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A Travelling-Wave Transistor Amplifier, Manit Kovintha

Masters Theses

"This thesis discusses a steady-state analysis and design of a coupled uniform travelling-wave transistor amplifier. A solution to the problem is given in closed form and a numerical method for evaluating the solution is discussed.

Practical line parameters and different terminations are used in frequency response calculations. The amplifier power gain variations due to parameter variations are considered and shown in full"--Abstract, page ii.

Mass Transfer Coefficients Determined By Simplex Optimization Techniques, Charles Ferris Callihan

Masters Theses

"The objective of this thesis is to develop a method for obtaining individual mass transfer coefficients in absorption columns. There are two assumptions which apply throughout the thesis. The first assumption is "plug flow." The second assumption is that the axial concentrations can be measured accurately enough.

The problem is approached by simulating data generated from a mathematical model of an absorption column. A response surface is defined which is a function of the individual mass transfer coefficients. The lowest point on the surface locates the individual mass transfer coefficients for the system in question.

The mathematical model of the …

Temperature Dependence Of The Formation Of An Amorphous Layer In Ion-Implanted Silicon, Gary Keith Woodward

Masters Theses

"Electron spin resonance (ESR) has been used to study the temperature dependence of the formation of an amorphous damaged layer produced by ion implantation in silicon.

Undoped silicon wafers were implanted with N⁺, Ar⁺, and Kr⁺ ions at 20 keV and dose rates less than .36 µa/cm². Implant temperatures ranged from room temperature to 250°C. ESR measurements were made at room temperature on these wafers. The only ESR signal found was that associated with amorphous silicon. The ESR signal amplitude for a given ion and temperature increased approximately linearly with dose up to …

Pollution Abatement Of Mining Effluents In The New Lead Belt Of Missouri, Walter Armando Escalera

Masters Theses

"The mining and milling effluents from the Buick Mine of the AMAX Lead Company of Missouri have produced undesirable algal growths in Strother Creek below their tailings pond. A field and laboratory study was performed to determine the characteristics of the mining and milling wastewaters, and to study the effects of heavy metals and nutrients on algal growths. Laboratory studies included: Physico-chemical analysis of the wastewater; determination of heavy metal concentrations; algal growth studies in an experimental model; and microscopic examinations of the algal growths. Field work comprised: A study of the mining and milling operations; in-plant investigations of the …

The Effect Of Gating On Soundness Of Al-Alloy Permanent Mold Castings, Dinesh Shantilal Patel

Masters Theses

"This thesis describes the step by step approach to the design of a gating system for the production of sound plate castings in permanent molds. Castings of different thicknesses were produced, utilizing various gating systems, and examined radiographically to evaluate the effectiveness of these gating systems in the production of sound castings. A gating system which allows metal to enter the mold cavity with no turbulence and which establishes proper temperature gradients in the casting will produce sound permanent mold castings"--Abstract, page ii.

Neutronics Calculations Of Two Fusion Reactor Blankets, James Edward Struve

Masters Theses

"At the present state of engineering development, the most probable fusion reactor fuel cycle will use deuterium and tritium in the reaction ²₁D + ³ ₁T → ¹₀n + ⁴₂He. This reaction is exothermic and provides 17.6 Mev of energy of which 14.1 Mev are given to the neutron. The reaction will take place in a plasma environment inside an evacuated chamber. This chamber will be surrounded by a "blanket" which will serve to transform the kinetic energy of the neutron into heat and produce tritium for subsequent use in the fuel cycle. …

Marshall Properties Of Asphaltic Concrete Containing Glass-Rich Fractions, James Joseph Schneider

Masters Theses

"The use of crushed waste glass as an aggregate in asphaltic concrete has been suggested as a means for re-using glass separated from municipal refuse. Laboratory studies and field installations have generally utilized clean glass obtained by hand sorting bottles from the other refuse and crushing them to produce a desired gradation. For this type of asphalt to be economical though, the glass fraction must be separated mechanically. For mechanically separated materials, the glass-rich fraction also contains such items as metal, bone, rubber and other non-glass materials.

The objective of the study was to determine the effects upon Marshall properties …

Sintering And Microstructure Control Of A Ferrimagnetic Mn-Zn Ferrite Spinel, Joel Keith Michel

Masters Theses

"The effect of minor additions of CaO dopant to a manganese zinc ferrite – Zn_.25Mn_.75 Fe_2.17 O_4.0 - on its grain growth and densification kinetics in air at 1250°C., 1300°C., and 1350°C. was studied. Grain growth was controlled over a range of dopant levels. At a sintering temperature of 1350°C. and time of six hours a ferrite with the smallest dopant addition was sintered to the highest density - 98% of theoretical. Under the same sintering conditions ferrites with higher dopant levels also sintered with normal growth but sintered to lower densities.

