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Gas-Viscous Liquid Behavior And Its Implications For Pressure-Relief Design, Ahmad H. Alramadneh

Doctoral Dissertations

The two-phase flow system is a multifaceted engineering task with many industrial applications. The accurate prediction of the behavior of such systems is of special importance.

This study is directed toward improving and integrating what is known about the gas-viscous liquid flow behavior during vessel depressurization, specifically, visually characterizing the top venting of saturated-viscous fluids. The experimental results are needed to improve the design methodologies for pressure-relief systems.

Lab-scale vessel depressurization experiments with initially saturated fluids were performed. In particular, a problem arose when sodium tetraborate decahydrate solution (model fluid) saturated with carbon dioxide gas is vented from a 5.3-liter …

Development And Realization Of A Single-Mode Optical Fiber Ferrule Mold Insert With Twelve Channels, Hsiharng William Yang

Doctoral Dissertations

A manufacturing process for an optical fiber ferrule mold insert with twelve channels has been established. This research project presents mask design, mask fabrication, deep X-ray lithography exposure, resist developing, nickel electroforming, as well as surface finishing to attain the final result. Deep X-ray mask fabrication methods are explored, including mechanically machined masks, micro-EDM masks, and E-beam written masks. The exposures to pattern resists and electroforming to fabricate nickel molds up to 500 $\mu$m thickness are reported in this study. Nickel structures for the optical fiber ferrule insert with twelve channels made by electroforming are the final products. A practical …

The Optimized Electrostatic Motor, Christopher Lee Rambin

Doctoral Dissertations

The most common means of electrically activated actuation is the electromagnetic motor. All electromagnetic motors have a low output to weight ratio and low energy efficiency. The motor's weight is due to the coils and magnets used to generate propulsion. The energy loss is mainly the result of Joule heating that is inherent with any current driven device. An electrostatic motor offers the potential of significantly less weight and higher energy efficiency. This lower weight characteristic is due to the epoxide material used to construct the major components of its propulsion unit. Greater efficiency results from the reduced Joule heating …

Fuzzy Logic Applied To System Control To Enhance Commercial Appliance Performance, Glenn Moffett

Doctoral Dissertations

The purpose of this research is to determine the usefulness of fuzzy logic and fuzzy control when applied to a commercial appliance. Fuzzy logic is a structured, model-free estimator that approximates a function through linguistic input/output associations. Fuzzy rule-based systems apply these methods to solve many types of "real-world" problems, especially where a system is difficult to model, is controlled by a human operator or expert, or where ambiguity or vagueness is common.

This dissertation presents fuzzy sets, fuzzy systems, and fuzzy control, with an example conveying the use of fuzzy control of a consumer product and an overview of …

The Effect Of Pipe Bursting On Nearby Utilities, Pavement, And Structures, Alan Atalah

Doctoral Dissertations

This dissertation has involved field and analytical studies of ground movements, ground vibrations and other design issues associated with trenchless pipe replacement (or pipe bursting, as it is commonly known). The process is used to replace an existing underground service pipe with a completely new pipe but without the disturbance and cost of excavating a trench from the surface. The process typically involves the insertion of a tool into the existing pipe that has a maximum diameter that is slightly larger than the existing pipe. This tool is used to break the existing pipe into pieces and to displace the …