Physical Sciences and Mathematics Commons^™

Electron-Impact Lonization Cross Section In Cesium, Kaare J. Nygaard

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The total ionization due to the passage of an electron beam in cesium vapor has been measured with a Tate and Smith-type apparatus. The retarding potential difference method was used in the electron gun to obtain energy resolution better than 0.1 eV. The density of Cs atoms was determined from the Taylor and Langmuir formula and also measured with a surface-ionization detector. The two methods gave the same density to within ±3% when the apparatus was in thermodynamic equilibrium with the Cs reservoir. The cross section for production of Cs+ has been determined from threshold to 100 eV. For energies …

The Bethe-Weizsäcker Mass Formula And Lennard-Jones N-N Potentials, James Paul Wesley, Alex E.S. Green

Physics Faculty Research & Creative Works

An elementary derivation of the Bethe-Weizscker semiempirical nuclear mass formula which is in the spirit of current views of nuclear structure, is given. Lennard-Jones potentials are assumed to act between nuclear. Thus, the major interaction between nn, pp, and np pairs is taken of the form —g/r3+h/r4, where r is the separation distance between nuclear, and g and h are constants. An additional "symmetry" interaction of the form s/r3 is assumed for np pairs. Summing the potential energy over all nucleon pairs and using the Fermi statistical estimate of the kinetic energy, the Bethe-Weizscker semiempirical mass formula is obtained directly. …

Current Density-Anodic Potential Curves Of Single Crystal Gaas At Low Currents In Koh, Martin E. Straumanis, J. P. Krumme, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

Single p-type, GaAs crystals of high purity, Zn doped, were used to determine whether or not the inverse octahedral {111} faces show potential differences and various rates of anodic dissolution. The Ga{111}, As{111}, {110}, and {100} faces, were polished, etched, and etch-polished with concentrated H₂SO₄ + H₂O₂, and immersed in IN KOH. The Ga{111} faces were found to be the most noble with respect to rest and anodic dissolution potentials. The potential difference between the inverse {111} faces was as large as 0.14v for the rest and 0.123v for the dissolution potentials. The …

Inferences On The Parameters Of The Weibull Distribution, Darrel Ray Thoman

Doctoral Dissertations

"For the most part, solutions to the problems of making inferences about the parameters in the Weibull distribution have been limited to providing simple estimators of the parameters. Little has been known about the properties of the estimators. In this paper the small and moderate sample size properties of the maximum likelihood estimators are studied and their superiority is established. The problem of making further inferences which are based on the maximum likelihood estimates of the parameters is then considered. The inferences that are presented can be divided into those based on a single sample and those based on two …

Geochemical Abundance Of Iodine, Jane Hanisch Bennett

Masters Theses

"The research reported herein includes unpublished iodine and uranium data on a group of United States Geological Survey standards and on a group of ultrabasic rocks. Data are also included for the major rock types, deep sea sediments, and for graphite and troilite inclusions in iron meteorites. Tellurium data for the troilite are also reported. Appendix I is a literature article (Bennett and Manuel, 1967a) on Canyon Diablo Graphite. Appendix II is a literature article (Bennett and Manuel, 1967b) on deep sea sediments. The results of this study show that most of the earlier estimates of the crustal abundance of …

Design And Testing Of A Downhole Continuous Wave Generator, Cole L. Smith

Masters Theses

"The continuous shear wave generator was designed to be the first instrument capable of producing a continuous high frequency signal below the weathered layer of the earth. This is to be accomplished by placing the instrument in a bore hole and lowering it below the weathered layer where the higher frequencies are severely attenuated. The generator produced a measurable signal output with the output force being approximately 11 pounds force. Testing of the generator showed the necessity of using a spring system with a low natural frequency. The testing also indicated several improvements which should be made in the generator …

Sulfide Mineralogy And Fabrics Of The Iron Ores At Benson Mines, New York, Pedro Hugo TumialáN De La Cruz

