Physical Sciences and Mathematics Commons^™

Production And Annealing Of Electron Irradiation Damage In Zno, David C. Look, D. C. Reynolds, Joseph W. Hemsky, R. L. Jones, J. R. Sizelove

Physics Faculty Publications

High-energy (>1.6 MeV) electrons create acceptors and donors in single-crystal ZnO. Greater damage is observed for irradiation in the [0001] direction (Zn face) than in the [000] direction (O face). The major annealing stage occurs at about 300–325 °C, and is much sharper for defects produced by Zn-face irradiation, than for those resulting from O-face irradiation. The defects appear to have a chain character, rather than being simple, near-neighbor vacancy/interstitial Frenkel pairs. These experiments suggest that ZnO is significantly more “radiation hard” than Si, GaAs, or GaN, and should be useful for applications in high-irradiation environments, such as electronics …

Gas Turbine Spray Dynamics And Combustion Simulation Design, Chenn Zhou, Sanford Fleeter, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

A Note On The Aymptotic Behavior Of The Heights In B-Tries For B Large, Charles Knessl, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

An Agent-Based Netcentric Framework For Multidisciplinary Problem Problem Solving Environments (Mpse), S. Markus, Elias N. Houstis, A. C. Catlin, John R. Rice, P. Tsompanopoulou, D. Gottfried, Ke Su

Department of Computer Science Technical Reports

No abstract provided.

Soliton Evolution And Radiation Loss For The Sine-Gordon Equation , N. F. Smyth, Annette L. Worthy

Faculty of Informatics - Papers (Archive)

An approximate method for describing the evolution of solitonlike initial conditions to solitons for the sine-Gordon equation is developed. This method is based on using a solitonlike pulse with variable parameters in an averaged Lagrangian for the sine-Gordon equation. This averaged Lagrangian is then used to determine ordinary differential equations governing the evolution of the pulse parameters. The pulse evolves to a steady soliton by shedding dispersive radiation. The effect of this radiation is determined by examining the linearized sine-Gordon equation and loss terms are added to the variational equations derived from the averaged Lagrangian by using the momentum and …

Near-Threshold Measurement Of Integrated Stokes Parameters For Kr Excited By Polarized Electrons, B. G. Birdsey, H. M. Al-Khateeb, M. E. Johnston, T. C. Bowen, Timothy J. Gay, V. Zeman, K. Bartschat

Timothy J. Gay Publications

We have made high-accuracy measurements of the integrated Stokes parameters for resonance fluorescence from polarized electron-impact excitation of the ⁴p⁵5p[5/2] ³D₃ and ⁴p⁵5p [5/2] ³D₂ states of Kr. We report measurements in the region within 0.6 eV of threshold, which is below the first cascade threshold. We also present theoretical calculations of these Stokes parameters using a recently developed relativistic Breit-Pauli Rmatrix code. In well LS-coupled systems, nonzero values of the integrated Stokes parameter P₂ signal relativistic effects (like continuum spin-orbit coupling, i.e., Mott scattering). …

41st Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 41st annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 1-5, 1999.

Behavior Of Oceanic Crustal Magnetization At High Temperatures: Viscous Magnetization And The Marine Magnetic Anomaly Source Layer, Julie A. Bowles, H. Paul Johnson

Geosciences Faculty Articles

Although the source layer for marine magnetic anomalies has been assumed to be the extrusive basalts of uppermost ocean crust, recent studies indicate that lower crustal rocks may also contribute. Because the temperature at which magnetization of crustal rocks achieves long-term stability is crucial to any source layer contribution, we undertook high-temperature VRM (viscous remanent magnetization) experiments on samples of basalt, dike and gabbroic sections. Samples were heated at temperature intervals up to T_c, while a magnetic field was applied for periods between 6 hours and 28 days. Results show that the dike and gabbro samples achieve maximum …

Dust Emission From Herbig Ae/Be Stars: Evidence For Disks And Envelopes, Anatoly Miroshnichenko, Željko Ivezić, Dejan Vinković, Moshe Elitzur

