Physical Sciences and Mathematics Commons^™

Pride Water Quality Assessment Report: Ii. Chemical, Biological And Habitat Assessments, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Research Reports

The efficient utilization of federal funds in improving the water quality and aquatic habitat of the region requires a mechanism for assessing and evaluating the impacts of the proposed and ongoing projects as well as some mechanism for prioritizing the allocation of additional funds. In order to evaluate the effectiveness of these projects it is important to provide a formal monitoring and assessment program based on sound scientific principles. This report provides an initial 10 year baseline assessment of the existing water quality conditions in the 40 county PRIDE·region for the purpose of evaluating the impacts of the PRIDE programs …

Beneficial Use Of Dredge Material For Tampa Bay Bottom Habitat Restoration, Tampa Baywatch, Inc.

Reports

A brief description of each site is included in the text, with contact information where available. The 11 sites were selected due to their location, potential for restoration, active projects under development, public safety issues and proximity to a source of fill material. Again, the survey is intended to be a starting point. All sites will require an extensive evaluation, including opportunities for public input, before restoration plans can move forward.

Arthur County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 3, Robert F. Diffendal Jr., James W. Goeke

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test holes drilled in Arthur County under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies.

The maps in this report show the locations of all test holes drilled in the county since 1934.

Present techniques …

Utah State University Ground-Based Test Facility For Study Of Electronic Properties Of Spacecraft Materials, W. Y. Chang, John R. Dennison, Neal Nickles, R. E. Davies

All Physics Faculty Publications

Materials used for spacecraft and space structures in near-Earth orbit are subject to severe environmental effects including high vacuum conditions, hot and cold extremes temperature, strongly oxidizing atomic oxygen environments, and high fluxes of energetic electrons, ions, neutrals and photons. Instrumentation developed at Utah State University is designed to simulate, at least to some level, all of these conditions and to study charged particle and photon interactions with spacecraft surfaces. The facilities are particularly well suited to study electron emission as related to spacecraft charging, including secondary and backscattered yields, energy-spectra, and angleresolved measurements as a function of incident energy, …

Evolution Of Secondary Electron Emission Characteristics Of Spacecraft Surfaces: Importance To Spacecraft Charging, Robert Davies, John R. Dennison

All Physics Faculty Publications

A sample of oxidized aluminum was placed inside an ultra-high vacuum (UHV) chamber alongside a piece of PTFE (Teflon®) coated wire and continuously bombarded with 1-3 keV electrons for ~30 hours. The SE yield of the surface was monitored as a function of time throughout the electron bombardment. Oxidized aluminum was chosen as a typical material comprising spacecraft surfaces, while outgassing of the Teflon wire contaminated the UHV environment, simulating the microenvironment surrounding an operating spacecraft. Continuous electron bombardment resulted in two effects—( i) the removal of the oxide layer, and (ii) the deposition of a thin (~1 nm-thick) layer …

Applications Of Secondary Electron Energy- And Angular-Distributions To Spacecraft Charging, Neal Nickles, R. E. Davies, John R. Dennison

All Physics Faculty Publications

Secondary electron (SE) emission from spacecraft surfaces as a result of energetic electron bombardment is a key process in the electrical charging of spacecraft. It has been suggested that incorporating more complete knowledge of the energy- and angular-distributions of secondary electrons is necessary to fully model how SE emission and spacecraft charging are affected by re-adsorption of low energy electrons in the presence of charge-induced electrostatic fields and ambient magnetic fields in the spacecraft environment. We present data for such energy- and angular-distributions from sputtered, polycrystalline gold surfaces. The data are compared to empirical SE emission models and found to …

Spatial And Temporal Changes In Land Use And Land Cover From 1988 To 1992 In The Upper White River Watershed, H. D. Scott, J. M. Mckimmey

Technical Reports

Changes in Land Use and Land Cover (LULC) in the upper White River Watershed from 1988 to 1992 were analyzed and plotted using the geographic information system known as Geographic Resources Analyses Support System (GRASS). This portion of the White River Watershed includes two sub-basins the East Fork and the Middle Fork. In addition, LULC changes were determined for two smaller sub-basins, Shumate Creek and Cannon Creek, located in the East Fork of the White River. The sources and methods of interpretation of the 1988 and 1992 of data were different. Thus, there were variations in how certain portions of …

Reply To "Comment On 'Mössbauer Effect Study Of Filled Antimonide Skutterudites'", Gary J. Long, Gary J. Long, Dimitri Hautot, Fernande Grandjean, Donald T. Morelli, Gregory P. Meisner

