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Theses/Dissertations

1995

Physical Sciences and Mathematics

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Full-Text Articles in Engineering

A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare Dec 1995

A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare

Master's Theses

Over a two year period, Western Michigan University ran a number of pump tests in the Asylum Lake Area in Kalamazoo, Michigan. The transmissivities and storativities calculated from these tests differed significantly from well to well in any particular test, and from pump test to pump test. Utilizing the computer programs AQTESOLV 3.0 and Aquifer Parameter Estimator, a number of T and S values were calculated. After analysis of the results, the following conclusion was drawn. The main reason for the deviations in the T and S values arose from the mixing of the results of numerous methods (some ...


Atomic Broadcast In Heterogeneous Distributed Systems, Osman Zeineldine Oct 1995

Atomic Broadcast In Heterogeneous Distributed Systems, Osman Zeineldine

Computer Science Theses & Dissertations

Communication services have long been recognized as possessing a dominant effect on both performance and robustness of distributed systems. Distributed applications rely on a multitude of protocols for the support of these services. Of crucial importance are multicast protocols. Reliable multicast protocols enhance the efficiency and robustness of distributed systems. Numerous reliable multicast protocols have been proposed, each differing in the set of assumptions adopted, especially for the communication network. These assumptions make each protocol suitable for a specific environment. The presence of different distributed applications that run on different LANs and single distributed applications that span different LANs mandate ...


Preprocessing Of Microcirculatory Images., Mohamed S. Mansour Aug 1995

Preprocessing Of Microcirculatory Images., Mohamed S. Mansour

Electronic Theses and Dissertations

This thesis project consists of the development of a computerized image processing system to preprocess microvascular images of the mouse Latisimus Dorsi Muscle (LDM). This research has been conducted in association with the Division of Plastic and Reconstructive Surgery at the University of Louisville. The input to the system is a set of 35 or more overlapping microscopic fields or sub_images containing segments of the LDM microcirculation, the output is an adjacent single montage encompassing the entire LDM microvasculature. The developed system presents practical solutions to the problems of image registration, overlap resolution, and image segmentation, in addition, the results ...


Studies Of Mixing Processes In Gases And Effects On Combustion And Stability, Frank Paul Kozusko Jr. Jul 1995

Studies Of Mixing Processes In Gases And Effects On Combustion And Stability, Frank Paul Kozusko Jr.

Mathematics & Statistics Theses & Dissertations

Three physical models of laminar mixing of initially separated gases are studied. Two models study the effects of the mixing dynamics on the chemical reactions between the gases. The third model studies the structure and stability of a laminar mixing layer in a binary gas. The three models are:

1. Two ideal and incompressible gases representing fuel and oxidizer are initially at rest and separated across an infinite linear interface in a two dimensional system. Combustion, expected as the gases mix, will lead to a rapid rise in temperature in a localized area, i.e. ignition. The mixing of the ...


An Experiment To Measure Transport Parameters In A Saturated Heterogeneous Scaled Medium, Logan Mcinnis Apr 1995

An Experiment To Measure Transport Parameters In A Saturated Heterogeneous Scaled Medium, Logan Mcinnis

Mathematics, Engineering and Computer Science Undergraduate Theses

One of the major difficulties in groundwater research is determining an appropriate scale at which to conduct an experiment. Because of a phenomenon called the scale effect, measured values of parameters in heterogeneous media can vary with the scale of measurement. The objective of this experiment was to measure the parameters of dispersivity and velocity at different length scales, to see if the measured values would converge to a limit at some scale of measurement. A good deal of research has been conducted on the scale effect in heterogeneous media, but this phenomenon is still not totally understood. The heterogeneous ...


A Computer Model For Airfoils With Moving Surface Boundary-Layer Control, Jacob Kimball Apr 1995

A Computer Model For Airfoils With Moving Surface Boundary-Layer Control, Jacob Kimball

Mathematics, Engineering and Computer Science Undergraduate Theses

One method that is used to enhance airplane safety and performance is to use moving surfaces on wings to increase lift. A modification of the panel method is used to model airfoils which incorporate moving surface boundary-layer control. The modification is to apply a vortex sheet of constant strength over the moving portions of the airfoil. The model is demonstrated on an airfoil that has a rotating cylinder on the leading edge. The modified panel method was programmed in Mathematica (Wolfram Research Incorporated). The results generated by the Mathematica program are displayed graphically and show an increase in lift for ...


