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A Heuristic Algorithm For Determining A Constructive Suboptimal Solution To The Combinatorial Problem Of Facility Allocation, Harry Kerry Edwards

Doctoral Dissertations

"The major problem in plant layout is to determine the most economical relative location of facilities. There are two distinct types of suboptimal solutions to this combinatorial problem: construction and improvement. The writer has developed Modular Allocation Technique (MAT) which is the first useful construction suboptimal technique. The MAT general algorithm, a theorem relating the MAT solution to the optimal solution and an example problem are given. A computer program has been written that will apply MAT to the allocation problem for a maximum of 40 facilities. Results are given to demonstrate how MAT solutions may be used as initial …

A Study Of The Anodic Oxidation Of 1, 3-Butadiene On Platinum And Gold Electrodes, Arun Kumar Agrawal

Doctoral Dissertations

"The anodic oxidation of 1,3-butadiene on Pt and Au electrodes was studied at 70°C in solutions of H₂SO₄, K₂SO₄, K₂CO₃, and KOH with pH's ranging from 0.35 to 12.5. Reaction rates (current) were measured as a function of potential, pH, temperature, and butadiene partial pressure. A transition region (apparently a shift in the rate determining step) in case of Pt was observed in the Tafel plots. The coulombic efficiencies of oxidation to CO₂ were 85 percent in 1 N H₂SO₄ on Pt, 93 percent in 1 N KOH on Pt, and 72 percent in 1 N KOH on Au"--Abstract, Page …

Absolute Excitation Cross Sections Of He⁺ In 20-100 Kev He⁺-He Collisions Using Energy-Loss Spectrometry, Donald Roy Schoonover

Doctoral Dissertations

"Application of positive-ion energy-loss spectrometry has been extended to include experimental determination of absolute excitation cross sections of ground state helium ions. Helium ion-atom collisions were studied for impact energies ranging between 20-100 keV, in 10 keV intervals. The data were taken with an apparatus resolution between 0.6-o.8 eV FWHM. Cross sections for transitions from ground state to the second and third principal quantum levels of the ion plotted as a function of impact energy were still rapidly increasing at 100 keV. The cross sections at this energy were 1.64(± 0.28) x 10⁻¹⁸cm² for He⁺(l²s_1/2) -> He⁺(n = …

Discrimination Of Signal And Noise Events On Seismic Recordings By Linear Threshold Estimation Theory, David Nuse Peacock

Doctoral Dissertations

"The object of this study is the investigation of a linear threshold element technique for identifying surface multiples on a single seismic trace. Traces of seismic events were generated which contained primaries, surface multiples, and various levels of Gaussian random noise. Since it was necessary to separate the events as much as possible, the traces were subjected to pulse-compression deconvolution processing prior to LTE analysis. Mean frequency, peak frequency, amplitude spectrum variance, periodicity, and polarity were employed as pattern parameters. A set of weights was found that would maximize the moment of inertia of the S line distribution of the …

The Iron-Holmium Binary System And Related Magnetic Properties, Gerald J. Roe

Doctoral Dissertations

"The iron-holmium phase diagram was investigated to determine the alloying behavior of these two metals and to determine the magnetic properties of some of the iron-holmium alloys which formed intermediate phases. The iron-holmium binary system was determined by three experimental techniques, differential thermal analysis (DTA), x-ray diffraction, and metallography. A phase diagram with three eutectic points and four intermediate phases was constructed from the experimental data. The two phases, Ho₆Fe₂₃ and Ho₂Fe₁₇, melted congruently at 1322⁰C and 1343⁰C respectively. HoFe₂ and HoFe₃ melted incongruently at 1288⁰C and 1293⁰C respectively. Neutron diffraction investigations were made on the intermediate phases Ho₆Fe₂₃ and …

Investigation Of Auroral Phenomena By Sounding Rocket, Wentworth Edwards Potter

Doctoral Dissertations

No abstract provided.

