Digital Commons Network^™

Grain Boundary Diffusion In Ionic Crystals, Kulwant Singh Sabharwal

Doctoral Dissertations

"The diffusion of ¹³¹I in single crystals and along the tilt grain boundaries of pure and calcium chloride doped (142±5 ppm) bicrystals of sodium chloride, grown by Czochralski technique, was investigated using a microtome sectioning technique. Results on bulk diffusion in pure NaCl agree well with the results of earlier investigators and are represented by the D=(504 cm²/sec)exp (-2.27 ev/kT). Enhanced diffusion of ¹³¹I is observed along the grain boundaries and the presence of the dopant lowers the grain boundary diffusivity over the entire temperature range of 430ºC - 570ºC studied in the present investigation. Thermal activation and electrical polarization …

An Exact Analysis Of Two-Dimensional Radiative Transfer In An Absorbing And Emitting Gray Medium, William F. Breig

Doctoral Dissertations

"The exact formulations for the radiative flux and the emissive power are presented for a two-dimensional, finite, planar, absorbing and emitting, gray medium in radiative equilibrium. Exact expressions are obtained for the medium subjected to the following types of boundary conditions: (1) cosine varying diffuse, (2) cosine varying collimated, (3) constant temperature strip, and (4) the strip illuminated by a uniform collimated flux. The solutions for the physically unrealistic cosine varying models are used to construct the solutions for the more practical finite strip models. The two-dimensional equations are reduced to one-dimensional equations by the method of separation of variables. …

The Use Of Shaped Explosive Charges To Investigate Permeability, Penetration, And Fracture Formation In Coal, Dolomite And Plexiglas, Calvin J. Konya

Doctoral Dissertations

"The concentration of methane gas which exists in the exhaust air from a coal mine is critical. It can be controlled by dilution of the gas with fresh air or by the regulation of the rate of methane emission into the mine workings. Degasification techniques which control the emission rate are currently being developed. The use of shaped charges to initiate fractures in coal and increase the gas flow rate was the object of this research. The three areas of investigation were: 1) permeability changes in coal models after fracturing with shaped charge jets, 2) fracture formation in coal and …

The Analysis Of A Subsonic Jet Issuing Perpendicular To A Freestream Flow From A Flat Plate And A Body Of Revolution, Donald R. Haberman

Mechanical & Aerospace Engineering Theses & Dissertations

An investigation was undertaken to determine the nature of the pressure region around a jet issuing perpendicular to a free stream flow from a flat plate and a cylindrical surface, and to determine the forces which resulted from such a pressure region. It was also attempted to develop an empirical relation to enable the prediction of surface pressure regions from known physical parameters.

The jet was exhausted from a 0.375 inch nozzle perpendicular to a free stream flow of about 90 ft./sec. The flow rate of the jet was then varied to give three free stream to jet velocity ratios …

Secondary Techniques For Increasing Fault Coverage Of Fault Detection Test Sequences For Asynchronous Sequential Networks, Lewis Ronald Hoover

Doctoral Dissertations

"The generation of fault detection sequences for asynchronous sequential networks is considered here. Several techniques exist for the generation of fault detection sequences on combinational and clocked sequential networks. Although these techniques provide closed solutions for combinational and clocked networks, they meet with much less success when used as strategies on asynchronous networks. It is presently assumed that the general asynchronous problem defies closed solution. For this reason, a secondary procedure is presented here to facilitate increased fault coverage by a given fault detection test sequence. This procedure is successful on all types of logic networks but is, perhaps, most …

An Analytical Study Of A Confined Viscous Vortex, David Edward Crow

Doctoral Dissertations

"A composite solution for the flow field of a three dimensional, incompressible laminar, viscous vortex confined inside a conical converging nozzle is presented. This model is used to study the strong mainstream boundary layer interaction that occurs in confined vortex flows. The confined vortex flow field is divided into mainstream and boundary layer regions. A particular class of solutions of the general equations of motion is used to represent the vortex flow in the mainstream region. That is, the tangential velocity in the mainstream region is assumed to be of the form W = T(e)/R. Velocity and pressure profiles from …

Synthesis And Characterization Of Poly-(P-Phenylene Pyromellitamic Acid), Constantine William Tsimpris

Doctoral Dissertations

"Poly-(p-phenylenepyromellitamic acid)s have been synthesized over the weight average molecular weight range from 8,000 to 22,000 by reaction of pyromellitic dianhydride and p-phenylenediamine in dimethylformamide. The polymers were recovered as amorphous yellow powders having planar dimensions of 3-4 x 1-2 µm with thicknesses of 0.1-0.2 µm and contained 20-30% associated dimethylformamide. Consumption of reactants and attainment of the ultimate molecular weight of the polymer was found to occur within one minute. Thermogravimetry of the solid poly(amic acid)s was used in a method developed to determine the amount of associated dimethylformamide, to study the cyclization of poly(amic acid) to polyimide, and …

