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A Study Of The Bonding By Air-Setting Refractory Mortar At Elevated Temperatures, Bhikhubhai Mahadeo Sedalia

Doctoral Dissertations

"The importance of a suitable material for the laying of bricks in furnace and kiln construction has been recognized by the refractory industry for a long time. It is necessary that a strong bond should develop between the bricks to impart strength to the entire construction work. A weak joint would form the weakest link and dangerously weaken the whole structure.

Such being the importance of the bond, the refractory industry has made quite an effort to develop jointing materials which would produce strong bonds. During the last two decades, due to intensive research and development work, many good bonding …

Carbon Monoxide Attack Of Refractories, William A. Frad

Doctoral Dissertations

"The disintegration and failure of fire clay refractories due to the action of carbon monoxide has been studied tor a period at about fifty years. The most important application is in blast furnace refractories. Similar failures due to carbon deposition, involving other gases such as methane, have been noted and less extensively studied. Failures due to the action of gases other than carbon monoxide are beyond the scope of this thesis. Occasional attempts to find some agent to prevent disintegration have been mentioned in the literature. In this study the number of such substances and the results of their action …

Hydrogen Overvoltage On Titanium, Sheng-Tai Shih

Doctoral Dissertations

"The hydrogen overvoltage has been defined as the difference between the potential of the working electrode (cathode) and the theoretical reversible value for the same solution. This definition brings out the difficulty involved in the measurement of the "theoretical reversible potential for the same solution” as the potential of the hydrogen electrode in such a solution is usually different from the value of a standard reversible hydrogen electrode, for which the activity of hydrogen ions is set as being “1” and the potential arbitrarily set as being “0”. Besides, it is sometimes necessary to add addition agents to the solution …

The Rate Of Dissolution Of Aluminum In Hydrofluoric Acid, Yen-Ngen Wang

Doctoral Dissertations

"Pure aluminum has a relatively low strength, and its use is, therefore, rather limited. However, the resistance of pure aluminum to the attack of acids and many neutral solutions is higher than that of less pure aluminum or most of the aluminum-base alloys. For this reason, alclad alloy sheets, are made with a coating of pure aluminum on one or both sides of an aluminum alloy core. The coating is metallurgically bonded to the core over the entire area of contact. Thus the coating electrochemically protects the core from corrosive attack.

Aluminum is more negative in the electrochemical series than …

An Investigation Of The Characteristics Of High Alumina Refractory Castables, Gajendra Nath Mohanty

Doctoral Dissertations

"Refractory castables or concretes, a comparatively new member of the refractories family, are an admixture of highly aluminous cements and graded refractory aggregates, blended in predetermined proportions very much like structural concrete. The refractory aggregates must contain a large amount of fines contrary to the requirements of ordinary concrete. Unlike the Portland cements, which are mainly combinations of calcium silicates, the highly aluminous cements are predominantly calcium aluminates. They are comparatively of a refractory natures, having the hydraulic setting property combined also with high early strength. The discovery of the fact that these refractory concretes could be cast, in situ, …

A Study Of The Deformation Texture And Its Variation In Cold Drawn Nickel Rods, Krishan Kumar Tangri

Doctoral Dissertations

"The production of rods by cold drawing is a development of recent years as compared to other methods of fabrication. Though a good many investigations correlating the observed mechanical properties to the mill practices employed have been reported, the results nevertheless are more of a qualitative and empirical nature. It is well known that the physical properties of a metal product are related to its deformation textures which are characteristic of the metal and the fabricating method used. Thus a study of the deformation textures of cold-drawn rods, specially by x-ray diffraction techniques should provide a much more precise and …

Geochemical Prospecting Applied To The Illinois-Kentucky Fluorspar Area, Matthew Peter Nackowski

Doctoral Dissertations

"This study was completed to determine whether geochemical methods of prospecting could be applied to the search for fluorspar deposits in the Illinois-Kentucky fluorspar district.

During the course of the study, aspects of the geochemical cycle of fluorine under the climatic environment encountered were noted in the zone of weathering.

The Illinois-Kentucky fluorspar district supplies a large portion of the fluorite consumed in the United States. The producing deposits are of two geologic types. The vein deposits occur as nearly vertical tabular lenses or pods which occupy fractures. These deposits may reach the bedrock surface, but in any case, the …

Shaped Charges: Their Mechanism And Applications In Mining, Pranlal Girdharlal Sheth

Doctoral Dissertations

"A shaped charge, confined or unconfined, is a unit of explosive material with a cavity or hollow at the base. It behaves differently than an ordinary charge, and, when detonated, has been found to produce curious effects of concentrating the force of the explosive on an area opposite the cavity"--Introduction, page 1.

