Engineering Commons^™

A Study Of The Dissolution Of Zr-O Alloys In Hydrofluoric Acid, Wayne Gilbert Custead

Doctoral Dissertations

"The purpose of this investigation was to ascertain and explain, if possible, the effect of oxygen in the metal on the kinetics and electrochemistry of the reaction of zirconium in hydrofluoric acid solutions. This entailed the determination of the effect of oxygen on the dissolution rates, activation energies, dissolution potentials, and difference effect for zirconium in hydrofluoric acid and hydrofluoric-hydrochloric acid mixtures.

The alpha-phase solid solutions of oxygen and zirconium were synthesized by the powder-metallurgy technique. Both the alloy analysis and dissolution rates were obtained by the gas evolution method according to the reaction:

ZrO_x + 4HF → ZrF …

An Investigation Of The Deformation Textures Of Cobalt, Roy Carl Wilcox

Doctoral Dissertations

"Deformation textures of various cobalt structures as a result of cold rolling together with some annealing textures were studied. The textures of cobalt were determined using a modification of the Schulz-Decker Geiger counter technique. Pole figures of the (1011), (0001) and (1010) planes were constructed. Also, a study of the microhardness of cobalt was made.

Microhardness tests were performed on various cobalt structures, in both the cold rolled and unworked conditions. The microhardness was found to vary with the source of the cobalt, the crystal orientation, and the amount of deformation and twinning. Deformation lines about the hardness impressions diffused …

Statistical Analysis Of Fracture Stresses Of Triaxial Porcelain Bodies, Robert E. Moore

Doctoral Dissertations

"Triaxial porcelain bodies containing various forms of silica, quartz, cristobalite and fused silica, were strength tested in bending. Significance tests were employed to discern real differences in the strength sample statistics caused by the various forms of silica. Firings were performed at three temperature levels. The differences in strength sample statistics were correlated to the microstructures of these silica porcelains.

A triaxial alumina porcelain body was employed as a model brittle solid for a study of the effect of flaw density on mean fracture stress. The flaws were introduced in the form of large diameter (d̄ = 115 microns) rounded …

Lattice Parameters, Densities And Imperfections In Indium And Indium-Cadmium Alloys Rich In Indium, Paluri Bhimeswara Rao

Doctoral Dissertations

"An investigation of perfection of the structure of the indium-cadmium system was suggested by the interesting properties of indium and its cadmium alloys. The lattice of indium, though tetragonal, may be considered as distorted cubic, its axial ratio being 1.0767 at 20°C. Furthermore earlier studies have revealed a transformation of the tetragonal structure to cubic in the presence of cadmium.

To determine the perfection or soundness of the indium and indium-cadmium alloys rich in indium, pure indium (99.999 per cent purity) and eight samples of the indium-cadmium alloys ranging in composition from 2.977 to 10.015 per cent by weight of …

An Investigation Of Indeterminate Structures Stressed Beyond The Proportional Limit, Jack B. Joyce

Civil Engineering ETDs

In the structural field the methods of designing have been geared to the development of materials...In a more current appraisal we see steel and concrete being updated still further. Pre-stressed concrete is a common sight in present day construction work and, to a lesser extent, the educated eye sees rigid frames designed to ultimate load criteria. Here again are cases where materials are studied and found to possess characteristics that are adaptable to advance methods. The key to all such improvements is still the realization and utilization of material properties.

Heat Transfer Coefficients Of Non-Newtonian Slurries In Laminar Flow, Robert Frederick Roth, David B. Swanson

Theses

A total of 51 heat transfer runs were made in the first 25 runs, slurries of half micron and finer kaolin at 3.0, 5.6, 9.6 and 12.9% solids were used. Slurries of two microns and finer kaolin at 10.1, 13.7, 20.4 and 23.1% solids were used in the remaining 26 runs.

The Reynolds Numbers ranged from 0.9 to 2,020 for the 51 runs.

The data was correlated by the following equation:

H_f/C_bV_bP_b C_bR_b/K_b ^2/3 = 0.70 DV_bP_b/R_b ^-2/3

for an L/D ratio of …

An Acoustic Simulator For Modeling Backscatter Of Electromagnetic Waves, Allen R. Edison

Electrical and Computer Engineering ETDs

Model experiments are commonly employed in situations where a full-scale experiment is uneconomical and where exact theoretical analysis is very difficult. The physical problem is scaled to convenient laboratory dimensions and a means is provided for controlling and measuring the parameters of the experiment. Measurements made in the model system are required to provide information on the time and space variations of functions which describe the real system. When interpreting results it is frequently necessary to consider "scale effects" which arise from certain parameters exerting a different influence in the model than in the real system.

