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2013

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Articles 8221 - 8250 of 11462

Full-Text Articles in Physical Sciences and Mathematics

Assessment Of Freshwater Mussel Communities Of Small Stream Mouths Along Lake Erie, Trevor J. Prescott Jan 2013

Assessment Of Freshwater Mussel Communities Of Small Stream Mouths Along Lake Erie, Trevor J. Prescott

ETD Archive

Invasion of lakes and rivers by dreissenid mussels pushed out native species, particularly freshwater mussels in the Unionidae, across the northern hemisphere, and perhaps most infamously, within the Laurentian Great Lakes. However, several coastal areas along the shallowest of these lakes, Lake Erie, may be refugia for native species, but the conditions under which native species persist are unknown. I surveyed river mouths of small streams along the Lake Erie coastline and compared species abundance to land use assessed by remote sensing techniques and to standard measures of water chemistry. Sampling focused on stream zones influenced by lake-water levels for …


Nos Oxygenase-Mediated Nitroalkane Catalytic Reduction: Impact On Nos Reaction, Praneeth Ivan Joel Fnu Jan 2013

Nos Oxygenase-Mediated Nitroalkane Catalytic Reduction: Impact On Nos Reaction, Praneeth Ivan Joel Fnu

ETD Archive

Organic nitroalkanes are used in many industries and for a variety of purposes. Their use is expanding and is steadily claiming new territories in our immediate environment. Some nitroalkanes, when they enter the human body, can be harmful as such or can be activated to generate reactive intermediates with known detrimental effects. P450 enzymes are known for metabolizing a variety of drugs and substances including organic nitroalkanes. Nitric oxide synthases (NOS) exhibit some similarities to P450 metalloenzymes and their potential interaction with nitroalkanes as xenobiotics is not well known. The present study investigates the effect of nitroalkanes on the catalytic …


Automated Spectral Identification Of Materials Using Spectral Identity Mapping, Robert William Cannon Jan 2013

Automated Spectral Identification Of Materials Using Spectral Identity Mapping, Robert William Cannon

ETD Archive

With increased use of Raman spectroscopic instrumentation for material analysis there has also been an increase in the amount of acquired Raman spectral data. Because of this, there is a clear need to develop and implement advanced spectral analysis techniques. This is especially true in cases where limited reference data may be available and large data sets need to be interpreted. Raman spectral analysis and standardization techniques, along with a foundation for a comprehensive repository of Raman spectral data, will be described in this thesis. The main focus will be automated analysis and standardization of Raman spectral data using spectral …


Origin Of The Low Frequency Radiation Emitted By Radiative Polaritons Excited By Infrared Radiation In Planar La2o3 Films, Anita J. Vincent-Johnson, Yosep Schwab, Harkirat S. Mann, Mathieu Francoeur, James S. Hammonds Jr., Giovanna Scarel Jan 2013

Origin Of The Low Frequency Radiation Emitted By Radiative Polaritons Excited By Infrared Radiation In Planar La2o3 Films, Anita J. Vincent-Johnson, Yosep Schwab, Harkirat S. Mann, Mathieu Francoeur, James S. Hammonds Jr., Giovanna Scarel

Department of Physics and Astronomy - Faculty Scholarship

Upon excitation in thin oxide films by infrared radiation, radiative polaritons are formed with complex angular frequency ω, according to the theory of Kliewer and Fuchs (1966 Phys. Rev. 150 573). We show that radiative polaritons leak radiation with frequency ωi to the space surrounding the oxide film. The frequency ωi is the imaginary part of ω. The effects of the presence of the radiation leaked out at frequency ωi are observed experimentally and numerically in the infrared spectra of La2O3 films on silicon upon excitation by infrared radiation of the 0TH type radiative polariton. The frequency ωi is found …


On Multicomponent Derivative Nonlinear Schrodinger Equation Related To Symmetric Spaces, Tihomir Valchev Jan 2013

On Multicomponent Derivative Nonlinear Schrodinger Equation Related To Symmetric Spaces, Tihomir Valchev

Conference papers

We study derivative nonlinear Schrodinger equations related to symmetric spaces of the type A.III. We discuss the spectral properties of the corresponding Lax operator and develop the direct scattering problem connected to it. By applying an appropriately chosen dressing factor we derive soliton solutions to the nonlinear equation. We find the integrals of motion by using the method of diagonalization of Lax pair.


