Physical Sciences and Mathematics Commons^™

Electroproduction Of Omega (783) Mesons Using Clas At Jefferson Lab, Alan Clayton Coleman

Dissertations, Theses, and Masters Projects

Electroproduction of omega(783) mesons from a proton target has been measured in a search for so called "missing baryon resonances". A 4.0 GeV electron beam was used. The scattered electrons were measured in coincidence with the recoiling proton and the positive pion from the omega decay. Missing mass techniques were applied to identify the omega in the final state, and to reduce the rho(770) contribution. The data show the omega very clearly on a smooth background originating predominantly from three-pion phase space. Yields have been extracted, and the W and t dependencies determined. The t dependence is mostly monotonic for …

Studies On The Amylolytic Breakdown Of Damaged Starch In Cereal And Non-Cereal Flours, Karen Bailey

Masters

The term starch damage refers to a number of changes to the starch granule structure, which are detectable by different analytical techniques. Damaged starch is the substrate for amylases, which in turn provides carbohydrates that are used in the production of certain foods and food ingredients; as a result, therefore, determination of levels in flours is a procedure carried out routinely by many manufacturers of starch based products. Enzymatic assay methods emulate the susceptibility of damaged starch granules to enzymatic attack. The first aim of this study was to evaluate enzymatic methods(1,2) to determine damaged starch in wheat flours and …

Monitoring The 1996 Drought Using The Standardized Precipitation Index, Michael J. Hayes, Mark D. Svoboda, Donald A. Wilhite, Olga V. Vanyarkho

Drought Mitigation Center: Faculty Publications

Droughts are difficult to detect and monitor. Drought indices, most commonly the Palmer Drought Severity Index (PDSI), have been used with limited success as operational drought monitoring tools and triggers for policy responses. Recently, a new index, the Standardized Precipitation Index (SPI), was developed to improve drought detection and monitoring capabilities. The SPI has several characteristics that are an improvement over previous indices, including its simplicity and temporal flexibility, that allow its application for water resources on all timescales. In this article, the 1996 drought in the southern plains and southwestern United States is examined using the SPI. A series …

Photochemical And Thermal Reactions Of Nitrous Acid In A Benzene Matrix, Ethan Schrum '99

Honors Projects

The photodegradation of nitrous acid in the troposphere is an initiation step in the formation of photochemical smog. NOx emissions from internal combustion engines react with atmospheric water vapor during sundown hours to form nitrous acid. Daytime sunlight cleaves nitrous acid into OB and NO radicals, which attack hydrocarbons emitted by industry to form the constituents of photochemical smog. In order to increase our understanding of these reactions, we have studied them in the liquid phase. Aqueous nitrous acid was extracted into a liquid benzene matrix to form a clear solution of approximately 0.075 M nitrous acid in benzene, which …

The Hofmann Rearrangement Using Household Bleach: Synthesis Of 3-Nitroaniline, Ram Mohan, Keith Monk

Scholarship

No abstract provided.

Caribbean: Online Bibliography Environmental History Of Latin America, Darcy C. Del Bosque

Library Faculty Publications

This is an annotated bibliography of articles, conference proceedings, reports, and books.

What Does Smart Growth Mean For Housing?, Karen A. Danielsen, Robert E. Lang, William Fulton

Public Policy and Leadership Faculty Publications

Barely noticed amid the returns from the 1998 midterm elections was a quiet revolution that goes to the heart of how and where Americans live. While most news accounts focused on the high-profile candidate elections, voters across the nation-in Democratic and Republican areas alike-approved more than 160 state and local ballot measures intended to preserve open space and limit urban sprawl.

The coalition forming around the idea of limiting sprawl includes environmentalists, farmers, big-city mayors, and some developers. But perhaps most important, the so-called "smart growth" movement also includes many suburban voters who are fed up with growth. For example, …

Speed Range For Breakdown Waves, Mostafa Hemmati, Eric L. George, Frances Terry

Journal of the Arkansas Academy of Science

Considering the electrons as the main element in breakdown wave propagation and using a one-dimensional, steady-state, three-fluid, hydrodynamical model, previous investigations have resulted in the completion of a set of equations for conservation of mass, momentum, and energy. We will use the terms proforce and antiforce waves, depending on whether the applied electric field force on electrons is with or against the direction of wave propagation. In the case of antiforce waves, the electron gas temperature and therefore the electron fluid pressure is assumed to be large enough to sustain the wave propagation down the discharge tube. For strong discontinuity …

Statistical Analysis Of Climatic Variables In The Arkansas-Red River Basin, Felix Tendeku

Journal of the Arkansas Academy of Science

Surface meteorological data for the Arkansas-Red River basin are analyzed in order to provide statistical data for modeling and simulation of climatic trends within the basin. The variables studied are the ambient temperature, temperature range and precipitation. Daily and monthly mean values, spatial and seasonal variations, and frequency distributions are determined.

