Digital Commons Network^™

Development Of A Simple Bar Method Thermal Conductivity Test, V. J. Flanigan

Masters Theses

"A linear flow bar method type apparatus was set up for finding thermal conductivities by comparison techniques. Comparison technique consist of using a standard specimen where the thermal conductivity is known and comparing it to the unknown specimens to find their conductivity. Apparatus of this type usually uses thermocouples for the required temperature measurements, but thermistors were used in this experiment. The thermistors used required calibration to measure accurate temperatures and this was accomplished by using the known temperatures of the changes of state of some common materials. Five alloys were used to evaluate the method: SAE 1020 steel, gray …

Velocity Distribution Induced By Free Jet Impact On A Stilling Basin, Sedat Özkol

Masters Theses

"At present, the use of the free jet impacting on a stilling basin as an energy dissipator is not very common, as there is very little information available concerning this particular field. However, if conditions are favorable, this type of energy dissipator will be quite economical to construct.

In this paper it was found that the hydraulic behavior of the free jet impacting on a stilling basin can be determined to a degree which may be considered accurate for practical purposes. It was also shown that given the free jet velocity, the magnitudes of the velocities at the critical points …

Transpiration Cooling Of A Porous Plate, Stephan A. Sayegh

Masters Theses

"Transpiration cooling has long been known as an effective way of removing heat from porous materials. This thesis is a new approach to one of the problems of transpiration cooling in the steady state.

The specific problem considered here is that of a uniform porous plate through which a liquid is forced. This liquid vaporizes at a short distance from the surface through which it is forced and leaves the porous plate at the other surface which is exposed to hot gases. It also protects the hot surface by forming an insulating layer between that surface and the hot gases. …

Analysis Of Flat Plates By Reaction Distribution Method, David D. W. Yang

Masters Theses

"This study was made to analyze rectangular flat plates by the method of Reaction Distribution and to compare results obtained by this method with that of other methods. The basic approach is to divide the plate into an equivalent grid system and introduce temporary supports at the intersecting joints. The results from this study shows that the Reaction Distribution method is useful in a qualitative analysis of the behavior in a plate but is less satisfactory in obtaining reliable quantitative results"--Abstract, page 2.

A Study Of The Permeability And Separation Of Carbon Dioxide And Hydrogen By Gaseous Diffusion Employing Barriers Of Polystyrene, Carl J. Wallace

Masters Theses

"The purpose of this investigation was to study the permeability and separation of carbon dioxide and hydrogen by gaseous diffusion employing barriers of polystyrene. The offset of temperature and barrier thickness on the permeability and separation of carbon dioxide and hydrogen wore Investigated for barriers of one, three, and five-mil thicknesses and for temperatures of 26, 35, 45, and 50 degrees centigrade.

With an increase in barrier thickness of one to five- mils, the permeability of carbon dioxide decreased to one-fourth of its value at the one-mil thickness. The hydrogen permeability decreased to approximately two- thirds of its value at …

A Study Of Composite Beams Made To Find An Approximate Relationship Between The Top And Bottom Flange Steel Ratio, Murli U. Hasrajani

Masters Theses

"At present in building construction the use of the composite beams is not very common. The use of the concrete beams is seen in almost all construction. By using composite beams in building construction more durability and savings in cost could be achieved. This paper shows an approximate design procedure which could be followed without running a number of trials with different sections to arrive at the required one. The ratio of top flange steel to the bottom flange steel can be determined if one knows the loads, span and the depth of the beam required"--Abstract, page i.

Transpiration Cooling Of A Heat Generating Porous Plate, M. K. A. Hameed

Masters Theses

"This investigation is a continuation of a thesis by T. S. Purewal. Several of the simplifying assumptions made by the above author are either ignored or the justifiability of such assumptions is probed into in order to obtain a more rigorous solution. Effects of the assorted grain size, non-Newtonian cooling, direction of coolant flow, thickness of the porous heat generating plate, specific heat of the coolant, and compressibility of the coolant are investigated in this thesis. Variation of maximum temperature of both coolant and the solid material for different types of heat source distribution are also studied.

