Digital Commons Network^™

Aging Of The Dielectric Properties Of Some Perovskite Ceramics, Hector Troche-Maldonado

Masters Theses

"The effect of aging upon the dielectric constant and the dissipation factor were investigated for a number of lead titanate zirconate ceramics of varying composition. The ceramics investigated have a perovskite type structure. The materials chosen all have tetragonal symmetry at room temperature but are close in composition to materials of rhombohedral symmetry.

Empirical relations were determined for each specimen giving the rate of aging of the dielectric constant (K) and loss factor in terms of the frequency (f) and the elapsed time (t). The range of frequency was l kcps to l mcps; the range of elapsed time was …

The Dissolution Of Deformed Magnesium In Sulfuric Acid., William J. Daniels

Masters Theses

"The negative difference effect exhibited by magnesium while anodically dissolving in saline solutions has been attributed in part by Kokoulina and Kabanov to the expulsion of univalent magnesium ions ^{1, 2}. Recent experimenters have discounted the concept of the anodic expulsion of uncommon valency ions and have explained both the positive and negative difference effects observed for magnesium in dilute acids on the basis of anodic polarization, film disruption, and disintegration of the magnesium anode, i.e. "chunk effect"^{3, 4}.

The purpose of this present investigation was to study the difference effect for deformed magnesium in a dilute …

The Indole Acetic Acid Oxidase Of Hygrophorus Conicus., Dilip N. Patel

Masters Theses

"The purpose of this investigation was to determine an assay method for measuring the activity of the indole acetic acid oxidase present in Hygrophorus conicus. This enzyme converts tryptamine or indole acetic acid (IAA) into oxindole acetic acid (OIAA).

An assay method for measuring the activity of the enzyme was developed based on the spectrophotometric measurement of tryptamine, IAA, and OIAA. Several other assay methods were tried. The colorimetric method of Gordon and Weber ^(l4) was found to be useful for a quantitative determination of IAA and was insensitive to OIAA. Paper chromatography proved to be useful as a qualitative …

A New Method For The Evaluation Of Metal Primers., Bhalchandra Dave

Masters Theses

"Corrosion is the destructive attack of metal by chemical or electrochemical reaction with its environment. Rusting is usually the term applied to the corrosion of iron-base alloys with formation of corrosion products consisting largely of hydrous ferric oxides. Non-ferrous metals therefore, corrode but do not rust. ^(l4) More than 40 per cent of the world's production of steel and iron is destroyed by rusting which costs about six billion dollars every year. In 1954 the American Petroleum Industry, Subcommittee on Corrosion, published a preliminary estimate that corrosion was costing 2 the petroleum refining industry between eleven and nineteen cents per …

Forced Convection Heat Transfer Coefficients And Induction Heating, Max Edwin Light

Masters Theses

“The purpose of this study was to design and build an apparatus to experimentally determine the convective heat transfer coefficients for water flowing in a horizontal tube at turbulent flow. Also it was planned to use the apparatus to investigate the spatial dependence of energy deposition by induction heating.

An instrument and measuring techniques were developed that gave reasonable correlations between experimentally determined heat transfer coefficients and values calculated from generally accepted heat transfer relationships developed by other experimenters. Most of the calculated values were within ± 10% of the experimental values for a wide range of flow rates.

It …

The Effect Of Cation Size Of Xanthate Collectors In Sulphide Flotation., R. W. Bourne

Masters Theses

"Batch flotation tests on Utah Copper ore were used to show the effect of collector cation size.

The results obtained were:

(1) Recovery of copper in the concentrate decreases with increase in the size of the collector cation.

(2) Increased recovery with ethyl over that for amyl with a given cation.

(3) No beneficial recovery with sulphur enriched xanthates.

Statistical techniques were used to ascertain if significant differences in results were present"--Abstract, p. i

The Effect Of Moisture Content On The Action Of Sea Coal In Molding Sands., Robert J. Endres

Masters Theses

"An assumption was made that an increase in moisture content in the sand would result in an increase in the amount of volatile matter retained in a sand, clay, water, and sea coal mixture which had been subjected to the heat of molten iron. Because of a lack of positive evidence to support this assumption, it was concluded that the volatile matter retained within the sample is independent of the moisture content.