Longitudinal Optical Phonon-Plasmon Coupling In Ionic Semiconductors, Thomas Joseph Mcmahon

Doctoral Dissertations

"The coupling of free carriers and lattice vibrational modes is studied in CdS and InSb by room temperature far infrared reflectance measurements. When the free carrier concentration is such that the plasma frequency is at or near the longitudinal optical mode frequency it is shown that while the transverse modes remain fixed, the longitudinal modes mix with the plasma mode and are shifted in a manner similar to that described by Varga in 1965. Using the dielectric function for the coupled system permits the determination of electron effective masses by reflectance measurements with lattice effects excluded. This method allows one …

A Crystallization Study Of A Tetrasilicic Fluormica Glass, William H. Daniels

Doctoral Dissertations

"The transformation of a synthetic mica composition K₂Mg₅Si₈O₂₀F₄ from amorphous to crystalline structure was studied isothermally at selected temperatures from 560°C to 1150°C. thermal changes associated with the transformation were followed by differential thermal analysis techniques. Structural changes promoted by the isothermal treatments were observed by density measurements, Debye-Scherrer X-ray diffraction techniques, electron replication microscopy, and electron scanning microscopy. Isothermal treatment at 450°C for 9 hours produces structural ordering in quenched K₂Mg₅Si₈O₂₀F₄ glass. Fluorine exerts a significant influence on the transformation temperature; decreasing amounts of fluorine producing increasing transformation temperatures. The crystallizing phase rapidly attains a limiting particle size and …

A Method For Determining Transient Stability In Power Systems, Charles A. Gross

Doctoral Dissertations

"Given a three phase ac power system consisting of synchronous alternators interconnected by transmission lines and other items of electrical transmission equipment, a method is presented which determines the stability of the system when subjected to a three phase symmetrical fault, and to the subsequent clearing of the fault. It is inherent in the method that an estimation of system stability, assuming an instantaneous clearing of the fault, is available. The critical clearing time is therefore determined. The effect of a speed control loop on the system's largest machine is investigated. The method is applied to two, three, four, and …

Calorimetry Of Room Temperature Deformed Copper, George Juri Filatovs

Doctoral Dissertations

"An adiabatic anisothermal differential calorimeter for the study of room temperature deformed 99.999% pure copper has been constructed. An annealed and a deformed specimen were heated at a constant rate in adiabatic surroundings and the differences in energy released between samples was obtained. The control circuits were automatic. Deformation was by elongation ranging from 12 to 40%, and the corresponding energy found was from 1.9 to 5.3 calories/gram-atom. No recovery energy was found. The results obtained generally agree with published results and, in particular, verify Gordon's isothermal annealing results. It is proposed that the criteria for the presence of recovery …

Mass And Heat Transfer Through Nonwettable Porous Membranes, Chung-Liang Yeh

Doctoral Dissertations

"Evaporation of water through nonwettable porous membranes has been studied under various pressures with various membrane thicknesses. The results of previous investigations at 1 atmosphere have been correlated into one equation for mass transfer resistance which has also been found to fit approximately new data obtained of 1.5, 2, and 3 atmospheres in this investigation. In the new data fluxes varied from 0.064 to 0.691 lb./ft.²/hr. through glass fiber-Teflon membrane from 0.02 to 0.08 inch in thickness. Temperatures ranged for 80 to 260°F. A more theoretical equation has been developed to explain variations from the equations based on 1 atmosphere …

Models For The Pn Diode And The Npn And Pnp Transistor For Use In Computer Aided Design And Analysis Programs, Glenn Ronald Case

Doctoral Dissertations

"This work is concerned with the problem of developing suitable mathematical representations for the pn junction diode and npn and pnp transistors for use in computer aided design and analysis programs. The Ebers-Moll model as used in the Net-1 program has been considerably improved, particularly regarding base resistance prediction, prediction of high forward current behavior, and the addition of reverse breakdown terms. The resulting models show substantial improvement in representation of d-c and transient characteristics. Some improvement in a-c characteristics has also been obtained. Methods of obtaining parameters for the new model and several of the present models, given measured …