An Investigation Of The Deformation Textures Of Titanium, Dean Nesbit Williams

Doctoral Dissertations

"With the increase in production of titanium in recent years has come a great interest in the mechanical properties and in the possible uses of this metal. Due to the affinity of titanium for oxygen, nitrogen, carbon, and hydrogen, and the market effect of these elements on the mechanical properties, much of the work previously reported is unreliable. As purer commercial grades of titanium and high purity iodide titanium have become available for examination, research has been undertaken to correct and expand the knowledge of the properties of titanium. Although the uses of titanium are limited at the present time, …

A Study Of The Dissolution Of Titanium In Acids With Ammonium Fluoride Added, Charles Burroughs Gill

Doctoral Dissertations

"Titanium can no longer be considered a rare metal, even though the modern era of its production came into being only a few years ago. The first discovery of titanium was in 1791 by an English clergyman, the Reverend William Gregor, and the name titanium became universally adopted when so called by a German mineralogist, Martin Klaproth, who rediscovered titanium three years later. Not until 1887 was the relatively pure, 75 percent, metal prepared by L. F. Nilson and O. Pettersson, whose experiments were repeated in 1910 by M. A. Hunter. Hunter is given credit for producing the first metallic …

Determination Of Progressive Corrosion Of Clay Flux Blocks, Ved Prakash Maheshwary

Doctoral Dissertations

"The Problem. Corrosion of refractories by molten corrosive liquids like molten slags and glasses is of general occurrence in those parts of the furnaces where they come in contact with the liquids. The life of a furnace generally depends upon the progressive rate of corrosion of the refractories by the slags and glasses. There have been various methods used by the investigators to ascertain the useful life of a refractory product before its use in the furnaces, but the problem is so complex that even after decades of research work by the research engineers and technologists a satisfactory and easy …

The Relationship Of Regional Structural Geology To The Ore Deposits In The Southeastern Missouri Mining District, Jack Alexander James

Doctoral Dissertations

"The lead deposits in the Southeastern Missouri mining district have been examined by numerous geologists and mining engineers since the original discovery about 1720. A list of the men who have reported on them includes some of the outstanding students of ore deposits.

The regional geology in the mining district either was unknown or only vaguely known when most of the early examinations were made, and the discussions of the structural geology are restricted in scope owing to the lack of detailed information. The reports based on these examinations, although excellent for their time, are incomplete in view of the …

The Underground Electrocarbonization And Gasification Of Mineral Fuels, Erich Sarapuu

Doctoral Dissertations

"The development of underground gasification methods for recovering mineral fuels is comparatively recent and several methods have been evolved for treating the various source materials. The problem of recovering solid and liquid fuels by underground gasification in gaseous form was primarily approached by means of opening underground entries which created the required fire-drift for starting the gasification in place.

Increasing knowledge of the whole problem of gasification in situ led to the evolution of new improvements in the underground gasification technique and, in the course of progressive research the preparations required for starting the gasification were accomplished from the surface. …

Precise Lattice Parameter Determinations Of Diamond Silicon And Germanium By The Asymmetric Method, Esrefettin Zeki Aka

Doctoral Dissertations

"The construction of the apparatus for production of powder patterns at a definite temperature and the technique for evaluation of x-ray powder patterns by the asymmetric method are described in detail, and the mode of error elimination is discussed.

A new scanning device is designed for use in x-ray diffraction work.

A modified method is described for the determination of densities of solids, which eliminates some of the difficulties interfering with other similar methods thus far proposed. Formulae are derived for the calculation of density as well as for reduction of density at a desired temperature.

The following conclusion are …

An Experimental Evaluation Of Explosives In Blasting Limestone And Granite, Harve Preston Nelson

Doctoral Dissertations

"The purpose of this study was the evaluation of military and commercial explosives. A standardized index of effectiveness was used as the basis of comparison.

Testing was conducted at the Experimental Mine of Missouri School of Mines and Metallurgy at Rolla, Missouri, and at Graniteville, Missouri. At the school mine, 16 drift rounds, 8 slab rounds and 70 quarry tests were made in the dolomitic limestone. This rock, known locally as the Quarry Ledge of the Jefferson City formation, is of Ordovician Age"--Abstract, page ii.

The Volatility Of Metallic Sulfides And Their Treatment By Vacuum Metallurgy, Chi-Mei Hsiao

Doctoral Dissertations

"The purpose of this investigation is to determine the vapor pressure or volatility of the sulfides of the following metals by Langmuir's method: a) Zinc b) Cadmium c) Mercury d) Manganese e) Tin f) Lead g) Arsenic h) Antimony i) Molybdenum J) Iron k) Cobalt l) Nickel m) Copper n) Silver o) Calcium p) Aluminum.