Knowledge Acquisition And Structuring By Multiple Experts In A Group Support Systems Environment, Bernard Lee Lewis Apr 1995

Knowledge Acquisition And Structuring By Multiple Experts In A Group Support Systems Environment, Bernard Lee Lewis

Engineering Management & Systems Engineering Theses & Dissertations

This study addresses the impact of Group Decision Support Systems (GDSS) on expert system development by multiple Domain Experts. Current approaches to building expert systems rely heavily on knowledge acquisition and prototyping by a Knowledge Engineer working directly with the Domain Expert. Although the complexity of knowledge domains and new organizational approaches demand the involvement of multiple experts, standard procedures limit the ability of the Knowledge Engineer to work with more than one expert at a time.

Group Decision Support Systems offer a networked computerized environment for group work activities, in which multiple experts may express their ideas concurrently and ...


Identification And Characterization Of The Iron-Zinc Intermetallics Formed In Galvanneal Steel, Richard Frederick George Grant Apr 1995

Identification And Characterization Of The Iron-Zinc Intermetallics Formed In Galvanneal Steel, Richard Frederick George Grant

Physics Theses & Dissertations

The demand to improve the corrosion resistance of steel sheet, particularly for use within the automotive industry, has led to a dramatic increase in the use of coated steels in place of cold-rolled sheet steel. Galvanneal steel results from the post annealing of the zinc-coated steel sheet, in which iron and zinc are interdiffused to form an iron-zinc alloy coating. Within this alloy coating, four main iron-zinc phases, Zeta, Delta, Gamma-1, and Gamma may be present. Manufacture of the most suitable coating requires identifying which phases form during the galvannealing process, an understanding of the properties of each phase and ...


Minimizing The Radiated Sound Power With Minimal Structural Modification , Daniel Henry Kruger Jan 1995

Minimizing The Radiated Sound Power With Minimal Structural Modification , Daniel Henry Kruger

Retrospective Theses and Dissertations

In cases where a structure's excitation cannot be altered, the sound radiation from the structure must be minimized by modifying the structure within given design constraints. This dissertation considers minimizing sound radiated by an existing structure with minimal changes to the structure itself. To accomplish this the sound power radiated by a structure was written as a function of the normal surface velocity using the boundary element method. The feasibility of reducing radiated sound power with small patches of constrained layer damping material is proved. Small patches of constrained layer damping material are placed on the structure to effectively ...


Parallel Surface Reconstruction Through Virtual Milling , Kumaran Kalyanasundaram Jan 1995

Parallel Surface Reconstruction Through Virtual Milling , Kumaran Kalyanasundaram

Retrospective Theses and Dissertations

Surface definition deals with representing a surface analytically using a finite number of parameters and with acceptable levels of error. In the past few years it has become a key discipline in Computational Fluid Dynamics (CFD). Recent advances in computers and numerical algorithms have made it possible for CFD practitioners to attempt flow solutions about complex three-dimensional geometries. The first step in this process is having a numerical representation of the shape. In many cases of interest such a representation already exists; i.e., aircraft designed on a computer. Such Computer-Aided Design (CAD) descriptions do not exist, though, for objects ...


Determining Agricultural Chemical Transport Through The Vadose Zone Using A Large Borehole Cavity , Dean Ivan Olson Jan 1995

Determining Agricultural Chemical Transport Through The Vadose Zone Using A Large Borehole Cavity , Dean Ivan Olson

Retrospective Theses and Dissertations

A large borehole cavity designed to investigate agricultural chemical transport through the vadose zone was installed at the Agronomy-Agricultural Engineering Research Center near Ames, Iowa. The system consisted of a culvert installed vertically in the soil profile with stainless steel suction lysimeters installed radially from the cavity wall. Suction lysimeters were installed at five depths in the soil profile with five replications at each depth to monitor changes in water quality in the vadose zone and below the water table. Electronic tensiometers and a data logger system were installed to continuously monitor matric potential and used to automatically collect water ...


Modeling Recession And Low Flow Characteristics Of Iowa Streams , Ahmad Ali Raaii Jan 1995

Modeling Recession And Low Flow Characteristics Of Iowa Streams , Ahmad Ali Raaii

Retrospective Theses and Dissertations

Available mean daily streamflow data from 143 gaging stations were initially analyzed to characterize recessions and low flows of Iowa streams. The period of record varies between 10 and 115 years for different stations. A computerized mathematical model was used to derive two master recession curves (MRC's)--one for winter and the other for summer--and to calculate the median storage delay factor (K med) for each individual station. These factors were used to estimate the diffusivity of the aquifer(s) contributing base flow to each stream;The MRC's can be used to forecast the general behavior of streams ...


