Engineering Commons^™

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 …

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 …

The Amino Acid And Monosaccharide Content Of The Cell Walls Of Thiobacillus Thiooxidans, Edward Hibbert Crum

Doctoral Dissertations

"The objectives of this investigation were: (a) to culture large quantities of Thiobacillus thiooxidans cells, (b) to find an acceptable method of rupturing the cells, (c) to find an acceptable method of isolating the cell walls, and (d) to analyze the cell wall components, especially the amino acid and sugar components. The strain of T. thiooxidans used for this investigation was American Type Culture Collection Number 8085. The surface active agents Tergitol 08 and Tween 80 were investigated for their ability to reduce the lag period found in the growth of T. thiooxidans. Although a concentration of 12.5 ppm Tween …

A Structural Investigation Of Bismuth Ferrate And The Bifeo₃-Pbzro₃-Pbtio₃ Ternary System, Gary D. Achenbach

Doctoral Dissertations

"Solid state reaction of Bi₂O₃ · Fe₂O₃ mixtures was shown to yield impure bismuth ferrate, BiFeO₃, containing Bi₂Fe₄O₉ and residual Bi₂O₃; this places the results of much of the literature based on BiFeO₃ prepared by this technique in suspect. Single phase polycrystalline BiFeO₃ was prepared by multiple nitric acid leaching of sintered samples which contained excess Bi₂O₃ to prevent the formation of Bi₂Fe₄O₉ during sintering. X-ray and neutron powder diffraction data indicate that …

A Study Of Surface And Geometric Effects On The Nucleate Boiling Of Liquid Nitrogen And Liquid Argon From Atmospheric To The Critical Pressure, Calvin Benson Cobb

Doctoral Dissertations

"A maximum heat flux correlation was derived for corresponding states liquids and subsequently verified by the data collected in this study as well as data presented in the literature. By applying this correlation, one can predict maximum heat flux values at high pressures from maximum heat flux values measured at low pressures; however, to apply the correlation it is necessary to have at least one maximum heat flux value and the saturation temperature at which it was determined.

Contrary to existing correlations, it is shown that for any nucleate boiling heat transfer correlation to be truly general, it must include …

Tests On Light Gage Steel Diaphragms, George Winter, T. V. S. R. Apparao

CCFSS Library (1939 - present)

This report supplements and extends the scope of Report No. 319, ;lStructural Performance of Light Gage Steel Diaphragms", by Dr. Larry D. Luttrell. Eleven static load tests were conducted on 22 gage narrow rib roof decks to investigate the effect of length of the diaphragm, type of welding, and diaphragm material tensile properties on the shear stiffness and strength of the diaphragm. The behavior of a diaphragm under reversed load at two different levels) one at 0.4 x ultimate static load and the other at 0.6 x ultimate static load was explored by conducting five tests. The tests at a …

Further Studies Of The Catalytic Oxidation Of Ortho-Xylene To Phthalic Anhydride Using A Fluidized Bed Reactor., Richard Shih-Chun Chu

Masters Theses

"This investigation was conducted to further study the vapor-phase oxidation or o-xylene to phthalic anhydride in a fluidized bed catalytic reactor. Parameters investigated during the study were temperature, catalyst volume, and catalyst activated by use or different promoters. Two different vanadium pentoxide catalysts were used. One was a new catalyst(Catalyst I) supported on a silica base and diluted with potassium sulfate. The other catalyst(Catalyst II) was similar to the first one except that it had been used in a commercial fixed bed reactor operated by the Monsanto Company, St. Louis, Missouri, using naphthalene as a reed material. It had been …

Nucleate-Boiling Heat Transfer To Water At Atmospheric Pressure, H. D. Chevali

Masters Theses

"The purpose of this investigation was to study the hysteresis effect, the effect of micro-roughness and orientation of the heat-transfer surface, and the effect of infra-red-radiation-treated heat-transfer surfaces on the nucleate-boiling curve.

It has been observed that there exists no hysteresis effect for water boiling from a cylindrical copper surface in the nucleate-boiling region over the range studied. The nucleate-boiling curve has been found to be independent of micro-roughness and orientation of the heat-transfer surface. There was no detectable change in the nucleate-boiling characteristics of the heat-transfer surface when the surface was treated with infra-red radiation"--Abstract, page ii.

