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A Mathematical Model For The Neutron Dependence Of Neutral Base Region Recombination, Jonas Bereisa Jr.

Masters Theses

"A discrete, deterministic, mathematical model is developed for the neutral bulk base region of graded base devices which accounts for both the effects of recombination and the built-in electric field in the bulk base region at low, intermediate, and moderate current/injection levels. This model is applied to a study of neutron radiation effects in double diffused silicon transistors. Exact expressions are developed for the injected emitter, base and collector currents, the base recombination term, and the ratio of base current increase to collector current decrease as functions of device geometry, impurity profile, and neutron fluence. Neutron-induced current gain degradation is …

Influence Of Film Thickness On The Performance Of Solid Lubricants, Sunil Vishwanath Mahale

Masters Theses

"The object of this investigation was to determine the effect of lubricant film thickness on the coefficient of friction and on the wear life of solid lubricants. Bonded molybdenum disulphide and bonded graphite were the lubricants tested. Dow Corning's LFW-1 and Falex lubricant tester were the two machines used for testing these lubricants. The lubricants were sprayed on the specimen surface. Pretreatment, spraying and curlng were done according to standard or manufacturer's recommended procedures. During the entire research, the procedure for experimentation was followed according to ASTM No. 2625 on Falex and CRC recommendations on LFW-1 machine. It was found …

Effect Of Third Components On Drag Reduction In Aluminum Soap-Hydrocarbon Systems, Kun-Chieh Lee

Masters Theses

"The effect of additives, aging, shear and peptizing agents on the drag reducing abilities of aluminum disoaptoluene solutions prepared at room temperature were studied. Viscosity measurements were used as a primary test to select effective additives. Medium strong organic bases were found to be useful as they speed up the dissolution of slow dissolving aluminum dioctoate soap and form large micelle structures. These peptizers are not effective with aluminum distearate which is very hard to dissolve in toluene at room temperature. Turbulent flow pressure drop measurements at various aging times were made for solutions of 0.1 per cent aluminum dioleate …

Imperfections In The Ag-In System (Alpha-Phase) And Lattice Parameters Of Cadmium Oxide, Prafulla Maganlal Vora

Masters Theses

"This thesis has been divided into two parts, namely, "Imperfections in the Ag-In System (Alpha-Phase)" and "Lattice Parameters of Cadmium Oxide." Imperfections in the Ag-In System (Alpha-Phase): It can be shown -- as in the case of the Cu-In α solid solutions -- that during quenching from the liquid state, strains are produced by the quenching process and, in addition, vacancies are quenched-in, in the Ag-In α-solid solutions. The number of vacancies present, measured by the decreased density of the alloys, is proportional to the indium content up to the solid-solubility limit. Upon heat treatment of the alloys, the thermal …

The Possible Correlation Of Carcinogenic Activity With Electronic Structure Of Benz(A)Anthracene, Patricia Joan Blair

Masters Theses

"The electronic structure of benz(a)anthracene based on the sigma and pi electrons was predicted by the modified intermediate neglect of differential overlap (MINDO) molecular orbital method and compared with the pi electronic structure determined by the Pople method. The crystalline molecular structure was used for both methods. The Pople calculation was also done on the aromatic molecular structure and a combination structure which assumed the bond lengths of the crystal structure and the bond angles of the aromatic structure. Chemical properties predicted by the MINDO and POPLE electronic structures were compared; the MINDO results provided the best agreement with experimental …

Interface Thermal Conductance With Metal Screens As Interstitial Material, William Edward Stewart Jr.