Surface And Sub-Surface Ablation Cell Design For Remote (Robotic) Radioactive Soil Analysis Using Laser Ablation-Inductively Coupled-Atomic Emission Spectrometry/Mass Spectrometry La-Icp-Aes/Ms , Reza Bashirzadeh Jan 1995

Surface And Sub-Surface Ablation Cell Design For Remote (Robotic) Radioactive Soil Analysis Using Laser Ablation-Inductively Coupled-Atomic Emission Spectrometry/Mass Spectrometry La-Icp-Aes/Ms , Reza Bashirzadeh

Retrospective Theses and Dissertations

There are approximately 1800 uncontrollable hazardous waste sites across the United States. The Department of Energy (DOE) is responsible for cleaning up several of these sites that were contaminated as a result of producing weapon-grade nuclear fuels in different states since the 1940s. Site characterization is the first and a very critical step in the remediation program of a radioactive contaminated site. During this process, all the necessary information about location, level, and chemical composition of the contaminated sites must be collected for the clean up planning. Ames Laboratory, one of the U.S. Department of Energy sites, has adopted ...


A Predictive Model Of The Hf Noise Environment At Satellite Heights , Marisa Mccoy Jan 1995

A Predictive Model Of The Hf Noise Environment At Satellite Heights , Marisa Mccoy

Retrospective Theses and Dissertations

The radio noise background is an area of continuing research and measurement. In many cases, the background noise becomes the primary limiting factor in a communication system's sensitivity. The issue of HF (1-30 MHz) interference from terrestrial sources is especially pertinent to space-based low-frequency radio astronomy. Radio astronomy observations in the HF portion of the electromagnetic spectrum could result in new insights into astrophysical processes. However, this particular part of the spectrum is mostly inaccessible from the ground due to the effects of the Earth's ionosphere;The objective of this research is to determine to what extent terrestrial ...


Design Of Developmental Test Programs For One-Shot Systems With Two State Reliability , Mu-Yeh Huang Jan 1995

Design Of Developmental Test Programs For One-Shot Systems With Two State Reliability , Mu-Yeh Huang

Retrospective Theses and Dissertations

This dissertation considers efficient developmental testing for one-shot systems (for example, missiles) that are destroyed in testing or first normal use, where there is the possibility of "reliability growth" of the basic system design as a result of redesigns following failed developmental tests. We consider situations where the cost of redesign is negligible and there is a fixed procurement budget covering both system development and purchase, each developmental test produces either a binary (success-failure) or a continuous outcome. The analysis offered here is intended as an answer to the question "How much testing is enough?" posed by Seglie (1992) in ...


Analysis Of Nonlinear Modal Interaction And Its Effect On Control Performance In Stressed Power Systems Using Normal Forms Method , Chih-Ming Lin Jan 1995

Analysis Of Nonlinear Modal Interaction And Its Effect On Control Performance In Stressed Power Systems Using Normal Forms Method , Chih-Ming Lin

Retrospective Theses and Dissertations

In this research the nonlinear modal interaction and the effect of the interaction on the stressed power system dynamic behavior including excitation control performance are discussed. A systematic scheme based on the normal forms method for the determination of nonlinear interaction between fundamental modes and excitation control modes in a stressed power system is developed;In a stressed power system, the interarea mode phenomenon may occur under large disturbance. Recent investigations revealed that the interarea mode may be among the power system fundamental modes of oscillation associated with the nonlinear modal interaction. If there is significant interaction, the controls will ...


Effects Of Shallow Water Tables On Soil Aeration, Water Quality, And Physiological Growth Of Soybean , Tahir Sarwar Jan 1995

Effects Of Shallow Water Tables On Soil Aeration, Water Quality, And Physiological Growth Of Soybean , Tahir Sarwar

Retrospective Theses and Dissertations

This study was conducted to investigate the effects shallow water table depths on soil aeration, groundwater quality and on some physiological growth and yield parameters of soybean. The experiments were conducted in two environmentally controlled growth chambers using sixteen lysimeters. Water table (WT) treatments were established on 37 day after planting (DAP), at depths of 0.15-, 0.30-, 0.45- and 0.60-m below the soil surface. Soil aeration status was determined by measuring soil oxygen concentrations at 0.15-, 0.30-, 0.60-m depths in the lysimeters. Effects of water table depths on groundwater quality were determined by ...


