Digital Commons Network^™

Quenching Defects In Aluminum Plus Ten Atomic Per Cent Zinc, James Thomas Grider

Masters Theses

"This study was undertaken to resolve the conflict which has recently arisen as to the as-quenched microstructure in the Al-Zn system as revealed by thin film transmission electron microscopy. The composition range of most active study has been that from 5 to 15 atomic per cent Zn in superpurity AL. Consequently a composition of 10 atomic per cent Zn was chosen for this study. There are no discontinuties in the phase diagram in this composition range which would influence the above choice. It exists as a single phase solid solution at high temperatures and as a two phase alloy at …

The Design Of A High Temperature Thermoelectric Generator Element Using Silicon Carbide, John Talmage Barrow Jr.

Masters Theses

"This report presents the design of an optimum, high temperature silicon carbide thermoelectric generator element. The analytical efforts have been divided into three basic parts, the development of the theory, the accumulation of the data, and the optimization of the design. The first step in the theory development was the derivation of accurate design equations. With this done, the design philosophy and computer program were constructed, the latter utilizing a subroutine to contain the design equations. The data was obtained from a survey of many references and, for the most part, was found to be inexact, requiring the consideration of …

Low-Energy Electron Transport By The Method Of Discrete Ordinates, David E. Bartine

Doctoral Dissertations

"The one-dimensional discrete ordinates code ANISN has been adapted to simulate the transport of low-energy (on the order of a few MeV) electrons. Two different calculational techniques have been utilized for the treatment of electron-electron collisions that result in a small energy transfer. One method treats such collisions by a continuous slowing-down approximation, while the other method treats these collisions by the use of a very approximate cross section. Calculated results obtained with ANISN are compared with experimental data for the transmitted energy and angular distributions for 1-, 2.5-, 4-, and 8- MeV electrons normally incident on aluminum slabs of …

Theory Of Nucleation Of Water Properties Of Some Clathrate Like Cluster Structures, Mehdi Daee

Doctoral Dissertations

"The tranquility of classical homogeneous nucleation theory has been disturbed by the introduction of statistical mechanical correction factors to a basically thermodynamic theory. These factors, which appear to be essential, destroy much of the agreement with experiment in the case of water vapor. A molecular model for the pre-nucleation water clusters is proposed with a view toward resolving some of these difficulties. As a first step, the Properties of a few specific cluster configurations have been examined. Clathrate-like structures containing 16 to 57 water molecules are discussed. The hydrogen bonds were treated as simple harmonic oscillators for the purpose of …

Homogeneous Nucleation Of Water Vapor In Inert Gas Atmospheres, Arthur Henry Biermann

Doctoral Dissertations

"The homogeneous nucleation of water vapor in atmospheres of helium, neon, argon, krypton, and xenon was studied using an expansion type cloud chamber. A strong dependence of the nucleation rate on the particular inert carrier gas was observed. At present the only dependence upon the nature of the carrier gas included in classical nucleation theories is a small factor arising from kinetic considerations which is in the wrong direction to explain the observations. To explain the dependence of the rate on the nature of the carrier gas, a molecular cluster model is assumed allowing inert gas atoms to occupy the …

Synthesis, X-Ray Characterization, Structural And Magnetic Studies Of A New Class Of Iso-Structural Bimo₃ Compounds, Joseph Donato Bucci

Doctoral Dissertations

"This dissertation consists of four sections. The first part is a temperature dependent X-ray study of the lattice parameters of BiFeo₃. The synthesis and subsequent X-ray characterization of BiCo₃, BiAlO₃, BiMnO₃ , BiScO₃, BiCo₁₋ₓFeₓO₃ , and BiAl₁₋ₓFeₓO₃ are reported in the second part. These compounds all crystallize in the body centered cubic (BCC) structure with a~10.2Å. Single crystal Precession and Weissenberg photographs confirmed the BCC structure. In part three, the results of the magnetic studies on BiCoO₃ and biAl.₉FE.₁ are presented. The magnetic data for BiCoO₃ are substantiated by X-ray thermal expansion studies. In the last part the compound BiCo.₉FE.₁O₃ …

Photoionization Of Photoexcited Cesium, Robert E. Hebner

Doctoral Dissertations

"A new method for obtaining the cross section for photoionization of photoexcited cesium is presented. The salient feature of this experiment is to use three crossed beams, i.e., two light beams intersecting a beam of cesium atoms. The cross section is determined by counting the ions produced by the two step process: Cs (6S) + h[upsilon]₁ --> Cs (6P) ; Cs (6P) + [upsilon]₂ --> Cs⁺ + e⁻ The relative cross section for the second step has been obtained from threshold (5060 Å) to 2500 Å. The excitation light source used in obtaining this cross section was a rf resonance …

Alkali Mobility And Mechanical Relaxation In Mixed-Alkali Silicate Glasses, James W. Fleming Jr.