Electrodialysis Of Tomato Juice, Raghunath R. Khetan

Masters Theses

"Thermal decarboxylation of carboxylic acids has been helpful in illustrating some fundamentals of reaction kinetics in solution. It has been important in formulation of the theory of unimolecular reactions. It is also used frequently in the synthetical methods of organic chemistry.

In a recent study of the anodic oxidation of malonic acid in sulfuric acid at 80⁰C using a platinum anode, the interpretation of some results was impossible due to the spontaneous decomposition of the malonic acid. As no information is available in the literature about decomposition rates of malonic acid in sulfuric acid at the concentrations used, it was …

Synthesis And Structural Determination Of Intermetallic Compounds In The Fe-Ho System, Gerald J. Roe

Masters Theses

"The intermediate phases in the holmium-iron system were investigated by means of X-ray diffraction and metallographic examination. The intermediate phases identified by X-ray diffraction data were HoFe₂ , HoFe₃ , HoFe₅, and Ho₂Fe₁₇.

A new intermediate phase, HoFe₃, was found. HoFe₃ was indexed as hexagonal with lattice parameters of a = 5.084 Å and c = 24.45 Å, and was thought to be of the space group R3̄̄m.

HoFe₂ was formed by a peritectic reaction and its solidus was estimated to be between 1325°C and 1340°C. suggested to be a congruent melting intermetallic compound with a melting point below 1340°C. …

Continuously Tapered Dielectric Matching Transitions For Waveguides, William E. Hord

Doctoral Dissertations

"Dielectric matching transitions at microwave frequencies are used for matching air filled waveguides into dielectric filled waveguides for maser work or into dielectric rod antennas. Also dielectric loading has been shown to improve the performance of the ferrite isolators.

The dielectric matching transitions that have been analyzed in the literature are of the stepped type. The continuously tapered dielectric matching transitions investigated in this dissertation provide increased bandwidth with very little increase of physical complexity.

The dissertation provides an analytical method for analysis and design for the continuously tapered dielectric matching transition. First-order and second-order approximate solutions for both symmetrical …

The Anodic Behavior Of Zinc In Aqueous Salt Solutions, Yun-Chung Sun

Doctoral Dissertations

"The increasing demand for protective metals as coatings and non-corrosive alloys has caused extensive research on the fundamental behavior of metals in corrosive media. The problem of controlling the destructive process of metallic corrosion still exists and becomes urgent in this space age. The desirablity of metals such as beryllium, magnesium, and zinc in air frame and space structural units, because of their high strength to weight ratio, has been responsible for the considerable progress in their technology in recent years.

The basic mechanism of the anodic dissolution of metals such as zinc, cadmium, and magnesium in salt solution is …

An Investigation Of The Induction Heating Characteristics Of Powdered Susceptors Dispersed In A Non-Conducting Medium, Robert Leon Wright

Doctoral Dissertations

"This investigation determined some of the induction heating characteristics of powdered magnetite, iron and ferrosilicon susceptor dispersed in silica sand which had been coated with thermosetting resin. The powdered susceptor particles in the mixture were heated by the field of an induction coil, consequently heating the resin coated sand and bonding the sand grains together.

It was found that the type, relative amount,and particle size of the susceptor were important variables to be considered in the induction heating characteristics. Hysteresis losses in the susceptor particles, which are a function of the coil current, frequency, and permeability, appear to be the …

The Statistical Mechanics Of Kink Interactions, Michael Brewer Mcneil

Doctoral Dissertations

"Using a potential derived from continuum elasticity, the interactions between kinks on a dislocation line are studied as special cases of the problem of a one-dimensional system of interacting particles. By the use of constant pressure ensembles, the principal kink-interaction problems of physical interest are solved. The application of these solutions to the theoretical analyses of work hardening and internal friction is explored and comparisons made to previous work in which kink interactions were neglected; it is found that, as would be expected, variations of equilibrium kink populations with external stress cannot account for the Bordoni peak, which must therefore …

Nucleate Boiling Heat Transfer To Liquid Nitrogen At Atmospheric Pressure, Satish R. Parikh

