Digital Commons Network^™

The Interfacial Phenomena Of Liquid Copper Of Sapphire Substrates, Jenq Liu

Masters Theses

"The wetting behavior of liquid copper on the sapphire is effected by the crystallographic orientation of the solid surface, the oxygen partial pressure, and the temperature. Each of these influences has been studied by the sessile drop technique, over the oxygen partial pressure range from 10^-2 to 10^-20 atm at temperatures of 1373°K, and 1523°K. The effect of oxygen partial pressure on the liquid copper surface energy follows the Gibbs Langmuir Law.

The crystallographic orientation of the sapphire surface causes variations in the contact angle. This is more significant for higher oxygen partial pressure, but is eliminated at …

The Effect Of Excess Lead Oxide On The Sintering Characteristics And Dielectric Properties Of Lead Magnesium Niobate Ceramics, Dyllan Jye-Lun Hong

Masters Theses

"The effect of lead oxide additions on sintering characteristics and dielectric properties of ferroelectric Pb₃MgNb₂O₉ based capacitors was studied. The basic dielectric compositions were formed by solid state reaction. Densification was studied as a function of PbO content over the temperature range 900 °C to 1000 °C for sintering times one to six hours depending on the amount of additive, and the sintering temperature.

Weight loss, density and shrinkage measurements of each composition were made in order to relate the effects of the excess PbO additions on the densification. The dielectric and electrical properties were …

Sensitivity Of The Ellipsometric Parameters To The Angle Of Incidence For Gaas, Jie-Fang Li

Masters Theses

"Ellipsometry was used to study a 10¹⁸ si-doped GaAs substrate and a 5 μm metal organic chemical vapor deposited (MOCVD) GaAs film on a similar substrate. The sensitivity of Ψ and Δ to Ø was studied, and the region of highest sensitivity was found for both samples. The optical constants for the 10¹⁸ Si-doped GaAs substrate and the 5 μm GaAs film were found to be N₂ = (3.768-0.491j) and N₂ = (3.704-0􀁐599j), respectively. The dependence of the sensitivity of Ψ and Δ to Ø was also calculated for various optical constants"-- Abstract. p. ii

Formability Of 356 Aluminum, Karol Krumrey Schrems

Masters Theses

"Although aluminum casting alloys are not often thought of as being formable, this thesis examines this possibility. Aluminum alloy 356 was cast in permanent molds and subsequently deformed by rolling (providing compressive loading) and bending (providing tensile loading). Cold forming was found to be very limited, while forming at elevated temperatures was comparatively easy and permitted reductions of up to 90%. Tensile properties and microstructures were examined in detail. Forming breaks up the eutectic silicon and intermetallic compounds. The yield strength and tensile strength increased almost linearly with increasing total percent reduction. The elongation at first increases with total percent …

Design Of A Meta-Assembler For Microprogramming And A Survey Of Microprogram Optimization Techniques, Rahul Saxena

Masters Theses

"The purpose of this thesis is to develop and implement a meta-assembler for microprogramming. Different methods for optimizing microprogram execution and storage are also investigated.

The meta-assembler is of an adaptive type. It allows complete flexibility in the definition of the target machine op-codes and microinstruction field formats. The assembly process consists of two main phases. In the first phase the assembler builds a description of the target machine in terms of its microinstruction field format definitions. In the second phase the source program is assembled into object microcode. The assembler is written in the language Pascal. The assembler is …

Design Of Multivariable Deadbeat Controllers Using Reduced Order Models, Joaquin Alberto Zuniga

Masters Theses

"This study is concerned with the design of minimum Frobenius norm deadbeat controllers using reduced order models. Deadbeat controllers force the non-zero initial states of a linear multivariable discrete time system to the origin of the state space in minimum time. A controller of minimum Frobenius norm achieves such response with least effort.

The deadbeat controllers are designed on the basis of eigenspectrum assignment. In general, this approach permits a freedom in the selection of the closed-loop Jordan matrix which is used in the design of parametric controllers.