Propagation Between Conducting And Nonconducting Media, Richard H. Williams

Electrical and Computer Engineering ETDs

This paper contains a study of the electromagnetic fields caused by electric dipoles located within a highly conductive medium such as the sea. The theoretical treatment of this problem was begun in 1951 with Moore's thesis. "The Theory of Radio Communication between Submerged Submarines." Some subsequent major theoretical treatments of this problem have been published by Wait and Campbell, Lien, Banos and Wesley, and Anderson. All of the above work stems from Sommerfeld's classic paper published in 1909 where he considers the fields in the air caused by a vertical electric antenna located on the interface between the air and …

An Investigation Of The Behavior Of Asphalt Stabilized Sand In Triaxial Compression Testing, Joseph P. Callahan

Civil Engineering ETDs

More and more in highway construction, the engineer is faced with the problem of locating satisfactory materials to be used in the construction of highways. This problem has become very critical in the selection of a satisfactory aggregate to be used in many phases of the construction. In large metropolitan areas and in other regions of the United States unblessed with an abundance of this aggregate, it was found that where once there was no shortage of suitable material, the supplies have now been practically exhausted.

A Study Of A Nonlinear Compensation Network In A Feedback Control System, John F. Taylor

Electrical and Computer Engineering ETDs

This paper is a study of the effect of a nonlinear compensation network on the closed-loop response of a feedback control system.

Physical energy dissipation elements, unlike their usual mathematical models, are often nonlinear. An example of such a nonlinear element is the mechanical damper. Since dissipation elements are used in most types of compensation, the problem of nonlinear compensation is an important one.

The study was performed with two goals in mind. The first was to determine the detrimental effects resulting from the insertion of the nonlinear network. The second was to see if any improvement in system performance …

A Shell-Theory Analysis Of Transient Thermal Stresses In Moderately Thick-Walled Cylinders, Thomas K. Mckinley

Mechanical Engineering ETDs

This paper investigates the validity of extending the concepts of shell theory to transient thermoelastic problems involving moderately thick-walled shells. The region of study is a moderately thick-walled cylinder which is constrained radially at both ends and is exposed to a uniform, time-dependent heating (or cooling) at one end. The cylinder walls are assumed to be adiabatic, and inertia effects are neglected in the development.

It is concluded from the results of this investigation that the extension of shell theory to moderately thick-walled cylindrical regions subjected to axial, time-dependent temperature variations is an analytical method of approach.

Investigation Of The Platinum-Rich Portion Of The Platinum-Tantalum Phase Diagram, Bob Dean Browning

Theses and Dissertations

The Pt-Ta binary system was investigated at two isotherms;1000°C and 1500°C, and at eleven alloy compositions in the range of 50 to 100 atomic percent platinum. The alloys were examined by x-ray diffraction and metallography. Three intermetallic compounds, Pt₂Ta, Pt₃Ta, and Pt₄Ta were found to exist in this composition range. The Pt₄Ta intermetallic appeared only at the 1500°C isotherm. Platinum dissolved tantalum substitutionally to 90 atomic percent at 1500 °C and to approximately 80 atomic percent at 1000 °C.

The Design Of A Six Specimen Tensile Fatigue Machine, Charles Mark Percival

Theses and Dissertations

Although metal fatigue has been recognized for many years and during that time many persons have tried to find the explanation for it, there is still not a complete theory concerning this phenomenon. Metal fatigue is one of the major problems the modem designer must face. If the design techniques are to progress as other technological advances are made, it is evident that it will involve a better understanding of metal fatigue.

Design Of An Air Stabilized Plasma Arc, William Robert Clarke

Theses and Dissertations

The plasma-arc generator (see figure 1, 2) has been used for several years as an invaluable ground test facility in which the gas stagnation properties of hypervelocity flight may be reproduced. The plasma is produced by shorting an electric arc between two electrodes; then directing a gas stream through the arc. The gas stream is thus heated to a ''temperature " of forty to fifty thousand degrees Farenheit. At this temperature the gas is in a state of partial ionization termed "plasma". The plasma stream is then constricted and directed by a nozzle into a test chamber and over the …

Analysis Of Radio Wave Propagation Over An Atmospheric Ground Layer By The Ray Tracing Method, Donnelly J. Johnson

Electrical and Computer Engineering ETDs

Previous efforts to analyze radio wave propagation in the troposphere have shown by agreement with experimental results the validity of the use of geometrical optics and the assumption of atmospheric spherical symmetry.

The Effect Of Velocity On The Electrical Conductivity Of Blood, Judea Pearl

Theses

Although the change in the conductance of blood resulting from changes in its velocity has been noted by several investigators working with electrical impedance techniques, this parameter of measurement has heretofore not been investigated from the viewpoint of practical application to blood flow measurement.