Due to discontinuous …

Stability Of Filled Cylindrical Shell Columns, Yu Wen Tsao

Masters Theses

"This experimental investigation was conducted to study the stability of filled cylindrical shell columns. Two kinds of filler materials, flower clay (florist clay) and silica sand, were investigated. The cylindrical shells were made of 2024-T3 Reynolds aluminum tubing. Uniaxial compressive loading was applied directly to the filler materials through two loading rams, one at each end of the cylinder, (no loading was applied directly to the shell). Tests for investigating the load transmitting characteristics of the filler materials were performed, and the states of the stresses existing in the cylindrical shells were then obtained.

The buckling formula for thin-walled cylindrical …

Digital Fault Calculations Of Large Systems Using Matrix Language And Generalized Equations, Saeed Abdel-Halim Khalifa

Masters Theses

"A new short circuit program has been developed for a large system. Several features have been provided to simplify handling of the system data. Various study cases are performed, efficiently, within the available computer memory. A master data bank is established from bus, feeder and transformer data. They can be modified internally to simulate various system configurations. Matrix formation is accomplished using a new sorting method and the IBM/360 Matrix Language MATLAN. A generalized set of ii ·equations have been developed and applied to calculate four types of faults.

The program consists of two phases of operations. In phase-1, input …

Break-Even Criteria For A Pulsed D-T Reactor, Kenneth Franklin Keller

Masters Theses

"To those who keep track of such things and are in a position to make predictions, it appears that the use of controlled thermonuclear reactions to economically produce electric power is well within a lifetime from now. Indeed, experiments presently being conducted are putting us closer and closer to the development and construction of demonstration fusion reactors. Understandably, the people working on such products and processes are optimistic about their results. This is as it should be if our nation is to avoid major energy shortages in the future.

Unfortunately, the tenor of this paper is pessimistic. This is not …

Use Of Radioactive Iodine Evolved Into Reactor Cooling Water To Locate Defective Fuel Elements, Carl Mozel Stroud

Masters Theses

"The relative amount of radioactive iodine evolved in reactor cooling water by each fuel element provides an excellent indication of defective cladding on fuel elements. The radioactive iodine evolved into the reactor cooling water from a defective fuel element should be higher than the average radioactive iodine evolved by other fuel elements into the cooling water by an order of magnitude or more.

Radioactive iodine with non-radioactive iodine carrier is adsorbed on DOWEX SBR resin in the iodide form. The iodide is eluted from the resin with sodium hypochlorite and extracted into carbon tetrachloride. The iodine is reduced to iodide …

A Survey Of Missouri's Water Resources Involvement, Frank R. Ellis Ii

Masters Theses

"A survey of the procedures for development of water resources in the State of Missouri reveals shortcomings in many areas. Recommended improvements include: 1) revising and publishing a statewide water plan, 2) improving methods of project evaluation and priority establishment, 3) expanding methods of citizen involvement, and 4) reorganization of state agencies and legal authority. The paper examines the history of water resource involvement by the State of Missouri, and current jurisdiction of state agencies, including procedures for review of environmental impact statements"--Abstract, page iv.

Heat Transfer Of A High Prandtl Number Oil In Laminar Flow, John Robert Lee Iii

Masters Theses

"A numerical model was developed for the purpose of studying the flow and heat transfer of a hypothetical oil in laminar flow within a horizontal pipeline. Free convection, work of compression, and axial conduction were neglected, but the fluid properties - i.e., density, specific heat, viscosity, and thermal conductivity - were allowed to vary and the effect of viscous dissipation was included in the analysis of the system.

The mathematical forms of the momentum, continuity, and energy equations require that numerical solutions be obtained with a digital computer. These numerical approximations of the partial differential equations are presented and the …

Analysis And Design For Semi-Automatic And Automatic Control Of Vehicles By Permanent Magnets, Hari K. Mehta

Masters Theses

"The analysis and design carried out in this study relates to automatic or semi-automatic lateral control of a vehicle. This is one of the three essential subsystems needed for a complete automatic control system. The other two subsystems provide longitudinal control, and intersection or lane-changing control.