As the grain …

A Study Of The Dissolution Of Zr-O Alloys In Hydrofluoric Acid, Wayne Gilbert Custead

Doctoral Dissertations

"The purpose of this investigation was to ascertain and explain, if possible, the effect of oxygen in the metal on the kinetics and electrochemistry of the reaction of zirconium in hydrofluoric acid solutions. This entailed the determination of the effect of oxygen on the dissolution rates, activation energies, dissolution potentials, and difference effect for zirconium in hydrofluoric acid and hydrofluoric-hydrochloric acid mixtures.

The alpha-phase solid solutions of oxygen and zirconium were synthesized by the powder-metallurgy technique. Both the alloy analysis and dissolution rates were obtained by the gas evolution method according to the reaction:

ZrO_x + 4HF → ZrF …

Statistical Analysis Of Fracture Stresses Of Triaxial Porcelain Bodies, Robert E. Moore

Doctoral Dissertations

"Triaxial porcelain bodies containing various forms of silica, quartz, cristobalite and fused silica, were strength tested in bending. Significance tests were employed to discern real differences in the strength sample statistics caused by the various forms of silica. Firings were performed at three temperature levels. The differences in strength sample statistics were correlated to the microstructures of these silica porcelains.

A triaxial alumina porcelain body was employed as a model brittle solid for a study of the effect of flaw density on mean fracture stress. The flaws were introduced in the form of large diameter (d̄ = 115 microns) rounded …

An Investigation Of The Deformation Textures Of Cobalt, Roy Carl Wilcox

Doctoral Dissertations

"Deformation textures of various cobalt structures as a result of cold rolling together with some annealing textures were studied. The textures of cobalt were determined using a modification of the Schulz-Decker Geiger counter technique. Pole figures of the (1011), (0001) and (1010) planes were constructed. Also, a study of the microhardness of cobalt was made.

Microhardness tests were performed on various cobalt structures, in both the cold rolled and unworked conditions. The microhardness was found to vary with the source of the cobalt, the crystal orientation, and the amount of deformation and twinning. Deformation lines about the hardness impressions diffused …

Lattice Parameters, Densities And Imperfections In Indium And Indium-Cadmium Alloys Rich In Indium, Paluri Bhimeswara Rao

Doctoral Dissertations

"An investigation of perfection of the structure of the indium-cadmium system was suggested by the interesting properties of indium and its cadmium alloys. The lattice of indium, though tetragonal, may be considered as distorted cubic, its axial ratio being 1.0767 at 20°C. Furthermore earlier studies have revealed a transformation of the tetragonal structure to cubic in the presence of cadmium.

To determine the perfection or soundness of the indium and indium-cadmium alloys rich in indium, pure indium (99.999 per cent purity) and eight samples of the indium-cadmium alloys ranging in composition from 2.977 to 10.015 per cent by weight of …

A Study Of Segregation In Cast Aluminum-Uranium Alloys, B. L. Bramfitt

Masters Theses

"This investigation involves a photomicrographic study of the segregation resulting from the eutectic solidification characteristics of aluminum-uranium alloys, ranging from 5 to 30 weight percent uranium. The segregation can occur in either of two manners; the first, due to the gravitational forces acting upon the growing particles which nucleate in the melt and the second, due to the mode and rate of heat transfer through the material. It was found that segregation occurred only as the result of the latter factor due to the small volume of the ingot and the rapid rate of heat transfer. The segregation was measured …

Dipole Approximation Of The Solution For An Electrode Configuration In Two-Layer Resistivity Problem, Siew Hung Chan

Masters Theses

"An electrode configuration which consists of a pair of current electrodes, spaced at a unit apart, being kept at a great distance r from a pair of potential electrodes also spaced at a unit apart, has been investigated. Two theoretical apparent resistivity formulae were derived by applying Kelvin's theory of images to the problem of two-layer case. One formula is obtained by the exact method of solution, the other being obtained by considering the pair of current electrodes as a single dipole. Results of numerical calculations show that the greater the spacing r in comparison to the spacing a, …

Electrodeposition Of Antimony From Sulfide Melts, Mahendra N. Rana

Masters Theses

"A study of the current-potential relationships, and the electrodeposition of antimony metal was conducted for fused mixtures of Sb₂S₃-Na₂S, Sb₂S₃-Sb and Sb₂S₃-NaCl-KCl in the temperature range of 700° - 900°C. An attempt was made to determine the mutual solubility of molten antimony and Sb₂S₃-Na₂S melts. The microstructure of deposited metal was studied metallographically. Analysis of phases present in the matte mixture (Sb₂S₃-Na₂S) was made by x-ray diffraction patterns.