Amino Acid Composition Of Soil Organic Matter And Nitrogen Transformations In Soils Under Different Management Systems , Zachary Ngewoh Senwo Jan 1995

Amino Acid Composition Of Soil Organic Matter And Nitrogen Transformations In Soils Under Different Management Systems , Zachary Ngewoh Senwo

Retrospective Theses and Dissertations

Studies of amino acid composition of soil organic matter extracted from 10 Iowa surface soils and from surface soils of two long-term rotation experiments showed that, with the exception of asparagine plus aspartic acid and glutamine plus glutamic acid, the other 13 amino acids, expressed as percentages of total amino acid extracted, were very uniform among the soils. The total amino acid extracted was significantly correlated with organic C (r = 0.79[superscript]\*\*) and clay content (r = 0.76[superscript]\*\*), but not with total N. Expressed as percentages of organic C and N in soils, the amounts extracted ranged from ...


Total System Performance Assessment Of The Proposed High Level Radioactive Waste Repository Site At Genting Island, Karimunjawa, Indonesia , Yudi Utomo Imardjoko Jan 1995

Total System Performance Assessment Of The Proposed High Level Radioactive Waste Repository Site At Genting Island, Karimunjawa, Indonesia , Yudi Utomo Imardjoko

Retrospective Theses and Dissertations

Indonesia is about to enter the nuclear era by building several nuclear power plants in the near future. Numerous issues must be addressed to evaluate the impact on the environment of high-level radioactive waste (HLRW) generated by these plants. This consideration of HLRW management must be done in a timely manner;This dissertation discusses the methodology for the Genting repository site development plan. The approach to the development of the repository is divided into three main areas, the inventory of HLRW, the barrier systems (natural and engineered), and the physical conditions of the site. The radionuclide inventory and waste form ...


Automated Image Inspection Using Wavelet Decomposition And Fuzzy Rule-Based Classifier , Zhong Zhang Jan 1995

Automated Image Inspection Using Wavelet Decomposition And Fuzzy Rule-Based Classifier , Zhong Zhang

Retrospective Theses and Dissertations

A general purpose image inspecting system has been developed for automatic flaw detection in industrial applications. The system has a general purpose image understanding architecture that performs local feature extraction and supervised classification. Local features of an image are extracted from the compactly supported wavelet transform of the image. The features extracted from the wavelet transform provide local harmonic analysis and multi-resolution representation of the image. Image segmentation is achieved by classifying image pixels based on features extracted within a local area near each pixel. The supervised classifier used in the segmentation process is a fuzzy rule-based classifier which is ...


Measuring And Modeling Alachlor Dissipation In Soil , Dee Anna Jo Weed Jan 1995

Measuring And Modeling Alachlor Dissipation In Soil , Dee Anna Jo Weed

Retrospective Theses and Dissertations

Field and laboratory experiments evaluated the overall dissipation of alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide) and the effect of no-till and chisel-plow tillages on alachlor leaching and dissipation. In the top 30-cm layer of field soil, the time to 50% dissipation (half-life) was 2 to 3 d, and the time to 90% dissipation ranged from 17 to 30 d. In no-till soil, alachlor dissipated slightly faster, and more was transported into the 10-to-30-cm soil layer. The tillage effect depended on weather that favored movement into and dissipation within the soil, rather than dissipation on plant residues and the soil ...


Genetic-Based Unit Commitment Algorithm , Timothy Trent Maifeld Jan 1995

Genetic-Based Unit Commitment Algorithm , Timothy Trent Maifeld

Retrospective Theses and Dissertations

The National Energy Policy Act of 1992 allows open access to transmission lines. The electric utility industry is in the transition from operating in a monopolistic environment to one that is less regulated. For an electric utility to operate in this new environment, a new algorithm is needed to optimally schedule generating units in the needed response time of an electric power broker. Past methods of unit commitment scheduling are either too computationally slow or do not produce optimal unit commitment schedules. Unit commitment scheduling is the problem of determining the optimal set of generating units within a power system ...


Oxidation And Creep Behavior Of Mo5si3 Based Materials , Mitchell Karl Meyer Jan 1995

Oxidation And Creep Behavior Of Mo5si3 Based Materials , Mitchell Karl Meyer

Retrospective Theses and Dissertations

Mo[subscript]5 Si[subscript]3 shows promise as a high temperature creep resistant material. The high temperature oxidation resistance of Mo[subscript]5 Si[subscript]3 has been found to be poor, however, limiting its use in oxidizing atmospheres. Mo [subscript]5Si[subscript]3 exhibits mass loss during oxidation at 800°-1200° C due to volatilization of molybdenum oxide, indicating that the silica scale that forms does not provide a passivating layer. Catastrophic 'pest' oxidation occurs at 800° C. The oxidation rate at 1200° C is on the order of 10[superscript]3 mg cm[superscript]-2 hr[superscript ...