Remarks On Quadratic Bundles Related To Hermitian Symmetric Spaces, Tihomir Valchev Jan 2013

Remarks On Quadratic Bundles Related To Hermitian Symmetric Spaces, Tihomir Valchev

Conference papers

We consider quadratic bundles related to Hermitian symmetric spaces of the type SU(m+n)/S(U(m)\times U(n)). We discuss the spectral properties of scattering operator, develop the direct scattering problem associated with it and stress on the effect of reduction on these. By applying a modification of Zakharov-Shabat's dressing procedure we demonstrate how one can obtain reflectionless potentials. That way one is able to generate soliton solutions to the nonlinear evolution equations belonging to the integrable hierarchy associated with quadratic bundles under study.


Executive Summary — Teaching About Scientific Inquiry And The Nature Of Science Jan 2013

Executive Summary — Teaching About Scientific Inquiry And The Nature Of Science

Journal of Mathematics and Science: Collaborative Explorations

No abstract provided.


Superlinear Increase Of Photoluminescence With Excitation Intensity In Zn-Doped Gan, Michael A. Reshchikov, Anita J. Olsen, Marilyn F. Bishop, Tom Mcmullen Jan 2013

Superlinear Increase Of Photoluminescence With Excitation Intensity In Zn-Doped Gan, Michael A. Reshchikov, Anita J. Olsen, Marilyn F. Bishop, Tom Mcmullen

Physics Publications

We have observed a superlinear increase of photoluminescence (PL) intensity in a narrow range of excitation intensities for Zn-doped GaN. The characteristic intensity at which the abrupt increase occurs increases with increasing temperature. This is unlike the usual observations for defects in semiconductors in which the PL intensity increases linearly with excitation intensity, saturating at high intensity because defects become saturated with photogenerated charge carriers. The observed phenomenon is attributed to a redirection of electron and hole flow from nonradiative centers at low excitation intensity to a recombination path via the Zn-Ga acceptor at high excitation intensity. This is the …


Conical Intersection And Potential Energy Surface Features Of A Model Retinal Chromophore: Comparison Of Eom-Cc And Multireference Methods, Samer Gozem, Anna I. Krylov, Massimo Olivucci Jan 2013

Conical Intersection And Potential Energy Surface Features Of A Model Retinal Chromophore: Comparison Of Eom-Cc And Multireference Methods, Samer Gozem, Anna I. Krylov, Massimo Olivucci

Chemistry Faculty Publications

This work investigates the performance of equation-of-motion coupled-cluster (EOM-CC) methods for describing the changes in the potential energy surfaces of the penta-2,4-dieniminium cation, a reduced model of the retinal chromophore of visual pigments, due to dynamical electron correlation effects. The ground-state wave function of this model includes charge-transfer and diradical configurations whose weights vary along different displacements and are rapidly changing at the conical intersection between the ground and the first excited states, making the shape of the potential energy surface sensitive to a balanced description of nondynamical and dynamical correlation. Recently, variational (MRCISD) and perturbative (MRPT2) approaches for including …


A Study Of Product Dissection’S Impact On Engineering Creativity, Christine A. Toh, Scarlett Miller Jan 2013

A Study Of Product Dissection’S Impact On Engineering Creativity, Christine A. Toh, Scarlett Miller

Interdisciplinary Informatics Faculty Publications

Designers typically interact with products during the early stages of design to gain an understanding of the solution space. However, few studies have been conducted to understand how these practices affect idea generation which thereby limits our understanding of the utility of these methods. Therefore, the current study was conducted to understand designer-product interactions in order to develop recommendations for their use during the design process.


