gradients are presented. Fluid composition equilibrium is a stationary state where all components have reached zero mass flux. A reservoir model is designed to simulate numerically equilibration processes over geologic timescales at isothermal conditions where diffusion and gravity are the active mechanisms. A variety of initial conditions and reservoir fluid types is considered. Non-equilibrium fluid gradients and their transient behavior as they evolve towards fluid composition equilibrium are the main interest of this study. The results are compared in case studies, that are available in published literature. The modeling methods allow modeling of vertical and lateral fluid gradients. After a discussion of the cases, this thesis gives recommendations on 1) what fluid properties should be assessed and 2) how many data points are needed to reduce the chance of misinterpretation of non-equilibrium gradients in the presence of faults. To make best use DFA data, the property that exhibits the largest gradient needs to be investigated, as it yields the greatest potential to assess connectivity. The shape of the distribution of fluid composition within a compartment is found to be an important part in investigating reservoir connectivity. During data acquisition efforts should be made to acquire enough data points to reveal this shape. In combination with the presented techniques to identify non-equilibrium conditions, this will optimize DFA data acquisition and maximize the value of the data.

An evaluation of a series of interventions was conducted for an individual who engaged in life-threatening rumination and emesis. There is substantial research indicating that the delivery of peanut butter (Barton & Barton, 1985; Greene, Johnston, Rossi, Racal, Winston, & Barron, 1991) and/or chopped bread following meals (Thibadeau, Blew, Reedy, & Luiselli, 1999), chewing gum (Rhine & Tarbox, 2009), and satiation procedures (Dudley, Johnston, & Barnes, 2002; Lyons, Rue, Luiselli, & DiGennario, 2007; Rast, Johnston, Drum, & Conrin, 1981) can be effective treatments for rumination. In the current case, each of these interventions was found to be either ineffective or contraindicated based on the participant's fragile health status. Previous literature has shown that liquid delivery can affect rates of rumination in some clients (Barton & Barton, 1985,; Heering, Wilder, & Ladd, 2003). We examined how liquid affected the rate of rumination during and after meals. Based on the individual's medical condition, oral nutrition and fluids were discontinued indefinitely and a gastronomy-jejunostomy tube was used for nutrition. All rumination ceased when fluids and nutrition were delivered via the jejunostomy tube. Finally, a fluid analysis procedure was implemented in which the participant received small amounts of fluid while NPO. Color and flavor were manipulated systematically, and results suggested that flavor impacted the rate of rumination.

The objective of this study is to computationally investigate the vorticity generated by the wake of a (1) rotor blade and a (2) hydrofoil profile. The first flow is weakly compressible and is inspired by experiments carried out by Dr. Tinney at The University of Texas at Austin aimed at investigating the aeroacoustic effects of blade-vortex interactions. The second flowis inspired by experiments carried out by Dr. Irvine at the University of Chicago where a ring with a hydrofoil-shaped cross-section is pulled in water to create a coherent vortical structure. Simulations have been carried out with the high-order unstructured block-spectral code solverH3AMR. The rotor blade simulations have been performed at the nominal angle of attackof 7.4°where an unsteady vortical wake with quasi-periodic shedding was observed together with a surprising dependency of the lift coefficient on the thermal boundary conditions: the lift coefficient is predicted to increase from 0.96 to 1.14 when switching from adiabatic to isothermal no-slip conditions. The hydrofoil calculations were run with steady free-stream conditions (not matching the experiments) and showed massively separated flow on the suction side due to the high angle of attack.

This work is focused on the dynamic effects with regard to impact of wind on a slender bridge structure, namely a variant of an overhead footbridge for pedestrians and cyclists, over a river. Attention is focused on finding the so-called default steady state, as well as modal analysis, where owen frequencies are calculated, which is the basis for further dynamic assessment. The main part is focused on modeling in a fluid field of ANSYS CFX, where the effects of wind on the structure are defined and calculated. The goal of the work is to make a dynamic response to vortex excitation and, on the basis of analysis, to assess the fatigue design.

- Creo 5.0 enhancements - New extensions: Creo Flow Analysis, Topology Optimization - Futures