Physics and Astronomy Faculty Publications

Infrared and millimeter-wave emission from Herbig Ae/Be stars has produced conflicting conclusions regarding the dust geometry in these objects. We show that the compact dimensions of the millimeter-wave-emitting regions are a decisive indication for disks. But a disk cannot explain the spectral energy distribution unless it is embedded in an extended envelope that (1) dominates the IR emission and (2) provides additional disk heating on top of the direct stellar radiation. Detailed radiative transfer calculations based on the simplest model for envelope-embedded disks successfully fit the data from UV to millimeter wavelengths and show that the disks have central holes. …

The Prairie Naturalist Volume 31, No.3 September 1999

The Prairie Naturalist

HANTA VIRUS INFECTION IN NORTH DAKOTA SMALL MAMMALS: 1994,1995 ▪ R. W. Seabloom, J. J. Feist, and S L. McDonough

AMERICAN WOODCOCK IN COLORADO ▪ C. E. Braun

AVIFAUNA OF AN EARLY SUCCESSIONAL HABITAT ALONG THE MIDDLE MISSOURI RIVER ▪ D. L. Swanson

REPRODUCTIVE STATUS OF FLEA BEETLES IN NORTH DAKOTA AND SOUTH DAKOTA ▪ M. A. Brinkman and S. A. Clay

NUTRIENT AND ENERGY CHARACTERISTICS OF INVERTEBRATES FROM TWO LOCATIONS IN KANSAS ▪ S. G. Papon, R. J. Robel, and K. Kemp

BOOK REVIEWS

The Wood Warblers ▪ M. G. Knutson

A Fascination With Birds. ▪ J. A. Dechant …

Black Holes And Five-Brane Thermodynamics, Emil Martinec, Vatche Sahakian

All HMC Faculty Publications and Research

The phase diagram for Dp-branes in M theory compactified on T⁴,T⁴/Z₂,T⁵, and T⁶ is constructed. As for the lower-dimensional tori considered in our previous work [E. Martinec and V. Sahakian, Phys. Rev. D 59, 124005 (1999)], the black brane phase at high entropy connects onto matrix theory at low entropy; we thus recover all known instances of matrix theory as consequences of the Maldacena conjecture. The difficulties that arise for T⁶ are reviewed. We also analyze the D1-D5 system on T⁵; we discuss its relation to matrix models …

The Probe, Issue 203 – August 1999

The Probe: Newsletter of the National Animal Damage Control Association

Trappers Association Challenges Ballot Initiatives
Troubling Horizon for NADCA -- Robert H. Schmidt, President
Reed-Joseph International recently announced the availability of CAPA long range pyrotechnic cartridges.
Hazards of Deer Relocation: Mixed Success
Book Review : "Conibear Beaver Trapping in Open Water" by Wesley Murphey. Lost Creek Books, Eugene, Oregon, 1996. 109 pp. Illustrated. ($14.00 postpaid)
Eastern Black Bear Workshop Held in Massachusetts

Cavefish Population Status And Environmental Quality In Cave Springs Cave, Arkansas - Final Report Submitted To Arkansas Natural Heritage Commission, G. O. Graening, Arthur V. Brown

Technical Reports

This report summarizes the continuing effort to monitor environmental quality in the Cave Springs Cave Natural Area and to implement the Ozark Cavefish Recovery Plan. Last year’s report (Brown et al., 1998) identified certain environmental stressors, including a trend over 15 years of increasing nutrient pollution, a low cavefish population count of only 106, and the presence of heavy metals in the cave water and one semi-volatile organic compound (the phthalate DEHP at 500 ppb) in resident crayfish tissue. This year’s monitoring effort demonstrates that fecal coliforms continue to exceed Arkansas State Water Quality Standards (Regulation 2), sometimes by a …

Evaluation Of Raman Spectroscopy And Ruby Piezospectroscopy As Tools For Investigating The Corrosion Of Metallic Alloys, Daniel P. Renusch

