Engineering Commons^™

Ptimal Feedback Control Of The Radioactive Voltage Standard, David William Braudaway

Electrical and Computer Engineering ETDs

The quest for new and different techniques of establishing and maintaining the electrical values is continual Among the techniques desired are those for producing highly predictable sources of voltage. Described in this dissertation is a working device developed around one such technique, the research done to define the system and the synthesis of the automatic control which makes it practical. In this system, the reproducibility of the voltage output is derived from the predictability of the decay of a radioactive heat source.

The Influence Of Ionic Polarizability On The High Temperature Mechanical Properties Of Ionic Crystals, William A. Johnston

Masters Theses

No abstract provided.

Transient Pulse Transmission Using Impedance Loaded Cyclindrical Antennas, David E. Merewether

Electrical and Computer Engineering ETDs

Two aspects of the problem of pulse transmission using impedance loaded cylindrical antennas have been considered. First, an approximate solution is obtained for the current distribution on a thin cylindrical antenna driven at an arbitrary point along its length. This solution may be applied to an antenna of any length, and its simplicity makes the current distribution rapidly computable. This solution is ideal for the prediction of the transient electromagnetic field radiated when an arbitrary voltage transient is impressed across the input terminals of a long, thin, cylindrical antenna loaded with lumped im­pedances. Second, an antenna synthesis procedure was evolved. …

A High Current Density Pulse-Mode Proton Source: Preliminary Study, Warren D. Smith

Electrical and Computer Engineering ETDs

A neutron source which produces high density pulses is useful, for example, in the simulation of an atomic blast or in neutron activation chemical analysis. Rather than forming pulses by deflecting the deuteron beam emitted from a continuous source of deuterons onto and off of a tritium target, it was decided to investigate the possibility of transient deuteron production. Proton sources were studied in place of deuteron sources because of the availability of hydrogen gas for experimentation. An experimental system was set up in which transient electrical discharges through hydrogen could take place. It was hoped that discharges could be …

A Three-Component Force Transducer For Monorail Rocket Sleds, Vincent Warren Gorman

Mechanical Engineering ETDs

A three-component force transducer which permits measurement of the vertical force, the cross-track force, and the roll moment about an axis parallel to the track was developed for use on monorail rocket sleds. For this force system it was found that the maximum allowable load for both the vertical and cross-track components was approximately 28,000 pounds, and the maximum allowable roll moment was approximately 45,500 inch-pounds. The transducer, mounted between the slipper and sled, uses strain gages as component sensing elements. The strain gage bridges were statically calibrated for each component of load the transducer was designed to measure. In …

The Effect Of Transient Ionizing Radiation Upon Schottky Barrier Diodes, Robert H. Schnurr

Electrical and Computer Engineering ETDs

The theory of operation of the Schottky barrier diode was reviewed. The complications caused by a more accurate space charge formulation were discussed. Consideration of image effects, tunneling, interfacial dielectric layers, surface states, and minority carrier current was also included.

The interaction of ionizing radiation with semiconducting materials was reviewed. The behavior of a Schottky barrier diode in an ionizing radiation environment was considered. The resultant model for the Schottky barrier diode is analogous to a p-n diode with one side having a very high dopant concentration.

Tests were performed upon GaAs and silicon Schottky barrier diodes, using a 2 …

The Dynamic Low Cycle Testing Machine: (Design And Calibration), Michael J. Shannon

Mechanical Engineering ETDs

The design and development of a loading device for subjecting a reversed shear specimen to a pulsed dynamic load is described. The development includes calibration technique to confirm that design criteria had been met. A relationship between plastic deformation and peak tensile load is presented.

Isotope Effect Of Interstitial Diffusion Of Carbon In A Dilute Fe-Si Alloy, Edward T. Yen

Masters Theses

"The isotope effect of carbon interstitial diffusion in a Fe-2.75at%Si alloy has been measured at -3.10°C using the disaccommodation technique. The disaccommodation has been analyzed in terms of two relaxation processes which are discussed on the basis of the reorientation mechanism of carbon interstitials at Fe-Fe sites and Fe-Si sites respectively. The ratios of the relaxation times [tau]₁₃/[tau]₁₂ are 1.0382 for the former and 1.0072 for the latter relaxation process. This result is discussed on the basis of many-body reaction rate theory"--Abstract, page ii.

The Identification And Evaluation Of Toxic Effects Of Organic Micropollutants, John Warren Smith

Doctoral Dissertations

No abstract provided.