Masters Theses

"This thesis reports the results of an experimental investigation to determine the thermal conductance at the interface of metal specimens separated by wire mesh. Sets of metal specimens of copper, 2024-T4 aluminum, and 304 stainless steel were used. The specimens were cylindrical, axially aligned, and hydraulically loaded. All tests were conducted in an air environment. Pressure applied to the specimens ranged from 50 to 500 psig. Surface roughness of the interfaces varied from 5 to 20 micro inches. The wire mesh separators were of 304 stainless steel in 20, 30, 40, and 50 mesh. Results of the experiments show that: …

Transient Response Of A Vibration Isolation System, Hemendra Shantilal Acharya

Masters Theses

"A practical procedure for investigating the performance of a vibration isolation system under transient conditions is presented. For this investigation, an induction motor with an unbalanced rotor is studied during the period when it accelerates to its operating speed from rest. Using Newton's second law of motion, equations of motion are derived, first neglecting and then considering the effect of "inertia torque". This torque is produced by the inertia force resulting from vertical acceleration of the unbalanced mass. The equations are solved on a digital computer using the Runge-Kutta method of order 4. The results obtained are compared with those …

Measurement Of The Surface Energy Of Rock By The Three-Point Bending Of Notched Beams, John Walter Corwine

Masters Theses

"In this investigation, the surface energy of a medium-grained igneous rock (Barre granite) was measured by breaking small, notched beams in bending. The technique was adapted from fracture toughness tests that have been used with metals and ceramics. The equations used for the calculation of surface energy were derived from several writers' equations for the stress intensity at the end of a notch in a beam subject to bending. Beam thickness, notch width and mineral occurring at the notch tip were evaluated for their influence on the calculated values of surface energy. The surface energy values obtained were used in …

The Assignment Problem And A Suboptimal Solution Technique, William Barry Gregory

Masters Theses

"A technique is presented which finds a fast suboptimal solution to the assignment problem. This same technique is then applied to two large dynamic programming problems for which the optimal solution is not known. These examples illustrate how easily this technique can be applied and that it is better than most optimizing techniques because it is fast, cheap and only minor hand calculations are needed. The effect of different initial solutions and their value are compared and it is found that the initial solution is not as significant in a suboptimal technique as in an optimizing technique. The initial solution …

Vibration Of A Rotating Cantilever Beam With An Independently Rotating Disk On The Free End, Darrell Blaine Crimmins

Masters Theses

"This thesis provides a vibration analysis of a rotating cantilever beam with an independently rotating thin circular disk on the free end. The exact differential equations of the system as defined by classical Bernoulli-Euler beam theory are written using the methods of the calculus of variations. The exact equations are not solved, but two different approximations are found by assuming a cubic polynomial deflection curve and applying the equation of Lagrange. The solutions are restricted to small deflections of the beam and a shaft stiffness which permits a deflection in only a single plane. Nonlinear differential equations result in the …

Failure Of Lined And Unlined Small-Scale Cavities In Rock-Like Materials, Seung-Ki Yang

Masters Theses

"The strain conditions around statically loaded circular openings in rock-like materials and corresponding cavity-wall displacements were determined experimentally with resistance strain gages. The models were fabricated with lined and unlined openings simulating underground tunnels. Tests were performed with models of two different materials in plane stress and plane strain. Rock-like materials were designed and the strain gages were embedded at selected points within each model. The models often failed by tensile splitting through the opening early in the loading cycle causing the strains at certain points to deviate considerably from the theoretical values. Tangential strains on the vertical axis were …

Use Of Waste Glass As Asphaltic Concrete Aggregate, Charles Wayne Foster

Masters Theses

"The problem of solid waste disposal increases each year, with the annual growth in quantity of solid waste making the present means of disposal even more inadequate. Recycling of solid waste materials is an increasingly popular approach to the disposal problem. The glass component of solid waste is a very promising candidate for recycling, and this investigation studies the possibility of using waste glass as an aggregate for bituminous concrete mixtures. Objectives of this research were to determine whether a glass-asphalt mixture could be designed to meet the Marshall design criteria specified by The Asphalt Institute, to study the amount …

