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The Effects Of Surface Flaw Density And Configuration On Fracture Stresses Of A Triaxial Porcelain., William H. Daniels

Masters Theses

"The fracture behavior of a model brittle solid containing artificial surface flaws was studied. An industrial ceramic porcelain body was employed as the model brittle material. Sample groups of specimens containing 6, 11, 24, 49,. and 90 sharp surface notches uniformly distributed over a four inch length were broken under pure bending. The fracture data we-re compared to those of an identically treated control group containing no artificial flaws.

The mean strengths of the two groups of lowest flaw density were identical, both being significantly less than that for the control group. Further increases in flaw density resulted in increased …

Influence Of Quartz Particle Size And Concentration On The Fracture Stresses Of Triaxial Alumina Porcelain., John David Weyand

Masters Theses

"Quartz particles were introduced into a typical triaxial alumina porcelain. Three levels of particle size and three levels of concentration were studied. The strength sample sizes were large. A diametral- compression loading method was used for strength testing. It was found that the porcelain strength decreased with increasing grain size and concentration of quartz particles. A linear relationship existed between log quartz concentration and mean fracture stress"--Abstract, p. ii

Application Of An Orifice Meter To Fan Testing., J. F. T. Agapito

Masters Theses

"In this investigation the application of an orifice meter to fan testing was studied and evaluated. An orifice meter was designed and was installed in a centrifugal fan duct. Measurements were checked and compared with those of a standard pitot-tube traverse and were found to be in very close agreement. It is suggested that a meter of this type could easily be adapted not only to laboratory work but also to field tests"--Abstract, p. ii

Solid Solubility Of Sodium Oxide In Tricalcium Aluminate, Joel A. Conwicke

Masters Theses

"The tie line connecting the compounds 3CaO·Al₂O₃ and Na₂O·8CaO·3Al₂O₃ in the ternary system CaO-Al₂O₃-Na₂O was studied at 1250° Celsius.

It was determined that Na₂O can exist in crystalline solution with 3CaO·Al₂O₃ in percentages of about 2.3% or less without any apparent change in the structure of 3CaO·Al₂O₃. X-ray diffraction peaks in the back-reflection region shifted to lower d-spacing values on increasing Na₂O contents.

At a Na₂O content of about 2.7%, each major x-ray …

The Effect Of Surface Roughness, Cure Pressure, And Temperature Level On The Thermal Resistance Of Bonds And Contacts, David Leo Schwaller

Masters Theses

"This investigation was conducted to determine the thermal effect of temperature level, surface roughness, and curing pressure on bars and bonded interfaces.

The equipment used in this investigation is shown in Fig. 1 and Fig. 2. The four specimens used, cylindrical aluminum alloy bars, were cut radially at their midpoints and faced on a lathe. Heat was supplied by an electrical resistance heating element and an ice bath was used to conduct heat from the alloy specimen. A heat shield was used to insure one dimensional heat flow. Spacers were placed in the insulation at the top, the interface, and …

The Effect Of The Static Compaction On The Mechanical And Physical Properties Of Asphalt Concrete Hot-Mixes, Abdel-Gawad A. Bahgat

Masters Theses

"The objective of this investigation was to study the effect of the static compaction effort upon the physical and mechanical properties of asphalt concrete hot mixes. To study the effect of the static compaction upon the physical properties of the asphalt mixes, six mixes were prepared using hard, well graded crushed limestone as an aggregate, blended with an 85-100 penetration grade asphalt cement. The control mix was prepared and tested in accordance with the Marshall method for mix design. The other five mixes were prepared and tested using the same procedures of Marshall except for compaction, where five different static …

Determination Of Transient Temperature Stresses In Plates, Teh Yu Hu

Masters Theses

“The purpose of this thesis is to determine the transient temperature stresses in two-dimensional plate structures restrained against rotation at the ends but not restrained against elongation. In this investigation, only one-dimensional heat flow is considered. The heat flow is first treated as a problem in pure conduction and then the effects of convection through a boundary layer are considered.

The differential equation of transient heat conduction is solved by Fourier series and Duhamel’s theorem, and a graphical method of solution for temperatures in terms of dimensionless parameters is presented.

Solution of this problem is valid for a semi-infinite plate …

A Theoretical And Experimental Study Of The Stress Distribution In An Infinite Plane Shrink-Fitted On Four Circular Elastic Pins, Charles H. White

Masters Theses

"The purpose of this study is to show a general method of solution for multiple inclusions in an infinite plane. The shrink-fitting of an infinite plane upon the inclusions, or pins, will be simulated by force-fitting the pins into a large sheet of birefringent material, to obtain an experimental verification of the analytical solution.