Masters Theses

"The object of this investigation was to study the effect of micro-roughness, a thin layer of oil, and infra-red radiations on the cylindrical heat transfer surface of copper, in liquid nitrogen and at atmospheric pressure during nucleate boiling. An attempt was made to find any possible effect of orientation of the heat transfer element on nucleate boiling. A number of different runs were taken with different degrees of roughness, and different orientation positions. Nucleate boiling has been found to be nearly independent of the heat transfer surface roughness and of orientation while strongly dependent on the chemical nature of the …

Determining The Best Computational Method For Simulation, Neil Hertenstein

Masters Theses

"Two related problems are treated in the discussion. First, what is the best computational means to be used to simulate a given system? Second, if hybrid is chosen, how do we assign the problem to the different computers to realize the fullest advantage of the hybrid simulation? Most of the available information in the literature is presented in light of the above questions. It is found that, despite the lack of a precise theoretical solution, much insight can be gained into the problem. A proposed procedure for hybrid assignment and a sample problem using this procedure completes the discussion"--Abstract, page …

The Effect Of Epoxy Resin In Stone And Slag Concrete, James Chun-Min Chou

Masters Theses

"In concrete construction, the weight of the structure represents a large portion of the total load carried; thus, there is considerable advantage in reducing the weight of the concrete. To obtain this result, there are at least three approaches (1). The first method of producing lightweight concrete is by means of substituting a porous lightweight aggregate of low specific gravity for the ordinary aggregate. The second method relies on introducing large voids within the concrete or mortar mass; this is known as aerated, cellular or gas concrete. The third method is simply to omit the fine aggregate from the mix …

Minimum Cost Data Collection Techniques For Circulation Control At The University Of Missouri At Rolla Library, John Peter Shewchuk Sr.

Masters Theses

"Data collection is beginning to assume increased importance in the field of data processing. This thesis investigates a method for quantitatively selecting a portion of the library to place on an automated circulation control system that uses data collection as an entry into a data processing system.

The circulation function of the library was considered to be an inventory problem. Titles were considered as items of inventory and circulation of that title was considered to be a "sale" of that item. The IMPACT method was used to distribute items (titles) in a sample by age. Various ages were found to …

The Effect Of Moisture On The Compressive And Tensile Strength On A Variety Of Rock Materials, Richard A. Martin

Masters Theses

"The effect of moisture on the strength characteristics of rock materials has been neglected in the study of rock mechanics. This study was undertaken to determine if there was any effect on the compressive and the tensile strength of rock by varying the moisture content from an oven-dried to a saturated condition.
It was found, by testing eight different rock materials that the compressive strength per unit area decreased with an increasing moisture content. The tensile strengths per unit area, with the exception of the quartzite and the porphyry samples, also decreased with an increase in moisture content. The tensile …

Turbulence Measurements In Polymer Solutions Using Hot-Film Anemometry, Gary Kent Patterson

Doctoral Dissertations

"Hot-film anemometry was used to study the detailed structure of turbulence (intensities, energy spectra, and auto-correlations) in Newtonian solvents, non-drag reducing polymer solutions, and drag reducing polymer solutions. This was done in two smooth wall tubes with diameters of 1.0 inch and 2.0 inches. A probe traversing mechanism was used for measurements at radial positions from the center to as near the wall as possible for both the film probes (r/a=0.85 in the 2-inch tube) and the impact tubes (r/ a=0.98). The impact tubes were used to measure velocities for film probe calibration.

The solvents used in this investigation were …

A Study Of Modified Plug Designs For A Globe Valve, Robert W. Wagner

Masters Theses

"This thesis presents an empirical study of the characteristics of a cylindrical skirted disk valve used as a flow regulating device. Holes were drilled in two separate removable cylinders, which, when respectively attached to the valve plug adapter, provided control of the flow rate. These cylinders could be moved to permit exposure of more or less flow area by means of the valve stem and crank mechanism. At the closed position of the valve no holes were available for flow within the differential pressure zone of the valve, while at the full-open position all the drilled holes were within the …

Approximate Solution Of The Momentum And Energy Equations For Partially Ionized Argon, Sir-Hoi Chen

Masters Theses

"Based on available experimental data, the transport properties of partially ionized argon gas have been determined by solving the integral equations of momentum and energy conservation by an approximate method. The momentum and the energy conservation integral equations are solved simultaneously by an iteration method by assuming both parabolic and cubic velocity and temperature profiles separately. The results are compared with the case of linear velocity and temperature profiles"--Abstract, page iii.