Chemistry Faculty Research & Creative Works

The temperature dependence of the isomer shift of α-iron between 4.2 and 990 K and of Dy₃Fe₅O₁₂ between 4.2 and 550 K has been analyzed in terms of the Debye model for the second-order Doppler shift, a model in which an additional parameter, the effective vibrating mass, is included. This mass is found equal to 57 g/mol in the ionic compound, Dy₃Fe₅O₁₂, and equal to 60 g/mol in metallic α-iron. The deviation of this mass from 57 g/mol is a measure of the covalency of the metallic bonding in …

Short-Pulse Laser-Induced Stabilization Of Autoionizing States, Heider N. Ereifej, J. Greg Story

Physics Faculty Research & Creative Works

Atoms in doubly excited states above the first ionization limit can decay via autoionization in which an electron is emitted leaving an ion, or by photoemission which leaves the atom in a singly excited state. In this paper, it is demonstrated that interaction between the atoms and a laser pulse that is short compared to the autoionization lifetime can lead to large enhancement of the photoemission process by stimulating the atoms to emit a photon. Since the resultant singly excited atoms do not autoionize, this process can be viewed as an enhancement of the stabilization of the doubly excited atoms …

Concept Of Local Polaritons And Optical Properties Of Mixed Polar Crystals, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky

Physics Faculty Research & Creative Works

The concept of local polaritons is used to describe the optical properties of mixed crystals in the frequency region of their restrahlen band. It is shown that this concept allows for a physically transparent explanation of the presence of weak features in the spectra of so-called one-mode crystals and for one-two mode behavior. The previous models Were able to explain these features only with the use of many fitting parameters. We show that under certain Conditions new impurity-induced polariton modes may arise within the restrahlen of the host crystals, and study their dispersion laws and density of states. Particularly, we …

A Science-Based Initiative To Manage Double-Crested Cormorant Damage To Southern Aquaculture, James F. Glahn, Mark E. Tobin, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

Aquaculture has expanded rapidly in the Southern United States during the past two decades, especially the cultivation of catfish, crawfish, and bait fish. These fish usually are cultivated on farms with extensive systems of large shallow ponds that are highly susceptible to predation by birds. Double-crested cormorants (Phalacrocorax auritus ), American white pelicans (Pelecanus erythrorhynchos ), wading birds (e.g., Ardea alba, Ardea herodius ), and scaup (Aythya spp. ) are among the birds most frequently implicated. Well-documented problems associated with cormorant predation on catfish farms have coincided with the increase of this industry and the rapid …

A Structural, Magnetic, And Mössbauer Spectral Study Of Dy2fe17 And Its Hydrides, O. Isnard, Dimitri Hautot, Gary J. Long, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The structural and magnetic properties of the [formula omitted] compounds, where x is 0, 1, 2, 3, and 3.8, have been investigated by means of powder x-ray diffraction, thermomagnetic and ac magnetic susceptibility measurements, and iron-57 Mössbauer spectroscopy. The Dy₂Fe₁₇H_x compounds crystallize in a hexagonal Th₂Ni₁₇ -like structure which has both an iron-rich stoichiometry and disorder of the Dy and Fe–Fe dumbbell sites. The increase in the lattice parameters, the magnetic ordering temperature, the saturation magnetization, and the dependence of the Mössbauer hyperfine parameters upon hydrogen content support a two-step filling by …

Distributed Development And Deployment Of Ontologies For Knowledge-Based Systems, Sameh El-Ansary

Archived Theses and Dissertations

No abstract provided.

Reversible Dissociation Of Thiolate Ligands From Molybdenum In An Enzyme Of The Dimethyl Sulfoxide Reductase Family, Robert C. Bray, Benjamin Adams, Andrew T. Smith, Brian Bennett, Susan Bailey

Physics Faculty Research and Publications

Much is unknown concerning the role of thiolate ligands of molybdenum in molybdopterin enzymes. It has been suggested that thiolate dissociation from molybdenum is part of the catalytic mechanism of bis-molybdopterin enzymes of the dimethyl sulfoxide reductase (DMSOR) family. For DMSOR from Rhodobacter capsulatus, thiolate dissociation has therefore been investigated crystallographically, by UV/visible spectroscopy, and by enzyme assays. When crystallized from sodium citrate, all four thiolates of DMSOR are within bonding distance of Mo, but after extended exposure to Na⁺-Hepes, a pair of thiolates dissociates, a mixture of structures being indicated after shorter exposures to this buffer. …

Validation And Verification Of Formal Specifications In Object-Oriented Software Engineering, Steven A. Thomson