A Finite Element Method For Geometrically Nonlinear Large Displacement Problems In Thin, Elastic Plates And Shells, Ronald August Melliere

Doctoral Dissertations

"A finite element method is presented for geometrically nonlinear large displacement problems in thin, elastic plates and shells of arbitrary shape and boundary conditions subject to externally applied concentrated or distributed loading. The initially flat plate or curved shell is idealized as an assemblage of flat, triangular plate, finite elements representing both membrane and flexural properties. The 'geometrical' stiffness of the resulting eighteen degree-of-freedom triangular element is derived from a purely geometrical standpoint. This stiffness in conjunction with the standard small displacement 'elastic' stiffness is used in the linear-incremental approach to obtain numerical solutions to the large displacement problem. Only …

Improvement In Target Detection With A Frequency Agile Pulsed Non-Coherent Radar, Kenneth Lee Horn

Doctoral Dissertations

"Frequency agile tracking radars have received considerable attention in the literature. Frequency agility is useful in reducing target scintillations, thereby reducing tracking errors under certain conditions. However, little attention has been devoted to the improvement that can be expected in target detection with a frequency agile radar. In the past, complete pulse-to-pulse decorrelation of the target returns has been assumed for all of the analyses concerning target detection with frequency agile radars. This assumption always implies a transmitter with a large bandwidth.

This dissertation analyses a pulsed non-coherent frequency agile radar applied to Swerling's Case I target. The target model …

Grain Boundary Self-Diffusion In Sodium Chloride, Kenneth Ray Riggs

Doctoral Dissertations

"The diffusion of ²²sodium and ³⁶chlorine along tilt and twist grain boundaries in pure and calcium chloride doped sodium chloride bicrystals was investigated. No enhanced diffusion of ²²sodium along the grain boundaries was observed. Between 400°C and 500°C the chlorine grain boundary diffusion parameter, D'Δ, is described by D'Δ = (D'Δ)₀exp (-Q_b/kT), where (D'Δ)₀ is approximately 10⁻⁷ cm³/sec and Qb is 1.15 ± .30 eV. The grain boundary angle, the grain boundary character (tilt or twist), and the calcium chloride concentration appear to have no pronounced effect upon the observed chlorine grain boundary diffusion. The ionic movement …

A Study Of The Anodic Oxidation Of Acetylene On Platinum-Gold Alloys, Christopher Kuo-Chieh Wu

Doctoral Dissertations

"The anodic oxidation of acetylene on Pt-Au alloys of four compositions (80-20, 60-40, 40-60, and 20-80 Pt-Au) was studied at 80°C in solutions of constant pH and unit normality. Currents were measured as a function of potential and partial pressure of acetylene. The effects of temperature on current in 1 N H₂SO₄ and 1 N NaOH and the coulombic efficiencies for CO₂ production were determined. The experimental results indicated that the alloys can be classified into three groups, Pt-rich, Au-rich, and intermediate compositions. A transition region (change of the mechanism) was found for the Au-rich alloys. The oxidation can be …

Dynamic Response Of Circular Plates To Transient And Harmonic Transverse Loads Including The Effect Of Transverse Shear And Rotary Inertia, Perakatte Joseph George

Doctoral Dissertations

"Using an improved theory of plate vibration suggested by R. D. Mindlin which takes into account the effects of transverse shear and rotary inertia, free and forced transverse vibrations of uniform circular plates are studied and the results compared with those obtained using the classical theory of plate vibration. The governing equations are developed in polar coordinates using the equations of elasticity. Frequency equations for axisymmetric and antisymmetric vibrations are derived for solid circular plates under different boundary conditions and for an annular plate rigidly mounted on a shaft. The response of plates to different types of rapidly applied axisymmetric …

A Five Parameter Study Of Spherical Transient Waves In A Generalized Voigt Model, Liang-Juan Tsay

