Physical Sciences and Mathematics Commons^™

Failure Of The Optical Theorem For Gaussian-Beam Scattering By A Spherical Particle, James A. Lock, Joseph T. Hodges, Gérard Gouesbet

Physics Faculty Publications

It is shown that when an electromagnetic wave with some degree of amplitude rolloff in the transverse direction is scattered by a spherical particle, the optical theorem is not valid. For such shaped beams the extinction cross section may be written as an infinite series in powers of the reciprocal of the beam width. The imaginary part of the forward-scattering amplitude is shown to be the first term in this series. Two approximations to based on the dominance of diffraction in the forward direction for w(0) greater than or similar to a, where w(0) is the beam half-width and a …

Prompt And Sequential Decay Processes In The Fragmentation Of 40 Mev/A 20ne Projectiles, R. J. Charity, L. G. Sobotka, N. J. Robertson, D. G. Sarantites, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, W. C. Hsi, M. J. Huang, W. G. Lynch, C. P. Montoya, Graham F. Peaslee, C. Schwarz, M. B. Tsang

Faculty Publications

The fragmentation of E/A=40 MeV Ne20 projectiles into exit channels containing only p, d, t, He3, α, He6, Li6, and Li7fragments has been investigated. Relative shifts between the average longitudinal velocity of each fragment type were measured with Sn120 and Au197 targets. A post-breakup Coulomb acceleration component of these shifts was isolated. Its magnitude indicates that the projectile broke up while in near contact with the target. On the other hand, correlations between projectile fragments indicate that a significant fraction of these fragments are produced by the sequential decay of long- and short-lived unstable intermediates. A fully sequential decay process, …

The Prairie Naturalist Volume 27, No.4 December 1995

The Prairie Naturalist

NEW DISTRIBUTIONAL RECORDS FOR MAMMALS IN KANSAS · D. W Sparks and J. R. Choate

CLAY-COLORED SPARROWS IN NORTH DAKOTA PARASITIZED BY BROWN-HEADED COWBIRDS ▪ G. P. Romig and R. D. Crawford

A NOTEWORTHY RECORD AND THE BREEDING DISTRIBUTION OF THE BLUE GROSBEAK IN NORTH DAKOTA ▪ L. D. Igl

NEAR LONGEVITY RECORD FOR THE SNOW GOOSE ▪ M T. Koenen and D. M. Leslie, Jr.

COMPARISON OF WATER CONSUMPTION BETWEEN TWO GRASSLAND EMBERIZIDS ▪ J. L. Zimmerman

FACTORS ASSOCIATED WITH DECLINING PROPORTION OF CITIZENS HUNTING IN SOUTH DAKOTA ▪ N. J. Dietz, K. F. Higgins, and R. D. Mendelsohn …

Observation Of Beam-Induced Changes In The Polarization Of Balmer-Α Radiation Emitted Following Beam--Tilted-Foil Transmission, Wang Qi, David D. Allred, Larry V. Knight, Douglas L. Harper, Royal G. Albridge, Norman H. Tolk

Faculty Publications

Measurements of the circular polarization of Balmer-α radiation emitted by excited hydrogen atoms, following the transmission of (20-50)-keV protons through thin, tilted amorphous carbon foils, exhibit markedly unexpected behavior as a function of exposure of the foil to the proton beam. Specifically, the circular polarization changes from an initially well understood tilt-angle dependence to a behavior which, for low tilt angles, gives the opposite handedness of circular polarization from that predicted. In addition, the degree of alignment, indicated by the linear Stokes parameter M/I, is enhanced also as a function of dose. These changes in the tilt-angle dependence of the …

A Neural Network Approach To The Prediction And Confidence Assignation Of Nonlinear Time Series Classifications, Erin S. Heim

Theses and Dissertations

This thesis uses multiple layer perceptrons (MLP) neural networks and Kohonen clustering networks to predict and assign confidence to nonlinear time series classifications. The nonlinear time series used for analysis is the Standard and Poor's 100 (S&P 100) index. The target prediction is classification of the daily index change. Financial indicators were evaluated to determine the most useful combination of features for input into the networks. After evaluation it was determined that net changes in the index over time and three short-term indicators result in better accuracy. A back-propagation trained MLP neural network was then trained with these features to …

The Petrology Of The Precambrian Roof Pendants Thompson Peak, Sawtooth Mountains, Idaho, Susan Denise Anderson

Honors Theses

No abstract provided.