The Effect Of Impurities And Additives On The Electrowinning Of Zinc, Haruhisa Fukubayashi

Doctoral Dissertations

"The effect of various impurities, commonly found in zinc electro-winning solutions, on the surface morphology of deposited zinc was investigated. Individual additions of the impurities Al, Ag, Cd, Co, Cr, Cu, Ge, Mn, Ni, Sb, Sn, Ti, PbO₂ , PbSO₄, and HCl were studied. In a few cases additives of animal glue, gum arabic, and Na₂SiO₃, were used individually or in combination, to determine their effect on the surface structure of the deposited zinc. Comparisons were then made with deposits from a pure electrolyte consisting of H₂SO₄ and Zn⁺², 200 and 65 g/l, respectively. The zinc was deposited on a …

The Structural Behavior Of Cold-Formed Steel Members With Perforated Elements, Charles S. Davis

Doctoral Dissertations

"Analytical and experimental investigations have been conducted to study the influence of perforations on the structural behavior of cold-formed steel structural members. Since in many cases, the load-carrying capacity of cold-formed steel members depends on the buckling behavior of individual component elements, emphasis has been concentrated on the study of the instability and post-buckling strength of perforated elements. In this investigation, the buckling loads and post-buckling strength of stiffened and unstiffened compression elements having single circular and square holes have been studied analytically by using the finite element method. The effects of different holes on the buckling coefficient have been …

A Hardware And Software Interface Between A Magnetic Tape Unit And A Nova Mini-Computer, Thomas Dean Steury

Masters Theses

"This thesis is concerned with the general operation of the Kennedy Model 1400R incremental write/continuous read magnetic tape unit and the hardware design and software implementation needed to make it compatible for use with the Data General Nova 800 mini-computer.

The hardware design was developed around a General Purpose Interface Board which provides a standard set of logic needed for interfacing any external device to the Nova. The hardware consists of decode networks, mode selection networks, and I/0 timing networks. Special circuits needed to implement the hardware design and perform voltage conversions between the tape unit and the Nova computer …

Preliminary Studies With A Variable Transfer Composite Polymer Membrane., Samuel Walter Dortch

Masters Theses

"A preliminary study was done to determine the feasibility of using a compressed fibrous teflon (PTFE) silicone polymer membrane in extracorporeal oxygenation devices. A series of composite membranes were fabricated, using different concentrations of a dimethyl silicone polymer dissolved in petroleum ether, to give membranes having variable oxygen transfer properties. A gas-gas system was chosen to obtain the necessary transfer data. Data were obtained by transferring pure oxygen through the membranes into a mixture of 47 mole percent oxygen and 53 mole percent carbon dioxide. All analyses were obtained by chromatographic techniques. The results of these experiments show that membranes …

An Accurate Digital Instrument To Measure Reactor Period, Ernest Wayne Scott

Masters Theses

"At facilities having a research-training reactor, such as the University of Missouri-Rolla Reactor (UMRR), one finds it necessary to perform a large number of rod calibrations during the course of the year. In practice rod worths are determined by measuring the reactor period created by an incremental withdrawal of the rod under calibration. Period is then related to reactivity thru the use of a publication such as the AEC publication, TID-4500.

This frequent measurement of period makes it desirable to have a simple, automatic and accurate method to make such measurements. At UMRR we have designed, constructed and installed such …

Performance Comparison Of Receivers Designed To Combat Intersymbol Interference Due To Specular Multipath, George H. Smith

Masters Theses

"Bit error probabilities for biphase transmission have been computed for a known two-component multipath channel with a variety of suboptimum receivers. Performance curves are presented for each receiver, and the relative performance is summarized. Degradation due to imperfect channel knowledge is calculated, and the feasibility of countering this interference with these specially designed receivers is discussed"--Abstract, page ii.

Concentration By Sorting : Feasibility Determination By Radial Distribution Analysis, Robert M. Doerr

Masters Theses

"A method was developed for determining certain factors for assessing the feasibility of sorting fragments of an inhomogeneous solid to concentrate a species. These factors are the typical size of zones in which the grade exceeds a selected value, and the recovery potentially achievable by sorting fragments of such size"--Abstract, page iii.

Analysis And Measurement Of A Zener Diode Voltage-Reference, Armond C. Maxeiner

Masters Theses

"Output voltage sensitivity equations are derived for a zener voltage-reference circuit. The circuit consists of a DC-DC converter, a voltage-resistor current generator, and a zener diode. The performance of the voltage-reference is calculated using the sensitivity equations and compared to measurement data taken from a laboratory model of the circuit. The results are in reasonable agreement.