In this presentation, it is demonstrated that the task of deadbeat controller …

Mechanical And Neutronic Properties Of Neutron Absorbing Materials, Donald James Buth

Masters Theses

“The primary neutron absorbing material examined in this project was Boraflex™, which consists of a silicone polymer with boron carbide acting as the neutron absorber. Two aluminum based neutron absorbers, Boral™ and Al-B-Ten, were also examined. Both X-ray and neutron radiography were used to examine the Boraflex™. The neutron radiography gave better resolution in detecting fluctuations in the boron carbide distribution; however, X-ray radiography did perform better in detecting flaws in the base material. Tensile tests were performed to determine the uniformity of Boraflex™'s tensile properties. The average tensile strength was calculated to be 303 ± 15 psi. A small …

Effects Of The Luminous Environment On Managerial Decision Making, Marc Clay Belcher

Doctoral Dissertations

"Little is known about the influence the physical environment may have on the way a manager goes about making decisions. This work considers one element of the environment, lighting, and attempts to establish a relationship between that element and the decision strategy a manager may select.

From a review of the literature on the effects of light on man and from the field of decision making, a model is posited suggesting that the luminous environment affects decision making. Since others have established that mood influences how decisions are made, and since it is suggested in the literature that lighting affects …

Lithofacies Analysis Of The Lamotte Sandstone In South Central Missouri, Michael Gerard Kraenzle

Masters Theses

"Based on the analysis of thirty-one cores obtained from the Missouri Department of Natural Resources in Rolla, the upper Cambrian Lamotte Sandstone in South Central Missouri has been divided into six sedimentary facies ranging from alluvial fan and braided stream to open marine.

The Lamotte Sandstone is the basal Cambrian sandstone found throughout most of the state of Missouri. It directly overlies late Precambrian (1.4 to 1.5 billion year old) granites and metasediments. The Lamotte and overlying Bonneterre Formations are generally considered to have been deposited by a transgression which occurred during the Late Cambrian Period (Croixian Epoch).

The Lamotte …

Characterization Of The Fluid-Dynamic Mixing Of A Bottom Gas-Injected Channel Reactor Using Low-Temperature Modelling, Jay Bernett Gassel

Masters Theses

"Variables influencing the mixing in a single-phase (30.5 x 60 x 606 cm) and a two-phase (20 x 40 x 200 cm) channel reactor model were studied. Tracer and/or neutral density particle techniques were used to determine an eddy diffusivity, De, for the system(s). Three bubbler arrangements were investigated in the one-phase work. A separate apparatus was developed to withstand the corrosiveness of the tetrachloroethylene used in the two-phase work.

Both the electrical conductivity tracer technique and the neutral density particle technique were shown to be feasible experimental techniques for determining an eddy diffusivity in the systems studied. Decreasing liquid …

A Proposed C Language Binding For The Graphical Kernel System-3d, Mark Gerard Bolten

Masters Theses

"This thesis introduces a proposed C language binding definition for the International Standards Organization's draft international standard of the Graphical Kernel System-3D. This work augments the earlier C language binding of the two dimensional version of the Graphical Kernel System commonly known as GKS. The proposed function interface will provide a basis for, if not a final, C language binding for the three dimensional version of the Graphical Kernel System"--Abstract, page ii.

Implementing An Mrp System In A Job Shop Environment, Kathleen A. Behnke

Masters Theses

"In today’s highly competitive marketplace, many small manufacturers are struggling to survive. The competition to produce a quality product at a competitive price comes not only from other small companies, but also from larger companies and foreign manufacturers, who have learned to produce in a more economical fashion. The challenge of the small manufacturer is learning to compete.

Every manufacturer, whether large or small, has one basic objective: to be profitable. The profit objective is usually achieved using a three part strategy of maximizing customer service, minimizing inventory investment, and maintaining efficient plant operation.

Small companies, including the one in …

Fundamental Study Of The Role Of Cathode Structure On Zinc Electrowinning, Horacio M. Aros

Doctoral Dissertations

"The influence of cathode macromorphology on the current efficiency of zinc electrowinning was determined.

The studies have shown that surface roughness affects current efficiency during zinc electrowinning, particularly when the electrolyte contains impurities such as nickel and antimony. Current efficiency does not change with surface roughness as long as the electrolyte is sufficiently pure.

