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32nd Rocky Mountain Conference

Rocky Mountain Conference on Magnetic Resonance

Program and registration information for the 32nd annual meeting of the Rocky Mountain Conference, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, July 29 - August 3, 1990.

Use Of A Generalized Set Of Variables In Fluid Flow Calculations, Pawel Chwalowski

Mechanical & Aerospace Engineering Theses & Dissertations

In fluid flow calculations, a set of generalized field variables is used to replace the more conventional choice of either the conserved variables, or the primitive variables. This generalized set of variables represents an infinite number of possible choices for the specific set of field variables. For algorithms of both the implicit and explicit type, the resulting effect of a change in field variables on a steady-state flow solution is in general relatively small. However, for implicit algorithms, a consistent linearization with respect to the new variables results in dramatic changes in the overall matrix conditioning of the linear systems …

An Artificial Neural Approach To The Decomposition Problem, Chandrashekar L. Masti

Electrical & Computer Engineering Theses & Dissertations

The goal of this thesis is to develop an artificial neural approach toward addressing the intractability involved with the decomposition problem. The search for the lattice of substitution property (s. p.) partitions essential to decompositions is cast into the framework of constraint satisfaction. An artificial neural network is developed to provide solutions by performing optimization of a mathematically derived objective function over the problem space. The issue of transitivity is verified to belong to a class of problems beyond the scope of solvability for conventional quadratic-order constraint satisfaction neural networks. A theorem is stated and proved establishing that third-order correlations …

Kerr Effect Of Two-Medium Layered Systems, Liang-Yao Chen, William A. Mcgahan, Z.S. Shan, David J. Sellmyer, John A. Woollam

David Sellmyer Publications

Detailed and practical expressions are given for the magneto-optical Kerr effect (MOKE) for various configurations of two media. One is a magneto-optic (MO) one, and the other is a nonmagnetic (NM) medium. For a system of two thick media with a single interface, with a first-order approximation in MOKE term Q, the Kerr function is determined by the product of a MOKE term Q and an optical term η. A second type of system includes a thin MO (or NM) layer deposited on a thick NM (or MO) substrate. For a MO/(NM-substrate) configuration, the Kerr function is related to …

Mars And Beyond: The Solar System Beckons, Frank J. Redd

Faculty Honor Lectures

To space zealots, 1989 was the year the drought ended. The space shuttle was operational again; Voyager's grand reconnaissance of the Solar System climaxed with the glorious encounter with the planet Neptune and its startling moon, Triton; the launches of the Magellan spacecraft to Venus and the Gallileo to Jupiter broke a decade long hiatus in the launch of U.S. planetary missions; and, for the first time in over twenty years, a U.S. president announced a daring new initiative in human exploration with the goal of first returning humans to the Moon, then going on to Mars.

On-Line Process Fiber Optic Refractometer For Measuring Edible Oil Hydrogenation, Charles F. Cole, Robert A. Sims, Alois (Al) J. Adams

Journal of the Arkansas Academy of Science

The process of edible oil partial hydrogenation has improved steadily over the past decades, but few on-line process instruments exist capable of measuring the extent of hydrogenation. This work describes the design of a prototype, on-line fiber optic refractometer for controlling and monitoring of oils. It uses an established correlation between the degree of hydrogenation of an edible oil and its refractive index (Rl). The refractometer cell uses a bare optical fiber in direct contact with processing oil. Equations are given describing the power transmission characteristics of an optical fiber as a function of its cladding Rl. Comparisons between calculated …

Winds In The Upper Mesosphere At Mid-Latitude: First Results Using An Imaging Fabry-Perot Interferometer, D Rees, A Aruliah, T J. Fuller-Rowell, Vincent B. Wickwar, R J. Sica

All Physics Faculty Publications

The first stage of a new midlatitude facility at the Hardware Ranch Observatory near Bear Lake (41.93°N, 111.42°W, 1970 M elevation), for studies of the aeronomy of the middle and upper atmosphere, was completed during early September 1989. An Imaging Fabry‐Perot interferometer (IFPI) (Rees et al., 1982; Rees et al., 1990), was commissioned with a special Imaging Photon Detector (IPD) (McWhirter et al., 1982), equipped with a Gallium Arsenide (GaAs) photocathode. Wind and temperature structure can be deduced from observations of the Doppler shift and Doppler broadening of airglow and auroral emissions from the mesosphere and thermosphere. The near infra‐red …

