Engineering Commons^™

A Study Of Electro-Magnetic Wave Propagation In Inhomogeneous Media, Thomas N. C. Wang

Electrical and Computer Engineering ETDs

The central problem of this work will be the development of several approximation methods and the application thereof to the solution of second order linear differential equations which arise in connection with the propagation of electromagnetic radiation in inhomogeneous media. Chapter I is an introduction to the problem. Maxwell’s equations are written down and it is assumed that both σ, the conductivity, and ɛ, the permittivity, are scalar functions or position. Often the above function characterizing some or the properties of matter vary in physical situations. For example, in waveguides, there may be inserted layers of dielectric material along the …

The Multi-Terminal Hall Generator, Sang S. Pak

Electrical and Computer Engineering ETDs

This thesis describes a study undertaken to maximize the Hall generator efficiency. A mathematical solution is obtained for a multi-terminal Hall generator, and an analytical technique is developed for determining the optimum values of parameters to maximize the generator efficiency. An equivalent circuit is developed for an N output-terminal Hall generator, and the efficiency expression is obtained as a function of sample dimension, conductivity and Hall coefficient of the material, and magnetic field strength. Some of the results have been checked experimentally with indium antimonide and fields up to 21.5 kilogauss. An efficiency of 40% was obtained experimentally for a …

Salt Effects In Liquid-Liquid Equilibria, Edwin Otto Eisen

Dissertations

The effect of lithium chloride, sodium chloride and potassium chloride on the distribution of acetic acid, propionic acid and butyric acid between benzene and water at 25° C has been studied. The method of Hand, which has previously been used to correlate tie line data in salt-free ternary systems, has now been successfully employed to correlate distribution data for quaternary systems containing salt.

The slope and intercept of the Hand equations have been expressed as linear functions of the salt concentration in each system studied. Equations for slope and intercept possessing high statistical significance have been formulated using a linear …

Mass Transfer Into Cylindrical Liquid Films Measurement Of Liquid Diffusivities, Ronald Francis Lovenguth

Theses

This thesis was undertaken to augment and validate the previous work of Ratcliff and Reid⁽⁷⁾ in the area of diffusion of immiscible liquids. Their novel approach to this particular problem of liquid diffusion led the author to consider an experimental technique that has been used in gas-liquid studies. A short vetted-wall column was used to determine the rate of mass transfer of benzene and toluene into thin cylindrical films of water. A general analytical solution for the rate of mass transfer has been derived and is given below. This solution was checked using the system benzene-water.

G=3.63(Π(ρ_ω-ρ …

The Virial Equation Of State Based On Critical Constants, Ghanshyam R. Patel

Theses

Results obtained from the Epstein equation of state¹⁵ i.e. equation (8), which is theoretically valid up to the critical density, are compared with the experimental values of the compressibility factor. The calculated values of compressibility factor or ethylene, ethane, propane, and n-butane were obtained using two methods of evaluation for the second and third virial coefficients. In addition, using these two methods and excluding fourth, fifth, and sixth virials in the Epstein equation of state, compressibility factors were calculated for all the four compounds to test the effect of higher virial terms. In the proposed method-(A) and method-(C), the …

Esterification Of Oleic Acid With Oleyl Alcohol, Robert Persurance

Theses

The esterification of oleic acid with oleyl alcohol was studied. A literature search showed that the chemical kinetics for this reaction had not been studied previously.

In the temperature range of 150 to 200°C. and up to a conversion of about 85 per cent, the esterification was found to be a second order reaction when the water of reaction was removed from the system by simple distillation.

Para-toluenesulfonic acid is an effective catalyst for this system, and the observed specific rate constant is a linear function of the catalyst concentration.

The effect of temperature on the specific rate constant for …

Thermal Conductivity Of Solid Materials, Irwin N. Huppert

Theses

A literature search on the methods of determining the thermal conductivity of solids has been made.

A compilation of the various methods of determining the thermal conductivity of solids presented in the literature is given in the report. In general, the literature is lacking in correlations of thermal conductivity with other properties of solid materials. A review of the correlations found is presented. A summary of data presented in the literature is presented in the text.