Dissertations

Stainless steel system components that operate in high temperature oxidizing environments obtain protection from corrosion by means of thermally grown chromia and alumina scales. Ongoing investigations of protective scales utilize a battery of experimental and theoretical techniques. A technique which has received little attention is Raman scattering. The reason for its limited use has been long data acquisition times required to obtain suitable spectra from thin surface oxides. Because advances in detection systems, namely the multichannel CCD (charge coupled devices), have recently provided dramatic improvement in the sensitivity of Raman scattering experiments, we decided to reevaluate the technique as a …

Configurational Entropy And Collective Modes In Normal And Supercooled Liquids, Ulrich Zürcher, T. Keyes

Physics Faculty Publications

Soft vibrational modes have been used to explain anomalous thermal properties of glasses above 1 K. The soft-potential model consists of a collection of double-well potentials that are distorted by a linear term representing local stress in the liquid. Double-well modes contribute to the configurational entropy of the system. Based on the Adam-Gibbs theory of entropically driven relaxation in liquids, we show that the presence of stress drives the transition from Arrhenius to Zwanzig-Bässler temperature dependence of relaxation times. At some temperature below the glass transition, the energy scale is dominated by local stress, and soft modes are described by …

Hydrogen Dynamics In The Hydrides Of Pr₂Fe₁₇ As Revealed By Mössbauer Spectroscopy, Dimitri Hautot, Gary J. Long, Fernande Grandjean, Olivier Isnard, Salvatore Miraglia

Chemistry Faculty Research & Creative Works

The rhombohedral Pr₂Fe₁₇H_x compounds with the Th₂Zn₁₇ structure have been prepared for x =0-5. Their lattice parameters and Curie temperatures have been determined from powder x-ray diffraction and thermomagnetic measurements, respectively, and their Mössbauer spectra have been measured between 4.2 and 295 K. The Mössbauer spectra for x=0, 1, and 2, obtained between 4.2 and 295 K, and those of Pr₂Fe₁₇H₃, obtained above 90 K, have been analyzed with a seven sextet model, indicative of a basal magnetization in these compounds. The Mössbauer spectra of Pr …

Simple Model For Linear And Nonlinear Mixing At Unstable Fluid Interfaces In Spherical Geometry, John D. Ramshaw

Physics Faculty Publications and Presentations

A simple model was recently described for predicting linear and nonlinear mixing at an unstable planar fluid interface subjected to an arbitrary time-dependent variable acceleration history [J. D. Ramshaw, Phys. Rev. E 58, 5834 (1998)]. Here we present an analogous model for describing the mixing of two adjacent spherical fluid shells of different density resulting from an arbitrary time-dependent mean interface radius R(t). As in the planar case, the model is based on a heuristic expression for the kinetic energy of the system. This expression is based on that for the kinetic energy of a linearly perturbed interface, but with …

Inhibition Of The Aminopeptidase From Aeromonas Proteolytica By Aliphatic Alcohols. Characterization Of The Hydrophobic Substrate Recognition Site, Leila Ustynyuk, Brian Bennett, Tanya Edwards, Richard C. Holz

Physics Faculty Research and Publications

Seven aliphatic and two aromatic alcohols were tested as reporters of the substrate selectivity of the aminopeptidase from Aeromonas proteolytica (AAP). This series of alcohols was chosen to systematically probe the effect of carbon chain length, steric bulk, and inhibitor shape on the inhibition of AAP. Initially, however, the question of whether AAP is denatured in the presence of aliphatic alcohols was addressed. On the basis of circular dichroism (CD), electronic absorption, and fluorescence spectra, the secondary structure of AAP, with and without added aliphatic alcohols, was unchanged. These data clearly indicate that AAP is not denatured in aliphatic alcohols, …

Fisheries Research Report No. 115 - Statistical Analysis Of Gascoyne Region Recreational Fishing Study July 1996, Neil R. Sumner, Richard A. Steckis