Doctoral Dissertations

"Transient spherical waves in a generalized Voigt model were investigated in this study. Both Laplace and fourier transform solutions of the spherical wave equation for a generalized Voigt model were obtained by means of the correspondence principle. Laplace transform solutions were inverted numerically into the domain for the study of the characteristics of the wave forms, and Fourier transform solutions were utilized for the analysis of frequency dependency attenuation in the models. Generalized Voigt models A and B in which a dashpot is connected in series with spring and dashpot components were unable to represent a solid which would simulate …

Analysis Of The Traveling-Wave Transistor, Vernon Ray Stanley

Doctoral Dissertations

"Transmission lines containing independent and dependent distributed sources are considered and the transfer matrices of various active distributed lines are derived. A method is discussed by which a lossy line can be made lossless by the appropriate choice of distributed sources. A steady-state analysis of the uniform traveling wave transistor is given. Considering the device as an active four port network, the transfer matrix is found in closed form and the power gain, output voltage, and input impedance are found. A computer program is written and the frequency response is given for various values of line parameters and terminations. Finally, …

Diffusion Of Iron And Cobalt In Nickel Single Crystals, Charles Frederick Heuer

Doctoral Dissertations

"Diffusion coefficients of iron-59 in nickel have been determined in the temperature range 815°C to 1200°C. The temperature dependence can be represented by an Arrhenius type relationship,...The effect of the isotopic mass on the diffusion coefficient of cobalt in nickel has also been investigated. The isotope effect parameter, E, was found to vary from .26 to .84 over the temperature range 970.5°C to 1200°C. Both results are consistent with the single vacancy mechanism of diffusion. No evidence of divacancy contributions to the mass transport has been found"--Abstract, Page i.

Microwave Propagation Through Isotropic Inhomogeneous Photoconductive Media, Thomas Van Doren

Doctoral Dissertations

"The electromagnetic field equations for microwave propagation through a rectangular waveguide filled with a lossy, isotropic, linear, inhomogeneous material are derived in matrix form and solved numerically by computer. The theoretical effects of photo-induced conductivity and dielectric constant variations on microwave attenuation, phase shift, and voltage standing wave ratio are plotted for typical examples in the X-band frequency range. The theoretical calculations indicate that a two order-of-magnitude change in the conductivity can produce a 25 db change in the attenuation or a 100 degree change in the angle of the reflection coefficient. The theoretical predictions are verified qualitatively by experiments …

Numerical Inversion Of The Laplace Transformation And The Solution Of The Viscoelastic Wave Equations, Abbas Ali Daneshy

Doctoral Dissertations

"In the numerical inversion of Laplace transform two general techniques of inversion are analyzed; a study of the procedures based on an expansion of f̄(s) by a polynomial in 1/s (Salzer's method) provides accurate results for certain ranges of t. A curvature criterion for the selection of the range of points for polynomial interpolation, and a geometric distribution in this interval markedly improves the range and the degree of accuracy of inversion. The results may be further improved by multiplying f̄(s) by 1/s of 1/s². Other procedures are based on approximation of f̄(t). This investigation includes a general review of …

Phase Equilibria And Thermodynamic Studies In The System Ca0-Fe0-Fe₂0₃₋Si0₂, Muharrem Timucin

Doctoral Dissertations

"A study of phase relations and thermodynamic properties of phases in the system CaO-FeO-Fe₂O₃-SiO₂ was conducted at 1450°C and 1550°C. The region of stability of the different phases was determined by microscopic examination of the specimens. The thermodynamic properties of liquid were determined by analyses of quenched samples equilibrated at oxygen pressures from about 10⁻¹¹ to 1 atm. Isothermal phase diagrams were constructed from data for 0, 5, 10, 20, and 30 weight percent silica sections of the CaO-FeO-Fe₂O₃-SiO₂ system, and the effect of temperature and increased silica additions on the oxygen solubility of the liquid oxides was measured. Multicomponent …

Spherical Antenna Array, Narong Yoothanom

Doctoral Dissertations

"The far field radiation pattern of an isotropic spherical antenna array with two types of element distributions, a latitude-longitude distribution and an approximately equally-spaced distribution, has been analyzed using Poisson's Sum Formula. Beamwidth expressions of both element distributions are found in various planes. All numerical results are given only for the case of 21 rings"--Abstract, page ii.

