Engineering Commons^™

Physico-Chemical Principles Of Sixteenth Century Metallurgy, Robert E. Johnson

Bachelors Theses and Reports, 1928 - 1970

Following a review of sixteenth century metallurgical literature and a discussion of Gibbs free energy, this thesis discusses thermodynamic considerations of galena (PbS) reduction by iron from a lead assay of this period. The importance of fluxes in this assay is emphasized. The discussion covers both equilibrium and non-equilibrium conditions at 1100 degrees Celsius. Possible substitutes for iron are also covered.

Information from twenty-one small controlled lead assays is correlated with the thermodynamic discussion to determine the purpose of each constituent in the assay.

Complementary Transistor Memory Circuit And Logic Applications, Lee M. Bossart

Electrical and Computer Engineering ETDs

No abstract provided.

The Beneficiation Of Titaniferous-Magnetite Sands, Ronald Lloyd Nordwick

Bachelors Theses and Reports, 1928 - 1970

The purpose of this investigation of beneficiation methods is to develop and study possible economic methods for recovering an iron-titanium concentrate of sufficient purity to meet metallurgical requirements for subsequent direct reduction to pig iron and a high titanium slag.

A Study Of Sprinkler Uniformity Evaluation Methods, Baha Dabbous

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The use of water in homes, on farms, by factories, and for recreational purposes has been increasing rapidly. Water use has doubled in the last three decades. By 1980, water use is expected to be double the current use. In arid and semi-arid regions, the practice of successful profit-yielding agriculture often depends on irrigation. Irrigation is, in turn, dependent upon a water supply which is limited. The highest possible efficiency should be maintained if maximum utilization of the available water resources for irrigation is desired. Sprinkler irrigation allows, among other things, high water application efficiencies with good distribution uniformities.

The Aerodynamic Drag Of Spheres, Leon Rouzelle Scott

Theses and Dissertations

A literature survey was conducted to determine the factors which affect aerodynamic drag of spheres. Graphs are presented which show the effect of each variable where such information was available. Equipment was designed and built for the purpose of studying the effects of acceleration on the aerodynamic drag of spheres. Special emphasis was placed on the measurement and control of each of the other variables which can affect the drag. Tests were conducted using large spheres in air and water to show that the method presented can produce a valid determination of the drag coefficients. The numerical values of the …

Stress-Corrosion Cracking Of Brass, Paul A. Fossey

Bachelors Theses and Reports, 1928 - 1970

the mechanism of stress-corrosion cracking of brass has been sought for many years. Investigators have proposed many mechanisms, but each of these mechanisms has always had several drawbacks. This paper presents an account of experimental work done in the laboratory on this subject and compares it to the work of previous investigations. It evaluates the mechanisms presented by investigators and shows the failures of these mechanisms. A theory of Nitrogen Embrittlement is presented and an evaluation of this theory with experimental work follows.

Experimental Arc Furnace Smelting Of Titaniferous Iron Sands From The Northern Oregon Coast, Allan P. Herring

Bachelors Theses and Reports, 1928 - 1970

This investigation is an attempt to experimentally smelt titaniferous iron sands from the Northern Oregon Coast in a laboratory arc furnace.

The Effect Of Ph Upon Chelation Reactions In Montmorillonite Clays, Joseph Michael Keane

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to investigate several chelation reactions and determine the effect of variable pH upon these reactions.

An Investigation Of The Sintering Of Iron-Wire Compacts, George L. Vivian

Bachelors Theses and Reports, 1928 - 1970

A study of the sintering of iron has been made by observing the rate of bonding of iron wires wound on iron spools. The specimens were sintered at a constant temperature of 850c in vacuum furnaces capable of producing pressures of 10-5 to 10-4 mm of mercury, and the growth of the bond between wires was observed as a function of time.

It has been concluded that the volume-diffusion mechanism is strongly operating in the sintering of iron at 850c, but in an evacuated system, the evaporation-condensation mechanism also contributes to the sintering process.

An Approach To Azimuth Angle Refraction Corrections, Wallis R. Cramond

Electrical and Computer Engineering ETDs

In the past, analyses of tropospheric reactions of electromagnetic waves propagating in the atmosphere have been based on spherically symmetric medium. However, this applies only to ray bending in a vertical plane (elevation angles). Numerous methods have been developed to correct for elevation angle errors. In 1961, the presentation of a new method for use in a nonsymmetric atmosphere revived interest in horizontal (azimuth angle) bending. In order to use this method to test significance of azimuth angle errors, the spacial distribution of index of refraction must be known.

The primary objective of this paper is to propose a model …

A Theory Of Self-Evaluating Discrete Communication Systems, Samuel D. Sterns

Electrical and Computer Engineering ETDs

No abstract provided.