Transition Probabilities And Franck-Condon Factors For The Second Negative Band System Of O2+, Jane L. Fox, Alexander Dalgarno

Physics Faculty Publications

Transition probabilities for the second negative band system of O₂⁺ are computed using the dipole transition moment presented by Wetmore et al. [1984]. Vibrational levels υ″ = 0 − 54 of the X²Π_g ground state and υ′ = 0 − 33 of the excited A²Π_u state are included. Franck-Condon factors for ionization-excitation of O₂ (X³Σ_g⁻; υ = 0 − 25) to O₂⁺(A²Π_u;υ′ = 0 − 33) are also presented.

A Signature Of Auroral Precipitation In The Nightside Ionosphere Of Venus, Jane L. Fox, H. A. Taylor Jr.

Physics Faculty Publications

We show here that the densities of mass-28 ions measured by the Pioneer Venus Orbiter ion mass spectrometer (OIMS) on the nightside of Venus are highly variable and show little correlation with the values of the O⁺ densities. We have determined the total production rates of mass-28 ions in the chemical equilibrium region and find that this production rate cannot be explained by known chemical production reactions. We propose that the “excess” production is due to precipitation of electrons into the nightside thermosphere.

Optimization And Thermodynamic Performance Measures Of A Class Of Finite Time Thermodynamic Cycles, Joseph D. Walters

Dissertations and Theses

Modifications to the quasistatic Carnot cycle are developed in order to formulate improved theoretical bounds on the thermal efficiency of certain refrigeration cycles that produce finite cooling power. The modified refrigeration cycle is based on the idealized endoreversible finite time cycle. Two of the four cycle branches are reversible adiabats, and the other two are the high and low temperature branches along which finite heat fluxes couple the refrigeration cycle with external heat reservoirs.

This finite time model has been used to obtain the following results: First, the performance of a finite time Carnot refrigeration cycle (FTCRC) is examined. In …

Self-Consistent Effective Binary Diffusion In Multicomponent Gas Mixtures, John D. Ramshaw

Physics Faculty Publications and Presentations

The correct treatment of diffusion in multicomponent gas mixtures requires solution of a linear system of equations for the diffusive mass fluxes relative to the mass-averaged velocity of the mixture. Effective binary diffusion approximations are often used to avoid solving this system. These approximations are generally internally inconsistent in the sense that the approximate diffusion fluxes do not properly sum to zero. The origin of this inconsistency is identified, and a general procedure for removing it is presented. This procedure applies equally to concentration, forced, pressure, and thermal diffusion, either separately or in combination. It is used to obtain a …

University Based Multidisciplinary Organizations - Promises And Challenges, Robert L. Cook, Richard D. Benton, Robert A. Green

Journal of the Arkansas Academy of Science

The Diagnostic Instrumentation and Analysis Laboratory (DIAL) at Mississippi State University is a multidisciplinary research organization engaged in developing and applying advanced computer-controlled, optical and laser-based diagnostic instrumentation systems for the characterization of high temperature gas streams. Part of the mission of DIAL is the on-site application of the diagnostic systems to large-scale facilities. The laboratory has approximately 40 professional and support personnel. Twelve faculty members are associated with the laboratory and, because of the multidisciplinary nature of the research program, their disciplines cross college as well as departmental boundaries. This provides for unique graduate research opportunities. Moreover, the laboratory …

Principles And Clinical Applications Of Magnetic Resonance, Rao P. Gullapalli, Teresa T. Evans, Roger M. Hawk

Journal of the Arkansas Academy of Science

A review is presented which covers the basic theory of nuclear magnetic resonance (NMR) with regard to angular momentum, magnetic moments, and the classical mechanical description of the NMR experiment. Longitudinal (T,) and Transverse (T2) relaxation times are defined as well as the basic pulse sequences used for their measurement. In particular, the 180°-t-90° and the Hahn Spin Echo pulse sequences are described in detail. Basic Magnetic Resonance Imaging (MRI) theory is discussed with regard to slice selection, frequency encoding, and phase encoding to define the imaged volume element. The equations defining the amount of Tt , T2 , and …

Status Of The Accelerator Project At Uca, Jack Gaiser, Harold L. Pray

Journal of the Arkansas Academy of Science

No abstract provided.