Investigation Of Isolated Sand Shoals On The Inner Shelf Of Virginia Relative To The Potential For Aggregate Mining : Report On Task 4, Possible Physical Impact Of Dredging At Sandbridge Shoal Of The 1993-1995 U. S. Minerals Management Service - Commonwealth Of Virginia Cooperative Project, Jerome P.-Y. Maa

Reports

The Virginia Institute of Marine Science, together with other state agencies, has a continuing interest in preserving the coastline of Virginia, particularly, the Atlantic coastline in the vicinity of the resort city of Virginia Beach. Because a well maintained beach can serve several purposes, e.g., (1) providing public recreational areas, (2) protecting valuable properties that are located near coastline, and (3) reducing the rate of land loss, a great deal of efforts has been devoted to understand the processes that affect the change of shoreline. Among several erosion forces, waves are especially important elements as they can alter the shoreline …

Transitions Between Convective Patterns In Chemical Fronts, Y. Wu, D. A. Vasquez, Boyd F. Edwards, J. W. Wilder

All Physics Faculty Publications

We present a theory for the transition from nonaxisymmetric to axisymmetric convection in iodate-arsenous acid reaction fronts propagating in a vertical slab. The transition takes place away from the onset of convection, where a convectionless flat front becomes unstable to a nonaxisymmetric convective front. The transition is studied by numerically solving a reaction-diffusion equation coupled with nonlinear hydrodynamics in a two-dimensional slab.

Upper-Tropospheric Aerosol Sampled During Project Fire Ifo Ii, Donald E. Hagen, Josef Podzimek, Max B. Trueblood

Physics Faculty Research & Creative Works

Aerosols can play a role in the cloud formation process through the heterogeneous nucleation mechanism, and in turn, once formed, cirrus clouds can impact the ambient aerosol through scavenging and other collection mechanisms. University of Missouri aerosol sampling facilities were employed on aircraft for in situ collection and characterization of the particulates near cirrus cloud level. Tandem differential mobility analyzer and impactor techniques were used to measure aerosol size distribution, hydration capability, and particle composition information. Evidence of aerosol layering was observed near the tropospause, and there was a tendency toward depletion of the ambient aerosol at both ends of …

Mandibular Asymmetry In Unilateral Class Ii Malocclusion : A Cephalometric Study, Raed Z. Moussa

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to evaluate skeletal and dental asymmetry in unilateral class II malocclusion. A study group of 25 unilateral subdivision patients was compared to 25 class I malocclusion patients serving as the control group. Submento-vertical and frontal radiographs were used for the evaluation. Symmetry was evaluated by comparing measurements between right and left sides for both groups and matching the middle points with the midsagittal axis. Statistical paired and simple t-test were used to evaluate the difference between the two sides for both groups. The measurements showed no significant skeletal and dental asymmetries except for three …

Single Molecule Emission Characteristics In Near-Field Microscopy, Randy X. Bian, Robert C. Dunn, X. Sunney Xie, P.T. Leung

Physics Faculty Publications and Presentations

In near-field scanning optical microscopy (NSOM), the measured fluorescence lifetime of a single dye molecule can be shortened or lengthened, sensitively dependent on the relative position between the molecule and aluminum coated fiber tip. The modified lifetimes and other emission characteristics are simulated by solving Maxwell equations with the finite-difference time-domain (FDTD) method. The 2D computation reveals insight into the lifetime behaviors and provides guidance for nonperturbative spectroscopic measurements with NSOM. This new methodology is capable of predicting molecular emission properties in front of a metal/dielectric interface of arbitrary geometry.

Design And Analysis Of Parallel Hierarchical Battlefield Simulation, Conrad P. Masshardt

Theses and Dissertations

The purpose of this research is to determine if hierarchically partitioning a discrete event battlefield simulation reduces runtime and, if reduction exists, to characterize the run time reduction given any particular partition configuration. A hierarchical discrete event simulation of a main battle tank was constructed. Implementations were built for both a single processor and a multiprocessing machine. The implementations used the Message Passing Interface to increase portability to other parallel and distributed configurations. Three test cases were generated and run on three parallel and distributed environments, a network of Sun SparcStation 20's, a Silicon Graphics Power Challenge, and a Paragon …

Mafic Volcanism In The Colorado Plateau: Basin And Range Transition Zone, Hurricane, Utah, Alexander Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Hurricane volcanic field (HVF) is a small-volume (0.48 km³) mafic volcanic field in the Colorado Plateau/Basin & Range Transition Zone located in the eastern part of the St. George basin in southwestern Utah. Strombolian-Hawaiian style eruptions produced thin (10 m) a'a lava flows and cinder (scoria) cones composed of vesicular basalt, bombs and agglutinate. Radiometric dating and geologic relationships demonstrate that the HVF formed over a period of at least 100,000 years. In the upper crust, magma probably rose along joints in sedimentary rocks because chains of volcanic vents follow joint orientation maxima in sedimentary rocks.

