Engineering Commons^™

Treatment Of Zinc Crusts By Vacuum Distillation, Chang-Hsu Shih

Masters Theses

"The purpose of this research is to investigate the possibility of obtaining reasonably pure silver from the zinc crusts by vacuum distillation in one step. The effect of temperature, pressure, particle size, and time of distillation will be determined. The behavior of other constituents in the crusts are also to be studied"--Introduction, page 5.

A Study Of Cathode Drift Compensation In D-C Amplifiers, Joseph W. Rittenhouse

Masters Theses

"The expression, cathode drift, has to do with the random variations in vacuum tube plate current which are attributable to similar variations in emission velocities of electrons leaving hot cathodes. The fact that these random current changes appear to result from spurious drifts in cathode potential, since all other electrode potentials are unrelated to them, give rise to the expression, cathode drift...The problem with which this paper is concerned is a study of some of the possibilities of compensating for cathode drift effects in a single amplifier stage. Specifically, this paper will: (A) present a detailed mathematical and graphical analysis …

Automatic Wheel Balancer For Automobile Wheel, Frederick Eugene Nevin

Masters Theses

"Automobiles of today have been so constructed that greater speeds under safer conditions now exist. One of the improvements has been the low pressure tire. These tires carrying less pressure necessitates a casing of greater volume. This has created a tire of greater thickness in the axial direction but at the same time has decreased the diameter. Because of these innovations in present-day tires the author believes the wheel assembly (tire, tube, wheel, and brake drum) should be considered as a rotating cylinder not as a rotating disk. This being the case, the condition of dynamic unbalance is more critical. …

The Establishment And Analysis Of A Triangulation System For The Teaching Of Advanced Surveying, Philip Blaine Newlin

Masters Theses

"The first thought of establishing a triangulation system for the University of Arizona student work was conceived early in the fall of 1947, when the author first learned that he would be in charge of the advanced surveying field parties during the spring semester. These men were to be instructed in the accepted manner of conducting surveys of higher order. This would include the measuring of a base line of second or first order accuracy, the turning of horizontal angles with this same degree of accuracy, the determination of the azimuth of the lines by astronomical observations, the running of …

Comparative Study Of The Collecting Property Of Naphthenic Acids With Oleic Acid As Applied To Calcite, Hematite, Barite, And Fluorspar, Siddhi Nath Mukherji

Masters Theses

"The present investigation was undertaken to find out any comparable collecting property of some of the industrial naphthenic acids available in the market with that of commercial grade of oleic acid so that some information may be available in selecting naphthenic acids as flotation collectors. In the flotation industry, usefulness of oleic acid as non-metallic minerals collector is well established. On the other hand, the use of naphthenic acids as flotation collector has been reported only in few cases. Even in those cases, no attempt has been made to correlate their collecting properties with that of their physical and chemical …

Effect Of Transition Elements On The Transmittance Of B₂O₃ Glasses, Chandubhai Gordhanbhai Amin

Masters Theses

"For many years, boric oxide has been used extensively as a minor constituents in silicate glasses, because of its beneficial influence on their physical properties as well as on glass melting processes; but when used without silica or in too large proportion, the resulting glasses lack chemical durability...Because of its detrimental effect as a major constituent in silicate glasses or in borate glasses, very little work has been done on borate glasses, especially on colored borate glasses...The purpose of this investigation is to find out the effect of the transition elements on the transmission curves of the colored borate glasses"--Introduction, …

A Correlation Of Formulas For The Flow Of Fluids In Pipes, John Gorman Duba

Masters Theses

"At present there exist two quite distinct fields in fluid flow in pipes, the one in water supply and the other in the petroleum industry. It is the purpose of this paper to discuss the various pipeline flow formulas as used in both fields and to correlate the exponential type formula which is much used in practice with the Nikuradse curves obtained in the laboratory"--A Brief Historical Review, page 5.

Effect Of Titanium Dioxide As A Mineralizer In Silica Brick, Henry Clay Brassfield

Masters Theses

"The magnitude of the thermal expansion of silica brick and its inability to withstand rapid temperature changes gives rise to problems of considerable importance in the manufacture of silica brick. In firing the silica brick, mineralogical changes occur in the quartzite from which the brick is made, in which minerals of lower specific gravity are formed. This results in a permanent expansion of the brick. These mineralogical changes have been thoroughly studied and considerable information is known on the different forms of silica produced at the higher temperatures. If the conditions of firing are such that these changes have progressed …

The Application Of The Relaxation Method To The Solution Of Problems Involving The Flow Of Fluids Through Porous Media, Alexander Antoine Zwierzchowski