Theses and Dissertations

The use of formal specifications allows for a software system to be defined with stringent mathematical semantics and syntax via such tools as propositional calculus and set theory. There are many perceived benefits garnered from formal specifications, such as a thorough and in-depth understanding of the domain and system being specified and a reduction in user requirement ambiguity. Probably the greatest benefit of formal specifications, and that which is least capitalized upon, is that mathematical proof procedures can be used to test and prove internal consistency and syntactic correctness in an effort to ensure comprehensive validation and verification (V&V). The …

Algorithm Development For On-Line Control Of The Airborne Laser, Michael W. Oppenheimer

Theses and Dissertations

The use of adaptive optics entails the design of a controller. This requires the development of a model of the plant to be controlled, which, in this case, Consists of the atmosphere through which light is traveling. In optics, Zemike polynornials are used as a basis set for the expansion of wavefront phase distortions. Due to the turbulence induced stochastic nature of the underlying process involved, the spatial-temporal correlation functions of the Zemike polynomial phase expansion coefficients must be evaluated if a proper stochastic model of the plant is to be developed and adaptive optics is to be employed. In …

Illinois River 1999 Pollutant Loads At Arkansas Higway 59 Bridge, Marc A. Nelson, Thomas S. Soerens

Technical Reports

Automatic water samplers and aU. S. Geological Survey gauging station were established in 1995 on the main stem of the Illinois River at the Arkansas Highway 59 Bridge. Since that time, continuous stage and discharge measurements and water quality sampling have been used to determine pollutant concentrations and loads in the Arkansas portion of the Illinois River. This report represents the results from the measurement and sampling for January 1, 1999 to December 31, 1999.

Ground Water In Northwest Arkansas: Minimizing Nutrient Contamination From Non-Point Sources In Karst Terrane, R. K. Davis, J. V. Brahana, J. S. Johnston

Technical Reports

The purpose of the project is to evaluate the effectiveness of Best Management Practices (BPMs) in preventing non-point source contamination of the ground-water resources in the karst terrane of northwestern Arkansas. Limestone and dolomite aquifers in the region are highly vulnerable to contamination. Ground-water studies performed in the region during the last two decades indicate degradation of these carbonate aquifers by nutrients and bacteria. The expeditious growth of the poultry industry during this period, in combination with the inordinate population growth of the region constitute a threat to the ground-water resources from both point sources and non-point sources of contamination. …

Two-Photon Detachment Cross Sections And Dynamic Polarizability Of H- Using A Variationally Stable, Coupled-Channel Hyperspherical Approach, Mauro Masili, Anthony F. Starace

Anthony F. Starace Publications

We present a generalization of the variationally stable method of Gao and Starace [B. Gao and A. F. Starace, Phys. Rev. Lett. 61, 404 (1988); Phys. Rev. A 39, 4550 (1989)] for two-electron atoms and ions that incorporates a coupled-channel adiabatic hyperspherical approach. Using this approach, we report results for two-photon detachment of H^-, in which we have coupled one, two, three, and four adiabatic hyperspherical channels within each term level of the initial, intermediate, and final states. We present results also for the dynamic polarizability of H^- as well as for the one-photon detachment cross section. …

How Does Cross-Linking Effect The Thermal Stability Of Polyisoprene, Qiang Yao, Charles A. Wilkie

Chemistry Faculty Research and Publications

Polyisoprene can be cross-linked by an initial lithiation followed by reaction with both monochloro compounds and dichloro compounds. The monochloro compounds effect crosslinking through a lithium-chlorine exchange route while the use of dichloro compounds links the PIP chains with the spacer between the two chlorine atoms. A significant amount of char is produced from compounds which have been cross-linked with aromatic dihalides while aliphatic dihalides do not produce significant char.

Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang, Roland T. Chin

Research Collection School Of Computing and Information Systems

We present a new ly developed scheme for automatical ly partitioning videos into scenes. A scene is general ly referred to as a group of shots taken place in the same site. In this paper, we first propose a motion annotation algorithm based on the analysis of spatiotemporal image volumes. The algorithm characterizes the motions within shots by extracting and analyzing the motion trajectories encoded in the temporal slices of image volumes. A motion-based keyframe computing and selection strategy is thus proposed to compactly represent the content of shots. With these techniques, we further present a scene change detection algorithm …

Virginia's Public Beach Board 20 Years Of Coastal Management, Donna A. Milligan, C. Scott Hardaway Jr.

Reports

No abstract provided.