A method of determining the thermal conductivity of solid materials without measuring the heat flow through the test specimen is presented. The use of …

Polypropylene Fibers, Anthony Vincent Galanti

Theses

One of the latest members of the rapidly growing therrnoplastic polymer family which appears capable of successfully competing with the currently saturated textile and chemical markets is polypropylene fiber. The objectives of this Thesis were to: (1) examine the effects of polymer characteristics and fiber processing conditions on the properties of polypropylene fibers, and (2) correlate all existing information on the physical, chemical, and mechanical properties of polypropylene fibers and comparatively evaluate this material with other fibers, natural and synthetic.

Polypropylene is the first member of a new group of polymers prepared by a mechanism defined as "stereospecific" polymerization. From …

An Experimental Investigation Of The Effect Of A Constant Body Force Field Upon The Drag Coefficient Of A Sphere, Brent Evans Boyack

Theses and Dissertations

The object of this thesis was to present the method and results of an experimental determination and correlation of the drag coefficients of accelerating spheres.

A Kerr Cell System For Measuring The Amplitude Of High-Voltage Nonrecurring Pulses, Donald C. Wunsch

Electrical and Computer Engineering ETDs

There are at present several conventional techniques and systems to measure the peak amplitude of high-voltage pulses. Three of the prin­cipal techniques are:

1. Potential dividers in conjunction with some type of low-voltage recording system.

2. High-voltage oscilloscopes with low sensitivity.

3. Sphere gaps with predetermined breakover voltages.

Potential dividers of many types have been developed. These include resistive voltage dividers, capacitive voltage dividers, and combination resistive and capacitive dividers. The different designs have usually been developed to eliminate some error in measurement. Different types of resistive windings have been designed to minimize self-inductance. Shields have been designed to reduce …

Effects Of Oxygen Content Of Admitted Gases In Sulfide Flotation, Brian J. Boyle

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Methods Of Studying The Effects Of Frothers, Frank L. Bazzanella

Bachelors Theses and Reports, 1928 - 1970

No abstract provided.

Evaporation And Potential Evapotranspiration In Central Iraq, Ala H. Al-Barrak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The principal objectives of this study were to compare several formulas for estimating pan evaporation and evapotranspiration and to derive new formulas or modify existing formulas that will better fit the data for central Iraq. Computed evaporation was compared with measured evaporation by determining the differences and the ratios. The pan evaporation formulas were also compared by expressing them all in the form
Ev = K C_RC_TC_WC_HC_DTC_SC_M

Three pan evaporation formulas were modified. For the Meyer and Utah formulas, the constants were changed and expressions were derived …

Simplified Approach To The Problem Of Stability Of Soil Slopes Under Horizontal Earthquake And Pore Pressure, Dalim Kumar Majumdar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A problem that has confronted engineers for a great number of years is that of determining the stability of soil slopes. Many factors introduce complications into stability analysis. Most embankments contain heterogeneous soils, often of several types. This and other complications usually necessitate the use of a simplified cross section. At the same time, it is often necessary to adopt simplified average soil characteristics which represent actual characteristics as best as possible. Those steps which bear on the choice of the simplified section and the simplified soil characteristics are always important in stability analysis work. These steps are independent, however, …

Point Flow Measurements In Irrigation Furrows, David Ernest Mortin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A new flow measurement concept is needed to facilitate the study of intake characteristics of the soil under furrow irrigation. Knowledge of the flow rate at various points throughout the furrow length is required but measurement must be made without altering the normal flow regime. Conventional water measuring devices such as weirs, orifices or flumes which require a loss of head in their operation, are usually unsatisfactory because to create a measuring head would alter the normal flow depth upstream thus changing the intake pattern.

The purpose of this study is to develop a simple, reliable method of measuring small …

The Purification, Analysis And Growth Of Single Crystals Of Organic Semiconductors, Melvin Leonard Druin

Theses

The purpose of this investigation was to design and construct a furnace for growing large single crystals of organic compounds by slow crystallization from the melt by the Bridgman technique. The crystals obtained by this furnace will be used in a later investigation of the intrinsic electrical and optical properties of organic semiconductors.

The methods describe have been used width success to produce large single crystals of anthracene and ethyl-p aminobenzoate with diameters of 1/2 inch.

