Physical Sciences and Mathematics Commons^™

The Status Of Fishes In The Missouri River, Nebraska: Lake Sturgeon (Acipenser Fulvescens), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Lake Sturgeon (Acipenser fulvescens) occurrences in the Missouri River along Nebraska’s eastern border are historically sporadic and rare. Presently, the wild Lake Sturgeon population in this river reach may be extirpated. A Recovery Program initiated by the Missouri Department of Conservation (MDC) has stocked almost 150,000 hatchery-reared Lake Sturgeon into the lower Missouri River at several sites in Missouri. As a result, the number of Lake Sturgeon collected has increased. Since monitoring began in 2003, no Lake Sturgeon have been collected above Gavins Point Dam while 40 fish were collected downstream of Gavins Point Dam. The majority of …

Pre-Breakdown Arcing And Electrostatic Discharge In Dielectrics Under High Dc Electric Field Stress, Allen Andersen, Jr Dennison

Journal Articles

Highly disordered insulating materials exposed to high electric fields will, over time, degrade and fail, potentially causing catastrophic damage to devices. Step-up to electrostatic discharge (ESD) tests were performed for two common polymer dielectrics, low density polyethylene and polyimide. Pre-breakdown transient current spikes or arcs were observed, using both slow and high speed detection. These pre-ESD discharge phenomena are explained in terms of breakdown modes and defect generation on a microscopic scale. The field at which pre-breakdown arcing begins was compared to the onset field for electrostatic discharge at which complete breakdown occurs for each material studied. We present evidence …

Distribution Of Dissolved Trace Metals And Carbon System Parameters In The Surface Waters Of The Hillsborough River And Tampa Bay, Matthew Matthias Elliott

USF Tampa Graduate Theses and Dissertations

This work represents a first look at the general spatial distribution of trace metals and the inorganic carbon system in the surface waters of Tampa Bay. Tampa Bay's chemical environment bears many influences ranging from hydrological and geological to anthropogenic and meteorological. A large y-shaped estuary on the west-central side of the Florida Peninsula, Tampa Bay extends over 400 square miles and has a 2200 square mile watershed that includes extensive swamps, scrub, agricultural lands and densely urbanized areas. Reaching 37 miles from the northernmost point of Old Tampa Bay to the mouth of the estuary near the Sunshine Skyway …

The Figure Of Bitu-Man, Paul Royster

UNL Libraries: Faculty Publications

The ominously imposing figure in the above illustration is “the Syncrude bird deterrent device, locally known as ‘Bitu-man’.” He stands (or stood—the original image was from the late 1970s) in the tailings pond of the Syncrude Canada Ltd. oil sands mining operation along the Athabasca River near Fort McMurray in northeastern Alberta. That operation surface mines (i.e., strip mines) bitumen-impregnated sand, processes it with hot water and steam, and discharges the liquid effluent or “tailings” into a pond covering roughly 3000 hectares (11 square miles). (Google Map coordinates: 56.9°N, -111.3° W). Residue bitumen collects on the surface and poses a …

Cosm News, Georgia Southern University

College of Science and Mathematics News (2012-2019)

• Graduate Student Honored with Scholarship by the German Academic Exchange Service

Photophysical And Electronic Properties Of Low-Bandgap Semiconducting Polymers, Evan Lafalce

USF Tampa Graduate Theses and Dissertations

In this Ph.D. work, we investigate the optoelectronic properties of low-bandgap semiconducting polymers and project the potential for employing these materials in electronic and photonics devices, with a particular emphasis on use in organic solar cells. The field of organic solar cells is well developed and many of the fundamental aspects of device operation and material requirements have been established. However, there is still more work to be done in order for these devices to ultimately reach their full potential and achieve commercialization. Of immediate concern is the low power conversion efficiency demonstrated in these devices so far. In order …

Photochromic Molecular Materials For The Controlled Organization Of Nanoparticles, Kristen Elise Snell