Masters Theses

"Internal friction and sodium and potassium self-diffusion coefficients for (1-X)Na₂O · XK₂O· 3SiO₂ glasses were measured. Alkali diffusion was measured between 300 and 500ºC using radioactive isotopes and a thin-sectioning technique. Internal friction was measured from room temperature to 500ºC, 0.1 to 2000 Hz. Comparison between alkali diffusion and internal friction data for Na-K glasses with those for other mixed-alkali glasses shows that the mixed-alkali peak is related to alkali mobility. It is concluded that the mechanism for mixed-alkali internal friction is a cooperative rearrangement of dissimilar alkali ions, with the slower moving ion controlling the rate of reorientation"--Abstract, page …

The Effect Of Solvents On The Desorption Of Phenol From Carbon In A Water Free System, William W. Knickmeyer

Masters Theses

"The desorption of phenol from active carbon was studied using a continuous flow desorber. The system used was nearly water free to reduce water-phenol interactions. The ten solvents used in this study exhibited a wide difference in their desorption capabilities. An attempt to correlate the desorption data with the physical properties of phenol and solvents, in addition to regular solution theory, proved unsuccessful. A thermodynamic approach using the linear free energy-enthalpy relationship produced a general trend by using the heat of solution for phenol in solution and a reasonable correlation using the heat of formation of the phenol-solvent hydrogen bond …

Anodic Oxidation Of Ethylenediaminetetraacetic Acid On Pt In Acid Sulfate Solutions, Howard Ho-Wei Jiang

Masters Theses

"The anodic oxidation of EDTA was studied in acid sulfate solutions on platinized-Pt at 25ºC. Polarization relationships were obtained for the EDTA concentration range 3. 42 x 10⁻⁵ to 3. 42 x 10⁻³ M and pH range 0. 35 to 3. 80. Numerous reaction products were identified that indicated a sequential removal of acetate groups from the EDTA, each by an initial decarboxylation followed by a reverse Schiff-type reaction, that produced formaldehyde and the corresponding amine. A reaction sequence which correlated the experimental data involved Frumkin-type adsorption of the EDTA species through an unionized acetate group followed by a rate-determining …

Electrolytic Reduction Of Zinc From Acidic Sulfate Solutions, Kenneth Dale Gielow

Masters Theses

"Cathode polarization curves were obtained for the electrodeposition of zinc from sulfate solutions with pH 2 and zinc concentrations of 10.0, 40.0, 80.0, and 100.0 gpl zinc. Both pure zinc and pure aluminum were used as cathodes with some difference in results noted. The effect of animal glue additions of 0.01, 0.10, and 0.50 gpl of solution on the cathodic polarization curves and the resulting deposit morphologies were determined. These glue additions correspond to 0.20, 2.0, and 10.0 pounds of glue per ton of zinc deposited, respectively. The slope of the Tafel region of the polarization curves was found to …

A Statistical Hydrologic Simulation Model, Ronald L. Wycoff

Masters Theses

"Simulation of a physical system requires knowledge of all components of the system and their interactions. A probabilistic simulation model of a hydrologic system is developed from short term continuous, sychronized rainfall-runoff records. The individual components of the system area the time between and duration of storms, the depth of rain occurring in each time period of the storm, precipitation excess relations, and the watersheds unit hydrograph. The available data is used to define or develop the probabilistic models involved. The only nonprobabilistic model employed is the watersheds unit hydrograph. It is found that the time between and duration of …

Some Metal Complexes Of Dihydroxycyclobutenedione, Stewart Michael Condren

Doctoral Dissertations

"This study involves an investigation of some of the physical and chemical properties of the trivalent metal squarate complexes of iron, vanadium, and indium in order to determine their structure. In this investigation studies were made of the infrared spectra, electronic spectra, x-ray diffraction powder photographs and diffractometer patterns, magnetic susceptibilities, and thermogravimetric patterns for the trihydrate, dihydrate, and anhydrous squarate complexes of vanadium(III) and iron (III) and the dihydrate squarate complex of indium(III). These studies suggest that the structures of the vanadium(III) and iron(III) squarate complexes are dimeric with hydroxyl bridges between the metal atoms. This is supported by …

Sediment Properties And Depositional Environment Of The Minnelusa Formation (Permo-Pennsylvanian), Northern Black Hills, South Dakota And Wyoming, El-Magtuf Taleb Taleb

Masters Theses

"Permo-Pennsylvanian sedimentary rocks of the Minnelusa Formation of the Black Hills uplift, South Dakota and Wyoming, can be divided into upper, middle and lower divisions on the basis of lithology. The upper portion of 150 to 200 feet consists of gray and yellow sandstone, with some carbonates and shales in some sections. The middle portion, about 200 to 220 feet thick consists of gray and red sandstone with carbonate members including the prominent dolomite member at the base; some of the carbonates are cherty. The lower portion, 20 to 60 feet thick, consists of pink sandstone, arenaceous dolomite and thin …

