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A Study Of Surface And Geometric Effects On The Nucleate Boiling Of Liquid Nitrogen And Liquid Argon From Atmospheric To The Critical Pressure, Calvin Benson Cobb

Doctoral Dissertations

"A maximum heat flux correlation was derived for corresponding states liquids and subsequently verified by the data collected in this study as well as data presented in the literature. By applying this correlation, one can predict maximum heat flux values at high pressures from maximum heat flux values measured at low pressures; however, to apply the correlation it is necessary to have at least one maximum heat flux value and the saturation temperature at which it was determined.

Contrary to existing correlations, it is shown that for any nucleate boiling heat transfer correlation to be truly general, it must include …

The Transient Dynamics Of Plane Mechanisms, Navnit Chhaganlal Mehta

Doctoral Dissertations

"Accurate determination of dynamic characteristics of mechanisms has become more important with increased requirements on speed, efficiency and precision. Many devices, such as circuit breakers and computing mechanisms, operate under purely transient conditions and actuation time places a serious limitation on the response of the system of which these devices are a part.

In the classical analysis, whether it be graphical or analytical, the mechanism is assigned a specified position and state of motion from which the forces required to produce the motion can be determined. The inverse problem of specifying the driving force and determining the resulting motion, which …

A Structural Investigation Of Bismuth Ferrate And The Bifeo₃-Pbzro₃-Pbtio₃ Ternary System, Gary D. Achenbach

Doctoral Dissertations

"Solid state reaction of Bi₂O₃ · Fe₂O₃ mixtures was shown to yield impure bismuth ferrate, BiFeO₃, containing Bi₂Fe₄O₉ and residual Bi₂O₃; this places the results of much of the literature based on BiFeO₃ prepared by this technique in suspect. Single phase polycrystalline BiFeO₃ was prepared by multiple nitric acid leaching of sintered samples which contained excess Bi₂O₃ to prevent the formation of Bi₂Fe₄O₉ during sintering. X-ray and neutron powder diffraction data indicate that …

An Investigation Of The Creep Characteristics Of Portland Cement Mortar Under Static And Dynamic Strain, Ikram-Ul-Haq Dar

Doctoral Dissertations

"The combined effect of static and dynamic loads on design of underground openings is currently receiving much attention. It is known that the time-dependent behavior of rock is considerably different when a dynamic load is superimposed on prestressed rock. The shape of an underground opening has a definite influence on the magnitude of the local stresses and these may be significantly larger than those due to the weight of the overlying rock alone. Under these conditions, even a small dynamic load in the form of vibrations caused by blasting, drilling and related operations may increase the stress beyond a critical …

Hydrogen Absorption And Corrosion Studies Of Zone-Refined Iron, Chang Don Kim

Doctoral Dissertations

"The lattice constants of zone-refined iron filings and iron whiskers are 2.86623 and 2.86626 Å at 25°C respectively. Their thermal expansion coefficients are both the same, 12.1 x 10⁻⁶ /°C at temperatures 10 - 65°C.

The influence of hydrogen on the lattice constant of iron was investigated and it was found that hydrogen has no effect (within the limits of errors) on the lattice constant of iron at room temperature regardless of the charging methods. However, at elevated temperatures hydrogen expands the iron lattice due to increased solubility of the gas. The lattice constant of iron in vacuum and in …

A Study Of The Anodic Oxidation Of Acetylene On Gold Electrodes, Jo Lisle Reed

Doctoral Dissertations

"The object of this investigation was to establish a mechanism for the anodic oxidation of acetylene on gold electrodes in aqueous solutions. It is known that anodic oxidation of organic compounds on gold electrodes produces a large number of organic intermediates and end products. Therefore, it appeared worthwhile to establish a mechanism that could provide a better understanding of the fuel cell electrode kinetics and possibly lead to new methods of organic syntheses"--Introduction, page 2.

Geochemical And Petrological Study Of The Precambrian Iron Metallogenic Province Of Southeast Missouri, Geza Kisvarsanyi

Doctoral Dissertations

"The general purpose of this dissertation was to investigate and establish petrological and geochemical relationships, if any, between the Precambrian iron deposits and associated host rocks. A more specific objective was to determine the distribution of some significant minor elements in the rocks and mineral deposits and to include specific mineralogical and petrological studies of the iron deposits and country rocks important to a better understanding of the genetic and geochemical relationships ... A primary task in the investigation was the study of the trace element population of individual iron deposits and establishment of differences, if they exist, between the …

A Contribution To The Knowledge Of The Amphipodous Crustacean, Ampithoe Valida, Smith 1873, Burdette Eugene Barrett

Doctoral Dissertations

No abstract provided.