Fisheries research reports

A survey of recreational fishers in the Gascoyne region of Western Australia was conducted in July 1996 to provide information required by fisheries managers. Catch rates, attitudinal, demographic and economic information from boat-based and shore-based fishers was collected by Fisheries Officers. Pink snapper (Pagrus auratus) was the primary species caught by boatbased recreational fishers in the region. Various species of whiting were the predominant catch from shore-based anglers. Most fishers interviewed (80%) supported the introduction of an upper limit on the amount of fish and fillets that a person could take away from the Gascoyne region for personal or family …

Polymerization-Induced Phase Separation, J.C. Lee

Faculty Publications

A molecular dynamics simulation is performed to study the kinetics of microphase separation in a polymer-dispersed-liquid-crystal forming process. An equimolar mixture of monomers and liquid crystal molecules are thermalized in a well mixed state. The monomers are then polymerized at the same temperature. The end product is a spanning gel with liquid crystal molecules aggregating in droplets here and there. The peak position of the equal-time structure function suggests that the growth of the droplets may be described with t^-0.23. The small growth exponent is just one of several features which may be attributed to the growing elastic …

The Design And Construction Of An Out-Of-Plane Sensitive Electronic Speckle Pattern Interferometer For Non-Destructive Testing Applications, Alexander Burden

Masters

There are many non-destructive testing (NDT) techniques use din industry, which employ acoustic emission, ultrasound, X-rays and thermography. Optical interferometric methodology is being increasingly used in industry. Electronic Speckle Pattern Interferometry (ESPI) is one of the principal optical interferometric techniques used in NDT to measure deformations. Optical surface metrology offers many advantages over conventional methods. These include greater sensitivity, improved lateral and vertical resolution, non-contact and full field measurement. Conventional methods of NDT however continue to be chosen over ESPI. The objective of this thesis is focused on making ESPI more feasible as a NDT technique for use in industry. …

The Discovery-Oriented Approach To Organic Chemistry. 2. Selectivity In Alcohol Oxidation. An Exercise In 1H Nmr Spectroscopy For Sophomore Organic Laboratories, Ram Mohan, Steven Shadwick

Scholarship

We have developed a simple oxidation experiment that presents the student with a puzzle and is a good exercise in 1H NMR spectroscopy. The experiment, which illustrates the important concept of selectivity in organic synthesis, involves selective oxidation of a mixture of 1-heptanol and 2-heptanol using commercial swimming pool chlorine. 1H NMR analysis of the product mixture allows the student to determine the selectivity exhibited by the reagent.

Equatorial And Low Latitude Thermospheric Winds: Measured Quiet Time Variations With Season And Solar Flux From 1980 To 1990, M. A. Biondi, S. Y. Sazykin, Bela G. Fejer, J. W. Meriwether, C. G. Fesen

Bela G. Fejer

Thermospheric winds have been systematically determined at Arequipa, Peru, and Arecibo, Puerto Rico, from Fabry-Perot interferometer measurements of Doppler shifts in the nightglow 630 nm line. The wind databases (1983 – 1990 at Arequipa and 1980 – 1990 at Arecibo) have been edited to eliminate measurements during geomagnetically disturbed conditions, then sorted by season and solar flux level. Following this, they were averaged to obtain the climatological behavior of the nighttime wind variations at the two locations. A new averaging technique, multivariate regression analysis, has been applied to the data, and the results compared to our prior binning averages. The …

The John Muir Newsletter, Fall 1999, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

TOP "i Volume 9, Number 4 MUIR Fall 1999 VULUMJ, J, HUMbEK 1 i; TALL 1333 newsXhtter John Muir's Struggle in the North: Travels in Alaska and The Cruise of the Corwin by Hal Crimmel, Ph.D. raditionally, Muir's reputation has been that of America's foremost wilderness lover, sage, and advocate, unrelenting in his quest for a pure wilderness experience. "For Muir, wilderness was not a confrontation," Harold Simonson tells us, "but a confirmation."1 This is the Muir that captured the public's imagination, j|e Muir who could write, "The whole wilderness seems to be alive and familiar, full of humanity. The …

Dynamics And Asymptotic Behavior Of The Solutions Of A Nonlinear Differential Equation, Robert Palmer

