Digital Commons Network^™

Investigation Of The Electric Field In The Vicinity Of A Water Drop Adhering To A Conductor, Jamnarn Hokierti

Masters Theses

"Electric field calculations in the vicinity of a conductor above ground are developed with constraints on the distance from the conductor for which the electric field equations can be applied for practical applications. The electric field in the vicinity of a small water drop adhering to the conductor has been calculated. Application of this electric field in the vicinity of the water drop has been used to compute the apparent surface charges and also the forces on the small water drop surface. Methods for the calculation of space charge due to ionization on the water drop has been suggested"--Abstract, page …

The Investigation Of Video Sensitivity And Data Processing Errors Encountered In An Airborne Receiver, James Lee Hamilton

Masters Theses

"The investigation of video sensitivity and both biphase demodulation and Doppler shift processing errors is performed. The effect of pass band ripple on the noise bandwidth of two pole filters is developed. The effect of feedback on the effective noise figure of a high gain IF (Intermediate Frequency) amplifier is investigated and discussed. An analysis of a limiting amplifier-biphase demodulator circuit is attempted. A computer simulation of this same circuit is also performed and the results are compared to measurements taken in the laboratory. With respect to multipath corrupted input signals, a differential phase shift keyed biphase demodulator is shown …

A Study Of Pollution Abatement From The F-15 Jet Engine Test Stand, Gary Joseph Fennewald

Masters Theses

"The pollutants emitted from jet engine test stands are carbon particles, unburned hydrocarbons, carbon monoxide, and the oxides of nitrogen. This work is a study of various ways of removing these pollutants from the test stand exhaust. The methods investigated include absorption, adsorption, electrostatic precipitation, filtration, catalytic reduction and oxidation, and thermal oxidation.

For abatement of nitrogen oxides, none of the present methods is considered to provide adequate technical reliability to proceed with an installation at this time. Each of the methods for removal of nitrogen oxides has high capital and operating cost; and, in many cases, secondary pollution problems …

Calculation Of The Neutron Flux In The Side Regions Of The Prestressed Concrete Reactor Vessel Of A High Temperature Gas Cooled Reactor, Richard Robert Kent Jr.

Masters Theses

"Neutron flux in the side regions of the High Temperature Gas Cooled Reactor's (HTGR) Prestressed Concrete Reactor Vessel (PCRV) was determined using the Monte Carlo method. One quarter of the PCRV was modeled, with all major structures inside it, e.g. steam generator, auxiliary cooling loop, etc. imaged at their exact position and size. Initial neutron energies range from .001 eV to 3 MeV. Three neutron interactions were considered: absorbtion, elastic scattering, and inelastic scattering.

The flux was calculated for two different PCRV temperatures, 155° F and 647° F. The thermal flux showed a minor increase at the higher temperature. In …

An Investigation Of The Vertical Distribution Of Sulfur Forms In Surface Mine Spoils, Henry County, Missouri, Walter Carter Von Demfange Jr.

Masters Theses

"Samples of material in the spoil banks left by surface coal mining operations in Henry County Missouri were taken from various depths and preserved to prevent further oxidation of the pyrite in the samples. Quantitative determinations were then made for sulfate and sulfide sulfur. It was shown that near the surface the sulfide sulfur concentrations were much lower than those at greater depth while sulfate concentrations were higher near the surface than at depth. Since this is probably the effect of years of oxidation of the pyrite, it can be used to show at what depth the pyrite is being …

Possible Damage Mechanism In Dresden 2 Class Boiling Water Reactor Fuel, Donald Lee Moffett

Masters Theses

"A thermal hydraulic analysis of a typical hot channel of a Dresden 2 class boiling water reactor is studied for possible severe local overheating. The COBRA-II thermal hydraulic analysis code is modified to include critical heat flux calculations for each subchannel. The effects of flow distribution, inlet mass velocity variations, dimensional tolerances, enrichment variations, and input parameters are examined in detail. Bulk channel results are in good agreement with the published data, but the assembly wall side of the corner fuel rod has a minimum critical heat flux ratio of less than unity for a number of the situations examined. …

A Study Of The Feasibility In Obtaining The Kinetics Of Various Ordering Phenomena Of The Iron Aluminum System Utilizing The Mössbauer Effect, Lloyd Rollan Chapman

Masters Theses

"The determination of the kinetics of ordering for various ordering phenomena of the Iron-Aluminum system utilizing exclusively the Mössbauer effect technique is shown to be infeasible for all but a highly restrictive consideration from experimental as well as theoretical evidence. Also, the possible use of the Mössbauer effect for the analysis of other ordered systems is discussed.