Critical Adsorption Near Edges, Andreas Hanke, M. Krech, F. Schlesener, S. Dietrich

Physics and Astronomy Faculty Publications and Presentations

Symmetry breaking surface fields give rise to nontrivial and long-ranged order parameter profiles for critical systems such as fluids, alloys, or magnets confined to wedges. We discuss the properties of the corresponding universal scaling functions of the order parameter profile and the two-point correlation function, and determine the critical exponents η∥ and η⊥ for the so-called normal transition.

Food Habits And Diet Overlap Of Age-1 And Older Walleye And White Bass In Lake Poinsett, South Dakota, Andrew B. Starostka

Electronic Theses and Dissertations

White bass Marone chysops and walleye Stizostedion vitreum coexist in several of the large glacial lakes in eastern South Dakota. I collected age-1 and older white bass and walleye in Lake Poinsett, South Dakota during May, July and September, 1998 to determine food habits and diet overlap using percent by weight to describe diets and Schoener's index (Cxy) to determine diet overlap. Macroinvertebrates were common prey items for white bass in all length groups during all sample dates. The primary macroinvertebrates consumed by white bass were corixids, amphipods and dipterans. Fish, as a group, were second in diet importance over …

A Quantile‐Based Approach For Relative Efficiency Measurement, Paul M. Griffin, Paul H. Kvam

Department of Math & Statistics Faculty Publications

Two popular approaches for efficiency measurement are a non‐stochastic approach called data envelopment analysis (DEA) and a parametric approach called stochastic frontier analysis (SFA). Both approaches have modeling difficulty, particularly for ranking firm efficiencies. In this paper, a new parametric approach using quantile statistics is developed. The quantile statistic relies less on the stochastic model than SFA methods, and accounts for a firm's relationship to the other firms in the study by acknowledging the firm's influence on the empirical model, and its relationship, in terms of similarity of input levels, to the other firms.

Bayes Estimation Of A Distribution Function Using Ranked Set Samples, Paul H. Kvam, Ram C. Tiwari

Department of Math & Statistics Faculty Publications

Aranked set sample (RSS), if not balanced, is simply a sample of independent order statistics generated from the same underlying distribution F. Kvam and Samaniego (1994) derived maximum likelihood estimates of F for a general RSS. In many applications, including some in the environmental sciences, prior information about F is available to supplement the data-based inference. In such cases, Bayes estimators should be considered for improved estimation. Bayes estimation (using the squared error loss function) of the unknown distribution function F is investigated with such samples. Additionally, the Bayes generalized maximum likelihood estimator (GMLE) is derived. An iterative scheme based …

Double Electron Removal And Fragmentation Model Of The [Formula Presented] Molecule By Highly Charged Ions, C. J. Wood, Ronald E. Olson

Physics Faculty Research & Creative Works

A five-body classical trajectory Monte Carlo model has been developed to study double electron removal from H₂ by collisions with highly charged ions at impact energies ranging from 1 eV/u to 1 GeV/u. The longitudinal and transverse final-state correlation between ejected electrons is calculated for double ionization of H₂ by impact of Se²⁸⁺ at 3.6 MeV/u and U⁹²⁺ at 1 GeV/u; the electron-electron interaction is dynamically included during the collision when one of the electron’s total energy becomes positive. Relativistic corrections are incorporated to reflect the Lorentz contraction of the projectile’s electric field. The cross-section dependence …

Five-Body Calculations Of [Formula Presented] Fragmentation By [Formula Presented] Impact, C. R. Feeler, Ronald E. Olson, Robert D. Dubois, T. Schlathölter, O. Hadjar, R. Hoekstra, R. Morgenstern

Physics Faculty Research & Creative Works

A five-body classical trajectory Monte Carlo model has been developed to study fragmentation of diatomic molecules after double electron removal by highly charged ion impact. A systematic study of the final-state deuteron energy and momentum spectra has been conducted for Xe¹⁹⁺ + D₂ collisions at impact energies ranging from 1 eV/u to 100 keV/u. At the highest projectile energies, the fragment energies and momenta are determined by the Coulomb explosion of the doubly ionized molecule via the known Franck-Condon transition for the isolated molecule. The deuterons are emitted back-to-back with nearly equal energies. At the lowest projectile energies, …

Classification Of Great Basin Plant Communities Occuring On Dugway Proving Ground, Utah, Verl Emrick, Alison Hill

Elusive Documents

No abstract provided.