Specific-Heat Study Of The Anomalous Quantum Limit Of (Tmtsf)2clo4, Nathanael A. Fortune, J. S. Brooks, M. J. Graf, G. Montambaux, L. Y. Chiang, Jos A.A.J. Perenboom, D. Althof

Physics: Faculty Publications

We report calorimetric measurements of the organic conductor (TMTSF)2ClO4 in the quantum limit. In addition to the field-induced spin-density-wave (FISDW) phases, we have measured the magnetic-field-dependent specific heat associated with the recently discovered reentrant phase. In terms of a semiempirical model, we find that the reentrant transition is second order, but that the electronic density of states is greatly reduced in the reentrant phase. We also observe a specific-heat signal corresponding to the anomalous fast oscillations which are known to coexist with the FISDW phases.

Instrument Matrix Of The Four-Detector Photopolarimeter: Physical Meaning Of Its Rows And Columns And Constraints On Its Elements, R. M.A. Azzam

Electrical Engineering Faculty Publications

The four-detector photopolarimeter (FDP) is an arrangement of four photodetectors for measuring the state of polarization of light. The output current vector I of the FDP is related to the input Stokes vector S by I = AS, where A is the instrument matrix. The rows of A can be viewed as projection operators that determine the output currents of the detectors. This leads to the recognition of four special totally polarized input states, each of which maximizes the output of one detector. The associated four orthogonal states produce minimum signals. Because each detector is absorptive and its output is …

Oxidation-Reduction Behavior Of Undoped And Sr-Doped Lamno3: Defect Structure, Electrical Conductivity, And Thermoelectric Power, J. H. Kuo, Harlan U. Anderson, Don M. Sparlin

Materials Science and Engineering Faculty Research & Creative Works

Seebeck coefficient and electrical conductivity measurements were performed for undoped and Sr-doped LaMnO₃ as a function of temperature and oxygen partial pressure. The results of electrical conductivity showed typical p-type behavior. As reduction proceeded, the electrical conductivity of these LaMnO₃-based perovskites decreased with P 1 4O₂. The analysis of the electrical conductivity data was performed by extending the defect model from a previous thermogravimetric (TG) study. The measured Seebeck coefficients were found to be positive except for the most reducing conditions when the decomposition into multiple phases occurred. The Heikes formula was adopted to interpret …

Enhanced Radiative Auger Emission From Lithiumlike S13+16, E. M. Bernstein, M. W. Clark, C. S. Oglesby, J. A. Tanis, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, B. M. Johnson, K. W. Jones

Physics Faculty Research & Creative Works

The radiative Auger emission (RAE) from 0.946.25-MeV/u ₁₆S¹³⁺ (lithiumlike) projectiles excited in collisions with He target atoms has been measured. For these highly stripped ions the intensity of RAE photons relative to K x-ray emission is enhanced by about a factor of five compared with theoretical calculations and an earlier experimental measurement for S ions with few electron vacancies. The enhancement of RAE for S¹³⁺ is qualitatively similar to results reported previously for lithiumlike ₂₃V²⁰⁺; however, some differences between S and V are evident. © 1990 The American Physical Society.

Physical Properties Of Coarse Aerosol Particles And Haze Elements In Polluted Urban-Marine Environment, Josef Podzimek

Physics Faculty Research & Creative Works

Measurements of coarse particles (with r ≥ 1.0 μm) with the aid of a cascade impactor and of particle (droplet) identification in sensitized gelatine layers reveal their mean concentration of about 1.5 cm-3 during the months of May and June 20 km west from Napoli in Italy. Haze particles (droplets) are usually featured by insoluble core and many small particles deposited on their surface. Sea salt aerosol does not play a dominant role in the haze element formation at this site of measurement. © 1990.

