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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 Effects Of Consideration And Initiating Structure Exhibited By Principals On Teacher Morale In Selected Louisiana Secondary Schools, Robert Wayne Webber

Doctoral Dissertations

This study was conducted to determine whether a statistically significant relationship exists between the leadership styles of principals and teacher morale in the public secondary schools of north Louisiana, as perceived by teachers. The Ohio State studies and Getzels and Guba's Social Systems Model for educational organizations provided the theoretical framework for this study. Selected demographic variables of gender of the teacher, years of teaching experience, and race of the teacher were considered in this study. Information on teacher morale was collected from teachers in 14 randomly selected schools of north Louisiana. Data were obtained concerning teacher morale using the …

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 …

An Empirical Analysis Of The Relationships Among Entrepreneurial Orientation, Organizational Culture And Firm Performance, Kenneth Herbert Chadwick

Doctoral Dissertations

The objective of this dissertation was to empirically assess the entrepreneurial orientation (EO) to firm performance relationship and the potential influence of organizational culture (OC). Specifically, OC was examined as a potential predictor of the degree of EO and as a potential moderator of the EO to performance relationship. Firm performance was assessed with the weighted average performance scale and 1997 year ending return on assets (ROA) and return on equity (ROE).

The sample frame consisted of a national sample of bank presidents. The mailing list was purchased from Thomson Financial Publishing. A self-report questionnaire was mailed to a stratified …

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 …

Transactional Bond In The Novels Of Charles Brockden Brown, Gretchen Elspeth Digeronimo

Doctoral Dissertations

The six novels and various other fiction pieces Charles Brockden Brown wrote between 1799 and 1801 coherently demonstrate the operation and effect of literary and artistic representation in early Republican America.

In original close readings of Arthur Mervyn, Edgar Huntly, Ormond, and several other works, this dissertation identifies transactional bond and describes how Brown charted the establishment of the public and private individual self through transactional bond in three specific arenas: relationships between the developing self and written, visual, or reported representation; relationships between master/mentors and apprentices; relationships among women.

Bonds that begin, operate, and dissolve between male characters are …

Fluid-Structure Interaction In Taylor-Couette Flow, Martin Horst Willi Kempf

Doctoral Dissertations

The linear stability of a viscous fluid between two concentric, rotating cylinders is considered. The inner cylinder is a rigid boundary and the outer cylinder has an elastic layer exposed to the fluid. The subject is motivated by flow between two adjoining rollers in a printing press. The governing equations of the fluid layer are the incompressible Navier-Stokes equations, and the governing equations of the elastic layer are Navier's equations. A narrow gap, neutral stability, and axisymmetric disturbances are assumed. The solution involves a novel technique for treating two layer stability problems, where an exact solution in the elastic layer …

Alternative Removal Methodologies For Environmental Waters, Shannon Patrick Hogan

Doctoral Dissertations

The Environmental Protection Agency (EPA) continues to establish criteria for the reduction of pathogens in environmental waters used for drinking water. The EPA also states criteria on the amount of chlorine by-products allowed in drinking water. Alternative removal methods that are used in conjunction with chlorine are needed to assure safe drinking water.

The Surface Water Treatment Rule (SWTR) states that a 99.99% reduction of viruses and a 99.9% reduction in Giardia lamblia cysts needs to be achieved by a treatment facility that uses surface water for the production of drinking water. The SWTR also states Maximum Contaminant Levels (MCL) …

Timber Price Trends, Jack Lutz

Doctoral Dissertations

Timber price forecasts are important components of timberland investment analysis. Econometric models used in forecasting timber prices can be complex because demand for timber is derived through demand for other products such as paper and housing. In contrast to econometric methods, time series analysis or autoregressive techniques allow price forecasts to be made from the timber price series themselves.

A necessary condition for using time series techniques is that the timber price series be stationary or mean-reverting. The primary hypothesis in this study was that timber prices would not be stationary and time series techniques could not be applied to …

Music And The General Classroom: Literacy In A New Key, F Dan Seger

Doctoral Dissertations

After a personal description of the traditional role of music education and its relationship to the overall curriculum of an American elementary school, this dissertation asks: What do grade 4/5 students do when their classroom and music teachers integrate music more deliberately into classroom life? Set in a classroom in a small New England town, the dissertation describes how a collaboration between a classroom teacher and a music teacher brought the music curriculum into the daily lives of students in a school where scheduled music class occurred only once per week.

