Engineering Commons^™

Analytical Study Of Heat Conduction And Thermal Stress In Solids With Pressure Dependent Contact Resistance, Dhruvkumar S. Patel

Theses and Dissertations

In the usual thermal stress analysis of a body, the stresses are found for a predetermined temperature distribution. In problems involving composite materials, thermal contact resistance between materials can significantly affect the temperature distribution. The contact resistance is normally a function of the contact pressure and thermally induced stresses can affect the temperature distribution. Thus in composite bodies the thermal stress problem and the heat transfer problem may be coupled and require a simultaneous solution of both problems.

Water Injection In An Automobile Gas Turbine Combustion System, Billy Ray Jackson

Theses and Dissertations

"GENTLEMEN, JUNK YOUR ENGINES!" This title of a recent periodical article [1]* catches some of the expectation for the wedding of the Automobile and the Gas Turbine, The nuptials cannot be completed though, unless two problems are overcome: 1) high fuel consumption, and 2) high operating temperature. The first problem is solvable by the use of heat regeneration and much work has been done in this area [2][3] [4]. The solution of the second problem of high operating temperature was the basis for this thesis. The method of solution was by water injection into the combustion gases prior to entrance …

Optimization Of Physical Properties Of Hydraulic Cushion Cells For Vehicle Impact Restraint, William Evans Hughes

Theses and Dissertations

In recent years, the United States has witnessed a vast expansion of its internal highway system. Concurrently the number of vehicles has increased as has the average yearly milage per vehicle. Unfortunately, along with increased vehicle use there has been an alarming increase in annual loss of life and property due to traffic accidents. Statistics verify that the modem freeway systems greatly reduce dangerous head on collisions but the rate of accidents due to collisions with fixed objects in or near the roadway has increased almost 50 percent in the past thirty years.^1 In 1966, about 13>300 deaths were …

Large Deflection Analysis Of Laterally Restrained Reinforced Concrete Slabs, Satwant Singh Rihal

Civil Engineering ETDs

This dissertation is an attempt to analytically predict the large deflection behavior of orthogonally reinforced concrete slabs. The problem considered is that of a laterally restrained, simply supported square slab under uniform loading. The range of loading considered is from zero load to the load at which yielding first commences in the steel reinforcement.

This problem is first formulated using the classical large deflection theory of homogeneous plates. This formulation is based on a constant overall stiffness for the entire slab.

A modified large deflection theory is next developed for reinforced concrete slabs. In this theory concrete on the tension …

A High Voltage Regenerative Pulse Modulator, James D. Doss

Electrical and Computer Engineering ETDs

This paper describes the design of a High Voltage Pulse Modulator that employs positive feedback to generate output pulses of variable width. The modulator is intended for use as a switching device to drive the modulating anode of a five-cavity klystron. The klystron develops more than one million watts of peak power at a frequency of 805 MHz, with duty factors up to 12%. The modulating anode voltage drive requirement is approximately 80 kV with the current drain being of the order of 0.01 ampere. The total modulator current output will be approximately one ampere with most of the current …

Improved Numerical Techniques And Solution Of A Separated Interaction Of An Oblique Shock Wave And A Laminar Boundary Layer., Ben Douglas Gay

Mechanical Engineering ETDs

Initial, boundary and differencing techniques of numerical gas dynamics were improved, and a separated interaction of an oblique shock wave and a laminar boundary layer was solved numerically.

The computing time of a Lax-Wendroff differencing technique was reduced 60 percent by making algebraic changes. Inflow and wall boundary techniques were improved, and the new techniques were verified by satisfactory solutions of plain laminar boundary layers and unseparated interactions of oblique shock waves and laminar boundary layers. The differencing technique was numerically unstable for separated interactions.

