Digital Commons Network^™

Deriving Dc Machine Torque By The Principle Of Virtual Work, George Mcpherson

Electrical and Computer Engineering Faculty Research & Creative Works

The purpose of this paper is to fill a gap which exists in the "textbook" theory of dc machines. The paper shows that the usual expression for dc machine torque can be obtained from the direct application of the principle of virtual work to the machine, making the traditional assumptions. The method provides additional benefits in that it demonstrates the reluctance torque which results from the saliency of the field structure and shows that compensating windings have no effect on the torque under the assumed linear conditions. Copyright © 1971 by The Institute of Electrical and Electronics Engineers, Inc.

Electrical Engineering Education In An Industrial Laboratory, J. Derald Morgan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes a unique electrical engineering laboratory course. This laboratory is an example of industry-uni-versity cooperation in engineering education. The organization and operation of the course is outlined and explained. The educational benefits derived from such cooperation between industry and the university are briefly detailed. These benefits are extended to the students, the university, the faculty, and the participating industry. This paper provides the framework and challenge to industry from which other laboratory experiences can be conceived and developed. Copyright © 1971 by The Institute of Electrical and Electronics Engineers, Inc.

A State Assignment Procedure For Asynchronous Sequential Circuits, Gary K. Maki, James H. Tracey

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a new procedure for constructing nonuniversal shared-row internal state assignments for asynchronous sequential circuits. The method consists basically of establishing an initial code with the minimum number of variables required to dis. © 1971, IEEE. All rights reserved.

A Gamma-Level Portable Ring-Core Magnetometer, Stanley V. Marshall

Electrical and Computer Engineering Faculty Research & Creative Works

A four-transistor circuit is described for a battery-operated magnetometer that has 0.1 γ resolution using t-in diameter 4–79 or 6–81 Mo-Permalloy tape cores of 20–40 Mx capacity. The center-tapped drive winding also serves as the sense winding, simplifying the sensor assembly. Some signal-to-noise results are presented to illustrate the fairly wide difference that may exist between cores of the same cross section and to demonstrate the advantage of reducing core area. Copyright © 1971 by The Institute of Electrical and Electronics Engineers, Inc.

Empirical Bayesian Learning, David R. Cunningham, Arthur M. Breipohl

Electrical and Computer Engineering Faculty Research & Creative Works

It is shown that a certain weighted average of the prior distribution and the empirical distribution yields an estimate of the posterior distribution that is consistent with Bayes' theorem. Acomparison of this approach and conventional parametric Bayesian estimation is made for some specific cases. Copyright © 1971 by The Institute of Electrical and Electronics Engineers, Inc.

The Axial Contact Of Finite Elastic Cylinders With Application To Thermal Contact Resistance, Ross Orlo Mcnary

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Predictions of the macroscopic thermal contact resistance have been severely restricted because the macroscopic contact area between finite members could not be determined. A new method of solution to this contact problem in elasticity is developed which is applicable to a wide variety of geometries and boundary conditions. A physical lumped-parameter model is employed from which the finite difference equations in terms of displacement are derived. Calculations using this method indicate that large errors in the prediction of the thermal contact resistance can result if solutions for bodies of infinite extent are employed for finite regions of interest. Especially large …

Charges On Jet Drops Produced By Bursting Bubbles, Robert A. Medrow, B. T. Chao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The sizes and charges of jet drops produced by bursting air bubbles are examined experimentally. The variation in charge for bubble lifetimes of up to 200 sec in NaCl and KCl solutions is reported. Jet drops refer to drops produced by a jet rising from a cavity left in a liquid surface by a bursting bubble; bubble lifetime is the interval during which a bubble is in motion between generation and rupture. With other variables held constant, drop charge shows a characteristic variation of a rise to a maximum followed by a decrease to an asymptotic value, as bubble lifetime …

Diffusion Coefficients Of Ethylene Glycol And Cyclohexanol In The Solvents Ethylene Glycol, Diethylene Glycol, And Propylene Glycol As A Function Of Temperature, Ronald D. Mitchell, James W. Moore, Robert M. Wellek

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Internal Friction Of Ion Exchanged Li₂O•Al₂O₃•2sio₂ Glasses, A. Ismail A. Abdel-Latif

Doctoral Dissertations

"Li₂O•Al₂O₂•2SiO₂ glass fibers were ion-exchanged from 1 to 300 minutes in a sodium nitrate bath at 366ºC. The internal friction was measured along with the lithium and sodium concentration profiles. As sodium progressively replaced lithium, the alkali internal friction peak became smaller while a new peak (mixed alkali peak) appeared and increased in magnitude. These changes in the internal friction are similar to those that occur upon the addition of a second alkali to glasses prepared by conventional melting. The magnitude of both internal friction peaks in ion exchanged glasses was dependent on the overall glass composition. The magnitude of …

Water Conservation Handbook, D J. Carder, G. W. Spencer

Natural resources published reports

This handbook is intended as a practical guide in some of the most common aspects of water conservation in the agricultural areas of Western Australia. It deals mainly with water conserved in dams for stock and domestic purposes on the farm.

the farm. The handbook does not attempt to deal with all aspects of handling and using water for agricultural purposes. This is a vast subject which extends into many fields such as engineering, irrigation and land use.