Waveform Distortion Caused By A Plasma Sheath, James R. Carl

Masters Theses

"A short burst of electromagnetic energy that propagates into and through a plasma medium can react with the plasma medium in several different ways depending on both the characteristics of the plasma and of the pulse. This thesis derives approximations for the plasma transfer function at low pressure (high altitude) and at high pressure (low altitude). The mechanisms that can change the shape of a waveform, in general, are dispersion and breakdown. dispersive distortion at low altitude is shown to exist for electron concentrations well above the resonant concentration for plasma sheaths that are thin compared to one wavelength. Several …

Drag Reduction In Hydrocarbon Soap Solutions, Ian Radin

Masters Theses

"Turbulent flow pressure drop measurements were made for solutions of aluminum dioleate (soap) in toluene at concentrations of 0.2, 0.5, 0.75 and 1.0 per cent. Tube diameters ranged in size from 0.01 to 2.0 inches. The results of these measurements differed from those observed in aqueous systems. Higher concentrations (at least 0.75 per cent) were required before drag reduction was observed. Although fresh solutions were somewhat sensitive to shearing, once a solution was over about two weeks old it showed little further mechanical degradation. Although in the toluene solutions, wall shear stresses were reached which were over an order of …

The Damage Assessment Of Thermally Shocked High Density, High Purity Aluminum Oxide, John H. Ainsworth

Doctoral Dissertations

"The traditional approach to thermal shock testing in brittle materials has been to determine the temperature difference required to nucleate cracks in these materials. Recent work has indicated that the degree of damage after crack nucleation should be an additional consideration. The degree of damage resulting from cooling thermal shocks has been the primary consideration of the present work. Test specimens of two geometries: long, solid rods and short, solid cylinders were quenched from selected temperatures into ice water. The degree of damage was determined through strength measurements and sonic damping analysis. Initial damage occurred at a temperature difference above …

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 …

Nonparametric Sequential Detection, James Charles Fowler

Doctoral Dissertations

"This dissertation extends the theory of the Wilcoxon-Mann-Whitney U statistic so that this statistic can be used to perform sequential tests on hypotheses. This sequential test procedure makes use of a sequential ranking procedure similar to the one first introduced by Parent. The operating-characteristic function and average number of samples function for this new test are calculated as a function of the signal to noise ratio. The test is then shown to be efficient for several forms of alternatives with an efficiency of 95% against the Wald Sequential Probability Ratio Test for a constant signal in normal noise. Finally, the …

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 …

Zap - A Computer Program To Predict Fission Product Concentrations As A Function Of Neutron Flux, Irradiation And Cooling Times, Bruce Earl Koopmann

Masters Theses

"The development of a computer code was undertaken to calculate the fission product nuclide concentration for spent fuel discharged from a nuclear reactor, as a function of irradiation time, cooling time, neutron flux, and element cross section. The necessary input data was prepared from the basic nuclear data for fission of uranium-235 and plutonium-239. Calculations are also made for total or selective element beta heating and total gamma flux according to user selected input groups. These calculations would be useful in fuel element shielding, cooling, shipping and processing studies"--Abstract, page ii.

A Fluidic Liquid Level Control System, Vinod Kumar Verma

Masters Theses

"The prime objective of this investigation was to design and construct a working "Fluidic liquid level control system", and to make a functional study of the characteristics of the devices employed therein. A working model of a "fluidic liquid level control system" is developed and experimental data is collected to describe the functional characteristics of the fluidic circuits employed. The system contains a pressure sensitive, variable frequency oscillator; appropriate demodulation stages to convert the variable frequency alternating signal into a varying non-alternating signal; and on-off control elements in the final stages"--Abstract, page ii.

Dynamic Capacitance Of Metal-Oxide-Semiconductor Field-Effect Transistors, Marion Wendell Tucker

Masters Theses

"A transient peak was observed for MOSFET devices when measuring the dynamic capacitance versus applied gate voltage for various configurations at low frequencies. This peak is absent in conventional steady-state ac measurements. Since the peak is also absent in high grade devices and at high frequencies a possible explanation in terms of surface state traps is discussed for the observed phenomena"--Abstract, page ii.

Chemical Precipitation Of Phosphorous With Sodium Aluminate And Alum In The Activated Sludge Aeration Chamber, Richard Charles Vedder

Masters Theses

"The purpose of this investigation was to study the removal of phosphorus by chemical precipitation with sodium aluminate and alum in the activated sludge aeration chamber, and determine the effect of the aluminum to phosphorus ratio and the mixed liquor suspended solids concentration on the phosphorus removal efficiency and the effect of the precipitants on the removal of organic pollutants in the activated sludge process. The studies were conducted on settled domestic sewage in three bench-scale continuous flow activated sludge units supplemented with jar tests. Major parameters employed included influent and effluent total phosphorus and chemical oxygen demand (COD), mixed …

The N-Wire Exponential Transmission Line, Vernon Ray Stanley

Masters Theses

"This paper deals with the n-wire exponentially tapered transmission line. A characteristic impedance is defined, and the results of terminating in this impedance are investigated. A very long line and the condition of no reflections are considered, and the conclusions are compared. Finally, three specific 3-wire line problems are worked with a characteristic impedance termination and a unit step input"--Abstract, page ii.