Masters Theses

"The occurrence of sulfide minerals and their textural relationships to the silicate and oxide minerals in the Benson Mines, New York, iron deposit were investigated by ore microscopic and petrographic means. The Benson deposit is one in which the dominant iron oxides, magnetite and hematite, occur in a quartz-feldspar gneiss which was subjected to hornblende granulite subfacies metamorphism. Two hundred ore and country rock specimens were systematically collected from all parts of the open pit mine. Polished sections and thin sections were prepared from nearly all of the collected specimens. The oxide ore exhibits a granular texture in which isolated …

Magnetic After-Effects In Dilute Transition Metal Alloys, Robert Henry Graham

Masters Theses

"Temperature dependent after-effects of the initial permeability in ternary dilute ferromagnetic iron-base alloys were studied in the temperature range of -50°C to +30°C. Interstitial carbon and nitrogen were the diffusing elements. Nominal percentages of the substitutional transition elements manganese, chromium, vanadium and titanium were added to determine the extent of substitutional-interstitial pair interactions. No additional temperature dependent after-effect of the initial permeability was noticed in Fe- substitutional -C alloys, while such after-effects were present in Fe- substitutional -N alloys. Magnetic after-effect data were analyzed on the basis of single Debye relaxations. Relaxation times for carbon and nitrogen diffusion in alpha-iron …

Endogenous Metabolism Of Polyporus Sulfureus. : Utilization Of Exogenous Carbohydrates And Fatty Acids, Shu-Mei Wang

Masters Theses

"A strain of Polyporus sulfureus from the collection at the University of Missouri at Rolla was used in this investigation. Organisms of this genus have been reported to produce eburicoic acid in good yield and this was confirmed for the organism used in this study by the isolation and identification of eburicoic acid from the mycelium. Growth studies of this organism showed that 4% malt extract is a better medium than synthetic media containing asparagine, nitrate or nitrate plus 0.5% yeast extract as nitrogen sources. An examination of the pH of the culture medium led to the conclusion that regardless …

A Study Of Succinic Dehydrogenase, Indole Acetic Acid Oxidase, Nitrate Reductase And Cytochrome C Reductase In Hygrophorus Conicus, Jagdish M. Mehta

Doctoral Dissertations

"The activity of the enzyme succinic dehydrogenase (succinate : phenazine methosulfate oxidoreductase, EC 1.3.99.1) of Hygrophorus conicus, a member of a class of fungi known as basidiomycetes, was found to be stimulated by nitrate. Two substances were tested as electron acceptors in the measurement of succinic dehydrogenase activity. Of the two substances tried, phenazine methosulfate and brilliant cresyl blue, the former was found to be the best. Nicotinamide adenine dinucleotide (NAD⁺) was a necessary cofactor for the enzyme and could be readily dissociated from the enzyme. The enzyme has the properties of a high molecular weight nucleo- or lipoprotein.

The …

Mineralization Of The Boss Bixby Anomaly, Iron And Dent Counties, Missouri, Frederick Joseph Smith

Masters Theses

"The Boss-Bixby deposit is located on the line dividing Iron and Dent Counties and belongs to the Southeast Missouri Precambrian Iron Metallogenic Province. The sequence of events leading to the formation of the deposit is reviewed. The mineralization occurred after intrusion of intermediate magma, but prior to the intrusion of granite. The ore minerals present are the following in the order of deposition: magnetite, ilmenite, giekielite, hematite, rutile, pyrite, molybdenite, cobaltite, chalcopyrite, bornite, sphalerite, galena, limonite, chalcocite, and cuprite. Four different methods of zoning are presented. Partial pressures of oxygen and sulphur [sic], as well as temperature controlled sequential deposition …

A Study Of Solvent Effects On The Reaction Between P-Nitrobenzyl Chloride And Hydroxide Ion In Aqueous Dioxane Homogeneous Media, Ken K. Ho