Viewing music as a valid means to represent thought …

New Synthetic Routes To Strained Cumulenes And Reactive Carbenes, Susana Hernandez

Doctoral Dissertations

I. The synthesis, trapping, and strain energy estimates for cyclic butatrienes are described. Four fundamental questions have been investigated: kinetic stability limitations, molecular strain, structural limitations, and the development of a general synthetic route applicable to different ring sizes.

1,2,3-Cyclooctatriene (9) has been generated by magnesium induced 1,2-elimination on 2-bromo-3-chloro-1,3-cyclooctadiene (4). Synthesis of the eight-membered ring completes the C$\sb6$-C$\sb{10}$ series of cyclic butatrienes. This substance shows moderate kinetic stability, but is readily trapped in a ($\rm\sb\pi2\sb{s}{+}\sb\pi4\sb{s}\rbrack$ cycloaddition with diphenylisobenzofuran or 2,5-dimethylfuran. The total strain energy and the strain in the butatriene moiety in cumulene 9 have been assessed by ab …

Issues Of Engendered Entitlement: Who Owns The Classroom? Who Owns Knowledge?, Dorothy Radius Kasik

Doctoral Dissertations

This dissertation examines the ways in which first year female college students have been prepared by educational systems in our culture to handle knowledge and the acquisition of knowledge during the first year of college experience. It is the contention of the author that women are not actively encouraged in our culture to take ownership of educational concepts in the same way as men. This happens for two reasons, first that because women's methods of interaction in the classroom might differ from men's those methods might not be perceived as acceptable or taken seriously; and second that a woman's discomfort …

Controls On Ch(4) Emissions From Boreal And Arctic Wetlands, Sadredin Cyrus Moosavi

Doctoral Dissertations

This thesis examines the environmental controls on the biogeochemical cycling of the radiatively active trace gas CH$\sb4$ within boreal and arctic wetlands. Net CH$\sb4$ flux along peatland hydrologic gradients were examined to determine the effects of temperature and water table on CH$\sb4$ emissions. The level of the water table acts as a switch between CH$\sb4$ production and oxidation with small water level changes producing large changes in flux balance. Soil temperature determined whether CH$\sb4$ production potential was realized within sufficiently moist environments. A selective inhibitor technique was developed for directly measuring CH$\sb4$ oxidation in wetland soils. CH$\sb4$ oxidation was found …

The Influence Of Chloride On Interface Kinetics And Morphology Of Copper Electrodeposits On Copper Single Crystals, Qunwei Wu

Doctoral Dissertations

The influence of chloride on the kinetics and morphology of copper electrodeposition on copper single crystal in acidified copper sulfate solution was studied by atomic force microscopy (AFM) and by electro-analytical methods. AFM was employed to image deposits on low-index single crystal copper surface formed under potential control in a fluid electrolyte. The kinetic parameters for cathodic deposition of copper on the same surface from acid sulfate and chloride solution were measured by galvanostatic polarization.

Chloride has a great influence on the morphology of copper deposits Isotropic structures were obtained only in high purity sulfate solution, whereas anisotropic structures emerged …

A Very High Level Logic Synthesis, Norbert Ange Valverde

Doctoral Dissertations

The evolution of Computer Aided Design (CAD) calls for the incorporation of design specifications into a microelectronics system development cycle. This expansion requires the establishment of a new generation of CAD procedures, defined as Very High Level Logic Synthesis (VHLLS). The fundamental characteristics of open-ended VHLLS are: (1) front-end graphical interface; (2) time encapsulation; and (3) automatic translation into a behavioral description. Consequently, the VHLLS paradigm represents an advanced category of CAD-based microelectronics system design, built on a deep usage of expert systems and intelligent methods. Artificial Intelligence (AI) formalisms such as Knowledge Representation System (KRS) are necessary to model …

