Engineering Commons^™

The Amino Acid And Monosaccharide Content Of The Cell Walls Of Thiobacillus Thiooxidans, Edward Hibbert Crum

Doctoral Dissertations

"The objectives of this investigation were: (a) to culture large quantities of Thiobacillus thiooxidans cells, (b) to find an acceptable method of rupturing the cells, (c) to find an acceptable method of isolating the cell walls, and (d) to analyze the cell wall components, especially the amino acid and sugar components. The strain of T. thiooxidans used for this investigation was American Type Culture Collection Number 8085. The surface active agents Tergitol 08 and Tween 80 were investigated for their ability to reduce the lag period found in the growth of T. thiooxidans. Although a concentration of 12.5 ppm Tween …

Vapor Pressure And Evaporation Coefficient Of Cadmium Oxide, R. Tom Coyle Jr.

Masters Theses

"Knudsen effusion experiments were carried out on CdO in fused silica crucibles at temperatures of 918°K, 1008°K with orifice areas from 2.742x10^-3 cm² to 30.52x10^-2 cm². The experiments were made in a molybdenum-wire, resistance-heated vacuum furnace. Several orifice areas were used at each temperature and reciprocal pressure versus orifice area plots were made. These plots yielded an upper limit to the evaporation coefficient of. 4.15x10^-2. An equilibrium constant for the vaporization reaction

CdO(s) = Cd(g) + 1/20₂ (g)

of

log Keq = 11.12 - 1.952x10⁴/T.

was obtained. Second and third …

Stresses In A Thick Spherical Shell, David Wayne Moore

Masters Theses

"This thesis reports a method to evaluate the stresses in a segment of a thick spherical shell. In the numerical examples loads due to thermal expansion as the shell is constrained at the free edge and a dead load acting vertically downward were considered for a shell assumed pinned but free to rotate and for a shell assumed completely fixed at the edge. A concrete shell was specifically studied but the method would also apply to a shell of any homogeneous, isotropic material"--Abstract, page i.

Small-Signal Impedance Of A Junction Diode At High Injection Levels, John E. Lundy

Masters Theses

"A mathematical expression for the driving point impedance of a junction diode at high injection levels is developed. To evaluate the impedance versus frequency characteristic of a diode, it is necessary to know the minority carrier lifetime as a function of injection level and doping density in the base (lightly doped) region, the junction area, and the base width. The interesting characteristic of the diode impedance at high injection levels is the inductive reactance displayed by the diode.

The expression is developed by solving the differential equation for charge flow in the base region of a diode assuming space-charge neutrality …

Centrifugal Model Study And Finite Element Analysis Of Stress Near A Fault, Christopher Haycocks

Doctoral Dissertations

"The adverse effects of faults on the stability of underground openings has long been realized. To date, however, discontinuities and most other types of geologic heterogeneities have not been amenable to mathematical analysis using the classical theories of elasticity and plasticity. This investigation examines the stress distribution around a single discontinuity and compares the experimental and numerical methods used for the analysis. The theory of elasticity, employing the equations of compatibility, equilibrium etc., was used to determine a stress function for the stress distribution around a circular hole loaded in a centrifugal field. The analysis was terminated after the stress …

Film Boiling From Horizontal Plates With Low Thermal Capacity, K. M. Ragsdell

Masters Theses

"The object of this investigation was to obtain data for saturated film pool boiling from a low thermal capacity flat plate at atmospheric pressure. A test plate, constructed from resistance strip, was placed horizontally in a pool of liquid, and was heated electrically. Refrigerant-11 and nitrogen were used as the boiling liquids. Heat transfer results were obtained in both fluids over a temperature range of approximately 1200F⁰ (400-1600⁰F). Surface size, roughness and orientation effects were observed for flat horizontal heated surfaces with one dimension near the most dangerous wavelength. No surface material effect was observed. Excellent correlation of the data …

Shutdown Reactivity Worth Of Reactor Control Rods By A Subcritical Multiplication Method, Leslie Roger Conner

Masters Theses

"Two modified subcritical multiplication methods for measuring the reactivity worth of control elements were developed and investigated. The first involved the calibration of a subcritical count interval by the asymptotic period method. The second involved the calibration of a subcritical count interval by a rod interchange with the reactor regulating rod which had previously been calibrated by the asymptotic period method. The accuracy of these methods is relatively poor. this inaccuracy is due to shadowing effects and to the spatial harmonics which exist in the core. An investigation of the spatial harmonics to determine the best location for the neutron …