Three …

A Comparison Of Loose And Tight Gps/Ins Integration Using Real Ins And Gps Data, Warren H. Nuibe

Theses and Dissertations

An extended Kalman filter (EKE) is used to combine the information obtained from a Global Positioning System (GPS) receiver and an Inertial Navigation System (INS) to provide a navigation solution. This research compares the results of a tightly-coupled GPS/INS integrated system with a loosely-coupled integrated system, using real world data. A fair comparison is accomplished by using the same sets of data, and keeping the integration structures as close as possible. Both integrations are feedforward and have the same error states in the navigation Kalman filters. Differences between the two, such as navigation solutions and tuning values, are shown in …

The Separation Of Aqueous Iron Species Found In Stepwise Complexation By Capillary Electrophoresis With Atomic Absorption Spectroscopy Detection, Robert E. Sutton

Dissertations

A capillary zone electrophoresis system was interfaced to an atomic absorption spectrom eter to permit the separation and detection o f various species of iron found in step wise complexation in aqueous solutions. The samples were introduced at the anodic end of the column employing the electroosmotic flow to drive all the species to the detector at the cathodic end. Aqueous solutions of iron(II) and iron (III) chloride salts were among the compounds studied. The buffer employed w as a 20 millimolar (2-[N-morpholino]ethanesulfonic acid adjusted to a pH of 6 with 6 .6 millimolar potassium hydroxide. The detection limit was …

Recombination In Kr^34+ + H2 And 0^6+ + He Collisions, Konstantinos Zaharakis

Dissertations

No abstract provided.

Probabilistic Knowledge Base Validation, Howard T. Gleason

Theses and Dissertations

Our work develops a new methodology and tool for the validation of probabilistic knowledge bases throughout their lifecycle. The methodology minimizes user interaction by automatically modifying incorrect knowledge; only the occurrence of incomplete knowledge involves interaction. These gains are realized by combining and modifying techniques borrowed from rule-based and artificial neural network validation strategies. The presented methodology is demonstrated through BVAL, which is designed for a new knowledge representation, the Bayesian Knowledge Base. This knowledge representation accommodates incomplete knowledge while remaining firmly grounded in probability theory.

The Relationship Between Environmental Attitudes And Environmental Behaviors Among Air Force Members, Daniel T. Holt

Theses and Dissertations

A questionnaire was distributed to nearly 2,000 randomly selected active duty Air Force members assigned to locations throughout the continental United States. The survey was designed to determine the extent to which Air Force members expressed support for environmental issues. In addition, the survey measured how frequently Air Force members engaged in specific behaviors that were deemed environmentally protective. Although the Air Force members expressed relatively strong support for environmental issues, they only occasionally engaged in activities that contribute to the preservation or protection of the environment. Correlation analysis revealed that the pro-environmental attitudes were positively linked to the environmentally …

Dynamics Of Binary Liquids In Pores, J.C. Lee

Faculty Publications

A computer simulation is performed to study the dynamics of binary liquids in the pores of Vycor glasses. The pores are modeled with glass walls that form randomly interconnected tunnels. When the relaxation is probed with a particular wavelength, the time autocorrelation function depends on whether or not there is a significant periodic or quasiperiodic structure in the distribution of the walls with that wavelength. If there is not, the relaxation may be fitted as the sum of an exponential term and a nonexponential activated term. If there is, the relaxation shows a long-lasting tail that can be fitted by …

A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare

Masters Theses

Over a two year period, Western Michigan University ran a number of pump tests in the Asylum Lake Area in Kalamazoo, Michigan. The transmissivities and storativities calculated from these tests differed significantly from well to well in any particular test, and from pump test to pump test. Utilizing the computer programs AQTESOLV 3.0 and Aquifer Parameter Estimator, a number of T and S values were calculated. After analysis of the results, the following conclusion was drawn. The main reason for the deviations in the T and S values arose from the mixing of the results of numerous methods (some of …

Band Structure For Acoustic Waves Propagating In A Periodic Elastic Media And Impurity Modes Arising From Slab Substitutions, Abdur Rahman

Masters Theses

In this thesis I study the band structure for acoustic waves propagating in a one-dimensional elastic array which forms a periodic elastic system in which band gaps are opened in the frequency spectrum. Specifically, I study the single impurity problem in this system. An impurity is introduced in the system by replacing one of the acoustic slabs with a new slab of different acoustic medium or by changing the thickness of impurity slab. I study the very narrow (in frequency) impurity modes in the band gaps which are localized about the impurity sites. Then I study the frequency of impurity …