A Parallel Template For Implementing Filters For Biological Correlation Networks, Kathryn Dempsey Cooper, Vladimir Ufimtsev, Sanjukta Bhowmick, Hesham Ali Jan 2013

A Parallel Template For Implementing Filters For Biological Correlation Networks, Kathryn Dempsey Cooper, Vladimir Ufimtsev, Sanjukta Bhowmick, Hesham Ali

Interdisciplinary Informatics Faculty Publications

High throughput biological experiments are critical for their role in systems biology – the ability to survey the state of cellular mechanisms on the broad scale opens possibilities for the scientific researcher to understand how multiple components come together, and what goes wrong in disease states. However, the data returned from these experiments is massive and heterogeneous, and requires intuitive and clever computational algorithms for analysis. The correlation network model has been proposed as a tool for modeling and analysis of this high throughput data; structures within the model identified by graph theory have been found to represent key players …


A Highly Efficient Tio2-Xcx Nano-Heterojunction Photocatalyst For Visible-Light Induced Antibacterial Applications, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Georg Michlits, Suresh Pillai Jan 2013

A Highly Efficient Tio2-Xcx Nano-Heterojunction Photocatalyst For Visible-Light Induced Antibacterial Applications, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Georg Michlits, Suresh Pillai

Articles

Visible-light-induced antibacterial activity of carbon-doped anatase-brookite titania nano-heterojunction photocatalysts are reported for the first time. These heterostructures were prepared using a novel low temperature (100 °C) non-hydrothermal low power microwave (300 W) assisted method. Formation of interband C 2p states was found to be responsible for the band gap narrowing of the carbon doped heterojunctions. The most active photocatalyst obtained after 60 minutes of microwave irradiation exhibits a 2-fold higher visible-light induced photocatalytic activity in contrast to the standard commercial photocatalyst Evonik-Degussa P-25. Staphylococcus aureus inactivation rate constant for carbon-doped nano-heterojunctions and the standard photocatalyst was 0.0023 and -0.0081 min …


Knowledge Extraction From Survey Data Using Neural Networks, Khan Imran, Arun Kulkarni Jan 2013

Knowledge Extraction From Survey Data Using Neural Networks, Khan Imran, Arun Kulkarni

Computer Science Faculty Publications and Presentations

Surveys are an important tool for researchers. It is increasingly important to develop powerful means for analyzing such data and to extract knowledge that could help in decision-making. Survey attributes are typically discrete data measured on a Likert scale. The process of classification becomes complex if the number of survey attributes is large. Another major issue in Likert-Scale data is the uniqueness of tuples. A large number of unique tuples may result in a large number of patterns. The main focus of this paper is to propose an efficient knowledge extraction method that can extract knowledge in terms of rules. …


Impact Of Pre-Columbian Agriculture, Climate Change, And Tectonic Activity Inferred From A 5,700-Year Paleolimnological Record From Lake Nicaragua, Jennifer E. Slate, Thomas C. Johnson, Ted C. Moore Jan 2013

Impact Of Pre-Columbian Agriculture, Climate Change, And Tectonic Activity Inferred From A 5,700-Year Paleolimnological Record From Lake Nicaragua, Jennifer E. Slate, Thomas C. Johnson, Ted C. Moore

Biology Faculty Publications

Lake Nicaragua, the largest lake in Central America, is a promising site for paleolimnological study of past climate change, tectonic and volcanic activity, and pre-Columbian agriculture in the region. It is near the northern limit of the Intertropical Convergence Zone (ITCZ), which brings the rainy season to the tropics, so effects of decreasing precipitation due to southern migration of the ITCZ through the Holocene should be observable. Because fault zones and an active volcano lie within the lake, the long-term impact of tectonic and volcanic activity can also be examined. Finally, the fertile volcanic soils near the lake may have …


Modeling Terrestrial Gamma Ray Flashes Produced By Relativistic Feedback Discharges, Ningyu Liu, Joseph R. Dwyer Jan 2013

Modeling Terrestrial Gamma Ray Flashes Produced By Relativistic Feedback Discharges, Ningyu Liu, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