An alternative method for the acquisition of the needed information utilizing diffraction and Mossbauer techniques is presented recognizing the need for a computer fitting analysis of the complex Mössbauer effect spectra. However, at this stage of investigation, no experimental work has been performed …

A Review Of Directed Graphs As Applied To Computors, Paul D. Stigall, Ömür Tasar

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Transient Thermal Stresses In A Sphere By Local Heating, J. B. Cheung, T. S. Chen, K. Thirumalai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of transient thermal stresses in a solid, elastic, homogeneous, and isotropic sphere is solved for uniform and nonuniform, local surface heating. The temperature solutions are obtained by using separation of variables and integral transformation. The corresponding thermal stresses are derived by superposing a particular displacement potential function on Boussinesq solutions. Numerical solutions for two particular cases of localized heating of a typical brittle spherical solid have been obtained and presented. The results indicate a tensile stress concentration in the interior of the solid below the heated zone. © 1974 by ASME.

Vibration Characteristics Of Free Thin Cylindrical Shells, Floyd M. Cunningham, D. E. Leanhardt

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper considers the flexural vibrations of free thin circular cylinders. A frequency equation is derived using free-free characteristic beam functions to represent the variation of mid-surface shell displacement components, u, v and w, with respect to the axial direction. Timoshenko strain-displacement relations for thin cylinders are used to determine elastic vibratory strain energy. Energy methods are applied to obtain the frequency equation and associated amplitude ratios for each of its roots. This energy solution is checked experimentally using a vibration exciter and numerically using the SABOR IV finite element program. With minor modification, the frequency equation conforms to the …

Performance Comparison Of Techniques For Obtaining Stereo Radar Images, George L. Bair, Gordon E. Carlson

Electrical and Computer Engineering Faculty Research & Creative Works

The performance of three stereo radar techniques is compared with respect to both theoretical performance and performance in the presence of errors. The three techniques are: an improved single flight technique, a previously proposed single flight technique, and a two flight technique. Theoretical data for comparison of image parameters affecting performance have been generated with computer simulations of the imaging geometries for the techniques. The comparison shows that the improved technique will have images with greater similarity resulting in improved stereo viewability and measurability. Computer simulations have also been used to generate sensitivities of computed terrain point coordinates to system …

Equalization Of Qpsk Data Transmission In Specular Multipath, Rodger E. Ziemer, C. R. Ryan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper gives performance results for transversal-filter equalization of Quadri phase phase-shift-keyed (QPSK) signals with two-component multipath and demodulator phase error. An analytical expression for optimum, minimum mean-square-error tap weights in terms of the multipath and signal parameters is given. Probability of error results for no equalization and equalization with adaptive decision-feedback tap-weight adjustment are compared. The results show that significant improvement can be obtained with relatively simple equalizer structures. Copyright © 1974 by The Institute of Electrical and Electronics Engineers, Inc.

Evaluating The Membrane Fecal Coliform Test By Using Escherichia Coli As The Indicator Organism, James B. Hufham

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The fecal coliform membrane filter method (MFC) currently used in water pollution analysis was evaluated by using two strains of E. coli, a known fecal coliform, as th indicator organism. A large relative error in the results obtained with this method was found to be dependent upon the brand of membrane filter employed, the medium, and the temperature of incubation. MFC densities varied between 10 and 60% of the densities determined by means of total bacteria counts and total coliform counts performed at 35°C. Due to the large relative error encountered, the MFC method cannot be recommended as an analytical …

Field Emission Of Boron On Tungsten, P. D. Ownby, Thomas A. Flaim

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

A Mass Spectrometric Study Of Positive Ions Produced In An Experimental Diode, L. A. Addington, Gordon Lewis

Materials Science and Engineering Faculty Research & Creative Works

A simple diode ion source has been developed for direct observation in a mass spectrometer of the positive ions created in an operating diode. The ionic species accelerated toward the cathode were identified. The shape of the peak displayed in the spectrum is related to the region of the diode in which the ions were formed. Variation of experimental parameters, including the composition of the background gases, indicated that the characteristic shapes of the peaks can be related to space charge in the diode. This is complicated by the tendency of some of the species to fragment and further work …

Air Breakdown In A Radial-Mode Focusing Element, Lee W. Casperson, Mohammad Shabbir Shekhani

Electrical and Computer Engineering Faculty Publications and Presentations

A new radial focusing device is described that condenses an incident laser beam to an extremely intense and uniformly illuminated focal spot. The focal region is useful for many applications. When used with a 10.6-µm CO₂ TEA laser source, a disk-shaped air-breakdown spark results, and the properties of this spark have been investigated.