Results of a sample all-centered differencing technique agreed with those of a Lax-Wendroff technique for …

Cold-Rolled Austenitic Stainless Steel: Materials Properties And Structural Performance, George Winter, S. T. Wang

CCFSS Library (1939 - present)

The cold reduction in thickness of austenitic stainless steel sheet brings about the following significant characteristics of material properties: 1) higher strength with an increasing amount of cold working, 2) more pronounced anisotropic material properties with increasing cold working, 3) stress strain relations different in tension and compression and depending on directions, and 4) nonlinear stress strain curves with relatively low elastic limits, especially in longitudinal compression. In addition, local buckling is encountered in thin walled structural members. These are the problems associated with the structural design of stainless steel members. The purpose of this investigation is to develop the …

A Noise Figure Lower Bound And A Frequency Converter, Grant Myers

Department of Electrical and Computer Engineering: Faculty Publications

This article establishes a lower bound for the noise figure of two networks in cascade. This is illustrated by means of a passive low-level frequency converter which utilizes a back diode as a nonlinear conductance. Other investigators have analyzed the properties of low-level frequency converters. However, the greatest lower bound of a combination of the converter and intermediate frequency amplifier system was not considered previously and is the subject of this paper. Knowledge of this lower bound has practical significance because if a measured value of noise figure is less than this lower bound, it follows that the measurement is …

Use Of A Tungsten Filament Lamp As A Pirani Gauge For Continuous Gas Analysis, Donald S. Remer, Fredrick H. Shair

All HMC Faculty Publications and Research

Reported herein is a thermal conductivity technique by which continuous and quantitative data have been obtained in a cataphoretic system without sample withdrawal.

Chemistry Of The Oxidant, Ferrate, Its Interaction With Specific Organics Found In Waste Water, Donald H. Williams, J. T. Riley

KWRRI Research Reports

It became obvious during this investigation that while much work has been done with ferrate (VI) chemistry, discrepancies existed in the literature and very little attention had been given possible engineering uses. This work attempted to fulfill these two needs in an exploratory manner.

The preparative techniques were reviewed and mechanical improvements made in one which allowed improved yields. Essentially what was done was to enlarge and improve the filtering technique of the product and use cooler temperatures throughout the preparation. This greatly shortened the time required. Then it was learned that the addition of ethyl alcohol to the final …

An Experimental Study Of A Type Of Vortex Sink Rate Sensors, Rao V. Arimilli

Mechanical & Aerospace Engineering Theses & Dissertations

In order to study the flow field in the sink region of a vortex Sink Rate Sensor, an experimental study was initiated .. Using two probes, one for the total pressure measurements and the other for the static pressure measurements, data was collected for two flow rates, various rates of rotation and at various points in the sink region of the flow. For the sensor (coupler inside diameter 5.0 inches and height 0.50 inches) with slenderness parameter of unity, four important conclusions were drawn from the data. At a given location in the flow field the magnitude of the tangential …

Diffusion Coefficients Of D-Glucose In Aqueous Carboxymethylcellulose And Carboxypolymethylene Solutions, A. L. Huang, S. V. Desai, Robert M. Wellek

Chemical and Biochemical Engineering Faculty Research & Creative Works

A micro interferometric method was used to determine pseudo-binary, molecular diffusion coefficients for diffusion of D-glucose in aqueous carboxymethylcellulose (CMC) and aqueous carboxypolymethylene (Carbopol) solutions. An initial solute concentration of about 9 wt. % D-glucose in the aqueous polymer solutions was used. The polymer concentrations for the CMC solutions ranged from 1.2 to 2.2 wt. % and for the Carbopol solutions from 0.18 to 0.28 wt. %. Diffusion coefficients were determined as a function of reduced solute concentration, both with and without the effect of solution volume change during diffusion being considered. © 1969, American Chemical Society. All rights reserved.

Simulation And Analysis Of A Second-Order System With An Added Finite Pole And/Or Zero, William Robert Bodwell

Electrical & Computer Engineering Theses & Dissertations

An original system whose transfer functions consist of two infinite zeros and two finite poles is modified by the addition of a finite pole and/or finite zero. Statespace techniques are used to obtain equations for simulating the transfer functions on both analog and digital computers. Sample cases were selected and simulated to demonstrate the various types of responses. Analysis of the computer results and mathematical analysis of the transfer functions provide nomographs for estimating the response of the systems to a step-input and methods for obtaining equivalent pole/zero configurations.