Multi-Stage Shear Testing Of A Cohesionless Soil, Robert Clyde Gullic

Masters Theses

"The multi-stage test is a procedure by which a soil's shear strength parameters can be evaluated by the use of a single sample of the material. The object of the investigation is to evaluate to what extent multi-stage testing can be used on a cohesionless material. Three types of tests, using conventional and multi-stage procedures are evaluated. They are: direct shear/consolidated drained, triaxial compression/consolidated drained and triaxial compression/consolidated undrained shear tests. It was found that multi-stage testing can easily be performed and the shear strength parameter theta_f obtained from these tests are in good agreement with those obtained from …

Parameters Effecting The Dynamic Properties Of A Saturated Cohesive Soil Tested In Cyclical Simple Shear, William Kenneth Andrew V

Masters Theses

"Cyclical simple shear tests were performed on block samples of a remolded clay mixture of 3 parts kaolinite to 1 part of bentonite mixed at 110% water content. The samples had base sizes of 8x8, 4x4, and 2x2 inches square and heights of 1, 2, 4, and 8 inches. The simple shear tests were performed by using a predetermined sinusoidal displacement, at frequencies of 1, 2, and 5 hertz. The shear modulus which was normalized by dividing it by the shear strength, and the hysteretic damping factor which was expressed as the percent of critical damping, were evaluated from a …

A Study Of The Oxygen Exchange Between Chromate Ion And Water, James Hsiao-Hsin Chiang

Masters Theses

"The kinetics of the isotopic exchange reaction between O¹⁸-enriched chromate ion and solvent water have been measured as a function of pH and chromate ion concentration. The exchange kinetics can be explained in terms of the dimerization equilibria HCrO_4̄ + Cr₂O[subscript 7 with double dash above] [double arrows] Cr₂O[subscript 7 with double dash above] + OH⁻ and 2HCrO_4̄ [double arrows] Cr₂O[subscript 7 with double dash above] + H₂O except at high pH, where it is independent of pH. Rate constants at 30ºC for the reactions of the dimerization equilibria and the first order reaction at the high pH …

Evaluation Of The Carbon Adsorption Method With Parallel Solvent Extraction Studies, Stanley Kent Wagher

Masters Theses

"In spite of the importance of the carbon adsorption method (CAM) in determining drinking water quality and its wide use in research and plant control studies, little work has been undertaken to quantitatively and qualitatively evaluate the method, especially under field conditions. This investigation was, therefore, undertaken in order to develop a test system consisting of equipment and procedures which would make possible the field evaluation of the carbon adsorption method by parallel solvent extraction studies, and to employ this system in preliminary field investigations to establish guidelines for the experimental conditions required for its effective application. The test system …

A Transient Method Of Negligible Internal Thermal Resistance For Determining Thermal Contact Conductance In A Vacuum, Richard Chuka Oboka

Masters Theses

"A transient method for experimentally determining the interface conductance between metallic surfaces in contact is developed. The method applies the theory of negligible internal thermal resistance of one of the materials which form the interface. The method is applicable when the interface conductance is very low, a situation which exists when low conductance interstitial materials are used between contacting surfaces for purposes of thermal isolation. In this investigation, stainless steel wire screens of 10 and 100 mesh were used as interstitial materials between aluminum surfaces in a vacuum environment of 10⁻⁵ to 10⁻⁶ Torr. The interface pressure ranged from 40 …

An Analysis Of A Quadrature Double-Sideband/Frequency Modulated Communication System, Denny Ray Townson

Masters Theses

"A QDSB/FM communication system is analyzed with emphasis placed on the QDSB demodulation process and the AGC action in the FM transmitter. The effect of noise in both the pilot and message signals is investigated. The detection gain and mean square error is calculated for the QDSB baseband demodulation process. The mean square error is also evaluated for the QDSB/FM system. The AGC circuit is simulated on a digital computer. Errors introduced into the AGC system are analyzed with emphasis placed on nonlinear gain functions for the voltage controlled amplifier"--Abstract, page ii.