Aeration Studies In Submerged Fermentations Using A Steam-Sterilizable Dissolved Oxygen Sensor Of Improved Design, Carl J. Wallace

Doctoral Dissertations

"Large-scale submerged fermentations have been important for many years for the production of antibiotics, vitamins, enzymes, etc.; however, aeration studies have been severely restricted in these processes because of the unavailability of adequate oxygen sensing equipment.

A steam-sterilizable oxygen sensor of improved design was developed out of an investigation of several potential sensors. This rapidly responding galvanic probe made use of a lead anode, a silver cathode, an acetate buffer as the electrolyte, and a one mil Teflon® membrane as the diffusion barrier. Its sensitivity was approximately 40 µamps and full response required approximately 5 minutes.

Use was made of …

An Investigation Of The Control Of Hydraulic Fracturing Through The Inclusions Of Prefractures, William Joseph Kabeiseman

Doctoral Dissertations

"Among the methods for determining the in-situ state of stress within the earth’s crust, hydraulic fracturing has been and is receiving much attention. This method, in principle, measures stress directly with no delicate electronic equipment required nor knowledge of the elastic modulus of the material.

This dissertation investigates experimentally whether or not control of fracture orientation can be achieved by the introduction of circular and elliptical prefractures along with sand inclusions into cast hydrostone blocks which are hydraulically fractured. A mathematical model is presented and analytically solved for the stress condition associated with a circular crack containing fluid pressure with …

Continuously Tapered Dielectric Matching Transitions For Waveguides, William E. Hord

Doctoral Dissertations

"Dielectric matching transitions at microwave frequencies are used for matching air filled waveguides into dielectric filled waveguides for maser work or into dielectric rod antennas. Also dielectric loading has been shown to improve the performance of the ferrite isolators.

The dielectric matching transitions that have been analyzed in the literature are of the stepped type. The continuously tapered dielectric matching transitions investigated in this dissertation provide increased bandwidth with very little increase of physical complexity.

The dissertation provides an analytical method for analysis and design for the continuously tapered dielectric matching transition. First-order and second-order approximate solutions for both symmetrical …

Some Geological And Magnetic Characteristics Of Buried And Resurrected Precambrian Hills Of Southeastern Missouri, James Edward Palmer

Doctoral Dissertations

"PURPOSE AND SCOPE OF INVESTIGATION The major purpose of this investigation was to determine by a comprehensive study various geological and magnetic characteristics of buried and resurrected Precambrian hills of the Central Ozarks. A second important objective was the determination of characteristics which might aid in the location of buried Precambrian hills. A final objective was the testing of the magnetic surface integration method for identification and determination of depth of buried Precambrian hills.

This investigation is limited to buried and resurrected Precambrian hills of the Central Ozarks. It is concerned primarily with the structure and stratigraphy of sediments adjacent …

Nonparametric Detection Of Signals Causing Arbitrary Changes In The Accompanying Noise Backgrounds, John Joseph Komo

Doctoral Dissertations

"The detection of signals in the presence of noise is an important problem in the field of communications. The detection problem is concerned with the design of systems which determine only the presence or absence of a signal which occurs with background noise. An example of considerable importance, which is encountered quite frequently in practice, is the radar detection problem. In the radar problem it is desired to determine the presence of a target by detecting the presence of a radar return signal in noise. Another example is the seismic exploration problem which utilizes the detection of reflected signals from …

The Anodic Behavior Of Zinc In Aqueous Salt Solutions, Yun-Chung Sun

Doctoral Dissertations

"The increasing demand for protective metals as coatings and non-corrosive alloys has caused extensive research on the fundamental behavior of metals in corrosive media. The problem of controlling the destructive process of metallic corrosion still exists and becomes urgent in this space age. The desirablity of metals such as beryllium, magnesium, and zinc in air frame and space structural units, because of their high strength to weight ratio, has been responsible for the considerable progress in their technology in recent years.

The basic mechanism of the anodic dissolution of metals such as zinc, cadmium, and magnesium in salt solution is …

The Anodic Dissolution Of Cadmium In Aqueous Solutions, San-Cheng Lai

Doctoral Dissertations

"The purpose of this investigation was to study the effect of cadmium ions on the anodic dissolution of cadmium in salt solutions of ·constant ionic strength. The concentration of the cadmium ions was varied from 0.001 to 1 N and the current density ranged from 0.001 to 0.1 amp•cm^-2. The temperature was controlled at 25°C.

