Digital Commons Network^™

Numerical Modeling Of The Early Stage Of Cloud Formation In A Simulation Chamber, Adel Nassif Saad

Doctoral Dissertations

"A numerical model has been developed to simulate the growth of cloud droplets by condensation upon a spectrum of hygroscopic nuclei. The model is applicable to cloud simulation chamber conditions as well as to the study of the role of these nuclei on cloud base microstructure.

Equations are given for the growth by condensation of water vapor on a population of hygroscopic nuclei in a volume being cooled by expansion. The equations are integrated simultaneously, using Hamming's modified predictor-corrector method for given initial conditions, to obtain the droplet size distribution, temperature, pressure, supersaturation, and liquid water content. Temperature fluctuations, sedimentation …

Solvability Of Differential Systems Near Singular Points, Leon M. Hall

Doctoral Dissertations

"Functional analysis techniques are used to prove a theorem, analogous to the Harris-Sibuya-Weinberg theorem for ordinary differential equations, which yields as corollaries a number of existence theorems for holomorphic solutions of linear functional differential systems of the form z^Dy'(z) = A(z)y(z) + B(z)y(αz) + C(z)y'(αz) in the neighborhood of the singularity at z = 0"--Abstract, page 2.

Film Formation On Anodically Polarized Lead, H. Vaidyanathan, Ram A. Narasagoudar, Thomas J. O'Keefe, William Joseph James, James W. Johnson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

A Multiple-Plan Evaluation Model For Small Ungauged Watersheds, James R. Dexter

Masters Theses

A computer solution model is proposed for simulation of the effect of alternative measures for flood damage reduction. The goal of the model is to optimize the value of an objective function which will maximize the amount of net benefits returned by the project. The evaluation includes unit hydrograph synthesis, direct runoff construction, computation of average annual damages, and optimization of an objective function. A test application of the model is made on a small community affected by floods from a small ungauged stream"--Abstract, page iii.

A Comparative Analysis Of The Capabilities Of Three Stereo Radar Techniques When Operating In The Presence Of System Errors, George L. Bair

Masters Theses

"Three stereo radar techniques for producing stereo images from which topographic data and maps may be obtained are described and their performance in the presence of system errors is determined. The techniques are: an improved single flight technique which uses a combination of two antenna beam characteristics which permits terrain illumination from nearly the same aircraft position, a previously proposed single flight technique which uses two horizontal linear arrays generating vertical fan beams at different azimuth angles, and an existing two flight technique which uses a horizontal array generating a side-looking fan beam.

Error analyses are performed to determine the …

A Numerical Study Of Ordinary Differential Equations With Periodic Coefficients, Richard Bruce Schuessler

Masters Theses

"In this thesis a method for solving ordinary differential equations with periodic coefficients is derived. In addition, by utilization of Floquet theory, a theorem is given by which it is possible to determine the stability of the zero solution. Error bounds are given for the method and for the two dimensional case bounds are given for the error in the eigenvalues. Several numerical examples are given to illustrate the method"--Abstract, page ii.

A Discrete Approach To Surface Interpolation, Jerry Lee Albert Sandvos

Masters Theses

"An equidistant spacing of two dimensional data points is a requirement of most automated analysis routines. In this thesis, a method of generating such equispaced data from randomly spaced data is developed and implemented by a set of computer routines. The method represents the study area as a two dimensional spatial array, in which each array cell represents the data value of a subarea of the study area. A routine sorts and places the data in the array. Missing values in the array are interpolated from nearest neighbors. Filtering is used to smooth errors and a contouring routine is used …

A Computational Method For Determining The Growth Rates Of Saline Water Drops., Robert Alexander Fletcher

Masters Theses

"A phenomenologica1 theory is presented which describes the growth or evaporation of cloud droplets containing dissolved NaCl. The main interest is in the early stages of growth. The Maxwell-Fuchs equation is employed with refinements to account for the high sa1t concentration in small droplets. A computer program is presented that ca1culates the growth time as a function of radius for cloud droplets nucleated with NaCl.

The growth times obtainable from the Maxwe11-Fuchs equation differ significantly from the growth times ca1culated using the refined Maxwell-Fuche equation for ambient relative humidities less than or equal to 100%. Growth times for droplets nucleated …

Transient Thermal Stresses In A Sphere By Local Heating, J. B. Cheung, T. S. Chen, K. Thirumalai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of transient thermal stresses in a solid, elastic, homogeneous, and isotropic sphere is solved for uniform and nonuniform, local surface heating. The temperature solutions are obtained by using separation of variables and integral transformation. The corresponding thermal stresses are derived by superposing a particular displacement potential function on Boussinesq solutions. Numerical solutions for two particular cases of localized heating of a typical brittle spherical solid have been obtained and presented. The results indicate a tensile stress concentration in the interior of the solid below the heated zone. © 1974 by ASME.

