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Stress Analysis Of A Wall Footing Subjected To External Vertical Loads And Overturning Moments By The Finite Element Method, Adil Godiwalla

Masters Theses

"This investigation pertains to the stress analysis by the finite element method of a wall footing subjected to external vertical loads and external overturning moments. This problem has been reduced to a two-dimensional stress analysis problem by taking a unit length of the wall. A rectangular plate - element is used throughout this investigation. The development of the matrix equations is shown and the solution is performed by digital computer. Stresses in the horizontal direction show essentially linear variation which is in agreement with simple structural theory, while stresses in the vertical direction show severe perturbation near the column load. …

Mode Analysis Of The Unsymmetrically Fed Ground-Plane Aperture, John G. Hemmann

Masters Theses

"The problem of radiation from a waveguide-fed ground-plane aperture perturbed with a wedge-shaped dielectric insert was examined more carefully. The work initiated by Blumberg was continued, using a greater range of dielectric constants and smaller increments of angle.

Aperture field measurements were made over a range of dielectric constants for each wedge angle, in order to determine the change in amplitude distribution as a function of permittivity. Aperture phase measurements were also taken for selected angles. These were used with the amplitude data to predict, using numerical integration, the far-field radiation patterns of the perturbed aperture. Far-field patterns were then …

Study Of Mass Transfer Through Porous Water-Repellent Membrane As A Function Of Membrane Thickness And Rates Of Heating, Yalamanchili Babu Rao

Masters Theses

"The object of this investigation was to study the mass transfer coefficients through porous water-repellent membranes, and their dependence on membrane thickness and rates of heating, and to compare experimental correlations with theoretically based equations. The membranes used during the experimental work were made of glass fiber treated with Teflon suspension and aluminum sulfate. The mechanism involves evaporation and condensation on opposite sides of a vapor-filled porous membrane. Salt water evaporates from one interface of a non-wettable, porous membrane, diffuses through the vapor filled pores, and condenses to fresh water at the other interface of the membrane. This transfer may …

Molecular Diffusion In Polymer Solutions By A Microinterferometric Method, Surendra V. Desai

Masters Theses

"The object of this investigation of molecular diffusion in aqueous polymer solutions was to study the effect of solute concentration on the differential diffusion coefficient and also to study the effect of polymer concentration on the mean integral diffusion coefficient. For this purpose a microinterferometric method was used. Two non-ionic, water soluble polymers, Carboxymethylcellulose (CMC) and Carboxypolymethylene (Carbopol), were used in the study with D-Glucose as a solute.

The differential diffusion coefficient was found to increase with increases in solute concentration in all cases. For CMC, the integral diffusion coefficient at first decreased with increasing polymer concentration but became constant …

Mineralogy And Paragenesis Of The Cave-In-Rock Fluorspar District, Hardin County, Illinois, Daesuk Han

Masters Theses

"The paragenesis of minerals occurring in the bedding-replacement fluorspar ores in the Crystal, Minerva No. 1 and Hill mines in the Cave-in-Rock district, Hardin County, Illinois, has been studied by underground, binocular, petrographic and ore microscopic examination. More than 300 hand specimens were collected from the mines, 100 thin sections were prepared and 36 polished surfaces were examined to prepare paragenetic diagrams for the Crystal and Minerva No. 1 mines.

The minerals determined in the fluorspar ores were: fluorite, sphalerite, galena, chalcopyrite, pyrite, marcasite, calcite, strontianite, witherite, barite, quartz, dolomite, oil and bitumen. Most of these minerals are present both …

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 …

An Investigation Of The Reaction Of Benzhydryl Chloride With Potassium T-Butoxide In Dmso, Lawson Gibson Wideman

Masters Theses

"The ultimate aim of this study was to elucidate the mechanism of formation of tetraphenylethylene from benzhydryl chloride and potassium t-butoxide in dimethyl sulfoxide. The development of a suitable technique for following the reaction rate and of an analytical method to determine the extent of the reaction became an important object in this project"--Introduction, page 2.

Dynamic Response Of A Simply Supported Beam To An Accelerating Point Load, Joseph Victor Cusumano

Masters Theses

"An analysis based on linear theory is presented for determining the dynamic response of a simply supported beam on an elastic foundation acted upon by a moving time dependent point force with axial forces included. This thesis extends the present theory to include an analysis of a point force accelerating uniformly across the beam. In particular, it is shown that the customary resonance conditions which are prevalent for a point force moving with uniform velocity no longer exist for the case of a point force accelerating uniformly across the beam.

The basic problem and its solution are presented for a …

Mechanisms Of Base-Catalyzed Reactions: Part Iii: The Acidities Of Some Hydroxylic Compounds In T-Butyl Alcohol., Charles Frederick Seger

Masters Theses

"The K_HA of water and five alcohols were determined in t̲-butyl alcohol employing sodium and potassium t̲-butoxides. The order of acidity is methanol>water>ethanol> 2-propanol~cyclohexanol>methanol. It was also shown that potassium t̲-butoxide was twice as strong a base as sodium t̲-butoxide. A spectrophotometric method was employed with p-nitroaniline as the indicator. Calculations were made employing the methods of Stearns and Wheland and of Hine and Hine"--Abstract, page iii.