Zinc deposited on smooth zinc cathodes tends to retain a more favorable structure and macromorphology, which is less sensitive to the effects caused by antimony and nickel. Glue helps to counteract the effect of the impurities; however, its presence in the electrolyte at certain combinations with …

Experimental Vapor-Liquid Equilibria Of Propyne With Propane, Propene And Propadiene, Edward Allen Kyser

Doctoral Dissertations

"Vapor pressures for pure propane, pure propene, impure propadiene and pure propyne and 19 binary mixtures of propane, propene, and propadiene with propyne are reported at -20, 5, 30, 55 and 80° C. An equation of state utilizing pure component saturated vapor and liquid densities is used to correlate all the data and the effect of the propadiene impurities was theoretically removed. The data of Burcham (1981) are recorrelated using new information about the impurities, and different results are obtained. Calculated relative volatilities and saturated densities are reported for the systems propane-propyne, propene-propyne, propadiene-propyne and propane-propadiene"-- Abstract, p. ii

Microemulsions, Lyotropic Liquid Crystals, And Other Association Structures, Jiafu Fang

Doctoral Dissertations

"Phase diagrams have been determined showing the extent of the inverse micellar or microemulsion region for several ionic surfactants and some cosurfactants. Hexylamine has been found to be a very effective cosurfactant giving rise to very good water solubilizing capacity at extremely low surfactant concentrations and very low cosurfactant levels at rather high initial hydrocarbon levels.

A fairly extensive study of phase equilibria of the system composed of sodium dodecyl sulfate, hexylamine, heptane, and water has been carried out. The conductivity behavior of the inverse micellar or microemulsion phase of the system shows the percolation phenomenon. Low angle X-ray diffraction …

Phase Equilibria From Pvt Measurements For Carbon Dioxide, Water And N-Decane, Michael Nduka Okafor

Doctoral Dissertations

"Phase equilibrium properties for the carbon dioxide - water - n-decane system were determined from pressure-temperature-volume (PVT) measurements. PVT properties were also obtained for pure carbon dioxide and water, and the binary mixtures of carbon dioxide - water and carbon dioxide - n-decane. The experiments were conducted at temperatures of 313.17, 353.15 and 393.15 Kelvin, and at pressures from 37 to 416 bar. Measurements for the mixtures were terminated when complete miscibility was observed.

The Perturbed-Hard-Chain (PHC) equation of state developed by Gmehling et al. (1979) was chosen to correlate the measured data because of its ability to handle the …

Amphiphile Association Structures, Yun Yang

Doctoral Dissertations

"The amphiphile association behavior of Aerosol OT (sodium di-w-ethylhexylsulfoccinate) and p-xylene in combination with mixtures of different ratios of glycerol/water systems was studied and compared to that in the corresponding water and glycerol systems. The presence of glycerol strongly destabilized the inverse hexagonal liquid crystal phase observed in the aqueous system. The glycerol showed more ability to penetrate into the amphiphile bilayer than water in the lamellar liquid crystal phase. The influences of water and glycerol on the organization of amphiphile in the lamellar liquid crystal phase are of the same order.

The gross diffusion coefficient of 1% 2,4-diamino-6-piperidinopyrimidine-3-oxide in …

Studies Of Defect Structure And Oxidation-Reduction Behavior Of Undoped Lamno₃, Sr-Doped Lamno₃ And Mg-Doped Lamno₃, Jen-Ho Kuo

Doctoral Dissertations

"Undoped LaMnO₃, Sr-doped LaMnO₃ and Mg-doped LaMnO₃ showed reversible oxidation-reduction behavior. These perovskites can be excess, stoichiometric or deficient in oxygen content depending on the specific conditions. Under very reducing conditions these oxides will decompose into new phases. Phase stabilities for these oxides were determined. The results showed that both Sr and Mg doping caused the LaMnO₃ to dissociate at higher oxygen activities than for undoped LaMnO₃.