The problem to be approached is that of four circular elastic pins shrink-fitted in an infinite plane. The method of superposition will be used, and the stresses at any point in the plane found with respect to a common origin of coordinates. It will first be …

A Study Of Plane And Spherical Compressional Waves In A Voigt Viscoelastic Medium, Gerald B. Rupert

Doctoral Dissertations

"In investigating the behavior of waves traveling through cohesive solids, two assumptions are usually made: that the propagating medium is either elastic or viscoelastic, and that the wave is either planar or spherical in form. For small distances from the source of the disturbance the medium can be considered elastic and the wave spherical rather than planar. The assumption of elasticity allows considerable simplification of the mathematical analysis, and assuming a spherical wave form is an acceptable approximation if the initial disturbance is essentially a point source and the propagating medium is nearly homogeneous. However, for large distances from the …

A Thermodynamic Study Of The Zirconium-Sulfur, Titanium-Sulfur And Hafnium-Sulfur Systems In The Disulfide-Trisulfide Region, Norbert Achilles Vermaut

Doctoral Dissertations

"A static method was used to study the equilibria which exist between the higher sulfides of zirconium and sulfur at temperatures from 700° to 1000 °C. Both disulfide and trisulfide have been identified by chemical analysis and X-ray diffraction. There exists a two-phase region of 'ZrS₂' and 'ZrS₃'. The composition limit of the homogeneous disulfide phase appears to exist between ZrS_1.90 and ZrS_2.00. The lower composition limit of the homogeneous region of the trisulfide phase was established as ZrS_2.75.

An experimental method of Blitz and co-workers, i.e., the use of evacuated …

A Study Of Turbulent Mass Transfer In A Wetted-Wall Column, David William Bunch

Doctoral Dissertations

"The field of mass transfer is one of great interest to the chemical engineer. An understanding of this field is vital in the design of many types of chemical processing equipment, particularly in the areas of distillation, extraction, absorption, adsorption, and reactor analysis and design.

However, much of the knowledge in this area at the present time is in the form of empirical relationships, and the basic theory is still not well delineated. This lack of understanding leads to expensive and over-sized or under-sized equipment.

A particular area within this field which needs additional investigation is the theory of mass …

Mechanism Of Siliconizing Of Molybdenum And Tantalum By Vapor Deposition, Gordon Pu Kong Chu

Doctoral Dissertations

"Molybdenum and tantalum were siliconized in an enclosed system by the hydrogen reduction of silicon tetrachloride with induction heating between 900°C and 1450°C.

The siliconizing process was primarily influenced by the gaseous composition, temperature, time, molar flow ratio (SiCl₄/H₂), geometrical shape and ionization charges. The rate of siliconizing, measured as the weight gain by the fused quartz helix balance, generally follows a parabolic law, y = k t^1/2, where y = weight gain, t = time, and k = rate constant. The activation energy is estimated at 21.6 k cal/mole for siliconizing of molybdenum. …

A Study Of The Eddy Diffusivity In Turbulent Heat Transfer, Frank Fu-Kun Tao

Doctoral Dissertations

"The purpose of this investigation was to determine the eddy thermal diffusivity values as a function of radial position at various Reynolds numbers for a fluid flowing turbulently in a pipe. The ratios of the eddy thermal diffusivity and the eddy viscosity were also investigated.

A vertical column of copper tube two inches in diameter was constructed which consisted of an entrance section for the development of the velocity profile and a heating section for the development of the temperature distribution. The heating section was jacketed and maintained at a constant wall temperature at about 103 ° F by the …

Lattice Parameters, Thermal Expansion Coefficients, Densities, And Imperfections In Silver And In The Alpha-Phase Of The Silver-Indium System, Samir Moustafa Riad

Doctoral Dissertations

“An investigation of structure insensitive properties (lattice parameters, thermal expansion coefficients, densities, and imperfections) of silver and the α-phase of the silver-indium system was suggested by the desirable uses for silver and its indium alloys.

Both silver and indium used were 99.999 per cent pure. The silver-indium alloys were prepared by melting both metals inside evacuated and sealed fused quartz tubes. The solidified alloys were annealed and then examined by X-ray diffraction for homogeneity.