Preparation And Characterization Of B2s3-Based Chalcogenide Glasses , Jaephil Cho Jan 1995

Preparation And Characterization Of B2s3-Based Chalcogenide Glasses , Jaephil Cho

Retrospective Theses and Dissertations

The discovery of the fast ion conducting B[subscript]2S[subscript]3-based glasses has been one of the most significant development in the field of solid electrolytes. Considerable experimental studies have been done to maximize conductivities and chemical stabilities of these glass systems. Recently, the study of the structure and properties of these glasses compared to their oxide analog has become important;The IR spectra of M[subscript]2S + B[subscript]2S[subscript]3 (M = Li, K, Rb and Cs) and MS + B[subscript]2S[subscript]3 (M = Sr and Ba) thioborate glasses have shown the monotonic increase in tetrahedral ...


Increasing The Efficiency Of A Piezoelectric Aluminum Nitride Microstrip Resonator By Utilizing High Temperature Superconductors , Edward David Goff Jan 1995

Increasing The Efficiency Of A Piezoelectric Aluminum Nitride Microstrip Resonator By Utilizing High Temperature Superconductors , Edward David Goff

Retrospective Theses and Dissertations

High temperature superconductors have potential applications in the field of microwave devices and circuits. To utilize these materials in such a way as to increase the efficiency of these microwave devices would be beneficial for high efficiency/low noise applications. This dissertation accomplishes the following goals: (1) The design and fabrication of an initial device that increases the quality factor, Q, and therefore the efficiency of a high frequency thin film resonator which uses superconducting metal as the device's electrode, (2) the measurement and characterization of this device, (3) the theoretical calculation and predicted performance of this device, and ...


Electronic And Photonic Devices: Experimental Investigations Of Hydrogenated Amorphous Silicon Substrate N+/I/P+ Solar Cell And Fundamental Properties Of Quantum Wells With Cylindrical Geometry And Applications To Electronics And Photonics , Er-Xuan Ping Jan 1995

Electronic And Photonic Devices: Experimental Investigations Of Hydrogenated Amorphous Silicon Substrate N+/I/P+ Solar Cell And Fundamental Properties Of Quantum Wells With Cylindrical Geometry And Applications To Electronics And Photonics , Er-Xuan Ping

Retrospective Theses and Dissertations

This thesis consists of two different parts: (I) experimental investigations of hydrogenated amorphous silicon substrate n[superscript]+/i/p[superscript]+ solar cells and, (II) fundamental properties of quantum wells with cylindrical geometry and applications to electronics and photonics;Part I. The substrate structural n[superscript]+/i/p[superscript]+ solar cells based on a-Si:H materials are fabricated by a radio frequency (RF) triode geometric plasma enhanced chemical vapor deposition (PECVD) system. The solar cells have been electrically and optically tested. Two different substrates, tin-oxide coated glass and stainless steel foil, are used. An RF magnetron sputtering system is used to ...


A Continuous Media Transport Protocol , Paul Michael Freeman Jan 1995

A Continuous Media Transport Protocol , Paul Michael Freeman

Retrospective Theses and Dissertations

A protocol for the transmission of digitized audio and video data must schedule data transmission such that each audio or video sample is available in the receiver's buffer by its play-out deadline without overflowing the allotted buffer space at the receiver. While traditional data communication protocols provide error-free data transmission through the use of time-outs and retransmissions, the unbounded number of retransmissions that a packet may suffer results in an unboundable network transmission delay. Thus, such protocols are not appropriate for the real-time transmission of digitized audio and video data;This dissertation examines the network environments likely to be ...


Metallization Of Polyimide Films To Enhance Dimensional Stability And To Achieve Reflective And Conductive Surfaces, David Scott Thompson Jan 1995

Metallization Of Polyimide Films To Enhance Dimensional Stability And To Achieve Reflective And Conductive Surfaces, David Scott Thompson

Dissertations, Theses, and Masters Projects

No abstract provided.


Characterization Of Nylon-11 Degradation, Leslie Christian Mccullough Jan 1995

Characterization Of Nylon-11 Degradation, Leslie Christian Mccullough

Dissertations, Theses, and Masters Projects

No abstract provided.


Characterization Of Pr500 For Use In Resin Transfer Molding, Rhonda Michelle Barksdale Jan 1995

Characterization Of Pr500 For Use In Resin Transfer Molding, Rhonda Michelle Barksdale

Dissertations, Theses, and Masters Projects

No abstract provided.