Centrifugal Model Study And Finite Element Analysis Of Stress Near A Fault, Christopher Haycocks

Doctoral Dissertations

"The adverse effects of faults on the stability of underground openings has long been realized. To date, however, discontinuities and most other types of geologic heterogeneities have not been amenable to mathematical analysis using the classical theories of elasticity and plasticity. This investigation examines the stress distribution around a single discontinuity and compares the experimental and numerical methods used for the analysis. The theory of elasticity, employing the equations of compatibility, equilibrium etc., was used to determine a stress function for the stress distribution around a circular hole loaded in a centrifugal field. The analysis was terminated after the stress …

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 …

Matrix Computer Analysis Of Curvilinear Grid Systems, David Leon Fenton

Doctoral Dissertations

"A general equilibrium-stiffness method of matrix structural analysis was adapted and applied to the solution of the member end forces and moments of each of the members in a curvilinear structural grid system. A structural system of this nature is commonly used as the supporting framework for a "steel-framed dome", in addition to being a basic structural component in many aerospace applications. An integral part of the development of the analysis was the development of a computer program to perform the many complex operations required to obtain the solution. The engineer, by supplying the appropriate structural data and load data …

Determining The Transfer Matrices Of Tapered Multiwire Transmission Lines, Clyde A. Vandivort

Masters Theses

"The advent of monolithic and integrated microelectronic circuits has aroused interest in passive multilayered thin film networks. The basic thin film network is shown in Figure 1. This structure consists of alternate resistive and dielectric layers sandwiched together. Such devices are referred to as distributed parameter RC networks. The reduction of volume and increased reliability offered by thin film devices has caused considerable effort to be extended in the analysis of their characteristics....

The incremental equivalent circuit given in Figure 2 stems directly from the above physical parameters and is the circuit used as a basis for the analysis that …

Basic Iron (Iii) Alkanoate Complexes, Young Hee Kim

Masters Theses

"Much information appears in the literature concerning the preparation, properties and structure of the basic iron (III) acetates...This study was initiated to prepare a number of the basic trinuclear iron (III) alkanoate complexes and to investigate the possibility of a common structure for all of these as suggested by the work of Orgel. The structural investigation was done on the basis of stoichiometric relationships, infrared spectra and magnetic moments"--Abstract, pages ii-iii.

Construction Of A Laboratory Type, Convertible Excitation Argon Laser, Arthur P. Reckinger

Masters Theses

"The purpose of this thesis is to describe the construction of a general purpose, convertable [sic] excitation, laboratory type, argon laser. Quartz tubing was used in the final model while attempts to use alumina were made during earlier work. The final model has total optical power output of 230 mw at a discharge current of 29 amperes in the dc excitation mode. Provision was also made to utilize RF or pulsed excitation. The device is built so that several values of optical transmittance are available with a wide range of mirror placement"--Abstract, page ii.

Scanning Properties Of Unsymmetrically Loaded Aperture Arrays, Gary Dean Brunner

Masters Theses

"Radiation patterns resulting from an array of waveguide-fed apertures, filled with assymmetrically [sic] cut dielectric inserts, in an infinite ground plane were investigated. The results of Blumberg and Hemmen concerning single apertures were applied to a two-aperture array, with emphasis upon obtaining an array capable of scanning in the far field through changes in the permittivity of the assymmetrically [sic] cut dielectric inserts. Scanning was shown to be possible with up to a 60⁰ scan angle with a "push-pull" method of varying permittivities, in which the permittivity of one insert is raised while the other is lowered. The aperture field …

Noble Gases In The Earth And Its Atmosphere, Robert Anthony Canalas

Masters Theses

"Abundance of noble gases extracted from Fig Tree Shale exhibit a marked deviation from the gas content of eclogitic rocks purported to be mantle material. The abundances of the heavy noble gases in shale were found to exceed the highest known meteoritic values. The abundances of the lighter noble gases were found to be comparable to the abundances of these gases in typical chondrites.

Temperature gradient analyses show that excess heavy gases are released at low temperatures. This is interpreted to indicate a preferential adsorption of the heavy noble gases on fine-grained sediments when these gases were being released from …

A Subsurface Geologic Study Of Petroleum Possibilities In The Pennsylvanian Rocks Of Concho County, Texas, Gregory Paul Kraus

Masters Theses

"During early Pennsylvanian time the area now occupied by Concho County was a portion of the Texas peninsula, a broad, low arch with a karst topography developing on its exposed Ellenburger surface. A mid-Pennsylvanian marine transgression inundated the arch and it became an area of clear, shallow water deposition favorable to limestone development. Local sedimentation during Strawn time was largely controlled by its position relative to the Llano uplift and surrounding basins. A variety of subsurface maps were constructed for this study essentially utilizing electric log data. The results indicate that limestones of the Strawn platform facies rapidly change in …

