Digital Commons Network^™

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 …

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 …

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. …

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, …

Characterizing Topologies By Continuous Selfmaps, Derald David Rothmann

Doctoral Dissertations

"Various topological spaces are examined in an effort to describe topological spaces from a knowledge of their class of continuous selfmaps or their class of autohomeomorphisms. Relationships between topologies and their continuous selfmaps are considered. Several examples of topological spaces are given and their corresponding classes of continuous selfmaps are described completely. The problem, given a set X and a topology U when does there exist a topology V either weaker or stronger than U such that the class of continuous selfmaps of (X,V) contains the class of continuous selfmaps of (X,U), is considered. M* and S** spaces are defined …

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.

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 …

Low-Lying Levels In Some Spherical And Rotational Nuclides By Coulomb Excitation And Radiative Capture Of Thermal Neutrons, Donald Allan Mcclure

Doctoral Dissertations

"The work presented in this dissertation was performed in order to obtain additional information on the level schemes and decay properties of several nuclei in an attempt to explain the observations in terms of an applicable nuclear model. Various nuclear models are discussed in Section II. A general review from the classical point of view of the Coulomb excitation reaction is discussed in Section III and the thermal-neutron-capture reaction is outlined in Section IV. The experimental equipment and procedure is discussed in Section V in which the ramper method of energy determination is outlined. This method allows the measurement of …

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 …

Noble Gases: A Record Of The Early Solar System, E. C. Alexander

Doctoral Dissertations

"Analyses of the noble gases in samples of iron meteorites are presented which indicate the following: 1. The inclusions of iron meteorites contain noble gases with a wide range of isotopic compositions. 2. The noble gas concentration and isotopic anomalies arc often grossly inhomogeneously distributed within a given inclusion and vary from inclusion to inclusion in a meteorite. 3. Silicate inclusions appear to be the most promising samples for I-Xe and Pu-Xe dating. 4. Graphite and troilite in addition to the silicate inclusion contain significant radiogenic ¹²⁹Xe anomalies. 5. The total I-Xe (and in the case of Toluca silicates total …

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 …

MöSsbauer Effect Studies Of Ferroelectric Phase Transitions In The Pbzro₃ - Pbtio₃ - Bifeo₃ Ternary System, James P. Canner

Doctoral Dissertations

"The Mössbauer Effect was used to measure the phase transitions in the following ferroelectric compounds: 95% PbZ4₀.₈Ti₀.₂ - 5% BiFeO₃ [and] 95% PbZ4₀.₇Ti₀.₃ - 5% BiFeO₃ and in the antiferroelectric compound: 95% PbZrO₃ - 5% BiFeO₃. The parameters obtained were the area under the resonance peak, the isomer shift, and the electric quadrupole splitting, all as a function of temperature. The ionicity, electric field gradient, and Debye temperature were determined for room temperature. The data are discussed in terms of the lattice vibration model of ferroelectrics and antiferroelectrics, and the structural phase transitions as recently defined for these compounds. The …

Radiative Lifetime Of The B¹Σ⁺ And B³Σ⁺ States Of Carbon Monoxide, John Robert Rogers

Doctoral Dissertations

"The radiative lifetimes of the B¹Σ⁺ and b³Σ⁺ excited states of carbon monoxide were measured at six different pressures: 10, 25, 50, 75, 100, and 125 microns of Hg. The lifetimes were obtained by observation of the radiative decay of the (0,0), (0,1), (0,2), and (1,1) bands of the Angstrom system and the radiative decay of the (0,1), (0,2), (0,3), and (0,4) bands of the Third Positive system. No pressure dependence of the lifetimes was observed for either system. The average lifetime of the v' = 0 vibrational level of the B¹Σ⁺ state was found to be 24.4 x 10⁻⁹ …

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 …

Statistical Inferences For Location And Scale Parameter Distributions, Robert Henry Dumonceaux

Doctoral Dissertations

"The problem of discriminating between two location and scale parameter distributions is investigated. A general test based on a ratio of likelihoods is presented. A test based on a Pearson Goodness of Fit statistic is also considered. Tables are given for discriminating between the normal and exponential, the normal and double exponential, the normal and extreme value, and also between the normal and logistic. For location and scale parameter distributions, two-sided tolerance limits are shown to always be obtainable by Monte Carlo simulation. A method for obtaining confidence intervals on the reliability at a fixed time t is also given. …

Statistical Inferences For The Generalized Gamma Distribution, Harold Walter Hager

Doctoral Dissertations

"Procedures for handling statistical problems with nuisance parameters are considered with special reference to problems in the three parameter generalized gamma distribution. Maximum likelihood estimation of the parameters of this density has been investigated. Properties of these estimates are established which make it possible to make inferences about the parameters. Discrimination between various models for life testing problems is discussed and the robustness of the Weibull model is advanced. The question of the existence of the maximum likelihood estimates of the parameters for all samples is raised. Empiric evidence is presented indicating that they may not exist for all small …

The Statistics Of Finite, One Dimensional Lattice Fluids, John Roger Glaese

Doctoral Dissertations

"A one dimensional lattice fluid in which particles are allowed to assume only discrete positions is proposed. Particles are free to move from one lattice site to another interacting through a variety of potentials, including the Lennard-Jones type. The model allows the partition function to be evaluated as a discrete sum over the allowable configurations. Both the canonical ensemble and grand ensemble are treated by computer and a third, the pressure ensemble, is considered and shown to be useful in the theoretical treatment of lattice systems. The thermodynamic behavior of various systems is investigated in both the canonical and grand …

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 …

I A Study Of The Basicities Of Some Aryl Methyl Sulfoxides Ii A Study Of The Hydrolysis Of Arenesulfinamides In Basic Aqueous Ethanol, Joseph Brian Biasotti

Doctoral Dissertations

No abstract provided.