Masters Theses

"The kinetics and activation parameters of the reaction between p̲, p̲' - dinitrostilbene quantitatively, have been studied in five aqueous dioxane solvent systems at five different temperatures between 20⁰ and 40⁰C. At any one temperature the second-order rate constants are minimum in the 30% dioxane solvent mixture, reach a maximum in the 50% dioxane systems, and fall off slightly in the 60% and 70% dioxane systems. The Arrhenius activation energies are highest in the 30% dioxane and lowest in the 70% dioxane systems. The free energies of activation change in the same direction but the magnitude of change is much …

Electronic Transitions In Diatomic Molecules, James O. Hornkohl

Masters Theses

"The electronic transition moments of many band systems have been found to be linear functions of the internuclear distance. However, some band systems exhibit a quadratic variation of the transition moment. In these quadratic cases, the plots from which the variation of the transition moment is determined are based upon the approximation of the second r-centroid by the square of the first r-centroid. The square of the first r-centroid does closely approximate the second r-centroid by a simple error analysis shows that the small difference between the two is not a quantitative measure of the error introduced into the transition …

Infrared Related Solid State Studies, Donald George Rathbun

Masters Theses

"Infrared reflectivity measurements have been made on single crystal CdS. Classical dispersion analysis has been used in an analysis of the data to obtain the index of refraction, the extinction index, and the dispersion parameters. These are compared with previously published results. The procedure used in this analysis has been outlined for future reference. Also, the shallow donor impurity theory has been used to numerically calculate the d_±1 levels for Si and Ge. The theory is extended for the case of the impurity in the bulk semiconductor and the d₀, d_±2 and, for high n, the s, p₀, …

The Geology Of The Thayer Area Emphasizing The Stratigraphy Of The Cotter And The Jefferson City Formations, William Jesse Hedden

Masters Theses

"Detailed geologic mapping of the Cotter-Jefferson City formational contact in the Thayer, Missouri area demonstrates the feasibility of using this contact. This mapping also delineates significant faulting in the area.

The stratigraphy of the Cotter and Jefferson City formations in the Thayer area has been studied to find a mappable contact between the two formations. The contact was mapped in this area by using marker beds, the stratigraphic positions of which were determined by applying insoluble residue techniques to outcrop sections. Because the insoluble residue zones of the Cotter and Jefferson City formations are recognizable throughout the state of Missouri …

Strong-Coupled Piezoelectric Polaron, Wayne E. Tefft

Physics Faculty Research & Creative Works

A semiclassical, variational calculation for the strong-coupled piezoelectric polaron gives the following results for the ground-state energy and polaron radius, respectively: U0=-0.47(m*/m) (κ²/ε)²eV, and R=3.5(ε/κ²) (m/m*)â ã where m* is the band effective mass, κ is the electromechanical coupling constant, and ε is the strain-free dielectric constant. The theory is expected to be valid when |U0| is larger than thermal energies and R is considerably larger than unit-cell dimensions. A calculation of the polaron effective mass, having a more limited region of validity, gives mp~m*[1+2|U0|/m*vs²], where vs is the velocity of sound. …

Survival Probability In Dissociative Attachment, Joseph C.Y. Chen, Jerry Peacher

Physics Faculty Research & Creative Works

The survival probability in dissociative attachment is investigated with special attention to the (e, H₂ ) system. It is shown that the simple expression for the dissociative-attachment cross section, as given by the product of a capture cross section and a survival probability, is equivalent to the s -wave approximation for the g → g dissociative attachment. This expression, however, does not constitute an approximation for the g → u dissociative attachment, since the parity of the initial rotational states of H₂ is always opposite to that of the relative angular momentum states of H and H- …

Rapid Calculation Of Electron Scattering Factors, Jerry Peacher, John G. Wills

Physics Faculty Research & Creative Works

The phase amplitude method is used to reduce the radial Schrödinger equation to two separate differential equations, one for the phase and one for the amplitude. These functions are both smooth as opposed to the rapidly oscillating solution of the radial Schrödinger equation for electron energies in the kilovolt range. The partial-wave phase shifts were obtained rapidly by integrating the differential equations for the phase and amplitude numerically. Hartree-Fock and Thomas-Fermi-Dirac fields were used in the calculation. Results for argon and uranium are given in order to compare with previous results. It was found that the WKBJ approximation to the …