A Study Of The Void-Strengthening Of Aluminum And Its Nature, Purushottam G. Manusmare

Masters Theses

"Strengthening of aluminum by formation of the voids and the nature of resultant strengthening, viz., the temperature and the strain rate dependence of its yield strength were studied. Aluminum wires with 99.999% purity and of 3.1 mm diameter were quenched and heat treated to form voids of the approximate density 10¹³-10¹⁴ voids/cm³ and were tested for their yield strength. Voids in selected samples were observed by transmission electron microscopy using the Hitachi HU-11A microscope. The yield strength of the void strengthened samples was measured at various temperatures from 77ºK to 593ºK using two strain rates, 3.33 x 10⁻²/sec and 1.67 …

Calculation Of Eddy Current Loss Of A Disc, Kou Quen Chang

Masters Theses

"A method is presented to calculate the eddy current losses of a uniform disc with an opening in the center and excited by a circular current loopage First, the disc is subdivided into smaller concentric rings, then the self-inductances, the mutual inductances between these smaller rings, the mutual inductances between the excitation coil and the smaller rings, and the resistance of the rings are calculated. Next, the eddy current flowing in each ring is obtained by solving a complex matrix equation of the form [X] [I] = [V] where X is the impedance matrix, I is the eddy current matrix, …

Low Frequency Lumped Element Directional Couplers, Constantine Rodolph Jenkins

Masters Theses

"Lumped element directional couplers are desirable at frequencies below the VHF range because they eliminate the large physical size necessary for the distributed element directional couplers. The purpose of this work is to describe the theory and design of such low frequency lumped element directional couplers. A model for the coupler is developed and the equations which describe it are derived. Scattering matrices for one and two section couplers are obtained. Computer solutions for three section couplers are presented. Experimental results for one, two, and three section couplers are presented and comparison with theory are made. Comparisons of theoretical and …

Feed Drive Design For Numerically Controlled Machine Tools, Subash Bhatia

Masters Theses

"The various types of feed drive control systems used in numerical control of machine tools have been broadly classified. Further a step by step design has been presented for the feed drive of a numerical contouring control milling machine. The aim has been to develop a consistent strategy for tackling a variety of such problems. Consequently stress has been laid on principles and not on design figures"--Abstract, page ii.

Frequency Division Using Cascaded Phase-Locked Loops, Curtis B. Abshier

Masters Theses

"In many practical communication systems it is necessary to generate phase coherent subharmonics of an input tone. A useful system for accomplishing this task is a system of phase-locked loops in cascade. It is shown that when the feed-forward function is matched, the phase error of the second loop is zero. Analytical analysis and computer simulation prove that the minimum time to achieve phase-lock is obtained when the feed-forward function is matched. Under this condition, necessary design parameters are determined with ease"--Abstract, page i.

An Analysis Of Solar Noise Outbursts And Their Application To Space Communication, Marion Francis Moen

Masters Theses

"A relationship between sunspot activity, solar flare activity and noise outbursts is presented. Five different types of interference radiation in the 10MH_z to 30,000 MH_z frequency band are discussed. Data obtained by solar radio astronomy are analyzed to determine the extent of solar noise outbursts as a function of sunspot activity. An application of the burst data to future space communication is given"--Abstract, page ii.

Ground Water Of The Uncompahgre Valley Montrose County, Colorado, Ted William Craig

Masters Theses

"Data from water quality tests of 50 wells and from general well information of 309 wells registered with the Colorado Division of Water Resources are presented for the area of Montrose County, Colorado, drained by the Uncompahgre River. This information, along with other pertinent information such as water laws and costs, is evaluated to determine the feasibility of increasing the use of ground water in the area. The drainage basin of the Uncompahgre River within the Montrose area bas three main geologic structures: the Uncompahgre uplift, the Montrose syncline, and the Gunnison uplift. All formations exposed in the area are …

Absolute Cross Sections For Excitation Of Neon By Impact Of 20-180 Kev H , H₂ And He Ions, George William York

Doctoral Dissertations

"The technique of heavy-ion energy-loss spectrometry has been used to measure excitation cross sections for the (2p⁵)3s and (2p⁵)3p electronic configurations of Neon. The incident particles used were H⁺ , H⁺₂ and He⁺ at impact energies from 20-180 keV. The results are compared with previous optical measurements of the emission cross sections of lines from these levels as excited by H⁺ and He⁺ impact. Agreement is not good, either in shape or in absolute magnitude for excitation of the (2p⁵)3s configuration. However, agreement is surprisingly good for excitation of the (2p⁵)3p configuration. A curve fitting technique has been applied to …