Permeability And Additive Sorption And Extraction In Lubricating Greases, Hsiu-Hsiung Lin

Masters Theses

"An important goal in the study of lubricating greases is the determination of the mechanism of additive action in lubricating greases and the effect of additive concentration on the improvement of particular properties. As a step in this direction, one aim of this investigation was an attempt to determine whether grease additives are sorbed on the thickener surface, or are dissolved in the oil phase, or if a combination of these effects prevails. Exploratory sorption and extraction experiments were run by Tu using greases thickened with lithium hydroxystearate and Baragel and using only one concentration of additive. More detailed studies …

The Development Of A Modified Soil Shear Vane, Vernelle Truman Smith

Masters Theses

"The purpose of this investigation was to determine how the soil shear graph could be modified to measure more accurately values of shear strength of fine-grained, cohesive soils. Several modifications were tried, however, the one that gave the most satisfactory results consisted of a vane and base plate mechanism.

A red clay of high plasticity obtained from a local cave was tested in both the natural or undisturbed state and in the remolded state. The only variable was the moisture content. Compaction effort was the same for all remolded specimens. Tests were conducted on undisturbed samples taken with thin walled …

The Kinetics Of The Reaction Of M-Nitrobenzyl Bromide With Hydroxide Ion In Aqueous-Aprotic Solvent Mixtures, Ramesh Nagindas Sheth

Masters Theses

"The reaction between m-nitrobenzyl bromide and sodium hydroxide in homogeneous aqueous dioxane and aqueous tetrahydrofuran media was studied.

The product of the reaction was identified by infrared, gas chromatography and chemical tests as m-nitrobenzyl alcohol.
The kinetics of the reaction are second order with practically no variation in the rate constants as the % of the organic solvent was changed in the medium. This seems to imply hydrolysis of the organic halide by a process involving both bond-breaking and bond-formation in the transition state.
The activation energy, measured in 50% aqueous dioxane, between 20⁰ and 69.5⁰C at 5 different temperatures, …

Checking Rigid-Framed Structures By Extended Moment-Area Equations, Lucky Li-Chi Chow

Masters Theses

"Using the known moments obtained from the moment distribution solution, the extended moment-area equations are used to check whether or not delta x, delta y, delta theta are truly zero, or are any other quantity they are supposed to be. In order to get a reasonably correct answer, a solution must meet both the elastic checks and the static checks for their equilibrium and compatibility functions. Using the extended moment-area equations, the magnitudes of the slopes and deflections at all of the joints in framed structures can be found easily"--Abstract, page ii.

The Shrinkage Characteristics Of Plastic Clay, Edward De Santis

Masters Theses

"This investigation was conducted to determine the shrinkage properties of a clay soil whose structure had been artificially altered in the laboratory. Various percentages of dispersing and flocculating agent were added to the soil and the shrinkage curves plotted.

The shrinkage curves of the chemically treated soil were compared with those of the untreated soil. The values of the theoretical and observed shrinkage limits were also compared to determine the validity of the standard shrinkage limit test which, at present, does not take into consideration the structure of the soil.

An explanation of the differences in the shrinkage characteristics of …

An Investigation Of Consolidation On Compacted Partially Saturated Clarksville Soil, Ma-Tai Matthew Chen

Masters Theses

"The Terzaghi theory of consolidation and the assumption of his theory, pore pressure and effective stress, secondary compression and rheology were all reviewed and discussed. Eight compacted unsaturated samples made from Clarksville silty clay (CL) under different compaction efforts and moisture contents were subjected to consolidation load increments. Each load increment was maintained for 24 hours. An extra compacted sample was loaded for one month to investigate secondary compression.

From e-p curves, five settlement vs. compacted embankment height curves were derived for different compaction effort and moisture contents. These curves may be of practical use, when checked by field measurements …

Bending Of Isosceles Right Triangular Plates, Ping-Tung Huang

Masters Theses

"In this thesis the series expansion method is used to obtain the moments and deflections of an isosceles right triangular plate bent by arbitrary transverse loads. The method is based on using an antisymmetric load on a square plate. Two boundary conditions are solved and the numerical results obtained for these cases are tabulated"--Abstract, page ii.