Signal Distortion In A Regenerative Frequency Divider, Carl Ray Ryan

Doctoral Dissertations

"A regenerative frequency divider can be constructed with one integrated circuit and a single-pole tuned circuit. The divider can be used as a means for reducing the modulation index of either deterministic or random signals. This reduction in modulation index can simplify many signal processing schemes. This technique can be used up to S-band frequencies. The mathematical model of the regenerative frequency divider corresponds very closely to that of a first order Phase Locked Loop (PLL). The loop gain is determined in part by the nonlinear element used in the feedback loop. The loop gain is also proportional to the …

X-Ray Determination Of Lattice Parameters And Thermal Expansion Coefficients Of Aluminum, Silver And Molybdenum At Cryogenic Temperatures, Claude Lowell Woodard

Doctoral Dissertations

"A multiple exposure back reflection diffraction camera was designed to mount on the vacuum jacket of a pressurized helium gas "Cryomite". With this design it is possible to obtain six diffraction exposures on a single film at any temperature in the range of 180 to 25°K. temperatures within this range are reached in short intervals and exposure periods are less than 30 minutes in a 2.875 inch (73.03 mm) diameter camera. Some of the advantages of this design are; direct measurements, multiple exposures on a single film, short exposures, direct compensation of film length changes due to evacuation or processing …

Turbulence Measurements In Drag Reducing Flow, Jorge Mario Rodriguez

Doctoral Dissertations

"Studies of the frequency response of hot-film wedge probes in viscoelastic fluids established their reliability as measuring devices and demonstrated that the objections raised by Metzner and Astarita (77) are not valid for wedge probes. The structure of turbulence in drag reducing soap and polymer solutions was studied using a hot-film wedge probe. Intensity of turbulence measurements in drag reducing fluids indicate that the structure of trubulence is strongly dependent on the condition of the solution. Rates of energy dissipation calculated at the center of the tube indicate that there is an increase in the rate of energy dissipated in …

An Optimization Approach To Well Spacing For Gas Storage Reservoirs, Jagannath Rao Ghole

Doctoral Dissertations

"A finite approximation to the conventional diffusivity equation describing compressible fluid flow through porous media has been developed with a view to apply it to the problems of optimum well spacing. An equilateral grid system has been employed to enable uniform well spacing for any number of wells. A numerical model has been developed on an IBM 360 - Model 50 computer, which simulates the pressure and saturation transience in the reservoir due to production impulses. This model has been used to maximize with respect to number of wells, the minimum well bore pressure reached throughout the specified withdrawal schedule. …

A Theoretical Study On The Interpretation Of Resistivity Sounding Data Measured By The Wenner Electrode System, Siew Hung Chan

Doctoral Dissertations

"This thesis deals with a theoretical study on the interpretation of resistivity sounding data measured by the Wenner electrode system. The objectives of this investigation are twofold: (i) to derive from the apparent resistivity data some suitable functions from which the resistivity and thickness of each member of the sequence of layers composing the earth may be determined, and (ii) to devise suitable methods for analyzing the resulting functions. In this investigation it is shown that the solution of the boundary value problem associated with an n-layered earth model leads to an integral equation for the Wenner electrode system. This …

Investigation By Neutron Diffraction Utilizing White Neutron Radiation, Arlen Ray Schade

Doctoral Dissertations

"The most probable reactor core neutron velocity was determined by analysis of data obtained from single crystals of copper and lithium fluoride. Derivation of the relationship between the maximum in experimental count rate and the most probable velocity, an error analysis of the method, and the computer routine are given for the method used to obtain the most probable velocity. The most probable velocity was used to index the maxwellian distributions from polycrystalline materials. Investigations were done with white neutron radiation of various silicon steel samples of different preferred orientation. A method is described by which the preferred orientation of …