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 …

A Plastic Stress Analysis Of Cylindrical Wafers Under Elastically Deformable Compression Plates, Robert L. Davis, J. W. Jackson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper represents an analysis of the pressure distribution occurring in axially loaded cylindrical wafers with, and without, elastic radial constraints. The purpose of this report is to demonstrate the resulting stress patterns that occur in short compression specimens frequently used in determining material properties, and in the opposed-anvil, or Bridgman-type, high-pressure cells. The influence of radial constraints, material strain hardening, wafer diameter-to-height ratio, anvil or plate deflection, and the wafer-anvil interface friction on the resulting stress distributions have been examined. The integrated normal stress distribution across the specimen surface has been verified experimentally via numerous tests in which each …

Dynamic Response Of Plates Due To Moving Loads, Theodore F. Raske, Alois L. Schlack

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An analysis based on linear theory is presented for determining the dynamic response and the conditions of resonance for a simply supported rectangular plate acted upon by two types of moving loads corresponding to: (1) a point force of variable magnitude oscillating about a fixed position on the plate, and (2) a point force of constant magnitude traveling in a circular orbit about a fixed position on the plate. In addition to the ordinary resonance as produced by a variable magnitude load concentrated at a fixed position on the plate, resonance of the plate may occur due to the changing …

Handlos And Baron Model: Short Contact Times, J. Patel, Robert M. Wellek

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

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.

The Anodic Dissolution Of Cadmium, James W. Johnson, E. Deng, S. C. Lai, William Joseph James

Chemical and Biochemical Engineering Faculty Research & Creative Works

The anodic dissolution of cadmium has been studied in aqueous solutions containing Cl−, Br−, I−, Ac−, SO₄=, and NO3− ions. The normal valence (+2) was found in all solutions with the exception of NO₃−. The apparent valence (calculated) of cadmium ions in nitrate solutions varied from 1.2 to 2.0 and was found to be a function of NO₃− concentration, current density, and temperature. An anodic dissolution mechanism has been proposed involving local corrosion and disintegration of the anode which is consistent with the experimental results. © 1967, The Electrochemical Society, Inc. All rights reserved.

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

Chemistry Faculty Research & Creative Works

No abstract provided.

Anodic Dissolution Of Zinc In Potassium Nitrate, Martin E. Straumanis, J. L. Reed, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

The apparent valence of pure zinc dissolving anodically in 3% KNO₃ was determined as a function of current density, temperature, and ultrasonic agitation. The apparent valence of zinc dissolving anodically at 24°C diminishes from 2.01 ± 0.01 at low current densities to 1.86 at about 50 ma and remains fairly constant up to about 80 ma cm−2. This valence is affected to some extent by the preparation, e.g., polishing of the electrode, but is independent of its structure (mono- or polycrystal). Ultrasonic vibrations do not influence the apparent valence at high current densities. In all cases a black film …

A Calorimetric Study Of The Effects Of Surface Energy In A Type Ii Superconductor, Robert Rex Rice

Doctoral Dissertations

"A calorimetric study of the effects of the interphase surface free energy has been conducted on ellipsoidal samples of first and second kind superconductors. The measurements were performed using a specially designed magnetization calorimeter by two different techniques. The measurements were made on lead, tin, lead-4at%thallium, and tin-6at% indium. The results confirm the existence and experted sign of the surface energy in a well annealed lead-4at%thallium sample, and indicate that the interphase surface energy in lead and tin is too small to be directly detected by this method. The measured latent heats of transition of lead and tin agree well …

The Relation Of Heat Transfer To Mass Transfer In Vaporization Through Porous Membranes., Chung-Liang Yeh

Masters Theses

"The object of this investigation was to study the mass and heat transport phenomena through porous, water-repellent membranes. The investigation concerned the rate of vaporization of salt water at a porous membrane surface, mass transfer of vapor through the pores of the membrane, condensation of vapor on the other surface of the membrane in contact with a coolant (fresh water), and the undesired heat transfer by conduction through the membrane. The water-repellent membrane separated the two liquid phases by surface tension forces and provided a vapor phase in its pores. Membranes made of fiberglass and Teflon had been found suitable …

Mass Transfer From A Torus Shaped Body, Kamalesh Suryakant Desai

Masters Theses

"A mathematical model for molecular diffusion in a torus was derived. Handlos and Baron have assumed a system of tori in their eddy diffusion model for liquid-liquid extraction from droplets. However, the effect of torus curvature was neglected in their studies. Since they assumed the torus could be represented by an infinite cylinder. In this study, the effect of torus curvature was considered on the concentration profile and the fraction of the solute extracted. The partial differential equation describing the model consists of three independent variables, and a finite difference technique was employed for the solution of the mathematical model. …

Plastic Deformation Of Thin Plates With A Spherical Indenter, Benjamin Jen-An Chang

Masters Theses

"A method of determining the stress distribution in a thin plate deformed with a spherical indenter is presented in this report. The analysis is formulated in cylindrical coordinates and utilizes the basic principles of plasticity (von Mises yield criteria, Luwig stress-strain equation, Hencky Deformation theory, etc.). The problem is solved through the utility of a displacement function that, by virtue of its definition, automatically assures that the condition of volume constancy is satisfied. The boundary conditions are selected on the basis of having average, or integrated, effects corresponding to the physical constraints of the problem. Numerical integration is introduced to …