Vibration Characteristics Of Free Thin Cylindrical Shells, Floyd M. Cunningham, D. E. Leanhardt

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper considers the flexural vibrations of free thin circular cylinders. A frequency equation is derived using free-free characteristic beam functions to represent the variation of mid-surface shell displacement components, u, v and w, with respect to the axial direction. Timoshenko strain-displacement relations for thin cylinders are used to determine elastic vibratory strain energy. Energy methods are applied to obtain the frequency equation and associated amplitude ratios for each of its roots. This energy solution is checked experimentally using a vibration exciter and numerically using the SABOR IV finite element program. With minor modification, the frequency equation conforms to the …

The Effect Of Surface Impurities On The Thermal Accommodation Of Rare Gases On A Tungsten Surface, D. Vincent Roach, Louis Biolsi, Robert E. Harris

Chemistry Faculty Research & Creative Works

A Rather Comprehensive Experimental Examination of the Effect of Surface Impurities (Potassium and Cesium) on the Thermal Accommodation of Rare Gases on a Tungsten Surface Has Been Made by Roach and Thomas. the Present Work Examines These Effects from a Theoretical Viewpoint with Particular Emphasis on the Effect on the Thermal Accommodation of Helium on a Tungsten Surface Caused by the Adsorption of Cesium Ions And/or Atoms. for This Examination, the Theory of Allen and Feuer Has Been Utilized using Reasonable Values of the Interaction Parameters for Helium with the Adsorbate as Well as the Force Constant for the Adsorbate-Substrate …

Effects Of Surfactants On Atomic Absorption Analysis Of Dilute Aqueous Copper And Nickel Solutions, Raymond L. Venable, Robert V. Ballad

Chemistry Faculty Research & Creative Works

No abstract provided.

Measurements Of The Average Electric Dipole Polarizabilities Of The Alkali Dimers, Robert W. Molof, Thomas M. Miller, Henry L. Schwartz, Benjamin Bederson, John T. Park

Physics Faculty Research & Creative Works

The average electric dipole polarizabilities of the homonuclear alkali dimers have been measured in an electric deflection experiment. The molecular results are normalized to the corresponding atomic polarizabilities by comparing deflections of atomic and molecular alkali beams passing through an inhomogenous electrostatic field. The average polarizabilities in units of 10-24 cm3 are: Li2(990°K), 34±3; Na2(736°K), 30±3; K2(569°K), 61±5; Rb2(534°K), 68±7; Cs2(515°K), 91±7. Copyright © 1974 American Institute of Physics.

Removal Of Nutrients By Sorption On Activated Alumina, Checkman Michael Yue

Doctoral Dissertations

"The nutrient enrichment of surface, primarily impounded, water and the associated problems of accelerated eutrophication and prolific algal growth have become a nationwide concern. Phosphorus and nitrogen are considered to be the key elements in abating eutrophication and are contributed from many sources, natural and manmade; prominent among these is the discharge of domestic and industrial wastes.

The purpose of this study was to evaluate the removal of nutrients, primarily phosphorus and nitrogen, with activated alumina using a continuous-flow pilot plant system. Specific objectives were the: development and construction of appropriate bench and field-scale pilot plant units utilizing the rapid …

Hydrodynamic Mixing Model Applied To A Continuous Stirred-Tank Reactor With And Without Second-Order Reaction, Leon L. Otte

Doctoral Dissertations

Paper 1: "A hydrodynamic mixing (HDM) model, used to calculate the steady-state spatial distribution of conversion for a second-order reaction in a continuous stirred-tank reactor (CSTR) for non-premixed reactants was developed and contrasted with other methods. The HDM model is based on a segmental description of the reactor and includes turbulent mixing effects in each segment. As a test of the model, the experimental results obtained from a tubular reactor were found to be very well represented for a range of reactant ratios. Spatial distributions of concentration and segregation intensity (degree of mixing) within the CSTR were determined for a …

A Kinetic Study Of The Cerium (Iv)-Oxalic Acid System In Acidic Sulfate Media., Robert Richard Kessler