It was also shown that the volatile products do not travel back through the sand, away from the mold-metal interface. Rather, the volatiles escape from the sand and …

The Removal Of Residual Organic Materials From Sewage Plant Effluents Using Continuous Foam Flotation., Ajab S. Malik

Masters Theses

"This investigation was conducted to determine the feasibility of using a continuous foam flotation process for the removal of soluble organic materials from sewage treatment plant effluents. All effluents contained alkyl benzene sulfonates (ABS), derived from synthetic detergents. The studies were conducted on a laboratory scale. The reduction in the chemical oxygen demand was used as a measure of the effectiveness of the removal of the organic materials. In addition, ABS determinations were employed to study the fate of the detergent.

A flotation cell, equipped with the means of controlling the air and liquid flow rates, was used. Air flow …

The Resolution Of Two Known Signals In White Gaussian Noise., Peter Cheng-Fang Wang

Masters Theses

"The problem of resolving two signals F1(t) and F2(t) in white Gaussian noise n(t) is treated here as a problem in statistical decision theory. We assume a situation in which one of two similar signals is present and an observer is asked to make a decision concerning which of the signals is present with a tolerable probability of error. The observer is allowed to use the best system which he can design for this particular purpose. Of course, this observation will be disturbed by noise and therefore, the observer is led to ambiguous selections. It is apparent that the optimum …

Optimum Zero-Memory Nonlinear Filter, Benjamin Shaw-Hu Wang

Masters Theses

“The purpose of this report is to review the basic work described by Zadeh insofar as systems of class N₁ are concerned and to apply his general results to a specific problem in which a non-linear filter is mandatory simply because the linear filter is essentially ineffective. The ineffectiveness stems from the fact that the autocorrelation function of the signal plus the noise has essentially the same variational character as the signal alone. Therefore, the transfer function of the linear filter turns out to be simply a constant. Thus, the output of the linear filter is just an attenuated …

The Plastic Behavior Of Beams With Butt Welded Connections., Paul George Hayes

Masters Theses

"The purpose of this study is to determine the length of butt welds required to develop the full plastic section modulus of a 6 WF 20 rolled section of A-36 steel. The members were electric arc welded with LR 6070 electrodes. Two-point loading was used to develop a zone of pure moment with zero shear where these members were joined.

At the cross-section to be welded, all the flange edges were prepared to receive a single-vee butt weld and the webs were prepared for a double-vee butt weld. In all cases the full length of the flange was welded. However, …

A Laboratory Study Of The Effect Of Wettability Of Residual Oil Saturation In Artificial Cores., Socrates Nicholas Potamianos

Masters Theses

"In the past much emphasis has been placed on various studies of reservoir rock and fluid surface properties and their relation to the different oil recovery processes. Several laboratory methods (1, 2, 3) ^l/have been used by different investigators to obtain a more fundamental understanding of the many factors which have an influence on the oil recovery from reservoir rocks"--Introduction, p. 1

A Study Of The Phase Behavior Of Carbon Dioxide-Methane-Normal Decane Systems, Raja Audi Mansoor

Masters Theses

“The effect of carbon dioxide concentration, on solubility has been studied for several carbon dioxide-methane-n-decane systems. Experimental results were obtained using differential vaporization tests. Computational results were obtained using equilibrium constants.

The relation between solubility, bubble point pressure and solution carbon dioxide is presented. A ternary diagram showing the bubble point pressure behavior as a function of system composition is also presented”--Abstract, page ii.

Design, Construction And Characterization Of A 10-Liter Batch Pilot Plant Fermentor., Sylvester Ogden

Masters Theses

"A 10-liter batch type pilot plant fermentor has been designed and constructed. The design incorporated most of the desirable features of previous designs reported in the literature.

The stainless steel fermentor has a multi-speed agitator and aeration rates as high as 15 cubic feet per hour. Temperature indicating, temperature controlling, pH measuring, and automatic foam controlling systems are included in the design.

Sulfite oxidation rates have been determined for the unit at 15 operating conditions. A maximum sulfite oxidation rate of 1060 millimoles of oxygen per liter per hour has been obtained.

Fermentation using a Torulopsis utilis yeast culture has …

The Imperfect Structure Of Ti-, Zr-, And Hf- Nitrides Containing An Excess Of Nitrogen., Chester A. Faunce

Masters Theses

"Chemical analyses were made on all three nitrides using oxidation, Kjeldahl, dissolution and gas evolution techniques, and the chemical formulae were calculated. They are as follows: Ti_0•931^N, Zr_0•970^N, and Hf_0•792^N.