Masters Theses

"The purpose of this investigation is to determine the feasibility of applying the relaxation method of mathematical analysis to the solution of problems in rheology. The relaxation method was first introduced by R. V. Southwell who applied it to the problem of electrical conductivity. It was later used by M. W. Emmons to solve two-dimensional heat conduction problems. The steady-state flow of fluids through porous media can be difficult or impossible by the usual analytical methods even with rather simple boundary conditions. The relaxation method promises to provide an easier method of solution and to provide a means of solving …

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 …

X-Ray Investigations Of The Metal Deposits Resulting From The Electrochemical Displacement Process, Cheng Chih Fang

Masters Theses

"The principle of electrochemical displacement has been well established in the science of chemistry and applied as a commercial process in some metallurgical processes, such as the cementation process and the immersion method of metal coatings. According to the EMF series of the metals, the upper, the more electronegative metal,* (*Here the term of 'electronegative' means the metal possessing high electrolytic solution pressure and going into the solution with the formation of positive ions. Some authors preferred to use 'electropositive' instead of 'electronegative', referring to the ions which are electropositive during dissolution.) will displace the lower, the more electropositive one, …

A Preliminary Investigation Of The Titanium-Copper Equilibrium System, August Robert Savu

Masters Theses

"The element titanium has a high degree of chemical activity at room temperature when in a finely divided condition. In the massive state this activity is only exhibited at high temperatures. The powdered metal is highly pyrophoric. Titanium forms quite stable sulphides and carbides, although these are subject to oxidation at high temperatures. It also form nitrides. Titanium being a transitional element forms hydrides with hydrogen which are stable at ordinary temperatures, but which dissociate at red heat liberating the hydrogen and leaving the metallic titanium in a very active state. Alloys are formed with such metals as aluminum, manganese, …

Efficiency Of Various Types Of Reinforcement In Controlling Opening Of Cracks In Concrete Pavements, Frederick Richard Heartz

Masters Theses

"To date very little work has been done on the subject of the amount of crack opening for different loads on concrete pavement. It is a known fact that these cracks must be held together sufficiently to have aggregate interlocking action if the pavement is to transfer loads from one edge of a crack to the other. The maximum permissable [sic] opening has been set at .027 inches by the Highway Research Board. The author has attempted in this investigations (1) to determine the effect of different spacing and different sizes of longitudinal and transverse wires in controlling crack opening …

The Theory Of Limit Design As Applied To The Design Of A Continuous Beam Over Three Supports, Robert F. Davidson

Masters Theses

"The theory of Limit Design is the application of the theory of Plasticity to the estimation of the actual carrying capacity of a structure. In this theory, as it is applied to statistically indeterminate structures, the areas of most unfavorable stress are allowed to be stressed beyond the yield point and into the plastic range of stress. It was formerly held that, by assuming elastic behavior, all questions of strength of materials that concern the Structural Engineer were capable of solution. However, it is now becoming recognized, from actual measurements of deformations of structures and from tests carried to near …

Reduction Of Zinc Sulphide In A Vacuum, Tien-Shih Liu

Masters Theses

"The successful large scale commercial application of high vacuum for high temperature metallurgical operations is a comparatively new development. The use of Pidgeon and the carbothermic processes for the production of magnesium during the war forced a perfection of both equipments and techniques for high vacuum operations. This opens broadly the way for a great expansion of vacuum metallurgy. Vacuum operation is thus no more a laboratory method - it is a kind of industrial practice. Many metallurgical operations, which cannot be carried out by ordinary processes, are made feasible when conducted in a reduced pressure. typical examples are the …

A Graphic Method For Determining Pressure Losses Due To Air Friction In Mine Airways, Robert F. Bruzewski

Masters Theses

"One of the most important factors that influence the selection of a fan or blower for circulating a desired quantity of air through mine workings is the total pressure that is required to overcome the resistance of the airways. Ordinarily, the major portion of this resistance is that caused by friction of the moving air on the surface of the airways. The pressure that is required to overcome this frictional resistance is calculated by means of the friction formula"--Introduction, page 1.

Design Of A Wind Tunnel For The Missouri School Of Mines And Metallurgy, William E. Speece

Masters Theses

"For some time there has been a need for a wind tunnel at the School of Mines for experimental work in the Civil and Mechanical Engineering Departments. With the expanding program and the possibility of establishing an Aeronautical Engineering School here, the need will be even more pronounced. So the problem will be of definite practical value. It was the original idea to design a small tunnel, build the tunnel, and to run a series of smoke tests on various structural models. However, after discussing the possibility of such a problem with school authorities, it was decided that if a …