....A mathematical model was postulated expressing the anodic dissolution rate as the sum of electrochemical, local corrosion, and disintegration rates."--Abstract, page iii.

An Investigation Of The Induction Heating Characteristics Of Powdered Susceptors Dispersed In A Non-Conducting Medium, Robert Leon Wright

Doctoral Dissertations

"This investigation determined some of the induction heating characteristics of powdered magnetite, iron and ferrosilicon susceptor dispersed in silica sand which had been coated with thermosetting resin. The powdered susceptor particles in the mixture were heated by the field of an induction coil, consequently heating the resin coated sand and bonding the sand grains together.

It was found that the type, relative amount,and particle size of the susceptor were important variables to be considered in the induction heating characteristics. Hysteresis losses in the susceptor particles, which are a function of the coil current, frequency, and permeability, appear to be the …

A Study Of The Supercooling Behavior Of High Purity Liquid Bismuth, B. L. Bramfitt

Doctoral Dissertations

"This investigation involves a study of the supercooling behavior of pure bismuth as affected by the melting atmosphere, the amount of superheat, and the intentional addition of metallic and non-metallic foreign materials to the melt. It was found that the amount of oxide on the melt surface is a controlling factor in the degree of supercooling obtainable in bismuth. In the presence of a thick bismuth oxide surface layer the amount of superheat below a 15°C drastically decreases the amount of supercooling due to the retention of nuclei in the surface film that promote nucleation upon cooling of the melt. …

Cenozoic And Recent Lunulitiform Bryozoans Of The Gulf And Atlantic Coasts, Ronald Greeley

Doctoral Dissertations

"Free, cup-shaped colonies of cheilostomatous bryozoans, equipped with vibracula, are termed lunulitiform bryozoans. This group is found in sandy and calcareous Cenozoic deposits of the Gulf and Atlantic Coastal Plains. Cupuliform bryozoans are taxonomically distinct from, but in many ways similar to, lunulitiform bryozoans; the two groups are frequently found together.

Known lunulitiform genera of the Gulf and Atlantic Coastal Plains are diagnosed and their species described: Lunulites Lamarck, fifteen species, one new; Oligotresium Gabb and Horn, six species, two new; Discoporella d'Orbigny, two species; Cupuladria Canu and Bassler, two species; Selenaria Busk, one species; Otionella Canu and Bassler, four …

Calculated Cohesive Energy Of The Ordered Copper-Gold Alloy Cu Au I, Richard W. Hannum

Doctoral Dissertations

"The ordered alloy CuAu is the fifty atomic per cent alloy in the copper-gold system. It was observed by Johansson and Linde(1) and was one of the first ordered alloys to be studied by x-ray diffraction methods(Z, 3). Two ordered superlattices of CuAu are observed. CuAu I exists below 380° C and has a tetragonal structure which is a slight distortion of the face- centered cubic. It is very highly ordered, with all copper and all gold atoms in alternate (002) planes, as shown in Figure 2. CuAu II, which exists between 380° and 415° C, is orthorhombic in structure(4) …

A Theoretical Approach To The Problem Of Determining Ejecta Volumes In A Gravitational Vacuumed Half-Space, William J. Karwoski

Doctoral Dissertations

"The formation of an explosion crater is a highly complex process. All of the pertinent parameters governing the mechanisms of cratering are not clearly understood or known. Many cratering experiments were performed in desert alluvium in an effort to relate crater dimensions with charge weight and depth of burst. Various scaling laws were devised in an attempt to correlate the data gathered from these experiments. When cube-root scaling was used to correlate results of tests conducted at a constant scaled depth of burst, larger charge weights consistently gave smaller scaled results. This was particularly true of apparent crater volume. When …

Turbulence Measurements In Polymer Solutions Using Hot-Film Anemometry, Gary Kent Patterson

Doctoral Dissertations

"Hot-film anemometry was used to study the detailed structure of turbulence (intensities, energy spectra, and auto-correlations) in Newtonian solvents, non-drag reducing polymer solutions, and drag reducing polymer solutions. This was done in two smooth wall tubes with diameters of 1.0 inch and 2.0 inches. A probe traversing mechanism was used for measurements at radial positions from the center to as near the wall as possible for both the film probes (r/a=0.85 in the 2-inch tube) and the impact tubes (r/ a=0.98). The impact tubes were used to measure velocities for film probe calibration.