Regulation Of The Expression Of Lipogenic Enzymes By Insulin-Mimetics, Juiyu Wu

Masters Theses

Many researchers have shown that selenate (SeO₄^2-) and vanadate (VO₄^2-) have insulin-mimetic effects in certain biological processes. These mimetic effects include increasing glucose transport, regulating glycolytic enzymes, normalizing plasma glucose levels and activities of insulin regulated enzymes in diabetic rats. To clarify the functions and roles of these insulin-mimetics in different insulin-regulated metabolic pathways, the expression of the genes for glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS) were investigated. G6PDH is a key enzyme in the pentose phosphate pathway and is also involved in lipogenic metabolism by providing 55-70% of the NADPH utilization …

Distribution Of Submerged Aquatic Vegetation In The Chesapeake Bay And Tributaries And Chincoteague Bay - 1994, R J. Orth, Judith F. Nowak, Gary F. Anderson, David J. Wilcox, Jennifer R. Whiting, Leah S. Nagy

Reports

No abstract provided.

Water!, Kirk J. Havens, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

The Variability Of Carbon Dioxide In The Vadose Zone, John J. Ring

Masters Theses

The purpose of this thesis was to observe and attempt to explain the variations of carbon dioxide in the vadose zone of a nature area in southwestern Michigan. Well nests, consisting of discrete soil gas sampling points and temperature probes set at depths ranging from 3 to 53 feet, were constructed in a sandy, glacial outwash plain. Soil samples were collected for analysis of organic carbon content during installation. Soil gas samples were collected periodically from June, 1992 to March, 1993 and analyzed for CO₂ and O₂ concentrations. Occasionally, samples were collected and analyzed for isotopic C^{13 …}

The Effects Of Air Sparging On Aquifer Hydraulic Conductivity, Hans Neve

Masters Theses

Air sparging is a relatively new technology used to remove organic contaminants from aquifers. This remediation technique involves injecting into contaminated portions of water table aquifers. Theoretically air sparging will reduce aquifer hydraulic conductivity. Injected air fills some of the available sediment pores, thus restricting the flow of water to the remaining water-filled pore spaces.

The purpose of this study was to measure the reduction in hydraulic conductivity due to air sparging. This was assessed using both laboratory and field techniques. The hydraulic conductivities of several different sediments were determined in the laboratory using a large constant head permeameter modified …

Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu

Computer Science Faculty Publications and Presentations

This paper describes problems and solutions for delivering real-time, multi-media presentations across the Internet. A key characteristic of presentations of continuous media datatypes, such as digital video and audio, is their need for predictable real-time data delivery. For example, an NTSC quality video presentation requires video frames to be displayed every 1/30th of a second. Variations in this display rate can be observable as stalls or glitches in the video stream and reduce the quality of the presentation [6]. Delivering such presentations across the Internet is difficult because highly variable band- width and latency make it difficult to predict the …

Objectism 3.0: A Software Architecture For The Development Of Portable Visual Simulation Applications, Shawn M. Hannan

Theses and Dissertations

A visual simulation software architecture is a reusable design for visual simulation applications. This thesis effort was the third stage in an ongoing refinement of such an architecture, named ObjectSim. The primary goals of this stage were to improve the architecture by eliminating its dependence on two platform-specific graphics libraries (named GL and Performer, from Silicon Graphics, Inc.), and to examine the potential for expanding the architecture to accommodate distributed simulations. The effort resulted in a new version of the architecture which allows the development of visual simulation applications which take full advantage of the aforementioned libraries without calling those …

Model Of Chlorocarbon (Cfc-12) Chemisorption On Solid Rocket Motor Alumina Exhaust Particles, Gary E. Lund

Theses and Dissertations

Solid Rocket (SRMs) that power Titan IV rockets and Space Shuttles, exhaust large quantities of potentially ozone damaging pollutants directly into the stratosphere, while in powered flight. In the past, studies on potential stratospheric impact of the exhaust products from aluminum/ammonium perchlorate based SRMs have focused on the effect of gaseous HCl from SRMs on the stratosphere. Until recently, the impact of heterogeneous chemistry on stratospheric ozone was believed to be relatively insignificant. This research investigates the potential heterogeneous process of CFC-12 dissociative chemisorption on alumina surfaces and the release of reactive halogen species known to destroy ozone. Through a …

A Comparison Of Remediation Priorities Developed By The Defense Priority Model, The Relative Risk Evaluation Method, And A Quantitative Risk Assessment Approach, David M. Hunter

Theses and Dissertations

The Superfund, established by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, seriously underestimated both the number of severely contaminated sites and the associated cleanup cost. The magnitude of projected cleanup costs, coupled with shrinking federal budgets, necessitated the development and use of risk-based prioritization models among some federal agencies. Among these tools, the DOD prioritization models are meant to give priority to sites posing the greatest threat to human health. Their failure to properly rank sites could incorrectly shift the focus from those that pose substantial risk to sites of lesser risk. The DOD site ranking …