The guide does, however, touch on some important aspects of good management of agricultural land. It should be read in conjunction with …

Anodic Dissolution Of Beryllium In Anhydrous Media, William Joseph James, Martin E. Straumanis

Chemistry Faculty Research & Creative Works

No abstract provided.

A Stable Explicit Method For Simultaneous Quasi‐Linear Differential Equations, Roy J. Brunson, Robert M. Wellek

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Mass Transfer Inside Liquid Droplets And Gas Bubbles Accompanied By A Second‐Order Chemical Reaction, R. J. Brunson, Robert M. Wellek

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Cylindrical Couette Flow Experiments In The Transition Regime, Darryl J. Alofs, George S. Springer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Density Distributions Were Measured in Rarefied Argon Contained between Two Concentric Cylinders, the Inner One Rotating, the Outer One Stationary. the Experiments Were Performed with a Mach Number Near Unity, based on the Surface Speed and Surface Temperature of the Rotating Cylinder. Particular Attention Was Focused on Obtaining Data in the Slip and Transition Regimes Where the Knudsen Number, Defined as the Ratio of the Mean Free Path to the Gap Size between the Cylinders, Varied from 0.04 to 1.07. the Density Distributions Were Measured by Observing the Gas Luminescence Induced by the Passage of a Narrow Beam of High …

Floating Bubble Configurations, Robert A. Medrow, B. T. Chao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The configurations of bubbles floating at a vapor-liquid interface are investigated both analytically and experimentally. The differential equations governing the shape of a single bubble at rest in a liquid of infinite extent are deduced under the assumption of zero dome thickness, uniform surface tension, and equal gas densities within the bubble and above the interface. These equations show that nondimensional bubble shapes depend upon the value of a single parameter. An analytical solution, valid for small bubbles, is developed and shown to be in good agreement with the general numerical solution. Good agreement with theory is demonstrated for floating …

Clay Cover For Roaded Catchments, J L. Frith, R. A. Nulsen

Journal of the Department of Agriculture, Western Australia, Series 4

RECENT dry years have stimulated interest in improved catchments for farm dams. Although roaded catchments have been installed on many farm dams in Western Australia, most of them fall short of their potential for increasing run-off.

Permeability Scaling In A Numerical Coning Model, V. K. Dutta, Marion D. Arnold

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A method is described for simulating coning into a wellbore using a numerical simulation model. The method allows the wellbore cells to be considerably larger than the actual wellbore. This makes coning studies feasible using an implicit pressure-explicit saturation type model with a reasonable time step. This capability is achieved by scaling the horizontal-vertical permeability ratios to give the proper vertical potential drop.

Perturbation And Sensitivity Analysis Of An Urban Model, Nicola Ann Nelson

Masters Theses

"This work describes a sensitivity analysis of the nine major system variables of the urban model postulated by Dr. Jay W. Forrester in his book Urban Dynamics. This model simulates the growth of a city from a nearly empty land area through a 250 year life cycle. Using small perturbations about the system trajectories, sensitivity matrices were computed at 135 years (growth period) and 240 years (equilibrium). The results show a matrix heavily weighted to give large sensitivity coefficients to the three housing variables, the PH sector being the most sensitive. Each of the housing sectors was analyzed further to …

Laser Interferometric Holography Investigation Of Free Convection About A Vertical Plate Of Non-Uniform Temperature, Richard Kenneth Thomson

Masters Theses

"An experimental investigation was conducted using a holographic interferometer to detect the temperature variation in a free convection boundary layer about a vertical heated plate. The heated plate was non-isothermal and investigations were conducted for four temperature distributions; the maximum plate temperature ranged from 200F to 493F. Photographs were taken of the fringe patterns and boundary layer thickness measurements, as well as temperature measurements, were made. A theoretical model was constructed by applying the integral method to the energy and momentum equations. The experimental values agree quite well with this model. The advantages of the holographic interferometer over other systems …

The Effect Of Diameter On The Film Boiling Behavior Of Liquid Nitrogen, William Joseph Wafer

Masters Theses

"A film boiling heat transfer study was conducted for liquid nitrogen at atmospheric pressure. The heat transfer surfaces used were cylinders with outside diameters of 0.450, 0.650, 0.850, and 1.000 inches. The temperature differences covered were from approximately 150ºF to approximately 600ºF. The data indicate that the heat flux will decrease to a minimum then increase slightly as the diameter of the heat transfer element is increased at constant temperature difference. The heat transfer coefficient is expected to approach a flat plate correlation as the diameter approaches infinity"--Abstract, page ii.

