A study is presented in which the turbulent behavior of the daytime electrojet, the nighttime upper E region (120-140 km), and the nighttime bottomside F region (150-400 km) are examined near the magnetic equator. The resulting irregularities strongly affect satellite communicat…
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The composition of xenon contained within planetary materials can elucidate the conditions within which they were formed and the environments in which they have resided since formation. This work focused on extracting and interpreting xenon isotopic compositions from primitive m…
Climate change is one of the major challenges of our current era. The amount of greenhouse gas emissions produced by anthropogenic sources has steadily increased since the industrial revolution, in particular CO 2 , which reached a maximum historical concentration of 409.8 ppm i…
This dissertation consists of three essays that use applied econometric analysis and other analytical methods from various economic fields, including regional and urban economics, natural resource economics, housing economics, and sports economics. In all three essays, I use hou…
Since probe theory was developed, the problem of current collection by a charged spherically or cylindrically symmetric body has been investigated by a number of authors (e.g. Parker and Murphy, 1967; Linson, 1969; Laframboise and Rubinstein, 1976). The purpose of this paper is …
The fluid flow patterns in a paper-machine headbox have a strong influence on the quality of the paper produced by the machine. Due to increasing demand for high quality paper there is a need to investigate the details of the fluid flow in the paper machine headbox. The objectiv…
An experimental study was undertaken to elucidate the mixing enhancement and noise reduction in a jet caused by tabs, simple protrusions into the flow, placed at the nozzle exit. Far-field acoustic spectra of underexpanded jets showed the elimination of screech and a decrease in…
Future space systems such as Space Station Freedom, and space defense systems will require storage of cryogenic fluids in a low-gravity environment for extended periods of time. Heat leaks to the containment vessel lead to an increase in the temperature and pressure of the fluid…
Incompressible, viscous, two-dimensional unsteady flows over bluff bodies are simulated via the use of vortex methods. The vorticity domain is discretized into a number of Lagrangian point vortices. The vorticity transport equation is split into convection and diffusion parts, a…
Sensor array systems or electronic noses are efficient analytical tools for detection, monitoring and diagnosis of odors or gases in many applications, e.g. health care, homeland security, manufacturing, and environmental industry, etc. In a sensor array system, the computationa…
A finite volume method for computer simulations of fluids obeying the equation of Bhatnagar, Gross, and Krook (BGK) for ideal fluids is described. The theory is extended to deal with non-ideal fluids. An approach for modeling a van der Waal's fluid is developed and the results o…
Covering the energy demand by using environmentally friendly resources is a major challenge of the present. Gas turbines take a central role in accomplishing this objective, as they allow for bridging periods of a deficit in available renewable energy sources. The application of…
Experiments on nonlinear wave-particle interactions using a traveling wave tube (TWT) are described. There, one or more waves modify the motions of energetic beam particles, and these beam perturbations affect the wave evolution. At large amplitudes, mode-coupling is observed an…
Vortex-induced vibration (VIV) of elastically supported cylinders in cross-flow is studied experimentally for cylinder mass ratios (average cylinder density/fluid density), 2.1 < m* < 72. For small mass ratios below 10, a new VIV mode is discovered which does not involve a lock-…
This work introduces a new pump, called the spiral pump, which targets the surface micromachining technology. We demonstrate the possibility of realizing the spiral pump geometry in standard surface micromachining, lay out the theoretical foundation for its operation, and conduc…
Over the past thirty years, extensive research has been conducted with the objective of reducing wind damage to structures. Wind tunnel simulations of wind loads have been the major source of building codes. However, a simple comparison of pressure coefficients measured in wind …
Investigations have been made of the aerodynamic effects of in-service damage on the performance of axial turbine blades. Two aspects of blade damage were considered: surface roughening and trailing edge damage. The work is related to gas turbine engine health monitoring. Correl…
Quantifying and controlling the radiative power losses from impurities in the tokamak fusion plasma is crucial for obtaining ignition conditions. In the present work, therefore, losses from impurities have been measured in different operating regimes of the Alcator C-Mod Tokamak…
This thesis addresses three problems in seismology and volcanology by applying fluid dynamical theories that have been developed for engineering applications. Fault zones are proposed to operate analogously to journal bearings. A quantitative assessment of the physical regimes i…