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 …

Water Current, Volume 31, No. 4, August 1999

Water Current Newsletter

From Buffalo to Bottled Water, Summer Water Tour Attracts Newcomers
From the Director: Nebraska's Number One Resource? You Be the Judge
1999 Nebraska Water Legislation
Seventh Annual Festival of Color Will be August 28, Near Mead
Two Join Water Sciences Lab Staff
Water News Briefs
Overview of Vision Statements Available
The Value of Water
1999 USBR Hydrologic Modeling Inventory (HMI)
Understanding and Addressing Groundwater Risks
Water Center Faculty Responds to Request from "Down Under"

Charge Dynamics In The Half-Metallic Ferromagnet Cro2, E. J. Singley, Christopher P. Weber, D. N. Basov, A. Barry, J. M. D. Coey

Physics

Infrared spectroscopy is used to investigate the electronic structure and charge carrier relaxation in crystalline films of CrO₂ which is the simplest of all half-metallic ferromagnets. Chromium dioxide is a bad metal at room temperature but it has a remarkably low residual resistivity (<5 >μΩ cm) despite the small spectral weight associated with free carrier absorption. The infrared measurements show that low residual resistivity is due to the collapse of the scattering rate at ω<2000 >cm^-1. The blocking of the relaxation channels at low v and T can be attributed to the unique electronic structure of a …

Central Platte River Forests: Breeding Birds And Woody Vegetation, Barbara K. Good

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

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 …

Twist Modulated Phases In Chiral Smectic Liquid Crystals, Jonathan J. Stott, Rolfe G. Petschek

Faculty Scholarship

By considering short period helical planar modulations about the layer normal, we construct a model free energy for the ferriclinic phases observed in chiral smectic liquid crystals. We then use this free energy to construct the phase diagram for our model. The resulting phases are compared with the experimentally observed smectic-C* subphases (ferroclinic, antiferroclinic, and heliclinic). A strong coupling is found between the ferroclinic q=2Ï€/a and the heliclinic q=2Ï€/3a modes. This coupling was not considered in previous models. The resulting additional stability of this "locked in" phase is discussed.

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 …

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 …

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 …

Positive Solutions To Semilinear Problems With Coefficient That Changes Sign, Nguyen Phuong Cac, Juan A. Gatica, Yi Li

Mathematics and Statistics Faculty Publications

No abstract provided.

Mobile Agents And The Future Of The Internet, David Kotz, Robert S. Gray

Dartmouth Scholarship

Use of the Internet has exploded in recent years with the appearance of the World-Wide Web. In this paper, we show how current technological trends may lead to a system based substantially on mobile code, and in many cases, mobile agents. We discuss several technical and non-technical hurdles along the path to that eventuality. It seems likely that, within a few years, nearly all major Internet sites will be capable of hosting and willing to host some form of mobile code or mobile agents.

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.

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.

Artificial Intelligence Approach To Analyzing The Bullwhip Effect In Supply Chains, C. Qing, Keng Siau

Research Collection School Of Computing and Information Systems

Supply chain management critically affects businesses’ abilities to obtain and sustain competitive advantages. The bullwhip effect, however, presents a challenge for successful supply chain management by amplifying demands in the supply chains. This paper presents a systematic approach to tackle the issue of bullwhip effect. Firstly, we define the supply chain under a multiagent framework. Secondly, the group problem solving paradigm, which is a rule learning approach, is proposed to enhance the decision making process within the supply chain framework. The group problem solving paradigm is also suggested as a means to alleviate the bullwhip effect. The paper concludes with …

Modeling Macrophytes Of The Columbia Slough, Oregon, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. It is a eutrophic water body susceptible to algae blooms and crashes and periods of high pH which violate water quality standards. High nutrient loads from groundwater principally controls algae productivity. Past structural changes to the Columbia Slough have included filling of wetlands and lakes and the construction of levees, dikes, culverts and irrigation channels. These changes have altered the natural flow dynamics creating an environment more conducive to eutrophication. …

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, …

Avian Communities Of Large Reclaimed Mine Grasslands In Southwestern Indiana, Travis L. Devault