Kalman Filter Equalization For Qpsk Communications, Tze-Shen Lee

Doctoral Dissertations

"The discrete complex Kalman filter is considered as an equalizer for quadrature phase shift keyed (QPSK) systems in the presence of additive noise and intersymbol interference (ISI). For a known linear time-invariant channel with finite duration impulse response, the finite n-dimension complex Kalman filter equalizer is able to reduce the degradation caused by ISI. When the channel is unknown, an adaptive Kalman equalizer is used in which the channel complex tap gains are estimated by decision feedback. A two component multipath channel QPSK system is used as an example. Using the Chernoff upper bound to calculate the error probabilities, the …

Surface Elastic Waves In Piezoelectric Semiconductors And Layered Media, Yu-Pin Han

Doctoral Dissertations

"The primary interest of this investigation is to understand the surface elastic wave properties in piezoelectric semiconductors and layered media. Generalized piezoelectric wave equations in piezoelectric semiconductors and layered media are derived. Systems considered are the piezoelectric semiconductor, the two layer piezoelectric insulator-semiconductor, the three layer piezoelectric insulator- gap-semiconductor and the four layer piezoelectric insulator-gap-semiconductor-dielectric substrate. The eigenwave expansion and the iteration methods in the complex domain are used to solve the problems. Mathematically, it represents a solution of the eigenvalue boundary value problem which involves iteration of functions in the complex domain. Solutions obtained are eigenvalues and eigenvectors which …

Anionic Polymerization Of A Series Of Cyclocarbosiloxanes, William W. Knickmeyer

Doctoral Dissertations

"A study has been made on the anionic polymerization of a series of cyclocarbosiloxanes of the type: [IMAGE] where n was varied from 2 to 8. The polymerization reaction in benzene, was initiated using cesium trihexyl silanolate, a unique organic soluble liquid catalysts. Benzene served as both a solvent and to shift the position of the NMR SiCH₃ polymer peak away from the monomer peak making it feasible to follow the kinetics on a Varian EM-360 Nuclear Magnetic Resonance Spectrometer. Hexamethylphosphoramide (HMPA) was used as a promoter to solvate the initiator ions and thus increasing the polymerization rate. It …

Towards A Design Of Hmo, An Integrated Hardware Microcode Optimizer, James Oliver Bondi

Doctoral Dissertations

"This paper discusses an algorithm for optimizing the density and parallelism of microcoded routines in micro-programmable machines. Besides presenting the algorithm itself, this research also analyzes the algorithm's uses, design integration problems, architectural requirements, and adaptability to conventional machine characteristics. Even though the paper proposes a hardware implementation of the algorithm, the algorithm is viewed as an integral part of the entire microcode generation and usage process, from initial high-level input into a software microcode compiler down to machine-level execution of the resultant microcode on the host machine. It is believed that, by removing much of the traditionally time-consuming and …

The Morphology Of Cellular Precipitation In Magnesium Rich Magnesium-Aluminum Alloys, Jyong Shi Cho

Doctoral Dissertations

"The morphology of cellular precipitation in a Mg-9wt. %AI alloy has been investigated by light and electron microscopy. A study of the early stages of the cellular precipitation process indicated that cellular precipitate structure forms in Mg-Al alloys by Fournelle and Clark mechanism. "Replacive" motion indicative of the Tu and Turnbull mechanism for cellular precipitation was not seen"--Abstract, page 1.

An Analytical And Experimental Study Of The Dynamic Response Of A Press, Woosoon Bai

Doctoral Dissertations

"This dissertation presents a simplified mathematical model and computer simulation of the vertical motion of a press. The model is verified by comparing simulation results with actual field measurements.

Using this model, the computer simulation is then extended to study the dynamic response of a bolted press, one with loosened anchor bolts, and one which is isolated. Press performance, in terms of acceleration of the press, velocity of its foundation, and forces transmitted to the foundation, is analyzed in relation to the foundation mass and the stiffness of the isolators, where applicable. Comparative performances of the presses secured by the …

Solid Transformations And Premelting Phenomena In Fluorite Structures And The System Srcl₂Bacl₂, Damri Sukhotanang

Doctoral Dissertations

"Thermal expansion and phase transformations in CaF₂, BaF₂, SrCl₂, and BaCl₂ were studied by high temperature x-ray diffractometry, differential thermal analysis, and thermodilatometric analysis. Thermal expansion characteristics of CaF₂, BaF₂ and SrCl₂ are very similar. The structures expand normally at lower temperatures and depart substantially from linearity at higher temperatures, because of formation of defects and disordering of anions. At high temperatures CaF₂ and BaF₂ react with water vapor, even at low humidities, forming oxides and emitting HF, leading to difficulty in observation of phase transformations. SrCl …

