Digital Commons Network^™

Chromatographic Determination Of Hydrocarbons Based On Retention Time Data For Squalene And Tetracyanoethylated Pentaerythritol Columns, Mehdi Honarpour

Masters Theses

"The purpose of this thesis is to investigate the theory that when several members of a homologous series are injected into a gas chromatograph, at a given flow rate and column temperature, the lograrithm of their retention time as a function of some increasing property of the homologous series may be presented as a straight line and to develop their equations. Experimental procedure was accomplished for the normal paraffin series with 7 1/2% squalene and 10% Tetracyanoethylated Pentaerythritol (T.C.E.pageE.) columns and the relation between retention time and carbon number was determined. The same type of development was employed for aromatic …

The Anodic Dissolution Of Tin In Acidic Chloride Solutions, Edward Chung-Hong Liu

Masters Theses

"The anodic dissolution of Sn in acidic chloride solutions (pH = -2.0 to 2.9) was studied at 25ºC. The apparent valence of the dissolving ions varied from about 0.4 to 2.4, a function of both electrolyte and c.d. The complexing of Sn⁺² by Cl⁻ had an important influence with SnCl₃⁻ apparently being the dominant products. A reaction sequence is proposed involving the step-wide oxidation of Sn accompanied by reaction with Cl⁻"--Abstract, page 1.

Effect Of Surface Conditions On Nucleate Pool Boiling Of Refrigerant-11, Abbas M. Sinnarwalla

Masters Theses

"The purpose of this investigation was to determine the effect of surface conditions on the heat transfer for nucleate pool boiling from flat horizontal surfaces. Experiments were carried out using Refrigerant-11 at atmospheric pressure as the test fluid with Inconel-600 as the heater material. The heat transfer coefficient was determined for mirror finished, chemically etched, glass beaded and sandpaper roughened heater surfaces over heat flux ranging for 0 to 18000 BTU/HR SQ FT. At a given heat flux, the heat transfer coefficient was found to be the lowest for mirror finished surface and the highest for sandpaper roughened surface"--Abstract, page …

Thermal Expansion Of Orthorhombic Pbo, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Thermal expansion of orthorhombic PbO was investigated by high‐temperature X‐ray diffraction. The coefficients in the a0, and c0 directions are equal and Pb–O chains extended in the a0 direction and bonded into layers in the b0 direction; appreciable Pb–Pb bonding is indicated. Coordination and bond distances observed in PbSiO3 and lead silicate glasses, which are similar to those of massicot, and PbnOn polymeric units reported in PbO vapor are interpreted as additional evidence of the importance of PbO chains as structural entities. Copyright © 1970, Wiley Blackwell. All rights reserved

Radiative Heat Transfer Analysis From A Heated Airport Runway To Fog, Gordon L. Scofield, Tom J. Love

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Radiative heat transfer between a plane source and an aerosol is investigated through the Monte Carlo method. Thermal energy is transferred from a long rectangular source to monodisperse natural fog models. The analysis is only for radiative transport and does not include convection which would be coupled in a complete analysis. Direct energy transfer to the droplets of the aerosol is investigated for values of extinction coefficient of 10 km-1 and 80 km-1, absorption coefficient to extinction coefficient ratios of 0·4 and 0·5, and scattering functions of the strong forward and isotropic types. Monochromatic radiation at a wave length of …

On The Longitudinal Impact Of Two, Thin, Viscoelastic Rods, A. G. Behring, R. B. Oetting

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A one-dimensional representation of the distribution of stress and strain resulting from the longitudinal impact of two elastic rods is developed. A form of the "correspondence principle" is then used to obtain series solutions for stress and strain distributions resulting from the longitudinal impact of two rods of a "Maxwell material." Results of the viscoelastic solutions, obtained by use of nondimensional variables, are presented graphically. © 1970 by ASME.

A Systematic Study Of Instrument Variables Upon The Accuracy Of Microprobe Analysis, R. A. Parr

Masters Theses

"The purpose of this investigation was to study the effect of instrument parameter changes upon X-ray intensity measurements of the copper-manganese system. The parameters utilized in this study included: (1) polished, contaminated, and 600 grit surfaces ; (2) constant sample current and constant beam current modes; and (3) 15 KV, 20 KV, and 25 KV accelerating potentials. Inspection of the data disclosed three interesting points: (1) copper and manganese X-ray intensity measurements appear to be a linear function of composition in the 15 KV through 25 KV accelerating potential range; (2) electron backscatter measurements consistently show in a limited range …

An Investigation Of The Adjustable Element Concept For Design Of Automotive Exhaust Mufflers, Phillip Scott Gegesky