Simulation Of A Gas Storage Reservoir With Leakage By A Two-Dimensional Layered Mathematical Model, Steven William Ohnimus

Doctoral Dissertations

"A generalized mathematical model was developed for two-dimensional compressible fluid flow accounting for the effects of relative permeability capillary pressure, and gravity drainage in addition to the reservoir properties of rock heterogenity and reservoir geometry. The generalized model developed was applied to an aquifer gas storage reservoir in which vertical leakage occurred from the main reservoir to two adjacent overlaying zones. The experimental results of Thomas, et al. were utilized in applying the model to gas storage injection/withdrawal periods yielding reasonable results for the three layers"--Abstract, page ii.

Iddap -- Interactive Computer Assistance For Creative Digital Design, Richard Franklin Crall

Doctoral Dissertations

"A new computer-aided design program to assist in the initial phases of logical design is described. The program, intended for use via an on-line remote terminal, will allow the designer to study and experiment with design alternatives during the initial creative design phases. An ALGOL-like language is used for specifying the system being designed. In addition to simulating the design, the program allows the user to perform on-line design changes, reorganize data and generate timing diagram information"--Abstract, page ii.

Electrode Reactions In Zinc Electrolysis, Ernest R. Cole

Doctoral Dissertations

"The effects of temperatures from 0°C to 50°C and current densities from 10 asf to 200 asf on the current efficiency in the electrolysis of pure zinc sulfate solutions (65 gpl Zn⁺⁺ - 200 gpl H₂SO₄) were determined. Pure platinum and platinum coated titanium anodes were used with an aluminum cathode. Platinum anodes were not inert at certain combinations of temperature and current density, and platinum acted as a low overvoltage impurity causing resolution of the cathode deposit. Orientation of the zinc deposits was found to vary with temperature and to have a distinct relationship to current efficiency. Preconditioning of …

An Experimental And Theoretical Study Of The Nucleation Of Water Vapor On Ions In Helium And Argon, Daniel R. White

Doctoral Dissertations

"The nucleation of water vapor on ions in atmospheres of helium and argon was studied using an expansion type cloud chamber. Separation of the positive and negative ions was achieved so that the nucleation could be studied as a function of both the sign of the ionic charge and the supersaturation. A semiphenominological theory was developed as an extension of the classical theory to include the effects of the ionic charge on the nucleation process. The theoretical model of the prenucleation embryo was assumed to possess an oriented dipole surface layer with the direction of orientation dependent on the sign …

Penetration In Granite By Shaped Charge Liners Of Various Metals, Hemendra Nath Kalia

Doctoral Dissertations

"The penetration in Missouri red granite by cylindrical charges with metal liners of aluminum 2011 (T-3), aluminum 7075 (T-6), yellow brass, monel, maraging steel (vascomax 250), and copper was measured. Metals having high ductility and moderate compressive strength penetrated deeper than high strength maraging steel. Aluminum required a greater standoff for optimum penetration than the other metal liners tested. Preliminary metallographic studies of the liner metals and slugs showed that the grains had elongated along the slug axis. The metals containing zinc formed very small or no slugs. The granite grains were highly fractured. The holes were discolored and coated …

The Oxidation Kinetics Of Liquid Lead And Lead Alloys, Thomas Edward Weyand

Doctoral Dissertations

"Liquid lead and lead-silver alloys were investigated to determine the rates and products of oxidation in pure oxygen at temperatures of 350 to 600°C. The kinetic data were determined using a Cahn electro-balance. Liquid lead was found to follow a cubic rate of oxidation between 350 and 400°C. A parabolic rate was found at temperatures above 400°C. 0.496% silver and 2.258% silver alloys followed a cubic rate of oxidation from 350 to 550°C and tended to approach a parabolic rate of oxidation above this temperature. Silver additions were found to increase the rate of oxidation as compared to the pure …

Use Of The Turbulence Kinetic Energy Equation In Prediction Of Nonequilibrium Turbulent Boundary Layers, William Madison Byrne Jr.