In certain regions of the body such as the tooth pulp and the cranial cavity, the volume of the contained blood cannot fluctuate during a cardiac cycle because of the rigid wall of the chamber. Therefore, impedance pulses which have been obtained in studies on the tooth pulp, must be attributed to the rhythmical fluctuation of …

Catalytic Activity Studies In Aromatic Sulfonation, William Marvin Jayne Jr.

Theses

The object of this investigation has been to determine the catalytic activity of several inorganic materials in promoting the sulfonation of aromatic organic compounds. Initial work involved sulfonation of p-nitroaniline with an excess of sulfuric acid. However, due to insufficient precision of the method of analysis, this system was abandoned. Thereafter, the study was concerned chiefly with the benzene and other aromatic compounds in nitrobenzene solution. This phase of the work proved to be successful, and the results are reported in the text of the thesis.

The author gratefully acknowledges the suggestions and counsel given throughout these investigations by Professor …

The Electrolytic Oxidation Of Para-Nitrotoluene, Mustafa Darwish Shamy

Theses

The factors affecting the electrolytic oxidation of p-nitrotoluene to p-nitrobenzoic acid have been studied, and optimum conditions determined for obtaining the best overall yield of 65.7 per cent. These Anode:lead sheetCathode:lead sheetAnolyte:250 cc of 50 per cent sulfuric acid
10 grams of p-nitrotoluene
5 grams of chromic trioxideCatholyte:250 cc of 50 per cent sulfuric acidVoltage:4.5 ± .5 voltsCurrent density:3.0 amperes per square decimeter.Temperatures65 ± 3°CReaction time:fifty per cent of the theoretical time required

It was observed that high potentials and prolonged reaction periods are detrimental to the yield.

A mechanism for the electrolytic oxidation process is suggested, based on experimental …

Surface Area Of Small Particles, Richard Henry Ullrich

Theses

Experiments using glass beads and water were performed to obtain data to relate evaporation rates with the total surface area of a small sample of particles. The object of this work was to explore the possibility of devising a new method of determining surface areas which would be simple, rapid and non-destructive.

One gram samples of glaze beads ranging in diameter from 840 to 150 microns were wet with water and dryed to constant weight under controlled conditions. Residual water was removed by continued heating at a higher temperature. The experimental conditions were deliberately simple in keeping with the purpose …

Investigation Of The Stability And Response Of A Reboiler Under Condensate Control, Francis Arthur Winter

Theses

Control of heat flux by condensate throttling was investigated theoretically by frequency response analysis and experimentally on a simulated reboiler control system.

Transfer functions were derived for each component and ware used to describe the response of the experi- mental system. Experimental controller settings were in reasonable agreement with the calculated results. However, general overall control was poor because of dead time and cyclic disturbances. Experiments showed that the process contained dead time in the order of three to seven times the ultimate period (0.5 - 1.0 minutes). Several sources of disturbances prevented an accurate evaluation of stability at low …

Physical And Electrical Properties Of The Manganin-Type Alloys, Wallace William Macintosh

Theses

This thesis is a report on the physical and electrical properties of the manganin-type alloys as compiled from the published literature on the subject. The peculiarities of these alloys, as related to mechanical history, heat treatment, and composition, are discussed. Empirical formulae, by which the temperature coefficient of resistance, the temperature of maximum resistance, the temperature-resistance equation, and the thermoelectric emf of these alloys against copper may be calculated, are shown.

A comparison of the effect of elongation on the specific resistivity of several sizes of manganin wire is made on the basis of experimental results. The effect of impurities …

The Electrolytic Preparation Of Perbromates, Robert M. Casciano

Theses

Since perchlorates and periodates can be formed by the electrolytic oxidation of chlorate and iodate solutions and since bromine lies between chlorine and iodine in the periodic table, it should be possible to electrolytically prepare perbromates. As yet, however, perbromates have not been prepared by any methods.

It was desired to attempt to prepare perbromates electrolytically and to definitely show their presence or absence after electrolysis. In order to accomplish this a new method of analysis was developed.