The Extension Of A Locally Compact Local Group To A Global Group, David Warren Cohen

Doctoral Dissertations

No abstract provided.

Measurement Of Ionospheric Absorption By The Cosmic Radio Noise Method, J Ronald Earhart

Doctoral Dissertations

No abstract provided.

Analysis Of A Focus Log Electrode In A Non Homogeneous Medium, John Julian Zenor

Doctoral Dissertations

"The mathematical model presented for the focused logging system is applicable to any resistance logging tool of the electrode type. Horizontal or cylindrical resistance interfaces may be included in any combinations. The tool and its environment are compartmentalized, and the integral form of the condition for continuity of current is applied to each compartment. Acceleration methods are applied to the iterative solution of the resulting large-scale system of linear equations. Two specific models are presented, one for the study of the effects of invasion and the other for the study of the effects of bed thickness on the apparent resistivity …

An Experimental Determination Of The Homogeneous Nucleation Rate Of Water Vapor In Argon And Helium, Louis Benton Allen

Doctoral Dissertations

"An expansion type cloud chamber was used to measure the nucleation rate of water vapor in an atmosphere of helium and argon. A careful study was made of the thermodynamic characteristics during the expansion so that the nucleation data could be interpreted with reasonable accuracy and consistency. A fine wire thermocouple was used to measure the gas temperature during the course of an isentropic expansion in the dry chamber. When the finite heat capacity of the thermocouple is accounted for, it is found that there is almost perfect agreement with the temperature calculated from the equation of state and the …

Recombination Statistics For The Neutron-Induced Base Current Component, Ming-Chwan Chow

Doctoral Dissertations

"This paper presents a derivation of the recombination statistical model for the neutron-induced base current component. The derivation was based on the assumptions: 1) the current equation for the induced current component developed by Goben is valid; 2) the Shockley-Read-Hall statistics for holes and electrons are applicable; and 3) the recombination statistics derived by Sah, Noyce and Shockley, for sites in the bulk space-charge region are valid. Several examples were presented to emphasize accuracy of this derived model for predictions. This paper shows that the recombination process may be described by a mathematical model, recombination statistics which depend on the …

Surface Self-Diffusion On Nickel (111) By Radioactive Tracers, James Ronald Wolfe

Doctoral Dissertations

"Surface self-diffusion coefficients have been measured by a radioactive tracer method over the temperature range 614⁰ to 840⁰C on nickel (111) surfaces characterized by LEED. Previously unrecognized tracer evaporation during surface diffusion resulted in restricted spreading of the tracer at higher temperatures. A theoretical treatment of the tracer evaporation phenomenon is presented and subsequently used in the analysis of the data. The temperature dependence of the surface self-diffusion coefficient (D_s) for nickel (111) can be represented, over the experimental temperature range, by a single Arrhenius type relationship...Arguments are presented to justify an adatom surface diffusion mechanism which is …

A Study Of Succinic Dehydrogenase, Indole Acetic Acid Oxidase, Nitrate Reductase And Cytochrome C Reductase In Hygrophorus Conicus, Jagdish M. Mehta

Doctoral Dissertations

"The activity of the enzyme succinic dehydrogenase (succinate : phenazine methosulfate oxidoreductase, EC 1.3.99.1) of Hygrophorus conicus, a member of a class of fungi known as basidiomycetes, was found to be stimulated by nitrate. Two substances were tested as electron acceptors in the measurement of succinic dehydrogenase activity. Of the two substances tried, phenazine methosulfate and brilliant cresyl blue, the former was found to be the best. Nicotinamide adenine dinucleotide (NAD⁺) was a necessary cofactor for the enzyme and could be readily dissociated from the enzyme. The enzyme has the properties of a high molecular weight nucleo- or lipoprotein.

The …

Signal Theoretic Characterization Of A Function Using Positive Exponential Basis Functions, James Julius Baremore

Doctoral Dissertations

"A signal theory characterization of a time function or signal is a representation of the function throughout a sample interval by an orthogonal basis function expansion. The characterization described here obtains the coefficients in the expansion by processing the input waveform, in real time, through a system of three terminal passive RC filters. The outputs of the filters are sampled periodically and the coefficients of the basis function expansion in that interval are related to these values. The basis functions result from an exponential transformation applied to the Legendre polynomials and are orthogonal in time over the sample interval. The …

The Lifetime And Effective Quenching Cross Section Of The 6²P₃/₂ State Of Thallium, Robert Charles Pickett

Doctoral Dissertations

"The measurement of the lifetime of the metastable 6²P₃/₂ state of thallium is discussed. Measurement of time varying optical absorption by time sampling techniques is explained for the study of the decay of the metastable atom concentration following a pulsed radio frequency discharge. The decay of the thallium radiation from optically allowed states terminating on the metastable state is measured at nine different thallium densities in the afterglow of the discharge. This radiation repopulates the metastable state and is displayed on an oscilloscope. The metastable lifetime is measured as a function of the thallium density at three different r-f power …

Hrva - A Velocity Analysis Technique For Seismic Data, John Charles Robinson

Doctoral Dissertations

"A High-Resolution Velocity Analysis (HRVA) has been developed for the determination of the root-mean-square subsurface-velocity energy spectrum from gated seismic data which has been normal-moveout corrected. All calculations are performed in the frequency-space or frequency-wavenumber domain; seismic gates are transformed from the time-space domain via the Fast Fourier Transform algorithm. HRVA is not restricted to the investigation of apparent horizontal velocities which have associated stepout values that are integral multiples of the time sampling interval, as are the existing correlation techniques. The technique liberally exploits the inexistence of significant energy in the higher frequency harmonies of seismic data, resulting in …