Transient Response Of A Class Of Distributed Systems, Jaw-Shyong Tzeng

Masters Theses

"The transient response of uniform distributed systems with any transfer function that is rational in w=e[square root of Ts] can be analyzed with the basic form of the transfer function [1 over (w-a)] after partial fraction expansion, where the pole a can be real or complex in the w plane. with the complex pole within the stable region in the w plane, there are only two possible combinations of the basic transfer function [1 over (w-a)], i.e. [1 over (w-a)] ł [1 over (w-a*)], for physical realizability. The imaginary part of the transient response of the basic transfer function [1 …

A Simulation Of The Transistor By Computer Using The Linvill Diffusion Model, Clifford D. Skouby

Masters Theses

"This investigation involves the construction of an analog computer model of the transistor. The computer model is based upon the Linvill diffusion model. The equations for the Linvill diffusion model were programmed on the computer by making certain approximations. Different models, using different approximations, were used for the different regions of operation of the transistor. A composite analog model was constructed by combining the models for the restricted regions, giving a general model good for all regions of transistor operation. This analog diffusion model was modified to account for the effects of junction capacitance and base resistance. The modified analog …

The Analysis Of A Phase-Locked Loop By The Functional Expansion Method, Hugh Francis Spence

Masters Theses

"The time response of a generalized second order Phase-Locked Loop to step and ramp inputs is described by a functional power, truncated at the third order term. The responses given by the functional power series differs from the analog simulation by less than 6% when the inputs are below 2.0 rad (rad/sec)"--Abstract, page ii.

An Unsteady-State Method For Determining The Thermal Conductivity Of Materials, Richard H. Bulmer

Masters Theses

"Originally this work was initiated to develope [sic] a method for measuring the thermal diffusivity and thermal conductivity of metals. Due to the characteristics of the method and the equipment used, it was concluded that the technique is not suitable for materials of high conductivity. However, results show that the apparatus is valuable for the determination of the thermal diffusivity of relatively poor heat conductors. The favorable characteristics of the method are its rapidity and basic simplicity"--Abstract, page ii.

A Formal Description Of The Scc 650 Digital Computer, Hardy J. Pottinger

Masters Theses

"The requirements of a descriptive language for automated digital computer design are presented. Y. Chu's Computer Design Language is then used to describe the logic of the SCC 650, a small general-purpose digital computer at UMR. Chu's language is found to be the best language available to the designer for both documentation and automatic translation into Boolean Equations"--Abstract, page ii.

An Ultrasonic Pulse Generator Using The Transducer As A Frequency Determining Element, Donald E. Watke

Masters Theses

"This paper describes the development of a method of ultrasonic pulse generation in which the transducer determines the frequency of oscillation. A definite advantage of this method is the ability of the frequency of oscillation to change with changes in the transducer mechanical resonant frequency. This maintains peak efficiency at all times. The method is demonstrated in a small sonar transmitter but could be applied to any area involving driven ultrasonic transducers"--Abstract, page ii.

Kinetics Of The Formation Of Strontium Zirconate, W. H. Parker

Masters Theses

"The decomposition rate of strontium carbonate (SrC0₃) was measured using a TGA apparatus. It was found to deviate slightly from zero order classical reaction. The rate of formation of strontium zirconate (SrZr0₃) from zirconium oxide (ZrO₂) and strontium oxide (SrO) in the form of the decomposition product of SrCO₃ was measured using quantitative x-ray diffraction for mineralogical analysis. It was found to most nearly follow the Zhuravlev-Lesokhin-Tempel' man rate equation. The rate of decomposition of strontium carbonate was found to be more rapid than the rate of formation of strontium zirconate such that for the most part strontium oxide is …

A Study Of Porous Membrane Evaporation For Desalination In A Flow System, Jing Ming Lee

Masters Theses

"The purpose of this investigation was to study the simultaneous mass and heat transfer mechanism in evaporation through a porous membrane with a non-wettable surface. Such water repellent membranes permit the passage of water vapor, but not liquid water. The investigation concerned the mass transfer rate through the membrane pores with flow on one or both sides of the membrane. The water-repellent membrane separated a hot salt solution from the fresh water, and a copper sheet separated the fresh water from a cold salt solution. A three-channel evaporator-condenser was used, and the membrane consisted of glass fiber paper treated with …

Investigation Of Thermal Resistance At The Interface Of Dissimilar And Similar Metals, Ching-Liang Lin

Masters Theses

"Experiments have been conducted to investigate the resistance and the effect of the directional heat flow at the interface of metals in contact. The test specimens were cylinders, axially aligned and dead weight loaded. Specimen materials were aluminum, bronze, and steel. The tests were conducted at environment pressures of 5x10⁻⁵ Torr. or less. The dead weight load was kept at 10 lbs. for all tests and the surface roughness for all specimens was from 6 to 8x10⁻⁶ inch. The results of the investigation reveal that the resistance to heat flow at the interface of metals decreases as the interface temperature …

Constant Horizontal Force Machining Through Flash Welded Steel Bars Of Varying Hardness, Donald Naeger

Masters Theses

"The purpose of this experiment was to determine the effect of a constant horizontal force applied to the carriage of a lathe as it turned a piece of stock which consisted of two steel bars, of different hardness, flash welded together. This experiment was performed on a lathe to which a pulley system with a mechanical advantage of six was attached to the carriage. The strain on the tool was measured both in the horizontal and vertical directions by a tool dynamometer on which eight strain gages were mounted. The strain gages were calibrated on a Tinius-Olsen testing machine. The …