Binary Nucleation Of Ethanol And Water, John L. Schmitt, J. Whitten, G. W. Adams, R. A. Zalabsky

Physics Faculty Research & Creative Works

The authors have used a fast expansion cloud chamber to measure binary homogeneous nucleation rates in several ethanol-water mixtures as a function of temperature, ethanol and water activities and nucleation rate. Data (ethanol and water activities) are presented for a range in nucleation rate from 10 3 to 105 drops/cm3 s from 263 to 293 K for mixtures having mole ratios (ethanol/water) of 10, 4, 0.1, 0.01, and 0.001. A comparison of the extensive data set to other data in the literature shows good agreement. We find current theory, as expected, is unable to accurately predict the data at low …

The Effects Of Prisms Learning Cycle Strategies On Achievement, Integrated Process Skills, And Attitudes Towards Physics Of High School Physics Students When Referenced To Kolb’S Learning Style Inventory, Michael P. Kelly

Dissertations and Theses @ UNI

This study asked the question: Is the gain in physics achievement, process skills, and attitudes toward physics, using the PRISMS teaching strategy, different among high school physics students in the four cognitive learning modes identified by the Kolb Learning Styles Inventory (LSI)? In this study a group of high school physics students were tested for gains in scores in the three areas mentioned in the statement of the problem. This treatment group was taught using PRISMS teaching strategies. Their learning styles were classified according to the Kolb LSI. The procedure followed for this study included administration of the Kolb LSI …

Advanced Infrared Optically Black Baffle Materials, David D. Allred, Ronald D. Seals, C. M. Egert

Faculty Publications

Infrared optically black baffle surfaces are an essential component of many advanced optical systems. All internal surfaces in advanced infrared optical sensors that require stray light management to achieve resolution are of primary concern in baffle design. Current industrial materials need improvements to meet advanced optical sensor systems requirements for optical, survivability, and endurability. Baffles are required to survive and operate in potentially severe environments. Robust diffuse-absorptive black surfaces, which are (1) thermally and mechanically stable to threats of x-ray, launch, and in-flight maneuver conditions, with specific densities to allow an acceptable weight load, (2) handleable during assembly, (3) cleanable, …

Diffuse Absorbing Beryllium Coatings Produced By Magnetron Sputtering, David D. Allred, C. M. Egert

Faculty Publications

Beryllium coatings with varying thicknesses and columnar grain sizes were deposited by low temperature magnetron sputtering and wet chemically etched to enhance diffuse absorption of light. After etching these coatings exhibited a matte black surface finish and low specular reflectance (below 2%) in the IR up to a critical wavelength dependent upon the original grain size of the coating. Extremely thick coatings (350 µm) with original grain sizes of 10 to 12 µm were produced which exhibited specular reflectances below 0.5% up to 50 µm wavelength and a Lambertian BRDF at 10.6 µm averaging 4.3x10-3 ster-1. Scanning electron micrographs are …

Application Of The Results Of Carbon Pellet Modeling To The Problem Of Plasma Penetration, L. L. Vahala, A. G. El Cashlan, G. A. Gerdin, P. B. Parks

Electrical & Computer Engineering Faculty Publications

The assumptions of the evaporation model for low-Z pellets interacting with magnetic fusion plasmas developed by Parks are tested. These assumptions are that the vapor density profile in the region adjacent to the pellet surface falls off with radial distance as r^-α , where 5 <α<6, and that the ionization time for the transition between charge states ז_f (i.e., for r < ~3 sonic radii). The first assumption is tested by solving a two-parameter eigenvalue problem for the evaporation cloud in the region interior to the sonic radius; the results are found to be consistent with the low-Z evaporation model. The second assumption, that ז_zi «ז_f, is tested at the sonic radius using the results from atomic physics and the low-Z evaporation model. It is found that indeed ז_zi «ז_f for plasmas with parameters close to thermonuclear conditions (e.g. CIT), but not for those of smaller Tokamaks such as …

Measurement Of Magnetic Fluctuations By O-X Mode Conversion, L. L. Vahala, G. Vahala, N. Bretz

Electrical & Computer Engineering Faculty Publications

The possibility of measuring magnetic fluctuations in a fusion plasma is considered by examining the O→X mode conversion. Under certain conditions and with good angular resolution, this mode conversion can be attributed to the presence of magnetic fluctuations even though the level of these fluctuations is much lower than that of density fluctuations. Some nonideal effects such as mode polarization mismatch at the plasma edge are also discussed.

