Engineering Commons^™

The Dissolution Of Magnesium In Strong Acids And Neutral Solutions, Cheng-Ken Chi

Masters Theses

"The increasing demand for magnesium and magnesium- base alloys in the manufacture of aircraft has stimulated a great amount of research into the corrosion characteristics of these materials. The result of such research has been the development of suitable magnesium alloys and protective coatings to retard corrosion.

The basic mechanism of the anodic dissolution of metals such as magnesium, zinc, and cadmium in salt solutions is not completely known. Several schools of investigators have proposed different and opposing theories to explain the discrepancies which often arise between coulometer data and the weight loss of metal electrodes in certain salt solutions. …

Internal Friction Of Mixed-Alkali Silicate Glasses, James E. Shelby

Doctoral Dissertations

"The mixed alkali effect in silicate glasses was examined from internal friction measurements made over the temperature range from -190 to 500⁰C and at a frequency of 0.4 Hz. Supplemental measurements of the activation energy for the different internal friction peaks, dynamic shear modulus, density, and index of refraction were also made. All measurements were confined to silicate glasses containing mixtures of Li-Na, Li-K, Li-Rb, Li-Cs, Na-K, Na-Rb, Na-Cs, and K-Rb. Rötger's interpretation of the internal friction of mixed-alkali silicate glasses is shown to be incorrect. A previously unreported internal friction peak was observed whenever two different alkali oxides were …

The Microbial Hydrolysis Of Cellulose And Some Factors Affecting The Production Of Cellulase In A Submerged Culture Of Alternaria Sp, Robert Murray Logan

Doctoral Dissertations

"A mile hydrolyzing procedure was utilized to degrade oak sawdust. Its capability of producing a suitable fermentatation [sic] medium was studied. In the interest of solubilizing, enzymatically, the carbohydrate portion of oak sawdust, an investigation was conducted in which various microorganisms were examined for their ability to utilize different forms of cellulose for their growth and to produce cellulose decomposing enzymes. The microorganisms included a myxobacterium, several fungi, and a wood-rotting basidiomycete. The fungi included two highly cellulolytic organisms, Myrothecium verrucaria and Trichoderma viride. The myxobacterium used was Sorangium cellulosum and the basidiomycete was Pleurotus ostreatus. The principla substrates employed …

Construction Of A Capillary Viscometer And The Study Of Non-Newtonian Liquids, Hsun Kuang Yang

Masters Theses

"A capillary tube viscometer was built for the purpose of investigating the fluid properties of non-Newtonian aqueous CMC and Carbopol solutions. The viscometer was tested with Newtonian liquids (glycerine, water and two different oils) having known viscosities to insure that the viscometer was operating correctly. The shear stress-shear rate data obtained for different concentrations of CMC and Carbopol solutions were correlated using the simple power law model. The power law constants were only slightly affected by saturating the solution with iodine and carbon tetrachloride. Aging had very little effect on the viscosities of the CMC solutions but had a considerable …

The Effect Of Varying Sea Coal Fineness On Sea Coal Activity In Molding Sands, Laurence A. Cooley

Masters Theses

"An experiment was conducted in an attempt to establish a relation between sea coal activity in a facing sand and the particle size of the sea coal added to the sand. It was felt that if a sufficient difference in distribution of volatiles was detected, a correlation between particle size and activity of the sea coal within the test specimens might be established. The lack of positive evidence to support such a relationship is indicative that a variation in particle size does not promote volatile re-deposition within the range of particle sizes investigated for the particular weight per cent of …

A Study Of The Structural Rearrangements Accompanying Room Temperature Recovery Of High Purity Aluminum, Carlos Manuel Lago

Masters Theses

"X-ray methods (Laue back reflection and transmission) and etch pit studies were used in order to follow structural changes in the deformed metallic lattice during room temperature recovery. The accumulative evidence indicates that the deformed lattice undergoes subboundary movements and regrouping of fragments within a few days after stressing. On the basis of a superficial investigation, it was found that fast neutron bombardment increases the rate of room temperature recovery. Through the use of a new etchant, a finer substructure was revealed within the Lacombe subgrain. Glide strain values were determined for the series investigated, and a new approach was …

Anodic Dissolution And Disintegration Of Tin And Valency Of The Tin Ions Going Into Solution, Mrityunjoy Dutta

Masters Theses

"The increased demand for protective coatings on metals and for non-corrosive alloys has stimulated extensive research on the fundamental behavior of metals in corrosive media. One of the problems still unsolved is the nature of the mechanism of the anodic dissolution of metals like beryllium, zinc, magnesium, cadmium, tin, aluminum, iron in aqueous salt solutions. It has been reported in the literature that these metals show discrepancies which often arise between coulometric data and the weight loss of metal electrodes in various media. Several investigators have proposed different and opposing theories to explain the above deviation. The purpose of the …