Ontogenetic Habitat Shifts Of Juvenile Bear Lake Sculpin, J. Ruzycki, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Bear lake sculpin Cottus extensus exhibit ontogenetic habitat shifts during their initial year of life. Distribution and habitat switching was measured with bimonthly bottom-trawl surveys repeated throughout the summer. Patterns of daily growth increments on otoliths were used to measure the history of habitat residence, individual size at the time of the habitat switch, and habitat-specific growth rates. Laboratory experiments and known-age fish confirmed daily increment formation of otoliths. After dispersing during an initial pelagic larval stage, postlarval juveniles settled in both the warm, food-rich littoral zone and the cold, unproductive profundal zone. During summer, initial profundal-zone inhabitants underwent a …

Under-Ice Diel Vertical Migrations Of Oncorhynchus Nerka And Their Zooplankton Prey, G. B. Steinhart, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We used stationary hydroacoustics and measures of environmental conditions (water temperature, dissolved oxygen, light levels, and zooplankton) to determine what factors, foraging or predation risk, influenced diel vertical migrations of Oncorhynchus nerka during winter in three high-mountain lakes. The Sawtooth Valley lakes are deep, oligotrophic, glacial lakes located in central Idaho, U.S.A., and historically contained populations of anadromous O. nerka. In general, low light intensities limited foraging opportunities of O. nerka under ice, especially at night. In Stanley Lake, O. nerka underwent diel vertical migrations to exploit available light to feed. Oncorhynchus nerka occupied shallow water at night, where there …

Robust I-Sample Analysis Of Means Type Randomization Tests For Variances, Anthony Joseph Bernard

UNF Graduate Theses and Dissertations

The advent of powerful computers has brought about the randomization technique for testing statistical hypotheses. Randomization tests are based on shuffles or rearrangements of the (combined) sample. Putting each of the I samples "in a bowl" forms the combined sample. Drawing samples "from the bowl" forms a shuffle. Shuffles can be made with or without replacement.

In this thesis, analysis of means type randomization tests will be presented to solve the homogeneity of variance problem. An advantage of these tests is that they allow the user to graphically present the results via a decision chart similar to a Shewhart control …

An Efficient Implementation Of The Transportation Problem, Alissa Michele Sustarsic

UNF Graduate Theses and Dissertations

The transportation problem is a special type of linear program in which the objective is to minimize the total cost of shipping a single commodity from a number of sources (m) to a number of destinations or sinks (n).

Because of the special structure of the transportation problem, a special algorithm can be designed to find an optimal solution efficiently. Due to the large amount of information in the problem, judicious storage and management of the data are essential requirements of any viable implementation of the transportation algorithm.

Using sparse matrix techniques to store the solution …

Adaptive User Models For The Design Of Intelligent User Interfaces, Lisa Martha Hunt

UNF Graduate Theses and Dissertations

The objective of this research is to determine the effects over time of a dynamic system that adapts itself to a user's current state of expertise, in terms of the application domain, by constantly monitoring the user throughout use of the system, placing them in appropriate user models when this expertise has changed.

A dynamic system, named ER-by-Design version 2.0, is presented, consisting of an inference component, a help system, a help/assistance screen, and user models. The user models are responsible for adapting the system interface to the level of expertise of the user. The system monitors and analyzes a …

Synchrotron X-Ray Diffraction Of Layering Transitions Of Multilayer Nitrogen Physisorbed On Graphite, T. E. Burns, John R. Dennison, S. N. Ehrlich

All Physics Faculty Publications

We use synchrotron x-ray diffraction for structural analysis of the behavior of multilayer nitrogen films physisorbed on graphite foam. We provide structural information and concentrations of 2D and 3D solid phases at a coverage of Θ = 8 ML (Θ / 1 ML for a %3 x %3 structure) for temperatures from below the bulk α-ß transition temperature [T_α-ß = 34 " 0.5 K] to above the bulk triple point [T_tp = 63 K]. Our data indicate layering begins near T_α-ß, with subsequent layering occurring as the temperature is raised; all bulk nitrogen forms disordered film …

Null Geodesics In The Alcubierre Warp Drive Spacetime: The View From The Bridge, Chad Clark, William A. Hiscock, Shane L. Larson

All Physics Faculty Publications

The null geodesic equations in the Alcubierre warp-drive spacetime are numerically integrated to determine the angular deflection and redshift of photons which propagate through the distortion of the `warp-drive' bubble to reach an observer at the origin of the warp effect. We find that for a starship with an effective warp speed exceeding the speed of light, stars in the forward hemisphere will appear closer to the direction of motion than they would to an observer at rest. This aberration is qualitatively similar to that caused by special relativity. Behind the starship, a conical region forms from within which no …

