Physical Sciences and Mathematics Commons^™

Tunable Conductivity And Conduction Mechanism In An Ultraviolet Light Activated Electronic Conductor, Mariana I. Bertoni, Thomas O. Mason, Julia E. Medvedeva, Arthur J. Freeman, Kenneth R. Poeppelmeier, B. Delley

Physics Faculty Research & Creative Works

A tunable conductivity has been achieved by controllable substitution of an ultraviolet light activated electronic conductor. The transparent conducting oxide system H-doped Ca12-xMgxAl14O33 (x=0,0.1,0.3,0.5,0.8,1.0) presents a conductivity that is strongly dependent on the substitution level and temperature. Four-point dc-conductivity decreases with x from 0.26 S/cm (x=0) to 0.106 S/cm (x=1) at room temperature. At each composition the conductivity increases (reversibly with temperature) until a decomposition temperature is reached; above this value, the conductivity drops dramatically due to hydrogen recombination and loss. The observed conductivity behavior is consistent with the predictions of our first principles density functional calculations for the Mg-substituted …

Deep Roots: The Late Nineteenth Century Origins Of American Forestry, Char Miller

Pomona Faculty Publications and Research

The U.S. Forest Service celebrated its centennial in 2005, an event that depended on a set of individuals who in the years immediately prior to the agency’s creation in 1905 labored quietly, and sometimes not so quietly, to defuse opposition to the idea of it within the executive and legislative branches. Surely the most crucial of these figures was Gifford Pinchot, then head of the Bureau of Forestry, and President Theodore Roosevelt: animating their activism was a shared conviction that conservation of the nation’s natural resources would save the United States from economic ruin and a collective faith that a …

The Reflection Of Karst In The Online Mirror: A Survey Within Scientific Databases, 1960-2005, Lee J. Florea, Beth Fratesi, Todd A. Chavez

Academic Resources Faculty and Staff Publications

The field of cave and karst science is served by a literature that is dispersed across far-flung topical journals, government publications, and club newsletters. As part of an inter-institutional project to globalize karst information (KIP, the Karst Information Portal), the USF Library undertook a structured battery of literature searches to map the domain of karst literature. The study used 4,300 individual searches and four literature databases: GeoRef, BIOSIS, Anthropology Plus, and GPO Access. The searches were based on a list of 632 terms including 321 karst-related keywords culled from three leading encyclopedias and glossaries of cave and karst science. An …

Step-Pool Morphology Of A Wilderness Headwater Stream Of The Buffalo River, Arkansas, Aaron M. Nickolotsky

MSU Graduate Theses

Step-pool and cascade morphology reflect the geological and climatic factors affecting channels in mountain watersheds. This study uses longitudinal and cross-section surveys of a headwater stream in the Boston Mountains of the Ozarks Plateau region in northwest Arkansas to describe channel form and develop quantitative models for comparisons with other regions. The Bowers Hollow Creek watershed (3.5 km2) is located within the boundaries of the Forest Service’s Upper Buffalo Wilderness Area. Step-pool morphology varies with the influence of lithology and sediment supply in the Boston Mountains. However, step height and wavelength relationships are generally similar to other regions. Distribution of …

Nonaqueous Platination For Synthesis Of Platinated 7 Alpha-Substituted Estradiol, Sarah A. Mazzella

Masters Theses

No abstract provided.

The Application Of 31p And 1h Nmr Spectroscopy To The Study Of Freeze Tolerance And Freeze Avoidance In Biological Systems, Nicholas C. Wright

Masters Theses

No abstract provided.