Masters Theses

"The concept of the adjustable muffler is felt to be a step in the direction of easing the present tedium of constructing and testing prototype mufflers. The evaluation of such a muffler also furthers the knowledge of the interaction of acoustic elements. A review of past and present efforts in the design and evaluation of acoustic filters and filter elements is herein presented. Some consideration is given to phenomena, such as tube attenuation and transverse modes of vibration, which are encountered in muffler evaluation techniques. The characteristics of wave guides are discussed at length. The solution of the plane wave …

Mass Transfer From Spherical Gas Bubbles And Liquid Droplets Moving Through Power-Law Fluids In The Laminar Flow Regime, Robert M. Wellek, Cheng Chun Huang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calculated mass transfer coefficients for the continuous phase are presented for internally circulating spheres of a Newtonian fluid traveling through a power-law-type continuous phase in the so-called creeping-flow region. The Nakano and Tien stream functions allow the Sherwood number to be computed as a function of the Peclet number, power-law index, and a viscosity ratio parameter. The Hirose and Moo-Young relation is shown to be a limiting case of this numerical solution. Mass transfer rates increase as the fluids become more pseudoplastic and/or the continuous phase consistency index increases, all other factors held constant. © 1970, American Chemical Society. All …

The Oxidation Kinetics Of Liquid Lead And Lead Alloys, Thomas Edward Weyand

Doctoral Dissertations

"Liquid lead and lead-silver alloys were investigated to determine the rates and products of oxidation in pure oxygen at temperatures of 350 to 600°C. The kinetic data were determined using a Cahn electro-balance. Liquid lead was found to follow a cubic rate of oxidation between 350 and 400°C. A parabolic rate was found at temperatures above 400°C. 0.496% silver and 2.258% silver alloys followed a cubic rate of oxidation from 350 to 550°C and tended to approach a parabolic rate of oxidation above this temperature. Silver additions were found to increase the rate of oxidation as compared to the pure …

A Computer Simulation Of Mine Air Shaft Thermodynamics, Ambyo Sumopandhi Mangunwidjojo

Doctoral Dissertations

"Several earlier investigations have been conducted into various aspects of heat problems in underground mines. The application of general gas laws and thermodynamics in the approach of mine ventilation has been helpful in elucidating certain difficulties associated with the subject. By combining several of the techniques perfected by these researchers and applying Carrier's method of calculation for heat flow from exposed rock strata into a workable plan, a method was developed whereby it is possible to accurately and conveniently predict the quality of working environment at any point within a deep mine. The findings of this study may be of …

Higher Space Mode Analysis Of A Large Cylindrical Pulsed H₂O System, Harold David Hollis

Doctoral Dissertations

"By utilizing a geometrically centered pulsed source internal to a large (B²_g) ≈ 0.002) cylindrical H₂O system, the neutron flux was measured as a function of position and time. A least square fit of the data yielded the fundamental and five higher decay constants and amplitudes of the thermal neutron flux. Symmetrical and enhanced neutron densities were obtained as a result of the internal source. Long waiting times were unnecessary and data acquisition was accelerated.

The decay constants were found to be independent of position, pulse width, counting time and rates, method of normalization, or waiting time. …

Binary Molecular Diffusivities In Liquids: Prediction And Comparison With Experimental Data, Ronald Dean Mitchell

Doctoral Dissertations

"The Eyring rate theory equation has been modified successfully to enable predictions of binary molecular diffusivities for a wide variety of liquid-liquid systems. The activation free energy for binary diffusion has been evaluated in terms of the activation free energies for self diffusion of the solvent and solute. This was accomplished through the use of regular solution theory by relating the bond breaking energy of the jump step to the bond breaking energy in evaporation. Diffusivities estimated by this equation and the equations developed by Olander, by Gainer and Metzner, and by Wilke and Chang were compared with experimental data. …

Development And Application Of Cartesian Tensor Mathematics For Kinematic Analysis Of Spatial Mechanisms, Robert Myrl Crane

Doctoral Dissertations

"The complexity of spatial mechanisms in themselves and the absence of an attractive analytical tool for their study has left this field of engineering analysis largely unexplored. In recent years several analytic methods have emerged. One of the most attractive of these is the tensor method. Literature surveys reveal that the tensor method is largely unexploited in the U.S.A., with regard to spatial mechanisms as well as simpler kinematic problems. The purpose of this work is to develop tensor mathematics for application to the kinematic analysis of spatial mechanisms. Methods are developed for position solutions and the determination of velocities …

Temperature Variation In Distribution Of Relaxation Times In Aluminosilicate Glasses, David Wayne Moore