The lattice constant of all the nitride samples was determined at 25°C. The Ti_0•931^N sample obtained from Union Carbide Company had a lattice parameter of 4.23986± 0.00007A⁰, while the sample from W. Germany, Ti_1.0^N in the as received condition had a lattice parameter of 4.24027 t 0.00003A⁰• A second lattice parameter determination was …

The Anodic Dissolution Of Cadmium In Aqueous Solution, Yun-Chung Sun

Masters Theses

"The increasing importance of prevention of corrosion in industry has stimulated extensive studies on the fundamental behavior of metals in corrosive media.

The basic mechanism of the anodic dissolution of metals such as cadmium, magnesium, and zinc in salt solutions is not completely known. Several mechanisms have been proposed by different investigators, but evidence is still lacking to draw unquestionable conclusions to explain the discrepancies which often arise between coulometric data and weight loss of metal electrodes in certain salt solutions.

The purpose of this investigation was to obtain experimental data for anodic dissolution of cadmium in various electrolytes and …

Sonic Flow Meter., Daniel E. Wilson

Masters Theses

"The purpose of this thesis was to construct a device to measure the velocity of air employing sound waves. The principle of operation of the device is that the time interval required for the sound wave to travel between two points in the duct is a function of the fluid velocity. This time interval was measured both with the air flowing and with the air stationary. An equation was derived such that the mean velocity of the flowing air could be calculated by knowing the two-time intervals.

The mean velocity determined by this device was compared to the mean velocity …

Time Optimum Switching Zones In Multiple-Valued Control Systems, Jack Leroy Crawford

Masters Theses

"Present control system theory provides the criteria necessary to bring a second-order single-valued system to rest in a minimum time after a step input. The bang-bang type controller has been developed to obtain this optimum response.

However, existing theory fails to provide the necessary information to obtain the optimum response from a second-order rotational system when multiple values of angular position are allowed. This thesis extends the control theory to include these multiple-valued systems by showing the existence of what are called optimum switching zones. These zones predict which of the infinite number of switching curves in a multiple-valued system …

The Design, Construction, And Evaluation Of A Vortex Stabilized Plasma Generator, Ronald Ray Williams

Masters Theses

“This report presents the design, construction, and evaluation of a vortex stabilized arc plasma generation facility operating on argon.

The facility consisted of five basic systems; the plasma genera- tor, the electrical power system, the argon flow system, the cooling system, and instrumentation.

The facility was designed to meet four general requirements; stable arc operation, low electrode deterioration, low cost of construction, and provisions for determination of the operating characteristics and thermal properties of the plasma.

Experimental results obtained in the laboratory agreed well with the design conditions. The rate of energy dissipated in the electric arc varied from 7. …

The Design, Construction, And Calibration Of An Angular Accelerameter., Walter Earl Palm

Masters Theses

"The purpose of this work was to design, construct, and calibrate an angular accelerometer for continuous operation. The design uses four symmetrically placed springs connecting a ring and hub. Strain gages are mounted on the springs in a Wheatstone bridge arrangement. When the entire unit is subjected to an angular acceleration, the ring deflects causing an output voltage. This voltage is proportional to the deflection which is shown to be a function of the angular acceleration. The accelerometer was constructed to operate at frequencies up to 120 cps. The calibration was accomplished by using a simple harmonic motion input"-- Abstract, …

A Preliminary Study Of The Controlled Crystallization Of A Bottle Glass., Narayan M. Sedalia

Masters Theses

The effect of addition of Ti0₂ as a nucleating agent was studied with a bottle glass composition of 74 weight percent Si0₂, l percent Al₂O₃, 5.4 percent Cao, 3.7 percent MgO, 15. 3 percent Na₂O, and 0.6 percent K₂O as a base or original composition. The addition of titanium dioxide ii varied from 3 to 20 weight percent. The composition of this bottle glass was changed by increasing the following ingredients and keeping the other ingredients in the same ratios:

1. Increased 5 weight percent of Al₂O …

Compensator Design For Unity Feedback Systems Using An Analytical Method, Chang-Yu Wu

Masters Theses

“In control systems engineering it is frequently necessary to compensate a fixed plant whose transfer function cannot be changed. Usually the characteristics of the resulting system are established in terms of steady-state and transient performance specifications. Generally it is necessary to insert a compensator which insures stability as well as satisfies the specifications.