Midisuperspace Models Of Canonical Quantum Gravity, Charles G. Torre

All Physics Faculty Publications

A midisuperspace model is a field theory obtained by symmetry reduction of a parent gravitational theory. Such models have proven useful for exploring the classical and quantum dynamics of the gravitational field. I present three recent classes of results pertinent to canonical quantization of vacuum general relativity in the context of midisuperspace models. (1) I give necessary and sufficient conditions such that a given symmetry reduction can be performed at the level of the Lagrangian or Hamiltonian.(2) I discuss the Hamiltonian formulation of models based upon cylindrical and toroidal symmetry. In particular, I explain how these models can be identified …

The Conductor-Dielectric Junctions In A Low Density Plasma, B. V. Vayner, J. T. Galofaro, D. C. Ferguson, Win De Groot, Clint Thomson, John R. Dennison, Robert Davies

All Physics Faculty Publications

A conductor-dielectric junction exposed to the space environment is a frequent spacecraft design feature. Due to spacecraft charging and/or solar array operation, the conductor can acquire a high potential with respect to the surrounding plasma. If this potential is positive the insulators adjacent to exposed conductors can collect current as if they were conductors themselves. This phenomenon, called snapover, results in a substantial increase in current collection, and may even result in a glow discharge if the potential is high enough. If a conductor has a negative potential, arcing can occur at the site of a junction. Both of these …

Constructing A Portable Sundial, Michelle B. Larson

All Physics Faculty Publications

Throughout history people have used shadows and sundials to measure the passage of time. This article describes how to construct a personal sundial that can be worn as a necklace or carried as a key chain. The activity is easily adaptable for grade levels elementary through high school. The instructions can be scaled for a schoolyard project. We’ve found sundial construction to be a terrific project that not only encourages students to investigate movement of the Sun in the sky, but also allows them to practice their math skills.

Effects Of Magnetospheric Precipitation And Ionospheric Conductivity On The Ground Magnetic Signatures Of Traveling Convection Vortices, Lie Zhu, Robert W. Schunk, Jan Josef Sojka

All Physics Faculty Publications

By using an improved TCV model (Zhu et al., 1997), a quantitative study of the effects of magnetospheric precipitation and ionospheric background conductivity on the ground magnetic signatures of traveling convection vortices (TCVs) has been conducted. In this study the localized conductivity enhancement associated with the TCVs is present and the ratio of the Hall and Pedersen conductances vary both spatially and temporally according to the hardness of the TCV precipitation. It is found that a strong conductivity enhancement associated with hard TCV precipitation can significantly distort the TCV current closure in the ionosphere and lead to ground magnetic disturbance …

Functional Evolution Of Free Quantum Fields, Charles G. Torre, Madhavan Varadarajan

All Physics Faculty Publications

We consider the problem of evolving a quantum field between any two (in general, curved) Cauchy surfaces. Classically, this dynamical evolution is represented by a canonical transformation on the phase space for the field theory. We show that this canonical transformation cannot, in general, be unitarily implemented on the Fock space for free quantum fields on flat spacetimes of dimension greater than 2. We do this by considering time evolution of a free Klein-Gordon field on a flat spacetime (with toroidal Cauchy surfaces) starting from a flat initial surface and ending on a generic final surface. The associated Bogolubov transformation …

Effects Of Spacecraft Potential On Secondary Electron Yields In Geosynchronous Orbit, Neal E. Nickles

All Physics Faculty Publications

Surface charging due to interactions with the earth=s plasma is a hazard for orbiting spacecraft. Secondary electron (SE) emission is an important physical process in spacecraft charging. Current spacecraft charging models do not consider the SE energy or angular distributions and their implications for estimating the return of SE to the spacecraft. Comprehensive work on the application of SE energy and angular distributions to spacecraft charging has been published [Nickles et al., 1999] and part of that work is summarized here. The application of SE energy distributions to the case of positive charging in geosynchronous orbit is discussed and shown …

Geology Of The Oquirrh Mountains, Utah, United States Geological Survey

All U.S. Government Documents (Utah Regional Depository)

The Oquirrh Mountains are located in north-central Utah, immediately south of the Great Salt Lake, in the easternmost part of the Basin and Range physiographic province. The range consists of northerly-trending aligned peaks 56 kilometers long flanked on the west by Tooele and Rush Valleys and on the east by Jordan and Cedar Valleys. The range hosts several of the more prominent base- and precious-metal and desseminated-gold mining areas in the western United States. The 130-year old Bingham porphyry copper mining district, which is of world-class magnitude in the central part of the range, is still active. The Mercur mining …