Engineering Commons^™

Electromagnetic Scattering From A Statistically Rough Spherical Surface With Shadowing, James Albert Doran

Electrical and Computer Engineering ETDs

Significant errors may be introduced into the theoretical calculation of scattered fields from a roughened sphere by the use of erroneously derived shadowing probabilities. These shadowing probabilities, of recent appearance in the literature, had been derived using an infinite plane as the mean surface. This paper undertakes the derivation of shadowing probabilities using a spherical mean surface. Although closed form expressions could not be obtained, computer evaluation of a "correction factor" showed that the errors incurred through use of the infinite plane probabilities (rather than the spherical surface) are insignificant. The class of rough surfaces considered was with a gaussian …

Measurement Of Deformations An A Large Displacement Gradient Field, Lowell P. Martin

Mechanical Engineering ETDs

A summary of the general kinematical theory of finite deformations is presented together with analyses of the specific deformations of sim­ple shear, bending of a block and bending of an initially curved cuboid.

The moiré fringe equations for large homogeneous deformation are developed. The extension to the nonhomogeneous case is presented and specific analyses are given for the deformations noted above. The moiré theory is combined with the results of the large deformation analyses.

Theoretical results are verified by the study of geometrically produced moiré patterns, and by actual experiments conducted on syn­thetic rubber specimens. The experiments included the deformations …

Coagulation In Waste Water Treatment, Garret P. Westerhoff

Theses

This paper emphasizes a practical approach to the coagulation of domestic waste water. A portion of the paper is a synopsis of current published literature on the subject. Laboratory studies on the coagulation of raw domestic waste waters were conducted to provide the basis of a practical procedure for the evaluation and design of a coagulation process. Studies included the development of a relationship between the B.O.D. and the soluble and solids portion of two waste tests. The jar test was used for the studies on the coagulation process. The final section of the paper outlines the chemical cost factors …

Fault Protection With A Digital Computer, George D. Rockefeller

Theses

A fundamental basis has been developed for the use of a time-shared stored-program digital computer to perform many of the electrical power-system protective-relay functions in a substation. Logic operations are given to detect a fault, locate it and initiate the opening of the appropriate circuit breakers, whether the fault is in the station or on lines radiating from the station.

The instantaneous value of the station voltages and currents are sampled at a 0.5 ms rate, converted to digital form and stored for computer main-frame use. Operating times are compatible with the 25 ms breaker trip capability of modern two-cycle …

Liquid Vapor Equilibrium In Nucleate And Film Boiling, Walter Henry Rothaug

Theses

Liquid vapor equilibrium data were obtained for several solutions and azeotropes under both nucleate and film boiling. The data were invariant between the two boiling regimes indicating that both nucleate and film boiling are equilibrium vaporizations rather than either diffusional or bulk vaporizations. Boiling heat transfer versus temperature data were taken in nucleate and film boiling for the solutions and azeotropes and for several pure liquids. The critical heat flux for methyl alcohol-benzene solutions rose sharply at first and then more moderately with increasing alcohol concentration. The critical heat flux was pratically constant regardless of concentration in ethyl alcohol-benzene solutions. …

The Effect Of Internal Combustion Engine Operation Upon The Viscometric Properties Of Polymer Thickened Multi-Viscosity Crankcase Oils, William Charles Philcox

Theses

The effects of engine mileage upon the viscometric properties of seven different brands of multi-viscosity engine oils were examined by subjecting each brand of oil to an average of 1500 miles of service in the crankcases of different passenger cars.

Oil samples were taken every 500 miles after the oil was put in the crankcase. The control oil sample was taken from a can of oil at the time the oil was put in the engine.

The viscosity indices and kinematic viscosities at 100° F and 210° F were calculated for each sample of oil. The percent change in viscosity …

Reliability Considerations For Communication Satellites, Frank Polizzi

Theses

A detailed program covering all phases of reliability for a communication satellite was presented. In long mission programs such as this one, reliability is the prime consideration in assuring a successful accomplishment of the stringent goals set forth. Reliability principles and methods were incorporated in delineating each major task in the program. These principles and methods not only aided the reliability personnel in performing their duties better, but also assisted the design group, manufacturing personnel, and the testing and evaluation group in performing their jobs efficiently by being aware and knowledgeable of reliability engineering.