The system studied employs a series of permanent magnets which have been embedded vertically in the road and spaced at an interval to be used for position reference, leading to discontinuous error signal. This system has been analyzed by classical Z-transform analysis and control models have been developed for two kinds of controls. First, …

Thermal Radiative Properties Of A Semi-Infinite Absorbing-Emitting And Isotropically Scattering Medium, Tung-Ting Lam

Masters Theses

"The development and the approximate solution to the transport equation for a semi-infinite, absorbing, and isotropically scattering medium with a refractive index other than unity is presented. The general boundary condition of diffuse and collimated incidence at the interface with emission from the medium was considered by superimposing the individual effects. In each case the apparent properties, directional and hemispherical emittance, reflectance and transmittance, were evaluated as a function of the scattering albedo and the refractive index.

An exponential kernel substitution was developed and used to obtain the approximate solution. The method was evaluated by a comparison with existing but …

Heavy Metal Concentrations In The Waters Of The Springfield Area, Missouri, Anita Louise Williams

Masters Theses

"Water samples consisting of streams, springs, lakes, deep wells, and shallow wells were collected from various locations around the Springfield area. These were analysed for concentrations of the heavy metals of lead, copper, cadmium, zinc, mercury, and iron. Heavy metal contents in the waters occasionally show local concentrations. The zinc content can be related to known minor mineralized areas around Springfield. Some iron content in the surface waters and shallow aquifers is contributed by the iron-bearing clays and pyrites in the shallow formations.

The ranges of heavy metal values in the Springfield area are in ppb: lead, 1 to 70; …

Approximate Normal Mode Method To Determine The Response Of Certain Nondiagonalizabel Vibratory Systems, Jayaram Seshadri

Masters Theses

"An approximate normal mode method is developed which permits certain normally nondiagonalizable, nonconservative systems to be solved by superposition of uncoupled coordinates.

An approximate solution for a nonproportionally damped, multi-degree of freedom system is obtained by using a perturbation technique. The system is then reduced to a proportionally damped system by means of a modification to the damping factor so that the effect of the off-diagonal terms of the modal damping matrix is included. This modification produces a damping matrix that can be diagonalized by the normal mode technique. An approximate criterion is used for the determination of the modified …

A New And Direct Process For The Reduction Of Lead Sulfide, Rolando Oscar Fernandez

Masters Theses

"The direct reduction of lead sulfide concentrates by iron was investigated. An oxygen-bearing flux was shown to be a necessary ingredient for complete reduction of the concentrate. The effects of time and temperature on lead recovery were studied. Only a trace amount of sulfur dioxide is evolved during reduction, which is in agreement with thermochemical calculations"--Abstract, page ii.

General Theory Of Diffusion-Controlled Reactions, Gerald Wilemski, Marshall Fixman

Physics Faculty Research & Creative Works

A formal mathematical description of diffusion-controlled bimolecular reactions is presented. The theory is completely general with respect to the kinds of reaction processes that may be considered. Besides the presentation of the general formalism, the paper also contains several examples illustrating the application of the theory to a simple many-particule system for simple catalytic bimolecular reactions, including fluorescence quenching. The manner in which approximate solutions may be obtained is also outlined.

Penetration In Granite By Jets From Shaped-Charge Liners Of Six Materials, Ronald R. Rollins, George Bromley Clark, H. N. Kalia

Mining Engineering Faculty Research & Creative Works

A new application of theory for three-dimensional collapse of conical liners shows why the two-dimensional analysis may offer a good approximation. Shaped-charge design parameters and rock target properties were investigated to determine their effects on penetration and breakage. Several metals, liner thicknesses, cone angles and standoff ranges for each were investigated. Effective standoff is greater for aluminum than more dense metals. Jets from the 60° monel, brass and steel liners gave the deepest penetration in granite. Jets from copper and brass liners gave equal penetration for 42° apex angles. Liners containing zinc produced small slugs or none at all. The …

Polynary Silicon Arsenic Chalcogenide Glasses With High Softening Temperatures, H. E. Anthonis, N. J. Kreidl, W. H. Ratzenboeck

Materials Science and Engineering Faculty Research & Creative Works

The introduction of Ag in SiAsTe glasses permits the incorporation of Se, otherwise volatile and/or degradable as a constituent in Si-containing chalcogenide glasses. SiAsAgTeSe glasses exhibit much higher softening ranges and glass transition temperatures than encountered in known chalgogenide systems. A glass Si35As15Ag10Te20Se20 had the viscosity log ν = 13 at about 500°C, as compared to 370°C for the base glass Si35As25Te40, the viscosity of log ν = 9.8 at about 560°C, as compared to 442°C for the base glass. Phase separation occurs in the system SiAsAgTeSe and becomes manifest in two glass transitions indicated by changes in the slopes …

Oxidation Of Tetragonal Pbo In Air, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Isothermal oxidation of tetragonal PbO in air produced multiphase assemblages with apparent equilibrium compositions which varied linearly with temperature from PbO1.548 at 286°C to PbO1.333 at 351°C. Oxidation at each temperature was relatively rapid to PbO1.40 and very slow from PbO1.40 to apparent equilibrium values. Pseudocubic PbO1+x, with compositions between PbO1.41 and PbO1.57, was indexed on a cubic unit cell at the lower O/Pb ratios and on a tetragonal unit cell at the higher ratios. Linear changes in lattice parameters and deviation from cubic symmetry accompanied reversible oxidation and reduction of the phase. Pseudocubic PbO1+x was reduced irreversibly to Pb3O4 …

Note On The Poisson Distribution, I. Adawi

Physics Faculty Research & Creative Works

No abstract provided.