Defect models were proposed to interpret the TG results, in which metal vacancies are assumed for the oxygen excess condition and oxygen vacancies are assumed for the oxygen deficient condition. Thermodynamic properties were …

Bubble Formation, Movement And Distortion In Viscous Glass, Simon Cheng-Ping Wang

Doctoral Dissertations

"A study of bubble formation, movement and distortion in viscous glass is described. A glass rod containing an irregularly shaped hole is heated to a temperature at where the glass viscosity is low enough to let the hole form a spherical bubble. Spheration occurs as the bubble moves upward in the glass rod. At the proper time, the rising bubble is decelerated and brought to a stop by increasing the glass viscosity by slowly reducing the temperature. The entrapped bubble is then cut from the glass rod and heated again, if necessary, to a lower temperature, to reduce distortion of …

The Missouri Miner, December 03, 1986

The Missouri Miner Newspaper

No abstract provided.

The Mg-Sb System, A. A. Nayeb-Hashemi, J. Beverley Clark

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Calculation Of Electron Capture Cross Sections Of Collisions Of Be ²⁺ On H, A. E. Wetmore, H. R. Cole, Ronald E. Olson

Physics Faculty Research & Creative Works

Using the perturbed stationary state method, including electron translation factors, the authors have calculated electron capture cross sections for the helium-like ions Be²⁺ and B³⁺ incident on ground-state atomic hydrogen. The molecular structure calculation employs pseudo-potentials to represent the inactive K-shell electrons on the incident ions. The calculated cross sections vary rapidly in the 107 cm s-1 velocity range (E approximately 1 keV amu-1). The calculations show preferential transfer to the Be⁺(2s) and the B²⁺(2p) product states. The calculations for B³⁺+H are in good agreement with experimental measurements of Cradall et al …

Missouri S&T Magazine, December 1986, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Discussion Of "Lime-Enhanced Reduction Of Sulfide Concentrates: A Thermodynamic Discussion", Arthur E. Morris, Harry Flynn

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Double Electron Transitions In Collisions Between Multiply Charged Ions And Helium Atoms, Ronald E. Olson, A. E. Wetmore, M. L. Mckenzie

Physics Faculty Research & Creative Works

A semiclassical model for He is applied to the study of multiply charged ions colliding with He at intermediate energies. Single and double-electron capture and ionisation and capture-ionisation reactions are studied for incident-ion charge states q=+1 to +50 at 1 MeV amu-1. For charge states q>or approximately=+10, single electron capture is found to be dominated by a two-electron transition in which one electron is captured and the other is ionised.

Negative Ion Drift Velocities In Mixtures Of Methane And Sulphur Hexafluoride, M. C. Cornell, Ian M. Littlewood

Physics Faculty Research & Creative Works

The velocities of negative ions drifting in mixtures of methane and Sulphur hexafluoride have been measured. Measurements were made as a function of gas composition, reduced electric field strength between 3 and 185 Td, and total gas pressure in the range 100-600 Torr at 300K. The data indicate that SF 6- (SF6) ions are the dominant ion in all of the gas mixtures studied. Extrapolation of the data using Blanc's Law was used to determine the velocity of Sulphur hexafluoride ions drifting in pure methane.

Photoconductivity Parameters In Lithium Niobate, Robert Gerson, J. F. Kirchhoff, L. E. Halliburton, D. A. Bryan

Physics Faculty Research & Creative Works

Measurements on a variety of doped (magnesium and/or iron) and undoped lithium niobate crystals in the oxidized state demonstrate an Arrhenius dependence of dark conductivity on reciprocal temperature between 460 and 590 K. All of the crystals had roughly the same conductivity and activation energy (1.21 eV) over the temperature range, implying that all have about the same free-carrier concentration and mobility. The enhanced photoconductivity of magnesium-doped lithium niobate is attributed to a greatly reduced trapping cross section of Fe³⁺ for electrons, the smaller cross section being due to a changed substitutional site for Fe³⁺. The Fe …

The Missouri Miner, November 19, 1986

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, November 12, 1986

The Missouri Miner Newspaper

No abstract provided.

The New European Recommendations For The Design Of Light Gauge Steel Members, Per O. Thomasson

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

No abstract provided.