Gmpac - The Generic Message Processing And Communications Framework, Eoin Barry

Theses

The Generic Message Processing and Communications Framework (GMPAC), is an extensible, communications architecture, which is concerned processing various message types. The GMPAC framework is designed around the java NIO API. It receives in various messages over a socket, decomposes them and extracts the payload. It then passes a message back to the sender in the same format as the received message. GMPAC uses xml files to define message formats, and decodes and decodes the messages using information contained in these definitions. This project was developed for Altobridge Tralee, meeting a set of requirements set out by them. This report provides …

Where Does It All End? Boundaries Beyond Euclidean Space, Jonathan Thompson

Inquiry: The University of Arkansas Undergraduate Research Journal

No abstract provided.

Semileptonic Decays Of D Mesons In Three-Flavor Lattice Qcd, James E. Hetrick, C. Aubin

All Faculty Articles - School of Engineering and Computer Science

We present the first three-flavor lattice QCD calculations for D-->pilnu and D-->Klnu semileptonic decays. Simulations are carried out using ensembles of unquenched gauge fields generated by the MILC Collaboration. With an improved staggered action for light quarks, we are able to simulate at light quark masses down to 1/8 of the strange mass. Consequently, the systematic error from the chiral extrapolation is much smaller than in previous calculations with Wilson-type light quarks. Our results for the form factors at q(2)=0 are f(D-->pi)(+)(0)=0.64(3)(6) and f(D-->K)(+)(0)=0.73(3)(7), where the first error is statistical and the second is systematic, added …

Planar Oxides As A Novel Approach To Metal Ion Sorption Studies: From The Lab To The Field, Christine F. Conrad

Dissertations, Theses, and Masters Projects

The purpose of this work is to investigate the use of planar oxides as tools for metal ion sorption studies that can be used in both laboratory and field settings. to do this, a three-step approach was used. In the first step, the reactivities of the planar gamma-Al2O3 surfaces relative to pure phase gamma alumina was investigated through Pb(II) sorption studies. The relative quantitative uptake of Pb(II) on the planar gamma alumina was found to be comparable to that on the bulk. XAS analysis showed that the coordination geometry and local binding environment of the Pb(II) complexes were similar on …

Tidal Wetland Contributions To Fecal Coliform Loads In Shellfish Growing Waters By Analysis Of Model Prediction Discrepancy, Jie. Huang

Dissertations, Theses, and Masters Projects

Fecal contamination in estuaries has become an increasing concern worldwide. The use of wetlands for wastewater treatment has expanded due to their natural ability to improve water quality by removing suspended sediments, nutrients, and fecal bacteria. In general, most of the removal occurs through deposition and accumulation in the wetland substrate. This would suggest that wetlands are effective filters for fecal coliform transported from terrestrial environments to surface waters. It has also been hypothesized, however, that wetlands may be an intermittent source of fecal coliform in tidal systems as a result of wildlife deposition and /or accumulation from terrestrial sources. …

Influence Of Environmental Factors On The Seed Ecology Of Vallisneria Americana, Jessie J. Campbell

Dissertations, Theses, and Masters Projects

Environmental conditions may positively or negatively influence production, reproduction, and restoration of submerged aquatic vegetation (SAV). As SAV populations decline, it is important to understand the potential impacts of the environment on the natural processes of reproduction. The objectives of this study are to provide fundamental information on sexual reproduction in a dominant species of freshwater SAV, Vallisneria americana, in the Chesapeake Bay observe the changes in environmental conditions in an established V. americana bed over an entire growing season (April-October), quantify the effects of similar environmental conditions on V. americana seed germination under controlled laboratory conditions, and finally to …

An Investigation Of Programmer-Identified Concerns, Meghan Kathleen Revelle

Dissertations, Theses, and Masters Projects

No abstract provided.

Cd-111 And Cd-113 Spin-Lattice Relaxation In Cdmoo4 By Paramagnetic Centers In The Absence Of Spin Diffusion, Peter A. Beckmann, Shi Bai, Cecil Dybowski

Physics Faculty Research and Scholarship

In an ongoing effort to understand the solid-state spin-lattice relaxation mechanism and its modulation for heavy-nuclei spin-1/2 systems like Pb-207 and Tl-203/Tl-205, we have serendipitously observed that the recovery of a saturated Cd-111 (or Cd-113) nuclear magnetization in CdMoO4 shows the three distinct time regions elucidated by Bodart [Phys. Rev. B 54, 15291 (1996)] when nuclear-spin relaxation is dominated by paramagnetic impurity relaxation in the complete absence of nuclear-spin diffusion.

