Physical Sciences and Mathematics Commons^™

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.

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 …

Rotational Effects In The Continuous Vacuum-Ultraviolet Fluorescence Spectrum Of H2 Associated With Spontaneous Dissociation, H. Schmoranzer, T. Noll, E. Roueff, H. Abgrall, Ronald James Bieniek

Physics Faculty Research & Creative Works

The effects of rotational-vibrational interaction, and of rotational coupling between the B 2p u+1 and C 2p u1 electronic states, on the B X fluorescence continuum of H2 associated with spontaneous dissociation were investigated spectroscopically using monochromatized synchrotron radiation for selective excitation of rovibronic states. The rotational shifts and perturbations in the modulated continua intensities observed agree well with close-coupling and Jeffreys-Wentzel-Kromers-Brillouin (JWKB) calculations also performed and are explained in terms of nonadiabatic coupling effects and rainbow-interference structures. A straightforward experimental technique is described to detect mixed electronic states. © 1990 The American Physical Society.

Highland: A Graph-Based Parallel Processing Environment For Heterogeneous Local Area Networks, Ralph W. Wilkerson, Douglas E. Meyer

Computer Science Faculty Research & Creative Works

No abstract provided.

Role Of Term Symmetry In E-Completion Procedures, Ralph W. Wilkerson, Blayne E. Mayfield

Computer Science Faculty Research & Creative Works

No abstract provided.

Coatings And Surface Modification By Methane Plasma Polymerization, Chung‐Peng ‐P Ho, H. Yasuda

Chemistry Faculty Research & Creative Works

Polymers formed from plasma‐polymerized methane were employed to modify the surface properties of silicone rubber membrane. Polymers were evaluated based on the energy input parameter W/FM, where W is the discharge power, F is the monomer flow rate, and M is the molecular weight of the monomer. Dealing with the characteristics of plasma polymerization and the deposited polymer film, the effect of pumping rate on deposition rate and the coating thickness, surface energy, and gas permeabilities of methane‐plasma‐polymer‐coated silicone rubber membrane were investigated in three plasma regions. Because more reactive species are expelled at high pumping rates, the monomer‐deficient region …

Plasma Surface Treatment On Nylon Fabrics By Fluorocarbon Compounds, Yu Iriyama, Takeshi Yasuda, D. L. Cho, H. Yasuda

Chemistry Faculty Research & Creative Works

Nylon fabrics were treated by low temperature fluorocarbon plasmas. All of the fluorocarbon plasmas applied altered the surface of nylon fabrics to be hydrophobic and water‐repellent. The durability of hydrophobicity and water repellency was examined by measurements of the water contact angle, the water droplet rolling‐off angle, and the breakthrough water pressure after plasma‐treated fabrics were washed. It was found that the structure of starting fluorocarbon and the plasma energy input were important factors in the durability. After washing, surface dynamics were investigated on different drying conditions. It was found that chemical composition and water repellency were dependent on drying …

Derivatized Cyclodextrins For Normal-Phase Liquid Chromatographic Separation Of Enantiorners, Daniel W. Armstrong, San Chun Chang, Apryll M. Stalcup, Martha L. Hilton, Jo Dee Duncan, James R. Faulkner

Chemistry Faculty Research & Creative Works

Several different derivatized β-cyclodextrins were synthesized and used as chiral stationary phases in normal-phase liquid chromatography. The multiply substituted derivatives were made with acetic anhydride, (R)-and (S)-1-(1-naphthyl) ethyl isocyanate, 2, 6-dimethylphenyl isocyanate, and p-toluoyl chloride. The first successful cyclodextrln-based, normal-phase separation of enantiomers was accomplished on these derivative phases. In contrast to chiral separations on the native β-cyclodextrin stationary phase, the enantiomeric separation mechanism on these new phases is not thought to be dependent on inclusion complexation. The similarities and differences between the derivatized cyclodextrin stationary phases and the cellulosic stationary phases are discussed. © 1990, American Chemical Society. All …

Dawgs - A Distributed Compute Server Utilizing Idle Workstations, Henry Clark, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

A collection of powerful workstations interconnected by a local area network can be utilized as compute servers when left idle by their owners. DAWGS allows users to submit jobs for execution on an idle workstation somewhere on a local area network. DAWGS uses a distributed scheduler and a bidding scheme to determine on which machine to run a process. DAWGS can properly redirect all the I/O of a remotely executing process and can checkpoint and then subsequently restart the process, even if the restart is on a different machine than the checkpoint. Our method is different from other work in …