This paper reports a modeling study of terrestrial gamma ray flashes (TGFs) produced by relativistic feedback discharges. Terrestrial gamma ray flashes are intense energetic radiation originating from the Earth’s atmosphere that has been observed by spacecraft. They are produced by bremsstrahlung interactions of energetic electrons, known as runaway electrons, with air atoms. An efficient physical mechanism for producing large fluxes of the runaway electrons to make the TGFs is the relativistic feedback discharge, where seed runaway electrons are generated by positrons and X-rays, products of the discharge itself. Once the relativistic feedback discharge becomes self-sustaining, an exponentially increasing number of …


The Balm Copula, Boyan N. Dimitrov, Nikolai Kolev Jan 2013

The Balm Copula, Boyan N. Dimitrov, Nikolai Kolev

Mathematics Publications

The class of probability distributions possessing the almost-lack-of-memory property appeared about 20 years ago. It reasonably took place in research and modeling, due to its suitability to represent uncertainty in periodic random environment. Multivariate version of the almost-lack-of-memory property is less known, but it is not less interesting. In this paper we give the copula of the bivariate almost-lack-of-memory (BALM) distributions and discuss some of its properties and applications. An example shows how the Marshal-Olkin distribution can be turned into BALM and what is its copula.


Colloidal Nano-Apatite Particles With Active Luminescent And Magentic Properties For Biotechnology Applications, Rajendra Kasinath, Kumar Ganesan Jan 2013

Colloidal Nano-Apatite Particles With Active Luminescent And Magentic Properties For Biotechnology Applications, Rajendra Kasinath, Kumar Ganesan

Environmental Engineering

Colloidal Nano-apatite Particles with Active Luminescent and Magentic Properties for Biotechnology Applications. The synthesis of functional nano-materials is a burgeoning field that has produced remarkable and consistent breakthroughs over the last two decades. Individual particles have become smaller and shown potential for well defined functionality. However, there are still unresolved problems, a primary one being the loss of functionality and novelty due to uncontrolled aggregation driven by surface energy considerations. As such the first design criteria to harness the true potential of nanoparticles is to prevent unwanted agglomeration by: (1) improving, and, if possible, (2) controlling aggregation behavior. This requires …


Core Ironclad, Peter-Michael Osera, Richard A. Eisenberg, Christian Delozier, Santosh Nagarakatte, Milo M.K. Martin, Steve Zdancewic Jan 2013

Core Ironclad, Peter-Michael Osera, Richard A. Eisenberg, Christian Delozier, Santosh Nagarakatte, Milo M.K. Martin, Steve Zdancewic

Computer Science Faculty Research and Scholarship

Core Ironclad is a core calculus that models the salient features of Ironclad C++, a library-augmented type-safe subset of C++. We give an overview of the language including its definition and key design points. We then prove type safety for the language and use that result to show that the pointer lifetime invariant, a key property of Ironclad C++, holds within the system.


Closed Type Families With Overlapping Equations (Extended Version), Richard A. Eisenberg, Dimitrios Vytiniotis, Simon Peyton Jones, Stephanie Weirich Jan 2013

Closed Type Families With Overlapping Equations (Extended Version), Richard A. Eisenberg, Dimitrios Vytiniotis, Simon Peyton Jones, Stephanie Weirich

Computer Science Faculty Research and Scholarship

Open, type-level functions are a recent innovation in Haskell that move Haskell towards the expressiveness of dependent types, while retaining the look and feel of a practical programming language. This paper shows how to increase expressiveness still further, by adding closed type functions whose equations may overlap, and may have non-linear patterns over an open type universe. Although practically useful and simple to implement, these features go beyond conventional dependent type theory in some respects, and have a subtle metatheory.


System Fc With Explicit Kind Equality (Extended Version), Stephanie Weirich, Justin Hsu, Richard A. Eisenberg Jan 2013

System Fc With Explicit Kind Equality (Extended Version), Stephanie Weirich, Justin Hsu, Richard A. Eisenberg

Computer Science Faculty Research and Scholarship

System FC, the core language of the Glasgow Haskell Compiler, is an explicitly-typed variant of System F with first-class type equality proofs called coercions. This extensible proof system forms the foundation for type system extensions such as type families (type- level functions) and Generalized Algebraic Datatypes (GADTs). Such features, in conjunction with kind polymorphism and datatype promotion, support expressive compile-time reasoning.