A Computer Program For Determining Hinshelwood Rate Mechanisims From Nonisothermal Pellet Data, Joseph J. Atkins

Theses

Methods of determining Hinshelwood rate correlations from non isothermal catalyst data was studied. It was determined for any chemical system involving a reacting gas mixture over a porous catalyst a node analysis could be used to determine chemical concentration and temperature variation through the pellet. Calculation performed with a spectra 360/Fortran 4 program defined the Hinshelwood equation from estimated surface rates. Then utilising nods analysis to determine concentration and temperature variance, transport and rate equations were integrated through the pellet to obtain a total pellet rate of reaction. For acceptance of Hinshelwood equations the calculated total rate must equal the …

P-V-T Properties Of Hydrogen And Mixtures Containing Hydrogen (With A Generalized B-W-R Equation Of State), Arnold Brief

Theses

A Generalized B-W-R Equation of State is tested for hydrogen which is a quantum gas and for systems containing hydrogen.

The gases and systems studied are: hydrogen, nitrogen-hydrogen methane-hydrogen and ethane-hydrogen.

The pressure is calculated using observed P-V-T data and the deviation is computed therefrom. For the pure gas, hydrogen, the generalized equation is compared against the original B-Vi-R equation. For mixtures, the Gunn-Chueh-Prausnitz method which is used to calculate the pseudo-critical conditions of the mixture is compared against the Prausnitz-Gunn method.

The ranges studied in this paper are as follows:pure hydrogen 30-773°K and 1 to 1200 atm., n itrogen-hydrogen …

A New Technique For The Solution Of Free Convection Mass Transfer Boundary Value Problems, James Lewis Putman

Theses

Free convection mass transfer in boundary layer flow due to density difference in an isothermal model was studied. Previous work was examined and a quasilinearization technique was chosen to linearize the system of nonlinear partial differential equations resulting from the boundary layer continuity, momentum, and diffusion equations. This system of linear ordinary differential equations was solved by a computer program utilizing an iterative Gauss Jordan matrix solution technique. Results are presented and the convergence rate of the variables is plotted for each variable as a function of the distance from the boundary layer.

Thin Layer Ionophoresis Of Sugars, Joseph Gilbert Vrindten

Theses

In 1952, Consden and Stanier published a report on paper ionophoresis of sugars in which they showed experimentally an increase in mobility of sugars with increasing pH in borate buffers. The object of the experiments in this thesis was to determine if this finding was also true of thin layer plates, there being no published literature on similar experiments using thin layer ionophoresis.

Glass plates 20 cm. x 20 cm. were coated with a 300 micron layer of cellulose powder and dried at 105° C. for one hour. They were then stored in an airtight tin box until ready for …

Enthalpy Deviations For The System Methane - Carbon Dioxide, Fred S. Winter

Theses

Enthalpy deviations for the gaseous system, Methane and Carbon Dioxide were developed using the Redlich-Kwong equation of state. Values of enthalpy deviation were obtained at 0.0, 0.0852, 0.19912, 0.3583, 0.6685 and 1.0 weight fraction Methane, at temperatures of 100° F, 280° F and 460° F, at pressures between 200 and 10,000 PSIA.

A computer program in Fortran IV language was developed for solving the Redlich-Kwong equation in terms of the compressibility factor.

The Redlich-Kwong expression for enthalpy deviation, in combination with graphical methods was used to produce the results.

Rheology Of Asbestos Filled Polystyrene, Richard Henry Young

Theses

A capillary rheometer was used to generate data showing the volumetric flow rate at various pressures for a polystyrene resin and for an asbestos filled polystyrene. Variables evaluated were per cent asbestos and temperature. These data were then used to calculate the maximum shear stress at the capillary wall and the corresponding maximum velocity gradient (shear rate) at the capillary wall. A rheological equation containing three constants was employed to relate the shear stress to the shear rate. In addition, a simple relationship was found between the values of two of the constants and the per cent asbestos. There is …

Correlation Of 1/F Noise With Threshold Drift In Mosfet's, John Peter Rooney

Theses

A brief review of the fundamentals of MOSFET's is given. A correlation between threshold drift and surface states is made, with a following correlation between surface states and 1/f noise. It therefore follows that MOSFET's with a high 1/f noise level will drift more than those with a low level of 1/f noise. Experiments were carried out to show this effect, but no clear cut conclusions can be drawn from the experimental work.

Hypothetical Liquid Fugacity Coefficients, Douglas F. Patterson

Theses

The object of this thesis was to derive values of the hypothetical liquid fugacity coefficient of carbon dioxide for various temperatures and pressures. Most of the temperatures studied were above the critical temperature of carbon dioxide and thus carbon dioxide could not truly exist as a pure liquid. Hence the prefix "hypothetical" was used to acknowledge this apparent discrepancy. Carbon dioxide was purposely chosen for this reason. Also,the necessary data for carbon dioxide were generally more available than for any other normally gaseous solute.