A New Autonomous Underwater Vehicle For Imaging Research, C. Roman, O. Pizarro, R. Eustice, H. Singh

Christopher N. Roman

Currently, unmanned underwater vehicles either tend to be cumbersome and complex to run, or operationally simple, but not quite suitable platforms for deep water imaging. This paper presents an alternative design in the form of a new low cost and easier to use autonomous underwater vehicle (AUV) for imaging research. The objective of the vehicle is to serve as a readily available and operationally simple tool that allows rapid testing of imaging algorithms in areas such as photomosaicking, 3D image reconstruction from a single camera, image based navigation, and multi-sensor fusion of bathymetry and optical data. These are all current …

An Autonomous Water Vapor Plume Tracking Robot Using Passive Resistive Polymer Sensors, S. Kazadi, R. Goodman, D. Tsikata, D. Green, H. Lin

Sanza Kazadi

A Support Vector Method For Clustering, Asa Ben-Hur, David Horn, Hava Siegelmann, Vladimir Vapnik

Hava Siegelmann

We present a novel method for clustering using the support vector machine approach. Data points are mapped to a high dimensional feature space, where support vectors are used to define a sphere enclosing them. The boundary of the sphere forms in data space a set of closed contours containing the data. Data points enclosed by each contour are defined as a cluster. As the width parameter of the Gaussian kernel is decreased, these contours fit the data more tightly and splitting of contours occurs. The algorithm works by separating clusters according to valleys in the underlying probability distribution, and thus …

Relaxation Dynamics Of Rubbed Polystyrene Thin Films, D. M. G. Agra, A. D. Schwab, J-H. Kim, Satyendra Kumar, A. Dhinojwala

Satyendra Kumar

Optical retardation measurements were used to probe the chain relaxation dynamics in rubbed polystyrene films of varying thicknesses on glass substrates. A model based on Kohlrausch-Williams-Watts relaxation was developed and used to determine the glass transition temperature (Tg) of the films. Results showed reductions of 15–20 K in Tg for thin films of thicknesses comparable to the radius of gyration as well as for cast films rubbed with different strengths. These results provide evidence of a faster relaxation dynamics relative to the polymer-substrate interface for thinner films and enhanced chain mobility at the polymer-air interface.

Measurements Of The Hyperpolarizability Tensor By Means Of Hyper-Rayleigh Scattering, Liang-Chy Chien, V. Ostroverkhova, R. G. Petschek, K. D. Singer, L. Sukhomlinova, R. J. Twieg, S.-X. Wang

Liang-Chy Chien

We describe improvements to a previously reported hyper-Rayleigh scattering technique [J. Opt. Sec. Am. B 15, 289 (1998)], for measuring all rotational invariants of the first hyperpolarizability tensor. The full hyper-Rayleigh scattering tensor is expressed in terms of its rotationally invariant components leading to a figures of merit corresponding to each of the rotationally invariant tensors. With elliptically polarized incident light, the polarization state and the intensity of the harmonic light are measured at a scattering angle of 45 degrees. A new analytical fitting method is applied to the signal for two polarization measurements to yield the invariants. We have …

Knowledge Discovery In Biological Databases : A Neural Network Approach, Qicheng Ma

Dissertations

Knowledge discovery, in databases, also known as data mining, is aimed to find significant information from a set of data. The knowledge to be mined from the dataset may refer to patterns, association rules, classification and clustering rules, and so forth. In this dissertation, we present a neural network approach to finding knowledge in biological databases. Specifically, we propose new methods to process biological sequences in two case studies: the classification of protein sequences and the prediction of E. Coli promoters in DNA sequences. Our proposed methods, based oil neural network architectures combine techniques ranging from Bayesian inference, coding theory, …

Deactivation And Enhancement Effects Of Sulfur On Supported Platinum Oxidation Catalysts, Mark Ladolcetta

Dissertations

The effects of sulfur poisoning on the oxidation activity of 1.5 % Pt/γ-Al₂O₃, Pt/TiO₂, Pt/ZrO₂, and Pt/SiO₂, were investigated in this study. Each catalyst was poisoned with an H₂S/air or SO₂/air mixture at 400°C for 24 hours and a sulfur concentration of 200 ppm. The complete oxidation of mixtures of I % CO, methane, ethane, ethene, ethyne, propane, propene, and n-butane in air were measured over fresh and sulfurpoisoned catalysts.

Non-methane alkane oxidation activity was enhanced significantly after sulfur poisoning on all four catalysts. The temperatures …

Normal Numbers Without Measure Theory, R. Nillsen

Faculty of Informatics - Papers (Archive)

Any number can be expanded to the base 10, leading to a sequence of digits between 0 and 9 corresponding to the number. Also, any number can be expanded to the base 2, leading to a sequence of digits, each one being either 0 or 1, corresponding to the number. It is result due to Émile Borel in 1904 that “almost all” numbers have the property that, when expanded to the base 2, each of the digits 0 and 1 appears with an asymptotic frequency of 1/2. That is, if we regard the sequence of digits in the expansion to …