Various reliability disciplines were imposed, as …

The Effects Of Air-Water Two Phase Flow On The Performance Of A Centrifugal Pump, Karnig Ekizian

Theses

This study investigates the performance of a 1-inch long 4-vane open impeller centrifugal pump under two phase flow conditions. The paddle wheel pump, as branded by its manufacturer the Worthington Corporation, had a specific speed of 3400 (based on gallons per minute, feet of water and revolutions per minute) corresponding to a 7-inch impeller diameter. A 1/8-inch perforated steel pipe carried the compressed air to within four inches of the impeller eye where the air was injected into the water stream (See figures 18 and 20).

The three variable inputs were, water flow rate, pump speed and air flow rate. …

A Study Of The Properties Of The Biconical Antenna, Kurt Frank Hafner Jr.

Theses

Expressions are found for the fields produced by TM and TEM modes along a finitely conducting biconical antenna. Expressions are also found for the TM and TEM fileds along a biconical antenna having a lossy dielectric coating. It is shown that the antenna losses produce an anntenuation of the the fields along the antenna. It is found that because there is a dispersion of the fields along the biconical antenna, the attenuation produced by the losses is, in genaral, not characterized by simple exponential.

A solution is obtained for the fields of the TEM wave along a biconical antenna coated …

Magnetic Control Of Carrier Concentration In Semiconductors, S. Lee Hight

Electrical and Computer Engineering ETDs

Magnetic control of carrier lifetime in semiconductors has been examined from a standpoint of applying this phenomenon to low-voltage, high-current switching devices. The continuity equation is extensively examined for intrinsic semiconductors, and limits are derived on the magnitude of the switching effects in terms of material parameters. Experiments have been conducted on undoped indium antimonide which tend to verify these limits. A cursory examination is made of the control of the lifetime of injected carriers. The indications are that this effect may be useful in a wider range of materials than the effect in intrinsic semiconductors.

Response Of A Nonlinear System To Random Vibration, James Darrell Gibson

Mechanical Engineering ETDs

Response statistics are obtained for a nonlinear, single-degree-of-freedom system subjected to a Gaussian, white noise random excitation. The system has nonlinear damping as well as nonlinear stiffness. The stationary joint probability density function is obtained as the numerical solution to the appropriate Fokker-Planck equation for the nonlinear system being considered. The first order probability density function, the mean square displacement, the average frequency of the response, and the average number of crossings of an arbitrary displacement level are subsequently obtained. These response statistics are compared with those obtained experimentally by simulating the nonlinear system under investigation on a solid state …

Stress Fluid In The Vicinity Of A Crack, Alfred S. Arcache

Mechanical Engineering ETDs

The purpose of this investigation was to apply the logarithmic hypothesis of the plane elastic dislocation theory to approximate a plane fracture problem. The region of study is essentially elastic except for a very small region in the neighborhood of the crack which is at some undefined plastic state. The model is a large, thin plate, tensile specimen bounded at the interior by a circular hole from which two stable natural cracks are originated. The experimental model was developed by Ju and Shafer, who also obtained the dislocation function along the crack used in the analysis.

The present fracture analysis …

Low-Cycle Fatigue Damage In Structures Subjected To Earthquake Excitation., Iyadurai Kasiraj

Civil Engineering ETDs

The object of this investigation is to ascertain the possibility of having low-cycle fatigue failure of structures resulting from earthquake loads. In addition, a comparison is made between criteria of failure for maximum displacement and low-cycle fatigue.