Radar Back-Scatter Theories For Near-Vertical Incidence And Their Application To An Estimate Of The Lunar Surface Roughness, Harbhajan S. Hayre

Electrical and Computer Engineering ETDs

This work, after the critical examination of the theoretical background on back-scattering from rough surfaces, offers a new approach to its theory. Various back-scatter theories, as well as the statistical models of terrain and moon assumed therein, are critically reviewed and correlated. A new approach which uses a simple statistical model is then presented for the description of scattering of electromagnetic waves from a rough surface. The statistics of a rough surface are discussed in terms of certain parameters which can be easily associated the surface features, and a new expression for the back-scattering radar cross section per unit area …

Plastic Models For The Study Of Thermal Stresses, Carl W. Theisen

Mechanical Engineering ETDs

The purpose of this thesis was to determine and evaluate an experimental method for accurately measuring thermal stresses in structural shapes subjected to large transient thermal gradients, without introducing the problems of high temperature instrumentation, or expensive and elaborate test facilities. Most experimental methods consist of mounting high temperature strain gages on the prototype or model of the metal structure to be evaluated, thermal shocking the structure and then recording the accompanying strains. This method is used quite extensively in the aircraft field, and in others, where the effects of thermal stresses must be considered. However, problems are encountered when …

A System For Recording Electromagnetic Atmospheric Noise In 30-50 Cps Region, James F. White

Electrical and Computer Engineering ETDs

The electromagnetic noise spectrum extends from below 1 cps to above 3,000 mcs. Within this spectrum many phenomena of atmospheric noise have been observed. Those atmospherics which occur in the audio frequency region of the spectrum have been given not only descriptive but also subjective names by many different investigators. As a result, it is often difficult to determine from the literature what aspect of the noise phenomenon is being considered. In addition, references to low frequencies involved in certain experiments are vague. A brief history of atmospherics research is presented here in order to explain the terminology, to show …

A Study Of Gamma-Ray Photoconductivity In Organic Dielectric Materials, Stanley E. Harrison

Electrical and Computer Engineering ETDs

The gamma-ray photoconductivities of polyethylene, polystyrene, polyvinylchloride, polypropylene, Teflon, Nylon, Kel-F, and three thermosetting resins denoted as Epoxy 1478-1, 1478-3, and 1478-22 have been measured. The measurements were made at steady-state gamma-ray intensities ranging from 1.0rad(H₂O)/min to 3.0 x 10⁵ rads(H₂o)/min and at controlled temperatures ranging from 90 degrees Fahrenheit to 140 degrees Fahrenheit. Conductivity changes resulting from the steady-state gamma-ray exposures were measured continuously throughout the exposure and after the exposure. The exposure period was of sufficient duration to allow all samples to achieve an equilibrium conductivity value.

The Development Of A Static Pressure Probe For The Interaction Region Of Shock Waves And Boundary Layers, John Rode

Mechanical Engineering ETDs

The purpose of this investigation was to develop a static pressure probe for measuring static pressures in the region of interaction of a shock wave and a boundary layer. Requirements of such a probe are: small size to permit measurement of pressure variations within the thin boundary layer, pressure coefficient close to unity to permit precise static pressure measurements in regions of unknown and varying velocity and proper response to large pressure gradients.

An Evaluation Of Concrete Making Properties Of Scoria Lightweight Aggregate Based On Compressive Strength, Khurshid Ahmad Chaudhry

Civil Engineering ETDs

Compressive strength of scoria-aggregate concrete was examined by introducing controlled variables into the mix proportions. A mix design method for accurate mix design was formulated and was analyzed for consistency and feasibility.

A Qualitative Study On An Exploding Wire Fuse, W.D. Lacoss

Electrical and Computer Engineering ETDs

This study was undertaken in an effort to develop basic concepts of normal operating fuse criteria that will apply to capacitor energy storage systems. To develop ideas germane to normal fuse operating limits, it was necessary to consider certain principles that preceded this development: (1) A review had to be made of some of the experimental work on the exploding wire phenomenon to indicate a possible application as a fuse; (2) A typical circuit requiring such a fuse had to be described schematically and analyzed to show the dependency between the circuit parameters and the necessary conditions for obtaining fusing …

A Tunnel Diode Parametric Down Converter, Leland Lovell Long

Masters Theses

"The problem, as presented, is to derive analytical expressions for the conversion gain, bandwidth, and noise figure of a self excited tunnel diode converter and to verify, if possible, the validity of these express- ions by building such a converter. These analytical results are presented and discussed. The converter circuit is shown along with the resulting intermediate frequency output. Gain and bandwidth measurements are also given. It is concluded that the self excited converter could very definitely be of value as a low noise pre-amplifying device in the ultra-high frequency and microwave frequency ranges"--Abstract, page ii.