The most promising methods of purification of anthracene, which were chemical synthesis, washing, recrystallization from solvents, sublimation, dimerization, co-distallatian and zone refining have been …

Predicting Current Gain Degradation In Npn Silicon Transistors After Irradiation By High-Energy Neutrons, Jerry A. Hood

Electrical and Computer Engineering ETDs

The damage discussed in this report is permanent and remains after all transient ionization has decayed. The damage which predominantly affects the electrical characteristics of a transistor is the creation of "vacancies" and "interstitials" in the lattice structure. These defects are created when an atom is knocked from its position and leaves a vacancy in the lattice. The atom comes to rest in a position out of the lattice structure and is known as interstitial. These atoms are knocked from their positions by the irradiating neutrons or by an interstitial traveling through the crystal. These defects occur in localized clusters …

Temperature Distribution And Thermal Stresses In Radiation-Cooled Circular Cylinders, William E. Putman Jr.

Mechanical Engineering ETDs

This study involves the determination of the transient temperature distribution and thermal stresses in a solid circular cylinder cooled by thermal radiation. The analytical solutions are presented in dimensionless form. Theoretical results are shown for temperature distribution and thermal stresses in the nondimensional form. Certain of these results are given in the dimensional form for the model cylinder used in this investigation.

The uranium-zirconium prototype element was thought to be undesirable for this investigation. Therefore, similitude was used to select a model which could be used for the experimental work. A solid, cylindrical, epoxy model was constructed, and thermocouples were …

The Design Criteria Of A Phoswich Transducer., Richard L. Crawford

Electrical and Computer Engineering ETDs

This dissertation is an experimental and theoretical treatise on the design criteria of a phoswich transducer. The major emphasis is on the application in a gamma-ray spectrometer. The conversion efficiency, gamma-ray cross sections, response to charged particles, luminescence decay time, spectral response and physical qualities are discussed, in considerable detail, in making the optimum choices for the inorganic crystal and the organic phosphor which will act as the charged particle anticoincident shield. The effect of the thickness of the anticoincident shield on resolution, the percentage of gamma-rays absorbed, the percentage of gamma-rays that are atten­uated in energy and the lower …

Electric Fields From Airborne Vertical And Horizontal Dipoles At Very-Low Frequencies, A. H. Garry Gibson

Electrical and Computer Engineering ETDs

A gap exists in present-day knowledge of the electric fields in the earth which are radiated from elevated antenna structures in the earth-air-ionosphere waveguide. It is the purpose of this paper to present a method of estimating the electric field at the earth-air boundary, caused by elevated antenna structures, and to show the existence of new phenomena that may lead to an improved design of communication systems.

Effect Of Liquid Viscosity On Performance Of Wire Mesh Entrainment Separators, Raymond Paul Vogel

Theses

The knitted wire mesh entrainment separator, commonly referred to as a demister*, is in common use to separate entrained liquid from vapor streams. However, little quantitative information is available concerning the effect of physical properties of the entrained liquid on allowable gas velocities.

Studies were made on two demister styles to determine the effect of liquid viscosity on demister performance, Liquid viscosities from 0.9 to 12 centipoise were investigated using water, glycerine-water mixtures and heavy no. 2 fuel oil as the test liquids. Air was used as the gas medium in all cases.

Regression analysis of the test data indicates …

Generalized Programs For Heat Transfer Analysis., Ceylung Chu

Masters Theses

"This report presents numerical methods for calculating temperature distributions in any physical system in which heat transfer is taking place. The syste.11 may be at either a steadystate condition or a transient condition. The temperature distribution may itself be or primary interest, or it may be used further to calculate the flow or heat or thermal stress.

The system under investigation is divided into a certain number of subdivisions, or so-called "regions". A reference point (node point) will be taken as representative for the region which includes that point. The temperature at the "node point11 is taken to be the …

Experimental Evaluation Of Thermal Stresses On The Outer Surface Of A Thick-Walled Tube., Vinodray T. Patel

Masters Theses

"In this investigation an attempt has been made to measure thermal stresses on the outer surface of a thick- walled tube. The inside surface was heated by steam passing through the tube while the outer surface was cooled by water. Two temperature compensated strain gages were used to measure strains in the tangential and axial directions respectively. The advantage of using this type of strain gage is to avoid the use of a dummy gage to compensate for the temperature effect.