Doctoral Dissertations

"The distribution of relaxation times for the alkali peak in a Li₂ O·A1₂O₃ ·2.0SiO₂ glass and for the mixed alkali peak in a 0.5Li₂O·0.5Na₂O·A1₂O₃·2.OSiO₂ glass was studied using the internal friction technique. A lognormal distribution of relaxation times provided the best agreement with the experimental data. The ß parameter of the lognormal distribution function, which is related to the half-height peak width, varied with temperature, indicating that the distribution of relaxation times is dependent upon the activation energy and the activation entropy of the relaxation mechanism. The major contributor to the distribution of relaxation times is a wide distribution in …

The Deformation Mechanisms In Sublimed Magnesium Under Cyclic Loading, Babu Narian Thakur

Doctoral Dissertations

"A detailed study of the deformation processes in sublimed magnesium under reverse bending fatigue in air at room temperature has been undertaken utilizing the light, scanning and transmission electron microscopy. The Principal deformation modes are the basal slip and {10Ī2} twinning. The proportion of twinning increases markedly with the increasing stress level and the number of cycles. The evidence for cross slip is seen on the basal slip bands. The extrusions are seen not only along the basal slip lines but also along the {10Ī2} twin boundaries. In the later stages of fatigue, the extrusions chip off producing a notch …

A Model For Predicting The Energizing Transients Of Station Capacitor Banks, Dennis Oliver Wiitanen

Doctoral Dissertations

"A model for predicting the transients associated with energizing ungrounded wye-connected station capacitor banks was developed. The model has the capability of simulating non-simultaneous operation of the breaker poles, pre-insertion resistors, and the presence of previously energized capacitor banks at the same station. To investigate various system representations, a computer solution of the transient response of an arbitrary network and the computer solution of the generalized Thevenin impedance of a complex network are presented. A simple power system is defined and used to investigate the modeling of various system components, using the computer solution methods. Simplification of the model due …

A Simulation And Diagnosis System Incorporating Various Time Delay Models And Functional Elements, David Michael Rouse

Doctoral Dissertations

"The application of digital simulation to all phases of digital network design is considered here as oppossed [sic] to development of simulation for one or two restricted parts of the digital process. For this reason a simulator is presented which can be consistent by varying the level of expression from the simulation of architectural structures to such detailed simulation requirements as race analysis of asynchronous sequential circuits. In order to make system simulation more than just an idea, it must be capable of handling large circuits in reasonable times. It is demonstrated that functional simulation has the potential to increase …

A Three-Dimensional Mathematical Simulator Of Multiphase Systems In A Petroleum Reservoir, Leonard Koederitz

Doctoral Dissertations

"A generalized digital analysis for calculating three phase, three dimensional flow in reservoirs is developed. The computerized mathematical model is applicable to depletion drive, gas injection, water injection, and/or aquifer drive systems with modifications specific to the simulation criterion of that type of drive and includes fluid compressibility effects, gravity drainage and capillary pressure. The simulation allows arbitrary consideration of reservoir heterogeneity, geometry, well locations and rates of production. An innovation to the alternating direction technique for linear differential equations discussed by Brian is developed and employed in order to render the method of solution applicable to non-linear differential equations. …

Effects Of Cold Work In Cold-Formed Steel Structural Members, S. J. Britvec, Alexander Chajes, K. W. Warren, Jairo Uribe, George Winter

CCFSS Library (1939 - present)

No abstract provided.

Influence Of Ductility On The Structural Behavior Of Light-Gage Cold-Formed Steel Members, A. K. Dhalla, George Winter, S. J. Errera

CCFSS Library (1939 - present)

Ductility parameters defined in the second progress report were previously obtained by conducting tension coupon tests on specially produced A and S steels. In this report, tension coupon test results are presented for a 20 gage commercial low ductility steel, i.e. an ASTM Grade E steel, herein designated as steel B. Its behavior is compared with that of the specially rolled A and S steels to test the validity of conclusions arrived at in the second progress report. Test programs were set up to study the behavior of B steel under static tension loading, one program for single bolted connections …

Discrimination Of Signal And Noise Events On Seismic Recordings By Linear Threshold Estimation Theory, David Nuse Peacock

Doctoral Dissertations

"The object of this study is the investigation of a linear threshold element technique for identifying surface multiples on a single seismic trace. Traces of seismic events were generated which contained primaries, surface multiples, and various levels of Gaussian random noise. Since it was necessary to separate the events as much as possible, the traces were subjected to pulse-compression deconvolution processing prior to LTE analysis. Mean frequency, peak frequency, amplitude spectrum variance, periodicity, and polarity were employed as pattern parameters. A set of weights was found that would maximize the moment of inertia of the S line distribution of the …

An Investigation Of Nucleate And Film Boiling Heat Transfer From Copper Spheres, William David Hardin