A Comparison Of The Load Carrying Characteristics Of Hydrostatic Thrust Bearing Using Monatomic, Diatomic, And Triatomic Gases, Joseph C. Pigott

Masters Theses

"The purpose of this investigation is to compare the load carrying characteristics of gases with different ratios of specific heat. The design, construction, and operation of an apparatus for testing and comparing the load carrying characteristics of gases are described. Several monatomic, diatomic, and triatomic gases were tested and the results evaluated and compared. The data are tabulated and displayed in a series of curves.

It was found that the monatomic gases exhibit a greater clearance for a given load and a greater total load carrying capacity than the diatomic gases which in turn have a greater clearance and total …

Model Analysis By The Moiré Method, David D. Kick

Masters Theses

"This study presents the use of Moiré fringes for model analysis of deflections and strains. Deflection of a beam, strain in a disk, and an Influence diagram for a frame are presented as examples of uses of the Moiré method. The necessary equations for the determination of strain using the Moiré method are also derived and presented in this work"--Abstract, page v.

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 …

Circular Arch Analysis, Aylmer Pao-Sheng Cheng

Masters Theses

"This work presents an analysis of a two-hinged circular arch by both the elastic theory and the deflection theory. The basic assumption made in this analysis was that the moment of inertia of the arch rib and the normal force vary as the secant of the angle with respect to the crown. The increase of maximum moment as found by the deflection theory was in the range of 30%"--Abstract, page 2.

A Survey Of The Influence Of Selected Sulfides On The Thermal Decomposition Rate Of Zinc Sulfate, L. G. Twidwell

Masters Theses

"The influence which ZnS, CdS, Cu₂S, PbS, and FeS has on the thermal decomposition rate of ZnSO₄ was studied by measuring the SO₂ gas evolved per unit of time for various ZnSO₄-MeS mixtures at 600°C, and analyzing the solid phases by means of X-ray diffraction patterns.

The SO₂ gas evolved upon heating the pellets was analyzed as a function of time by absorbing the gas in a solution of distilled water, H₂O₂, and NaOH, and measuring the time required for the SO₂ to neutralize the NaOH. The gas …

Analysis Of Flat Plates By Reaction Distribution Method, David D. W. Yang

Masters Theses

"This study was made to analyze rectangular flat plates by the method of Reaction Distribution and to compare results obtained by this method with that of other methods. The basic approach is to divide the plate into an equivalent grid system and introduce temporary supports at the intersecting joints. The results from this study shows that the Reaction Distribution method is useful in a qualitative analysis of the behavior in a plate but is less satisfactory in obtaining reliable quantitative results"--Abstract, page 2.

A Study Of Composite Beams Made To Find An Approximate Relationship Between The Top And Bottom Flange Steel Ratio, Murli U. Hasrajani

Masters Theses

"At present in building construction the use of the composite beams is not very common. The use of the concrete beams is seen in almost all construction. By using composite beams in building construction more durability and savings in cost could be achieved. This paper shows an approximate design procedure which could be followed without running a number of trials with different sections to arrive at the required one. The ratio of top flange steel to the bottom flange steel can be determined if one knows the loads, span and the depth of the beam required"--Abstract, page i.

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 …

Thermal Conductometer For Liquids, Yuan-Kai Chang

Masters Theses

"The published data pertaining to the thermal conductivity of liquids are of such a character that it is very difficult to determine from them the correct value, or the temperature coefficient for any liquid.

Most of the published values of thermal conductivity for liquids are evaluated at one particular temperature. It is the purpose of this investigation to design, construct and calibrate a thermal conductometer for liquids over a temperature range of 30°F to 200°F.

Since water and glycerol were the only liquids found by this investigator with published data on their conductivities as a function of temperature, they were …

A Study Of A Second-Order Predictive Control System, Tarkeshwar Singh

Masters Theses

"The purpose of this thesis is the study of a predictive control system by simulating it on an analog computer. Logic criteria for step reference inputs are derived by the phase- plane technique, and tie corresponding logic network designed to bring the error and error rate of the controlled system toward zero in the least possible time.

The responses of the predictive control system for step, ramp, sinusoidal and exponential reference inputs are investigated with primary emphasis placed on the rise time and overshoot for several values of step inputs of the reference.

Finally, recommendations are made for further investigations …

Experimental Evaluation Of Thermal Strains And Stresses, T. F. Lehnhoff

Masters Theses

"This investigation is the study of a method for the experimental measurement of thermal strains. Using four electric strain gages (two of one type and two of another) the method will yield the normal and shear strains as well as the temperature change in any biaxial stress field. The gage types must be chosen for the range of temperature in which it is desired to measure the thermal stresses. The method described eliminates the need for extra resistors, thermocouples, unrestrained dummy gages at the same temperature as the active gages, special alloy gages for each type of metal and special …