It was concluded that with careful selection of components, two of three major sources of error can be predicted and controlled; these are changes due to input voltage and changes due to temperature. The third, changes due to time, requires calibration against a voltage …

A Study Of Plane Wave Filter Analysis With Flow, Thomas Valle Huber

Masters Theses

"The purpose of this investigation is to determine the effect of slow steady flow on the reflection and transmission characteristics of acoustic filters.

A standing wave tube and transmission tube apparatus, designed and built by a previous investigator, was modified to accept slow steady flow. Reflection characteristics were determined from measurements made on the inlet side of the filters investigated. These data along with measurements taken with the transmission tube apparatus were used to determine transmission characteristics. The calculations were simplified by terminating the filters anechoically. The filters used in this investigation were an expansion chamber, an automobile type muffler …

A Sensitive Temperature Measuring System, Larry Dean Morris

Masters Theses

"A sensitive temperature measuring system, providing an analog output proportional to sensor temperature, has been designed for use in the wall temperature control system of a cloud simulation chamber. A platinum resistance element is the sensor, and a precision wirewound resistor is the reference in a bridge circuit which uses four low cost operational amplifiers arranged to provide two precision 1000 Hz current sources. Problems with an initial bridge amplifier design were corrected in the final design by the use of a low Q bandpass amplifier for the bridge signal followed by a phase detector and an output low pass …

Digital Registration Of Stereo Images Using The Fast Fourier Transform, Victor Francis Wilreker Jr.

Masters Theses

"The exact alignment of multispectral imagery is a requirement of any image classification system. This investigation develops a system of programs which result in a technique that corrects for the translational and rotational misalignment of two images. Rotational and translational components are determined by using the fast Fourier transform to find the points of maximum correlation between the two images. The registration of two equal but misaligned boxes is given as an example of how the transform technique is used in correlating the images. The results of registering two digitized images that were obtained by scanning a pair of color …

Computer-Aided Circuit Optimization Including The Adjoint Method Of Calculating Network Sensitivities, John Walter Olson

Masters Theses

"A complete discuss ion of the optimization of a circuit, including modeling and programming difficulties encountered, is presented. A three transistor bandpass filter is used in order to study various methods of optimization. The adjoint method of calculating the network error gradient vector is compared to the perturbation method. The adjoint method proves to have decided advantages over the other method. A generalized computer program is presented to carry out the Fletcher-Powell optimization algorithm with specialized subroutines which include a network equation solver and both methods of finding the gradient vector. The program proved very effective in realizing a desired …

A Study Of Right Turn On Red At Signalized Intersections, Ronald Duane Rains

Masters Theses

"Traffic engineers have discussed the controversial subject of allowing drivers to make a right-turn-on-red (R.T.O.R.) for many years. There have been many strong points given for and against allowing this movement.

Within this paper R.T.O.R. is discussed and conclusions are drawn for a research of literature and questionnaire survey.

Questionnaires were sent to ninety-three cities and all fifty states. Many valuable unwritten facts and opinions were received from the seventy city and thirty-six state traffic engineers that completed and returned the questionnaires.

It was determined that 63.8% of the states replying and 64.3% of the cities are presently utilizing R.T.O.R. …

Computer Simulation Of The Primary Recoil Spectra And Damage Cross Section Of Fe₃Al Using Endf/B Ii Data, Daniel Willard Smith

Masters Theses

"A computer program, using Evaluated Nuclear Data File (ENDF/B II) information, was used to develop energy-exchange kernels which delineate the energy transfer probabilities between neutrons and Fe₃Al lattice atoms. The kernels combine all available information on elastic and inelastic scattering contained in the ENDF/B II data.

The computer program used to generate the primary recoil spectra is SAKI, a modified version of RICE (1). SAKI is designed to calculate energy-exchange probabilities in any binary alloy as well as damage cross sections and optimum cutoff energies for use in comparing displacement effects in different reactor spectra."--Abstract, page ii.

Fitting Discrete Probabilistic Frequency Distributions To Disturbed Traffic Flow At An Unsignalized Urban Intersection, Horst Walter Kaminsky

Masters Theses

"Traffic variables, such as volume, speed, gaps and lags, and headways can be described by probability distributions. In this study vehicle arrivals from three directions have been recorded at a four-leg, right-angled, at-grade intersection in Rolla, Missouri, and statistically analyzed. Two distinct probabilistic statistical concepts were used, the continuous (gap) and discrete (counting) distribution. The negative exponential distribution is discussed briefly, whereas the applicability of discrete statistical models for the traffic situation selected is elaborated in detail.