Masters Theses & Specialist Projects

Initial value problems of the form dx/dt= t xP, x(a) = β are examined, first when p = 2. Applying Euler's method, a numerical approximation technique, when p = 2 for certain initial conditions produces a numerical solution which resembles a bifurcation diagram very similar to that produced by the logistic map. Comparisons of such numerical solutions to the logistic map are made, and a partial explanation of such numerical solutions is given. Then, the exact solution of the initial value problem with p = 2, for which the software package Mathematica 3.0 determines an explicit formula, is analyzed to …

Optical Properties Of Β″-(Et)2sf5ch2cf2so3: A Layered Molecular Superconductor With Large Discrete Counterions, J. Dong, J. L. Musfeldt, J. A. Schlueter, Jack M. Williams, P. G. Nixon, Rolf Walter Winter, Gary L. Gard

Chemistry Faculty Publications and Presentations

We report the polarized infrared and optical reflectance of β″-(ET)₂SF₅CH₂CF₂SO₃ as a function of temperature. This fully organic superconductor displays weakly metallic behavior over the entire temperature range of our investigation. The electronic properties present several unusual features including the lack of a conventional free carrier (Drude) response at low temperature, infrared localization phenomena, and an unexpected temperature dependence of the oscillator strength. Similar behavior is observed in other β and β″ superconductors above Tc, suggesting that this class of compounds is very close to a metal→insulator transition where electronic correlations are important and the Drude response carries very little …

Cluster-Based Database Selection Techniques For Routing Bibliographic Queries, Jian Xu, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

In this paper, we focus on the database selection problem in the context of a global digital library consisting of a large number of online bibliographic servers. Each server hosts a bibliographic database that contains bibliographic records each of which consists of text values for a number of pre-defined bibliographic attributes such as title, author, call number, subject, etc.. Each bibliographic database supports user queries on the bibliographic attributes. Since bibliographic records are relatively small in size, we only consider bibliographic databases that support boolean queries on the bibliographic attributes, and the query results are not ranked. While focusing on …

Analysis Of Galvanized Steel Plates Using Glow Discharge-Atomic Emission Spectrometry, Liang Wang

Masters Theses & Specialist Projects

Combining an intense emission source and a high-speed sputtering source in one, glow discharge atomic emission spectrometer (GD-AES) provides an efficient technique for analyzing surfaces, coatings and bulk solids. The purpose of our work is to explore the optimum lamp operation parameters of SA-2000 for analysis of galvanized steel plate and to investigate the method for qualitatively and quantitatively analyzing the zinc coating. Under the optimum experimental conditions found in our study, which are current of 19-21 mA; voltage of 900-1200 V; pressure 2.0-2.5 torr, the calibration curve is constructed, so that specific zinc concentration can be assign to the …

Fisheries Research Report No. 114 - The Western Australian Scallop Industry, D C. Harris, L M. Joll, R A. Watson

Fisheries research reports

Five separate commercial fisheries target the saucer scallop, Amusium balloti (Bernadi 1861) in Western Australian waters. While the average annual catch from these fisheries is around 600 tonnes of scallop meat, past catches have been highly variable with annual landings ranging from 150 to 4,400 tonnes of meat worth between $2 and $59 million. Consequently, scallops represent one of the larger single-species fisheries operating in Western Australia (WA).

A. balloti has a distribution spanning most of the WA coast, from Broome in the north around to Esperance in the south. Despite this extensive distribution, saucer scallops tend to be restricted …

An Assessment Of The Impact Of Ophthalmia Dam On The Floodplains Of The Fortescue River On Ethel Creek And Roy Hill Stations, A L. Payne, A A. Mitchell

Resource management technical reports

The area surveyed covered all of the floodplains of the Fortescue River, and Jigalong, Jimblebar and Carramulla Creeks which fall within Ethel Creek and Roy Hill stations. Two serious, distinct and largely unrelated environmental problems are evident on the area surveyed. The first problem is longstanding, severe landscape degradation in the form of almost complete loss of perennial vegetative cover and soil erosion (mainly scalding) due to historical overgrazing.