Doctoral Dissertations

"A differential method is proposed for the prediction of a broad range of turbulent boundary layers of engineering and scientific interest. A digital computer program is presented which is applicable to boundary layers with positive, negative, and zero pressure gradient in the main-stream direction as well as boundary layers with suction, blowing or zero mass addition at the wall. The turbulence kinetic energy equation is solved simultaneously with the longitudinal momentum and continuity equations to provide an independent means for determining the effective viscosity which makes allowance for "history" effects in the flow. It is shown that the prediction method …

Higher Space Mode Analysis Of A Large Cylindrical Pulsed H₂O System, Harold David Hollis

Doctoral Dissertations

"By utilizing a geometrically centered pulsed source internal to a large (B²_g) ≈ 0.002) cylindrical H₂O system, the neutron flux was measured as a function of position and time. A least square fit of the data yielded the fundamental and five higher decay constants and amplitudes of the thermal neutron flux. Symmetrical and enhanced neutron densities were obtained as a result of the internal source. Long waiting times were unnecessary and data acquisition was accelerated.

The decay constants were found to be independent of position, pulse width, counting time and rates, method of normalization, or waiting time. …

Effect Of Axial Dispersion On Interphase Mass Transfer In Packed Absorption Columns, Virendra Kumar Mathur

Doctoral Dissertations

"A steady state approach was followed in this investigation to determine the effects of liquid and gas flow rates, packing size and packing height on the interphase mass transfer coefficient and gas phase axial mixing Peclet numbers. Experiments were performed on the absorption of carbon dioxide from a mixture of carbon dioxide and nitrogen in a packed column. Absorption was performed using 1/4, 3/8 and l/2 inch Raschig rings, with a packing height of 3 feet and also using 3/8 inch Raschig rings with a packing height of 5 feet. The liquid and gas flow ranges used were 2865 to …

Model-Referenced Adaptive Control Of Plants With Noise And Inaccessible State Vector, Donald James Schooley

Doctoral Dissertations

"The problems of process noise, measurement noise, and inaccessible process state vector in the model-referenced system of Shackcloth-Butchart-Parks (SBP) are investigated. Since the system no longer possesses a static equilibrium point, the concept of asymptotic stability does not apply. However, by using Liapunov-like ideas, the error between the plant (process plus controller) and the model is shown to enter a region about the origin if certain bounds are known. A possible technique for reducing the size of this region is to feedback a function of the error into the plant's input. Several methods of circumventing the inaccessible state vector problem …

Synthesis Heuristics For Large Asynchronous Sequential Circuits, Robert Judson Smith

Doctoral Dissertations

"Many well-known synthesis procedures for asynchronous sequential circuits produce minimal or near-minimal results, but are practical only for very small problems. These algorithms become unwieldy when applied to "large" circuits with, for example, three or more input variables and twenty or more internal states. New heuristic procedures are described which permit the synthesis of very large machines. Although the resulting designs are generally not minimal, the heuristics are able to produce near-minimal solutions orders of magnitude more rapidly than the minimal algorithms. A method for specifying sequential circuit behavior is presented. Input-output sequences define submachines or modules. When properly interconnected, …

The Effects Of Magnetic Fields Upon The Steady State And Short Circuit Performance Of Low Voltage Multi-Link Fuses, John Thomas Schultz

Masters Theses

"The steady state and short circuit performance of multi-link fuses is investigated, as it is affected by the magnetic field of the nearby returning current and the current flowing in the fuse itself. The fuses investigated are low voltage (600 volts or less), multi-link fuses with ratings between 400 and 4000 amperes. The effects of the above mentioned magnetic fields upon the steady state current distribution within the fuse and upon the mechanical forces acting on the individual fuse links are calculated, while the effects of close proximity of the returning current upon short circuit fuse performance are shown by …