The analytical solution to the problem was derived and the values of thermal stresses were calculated theoretically and compared …

Zirconium Chloride Nuclear Battery, Lonnie J. Shalton

Masters Theses

"An investigation of the neutron absorption characteristics of zirconium chloride was made to verify the reports of Chicago Development Corporation (5810 47th Ave., Riverdale, Md.) that ZrCl Blight be used as a power source for a nuclear battery. The company detected what they believed to be a beta current when the ZrCl was bombarded with neutrons from a slightly enriched uranium source. Investigation using higher powered neutron sources revealed that such a current was highly improbable and the company incorrectly interpeted the phenomena. Reports in the literature also confirmed that an electric current from the ZrCl using a low powered …

A Study Of The Eddy Diffusivity In Turbulent Heat Transfer, Frank Fu-Kun Tao

Doctoral Dissertations

"The purpose of this investigation was to determine the eddy thermal diffusivity values as a function of radial position at various Reynolds numbers for a fluid flowing turbulently in a pipe. The ratios of the eddy thermal diffusivity and the eddy viscosity were also investigated.

A vertical column of copper tube two inches in diameter was constructed which consisted of an entrance section for the development of the velocity profile and a heating section for the development of the temperature distribution. The heating section was jacketed and maintained at a constant wall temperature at about 103 ° F by the …

Lattice Parameters, Thermal Expansion Coefficients, Densities, And Imperfections In Silver And In The Alpha-Phase Of The Silver-Indium System, Samir Moustafa Riad

Doctoral Dissertations

“An investigation of structure insensitive properties (lattice parameters, thermal expansion coefficients, densities, and imperfections) of silver and the α-phase of the silver-indium system was suggested by the desirable uses for silver and its indium alloys.

Both silver and indium used were 99.999 per cent pure. The silver-indium alloys were prepared by melting both metals inside evacuated and sealed fused quartz tubes. The solidified alloys were annealed and then examined by X-ray diffraction for homogeneity.

This experimental work is divided into three main parts:-

I. X-ray diffraction investigation to determine the solid solubility limit of the Ag-In α-phase at 25° C, …

A Study Of Plane And Spherical Compressional Waves In A Voigt Viscoelastic Medium, Gerald B. Rupert

Doctoral Dissertations

"In investigating the behavior of waves traveling through cohesive solids, two assumptions are usually made: that the propagating medium is either elastic or viscoelastic, and that the wave is either planar or spherical in form. For small distances from the source of the disturbance the medium can be considered elastic and the wave spherical rather than planar. The assumption of elasticity allows considerable simplification of the mathematical analysis, and assuming a spherical wave form is an acceptable approximation if the initial disturbance is essentially a point source and the propagating medium is nearly homogeneous. However, for large distances from the …

The Effects Of Granular Size On The Thermal Conductivity Of Sand, Kanubhai M. Patel

Masters Theses

"The thermal conductivity of granular materials can be determined by the Thomas method. This method was used here to determine the effects of granular size on the thermal conductivity of sand. A river sand was secured and screened. The sand retained between the Tyler Standard Screen Scale, mesh 10 and 14, 14 and 28, 28 and 40, 40 and 48, 48 and 60, and below mesh 60, was used for tests.

The thermal conductivity for the above six samples obtained by the author coincide fairly well with published data.

It is reported in the International Critical Tables that the thermal …

A Determination Of The Theoretical Stresses In A Deep Beam., James William Tritz

Masters Theses

"This paper presents an analytical solution of the stress distribution in a deep beam of finite length. The beam being considered is analyzed as one of plane stress. The method employed superimposes two stress functions each of which is a trigonometric series. The first stress function satisfies all boundary conditions except that of zero stress on the vertical faces. The second function is found, so that, when combined with the first function, all boundary conditions are satisfied. The IBM 1620 digital computer is then used to find the stresses for a particular beam. The results of this analysis are then …

The Prediction Of The Thermal Conductivity Of Various Binary Non-Polar Gaseous Mixtures., Chester Foon-Chen Feng

Masters Theses

"A simple method for predicting the thermal conductivity of binary non-polar gaseous mixtures from the force parameters of the pure components and composition was developed. The method is an extension of the application of the combining methods previously derived for viscosity predictions. Altogether, the published thermal conductivities of 683 binary non-polar mixtures at various temperature levels were compared with the corresponding calculated thermal conductivities resulting from the prediction method. The corresponding values predicted from Hirschfelder, Curtiss and Bird's expression were also compared.

Among the 683 binary mixtures, there were 138 di-di, di-poly, and poly-poly mixtures, 241 mono-