In this thesis an analytical method is developed to determine the transfer function of the compensator in order to satisfy the following set of specifications. The fixed system is assumed to contain one non-linearity, saturation. The input to the saturable device is constrained in a statistical …

Compaction Characteristics Of Fine Grained Soils., Lewis Clyburn Sowell

Masters Theses

"The existing theories of compaction of soi Is are reviewed. The effect of varying the compactive effort on dry density, optimum moisture content, and compressive strength for three fine grained soils is investigated. These samples consist of si I ty clay (CL), plastic clay (CH), and loess (ML). The test results indicate that compactive effort has an important effect on the shape of the moisture density curve and that a potential for over compaction increases with a higher plastic index and c l ay content. At water contents above the Standard AASHO optimum value, the compressive strength is not appreciably …

Microscopic Observations On Etched Surfaces Of Zinc Single Crystals And On Anodic Disintegration., Yun Wang

Masters Theses

"The technique used to grow single zinc crystals was based on the Bridgman method. Zinc-gold, zinc-aluminum, and zinc-magnesium alloys were prepared and their single crystals were grown. Four crystallographic planes of the single zinc crystals were used for both chemical and anodic etching. The zinc alloys were etched more easily by acids than the purest (99.999%) zinc. The etching patterns changed for the different crystallographic planes of the single zinc crystals.

The appearance of particles during anodic dissolution of the single zinc crystals depended on time, acid concentration and current density. The partial disintegration of single zinc crystals is promoted …

The Characteristics Of Radial Strain Propagation Induced By Explosive Impact In Jefferson City Dolomite., Choon K. Quan

Masters Theses

"Blasting effects depend largely on peak radial strains propagated in rock media by explosive impact. To improve blasting design and control of secondary effects (e.g., structural fatigue), an equation for peak radial strain propagation induced by explosions was developed as follows: Emax = K e^-αr /r

An instrumental technique was designed to test the validity of the equation in the Jefferson City dolomite. Results showed ii that for 1-lb charges of 60% ammonia-gelatin explosive, peak strains, at any distance r, were reduced in amplitude in accordance with an exponential decay function of the type Emax = 281 e^{-0.026r …}

Theoretical Investigation Of Steam Jet Cleaning, Jaswant T. Lotwala

Masters Theses

"Steam cleaning methods are used by industries to remove mass of dirt and grease deposits from machine parts and other surfaces. It is necessary to know the rate at which this mass can be removed from a surface. The present investigation was made to determine this rate of mass removal. The mass transfer rate is influenced by two phenomena; namely, heat transfer and momentum transfer. Both of these were discussed and the results obtained from the analysis were used in determining the total mass transfer rate. The effects of various parameters, such as density and velocity of the cleaning fluid, …

High Order Bang Bang Control System., Shing-Chou Pi

Masters Theses

"The problem undertaken in this thesis is to find a representation of a nonlinear controller to minimize the response time of a limited input plant whose transfer function has N negative real poles. The extension of the phase-space method to automatic control systems described by high-order differential equations with a general high-order input is considered.

The design utilizes a maximum effort controller whose switching time is determined by the concept of switching hypersurfaces of the system in N-dimensional phase space and the concept of a distance function, which is & geometric length between the initial state point and the switching …

Investigations Of The Feasibility Of Transporting Ore In Open-Flumes., Kirtikant R. Sheth

Masters Theses

"Considerable effort has been expended and many data are published on developing the technologies of pipeline transportation and hydraulic hoisting. However, comparatively little information is available on the techniques of hydraulic mining, and nearly none ii is reported on conveying slurries in open flumes. For this reason, the author chose to investigate some of the parameters that influence open-flume transport.

It was found that Durand has assembled the findings of several investigators into a simple mathematical expression which is accepted as a standard for designing slurry pipelines. ·Further investigation by the writer revealed that Durand's formula, with only minor modification, …

Construction And Test Of Equipment For Use In Ultrasonic Pulse Echo Studies., Charles Joseph Reinheimer

Masters Theses

"An ultrasonic pulse generator was constructed with a variable pulse width ranging from 4 microseconds to 10 milliseconds and a repetition period varying from 15 milliseconds to 5 seconds. The oscillator had an almost continuous range from 500 kilocycles to 18 megacycles per second.

Its applicability in studies of internal friction of metals was demonstrated with a single crystal aluminum sample"-- Abstract, p. vi

The Effect Of An Induction Field On Transducers., Ratilal S. Patel

Masters Theses

"This report presents the results of an experimental investigation on the effect of an induction field on transducer output. Various types of transducers; strain gages, thermocouples, and thermistors, were used. The changes in the output of these transducers were measured for various induction field conditions.

Measurements must often be made where strong electrical fields are present. Strain gages are used to measure the stresses in electrical machinery. Thermocouples and thermistors used for measuring the temperature of materials undergoing heat treatment with an induction heater are also subjected to an induction field.

The general experimental procedure was the same throughout the …