Electronic Thesis and Dissertation Repository

The displacement of polystyrene nanoparticles promoted by bulk azo mass transfer using interferential light illumination will be discussed. For this a variety of different push pull small azo molecules were synthesis and characterized, changing the polarity, hydrophobicity and bulky groups around the azo moiety. These small dyes appear to orientate quicker than similarly report azo polymers, of entanglement of the azobenzene group in the polymeric backbone. These dyes were used to form surface relief grating on the thin films due to the bulk mass transfer. This mass transfer was exploited to align polystyrene nanoparticles in the crests and troughs of …

U.S. Drought Monitor, October 21, 2014, Michael J. Brewer

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for October 21, 2014 (10/21/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Warming Reduces Tall Fescue Abundance But Stimulates Toxic Alkaloid Concentrations In Transition Zone Pastures Of The U.S., Rebecca L. Mcculley, Lowell P. Bush, Anna E. Carlisle, Huihua Ji, Jim A. Nelson

Plant and Soil Sciences Faculty Publications

Tall fescue pastures cover extensive acreage in the eastern half of the United States and contribute to important ecosystem services, including the provisioning of forage for grazing livestock. Yet little is known concerning how these pastures will respond to climate change. Tall fescue's ability to persist and provide forage under a warmer and wetter environment, as is predicted for much of this region as a result of climate change, will likely depend on a symbiotic relationship the plant can form with the fungal endophyte, Epichloë coenophiala. While this symbiosis can confer environmental stress tolerance to the plant, the endophyte …

Casimir Energies In Spherically Symmetric Background Potentials Revisited, Matthew Beauregard, Michael Bordag, Klaus Kirsten

Faculty Publications

In this paper we reconsider the formulation for the computation of the Casimir energy in spherically symmetric background potentials. Compared to the previous analysis, the technicalities are much easier to handle and final answers are surprisingly simple.

Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors, Jeffrey Yen, Benjamin Shank, Betty Young, Blas Cabrera, Paul Brink, Matthew Cherry, John Mark Kreikebaum, Robert Moffatt, Peter Redl, Astrid Tomada, Ted Tortorici

Faculty Publications

We report on experimental studies of phonon sensors which utilize quasiparticle diusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al lms in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al lms using a simple diusion equation approach. These studies allow the design of phonon sensors with improved performance.

The Bulge–Disc Decomposed Evolution Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Zoo, E. J. Mcgrath

Physics and Astronomy Faculty Publications

We present the results of a new and improved study of the morphological and spectral evolution of massive galaxies over the redshift range 1 < z < 3. Our analysis is based on a bulge–disc decomposition of 396 galaxies with M_* > 10¹¹ M_⊙ uncovered from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) Wide Field Camera 3 (WFC3)/IR imaging within the Cosmological Evolution Survey (COSMOS) and UKIRT Infrared Deep Sky Survey (UKIDSS) UDS survey fields. We find that, by modelling the H₁₆₀ image of each galaxy with a combination of a de Vaucouleurs bulge (Sérsic index n = 4) and an exponential disc (n = 1), we can then …

The Decomposed Bulge And Disc Size–Mass Relations Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo, E. J. Mcgrath

Physics and Astronomy Faculty Publications

We have constructed a mass-selected sample of M_* > 10¹¹ M_⊙ galaxies at 1 < z < 3 in the CANDELS UKIDSS UDS and COSMOS fields and have decomposed these systems into their separate bulge and disc components according to their H₁₆₀-band morphologies. By extending this analysis to multiple bands, we have been able to conduct individual bulge and disc component SED fitting which has provided us with stellar-mass and star formation rate estimates for the separate bulge and disc components. Having utilized the new decomposed stellar-mass estimates, we confirm that the bulge components display a stronger size evolution than the discs. The median sizes of the bulge components is 3.09 ± 0.20 times smaller than similarly massive local galaxies over the …