Origin Of Pinning Enhancement In A Ferromagnet-Superconductor Bilayer, Marta Z. Cieplak, Xuemei Cheng, C. L. Chien, Hai Sang

Physics Faculty Research and Scholarship

Vortex pinning has been studied for the superconducting Nb film covering ferromagnetic Co/Pt multilayer with perpendicular magnetic anisotropy, in which the magnetization reversal proceeds via domain-wall motion. Large enhancement of pinning in the Nb film has been observed in the final stages of the reversal process, and we demonstrate that it is caused by residual uninverted dendrite-shaped magnetic domains.

Antisymmetric Magnetoresistance In Magnetic Multilayers With Perpendicular Anisotropy, Xuemei Cheng, S. Urazhdin, O. Tchernyshyov, C. L. Chien, V. I. Nikitenko, A. J. Shapiro, R. D. Shull

Physics Faculty Research and Scholarship

While magnetoresistance (MR) has generally been found to be symmetric in applied field in nonmagnetic or magnetic metals, we have observed antisymmetric MR in Co/Pt multilayers. Simultaneous domain imaging and transport measurements show that antisymmetric MR is due to the appearance of domain walls that run perpendicular to both the magnetization and the current, a geometry existing only in materials with perpendicular magnetic anisotropy. As a result, the extraordinary Hall effect gives rise to circulating currents in the vicinity of domain walls that contributes to the MR. The antisymmetric MR and extraordinary Hall effect have been quantitatively accounted for by …

Establishing An Online Community Of Practice For Instructors Of English As A Foreign Language, Christopher M. Johnson

CCE Theses and Dissertations

Communities of practice are entities that emerge for the purposes of learning and advancement of knowledge in a particular area. They emerge under all circumstances, even adverse situations. Because they can spawn great innovation and knowledge advancement, organizations need to cultivate and establish environments that allow them to develop. Currently, communities of practice have moved into the online world, in which their members use computer mediated communication to collaborate with each other.

In January, 2002, a virtual community was formed to enable teachers of English as a Foreign Language to collaborate on learning and applying various computing technologies in language …

A Self-Adaptive Evolutionary Negative Selection Approach For Anomaly Detection, Luis J. Gonzalez

CCE Theses and Dissertations

Forrest et al. (1994; 1997) proposed a negative selection algorithm, also termed the exhaustive detector generating algorithm, for various anomaly detection problems. The negative selection algorithm was inspired by the thymic negative selection process that is intrinsic to natural immune systems, consisting of screening and deleting self-reactive T-cells, i.e., those T-cells that recognize self-cells.

The negative selection algorithm takes considerable time (exponential to the size of the self-data) and produces redundant detectors. This time/size limitation motivated the development of different approaches to generate the set of candidate detectors.

A reasonable way to find suitable parameter settings is to let an …

The Effects Of Computerized Smell Of Memory, Brandon Spencer

CCE Theses and Dissertations

It has long been recognized that there is a major correlation between smell and memory. Until recently, commercialized multi-sensory experiences involving olfaction were limited to non-computerized mediums. Companies that manufacture computerized scent technologies tout the educational benefits of their product, yet prior to this study, there appeared to be no scholarly research in regard to the efficacy of computerized scent producing peripherals in educational environments. The aim of this research was to determine the odor memory enhancement benefits of incorporating olfactory, computerized peripherals into computerized multimedia-learning environments, from both a context dependent and context independent stand point. Specifically, within a …

Strategy For The Implementation Of An Industrial Land Bank, Kevin O'Brien, Kirstin S. Toth, Matthew Sattler, Michael Mcgoun, Jacob Duritsky