Influence Of Copper Doping On The Performance Of Optically Controlled Gaas Switches, St. T. Ko, V. K. Lakdawala, K. H. Schoenbach, M. S. Mazzola

Electrical & Computer Engineering Faculty Publications

The influence of the copper concentration in silicon-doped gallium arsenide on the photoionization and photoquenching of charge carriers was studied both experimentally and theoretically. The studies indicate that the compensation ratio (N_Cu/N_Si) is an important parameter for the GaAs:Si:Cu switch systems with regard to the turn-on and turn-off performance. The optimum copper concentration for the use of GaAs:Si:Cu as an optically controlled closing and opening switch is determined.

A Study Of The Hydration Properties Of Selected Laser Dye Aerosols Including Continuous-Flow Parallel Plate And Alternating-Gradient Thermal Diffusion Cloud Chamber Measurements In The High Supersaturation Regime, Donald E. Hagen, Max B. Trueblood, Darryl J. Alofs

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Hydration Behavior of Aerosols made Up of Various Fluorescent Dyes when Exposed to Water Saturation or Supersaturated Conditions Has Been Studied. Critical Supersaturation Spectra Are Reported. the Dyes Are Found to Behave as High Molecular Weight Ionic Compounds that Obey Kohler Theory. their Relevant Kohler Parameters Are Measured. This Study Makes Use of and Compares Results from the Isothermal Hazecontinuous-Flowand Alternating-Gradient Thermal Diffusion Cloud Chambers. the Ability of the Continuous-Flow Thermal Diffusion Chamber to Operate Correctly at High Supersaturations is Shown. © 1990 Elsevier Science Publishing Co., Inc.

Time And The Physical Universe, Norman E. Ramsey

DSLS 1989-1990

(This information was taken from the Distinguished Scientist Lecture Series Program 1989-1990).

Norman F. Ramsey is the Higgins Professor ofPhysics at Harvard University. He has been a Harvard faculty member since 1947. Norman Ramsey received his A.B. and M.A. from Columbia University and degrees from Cambridge University. In1940 he received aPh.D. from Columbia University for molecular beam studies of rotational magnetic moments of molecules. He was awarded an Sc.D. by Cambridge University in1954 and by Oxford University in1973, as well as honorary D.Sc.'s from Case-Western Reserve University, Middlebury College, and Rockefeller University. After periods at the Carnegie Institution of Washington, …

Accurate Calibration Of The Four-Detector Photopolarimeter With Imperfect Polarizing Optical Elements, R. M.A. Azzam, Ali G. Lopez

Electrical Engineering Faculty Publications

The first three columns of the instrument matrix A of the four-detector photopolarimeter (FDP) are determined by Fourier analysis of the output current vector I(P) as a function of the azimuth angle P of the incident linearly polarized light. Therefore 12 of the 16 elements of A are measured free of the imperfections of the (absent) quarter-wave retarder (QWR). The effect of angular beam deviation by the polarizer is compensated for by taking the average, (1/2) [I(P) + I(P + 180°)], of the FDP output at 180°-apart, optically equivalent, angular positions of the polarizer. The remaining fourth column of A …

Domain Decomposition For Multigrid, Finite Volume Flow Solvers, Victor Robert Lessard

Mechanical & Aerospace Engineering Theses & Dissertations

Computing the flow fields about three-dimensional complex configurations accurately becomes a difficult task, if it is attempted to generate a single, body fitted grid with proper clustering. The domain decomposition methods, which divide the computational domain into less complex subdomains, are extensively used to decrease the grid generation workload. A domain decomposition technique also allows the use of different solution methods for different subdomains. The objective of this work is to develop a domain decomposition method via overlapping/embedding the component grids, which is to be used by upwind, multigrid, finite volume solution algorithms. A computer code, given the name MaGGiE, …