This experimental work is divided into three main parts:-

I. X-ray diffraction investigation to determine the solid solubility limit of the Ag-In α-phase at 25° C, …

Investigation Of Inoculant Effect On Cast Iron, Darrell W. Donis

Masters Theses

"An assumption was made that extensive holding time of an inoculated gray iron melt would result in a loss of physical properties of castings poured from this melt. This theory was examined in both a literature search and by testing and conclusions drawn from these findings are presented and discussed. Although there is a great deal of data available which discusses inoculants and their effects, very little mention is made of the effect of holding time in any of this material. The results indicate that holding time is of considerable importance when dealing with inoculated iron, and that calcium silicon …

An Investigation Of The Adaptability Of The Linvill Model For Transistor Synthesis, John A. Reagan

Masters Theses

"The Linvill transistor model may be used for transistor synthesis if the model accurately approximates transistor response and may be readily simulated on an analog computer. Experiments were performed on a transistor to determine the Linvill model parameters. The transistor's large-signal transient response was investigated by pulsing the emitter with a current that drove the transistor from the active region of operation into saturation. The same problem solved experimentally was then solved analytically by replacing the transistor with the Linvill model. The experiment was then simulated on an analog computer by using the equations that govern the Linvill model's response. …

A Laboratory Study Of The Effect Of Wettability Of Residual Oil Saturation In Artificial Cores., Socrates Nicholas Potamianos

Masters Theses

"In the past much emphasis has been placed on various studies of reservoir rock and fluid surface properties and their relation to the different oil recovery processes. Several laboratory methods (1, 2, 3) ^l/have been used by different investigators to obtain a more fundamental understanding of the many factors which have an influence on the oil recovery from reservoir rocks"--Introduction, p. 1

Design, Construction And Characterization Of A 10-Liter Batch Pilot Plant Fermentor., Sylvester Ogden

Masters Theses

"A 10-liter batch type pilot plant fermentor has been designed and constructed. The design incorporated most of the desirable features of previous designs reported in the literature.

The stainless steel fermentor has a multi-speed agitator and aeration rates as high as 15 cubic feet per hour. Temperature indicating, temperature controlling, pH measuring, and automatic foam controlling systems are included in the design.

Sulfite oxidation rates have been determined for the unit at 15 operating conditions. A maximum sulfite oxidation rate of 1060 millimoles of oxygen per liter per hour has been obtained.

Fermentation using a Torulopsis utilis yeast culture has …

Investigation Of Zero Sidesway For Rigid Frames, Dolatray S. Mehta

Masters Theses

"This study was made to determine the location of a point at which a vertical load may be applied to a rigid frame structure and produce zero sidesway, the so called zero sidesway axis. For concentrated loads equations have been derived for zero sidesway. For uniform and triangular loads graphs showing zero sidesway for various ratios of column and beam stiffnesses and height ratios have been plotted"--Abstract, page ii.

The Submerged Culture Of Thiobacillus Thio-Oxidans In A Pilot Scale Fermentor, Edward Hibbert Crum

Masters Theses

"A strain of Thiobaci.llus thiooxidans was isolated from a West Virginia coal mine drainage. This strain was characterized by its production of sulfuric acid in shake flasks. The strain was also compared with a pure culture of h thiooxidans obtained from the American Type Culture Collection (ATCC number 8085).

The strain was grown in submerged culture in a 16-liter pilot scale fermenter. Two aeration systems, air and air enriched with carbon dioxide, were examined. The air enriched with carbon dioxide gave a much more rapid growth rate. The culture reached the mid-log phase of growth after 80 hours of incubation …

Ignition Time Lag: A Measure Of Explosive Energy Release, Paul H. Rydlund

Masters Theses

"By means of the resistance-element, or probe-wire, detonation-velocity measurement technique, explosive reactions from various blasting agents were studied. To reduce the number of variables, only standard AN-FO 94/6 mixtures were used, as are commonly employed today in constructions and mining operations. Accuracy of the data obtained was excellent, and the method proved itself not only relatively simple to operate but versatile in providing considerable information under many testing conditions. Studies of test records revealed the presence of a time-lag frequently occuring [sic] after primer detonation. Environmental factors such as confinement, charge diameter, primer size and energy content, and surface coatings …

The Design, Construction, And Operation Of A Conducting Field Analog Computer., Richard T. Johnson

Masters Theses

"The purpose of this investigation is to design and construct a simple conducting field analog to solve problems described by the two-dimensional Poisson or Laplace equations. Decisions concerning choice of conducting media, construction of problem models, and design and construction of a specialized power supply with instrumentation were based on the results of previous experiments. Several problems are solved using the designed apparatus. Partial solutions to these problems are displayed in graphical form.