Computational Intelligence In Cad/Cam Applications, Chaman Sabharwal, Thomas G. Melson, Martin D. Fraser

Computer Science Faculty Research & Creative Works

This paper presents a fundamental, direct, and powerful approach to the surface/surface intersection problem in CAD/CAM applications. The algorithm is designed and implemented in three steps: a) Preprocessing- locate the potentially intersecting sections of the surfaces and decompose the surfaces into surface elements within specified flatness tolerance; b) Intersection- decompose the possibly intersecting pairs of surface elements into continuous surface triangulations to find the approximate intersections between the pairs of surface elements; c) Postprocessing-assemble the intersection primitives into curves of intersection, refine the accuracy of computed intersection points, and compact the intersection curves. This surface/surface intersection algorithm is applicable to …

Dementia In Stroke Survivors In The Stroke Data Bank Cohort: Prevalence, Incidence, Risk Factors, And Computed Tomographic Findings, Thomas K. Tatemichi, Mary A. Foulkes, J. P. Mohr, Jeffrey R. Hewitt, Daniel B. Hier, Thomas R. Price, Philip A. Wolf

Chemistry Faculty Research & Creative Works

We Determined the Prevalence of Dementia in 927 Patients with Acute Ischemic Stroke Aged ≥60 Years in the Stroke Data Bank Cohort based on the Examining Neurologist's Best Judgment Diagnostic Agreement among Examiners Was 68% (K=0.34). of 726 Testable Patients, 116 (16%) Were Demented. Prevalence of Dementia Was Related to Age But Not to Sex, Race, Handedness, Educational Level, or Employment Status Before the Stroke. Previous Stroke and Previous Myocardial Infarction Were Related to Prevalence of Dementia Although Hypertension, Diabetes Mellitus, Atrial Fibrillation, and Previous Use of Antithrombotic Drugs Were Not Prevalence of Dementia Was Most Frequent in Patients with …

Caudate Infarcts, Louis R. Caplan, Edward Feldmann, Jeremy D. Schmahmann, Carlos S. Kase, Phillip B. Gorelick, Daniel B. Hier, Cathy Helgason, George Baquis, John P. Greenberg

Chemistry Faculty Research & Creative Works

Eighteen Patients Had Caudate Nucleus Infarcts (10 Left-Sided; 8 Right-Sided). Infarcts Extended into the Anterior Limb of the Internal Capsule in 9 Patients, and Also the Anterior Putamen in 5 Patients. Thirteen Patients Had Motor Signs, Most Often a Slight Transient Hemiparesis. Dysarthria Was Common (11 Patients). Cognitive and Behavioral Abnormalities Were Frequent, and Included Abulia (10 Patients), Agitation and Hyperactivity (7 Patients), Contralateral Neglect (3 Patients, All Right Caudate), and Language Abnormalities (2 Patients, Both Left Caudate). the Majority of Patients Had Risk Factors for Penetrating Artery Disease. Branch Occlusion of Heubner's Artery, or Perforators from the Proximal Anterior …

Sans From Tetradecylpyridinium Bromide Based Microemulsions, Paul M. Lindemuth, Boualem Hammouda, Raymond L. Venable

Chemistry Faculty Research & Creative Works

Small-angle neutron scattering is used to investigate tetradecyl pyridinium bromide/pentanol/heptane/heavy water microemulsions in the water-in-oil (W/O) microemulsion phase diagram region. The heavy water content is increased while the other components (surfactant, cosurfactant, hydrocarbon) are kept constant. With use of a simple model assuming spherical micelles interacting with a hard-sphere potential (Percus-Yevick model), aggregate sizes and packing fractions have been extracted and found to agree with values determined from the mixing conditions. These experiments clearly show the transition from the single-particle (heavy water + Stern layer droplet) scattering regime at low water concentration to the mixed single/interdroplet scattering regime when the …

Self‐Diffusion Coefficients Of Boc‐Amino Acid Anhydrides Under Conditions Of Solid Phase Peptide Synthesis, Stephen Pickup, Frank D. Blum, Warren T. Ford

Chemistry Faculty Research & Creative Works

No abstract provided.