A Study Of Sulfide Inclusions In Medium Carbon Steels, Shane Shiang Yen

Masters Theses

"Sulfur is a very important component in steel. Usually is it present as an impurity in commercial steels. In these materials the sulfur content is 0.05 percent maximum but may be higher or lower than this in some steels...It is generally believed that sulfur has a deleterious effect on the mechanical properties of steels. Originally this investigation was to deal with this aspect of sulfur in steels but the work did not progress to this stage. An effort was made to vary the nature of the sulfides in several experimental heats of steel by controlling their composition. Variation in the …

The Eccentric Orifice As A Flow Measuring Device In Small Diameter Pipes, James E. Casale

Masters Theses

"This thesis reports and evaluates the use of an eccentrically placed orifice as a flow measuring device in small pipe sizes. The orifice is placed in a concentric location and moved to increasingly eccentric locations until full eccentricity is reached. At full eccentricity the circumference of the orifice is tangent to the circumference of the pipe. The effects of increasing eccentricity are evaluated for four orifices...Flow coefficients for the orifices in different locations are plotted against Reynolds numbers. The eccentric orifice is a reliable, accurate flow measuring device for metering or controlling the flow of fluids. Design criteria can be …

Active Band-Pass Filters Using Twin-Tee Networks, Terry B. Watson

Masters Theses

"The primary objective of this thesis was the design and construction of a set of filters to determine the spectral energy density of random signal data in the spectrum from 10 cps to 20 kcps. The statement of the problem placed rather exacting conditions on the cost and performance of the equipment, and these conditions were met to the extent detailed in the following pages. A secondary objective was the investigation of techniques to improve the performance of band-pass active filters using resistive-capacitive feedback networks. This objective was not achieved to the author's satisfaction, although several promising ideas were discovered"--Abstract, …

A Study Of The Effect Of Surface Beveling On Silicon Rectifiers, Gary L. Voorhis

Masters Theses

"The problem in this thesis is to experimentally obtain voltage vs distance data for different angles of bevel, to determine the optimum bevel angle on the basis of minimum surface electric field, and also to determine the location of the maximum surface electric field with respect to the p-n junction. Experimental equipment is constructed and results are graphically illustrated. It is concluded that in general the maximum surface electric field decreased as the bevel angle decreased, that neglecting practical considerations the optimum bevel angle was 3⁰, and that the maximum surface electric field occurred near, but not at the p-n …

Thermal Degradation Of Poly (Methyl Methacrylate) In Solution In Various Solvents, Ya-Chih Chen

Masters Theses

"A study has been made of the thermal degradation of poly (methyl methacrylate) of different molecular weights in toluene, ethyl acetate and chloroform. Four poly (methyl methacrylate) samples having molecular weights of 2,210,000, 733,000, 320,000, and 43,00, respectively were studied in this investigation. The results indicated that the polymer having a molecular weight of 2,210,000 undergoes degradation while the low molecular weight polymers having molecular weights of 733,000, 320,000, 43,000 undergo reverse polymerization"--Abstract, page [ii].

Finite Difference Solution For Triangular Plates, Hao-Yang Huang

Masters Theses

"In this thesis the finite difference method is used to solve triangular plates with uniformly distributed transverse load. As a matter of convenience triangular coordinates are used. The supporting conditions as well as the shape of plate are varied. All calculations are performed by digital computer. The patterns of differential operators in triangular coordinates, the deflections of plates, and the moment distributions are shown and discussed. The results obtained for some special cases are compared with published solutions"--Abstract, page i.

The Effect Of Epoxy Resins On The Plasticity Index Of An A-6 Soil, A. R. Van Steenbergen

Masters Theses

"This thesis reports the results of an investigation of the variation in plasticity of a clayey soil after treatment with small quantities of epoxy resin and curing agent or with curing agent alone. The series of samples tested consisted of an A-6 soil obtained from the vicinity of Rolla, Missouri, combined with: 1. 0-3% of triethylenetetramine hereafter referred to as TETA. 2. 0-3% of diethylenetriamine hereafter referred to as DETA. 3. 0-3% of Araldite 6010 resin cured with TETA. The TETA content was varied form 20% to 100% of the resin by weight. 4. 0-3% Araldite 6010 resin cured with …

Analysis Of Continuous Folded Plate Roofs, Yung-Ping Wang

Masters Theses

"This work presents an analysis of continuous folded plate roofs considering the effects of relative joint displacements. For this analysis the normal modes of the lateral beam vibration were used as the form of the deflection curve and the loading was sinusoidal. By using symmetry and anti-symmetry, a possible method of analyzing prismatic folded plate roofs comprising one bay transversely but continuous over two or more spans longitudinally is suggested"--Abstract, page ii.