The purpose of this research was to investigate the impairment and distortion that various interferences such as upstream traffic lights, bottlenecks or other …

Data Compression Design Considerations For Airborne Test Vehicles, Kenneth Carlyle Pittman

Masters Theses

"The design goals for a data compression system are developed using previous studies as a cornerstone. Sampling theory is touched on with qualitative coverage of its effects. Consideration is given to various methods of data compression with the advantages and disadvantages of each noted. The requirement for buffering is discussed along with various methods that may be employed to achieve specific buffering goals. The impact of data reconstruction and how it may affect the choice of compression techniques is briefly covered. Selected compression algorithms and ways of increasing system effectiveness through alterations to their basic structures are described in detail. …

A Study Of Fmfb Demodulator Operation In The Presence Of Radio Frequency Interference And Gaussian Noise, Terry D. Wormington

Masters Theses

"A digital computer model of an FMFB demodulator has been used to study the effects of radio frequency interference on the detection of a sinusoidally modulated carrier. The effectiveness of selecting the feedback factor to suppress the interference for three values of modulation index is investigated. Also, the required IF bandwidth for the minimization of the mean-square error of the loop output between a signal corrupted by interference and the same signal without interference was investigated. More work is required before the effects of Gaussian noise plus interference on loop operation can be ascertained"--Abstract, page ii.

Sensitivity Analysis In Active Rc Bandpass Circuits, Robert Bentzinger

Masters Theses

"This thesis is concerned with the analysis and cataloguing of sensitivity functions of some selected active RC bandpass networks. The sensitivity functions of primary interest are the sensitivities of the quantities ω_o and Q with respect to changes in the element values of each circuit.

An introduction is provided to give background information on how each circuit is realized. Each circuit is then analyzed and the pertinent sensitivity functions catalogued. Some comments are made as to the approximations which are involved in several of the realizations and the validity of any sensitivity analysis made on these approximate realizations. The …

Thermal Stresses And Movements In Bridges, Joseph Charles Reynolds

Masters Theses

"A state of the art regarding the thermal behavior of bridges and considerations to be given to the resultant thermal effects is presented. The results of studies related to the thermal effects on bridges are reviewed. Studies attempting to relate environmental factors to bridge temperatures, and subsequently to bridge movements and stresses, indicate that the task is extremely complex. Some correlation has been made between equations predicting bridge temperatures and movements based on weather bureau records. However, further research is needed to evaluate the effects of factors other than temperature, such as creep, shrinkage, and humidity on bridge movements and …

An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja

Masters Theses

"Fluidics, the new control technique finds its use amongst the conventional electronics and pneumatics due to some of its impressive features. Selected literature about bistable and proportional amplifiers has been presented for better understanding of the element behavior. Sensors; typical applications of fluidics have been described separately. An air flow velocity sensor has been set-up. Basically it consists of a cylinder placed across the air flow that sheds vortices in the wake due to 'Von Karman Vortex Street' phenomenon. The frequency of vortices gives a measure of velocity. The velocities obtained from the sensor have been compared to the ones …

Phase Transformations In The System Zro₂-Cao, Damri Sukhotanang

Masters Theses

"Thermal expansion, thermal hysteresis, and the monoclinic tetragonal phase transformation of ZrO₂ have been studied with high temperature x-ray diffractometry. The initial transformation temperature in pure ZrO₂, on heating, is about 1150ºC. The transformation occurs over a 100ºC temperature range and thermal hysteresis occurs on heating and cooling. The mechanism of the transformation is related to preferred vibrational modes of atoms on the A_O -C_O plane of the monoclinic structure. Because the monoclinic B_O axis is parallel with the tetragonal [110] axis, structural relationships can be seen to be a controlling factor in the transformation. Initiation of …

A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah

Masters Theses

"Four Liapunov functions used in stability studies are compared for accuracy on an eight machine power system. This comparison is made to determine which function is best in multimachine stability applications. Morgan's Estimating Technique is used to estimate when the Liapunov function would exceed its maximum value and thus to predict the critical switching time for the system"--Abstract, page ii.

The Steady-State Response Of A Fluid-Filled Beam Near Resonance, Niranjan Jayantibhai Patel

Masters Theses

"In this report the steady-state near-resonant vibration of a hollow fluid-filled beam is considered. The energy dissipation caused by the beam-fluid interaction is approximated by introducing a viscous damping force into the Bernoulli-Euler beam equation. A theoretical expression is developed for the displacement of the hollow beam by solving this modified Bernoulli-Euler beam equation. Tests are made using a cantilevered fluid-filled box to simulate a unit of beam-fluid length. The band-width technique is used to determine the incremental viscous damping coefficient from test data. A variety of fluids are used in the box to determine the effect of the fluid …