Masters Theses

"The kinetics of the cerium (IV) oxidation of oxalic acid was studied by a stopped-flow spectrophotometric technique in acidic sulfate media. The media consisted of perchloric acid, sodium sulfate and sodium perchlorate which allowed for the determination and control of the various sulfate and hydroxo species of cerium (IV) at prescribed hydrogen ion concentrations. The rate of reaction decreases rapidly with increasing sulfate concentration which yields evidence against previous reports indicating Ce (SO₄)₂ and Ce (SO₄)^2-₃ as the reactive cerium (IV) species. The results indicate that Ce (SO₄)²⁺ is the …

A Computerized Simulation Of A Personal Rapid Transit System., James Richard Cromer

Masters Theses

"The movement of people from an origin to a destination has become a complex and sometimes severe problem, The present modes of transportation available, which include the rapid rail systems, bus transit service, and the personal automobile, have proven quite ineffective in dealing with the situation, A new concept in the transportation area is that of Personal Rapid Transit (PRT). This concept offers a promising solution to many of our people and goods movement difficulties. Before this new system can be implemented it is necessary that various design, construction, and operational criteria be evaluated to determine the optimal system to …

Solid Transformations And Premelting Phenomena In Fluorite Structures And The System Srcl₂Bacl₂, Damri Sukhotanang

Doctoral Dissertations

"Thermal expansion and phase transformations in CaF₂, BaF₂, SrCl₂, and BaCl₂ were studied by high temperature x-ray diffractometry, differential thermal analysis, and thermodilatometric analysis. Thermal expansion characteristics of CaF₂, BaF₂ and SrCl₂ are very similar. The structures expand normally at lower temperatures and depart substantially from linearity at higher temperatures, because of formation of defects and disordering of anions. At high temperatures CaF₂ and BaF₂ react with water vapor, even at low humidities, forming oxides and emitting HF, leading to difficulty in observation of phase transformations. SrCl …

Mechanism Of Solvolysis Of 3-Methyl-2-Butyl Brosylates., Luu Le Nghi

Masters Theses

"The brosylates of 3-methyl-2-butanol and it's a-d₁-, ß-d₁-, B-d₃-, and S-d₄- analogs have been synthesized. The solvolytic rate data for these compounds were determined. The solvolytic products in 70% (vol.) ethanol-water have been identified by flame ionization gas chromatography using a Carbowax 20M column. The amount of each product was measured by integrating the peak areas from the chromatograms. By analyzing the isotope effect data, the rate determining step is shown to be the formation of the hydrogen bridged ion pair intermediate. By evaluating the GC-mass spectral analysis of the isopentenes, a …

The Investigation Of Video Sensitivity And Data Processing Errors Encountered In An Airborne Receiver, James Lee Hamilton

Masters Theses

"The investigation of video sensitivity and both biphase demodulation and Doppler shift processing errors is performed. The effect of pass band ripple on the noise bandwidth of two pole filters is developed. The effect of feedback on the effective noise figure of a high gain IF (Intermediate Frequency) amplifier is investigated and discussed. An analysis of a limiting amplifier-biphase demodulator circuit is attempted. A computer simulation of this same circuit is also performed and the results are compared to measurements taken in the laboratory. With respect to multipath corrupted input signals, a differential phase shift keyed biphase demodulator is shown …

A Study Of Pollution Abatement From The F-15 Jet Engine Test Stand, Gary Joseph Fennewald

Masters Theses

"The pollutants emitted from jet engine test stands are carbon particles, unburned hydrocarbons, carbon monoxide, and the oxides of nitrogen. This work is a study of various ways of removing these pollutants from the test stand exhaust. The methods investigated include absorption, adsorption, electrostatic precipitation, filtration, catalytic reduction and oxidation, and thermal oxidation.

For abatement of nitrogen oxides, none of the present methods is considered to provide adequate technical reliability to proceed with an installation at this time. Each of the methods for removal of nitrogen oxides has high capital and operating cost; and, in many cases, secondary pollution problems …

Application Of An Inverse Heat Conduction Technique To A Simulated Injection Mold., Noel Joy Rytter

Masters Theses

"An analytical model was constructed to investigate the heat transfer in an injection mold for which the temperature was controlled by a special mold heating-cooling process. Several techniques were used to test the validity and accuracy of the analytical model of the mold and to explain some singularities that occurred. It was determined that the thickness of the plastic part being molded is the primary factor affecting the minimum cycle time for the molding operation. Also, abrupt changes in temperature on the molding surfaces are very difficult to obtain because this requires drastic temperature changes for the working fluid that …