Relevance Of Enantiomeric Separations In Food And Beverage Analyses, Daniel W. Armstrong, Chau Dung Chang, Wei Yong Li

Chemistry Faculty Research & Creative Works

A series of new derivatized cyclodextrins have been developed for use as chiral stationary phases in capillary gas chromatography. As a result, a large number of the enantiomeric components in food and beverage products can be resolved relatively quickly and easily. The study focuses on compounds other than amino acids (e.g., malic acid, lactic acid, tartaric acid, esters, alcohols, lactone flavors or fragrances, and so on). The ability to separate and quantitate enantiomers at low levels should be useful for detecting adulterated products, for evaluating fermentation processes, and for the accurate characterization of enantiomeric flavor components, growth regulators, pesticides, and …

Distributed Evaluation Of An Iterative Function For All Object Pairs On A Simd Hypercube, Fikret Erçal

Computer Science Faculty Research & Creative Works

An efficient distributed algorithm for evaluating an iterative function on all pairwise combinations of C objects on an SIMD hypercube is presented. The algorithm achieves uniform load distribution and minimal, completely local interprocessor communication.

An Expert System To Convert Knowledge-Based Geological Engineering Systems Into Fortran, Ralph W. Wilkerson, Jill J. Cress

Computer Science Faculty Research & Creative Works

A knowledge-based geographic information system (KBGIS) for geological engineering map (GEM) production was developed in GoldWorks, an expert system development shell. Using this shell, the geological engineer is able to develop a rule base for a particular application that results in a valid GEM. However, this implementation failed as a practical production system due to the excessive execution time required to produce a GEM. To solve this problem, a conversion expert system was developed which accepted, as input, a KBGIS and produced, as output, the equivalent Fortran code. Two major objectives are accomplished as a result of this system: GEN …

Enhanced Polarization Of Electron Spins In He4 By Simultaneous Optical Pumping With Circularly And Linearly Polarized Resonance Radiation, Laird D. Schearer, Padetha Tin

Physics Faculty Research & Creative Works

The polarization of helium (2³S₁) metastable atoms saturates at 50% when the ensemble is optically pumped with the D0 (2³S₁-2³P₀) transition. We have obtained polarizations approaching 100% with a simple, straightforward modification to the conventional experimental arrangement. The addition of a small amount of -polarized D₀ light incident on the cell perpendicular to the defining field direction doubles the polarization produced by circularly polarized + light along the field direction. A simple rate-equation model illustrates the enhancement. © 1990 The American Physical Society.

Experimental Comparison Of Bidding And Drafting Load Sharing Protocols, Andrew Ross, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

In recent years, a dramatic rise in the number of personal workstations interconnected via local area networks has occurred in the workplace. These can be organized as distributed computing systems. The combined computing power of these systems are often greater than mainframes of a decade ago, and usually less expensive. There is a growing interest in harnessing this often-underutilized power. Researchers are focusing their attention on remote execution of processes as one solution. An additional topic of research is to balance a workload among a series of computers. Remote execution is made possible because the distributed operating system provides migration …

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 …

State-Selective Capture In Collisions Between Ions And Ground- And Excited-State Alkali-Metal Atoms, J. Pascale, Ronald E. Olson, C. O. Reinhold

Physics Faculty Research & Creative Works

Total cross sections for state-selective electron capture in collisions between ions and alkali-metal atoms have been calculated by means of a three-body classical-trajectory Monte Carlo (CTMC) method using model potentials to describe the electron ionic-core interactions. Calculations have been performed for Na⁺-Na(28d) collisions and for N⁵⁺ and Ar⁸⁺-Cs(6s) collisions. The collision velocity range corresponds to 0.5vp/ve2, where vp is the projectile velocity in the laboratory frame and ve is the initial orbital velocity of the electron bound to the alkali-metal core. In the case of Na₊+Na(28d) collisions, calculations of the final n,l,m distributions …

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.