A Class Of Pattern Recognition Machines, Shaw Yih Chung

Masters Theses

"The classification of signals through the use of pattern recognition techniques may be viewed as a statistical classification problem since at least some pattern classes are analog signals which have been contaminated by additive noise. In order to represent these signals at the input of a pattern classifier they are sampled and a vector and an m-dimensional vector space used to describe the pattern. Consequently, these pattern samples are processed to determine the parameters of the statistics. In this study the additive noise was assumed to be Gaussian in nature. This study was based on a priori knowledge of the …

A Study Of Film Boiling Of Liquid Nitrogen And Liquid Argon Over A Wide Pressure Range With Cylindrical Heaters, V. J. Flanigan

Masters Theses

""A film boiling heat transfer study was conducted with three different diameter cylindrical copper heaters over a wide range of pressures for nitrogen and argon with the heat transfer surface in the horizontal position. The data were compared to the commonly used film boiling heat transfer relations. The common relations were found to be considerably in error for the range of variables covered in this investigation. A semi-empirical equation for corresponding states fluids which correlates the available data as a function of the reduced temperature and reduced pressure was derived and discussed"--Abstract, page iii.

Estimation Of Regional Trends In Gravity Using Gram Orthogonal Polynomials, Stanley Dean Thompson

Masters Theses

"A computer program is presented which estimates the trend in a rectangular array of gravity measurements. It is assumed that the regional trend of gravity may be estimated by a low-order polynomial. The method of least-squares is applied to solve for the low-order polynomial which best approximates this trend. Gram orthogonal polynomials are used in the solution of this least-squares surface fit. The program is tested on a known polynomial and on some hypothetical Bouguer gravity data and found to approximate the ʺregional trend of gravity in these cases. The importance of eliminating any significant noise in the observations before …

Velocity Profiles In Viscoelastic Drag Reducing Solutions, Luis Gustavo Florez E.

Masters Theses

"Turbulent velocity profiles in viscoelastic drag reducing solutions were measured using hot-film anemometer and Pitot tube techniques. Data were obtained in a solution of one per cent aluminium [sic] dioleate in toluene and in 0.2 and 0.4 per cent solutions of polyisobutylene (PIB) L-200 in cyclohexane. Velocity profiles were also obtained for comparison in toluene and cyclohexane by both techniques. By integrating the Pitot tube velocity profiles, large flow rate discrepancies between integrated and measured flow rates were found for the drag reducing polymer and soap solutions. This discrepancy was not observed in the hot-film anemometer measurements. The hot-film anemometer …

Compressive Creep Of High Alumina Refractories, Vernon Lee Burdick

Masters Theses

"The deformation of refractory materials consisting of 90% sintered or fused alumina plus 10% silica was measured at temperatures from 1450 to 1515⁰C and a compressive stress of 100 psi. Creep rates and activation energies were determined from the steady state portion of deformation vs. time data and correlated with the mineralogical composition. Supplemental measurements included x-ray diffraction, electron probe microanalysis, apparent porosity and tensile strength. conditions having an important effect upon the mineralolgical composition were: (1) duration of heat treatment, (2) amount of sodium oxide impurity, and (3) reactivity of the alumina grain. Prolonged heat treatment and sodium oxide …

Some Effects Of Nickel On The Microbial Population Of Activated Sludge, Virgil Eugene Carr

Masters Theses

"The purpose of this investigation was to study the effects of nickel on the microbial population of activated sludge, to establish a relationship between effluent quality and changes in microbial population, and to determine the fate of nickel applied. Five one liter fill and draw activated sludge units were fed settled domestic sewage and received constant daily nickel doses of 1-10 mg/l, and a 50 mg/l slug dose applied after 27-30 days of operation. The parameters used were the chemical oxygen demand (COD) of the effluent and membrane filtered effluent, mixed liquor and effluent total suspended solids, mixed liquor volatile …

A New Performance Index For Sensitivity And Energy Optimization., Mohamed Zafer Dajani

Masters Theses

"The principal aim of this thesis is to present a new index of performance which when minimized will simultaneously optimize the system energy and sensitivity function of a multivariable linear control system. With this performance index it is usually desirable to discriminate between the sensitivity factor and the energy term by weighting them differently. Two types of weighting factors are presented. Since it is not easy to minimize that performance index for all types of problems, further research is suggested to find methods of solution for such problems. Illustrative examples demonstrate the optimization process and the type of assumptions needed …

Hydrologic Characteristics Of Shallow Bedrock Aquifers In The Vicinity Of Norman Creek, Central Phelps County, Missouri, Michael A. Nawrocki

Masters Theses

"Groundwater is becoming increasingly important as a source of water supply in the United States. Consequently, the prediction of well yields is a vital concern. In order to predict the quantity of water which can be reduced from a given aquifer it is necessary to know the aquifer's hydrologic characteristics. Many theoretical formulae have been derived for determining the aquifer characteristics. To date, these formulae have been tested mainly on unconsolidated and clastic rock aquifers. It has never been shown that these formulae can also be consistently applied to carbonate aquifers which underlie regions of karst terrain. This paper summarizes …

Fault Detection In Combinational Networks, Alexander Rahm

Masters Theses

"This paper presents an algorithm for locating a failure in combinational logic networks, which is a problem of importance in the maintenance of computer systems. The procedure is based on the "path sensitizing" idea for fault detection. The networks considered are non-redundant, consisting of AND, OR, and NOT elements. The class of faults investigated is that which causes a connection to appear to be logically suck-at-one or stuck-at-zero, and only single failures are treated. It is shown that the failure is generally located to a specific "fault group"--Abstract, page 2.