A Spectroscopic Survey Of Wise -Selected Obscured Quasars With The Southern African Large Telescope, Kevin N. Hainline, Ryan C. Hickox, Christopher M. Carroll, Adam D. Myers

Dartmouth Scholarship

We present the results of an optical spectroscopic survey of a sample of 40 candidate obscured quasars identified on the basis of their mid-infrared emission detected by the Wide-Field Infrared Survey Explorer (WISE). Optical spectra for this survey were obtained using the Robert Stobie Spectrograph on the Southern African Large Telescope. Our sample was selected with WISE colors characteristic of active galactic nuclei (AGNs), as well as red optical to mid-IR colors indicating that the optical/UV AGN continuum is obscured by dust. We obtain secure redshifts for the majority of the objects that comprise our sample (35/40), and …

Seqassist: A Novel Toolkit For Preliminary Analysis Of Next-Generation Sequencing Data, Yan Peng, Andrew S. Maxwell, Natalie D. Barker, Jennifer G. Laird, Alan J. Kennedy, Nan Wang, Chaoyang Zhang, Ping Gong

Faculty Publications

Background: While next-generation sequencing (NGS) technologies are rapidly advancing, an area that lags behind is the development of efficient and user-friendly tools for preliminary analysis of massive NGS data. As an effort to fill this gap to keep up with the fast pace of technological advancement and to accelerate data-to-results turnaround, we developed a novel software package named SeqAssist ("Sequencing Assistant" or SA).

Results: SeqAssist takes NGS-generated FASTQ files as the input, employs the BWA-MEM aligner for sequence alignment, and aims to provide a quick overview and basic statistics of NGS data. It consists of three separate workflows: …

Sigma Gamma Epsilon Undergraduate Research, Larry E. Davis

The Compass: Earth Science Journal of Sigma Gamma Epsilon

Fifty-two abstracts of student-authored research have been accepted for presentation in the Sigma Gamma Epsilon Undergraduate Research poster session at the Geological Society of America annual meeting in Vancouver, British Columbia, Canada. The poster session will be held on Tuesday, 21 October 2014, 9:00 AM to 6:30 PM, in the Vancouver Convention Centre-West Exhibition Hall C. Authors will be present from 9:00 to 11:00 AM, and 5:00 to 6:30 PM.

Optical Counterparts Of Two Fermi Millisecond Pulsars: Psr J1301+0833 And Psr J1628–3205, Miao Li, Jules P. Halpern, John R. Thorstensen

Dartmouth Scholarship

Using the 1.3 m and 2.4 m Telescopes of the MDM Observatory, we identified the close companions of two eclipsing millisecond radio pulsars that were discovered by the Green Bank Telescope in searches of Fermi Gamma-ray Space Telescope sources, and measured their light curves. PSR J1301+0833 is a black widow pulsar in a 6.5 hr orbit whose companion star is strongly heated on the side facing the pulsar. It varies from R = 21.8 to R > 24 around the orbit. PSR J1628–3205 is a "redback," a nearly Roche-lobe-filling system in a 5.0 hr orbit whose optical modulation in the range …

The Assignment Problem And A Suboptimal Solution Technique, William Barry Gregory

William A. Gregory

"A technique is presented which finds a fast suboptimal solution to the assignment problem. This same technique is then applied to two large dynamic programming problems for which the optimal solution is not known. These examples illustrate how easily this technique can be applied and that it is better than most optimizing techniques because it is fast, cheap and only minor hand calculations are needed. The effect of different initial solutions and their value are compared and it is found that the initial solution is not as significant in a suboptimal technique as in an optimizing technique. The initial solution …

Exonest: Bayesian Model Selection Applied To The Detection And Characterization Of Exoplanets Via Photometric Variations, Ben Placek, Kevin H. Knuth, Daniel Angerhausen