The relationship between applied load, deflection and maximum strain in a shear type simple frame with rectangular columns have been analyzed for reversals of loadings. Two interrelated hysteresis loops, namely load-maximum strain curve and deflection-maximum strain curve, are proposed to give the upper-bound safety of the structure having columns with an average wide-flange (WF) section. These hysteresis loops are utilized for finding the …

Trends Of Suspended Sediments In The Upper Rio Grande Basin In New Mexico., Vernon W. Norman

Civil Engineering ETDs

Man has been troubled by the sediment in streams for many thousands of years. Any information toward understanding the nature of this sediment should benefit man in his endeavor to cope with it. Available information was used to determine if trends in the annual quantities of suspended sediment exist in the Upper Rio Grande Bas in in New Mexico. The study revealed that trends do exist and quantitative values were determined for the different trend periods. An effort was made to determine the most probable cause or causes for the changes that occurred in the trends. Eighteen years of suspended …

A Technique For Determining Transistor Spall Thresholds., Herbert L. Floyd Jr.

Electrical and Computer Engineering ETDs

ABSTRACT

The purpose of the work described in this report was to develop a technique for determining the mechanical robustness of small electronic components when subjected to short duration stress waves. Techniques employed by other experimenters., which include flyer­plate impaction and pulsed-electron deposition., are difficult to control and to analyze. The procedure described herein overcomes these difficulties by restricting the variables that control accuracy to those which can be precisely measured.

The wave equation was derived and solved for deformable bodies subjected to unidimensional strain. In addition to providing insight into the dependence of high-tensile stress es on stress -wave …

Investigation Of Implicit Methods For Solution Of The Fourier Equation, Kjell Steinar Gundersen

Theses and Dissertations

In recent years there has been an extensive development of finite difference techniques for solution of the transient heat conduction equation due to the availability of high-speed digital computers. It is the purpose of this paper to investigate and compare several implicit methods for the solution of the Fourier equation with regards to truncation error, round-off error and computer time which probably are among the most important factors to be considered in choosing a method.

A Study Of Free Surface And Viscous Effects On Simulated Rough Open Channel Beds, Julian B. Andersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An experiment was designed to eliminate the free surface from simulated naturally roughened open channel beds from which results were compared to data with a free surface from another study. All other pertinent variables were held constant. From this comparison, a relationship was established for the additional energy loss due to the presence of a free surface in the flow over these channel beds.
P = 0.23 - 0.28 D/D₂₅
where P is the proportion that the channel conductance coefficient (C/g^1/2) is reduced due to presence of a free surface, D is the flow depth, K_{25 …}

Irrigation Demand In The Utah Lake Drainage Area The Role Of Irrigation Efficiency, Hiro Mizue

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of irrigation efficiency upon the water demand for agricultural purposes in the Utah Lake drainage area has been evaluated in this study . Irrigation demand is the quantity of water at the supply source necessary to satisfy crop water requirements, taking into account irrigation efficiency.

The Utah Lake drainage area was divided into hydrologic subareas and districts to facilitate analysis. The demand, surplus, and deficit quantities for each area was determined. The computations were made using constant mean quantities. Within a given area, the diverted water was assumed to be applied uniformly to satisfy agricultural crop demands, and …

Study Of Sheltered Evaporation In Colombia, Guillermo Pardo-Bonilla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Equations, tables, and graphs for estimating evaporation from sheltered evaporimeters were developed, based on data from 20 stations in Colombia.

Computer programs and plottings were the basic tools to work out the equations. The form of the simplified final equation is

Ev = kC_VPDC_T

in which

• Ev is the evaporation in millimeters per day
• K is a constant
• C_VPD is the vapor pressure deficit coefficient
• C_T is the temperature coefficient

Statistical parameters were determined to compare the measured evaporation with the Christiansen-Guillen formula and the newly developed formulas.

An Experimental Study Of The Effects Of Welding On Cold-Worked And On Heat-Treated Steels As They Correlate To Tempering And Jominy Data, Kiran Patwari

Theses and Dissertations

Since Bernandos of Russia in 1887 applied an electric arc to weld metals, welding has become an important method of fabrication in industry. The ever increasing use of welding on a still widening variety of materials demands m ore and m ore understanding of the basic mechanisms of welding.

Transition From Laminar To Turbulent Flow For Dilute Guar Gum Solutions, Martin L. Palmer

Theses and Dissertations

Solutions of many natural and synthetic polymers have been found to reduce turbulent friction losses in flow through pipes. The basic mechanism causing these reductions is not entirely understood although two general theories have been advanced.