The greatest deviation of the experimental results from iterative values was consistently less than 8%. In most cases the deviation was less than 6%. The console arrangement …

A Study Of Certain Atmospheric Effects On Radar Accuracy, Kenneth R. Swimm

Electrical and Computer Engineering ETDs

Along with other factors, accurate radar target location is dependent upon a knowledge of the electromagnetic propagation path. The propagation path is a function of the characteristics of the medium through which the signal travels. Advances in the resolution capabilities of modern electronic tracking equipment have led to requirements for more accurate prediction of atmospheric refraction characteristics. The inherent error of the equipment is, in many cases, less than the error introduced by the atmospheric refractive effects. After corrections to observed launch angle and target range have been made on the basis of atmospheric refraction information, residual errors in range …

The Development Of A Temperature Probe And Temperature Survey Of The Interaction Of An Oblique Shock Wave And A Turbulant Boundary Layer, Donald M. Yano

Mechanical Engineering ETDs

The purpose of this investigation was to develop a miniature air temperature probe and to measure temperatures in the interaction region of an oblique shock wave and a turbulent boundary layer.

The Magnetocardiogram A New Approach To The Fields Surrounding The Heart, R. A. Stratbucker, C. M. Hyde, S. E. Wixon

Department of Electrical and Computer Engineering: Faculty Publications

Experiments have been conducted which reveal the existence of a detectable magnetic field associated with cardiac electrical activity. The relationship between the magnetic record and the electrocardiogram has been explored and it is shown that under certain conditions of axis orientation the voltage induced into a toroidal sensing element around the heart has the form of the first time derivative of the electrocardiogram. A formula based on Maxwell's equations has been developed to relate these two phenomona.

Analysis Of The Transient Response Of A Flat Rotating Disk By Generalized Transforms, Kenneth Wayne Chase

Theses and Dissertations

The object of this thesis was to lay a foundation for a comprehensive study of the dynamic response of rotating members. This initial phase of the study includes a theoretical investigation and proposes experimental techniques for the determination of the stresses and strains in a thin, rotating disk with a concentric hole, subjected to transient shaft inputs. There are many practical applications of this problem including computor memory storage disks, turbine rotors, grinding wheels, saw blades, gears, optical reflectors, and solar sails for space vehicles.

A Five Dimensional Field Theory., Scott Holzhauser

Electrical and Computer Engineering ETDs

Several authors in the past have utilized the five dimensional manifold to accomplish their ends, as the next few sections explain. The ends are frequently different, however, Corben1,2 relates his fifth dimensional variables to rest quantities, such as the "rest mass density" and "rest charge density." Flint3,4,5 uses x as an unobservable 5 cyclic coordinate, and Ingraham6 interprets x as a "parameter of finiteness" that keeps finite the usual field quantities.

Analysis Of Steady State Heat Flux Measurement By The Initial Slope Technique, Charles Earl Cartmill

Theses and Dissertations

The impulse technique is progressively being developed for determining the steady state rate of heat transfer systems involving exponential temperature-time histories. A pulse thermocouple system has been utilized in such a technique having a steady state response time on the order of one time constant of the thermocouple used. When an impulse thermocouple system is not used, the required time in obtaining the steady state value is on the order of five time constants or the time required to reach steady state.

An Acoustic Antenna With A Hollow Searchlight Pattern, Thurlow W.H. Caffey

Electrical and Computer Engineering ETDs

Economy, repeatibility, and convenience make it desirable to model a radar system by means of an acoustic system. The modeling is based upon the fact that, in a lossless medium, both EM-waves and acoustic waves obey a traveling wave equation of the same form. Furthermore, the field components of a plane wave in each system are related to each other by equations of the same form.

Adaptive Communication Systems, Arthur M. Breipohl

Electrical and Computer Engineering ETDs

The purpose of this study is to investigate an "adaptive" communication system in order to characterize the elements of adaptation. Although the term "adaptive" does not have a universally accepted meaning in the technical literature, it is usually applied to systems that have a significant ability to adjust their performance automatically over relatively wide variations in environment. In this sense almost any feedback system is adaptive, but the term is usually reserved for the more exotic systems which appear to make a deliberate effort to monitor the environment and then adjust their performance. Man is usually taken as the primary …