Physics Faculty Scholarship

EXONEST is an algorithm dedicated to detecting and characterizing the photometric signatures of exoplanets, which include reflection and thermal emission, Doppler boosting, and ellipsoidal variations. Using Bayesian inference, we can test between competing models that describe the data as well as estimate model parameters. We demonstrate this approach by testing circular versus eccentric planetary orbital models, as well as testing for the presence or absence of four photometric effects. In addition to using Bayesian model selection, a unique aspect of EXONEST is the potential capability to distinguish between reflective and thermal contributions to the light curve. A case study is …

Self-Organizing The Space Of Vocal Imitations, Davide Rocchesso, Davide Andrea Mauro Phd

Computer Sciences and Electrical Engineering Faculty Research

The human voice is a powerful instrument for producing sound sketches. The sonic space that can be spanned with the voice is vast and complex and, therefore, it is difficult to organize and explore. In this contribution, we report on our attempts at extracting the principal components from a database of 152 short excerpts of vocal imitations. We describe each excerpt by a set of statistical audio features and by a measure of similarity of the envelope to a small number of prototype envelopes. We apply k-means clustering on a space whose dimensionality has been reduced by singular value decomposition, …

Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors, J. J. Yen, B. Shank, Betty A. Young, Blas Cabrera, P. L. Brink, M. Cherry, J. M. Kreikebaum, R. Moffatt, P. Redl, A. Tomada, E. C. Tortorici

Physics

We report on experimental studies of phonon sensors which utilize quasiparticle diffusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach. These studies allow the design of phonon sensors with improved performance.

An Investigation Of The Dayton Regional Stem School Public-Private Partnerships, Kimberly S. Poole

CCE Theses and Dissertations

This dissertation study documents in-depth the exploration of the Public Private Partnerships (PPPs) between the Dayton Regional STEM School (DRSS) and their industry partners as well as the establishment of a framework for evaluating and assessing PPPs. The public-private partnership agreements were studied in order to answer the over-arching research question: How is an effective public-private partnership established, assessed, and evaluated in education? A descriptive case study methodology was used to study DRSS' public-private partnership agreements to determine if goals and objectives were established and whether or not the partnerships met those goals and objectives. This case study also included …

Distributed Owl El Reasoning: The Story So Far, Raghava Mutharaju, Pascal Hitzler, Prabhaker Mateti

Computer Science and Engineering Faculty Publications

Automated generation of axioms from streaming data, such as traffic and text, can result in very large ontologies that single machine reasoners cannot handle. Reasoning with large ontologies requires distributed solutions. Scalable reasoning techniques for RDFS, OWL Horst and OWL 2 RL now exist. For OWL 2 EL, several distributed reasoning approaches have been tried, but are all perceived to be inefficient. We analyze this perception. We analyze completion rule based distributed approaches, using different characteristics, such as dependency among the rules, implementation optimizations, how axioms and rules are distributed. We also present a distributed queue approach for the classification …

Information Security Newsletter

Information Security Newsletter

No abstract provided.

Near Horizon Geometry Of Strings Ending On Intersecting D8/D4-Branes, J. Estes, D. Krym, B. Van Pol

Publications and Research

We consider solutions of massive IIA supergravity corresponding to the half- BPS intersection of D8/D4-branes with fundamental strings. The 1 + 1-dimensional intersection preserves the symmetry D(2, 1; ; 1) × SO(4). We give a reduction and partial integration of the BPS equations for this symmetry group. We then specialize to the cases of enhanced supersymmetry corresponding to = −1/2,−2 or = 1. In the first case, we show that the only solution with enhanced symmetry is given by the AdS6 geometry describing the near horizon geometry of D8/D4-branes in the presence of an O8-plane. In the second case, we …

Beyond Sustainability: A New Conceptual Model, Molly Kerby, Gayle Mallinger

Faculty Publications

Over the last few decades, the notion of sustainability has become an interdisciplinary buzz word. Sustainability has been an integrative concept that includes three constructs or pillars: a) social; b) economic; and c) ecological. Until recently, theoretical approaches based on the three pillars approach have operated in silos rather than exploring the interconnectedness of the constructs. Few models have moved beyond the idea that logical relations exist among the constructs (social, economic, and ecological) to consider factors external to communities, nor have they examined the internal socio-economic factors that influence positive outcomes. While this conceptualization has raised awareness about the …