All investigations were carried out in …

An Evaluation Of The Resistance Element Method For Measuring Detonation Velocity Of An-Fo Mixtures Confined In Small Diameter Boreholes, William Stewart Breakey

Masters Theses

"Instrumentation and techniques employing a constant current in a 4 ft. length of Nichrome resistance wire embedded in an explosive mixture were developed to measure detonation velocity in small diameter boreholes.

The resistance element technique was evaluated by detonating mixtures in iron and clay pipes, and it was shown that the current in the circuit was not constant. Velocity measurements varied from 8,000 fps to 16,000 fps. Low velocity material provided poor time - voltage traces.

The resistance element method was compared to a pin oscillograph technique, and an explanation was offered for observed differences in velocity. The standard deviation …

A Study Of The Recrystallization And Polygonization Of High Purity Aluminum, Robert Leon Wright

Masters Theses

"Laue back reflection patterns were used along with visual examination in evaluating the characteristics of the annealed structure of high purity (99.99%) aluminum single crystals which had been deformed by elongation. It was found that the glide strain and annealing temperature are primary factors to be considered with respect to the structural changes occurring during annealing.

It was determined that the glide strain must be above a certain critical value to cause recrystallization; below the critical value polygonization will predominate in the annealed structure regardless of the annealing temperature.

The single crystals used in the investigation were grown by the …

Shear Stress Distribution In Haunched Beam Models, Manyu K. Mehta

Masters Theses

"The purpose of this thesis has been to give the distribution of shear stress inside a haunch. A haunch is generally provided to relieve high stress concentrations at the face of the column. However the nature of shear stress distribution inside the haunch is not known.

This stress distribution was determined from a photo- elastic study on a CR-39 model. It is noted that the haunch reduces the stress concentration at the face of the column but at the same time somewhere near the point where the haunch meets the beam there is a high stress concentration.

Shear stress changes …

A Weight Loss Technique For The Determination Of Phase Boundaries, Robert Lee Benner

Masters Theses

"An apparatus has been designed and constructed that would continuously record the weight loss of a sample in a flowing inert atmosphere, at a constant temperature.

A technique has been developed to determine the phase boundaries of a binary phase diagram.

Alloys of the magnesium-nickel, cadmium-antimony, copper-cadmium, copper-zinc, and magnesium-zirconium systems were subjected to investigation to verify the operation and resolve a number of limitations of the equipment.

These investigations disclosed that the apparatus gave the best results with alloys having vapor pressures in the range between 1 and 35 millimeters of mercury"--Abstract, page 2.

Commentary On The 1962 Edition, George Winter

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

An Investigation Of Indeterminate Structures Stressed Beyond The Proportional Limit, Jack B. Joyce

Civil Engineering ETDs

In the structural field the methods of designing have been geared to the development of materials...In a more current appraisal we see steel and concrete being updated still further. Pre-stressed concrete is a common sight in present day construction work and, to a lesser extent, the educated eye sees rigid frames designed to ultimate load criteria. Here again are cases where materials are studied and found to possess characteristics that are adaptable to advance methods. The key to all such improvements is still the realization and utilization of material properties.

New Genera And Species Of Myripristid Fishes, In The Gulf Coast Cenozoic, Known From Otoliths (Pisces, Beryciformes)

School of Mines and Metallurgy Bulletins

Studies of fossil and Recent otoliths (sagittae) supply an important line of evidence, bearing on classification of teleost fishes, supplementary to that of anatomy, osteology, and "phylogenetic" paleoichthyology.

Squirrelfishes ( " Holocentridae" of authors) are generalized forms in which evolutionary divergence of some mag nitude is reflected in unpreservable details of anatomy, inconspicuous skeletal structures, and striking differentiation of the sagittae. Otoliths show the holocentroid complex to consist of one homogeneous unit (l\fyripristidae, elevated) and another more heterogeneous group (Holocentridae, restricted). These lineages have been separate. at least since the middle Eocene.