This work has shown that perbromates cannot be prepared by the electrolytic oxidation of bromate solutions under various conditions of temperature, current …

Effect Of Elevated Temperature On Efficiency Of Corrosion Inhibitors, Walter Dzingala

Theses

An experimental program was set up to investigate the effect of temperature on the protection efficiency of various inhibitors of metal corrosion. Contrary to most studies, an appreciable amount of the work was done with the corrosive effect being determined on the metal specimens that were exposed first to the inhibitor, then to air at different temperature, and finally to the corrosive medium with no inhibitor present. The purpose being to determine whether the inhibitor treatment would provide a permanent protection for a metal surface or would it be necessary to furnish a continuous supply of the inhibitor to the …

Extrapolation Of Viscosity Data For Liquids, Julius Irwin Gnapp

Theses

The method of finite-difference recurrence relations* is here applied to viscosity-temperature data to determine whether it offers an improved means of extrapolating such data. The best of the existing parametric correlations, which is considered to be that of Andrade, was found to be subject to important departures from linearity and dependent upon the particular data points used in its formulation. The proposed method is non-parametric in that it does not require an assumption of the explicit function relating viscosity with temperature. Instead, it assumes that there is a linear relation between successive values of viscosity at equal intervals of temperature. …

A Simplified Procedure For Diffusion Coefficients From Cation Exchange Studies, Robert Peter Lanyon

Theses

The purpose of this investigation was to extend the data and to improve the procedures of previous investigators (1), (2), and (3), in the study of diffusion coefficients in aqueous media.

The main contribution of this investigation is the elimination of the tedious work of size grading, drying, weighing, and rehumidification of the Dowex 50 W - X8 resin, which is used to determine the ion exchange rates for the cations under consideration, The simplified procedure measures the resin volume by displacing a known volume of water. The method of calculating diffusion coefficients follows the procedure of (1), (2), (3), …

Binary Vapor Liquid Equilibria Isobaric Systems, Ira Lichtenstein

Theses

Oalculations of activity coefficients for thirty isobaric binary systems from vapor-liquid equilibria data were made using the Gilmont equation© An extensive literature survey showed the Gilmont equation provides an excellent means of correlating equilibrium data in most binary isothermal systems° However, the Gilmont equation’s applicability to isobaric systems had not been satisfactorily proven, and became the object of this investigation.

The Gilmont equation gave satisfactory correlation of the binary isobaric data for various systems. The correlation was found to improve as the systems approached ideal behavior. The introduction of a temperature correction to the relative volatility, term improved the correlation …

Hydraulic Characteristics Of Showerdeck Trays, Sam Gordon Marx

Theses

The hydraulic operating characteristics of the showerdeck tray were investigated. Air-water studies were made using a four plate, 11 1/4 inch I. D. plexiglas column.

Entrainment, liquid froth height, and pressure drop data were obtained at varying liquid and vapor rates.

Entrainment was found to be a function of the plate spacing, liquid height on the tray, the liquid rate and the column vapor velocity. It was found to be independent of the vapor velocity through the perforations. An equation of entrainment as a function of these variables was derived.

The liquid froth height on a tray was found to …

Fugacity Coefficients Of Gases In Binary Mixtures, Louis David Mazzeii

Theses

A method of Pitzer for predicting component fugacity coefficients of gases in binary mixtures is evaluated by calculating 2100 fugacity coefficients and comparing the results to experimental data.

Pitzer employed the technique of Gamson and Watson in deriving an expression for fugacity coefficients. The expression is based on a three parameter corresponding states theory set of equations, and a definition of pseudo critical properties of mixtures, both previously proposed by Pitzer.

A further comparison with values calculated by similar methods of Edmister and Ruby, and Redlich et al (which previously were established as the most accurate general methods) indicates Pitzer's …

Electrolytic Amalgam Reduction Of Cinnamic Acid, Alan Ira Mytelka

Theses

The use of sodium amalgam and potassium amalgam to reduce cinnamic acid to hydrocinnamic acid was accomplished in two concentrically constructed cylindrical cells.

In the outer cell, liquid amalgam was prepared electrolytically using a mercury cathode. The amalgam was moved by a rocking motion into the inner cell where the cinnamic acid dissolved in ethanol was reduced to hydrocinnamic acid. The actual percent conversion as measured by iodine numbers varied from 6.0% to 567, the percentage depending upon the number of coulombs passed into the electrolytic cell, the amalgam used, and whether or not stirring in the inner reduction cell …

Thermodynamic Properties Of Hydrazine, Michael Perlswieg

Theses

The thermodynamic properties of hydrazine have been evaluated for the saturated region and for the superheated vapor. The superheated vapor properties were determined for temperatures up to 2200°F and pressures to 3000 psia. Enthalpy, entropy, and specific volume are reported for the saturated vapor and liquid and the superheated vapor. Results are reported in the form of tables.

Enthalpy values are relative to the saturated liquid at 32°F. Entropy values are absolute. The thermodynamic properties have been based on experimental data where possible. Due to the lack of experimental pressure-volume-temperature data, however, the generalized correlations of Lydersen, Greenkorn, and Hougen …