All Maxine Goodman Levin School of Urban Affairs Publications

The City of Cleveland plans to create a long-term vision for industrial and commercial land reuse in order to better serve the business and neighborhood interests of its citizens. The implementation of an industrial land bank is one critical way in which to fulfill this goal. This study aimed to develop a strategy to aid the city in the operation and management of rehabilitating commercial and industrial properties for reuse. The objectives of the project were to: * Incorporate a strategy understood by senior managers at the city that identifies a broad economic redevelopment vision, especially for brownfields. * Include …

Incompressible Finite Elements Via Hybridization. Part I: The Stokes System In Two Space Dimensions, Bernardo Cockburn, Jay Gopalakrishnan

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we introduce a new and efficient way to compute exactly divergence-free velocity approximations for the Stokes equations in two space dimensions. We begin by considering a mixed method that provides an exactly divergence-free approximation of the velocity and a continuous approximation of the vorticity. We then rewrite this method solely in terms of the tangential fluid velocity and the pressure on mesh edges by means of a new hybridization technique. This novel formulation bypasses the difficult task of constructing an exactly divergence-free basis for velocity approximations. Moreover, the discrete system resulting from our method has fewer degrees …

Asymptotic Methods In The Spectral Analysis Of Sturm-Liouville Operators, Daphne Gilbert

Articles

Gilbert, D.: Asymptotic Methods in the Spectral Analysis of Sturm-Lioville Operators.Sturm-Liouville theory : Past and Present, 2005, pp 121-136.

An Elementary Method For Calculating Orientation-Averaged Fully Differential Electron-Impact Ionization Cross Sections For Molecules, Junfang Gao, Jerry Peacher, Don H. Madison

Physics Faculty Research & Creative Works

Currently there are no reliable theoretical approaches for calculating fully differential cross sections (FDCS) for low-energy electron-impact ionization of large molecules. We have recently introduced the distorted-wave impulse approximation as a first step in developing improved theoretical approaches. One significant obstacle to evaluating improved theoretical approaches which require significant computer resources lies in the fact that the existing experimental data require taking averages over all molecular orientations. To circumvent this problem, it has been proposed to approximate the orientation-average by using an orientation-averaged molecular orbital in the calculation of the FDCS. The theoretical justification and expected range of validity for …

Fully Differential Cross Sections For Low-Energy Electron-Impact Ionization Of Nitrogen Molecules, Junfang Gao, Don H. Madison, Jerry Peacher

Physics Faculty Research & Creative Works

Currently there is no accurate theoretical approach available for treating fully differential cross sections (FDCS) for low-energy electron-impact ionization of large molecules. For high incident energies, the plane wave impulse approximation (PWIA) generally yields good agreement with experimental data. In this paper, the distorted wave impulse approximation (DWIA) is used to calculate FDCS for low-energy electron-impact ionization of N2. To perform the necessary average over all molecular orientations, we propose an orientation average (OA) approximation. Although the DWIA results represent an improvement over the PWIA for intermediate energies, an improved theory is necessary for lower energies. However, the OA approximation …

Role Of Embedded Clustering In Dilute Magnetic Semiconductors: Cr Doped Gan, Julia E. Medvedeva, B. Delley, N. Newman, C. Stampfl, X. Y. Cui, Arthur J. Freeman

Physics Faculty Research & Creative Works

Results of extensive density-functional studies provide direct evidence that Cr atoms in Cr:GaN have a strong tendency to form embedded clusters, occupying Ga sites. Significantly, for larger than 2-Cr-atom clusters, states containing antiferromagnetic coupling with net spin in the range 0.06-1.47 µB/Cr are favored. We propose a picture where various configurations coexist and the statistical distribution and associated magnetism will depend sensitively on the growth details. Such a view may elucidate many puzzling observations related to the structural and magnetic properties of III-N and other dilute semiconductors.