Application Of The Photoelastic Coating Method To Evaluate The Stress Distribution On The External Surface Of The Cap Of An Electrical Insulator, Harijeetsinh Jagtiani

Masters Theses

"The Photoelastic Coating Method was applied to find the surface stresses on the cap of an electrical insulator. The strain distribution was observed and photographed. This color photograph indicated a visible geography of the maximum shear strain distribution in the region of the insulator where the birefringent plastic was bonded with a reflective cement. The Oblique Incidence technique was used to determine the principal stresses from the maximum shear strain (or the principal strain difference) readings, obtained from Normal Incidence. The critical cross-section of the insulator head was optically located, giving an initiative for the re-design of the insulator cap. …

Thermal Degradation Of Poly (Methyl Methacrylate) In Solutions In A Closed System, Vikram Pranjivandas Parikh

Masters Theses

"A study has been made of the thermal degradation of poly (methyl methacrylate) of two different molecular weights, 2,303,000 and 43,000, in 1,2-dichloroethane in a closed system. The results indicated that the polymer having a molecular weight of 2,303,000 undergoes degradation while the low molecular weight polymer 43,000 undergoes reverse polymerization, and the molecular weight remains constant. The molecular weight of high molecular weight samples after 48 hours decreased from 2,303,000 to 2,232,000 and 1,690,400 at 50⁰C and at 98.5⁰C, respectively"--Abstract, page [i].

Model Study Of A Folded Plate Roof, Graham G. Sutherland

Masters Theses

"The purpose of this study was to conduct a model study of a folded plate roof in order to determine the feasability [sic] of using model studies as a method of design. Dimensional analysis was used to derive prediction equations for determining the stresses in two prototype structures, when the stresses in the model were known. One model and two prototype folded plate roofs were constructed of plexiglas [sic]. SR-4 strain gages were attached to the structures and strain readings taken as a uniform vertical load was applied in increments. From the strains the stresses at various points in the …

The Dielectric Properties Of A Synthetic Fluor-Mica Formed By Glass-Ceramic Fabrication Techniques, Ray Fred Schumacher

Masters Theses

"A tetrasilicic fluor-mica, K₂Mg₅Si₈O₂₀F₄, was synthesized, utilizing glass forming techniques and subsequent heat treating of the mica glass. Discs, approximately two inches in diameter, were formed and heat-treated at selected temperatures between 700⁰C. and 1150⁰C. for various time periods. Density change, weight loss, shrinkage, and dielectric properties were measured to determine the characteristics of this material"--Abstract, page ii.

Analog Simulation Of A Synchronous Machine, J. Derald Morgan

Masters Theses

"The problem presented here is a study by an analog computer simulation of a synchronous machine under balanced three phase, short-circuit conditions. The purpose is to obtain a solution that is more accurate than one obtained by approximate methods using transient and subtransient reactances as is often done. This simulation is accomplished by using an idealized synchronous machine. The equations relating voltage and currents in the machine, as well as speed and torque, are presented for simulation. The equations for the machine include the saliency of one member, as well as the effect of speed and the damper windings. A …

A Feedback Compensator Design For Linear Control Systems, Thsai-Ten Lin

Masters Theses

"The compensation process in control system engineering is indispensable. The addition of a compensator to a fixed plant can often make the system meet certain specifications easily. In this study an attempt was made to use a general purpose digital computer to design a feedback compensator. The method developed is first to determine the minimum gain of the amplifier and the number of compensator poles and zeros based on the given specifications. then free hand root-loci are plotted, with several combinations of possible compensation variables. These data are used as the open-loop transfer function from which the poles and zeros …

Matching Of A Horn Antenna To Its Dense Surrounding Media By The Use Of Artificial Dielectric Methods, Paul Arthur Ray

Masters Theses

"The purpose of this thesis is to design an artificial dielectric slug to match a horn in a media such as water and to discuss a method of determining experimentally its dielectric properties. The design is based on known artificial dielectric methods. The method of determining the dielectric properties is by microwave waveguide reflection techniques. This thesis deals with the theoretical aspects and suggests an experimental method of determining the practicability of such a matching method"--Abstract, page ii.

Infinite Beams On An Elastic Foundation, Shi-Peing Chang

Masters Theses

"In this paper a partial differential equation for the analysis of beams resting on an elastic foundation under dynamic load is presented. A solution for this equation is derived, and solutions for various boundary conditions of infinite beams resting on an elastic foundation are discussed. The application of the equation is demonstrated by an example of a moving load traveling along an infinite beam"--Abstract, page ii.