Gravitational Waves From Individual Supermassive Black Hole Binaries In Circular Orbits: Limits From The North American Nanohertz Observatory For Gravitational Waves, Z. Arzoumanian, A. Brazier, S. Burke-Spolaor, S. J. Chamberlin, S. Chatterjee, J. M. Cordes, P. B. Demorest, X. Deng, T. Dolch, J. A. Ellis, R. D. Ferdman, N. Garver-Daniels, Fredrick A. Jenet, G. Jones, V. M. Kaspi, M. Koop, M. T. Lam, T. J.W. Lazio, A. N. Lommen, D. R. Lorimer, Jing Luo, R. S. Lynch, D. R. Madison, M. A. Mclaughlin, S. T. Mcwilliams, D. J. Nice, N. Palliyaguru, T. T. Pennucci, S. M. Ransom, A. Sesana

Physics and Astronomy Faculty Publications and Presentations

We perform a search for continuous gravitational waves from individual supermassive black hole binaries using robust frequentist and Bayesian techniques. We augment standard pulsar timing models with the addition of time-variable dispersion measure and frequency variable pulse shape terms. We apply our techniques to the Five Year Data Release from the North American Nanohertz Observatory for Gravitational Waves. We find that there is no evidence for the presence of a detectable continuous gravitational wave; however, we can use these data to place the most constraining upper limits to date on the strength of such gravitational waves. Using the full 17 …

Optimization Of Nanograv's Time Allocation For Maximum Sensitivity To Single Sources, Brian Christy, Ryan Anella, Andrea N. Lommen, Lee Samuel Finn, Richard S. Camuccio, Emma Handzo

Physics and Astronomy Faculty Publications and Presentations

Pulsar timing arrays (PTAs) are a collection of precisely timed millisecond pulsars (MSPs) that can search for gravitational waves (GWs) in the nanohertz frequency range by observing characteristic signatures in the timing residuals. The sensitivity of a PTA depends on the direction of the propagating GW source, the timing accuracy of the pulsars, and the allocation of the available observing time. The goal of this paper is to determine the optimal time allocation strategy among the MSPs in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) for a single source of GW under a particular set of assumptions. We …

Suppression Of Optical Damage At 532 Nm In Holmium Doped Congruent Lithium Niobate, Eftihia Barnes, Nathan H. O'Connell, Nicolas R. Balli, Madhab Pokhrel, Anush Movsesyan, Edvard Kokanyan, Dhiraj K. Sardar

Physics and Astronomy Faculty Publications and Presentations

Optical damage experiments were carried out in a series of Holmium doped congruent lithium niobate (Ho:cLN) crystals as a function of dopant concentration and laser intensity. The light induced beam distortion was recorded with a camera and a detector under the pseudo-Zscan configuration. At 532 nm, strong suppression of the optical damage was observed for the 0.94 mol. % doped crystal. Increased resistance to optical damage was also observed at 488 nm. The suppression of the optical damage is predominantly attributed to the reduction of the Nb antisites due to the holmium doping.

The Lyman Alpha Reference Sample: Iii. Properties Of The Neutral Ism From Gbt And Vla Observations, Stephen Pardy, John Cannon, Göran Östlin, Matthew Hayes, Thøger Rivera-Thorsen, Andreas Sandberg, Angela Adamo, Emily Freeland, E. Herenz, Lucia Guaita, Daniel Kunth, Peter Laursen, J. Mas-Hesse, Jens Melinder, Ivana Orlitova, Hecto Otí-Floranes, Johannes Puschnig, Daniel Schaerer, Anne Verhamme

John Cannon

No abstract provided.