Effects Of Non-Maxwellian Auroral Source Electrons, Eric Edward Dors

Doctoral Dissertations

The auroral current density-voltage and energy flux density-voltage relationships are derived under the assumption that magnetospheric electrons above the auroral acceleration region are described by the $\kappa$ distribution function. To illustrate the effects of this boundary condition on auroral precipitation, a two dimensional model of auroral electrodynamics similar to that of Lyons (1980) has been developed by imposing current continuity in the auroral zone. The current carried by precipitating magnetospheric electrons inside auroral arcs connects to return current regions at the arc edges via ionospheric Pedersen currents. A key feature is the ability to parameterize the magnetospheric boundary electron population …

Sensors Forph Based On Swelling And Reflectivity Of Derivatized Polystyrene Beads And Membranes, Li Zhang

Doctoral Dissertations

Kraton-modified amine-derivatized poly(vinylbenzyl chloride) beads prepared by suspension polymerization are sensitive to pH. They swell in acid due to protonation of amine groups and shrink in base. Polymer swelling generates a measurable swelling signal that is related to the concentration of hydrogen ions in solution. The sensor responded to pH in the range from 6.0 to 10.0. Bead size, level of porogenic solvents and Kraton G1652 affected the magnitude of sensor response and response time.

Diethanolamine derivatized poly(VBC) membranes formulated with a small amount of Kraton G1652 reflect light. At low pH membranes turn clear. The observed optical change is …

Stability And Weight Smoothing In Cmac Neural Networks, David Paul Campagna

Doctoral Dissertations

Although the CMAC (Cerebellar Model Articulation Controller) neural network has been successfully used in control systems for many years, its property of local generalization, the availability of trained information for network responses at adjacent untrained locations, although responsible for the networks rapid learning and efficient implementation, results in network responses that is, when trained with sparse or widely spaced training data, spiky in nature even when the underlying function being learned is quite smooth. Since the derivative of such a network response can vary widely, the CMAC's usefulness for solving optimization problems as well as for certain other control system …

Total Quality Management And Corporate Financial Performance: An Analysis Of The Malcolm Baldridge National Quality Award Criteria, Alice Brigid Beechner

Doctoral Dissertations

"The impact of the Malcolm Baldrige National Quality Award (MBNQA) Performance Excellence Criteria on corporate financial performance is examined. Three independent studies were performed to assess this relationship. The first included Malcolm Baldrige National Quality Award (MBNQA) winners. The second study involved 69 firms identified as Total Quality Management (TQM) firms and for the final study a sample of large American corporations who completed surveys which provided an estimate of the score the companies would have received on a MBNQA assessment were examined. The method for assessing the financial strength for all three studies was the metric Market Value Added …

Union Commitment: A Two-Sample Multivariate Analysis Of A Professional White-Collar Union Local And A Typical Blue-Collar Manufacturing Union Local, Arthur Lee Pevahouse

Doctoral Dissertations

This study assesses union commitment using a quasi-experimental methodology to determine and test the hypothesis that there is no difference in commitment levels of white-collar and blue-collar union workers. A self reporting pencil and paper survey instrument was used to gather the data. Two specific union locals in the same area were chosen to participate in the survey. One local was a white-collar, engineering local and the other was a tire manufacturing local. These two locals were chosen on the basis of location and attributes that met the research requirements.

There were ten hypotheses formulated that contended that the level …

Investigation Of The Effects Of Nosetip Shape In Terminal Ballistics Using A Wave Mechanics Model, Jack Scott Mcmurtry

Doctoral Dissertations

The purpose of this work is to delineate some of the physical mechanisms which govern the effect of nosetip shape on terminal ballistics phenomenology. A principal goal in the study of terminal ballistics has been the prediction of depth of penetration and crater diameter for penetrators and targets of various geometries, sizes, and materials. The model developed here is based on a "quasi-steady wave" mechanics approach to the problem with a 1-D model for the penetrator and a 2-D model for the target. The model is based on the application of the conservation of momentum equation to a control volume …

Expectation-Performance Gap: Professional Liability Associated With Certain Auditor Behaviors, Sidney Paul Glandon

Doctoral Dissertations

The purpose of this dissertation is threefold: (i) to establish hypotheses relating financial liability to certain auditor behaviors discussed in the independence literature, (ii) to empirically validate that the presence of these behaviors will increase auditor financial liability over the normal audit situation, and (iii) attempt to explain the differences in subjects' perceptions for each of the behavioral scenarios studied.