The solvents used in this investigation were …

The Statistical Mechanics Of Kink Interactions, Michael Brewer Mcneil

Doctoral Dissertations

"Using a potential derived from continuum elasticity, the interactions between kinks on a dislocation line are studied as special cases of the problem of a one-dimensional system of interacting particles. By the use of constant pressure ensembles, the principal kink-interaction problems of physical interest are solved. The application of these solutions to the theoretical analyses of work hardening and internal friction is explored and comparisons made to previous work in which kink interactions were neglected; it is found that, as would be expected, variations of equilibrium kink populations with external stress cannot account for the Bordoni peak, which must therefore …

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 …

Drag Reduction In Newtonian Polymer Solutions, Harry C. Hershey

Doctoral Dissertations

"Prior work in the area of drag reduction has been mainly limited to aqueous solutions. Theoretical and empirical analyses of the resulting data in aqueous solutions have been hindered by the fact that some polymers cause drag reduction and others do not...This investigation was directed to the study of how the size and configuration of the polymer molecule in solution affected drag reduction and the related phenomenon of turbulence suppression. Apparatuses were designed and built to measure viscometric flow, curves, friction factors, velocity profiles, and normal stresses (by a jet thrust technique developed by Metzner and associates)"--Summary, page 1-2.

An Introduction To Linear Time-Variant Digital Filtering Of Seismic Data, Richard Harold Lassley

Doctoral Dissertations

"The exploration geophysicist is constantly searching for new and better methods for analyzing seismic data. The primary purpose of this dissertation is to introduce linear time-variant digital filters as a technique for the filtering of seismic data. Methods of characterizing linear time-variant digital filters are discussed in general terms. The advantages of the different impulse and frequency responses are cited. In addition, the meanings and possible interpretations of the time and frequency variables introduced are considered. The concept of linear time-variant digital delay filters is presented along with their relationship to impulse responses. A pictorial diagram of discrete time-variant impulse …

A Study Of (Deuteron,Proton) Reactions On Light Nuclei From 200 To 350 Kev, Joel Edward Henkel

Doctoral Dissertations

No abstract provided.

Stratigraphy, Sedimentation And Structure Of The Upper Cherokee And Lower Marmaton (Pennsylvanian) Rocks Of Bates County, And Portions Of Henry And Vernon Counties, Missouri, Richard J. Gentile

Doctoral Dissertations

"The major purpose of this dissertation is to describe in detail the stratigraphy of the upper Cherokee and lower Marmaton groups of the Middle Pennsylvanian, Desmoinesian Series in a portion of western Missouri. The stratigraphy of the upper Cherokee and lower Marmaton groups in areas of Kansas west of the project area has been studied by several workers. The most recent contributions have been by Jewett in 1941 and 1945, and by Howe in 1956. Detailed geological mapping also has been completed under the direction of the Missouri Geological Survey in areas to the east of the project area. Most …

The Thermodynamics Of The Zno-Fe₂O₃-Fe₃O₄ System, Robert Lee Benner

Doctoral Dissertations

"The purpose of this investigation was to (1) experimentally locate certain phase boundaries in three isothermal sections of the zinc oxide - ferric oxide - magnetite phase diagram, (2) to experimentally determine some of the thermodynamic properties of the zinc oxide - ferric oxide - magnetite system, (3) to use the thermodynamic properties of the zinc oxide - ferric oxide - magnetite system to evaluate the pseudo-binary system between zinc ferrite and magnetite, (4) to construct a compound stability diagram for the zinc-iron-oxygen-sulfer system"--Introduction, Statement of the Problem, page [1].

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 …

Variation In Gold Content Of Minerals Of The Marysville Quartz Diorite Stock, Montana, Erwin Joseph Mantei

Doctoral Dissertations

"The purpose of this thesis was to study the amount and distribution of gold in the minerals of the Marysville quartz diorite stock, Montana. Twenty-eight rock samples were collected from various parts of the Marysville Stock, using a NS-EW grid sample pattern. Thirty additional samples were collected from selected localities and from the vicinity of the gold mines which occur around the periphery of the stock. By use of a hand magnet and a Frantz isodynamic separator, the magnetite, biotite, hornblende, and quartz-feldspar portions of the various rock samples were isolated and purified to between 90-99 percent purity. Eighteen thin …