In Vitro Studies Of Lipid Uptake By Medical Grade Silicone Rubbers Used For Heart Valve Balls, Shu Hua Wu

Doctoral Dissertations

"Various chemical and physical aspects of high lipid absorption by medical grade silicone rubber and the dynamic mechanical properties of lipid-rubber systems were studied in order to provide an insight into the problem of 'variance' of these materials when subjected to 'in vitro' and 'in vivo' environments. Wide variations of post cure procedures of the silicone rubber were studied. Different post cures did not appreciably affect the mechanical properties of the silicone rubber. Mass transfer studies demonstrated that the diffusion of linolenic acid into a silicone rubber slab is a purely physical diffusion process (D = 3.2 x 10^{-3 …}

A Finite Element Method For Three-Dimensional Analysis Of Metal Forming, Nguyen Don Phu

Doctoral Dissertations

"The importance of metal forming by extrusion was reviewed. A Finite Element Approach was developed to analyze extrusion processes. A brick type linear element and the Upper Bound theorem were used to analyze the extrusion of a cylindrical billet into a square cross-section prism. A minimization technique for a non-linear functional with linear constraints was developed. Different types of boundary conditions were also formulated. A frictionless extrusion was simulated using the computer program developed. Velocity profiles at different sections of the deforming solid were obtained and an average extrusion pressure was predicted for a given area reduction ratio.

Extrusions from …

Parameter Identification Of Nonuniform Distributed Rc Networks, Roger Allen Hayes

Doctoral Dissertations

"The problem of the unique parameter identification of nonuniform distributed RC networks is addressed in this dissertation. Previous literature provides for the equivalence of distributed networks with respect to the terminal characteristics. Therefore, the question is whether unique parameter identification is even possible. This work settles that question by presenting the sufficient conditions to insure a unique solution to the parameter identification problem. One theorem requires the knowledge of a driving-point impedance, the knowledge of the physical length, and the constraint that the r(x)c(x) product remains constant to insure uniqueness of the parameters r(x) and c(x). Relaxation of the r(x)c(x) …

Removal Of Nutrients By Sorption On Activated Alumina, Checkman Michael Yue

Doctoral Dissertations

"The nutrient enrichment of surface, primarily impounded, water and the associated problems of accelerated eutrophication and prolific algal growth have become a nationwide concern. Phosphorus and nitrogen are considered to be the key elements in abating eutrophication and are contributed from many sources, natural and manmade; prominent among these is the discharge of domestic and industrial wastes.

The purpose of this study was to evaluate the removal of nutrients, primarily phosphorus and nitrogen, with activated alumina using a continuous-flow pilot plant system. Specific objectives were the: development and construction of appropriate bench and field-scale pilot plant units utilizing the rapid …

Transition Boiling Of Normal Pentane From A Horizontal Flat Gold Surface, Ronald M. Canon

Doctoral Dissertations

"The characteristic boiling curve for Normal Pentane was determined at 1 atmosphere pressure with particular attention devoted to the transition boiling region. The heat transfer surface was a horizontal, gold-plated, copper disc.

Stability analysis was employed to demonstrate why previous investigators have had only limited success in collecting data in the transition region and to provide a valid basis for equipment designed to operate in this region.

A method of predicting the transition region boiling curve from the nucleate curve and the Liedenfrost point is presented. The method was found to predict the transition boiling of Normal Pentane, Freon 12, …

Structural Behavior Of Cold-Formed Steel Members Made Of Thick Sheets And Plates, Ai-Shen Liu

Doctoral Dissertations

"It is well-known that the current AlSI Specification for the design of cold-formed steel structural members has been developed mainly for thin steel sections. In order to extend the applicability of the specification for the design of cold-formed steel members thicker than 1/4 in., both analytical and experimental investigations have recently been conducted with special emphases on the effects of cold work on the mechanical properties of corners and the strength of bolted connections.

For the effects of cold work, previous investigations have shown that the phenomena of strain hardening and strain aging are main factors which affect the mechanical …

Direct And Inverse Heat Conduction In Rock Materials Using The Finite Element Method, Vernon Dale Allen

Doctoral Dissertations

"A finite element method is presented for solution of direct and inverse heat conduction problems in rock materials. Finite element programs for direct and inverse heat conduction problems were developed and demonstrated. Flow charts are given for the finite element programs.

The direct finite element heat conduction program changes material properties with temperature to approximate the temperature dependent properties of rock materials. An example problem was solved by the finite element method and also using Kirchoff's transformation. The finite element solution compared quite well with the Kirchoff transformation solution.

The inverse method utilizes the direct finite element heat conduction program …