Tolerance Regions For A Joint Exponential Distribution, Lee J. Bain

Mathematics and Statistics Faculty Research & Creative Works

The evaluation of the reliability of a system of components, when the components are assumed to follow a joint exponential distribution, is considered. The approach used is to develop tolerance regions for the joint exponential distribution or to estimate the probability content of the appropriate specification region. Copyright © 1968 by The Institute of Electrical and Electronics Engineers, Inc.

A Study Of The Afterglow Of An R-F Excited Mercury Discharge, James A. Aubrecht

Masters Theses

"The short duration afterglow of an r-f discharge in mercury has been examined versus ground state mercury atom density and r-f power. The intensity of the 5771, 5462, 4360, 4079, 4047, 3907, 3651/56, 3342, and 3127/32Å atomic mercury lines were observed to decay as a function of time after the shut off of the active discharge. At temperatures below 333⁰K, all atomic lines decayed exponentially, and no molecular emission was observed. From 333⁰K to 423⁰K, the atomic lines were observed to decay rapidly initially, then exhibit an enhancement effect in intensity which was produced by metastable atom collisions, and finally, …

A Study Of An Electric Method To Excite And Detect Acoustic Waves In Solids, John H. Stevens

Masters Theses

"This experiment has demonstrated that it is possible to generate pulses of acoustic waves in an aluminum single crystal by the direct use of the tensile stress associated with an electric field at the surface of a conductor, and it is possible to detect these waves with a biased, capacitive pickup transducer"--Abstract, page ii.

Comparative Analysis Of Polynomial Root Finding Techniques, Charles Ray O'Daniel

Masters Theses

"The purpose of this study was to investigate and recommend various methods instrumental in finding the roots of a polynomial p(x) = 0. Many different methods are present today, and each has its advantages and disadvantages.

Through thorough investigation, the author has ascertained the key methods to be the method of Bisection, the Newton-Raphson method, and the Bairstow method. Special support in the form of algebraic theorems on the locations and kind of roots are extremely helpful. This combination of theorems and methods provides assurance, speed, and the ability to obtain complex roots.

The Bisnewbar method developed by this author …

Infrared Spectra And Magnetic Properties Of Fluorine Substituted Copper (Ii) Alkanoates, Jose G. Rodriguez

Masters Theses

"The purpose of this study was to prepare some selected copper(II) fluorcalkanoates, investigate their magnetic susceptibilities, study the infrared spectra of these salts and compare these properties to those of the unfluorinated copper(II) alkanoates….

The experimental data obtained indicate that the copper(II) trifluoroacetate, perfluoropropanoate and perfluorosuccinate does not form a binuclear cage structure. Copper(II) 3-(trifluoromethyl) butanoate with a magnetic moment of 1.4 should possess a binuclear case structure similar to copper( II) acetate monohydrate. The structure for copper( II) perfluoroglutarate monohydrate with a magnetic moment of 1.63 B.M. should have a structure somewhere between the two aforementioned structures"--Abstract, page ii.

Effect Of Environmental Hydrogen Pressure On The Hydrogen Yield From X‐Irradiated Polyethylenes, Otto H. Hill, R. Pat Lightfoot

Physics Faculty Research & Creative Works

An experimental assembly incorporating a capacitance‐type, differential pressure transducer, which provides resolutions of 3 x 10−4 torr at pressures extending to 30 torr, has been employed to monitor the effect of hydrogen environmental pressure on the hydrogen yield from x‐irradiated polyethylene's. Contrary to the observations of previous investigators, the hydrogen yield is found to be independent of hydrogen environmental pressures extending over the critical range up to at least 30 torr. It is demonstrated that neglecting the temperature and density gradients inherent in closed‐volume irradiation assemblies employing cryogenic traps to separate liberated gases into condensable and non condensable fractions may …