The relation of this property to the position of the metals in the periodic table will be discussed, thus the vapor pressure or volatility of the remaining metals can be predicted as to the order of magnitude if the law of periodicity holds.

The possible …

Measurement Of Flotation Rate As A Function Of Particle Size, Thomas Martin Morris

Doctoral Dissertations

“The Problem. The rate of flotation of solid particles determines the percentage recovery of these particles which can be obtained during a given time interval. An examination of operating data from a flotation plant shows that percentage recovery varies with the size of particle.

Many investigators have explored the problem of measuring flotation rate. In most cases the results obtained were expressed qualitatively. The results obtained by one worker were often at variance with results reported by another worker.

This investigation was undertaken with the object of (1) quantitatively measuring the rate of flotation of various sizes of particles and …

A Study Of The Dissolution Of Titanium In Acids With Emphasis On Hydrofluoric Acid, Ping-Chao Chen

Doctoral Dissertations

"Titanium is practically a new metal. Although it was discovered by W. Gregor in 1791, the pure metal was not prepared until 1910 by M. A. Hunter, and it is only very recently that tremendous interest has been focused on this new metal, as evidenced by the activities of numerous leading laboratories and pilot plants.

The reasons that Ti is gaining increasing attention may be attributed to the natural abundance of Ti ores in reasonable concentration and, what is more important, to its unusual combination of physical and chemical properties. According to F. W. Clark’s classical geochemical data, Ti amounts …

A Study Of Relative Ionic Mobility Of Alkali Ions In Dilute Alkali-Boron Trioxide Glasses As Deduced From Space Charge Considerations, Theodore J. Planje

Doctoral Dissertations

"The extensive investigations in the past have conclusively established that the alkali ions are responsible for the electrical conductivity of glass in both the brittle and viscous states; however, with the exception of one investigation in the brittle state, little consideration has been given to determination of the mobility of the alkali ion in such glassy systems. A review of the literature pertaining to the electrical conductivity of glass is presented.

A method, based on the rate of development of the ionic space charge responsible for polarization of conductivity cell employing direct current voltages, is proposed as a means for …

A Study Of The Gelation Of Air-Setting Refractory Mortars, James Irving Mueller

Doctoral Dissertations

"Three basic mortar formulae were used in this investigation, each mix having some different materials present and each having its own gelling characteristics. The study was directed along the theory that the dry materials used play an important part in the hardening. Certain admixtures were tested and several were found to improve the workability after storage. The presence of additional sodium ions in the mortar was found to be helpful in overcoming the gelation but these tended to lower the refractoriness of the mortar.

A study was made of the base exchange capacities of the dry materials and the material …

A Study Of Certain Ferromagnetic Alloys In The Systems Copper-Manganese-Indium And Copper-Manganese-Gallium, Frederick Arthur Hames

Doctoral Dissertations

"In 1898 F. Heusler discovered that certain alloys containing only copper, manganese, and tin are ferromagnetic. Since that time, ferromagnetic alloys have been reported to occur in the ternary systems copper-manganese-aluminum, copper-manganese-arsenic, copper-manganese-boron, copper-manganese-antimony, copper-manganese-zinc, silver-manganese-aluminum, and silver-manganese-tin. Such ferromagnetic alloys containing only non-ferromagnetic elements have come to be called "Heusler alloys."

From the metallographic standpoint, the ferromagnetic copper-manganese-aluminum and copper-manganese-tin alloys have been the most fully investigated of the Heusler alloys. These alloys owe their ferromagnetism to the beta phases in their respective systems. The structure of the beta phase is based on a body-centered cubic lattice.

In view …

A Study Of The Flow Properties Of Concentrated Clay-Water Mixtures, William Joseph Smothers

Doctoral Dissertations

"The study of flow properties of many substances is of prime importance in varied industries. The ceramic industry is mainly concerned with these measurements on a relatively stiff ceramic body, i.e., one which contains only enough water to retain its shape after the deforming force is relieved.

Various types of instruments have been devised to measure flow properties in the so-called "true plastic range." Since the primary measurements were made on instruments of the transpiration type to devise the laws of viscous and plastic flow, it was felt that an instrument employing the flow of the plastic material through an …

Pyrochemical Changes In Missouri Halloysite, Frank Joseph Zvanut

Doctoral Dissertations

"For centuries it has been known that the application of heat to a clay or a clay body produces changes that make it an entirely different substance from the original raw clay. Ever since the earliest civilizations produced crude building brick by baking formed clay bodies in the sun's rays, mankind has been speculating on the nature of the changes that convert soft, friable, plastic clays into hard, strong, non-plastic, rock-like masses. It has been only within the last two decades, however, that progress has been made in the solution of problems dealing with the resultant products in fired clay …