The hypothetical liquid fugacity coefficients were derived from the published binary vapor-liquid equilibrium data of carbon …

The Effect Of Flow Rate And L/D Ratio On The Frequency Response Of Water Fluidized Beds, Arnold Ludke

Theses

In this investigation, the dynamics of a water fluidized bed with varying L/D ratio and flow rate were analyzed both theoretically and experimentally, and the results of the two were compared.

The theoretical analysis was based on the standard method of Laplace transforms and transfer function synthesis.

The experimental investigation was conducted using standard frequency response techniques.

The mathematical model used consisted of a series of non-interacting perfectly mixed cells plus a distance velocity lag.

At low flow rates (3 to 6 times minimum fluidization velocity) the experimental data (in the form of Bode plots) were found to be in …

The Effect Of Organic And Inorganic Salt On The Relative Volatility Of Non-Aqueous Systems, Glenn W. Lindberg

Theses

The effects of dissolved salts on the vapor-liquid equilibrium of two non-aqueous binary systems have been studied. Vapor-liquid equilibrium data were taken for the binary systems ethanol - n-hexane and ethanol - hexene-1. Then potassium acetate was dissolved in each of the binary systems at a level of 1.5 mole per cent and equilibrium data were collected. The effect of the dissolved potassium acetate at this low concentration was found to be minimal.

Greater levels of salt solubility could be achieved only in the binary systems containing high ethanol concentrations. Consequently, the 15 mole per cent n-hexane in ethanol binary …

Stability Analysis Of Nuclear Reactor Feedback System, Ashok K. R. Bizzul

Electrical and Computer Engineering ETDs

A nuclear reactor feedback control system is analyzed for stability conditions in frequency domain by two methods. The nuclear reactor is modeled by a single delayed neutron group model, and the methods of analysis are Popov's analysis and describing function analysis. The feedback system with linearized nuclear reactor model is analyzed by Popov's method. A more exact non-linear reactor model is used in the feedback control system for describing function method of anal­ysis. It is found by both methods that the system is absolutely stable. But describing function analysis gives greater insight to the study of the relative stability of …

Test 1017: Allis-Chalmers 220 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

Explanation of Test Report Preparation for Performance Runs Belt or Power Take-off Performance Maximum Power and Fuel Consumption Varying Power and Fuel Consumption Drawbar Performance Varying Power and Fuel Comsumption Maximum Power with Ballast Maximum Pull without Ballast Varying Power and Travel Speed with Ballast

The 1966 Eruption Of Izalco Volcano, El Salvador, William I. Rose, Richard E. Stoiber

Department of Geological and Mining Engineering and Sciences Publications

During October–November 1966 900,000 m³ of olivine basalt flowed from the flank of Izalco volcano, El Salvador. The total heat energy was approximately 10¹⁵ calories. No measurable changes in gravity occurred at stations on the active cone between August 1964 and August 1967. In the summit crater fumaroles have surface temperatures as high as 540°C. The cooling rate of these fumaroles was 18°C/yr before the eruption and 45°C/yr after. Yearly temperature cycles due to wet and dry seasons are superimposed on the general cooling trend. The rate of gas emission at four fumaroles in November 1967 was 86 …

Test 1015: John Deere 4520 Syncro Range, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1014: John Deere 4520 Power Shift, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

A Numerical Study Of The Coanda Effect., Soloman P. Chavez

Mechanical Engineering ETDs

A numerical solution for the flow in a two-dimensional bistable fluid amplifier is obtained. A minimum Reynolds number is found below which attachment will not occur. The study shows the quality of attachment and attachment point varying with Reynolds number.

Accidents At Median Crossovers, Gordon R. Garner

Kentucky Transportation Center Research Report

Safety improvements are often controversial subjects, especially when the subject is highways. Judgments must be made weighing lives and injuries against the hard realities of financing the construction and maintenance of highway systems. Median crossovers on rural and urban freeways and expressways are controversial design features. State police and maintenance forces claim that median crossovers are necessary and essential for their work and that more frequent location of crossovers is desirable. Engineers involved with highway safety maintain that crossovers create accidents, are not necessary, and should be eliminated. When working on an accident study evaluating median type, it became obvious …