The Effect Of Small Alloy Additions On The Quench Induced Texture Of Alpha Uranium, Kenneth Ray Riggs

Masters Theses

"The preferential orientations produced in binary alloys of U-Si and U-Cr on plane sections perpendicular to the direction of heat flow by cooling from beta-phase temperatures were determined. The experimentally determined textures were presented using inverse pole figures. A definite and reproducible relationship was found to exist between the preferred orientation present at any position and the cooling rate which material at the position had experienced. It was found that the concentration of the alloying elements within the ranges studied had little detectable effect upon the observed relationship between the cooling rate and the resulting preferential orientation. It was postulated …

A Photoelastic Study Of The Effect Of Certain Geometric Variables On The Plane Stress Distribution In An Electrical Insulator Body, Richard L. Pendleton

Masters Theses

"Photoelastic models were used to indicate stress patterns in various geometrically designed shapes. Each model represented a two-dimensional cross-section of the interior portion of an axially symmetrical porcelain electrical insulator. Five different loading pins were combined with three loading heads to produce eleven models. The maximum stress in each model was determined using a photoelastic method of stress analysis. An attempt was made to select the best structural design to be used in an electrical insulator. The test results indicate that the most desirable stress distribution is obtained using a single step loading pin and that the loading head angle …

The Separation Of Radioactive Technetium And Zirconium By Electrodialysis And A Study Of The Behavior Of Technetium In Aqueous Solutions, William Victor Andoe

Masters Theses

"The rapid increase in radioisotope applications necessitates improved technology for separation and purification of the fission product elements. Electrodialysis techniques employing Permutit anion exchange membrane(3148) were used to separate technetium from zirconium. The method was based upon the stability of the pertechnetate ion in alkaline solutions and the precipitation of zirconium from alkaline solutions. The separation of radiotechnetium and radiozirconium was effected with a two cell electrodialysis unit employing an anion exchange membrane. The solution medium consisted of fluoride and nitrate ions which were made basic with sodium hydroxide. The minimum basicity for a good separation was 0.1N NaOH"--Abstract, page …

Field Permeability Determination Of Partially Saturated Fine Grained Soil, Edward G. Rapp

Masters Theses

"The determination of water permeability through a soil is necessary to estimate seepage losses from small reservoirs. At the present time, the methods available to conduct this determination in partially saturated fine grained soils are expensive and in most cases not commensurate with the cost or importance of the individual structure. This investigation was conducted to evaluate the use of a proposed, potentially inexpensive field procedure in this situation. A modified borehole apparatus was utilized in field tests to determine the permeability of a partially saturated soil deposit in place. Undisturbed samples from the same location were tested in the …

Design Of Non-Uniform Linear Antenna Arrays With Digitized Spacing And Amplitude Levels, Jack F. Morris

Masters Theses

"Recent developments in space exploration have shown a need for high resolution, high gain antennas. The introduction of non-uniform linear array theory has provided a means by which arrays may be designed to produce narrow main beams with fewer elements than required by uniform arrays. A general theory has not been developed, however, and the design engineer has been left with only trial-and-error methods with which to work. In this study a technique has been developed by which non-uniform antenna arrays may be synthesized to meet a given set of specifications with reasonable accuracy. The elements of the array are …

Permeability And Additive Absorption And Extraction In Lubricating Greases, Eugene Hsiung-Jen Tu

Masters Theses

"A permeability apparatus was used to measure the permeability coefficients of eight Lithium-Calcium greases and ten Baragel greases in which the viscosity and type of the oil component were varied. The oil present in each grease was used for its permeability measurement.

An improved sample packing technique was developed to improve the repeatability of permeability measurements. Repeatability of ± 3% was achieved. In general the permeability coefficients of the non-soap Baragel greases were higher than those of the lithium-calcium greases with comparable oil components, and those of greases containing paraffinic oils were higher than these containing naphthenic oils. The effect …

Epoxy Resin Admixture For Concrete, Kuo-Chu Hu

Masters Theses

"This thesis describes laboratory tests on concrete having epoxy as an admixture. Cylinders for compression and elastic modulus tests were cured under two different curing conditions, standard laboratory cure and a simulated job cure. Beams cured under laboratory conditions were tested for flexural strength. Test results show the compressive strength increases with an increase of epoxy content for job curing conditions. However, compressive and flexural strengths of specimens cured under laboratory conditions show a slight decrease. The elastic modulus of concrete containing epoxy also decreases in comparison to ordinary concrete"--Abstract, page ii.