Ferroelectric Properties Of Pbzro₃-Bifeo₃ Solid Solutions, Robert Gerson, Pen-Chu Chou, William Joseph James

Physics Faculty Research & Creative Works

Solid solutions of BiFeO and PbZrO₃ were investigated for crystallographic and dielectric properties. A new pseudocubic perovskite phase was found, which has been tentatively indexed as orthorhombic with the same unit cell as PbZrO₃ but with dielectric properties characteristic of a ferroelectric substance. The Curie point in this series of solid solutions has a minimum of about 155°C at a composition of about (PbZrO₃)_0.80 (BiFeO₃)_0.20, which at room temperature lies on the boundary between the orthorhombic antiferroelectric and the pseudocubic ferroelectric phases. This composition has a relative dielectric constant of 800 …

The Mechanism Of The Electrooxidation Of Acetylene On Gold, James W. Johnson, J. L. Reed, William Joseph James

Chemical and Biochemical Engineering Faculty Research & Creative Works

Acetylene has been oxidized anodically in aqueous solutions at 80 °C on gold electrodes. It was found that the partial oxidation to CO₂ was accompanied by a polymer formation. Effects of potential, acetylene partial pressure, pH, and temperature on the rate (current) were measured. A discontinuity in the Tafel curves was noted that indicated a change in the reaction mechanism with potential. The discontinuity was also pH dependent. A mechanism involving the discharge of H₂O and/or OH− has been proposed that is consistent with the experimental results. © 1967, The Electrochemical Society, Inc. All rights reserved.

Radial Pressure Gradient In Turbulent Pipe Flow, Gary Kent Patterson, Walter J. Ewbank, Virgil A. Sandborn

Chemical and Biochemical Engineering Faculty Research & Creative Works

Measurements made with a Prandtl static pressure probe have demonstrated that a radial pressure gradient does exist in turbulent pipe flow with approximately the magnitude predicted by Sandborn from hot-wire anemometry measurements.

The Effect Of Concentration On The Viscosities Of Solutions Of Linear Flexible High Polymers, Lung Yu Chou, Jacques L. Zakin

Chemical and Biochemical Engineering Faculty Research & Creative Works

Viscosity-concentration results in the moderately concentrated range for four samples of polyisobutylene (molecular weights of 1.3 x 104 to 1.0 x 106) in cyclohexane (concentrations up to 4.7 g./dl.) and in benzene (concentrations up to 7.0 g./dl.) at 24°C. (a theta solvent) showed molecular weight and goodness of solvent dependencies similar to those reported earlier for three other polymers. For polyisobutylene, polystyrene, and a copolymer of styrene and methyl methaerylate in good solvents, viscosity-concentration data plotted as ηsp. C[η] vs. k′[η]C fit a single curve. The linear region of this curve suggests that the Huggins equation is useful to C[η] …

Kilocycle Range Dislocation Damping In Dilute Magnesium Alloy Single Crystals, Robert Ray Nothdurft

Doctoral Dissertations

"The kilocycle range dislocation damping and Young's modulus of single crystals of magnesium and single crystals of magnesium containing small additions of lithium, zinc, or aluminum have been studied as a function of strain amplitude, temperature, and time during annealing and following a high strain amplitude vibration. The data are compared to the Granato-Lücke theory of dislocation damping, the Granato-Hikata-Lücke theory for the recovery of damping following plastic deformation, and the Yamafuji-Bauer theory for the recovery of damping following a high strain amplitude vibration. Reasonable qualitative agreement is obtained between the Granato-Lücke theory and the observed dependence of the damping …

The Role Of The Doctor Of Engineering Degree In Graduate Education, Wouter Bosch, Robert E. Carlile

Chemistry Faculty Research & Creative Works

No abstract provided.