Design Criteria For Usu Stilling Basin Pipe Flow To Open Channels, Chi-Yuan Wei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Criterion have been developed in this study for designing a stilling basin to serve as a transition from pipe flow to open channel flow. The purpose of the structure is to prevent erosion in an open channel. The unsteadiness, or smoothness, of the water surface in the model basin was used as the criterion for evaluating the effectiveness of the structure for energy dissipation.

The introduction of a short-pipe energy dissipater in the stilling basin has proven effective in dissipating energy. The stilling basin was designed for a fully submerged pipe outlet. The inflow pipe and the dissipator pipe were …

Study Of Tensile Stress Versus Strain Characteristics Of Vinyl Plastic At Various Temperatures As A Function Of Strain Rate, Jitendra T. Parikh

Theses and Dissertations

The purpose of this thesis was to study the tensile-stress versus strain characteristics of vinyl plastic at various temperatures as a function of strain rate.

A Similarity Model For Flow In A Turbulent Boundary Layer, Earl Clark Lemmon

Theses and Dissertations

One of the basic goals in engineering is to generate models which will provide a means for analytically predicting observed phenomenon. Such a model is often modified several times to obtain better results. The purpose of this study was to generate a model for an equilibrium turbulent boundary layer for steady flow over a flat plate and compare the results obtained by using the model with experimental data. Part of the objective was to also suggest ways in which the model could be modified to obtain better results.

Developing Turbulent Flow In An Annulus, Dwight H. Kelly

Theses and Dissertations

Turbulent flows are encountered in nearly every case where fluid motion is involved. Since turbulent flow through relatively short annular sections occurs frequently in practical applications, e.g., flow through heat exchangers, axial flow turbomachinery and jet aircraft engines, there is a need for detailed information on this subject.

Streamflow Forecasting For The Logan And Blacksmith Fork Rivers In Northern Utah, Kenneth A. Mangelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Accurate streamflow forecasts have been recognized as being important by water users and others whose occupations and pursuits depend upon the supply of water from snow fed streams.

The streamflow forecasting equations for the important predictive periods, in particular the April through September and the May through September total flows, were developed in this study for both the Logan and Blacksmith Fork Rivers.

Multiple linear regress ion was used as a mathematical model in determining the streamflow forecasting equations. A correlation analysis was used to determine the importance of the variables used in the mathematical model. The results of this …

Design Of An Automatically Controlled-Feed, Constant Current Arc Generating Machine For Consumable Electrodes, Dhansukh J. Chauhan

Theses and Dissertations

Good welding research requires accurate control of the variables involved,to achieve consistent results. The variables involved in arc welding are of the dependent and independent type. Control of the independent variables such as arc current, arc voltage and welding velocity is necessary to control the independent variables such as penetration, electrode consumption rate, etc. The purpose of this thesis was to design, develop and test an automatic welding machine which controlled the above variables within the limits required for welding research.

Design Of An Apparatus For Study Of Stress Versus Strain As A Function Of Strain Rate In Plastics, Ashok B. Choksi

Theses and Dissertations

As new materials are developed, it is essential to study their mechanical properties experimentally. It is easy to find properties like ultimate strength, yield strength, hardness, etc., using standard techniques. It is not possible to observe the tensile behavior of materials at high strain rates using standard equipment. Plastics are often subjected to tensile loads at various rates of loading, such as when they are used to absorb impact.

The Enrichment Of Hydro-Carbon Fuel By Aluminum Powder In An Open-Hearth Furnace, Rick Sung-Tao Lee

Theses and Dissertations

The objective of this thesis was to study theoretically the enrichment of hydrocarbon fuels with aluminum powder for an open-hearth furnace.

Electric Arc Welding Of Gray Cast Iron Without Preheating, Ramon Prestwich

Theses and Dissertations

Cast irons are iron-carbon alloys with greater than 1.7% carbon. Although white, malleable and ductile cast irons are used extensively for casting work, this study is concerned with only the gray cast irons.