Scanning Properties Of Unsymmetrically Loaded Aperture Arrays, Gary Dean Brunner

Masters Theses

"Radiation patterns resulting from an array of waveguide-fed apertures, filled with assymmetrically [sic] cut dielectric inserts, in an infinite ground plane were investigated. The results of Blumberg and Hemmen concerning single apertures were applied to a two-aperture array, with emphasis upon obtaining an array capable of scanning in the far field through changes in the permittivity of the assymmetrically [sic] cut dielectric inserts. Scanning was shown to be possible with up to a 60⁰ scan angle with a "push-pull" method of varying permittivities, in which the permittivity of one insert is raised while the other is lowered. The aperture field …

Annealing Characteristics Of Neutron Irradiated Silicon Transistors, Joseph Robert Chott

Masters Theses

"When a transistor is subjected to neutron irradiation, a component of base current proportional to neutron fluence is induced. From the effects of annealing on the base and collector currents, the conclusion was drawn that there is an apparent difference in the annealing characteristics between the neutral and the space-charge regions of the semiconductor device. This study of the anomalous annealing indicates that the neutron-induced component of base current is a result of one, or a combination, of the following mechanisms: a quasi-tunneling recombination phenomena in the emitter-base space-charge region, or an influence of the p-n junction electric field on …

Characteristic Impedance Of Open Microstrip Transmission Lines Having Finite Thickness And Multiple Dielectric, Philip Julian Carter

Masters Theses

"A computer program is provided for determining the characteristic impedance of microstrip transmission lines having finite thickness. Infinite and finite ground planes are incorporated into the program. The programmer need only supply information in the form of a data card. This procedure is clearly outlined.

Graphical solutions of characteristic impedance for multiple dielectric microstrip transmission line problems are obtained using a discrete resistive analogue. Computer network analysis programs are viewed as having several advantages not possessed by the physical resistive analogue"--Abstract, page 2.

Continuous Countercurrent Evaporation Through Porous Water-Repellent Membrane With Pressure Above Atmospheric, Yung C. Hsu

Masters Theses

"An experimental method for measuring mass transfer rates at pressures above atmospheric has been developed for the case of continuous countercurrent evaporation through porous water-repellent membranes. The final developed equipment is suitable for operation under pressures up to 50 psig and at temperatures near the boiling point of 7% salt water when high flow rates are reached. Rates of evaporation of water through the membrane were measured, and the data and results were used to examine the effects of operating conditions on the over-all mass transfer resistance. Least squares equations for fitting the data were also obtained. Over-all mass transfer …

A Programmed Synthesis Procedure For Asynchronous Sequential Circuits, Robert Judson Smith

Masters Theses

"The synthesis procedure for large asynchronous normal fundamental-mode sequential circuits is time-consuming and tedious when performed manually. This paper describes a series of computer programs which, given a machine specification in flow table form, automatically produces simplified normal form implementation design equations. The user may specify that either minimum-variable state assignments, or more rapidly generated near-minimum-variable codes be found. Next-state equations are formed using the generated state assignments and converted to simplified sums of products. Sample machines having flow tables of up to eighteen rows by four columns are synthesized"--Abstract, page ii.

Construction Of A Laboratory Type, Convertible Excitation Argon Laser, Arthur P. Reckinger

Masters Theses

"The purpose of this thesis is to describe the construction of a general purpose, convertable [sic] excitation, laboratory type, argon laser. Quartz tubing was used in the final model while attempts to use alumina were made during earlier work. The final model has total optical power output of 230 mw at a discharge current of 29 amperes in the dc excitation mode. Provision was also made to utilize RF or pulsed excitation. The device is built so that several values of optical transmittance are available with a wide range of mirror placement"--Abstract, page ii.