Measurement Of Lipid Peroxidation In Biology Models Using Gas-Chromatography-Aass Spectrometry, Madhavi Lokireddy

Master's Theses and Doctoral Dissertations

C2C12 mouse myoblast cells, grown in glass vials, were connected to a cryofocusing unit to trap volatile organic compounds (VOCs). The VOCs were eluted from the trap by capacitive discharge into a gas chromatograph with time-of-flight mass spectral capabilities (GC-TOFMS) and were found to include the lipid peroxidation product hexanal. The pro-oxidant cumene hydroperoxide elevated the levels of these lipid peroxidation products, whereas the anti-oxidant butylated hydroxy toluene (BHT) impaired their production. Derivatization of the aldehyde products of lipid peroxidation in the same myoblast cells with pentafluorobenzyl hydroxylamine hydrochloride (PFB) provided evidence for formation of non-volatile products of lipid peroxidation …

Investigation Of The Optical, Thermal, And Mechanical Properties Of A Bulk Polymer Using The Surface Thermal Lensing Technique, Bushra Hussain

Master's Theses and Doctoral Dissertations

The sensitive and simple photothermal technique of Surface Thermal Lensing (STL) was employed to study the thermo-mechanical response of an amorphous polycarbonate as a bulk. A discussion is given of how previously developed theories did not fit well with the present work. Therefore, only qualitative analysis and discussion of the experimental results is made, emphasizing the influence of various factors on the STL signal. The work here is mainly a study of the dependence of the STL signal on the modulated pump beam frequency. The effect on the STL signal of thermal and mechanical relaxation in the thermally stimulated area …

Characterization Of Black Deposit Associated With Rock Paintings In Little Lost River Cave, Idaho Using Pyrolysis Gc, Sarah Therese Fezzey

Master's Theses and Doctoral Dissertations

A black, shiny coating overlies rock paintings in Little Lost River Cave no. 1, located in southeastern Idaho. If this coating is the result of human activity within the cave – a condensate from cooking fires, for example – then a radiocarbon date on the coating would provide a minimum age for the underlying paintings. The work reported here was undertaken to test the assumption that the coating has an anthropomorphic origin. Using pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) and thermally-assisted hydrolysis/methylation-GC-MS, we have compared samples of the black coating from Idaho to humic acid, a geologic material; an experimental cooking residue; …

An Investigation Into The Ring-Enlargement Reactions Of Boron Subphthalocyanine And Boron Subnaphthalocyanine, Andrew Jeremiah Jones

Master's Theses and Doctoral Dissertations

Ring enlargement syntheses of axially substituted boron subphthalocyanine and boron subnaphthalocyanine were investigated. The trihexylsiloxy derivatives of subphthalocyanine and subnaphthalocyanine were synthesized. These derivatives were then used in the ring-enlargement trials. Symmetrical and asymmetrical ring-enlargement reactions were carried out in a mixture of toluene and dimethylsulfoxide at room temperature. This study represents the first synthesis of boron subphthalocyanine with trihexylsiloxy group in the axial position and the first investigation into the ring enlargement of boron subnaphthalocyanine in which the axial ligand is a trihexylsiloxy group. Precipitates were formed, and it is believed that the precipitates are the metalfree ring-enlarged products. …

Winter Bird Use Of The Chinese Tallow Tree In Louisiana, Michael John Baldwin

LSU Master's Theses

Chinese tallow (Triadica sebifera) is a non-native invasive tree that is of particular concern in the Southeastern United States. It has become naturalized in a variety of habitats and can be found in monospecific stands. The use of tallow woodlands by overwintering birds is poorly documented. I compared use of tallow woodlands to use of bottomland hardwood forests by birds in the Mermentau River Basin, Louisiana. Species richness and evenness were greater in the bottomland hardwood sites. Three species were more abundant in tallow woodlands, six species were more common in bottomland hardwoods, and six species exhibited no difference between …