A revised classification, based on available lines of …

An Acoustic Simulator For Modeling Backscatter Of Electromagnetic Waves, Allen R. Edison

Electrical and Computer Engineering ETDs

Model experiments are commonly employed in situations where a full-scale experiment is uneconomical and where exact theoretical analysis is very difficult. The physical problem is scaled to convenient laboratory dimensions and a means is provided for controlling and measuring the parameters of the experiment. Measurements made in the model system are required to provide information on the time and space variations of functions which describe the real system. When interpreting results it is frequently necessary to consider "scale effects" which arise from certain parameters exerting a different influence in the model than in the real system.

An Investigation Of The Behavior Of Asphalt Stabilized Sand In Triaxial Compression Testing, Joseph P. Callahan

Civil Engineering ETDs

More and more in highway construction, the engineer is faced with the problem of locating satisfactory materials to be used in the construction of highways. This problem has become very critical in the selection of a satisfactory aggregate to be used in many phases of the construction. In large metropolitan areas and in other regions of the United States unblessed with an abundance of this aggregate, it was found that where once there was no shortage of suitable material, the supplies have now been practically exhausted.

A Study Of A Nonlinear Compensation Network In A Feedback Control System, John F. Taylor

Electrical and Computer Engineering ETDs

This paper is a study of the effect of a nonlinear compensation network on the closed-loop response of a feedback control system.

Physical energy dissipation elements, unlike their usual mathematical models, are often nonlinear. An example of such a nonlinear element is the mechanical damper. Since dissipation elements are used in most types of compensation, the problem of nonlinear compensation is an important one.

The study was performed with two goals in mind. The first was to determine the detrimental effects resulting from the insertion of the nonlinear network. The second was to see if any improvement in system performance …

The Design Of A Six Specimen Tensile Fatigue Machine, Charles Mark Percival

Theses and Dissertations

Although metal fatigue has been recognized for many years and during that time many persons have tried to find the explanation for it, there is still not a complete theory concerning this phenomenon. Metal fatigue is one of the major problems the modem designer must face. If the design techniques are to progress as other technological advances are made, it is evident that it will involve a better understanding of metal fatigue.

Design Of An Air Stabilized Plasma Arc, William Robert Clarke

Theses and Dissertations

The plasma-arc generator (see figure 1, 2) has been used for several years as an invaluable ground test facility in which the gas stagnation properties of hypervelocity flight may be reproduced. The plasma is produced by shorting an electric arc between two electrodes; then directing a gas stream through the arc. The gas stream is thus heated to a ''temperature " of forty to fifty thousand degrees Farenheit. At this temperature the gas is in a state of partial ionization termed "plasma". The plasma stream is then constricted and directed by a nozzle into a test chamber and over the …

Analysis Of Radio Wave Propagation Over An Atmospheric Ground Layer By The Ray Tracing Method, Donnelly J. Johnson

Electrical and Computer Engineering ETDs

Previous efforts to analyze radio wave propagation in the troposphere have shown by agreement with experimental results the validity of the use of geometrical optics and the assumption of atmospheric spherical symmetry.

The Irish Plumber And Heating Contractor, July 1961 (Complete Issue)

Building Services Engineering

No abstract provided.

Evaluation Of The Thermal Properties Of Plastic Laminates, Luciano Sedillo

Chemical and Biological Engineering ETDs

To insure the proper application of newly developed materials, it is necessary to evaluate their physical and chemical properties. In the case of plastic laminates for use as heat barrier material, thermal diffusivity is an important property. Thermal diffusivity is the parameter which governs the rate of temperature change through a material. Its value depends upon the chemical composition and the physical structure of the material and its temperature.

An Experimental Study Of The Production Of Metallic Impregnations And Coatings -- A Vacuum Process, Engle D. Southard

Chemical and Biological Engineering ETDs

The purpose of this study undertaken was threefold, (1) to design and construct an experimental vacuum apparatus to produce a metal impregnated or coated material; (2) to study some of the variables which affect the process; then (3) to examine the physical characteristics of the resultant materials. Described herein is the development and operation of a vacuum system capable of producing conditions to permit the evaporation of metals to impregnate and coat various materials. The fundamental principle involved in this process is that a rarified atmosphere reduces the temperature required for metal evaporation and protects the metal vapor from reacting …