A Transmission Electron Microscopy Study Of Some High Strength Plain Carbon Steels, George Joseph Vytanovych

Masters Theses

"Methods of preparing foils of high strength, heat treated, plain carbon steels for examination in the electron microscope by the transmission technique were perfected and are described. Two processes for the initial thinning of a bulk sample were successful. A chemical process was found to be more rapid but not satisfactory for small samples. A mechanical process was slower, but was applicable to the smaller specimens. Electro-polishing the thinned material yielded acceptable foils from which photomicrographs of good quality were obtained. The microstructure of the high strength steel samples showed typical tempered martensite. No reasons for the differences in ductility …

The Transient Dynamics Of Plane Mechanisms, Navnit Chhaganlal Mehta

Doctoral Dissertations

"Accurate determination of dynamic characteristics of mechanisms has become more important with increased requirements on speed, efficiency and precision. Many devices, such as circuit breakers and computing mechanisms, operate under purely transient conditions and actuation time places a serious limitation on the response of the system of which these devices are a part.

In the classical analysis, whether it be graphical or analytical, the mechanism is assigned a specified position and state of motion from which the forces required to produce the motion can be determined. The inverse problem of specifying the driving force and determining the resulting motion, which …

A Structural Investigation Of Bismuth Ferrate And The Bifeo₃-Pbzro₃-Pbtio₃ Ternary System, Gary D. Achenbach

Doctoral Dissertations

"Solid state reaction of Bi₂O₃ · Fe₂O₃ mixtures was shown to yield impure bismuth ferrate, BiFeO₃, containing Bi₂Fe₄O₉ and residual Bi₂O₃; this places the results of much of the literature based on BiFeO₃ prepared by this technique in suspect. Single phase polycrystalline BiFeO₃ was prepared by multiple nitric acid leaching of sintered samples which contained excess Bi₂O₃ to prevent the formation of Bi₂Fe₄O₉ during sintering. X-ray and neutron powder diffraction data indicate that …

Programmed State Assignment Algorithms For Asynchronous Sequential Machines., Wayne L. Schoeffel

Masters Theses

"An important step in the synthesis procedure for realizing a normal fundamental mode asynchronous sequential circuit is the internal state assignment. Although systematic methods have been developed to construct minimum-transition-time state assignments, they become long and tedious with hand methods for machines with more than 7 or 8 internal states. To extend the application of these algorithms to larger problems, this paper presents an efficient digital computer program for generating minimum-variable state assignments. An alternate program is also presented which, though shorter, does not guarantee a minimum-variable assignment"--Abstract, page ii.

A Determination Of The Rate Of Evaporation Of Zinc At Atmospheric Pressure., Yu Ming Su

Masters Theses

"Measurements of evaporation rates of zinc in three different residual gases, e.g., argon, carbon monoxide, and hydrogen at one atmosphere pressure, were made. It was found that the rate of evaporation of zinc in one atmosphere of argon was almost the same as that in carbon monoxide, while the rate in hydrogen was almost twice the rate in argon or carbon monoxide. Measurements of evaporation rate of zinc in one atmosphere of argon-oxygen mixtures were also made. The evaporation rate was considerably reduced because the formation of the oxide film retards the zinc vapor escaping from the evaporating surface"--Abstract, page …

The Design And Construction Of An Apparatus For The Plane Wave Analysis Of Mufflers, Stephen Philip Buckley

Masters Theses

"In the following report, a method for evaluating the attenuation characteristics of a general muffler as well as the design, construction and use of the associated apparatus are described. The method combines accepted plane wave theory and experimental techniques into a relatively straightforward approach to the analysis of acoustic filters. Equations are developed to cover the frequency range between 300 and 4000 cycles per second. Deviations from these equations extend the use of the equipment to low frequencies without the need for unduly long and cumbersome apparatus. This method, which may be called the standing wave method, utilizes a standing …

Synthesis Of Filters Using Distributed Rc Networks, Mario Nader Nader

Masters Theses

"This paper deals with the problem of realizing filter and delay functions by means of distributed RC devices. The method is made possible through the use of a distributed RC network which possesses rational admittance parameters. The technique of approximating transfer functions using polynomial factors that are ration in e[superscript (a square root of s] is explained. These factors are used to approximate the magnitude and phase characteristics for a low-pass filter. This filter is then realized using the admittance functions studied by Wyndrum, the "s->W" transformation, and Richard's theorem. Those factors are then used to approximate high-pass and …

A Kinetic Study Of Ti⁺³ Oxidation To Ti⁺⁴ In Hydrofluoric Acid Solutions, Kuo-Shein Shen

Masters Theses

"The purpose of this investigation was to study the oxidation rate of Ti⁺³ to Ti⁺⁴ in hydrofluoric acid solutions in the absence of air. The concentration of hydrofluoric acid was varied from 0.25 to 2.00 M and the concentration of titanium from 0.05 to 0.50 M. The temperature was controlled at 25⁰C. The reaction rate was relatively slow. In most instances, less than 50 percent of the Ti⁺³ was oxidized during a period of 100 hours"--Abstract, page vii.