Modeling The Visual Pathway For Interactive Diagnosis Of Visual Fields, Chiam Geoffrey Goldbogen

Doctoral Dissertations

"Visual fields are an important tool for the ophthalmologist in the detection, diagnosis, and monitoring of certain diseases and maladies of the visual pathway. The aim of the present research is to build a computer system which utilizes a learning machine to develop a mathematical model of the visual pathway. It is hoped that this system may be used in the field of ophthalmology as a teaching aid, or may assist in various aspects of diagnosis. Faults corresponding to blind or impaired areas of visual fields are extracted from medical records of a patient's condition. The structure of the model …

Surface Reactions Of Boron With Clean Tungsten Substrates, Thomas A. Flaim

Doctoral Dissertations

"A model developed to predict adsorbate-induced work-function changes for thermionic emitters is shown here to apply to a more general class of electron emission phenomena and a much broader range of adsorbates. This model predicts that chemically, vapor-deposited boron will increase the work function of a clean tungsten substrate at coverages between 0 and 1 monolayer. This is the first time that a single model has been shown to predict both positive and negative work function changes for different adsorbates. The reactions of chemically, vapor-deposited (CVD) boron with clean tungsten substrates were studied using field emission microscopy (FEM) and low …

The Use Of Semiconductor Memories In Drug Dispensing, James John De Largy

Masters Theses

"This paper presents the problems encountered and the methods used during the design of an electronic system to be an integral part of a medical drug dispensing machine. The system has a memory composed of both random access and read only memories to enable it to operate, along with many such machines , from one data input line. The system accepts information such as patient's name, social security number, and drug location number. It also provides signal drive to an attached printer in order to reproduce this information for use on the drug label. Finally, the system electronics accepts input …

A Software System For Interactive Man-Machine Design And Analysis Of Electronic Circuits, Leo William Midden

Masters Theses

"The development of an interactive computer-aided circuit analysis program is presented. A graphics terminal is used as an I/O device while an SCC 650 mini-computer is used as peripheral processor. The central processor is an IBM 360/50.

Formulation, capabilities and use of the system are discussed in detail. Close attention is given to user control, making the system both useful and versatile. Both hard and soft copies of all plots and tabular data are available. Provisions are made for error corrections and changes at each step of the input. Parameter values can be altered before and after each analysis.

Additionally, …

Mechanical Properties Of Low Carbon Martensite, Allen L. Affolter

Masters Theses

"Steels of three different compositions were heat treated and tensile tested in order to determine their mechanical properties after heat treatment. All samples had near 0.20 per cent carbon and two manganese levels 0.90 per cent and 1.35 per cent. One group containing the higher manganese level also had small additions of columbium and vanadium. The specimens were too brittle in the as-quenched condition to be loaded to full strength. Maximum strength and ductility were found after short time tempering at low tempering temperatures -- 2 to 15 minutes at 200º to 300ºF. Higher strengths were found at the low …

Practical Application Of Digital Computer To Distribution Systems, Juan Vincente Saavedra

Masters Theses

"Given a three phase ac power distribution system, a digital computer program is presented which determines a complete steady state solution for a given condition. The network data is processed by the computer into an admittance matrix, and these parameters are stored in a manner that enables the computer program to operate upon them as the coefficient of a simultaneous set of nonlinear equations. This set of equations are solved by the Gauss-Seidel Iterative Process improved by a modification of the relaxation method. Practical experience with the distribution system of the Davenport, Iowa, plant of the Aluminum Company of America …

Intrinsic Viscosities Of Linear Polyethylene, Joseph Shing Chiang

Masters Theses

"Intrinsic viscosity measurements were performed on linear polyethylene (Marlex 6009) in decalin at 135ºC and in diphenyl ether at 163.9ºC. Molecular weights ranging from 3x10³ to 35x10⁴ were studied. It was found that for linear polyethylene of molecular weight up to 35x10⁴, the tedious intrinsic viscosity measurement could be replaced by inherent viscosity measurement at a concentration of 0.1 grams per deciliter. The effect of shear on viscosities measured in decalin increased as the molecular weight of the sample increased. The shear rate effects on intrinsic viscosities were negligible. On the other hand, the shear rate effect on the Huggins' …

The Influence Of Member Length On Thermal Contact Resistance In A Vacuum Environment, Larry Martin Cooper

Masters Theses

"An investigation was conducted to determine the influence of member length on thermal contact resistance in a vacuum environment. A model was created which consisted of a center rod axially loaded between two other members. It was assumed that circular macroscopic constriction areas were formed at the contact interface when the rods were loaded. Macroscopic modeling of the contact surfaces makes the thermal contact analysis a function of the mechanical and thermal boundary conditions of the total body. The method of finite differences was employed to calculate the temperature distribution, heat flows, and thermal contact resistance of each member. Data …