A survey instrument was developed and administered to three groups of subjects: an impaneled jury, bankers, and CPAs. The instrument contained a vignette describing an annual audit situation where the company filed for bankruptcy subsequent to the issuance of the …

Myoglobin-Facilitated Oxygen Diffusion In The Heart: A Mathematical Assessment, Jason D. Gardner

Doctoral Dissertations

Myoglobin facilitated oxygen diffusion and Michaelis-Menten kinetics are added to an experimentally-validated cardiac tissue model to determine the steady-state function of myoglobin in working heart tissue. Previous modeling of tissue oxygen partial pressure (pO$\sb2)$ data suggests that the oxygen diffusion coefficient in working heart tissue is greater than expected. To fit the pO$\sb2$ data, the tissue oxygen diffusion coefficient in the model must be elevated to 8 to 12 times reported values. These elevated values of the tissue oxygen diffusion coefficient are not acceptable based upon the current understanding of cardiac muscle physiology. In this dissertation the effect of including …

Two-Phase Flow In Microchannels, Roger Scott Stanley

Doctoral Dissertations

The purpose of this study was to investigate fluid mechanic and heat transfer characteristics of two-phase two-component flow in rectangular microchannels. Experiments were conducted using rectangular aluminum channels with hydraulic diameters ranging between 56 $\mu$m and 256 $\mu$m and aspect ratios which varied from 0.5 to 1.5. Both single- and two-phase tests were conducted using water and gaseous argon, helium, and nitrogen as the working fluids. The Reynolds number for both types of experiments ranged from approximately 50 to nearly 10,000. The Nusselt number ranged between 0.0002 and 70. The single- and two-phase experimental data were empirically correlated, using parameters …

Dynamic Response Of Poroelastic Materials Containing Bingham Fluid: Application To Electrorheological Fluids, Mete Kesan

Doctoral Dissertations

This work examines the dynamic response to harmonic loading of a disk of poroelastic material containing non-Newtonian Bingham fluid which exhibits a yield stress. Biot's poroelasticity equations and modified Darcy's law for non-Newtonian fluids exhibiting a yield stress are combined together to obtain the governing equations of the system for quasi-static case. Dissipation due to friction arising from the flow of fluid relative to the solid is taken into account but inertia effects are neglected. The response and the complex modulus of the system are calculated using the finite element method taking into account the nonlinear nature of Bingham fluid. …

A Sensory-Based Adaptive Walking Control Algorithm For Variable Speed Biped Robot Gaits, Andrew L. Kun

Doctoral Dissertations

A balance scheme for handling variable speed gaits was implemented on an experimental biped. The control scheme used pre-planned but adaptive motion sequences in combination with closed loop reactive control. CMAC neural networks were responsible for the adaptive control of side-to-side and front-to-back balance. The biped performance improved with neural network training. The biped was able to walk with variable speed gaits, and to change gait speeds on the fly. The slower gait speeds required statically balanced walking, while the faster speeds required dynamically balanced walking. It was not necessary to distinguish between the two balance modes within the controller. …

Adaptive Multiresolution Visualization Of Large Multidimensional Multivariate Scientific Datasets, Pak Chung Wong

Doctoral Dissertations

The sizes of today's scientific datasets range from megabytes to terabytes, making it impossible to directly browse the raw datasets visually. This presents significant challenges for visualization scientists who are interested in supporting these datasets. In this thesis, we present an adaptive data representation model which can be utilized with many of the commonly employed visualization techniques when dealing with large amounts of data. Our hierarchical design also alleviates the long standing visualization problem due to limited display space. The idea is based on using compactly supported orthogonal wavelets and additional downsizing techniques to generate a hierarchy of fine to …

An Experimental Investigation Of The Effects Of Elastic Modulus And Yield Strength On Fracture Surface Interference In Shear Loaded Cracks, Ronald U. Goulet

Doctoral Dissertations

An experimental process was developed to study the effects of material properties on fracture surface interference in Mode II loaded cracks in 7075 aluminum. 4340 and 8642 steels. Factors studied included elastic modulus, yield strength, mode mixity and fracture surface geometry. An asymmetric four point bend specimen and fixture was developed to apply pure Mode II and mixed Mode I and II loads to edge cracks. Three dimensional displacement fields were measured as a function of applied load using an electro-optical holographic interferometric facility. Stress intensity factors were obtained by fitting observed 2-D field displacements to basis functions derived from …