A Study Of Digital Computer Control Of A Continuous Pulp Digester., Charles Edward Barker

Masters Theses

"Detailed analysis of six basic control loops for a Kamyr continuous digester is described using z- and s- transform methods. An example of a digital computer control system for a continuous digester is also presented"-- Abstract, p. ii

Graph Model Analysis Of Computer Structures, Ömür Taşar

Masters Theses

"Graph theory is applicable to the solving of problems in nearly every field of scientific study. The purpose of this thesis is to consider its applications in representing and analyzing digital computers. Fundamental graph theory definitions, the types and the properties of the directed graphs, the matrix representation, and several reduction techniques are discussed. The blocking gate method for diagnosing computer systems is described and applied to the Scientific Control Corporation (SCC) 650 for its fault-diagnosis.

Microprogramming has been a significant trend in hardware and software designs of computers. Microprogrammed computers are discussed in comparison to conventional computers. A general …

Structural Strain In Small Prenucleation Water Clusters, Donald E. Hagen

Physics Faculty Research & Creative Works

A method is developed for incorporating strain energy into a microphysical treatment of small prenucleation water clusters. The molecules are arranged in a clathrate-cage structure, and this structure is allowed to relax to minimize the strain energy resulting from hydrogen bond stretching and bending. The method is applied to various cluster sizes up to 130 molecules and the results are compared with the classical liquid drop model. The effect of anharmonic terms in the interaction is included.

Radiation Testing Under Simulated Loca Conditions, Kenneth G. Mayhan, D. R. Edwards, W. F. Oberbeck, J. F. Montle

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The purpose of this evaluation is to gather data to determine whether or not radiation during a simulated Loss of Coolant Accident would have any effect upon the coatings being used. Because of the concern in industry regarding the safety of nuclear power generating stations and the strong actions of the various environmentalist clubs and agencies clubs and agencies, the utilities have been required to prove the safety of the power facilities to extraordinary degrees before licensing can be obtained to operate. One of the areas regarding the safety is the necessity of proving that the coatings will remain intact …

Oxidation Reactions Of Unsaturated Hydrocarbons For Fuel Cells, James W. Johnson, William Joseph James, A. K. Agrawal

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The anodic oxidation of unsaturated hydrocarbons has been the subject of numerous studies, primarily on Pt and Au electrodes at low temperatures, < 100°C. The complete oxidation to CO₂ is usually the predominant reaction with both H₂O and OH^- having been proposed as the oxygen source. Usually a single study consists of a comprehensive investigation of a single compound on a single electrode or a somewhat limited study of several compounds on a single electrode. A diversity of proposed mechanisms has resulted and is illustrated by the following summary.

History Of So2 Removal System At The Meramec Plant Of Union Electric, Gerald E. Dreifke, John F. Mclaughlin, Jerrel D. Smith

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

In line with the then emerging air pollution control regulations Union Electric installed a limestone injection wet scrubber sulfur dioxide removal system on an intermediate size coal-fired utility boiler at its Meramec Power Plant on an experimental basis in September, 1968. During approximately 3 years of operation many difficulties were encountered with plugging and scaling of various system components by calcium sulphate. As a result of this experience along with related experiences by other utilities employing similar systems, the experiment was terminated in June, 1971.

As a result of the experiences gained, however, second generation experiments in sulfur dioxide removal …

Future United States Energy Demand Patterns, Leland Blank, Richard Riley

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The future energy demands of the United States are forecast using a unique approach. The saturation forecasting method reflects the inability of an individual to utilize more than a limited amount of energy. This technique also allows evaluation of various conservation methods and their effects on the future energy needs.

Evaluation Of Model For The Contributin Of Phonon-Induced Tunneling To Donor Esr Spectral Narrowing In Germanium, David L. Meier, William F. Parks, Edward Boyd Hale

Physics Faculty Research & Creative Works

The model commonly assumed to explain the narrowing of the ESR spectra of donor impurities in germanium is examined in detail. This model combines the Anderson line-narrowing theory with the Miller and Abrahams theory for the phonon-induced tunneling (hopping) of an electron between impurities. The predictions of this model are found to be in drastic disagreement with experimental results now available. It is shown that the narrowed linewidth should depend strongly on donor concentration, acceptor concentration, and temperature. Future spin-resonance experiments in highly compensated samples may show the effects of hopping, but no evidence now exists which indicates that hopping …