All-Inclusive List of Electronic Theses and Dissertations

Many bird species native to the tallgrnss prairie region oCthc central U.S. have declined drastically since European settlement due lo the destruction and alteration of grassland habitat. In this study, the breeding bird communities or 21 large reclaimed surface coal mine grasslands in a seven-county area or southwestern Indiana were examined with respect to species and guild composition, density, variation among sites, and grassland size. In addition, the vegetation characteristics of nine large mine grasslands were described and related to the presence and abundance or eight grasslund bird species common to the study areas. The immense size of mine grasslands …

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.

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 …

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 …

A Recurring Improvisational Methodology For Change Management In Erp Implementation, Michelle Sieber, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

Change has become an ongoing phenomenon and business process re-engineering has become a necessity for survival of organizations as we approach the 21st century. As participants in this ever-changing working environment, we must be innovative in managing change as it affects both our professional and personal lives. One of the innovative ways to manage change in the implementation of an enterprise resource planning (ERP) system is to adopt a comprehensive change management methodology. In this research, we propose the use of the recurring improvisational change methodology for managing such change. This research is also aimed at implementing the improvisational change …

Knowledge Sharing With Customers On The Www: Approaches By National Tourism Organizations, Xinran You, Joseph O'Leary, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

The importance of knowledge management has been emphasized increasingly in recent literature. Knowledge has been regarded as the most important corporate asset in an organization (Nonaka and Takeuchi, 1995). But what is knowledge? According to Harris (1996), "when information is combined with context and experience, it becomes knowledge". Hence, knowledge is the integration of information, context, and experience (Ponelis and Fairer-Wessels, 1998). In the tourism context of this paper, there are two components of knowledge: (1) customer knowledge--understanding of customers by marketers that leads to more effective marketing actions; and (2) destination knowledge that either the travelers or travel experts …

Website Design: The Concepts Of Informational And Computational Equivalence, Keng Siau

Research Collection School Of Computing and Information Systems

“To the end users, the user interface is the system.” This slogan has been widely used in human-computer interaction field to stress the importance of user interface design. In the Internet and electronic commerce area, the website is not only the system, but it also projects an image of the organization in cyberspace. The design of websites is central to businesses as they create the first impression of organizations to visitors. For a virtual organization, the website is also the only medium that visitors rely on to form their impression of the organization. In this paper, we look at theories …

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 …

The Salinity And Hydrology Of The Upper Slab Hut Catchment, R Ferdowsian, A T. Ryder

Resource management technical reports

No abstract provided.

Maritime Pine For Western Australia - Revegetation On Farms Information Kit, David Bicknell, Department Of Conservation And Land Management

Natural resources published reports

Revegetation on farms

The Revegetation on Farms Project and the material in this Information Kit is targeted at the agricultural zone of Western Australia with less than 600 mm rainfall. Some of the information is valid outside this range.

All information is provided in good faith, to help make informed revegetation decisions leading to sustainable land use.

TreeNote No 20 - Weed control in eucalypts and pines

TreeNote No 21 - Insect pests of eucalypts and pines

In search of the perfect pine - David Gough (Article)

Farming carbon - Syd Shea (Article)

Science And Security Watch: A Threat To The United States From Foreign Graduate Students Training In Physics?, Ibpp Editor

International Bulletin of Political Psychology

This article critiques concerns of some United States (US) security analysts that foreign graduate students in physics who train at universities within the US present security vulnerabilities for the US.

The Skyrme Model For Baryons, Joseph Schechter, H. Weigel

Physics - All Scholarship

We review the Skyrme model approach which treats baryons as solitons of an effective meson theory. We start out with a historical introduction and a concise discussion of the original two flavor Skyrme model and its interpretation. Then we develop the theme, motivated by the large N_C approximation of QCD, that the {\it effective} Lagrangian of QCD is in fact one which contains just mesons of all spins. When this Lagrangian is (at least approximately) determined from the meson sector it should then yield a zero parameter description of the baryons. We next discuss the concept of chiral symmetry and …