Doctoral Dissertations

"This study consisted primarily of a laboratory investigation involving nucleate and film boiling heat transfer from copper spheres with saturated liquid nitrogen at atmospheric pressure. An initial study was directed towards obtaining reproducible boiling heat flux versus ΔT curves in the nucleate boiling region from surface conditions created by single and/or multiple glass bead peenings. The variables of bead size, nozzle line operating pressure, and distance a copper surface should be placed from the nozzle outlet were checked. The results indicated that a final peening of the surface with 0.0017-0.0035 inch diameter glass beads, a nozzle line pressure of approximately …

Mass Transfer From Spherical Gas Bubbles And Liquid Droplets Moving Through Power-Law Fluids In The Laminar Flow Regime, Cheng-Chun Huang

Doctoral Dissertations

"Continuous phase mass transfer coefficients are presented for internally circulating spheres of a Newtonian fluid traveling through a power-law type continuous phase in to so-called creeping-flow region. The Nakano and Tien stream functions allow the Sherwood number to be determined as a function of the Peclet number, power-law index, and a viscosity ratio parameter. The Hirose and Moo-Young relation is shown to be a limiting case of this solution. Mass transfer rates increase as the fluids become more pseudoplastic and/or the continuous phase consistency index increases, all other factors held constant"--Abstract, page ii.

Some Effects Of Oh Groups On Sodium Silicate Glasses, Mokhtar Sayed Maklad

Doctoral Dissertations

"Glasses of various compositions in the Na₂O-SiO₂ system were prepared with different levels of OH concentration. Phase separation kinetics, thermal expansion, radiation induced optical absorption, and internal friction of these glasses were studied. The increase in OH content in these glasses was found to (a) enhance the rate of phase separation; (b) increase thermal expansion above the glass temperature and change the dilatometric softening temperature in a way that depends on microstructure; (c) increase the radiation induced optical absorption bands associated with positive hole centers and decrease those associated with electron trap centers; and, (d) decrease the low temperature alkali …

The Cathodic Reduction Of Maleic Acid, Show Yih Hsieh

Doctoral Dissertations

"The electrochemical reduction of maleic acid (0.0003 to 0.3 M) was studied on Hg, 0.5% Bi(Hg) amalgam, 5.0% Bi(Hg) amalgam, and Bi cathodes in 1 n H₂SO₄-K₂SO₄-KOH electrolytes (pH 0.3 to 4.0) at 60°C. The maleic acid was converted to succinic acid with high efficiencies (86 to 100%) on all cathodes. Polarization curves with linear Tafel sections were found. All the cathodes had similar kinetic parameters...A reaction mechanism consistent with the experimental observations is proposed..."--Abstract, pages ii-iii.

Electric Field Strength Dependence Of Surface Damage In Oxide Passivated Silicon Planar Transistors, C. A. Goben

Electrical and Computer Engineering Faculty Research & Creative Works

A dependence of surface degradation induced by ionizing radiation in matched oxide-passivated silicon planar epitaxial transistors on junction fringing electric field strength present during exposure is reported. The electric field strength and gamma dose dependence are investigated of the decrease in the forward current gain, hFE (as reflected by the increase in the surface recombination current component), the increase in the surface recombination velocity (as reflected by the increase in the reciprocal of the minority carrier lifetime), and the increase in junction capacitance. Empirical prediction equations have been derived, for matched devices, correlating the normalized base current increase and the …

Etch Patterns On Zone-Refined Fe, M. E. Straumonis, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Upon dissolution of zone-refined Fe in strong acids, mainly three kinds of corrosion patterns were observed in the crystallites of the sections. Regardless of the acids, the {110} plane always appeared on the three patterns in the form of smooth and even steps, ledges, or facets. The {112}, {122}, and {123} planes were also developed but to a much lesser degree. The {100} and {111} planes were not observed because grains of the respective orientation were missing on the sections. Attempts were made to explain the formation of the planes by taking into consideration the reticular density of the planes …

Excitation Requirement For Rectified Output Ac Generators, Richard Thomas Smith

Electrical and Computer Engineering Faculty Research & Creative Works

This paper develops a method for calculating the required dc field current of a three-phase synchronous ac generator for known dc load conditions and machine characteristics. The method is simple to apply and has shown good agreement with test data. The method is of utility for preliminary design and analysis of rectified output alternators, such as may be used in excitation systems of the largest ac generators, space vehicle power applications, or high-power industrial rectification. Copyright © 1971 by The Institute of Electrical and Electronics Engineers, Inc.

State Assignment Selection In Asynchronous Sequential Circuits, Gary K. Maki, James H. Tracey

Electrical and Computer Engineering Faculty Research & Creative Works

Methods already exist for the construction of critical race-free assignments for asynchronous sequential circuits. Some of these methods permit the construction of many assignments for the same flow table. The algorithm presented here consists of two easy to apply tests which select that critical race-free assignment most likely to produce a set of simple next-state equations. The algorithm has been programmed. Copyright © 1970 by The Institute of Electrical and Electronics Engineers, Inc.