The Thermal Contact Resistance Of Lubricant Films In Vacuum, Garry A. Heizer

Masters Theses

"This paper presents the results of an experimental investigation on the thermal contact resistance of lubricant films and bare interfaces. The apparatus and procedure used in the determination of these resistances are described. Twelve series of tests were performed to evaluate the effects of temperature and contact pressure on the thermal resistance of lubricant films. Variations of thermal contact resistance with temperature and contact pressure for four lubricants and for bare interfaces are presented graphically. The thermal resistances of the four lubricants tested in vacuum conditions: lithium grease, graphite grease, molykote grease, and silicone lubricant, were found to lie in …

Hydrostatic Extrusion Of Tubular Products, John Lester Roth

Masters Theses

"The production of quality tubular products by hydrostatic extrusion has been demonstrated to be a highly satisfactory method. The forming of tubes by the floating mandrel method has been accomplished on mild steel, aluminum alloy, and brass. This thesis describes the method, equipment design and operation, and the results obtained in the hydrostatic tube extrusion. A discussion on the advantages of the use of hydrostatic over conventional extrusion is included. The hydrostatic extrusion system designed for this study is described in detail"--Abstract, page ii.

Two Component Heat Pipe, Surapol Chandsawangbhuvana

Masters Theses

"A two component heat pipe with water and ethanol as the working fluid was investigated at different angles of inclination and various ethanol concentration for two power loads. The heat pipe was 15 inches long and 0.75 inches in diameter with a 100 mesh stainless steel screen wick. The wall and the vapor temperatures were measured at different stations along the length of the heat pipe by copper-constantan thermocouples. The results were used to evaluate an existing model which includes the constraint of thermodynamic phase equilibrium of the solution on the governing equations. Based on the measured pressure and temperature …

The Use Of Scattering Parameters In Amplifier Design, Yousef Neman-Ebrahim

Masters Theses

"The scattering-parameter formulation of an active two-port device is developed from the compensation theorem. The use of scattering parameters in graphical developments of forward operating power gain and tunability is considered in detail. Finally, two design examples show the application of the graphical procedures"--Abstract, page ii.

Density Distribution Measurements In Rarefied Gases Contained Between Parallel Plates At High Temperature Differences, Darryl J. Alofs, Richard C. Flagan, George S. Springer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Density Distributions Were Experimentally Determined in Rarefied Gases at Rest Contained between Two Parallel Plates Maintained at Widely Different Temperatures. the Temperatures of the Hot and Cold Plates Were ∼79°K and ∼294°K, Respectively, Resulting in a Temperature Ratio of About 4:1. Both Helium and Nitrogen Were Used as Test Gases. Particular Attention Was Focused on Obtaining Data in the Temperature Jump and Transition Regimes. the Gas Densities Were Measured by Observing the Luminescence Produced by a High-Energy Electron Beam Traversed between the Plates. in Addition to the Density Measurements, Heat Transfer Measurements Were Also Made in Order to Estimate the …

The Anodic Dissolution Of Tungsten, James W. Johnson, Cheng-Hsiao Wu

Chemical and Biochemical Engineering Faculty Research & Creative Works

The anodic dissolution of tungsten was studied in H₂SO₄-K₂SO₄ solutions (pH = -2 to 2.5) and K₂SO₄-K₂CO₃-KOH solutions (pH = 11.5 to 14.5) at 25 C. Faradaic efficiency studies in basic solutions showed the metal to be oxidized to the +6 state. In acid solutions, a thick protective film of yellow WO₃ was formed. Polarization curves possessed linear Tafel regions (slope ~ 2.3 RT/F) at potentials slightly more positive than the rest potentials. An anodic dissolution mechanism is proposed which involves a surface film …

A Magnetic Aftereffect In Dilute H.C.P. Co-C Alloys, J. R. Keiser, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

A magnetic Dis accommodation in dilute h.c.p. Co-C alloys has been observed around 90°C. The thermally activated process giving rise to the Dis accommodation is characterized by an activation energy of 26 kcal mole-1 and an attack frequency on the order of 10+13 sec-1. An application of the selection rules shows that the Dis accommodation cannot be caused by the redistribution of tetrahedral or octahedral interstitials or any nearest neighbor interstitial pairs as long as the defects interact linearly with the internal magnetic field. © 1971.

On The Activation Entropy Of Interstitial Diffusion In B.C.C. Iron, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Mixed‐Cation Effect In Silver Borate Glasses, E. N. Boulos, N. J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

The Anodic Dissolution Reaction Of Insb: Etch Patterns, Electron Number, Anodic Disintegration, And Film Formation, Martin E. Straumanis, Lih Da Hu

Materials Science and Engineering Faculty Research & Creative Works

The etching behavior of the inverse {111} planes of undoped, semiconducting, n-type, InSb single crystals was explored. Depending upon the etchant, including anodic dissolution, various etch patterns were obtained on the inverse planes. In general, the etch pits on the In{111} plane were round, and the face was shiny, whereas the face of the inverse plane was dark and rough. The rates of dissolution in the electrolytes used were very low, especially in absence of oxidizers. The components dissolve as In3+ and Sb3 +. At current densities above 40 or 60 mA cm-2 (on Sb{111} or In{111}), growth of a …