Experimentation With Large-Grained Parallelism Using Local Area Networks, Ralph W. Wilkerson, Douglas E. Meyer

Computer Science Faculty Research & Creative Works

HIGHLAND, a distributed-memory parallel processing environment for heterogeneous local area networks, has been developed. Designed as both a teaching and a research tool, its purpose is to provide an effective mechanism by which a number of networked UNIX workstations, dissimilar in both vendor and performance, can be directly manipulated as a single, unified, multiprocessing system. Utilizing the MIT X-windows environment, HIGHLAND supports a highly interactive graphical interface through which a programmer can create, modify, and control complex systems of communicating processes

Molecular Mobility In A Model Polymer Composite, Joan Ethel Gambogi

Masters Theses

"The adsorption of aminoalkysilane coupling agents onto silica surfaces and the interaction of these functional silanes with a bismaleimide and an epoxy resin has been studied using solid-state NMR techniques. ¹³C CP-MAS was used to confirm the bonding between the silence and bismaleimide (BMI) resin and elucidate the nature of the crosslinking reaction of BMI. Deuterated coupling agents were synthesized and adsorbed on silica surfaces. The motional dynamics were probed using deuterium solid-echo NMR. It was determined that the motion of the alky portion of the coupling agents was consistent with gauche migrations (gtt ↔ tig) and pair gauche …

Development Of An Expert System To Convert Knowledge-Based Geological Engineering Systems Into Fortran, Jill J. Cress, Ralph W. Wilkerson

Computer Science Technical Reports

A knowledge-based geographic information system (KBGIS) for geological engineering map (GEM) production was developed in GoldWorks, an expert system development shell. GoldWorks allows the geological engineer to develop a rule base for a GEM application. Implementation of the resultant rule base produced a valid GEM, but took too much time. This proved that knowledge-based GEM production was possible but in GoldWorks implementation failed as a practical production system. To solve this problem, a Conversion Expert System was developed which accepted, as input, a KBGIS and produced, as output, the equivalent Fortran code. This allowed the engineer to utilize GoldWorks for …

The Directed Steiner Problem On Graphs: A Simulated Annealing Approach, Lawrence Joseph Osborne, Billy E. Gillett

Computer Science Technical Reports

The well-known Steiner Problem on Graphs is an NP-complete problem for which there are many heuristic and exact algorithms that are deterministic. In this dissertation a new approach to the directed version of this problem is made by applying the ideas of statistical mechanics through the use of the method of simulated annealing. A version of annealing is developed for the Directed Steiner Problem and compared with one of the best general annealing schemes. Then a comparison is made between simulated annealing and the traditional branch and bound technique. The dual ascent algorithm of Richard T. Wong is used to …

The Role Of Small-Impact-Parameter Electron-Loss Processes On Ion Temperatures Measured By Active-Beam Plasma Diagnostics, A. J.H. Donné, F. J. De Heer, Ronald E. Olson

Physics Faculty Research & Creative Works

The shape of the energy distribution of scattered particles in an active beam scattering experiment can be influenced considerably by the presence of highly charged impurity ions in the plasma. In this work it is shown theoretically that multiply charged impurities have only a small effect on the scattering distribution at low energies (/amu) and at high energies (>75 keV/amu). The effect of the impurities is the most pronounced for energies close to 50 keV/amu. The results of the calculations are in good agreement with experimental results at various energies. Extrapolation to higher beam energies leads to the conclusion …

Study Of The Dependence Of The Electron Emission Spectra On The Projectile Charge In H⁺, He2++He Collisions, C. O. Reinhold, Ronald E. Olson

Physics Faculty Research & Creative Works

The classical trajectory Monte Carlo method (CTMC) has been used to calculate doubly differential ionized-electron cross sections for the impact of He2+ and H+ on He at collision energies of 50 and 100 keV amu-1. The results exhibit the capture to the continuum peak and agree in both shape and magnitude with experimental data. The dependence of the cross sections on the projectile charge ZP is analyzed and it is found to be very asymmetric with regard to the capture to the continuum peak. This behavior is in agreement with very recent experimental data. Large deviations from the Z2P scaling …

Low- And High-Relief Leduc Formation Reefs: A Seismic Analysis, Neil Lennart Anderson, Robert James Sidford Brown, Ronald C. Hinds

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Leduc reefs have grown to widely varying heights and aereal extents along the Rimbey-Meadowbrook trend of central Alberta, resulting in significantly different seismic signatures. Three examples considered in this paper include two high-relief or full reefs from the Leduc-Woodbend field, an atoll and a pinnacle, each around 200 m in height but differing greatly in areal extent, about 100 km² for the atoll and 1 km² for the pinnacle. The third example, a low-relief or basalt reef from the Morinville field, is about 100 m high and 1 km² in areal extent.

The Leduc-Woodbend and Morinville reefs …