Chemical Shift Parameters For Shallow Donors In Semiconductors, Edward Boyd Hale

Physics Faculty Research & Creative Works

A model for a shallow donor impurity in a semiconductor is used to calculate two relationships and several conditions involving the chemical shift parameters. The model is based on the standard effective mass form for the donor electron wave function, the existence of a potential in the chemical cell which may be real, pseudo, or rather general in nature, and a few somewhat restrictive approximations. The parameters, Δ, δ and Λ are theoretically calculated and are shown to be related if the approximations are valid. These parameters determine the 1S multiplet level structure and it is shown how properties of …

Total Electron Impact Ionization Cross Section In Rubidium From Threshold To 250 Ev, Kaare J. Nygaard, Yu Bong Hahn

Physics Faculty Research & Creative Works

A study of ionization in rubidium has been made in a crossed atom-electron beam apparatus. At an electron energy of about 10 eV there is a maximum in the cross section corresponding to the maximum probability for removal of the 5s valence electron. At 16.5 eV we have observed a new peak that is caused by the mechanism of autoionization. For energies below 30 eV there is a good agreement, both in shape and magnitude, between the present measurements and the empirical formula of Lotz. The over-all uncertainty in the measurements is ± 12% which is mostly accounted for by …

Production Of Metastable Ions In Cesium-Atom-Electron Collisions, Kaare J. Nygaard, Yu Bong Hahn

Physics Faculty Research & Creative Works

The structure in the total electron-impact ionization cross section in cesium can be partially accounted for by the mechanisms of autoionization and excitation ionization of 5p electrons. For electron energies above 17 eV a large fraction of the ions are metastable and can de detected by Auger emission from a metal surface. The experiment was performed in a cesium-atom-electron crossed-beam apparatus, and the metastable ions were counted with a channel electron multiplier. The metastable-ion count rate was a factor of 100 higher than that due to photons from atomic and ionic transitions. We have measured the over-all excitation function for …

Absolute Differential Elastic- And Inelastic-Scattering Cross Sections In 25-140 Kev He+ + He Collisions, Victor Pol, Walter Kauppila, John T. Park

Physics Faculty Research & Creative Works

Data obtained as energy-loss spectra at angles from 0 to 7.3x10-3 rad (c.m.) with typical energy-loss resolution of 0.7 eV and angular resolution of 2x10-3 rad (c.m.) were used to calculate average differential cross sections dσdΩav for elastic scattering, direct excitation of the individual He(n=2) states, and direct excitation of the He+(n=2) states. The total cross section for excitation of the He(n=2) states obtained by integrating the differential cross sections was found to be 20x10-18 cm2 at 25 keV (lab) decreasing to 7x10-18 cm2 at 140 keV. At incident lab energies below 100 keV the He(2S2) and He(2P3) states dominate …

Molecular Beam Measurements Of Total Collision Cross Sections Of H 22o, William R. Snow, J. T. Dowell, J. G. Chevrenak, H. E. Berek

Physics Faculty Research & Creative Works

The total cross section for H22O-H22O scattering is measured with a supersonic nozzle beam system. The primary beam has a narrow velocity distribution, and the velocity is varied by control of the nozzle temperature. Velocities are determined by time-of-flight techniques. Cross sections obtained are averages over a Maxwellian distribution of the target molecules. Data at three velocities are presented. The cross sections for H2O are surprisingly small, for example, 3.07 x10-14 cm2 at 1x105 cm/sec, indicating little contribution from the dipole-dipole interaction.

On The Effect Of Cesium In Photoionization Laser Plasmas, Kaare J. Nygaard

Physics Faculty Research & Creative Works

A number of photoionization mechanisms and how they can be used to generate large-volume laser plasmas are discussed. Reaction rates for two-step photoionization of the cesium atoms as well as formation of molecular ions (Cs2+) are estimated. The necessary cross-section data were obtained from related research in thermionic energy converters. © 1973, IEEE. All rights reserved.