However, the core language lacks explicit kind equality proofs. As a result, type-level computation does not have access to kind- level functions or promoted GADTs, the type-level analogues to expression-level features that have been so useful. In this paper, …


Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez Jan 2013

Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez

Forest Carbon Storage Study Documents

The Gordon Natural Area (GNA) serves as a natural laboratory for a range of class research projects. In a Geography Field Methods course led by Dr. Fritschle, students established five permanent carbon-study plots in 2008. Since then, students have returned to these plots to measure the carbon stock of standing trees in five plots located along a topographic gradient: floodplain, ridge-top, lower mid-slope, mid-slope and upper mid-slope. Using U.S. Forest Service established guidelines, all trees greater than 5 cm and up to 73 cm in diameter at breast height (DBH) were measured and identified within each 40 m circular plot. …


West Chester University Climate Action Plan: Carbon Neutral By 2025, Tim Lutz, Executive Director Of Facilities Management, Climate Action Planning Team Jan 2013

West Chester University Climate Action Plan: Carbon Neutral By 2025, Tim Lutz, Executive Director Of Facilities Management, Climate Action Planning Team

WCU Campus Sustainability Initiatives

WEST CHESTER UNIVERSITY PRESIDENT GREG WEISENSTEIN signed the American College and University Presidents’ Climate Commitment (ACUPCC) in October 2010, pledging the University to a series of actions that will ultimately reduce net greenhouse gas emissions to zero. In doing so we joined more than 600 institutions in expressing our deep concern about global warming. More importantly, we accepted the challenge to provide leadership in our own community by “modeling ways to minimize global warming emissions, and by providing the knowledge and the educated graduates to achieve climate neutrality.” Since 2010 we have completed an inventory of greenhouse gas emissions (GHG), …


Water Quality Monitoring In The Gordon Natural Area, East Branch Plum Run, Charles V. Shorten Jan 2013

Water Quality Monitoring In The Gordon Natural Area, East Branch Plum Run, Charles V. Shorten

Plum Run Water Quality Study Documents

No abstract provided.


Geology Of The Gordon Natural Area: Making Mountains Out Of Molehills - A Service-Learning Investigation By Students In Ess 405/505 Petrology, Fall 2009–2012, Leeann Srogi, John Kost Jan 2013

Geology Of The Gordon Natural Area: Making Mountains Out Of Molehills - A Service-Learning Investigation By Students In Ess 405/505 Petrology, Fall 2009–2012, Leeann Srogi, John Kost

Gordon Natural Area Geology Studies Documents

No abstract provided.


Geo402/585: Field Methods; Labs 4-5 Gordon Natural Area Carbon Stock Pilot Study, Joy Fritschle Jan 2013

Geo402/585: Field Methods; Labs 4-5 Gordon Natural Area Carbon Stock Pilot Study, Joy Fritschle

Gordon Natural Area-related Curricula Documents

No abstract provided.


The Method Of Lagrange Multipliers, William Trench Jan 2013

The Method Of Lagrange Multipliers, William Trench

Mathematics Faculty Research

This is a supplement to the author's "Introduction to Real Analysis." It has been judged to meet the evaluation criteria set by the Editorial Board of the American Institute of Mathematics in connection with the Institute's Open Textbook Initiative. It may be copied, modified, redistributed, translated, and built upon subject to the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. A complete instructor's solution manual is available by email to wtrench@trinity.edu, subject to verification of the requestor's faculty status.


Functions Defined By Improper Integrals, William Trench Jan 2013

Functions Defined By Improper Integrals, William Trench

Mathematics Faculty Research

This is a supplement to the author's Introduction to Real Analysis. It has been judged to meet the evaluation criteria set by the Editorial Board of the American Institute of Mathematics in connection with the Institute's Textbook Initiative. It may be copied, modified, redistributed, translated, and built upon subject to the Creative Commons license Attribution-NonCommercial-ShareAlike 3.0 Unported License. A complete instructor's solution manual is available by email to wtrench@trinity.edu subject to verification of the requestor's faculty status.


Water Conservation In San Antonio, Tx: The Economics Of Water Pricing And The Effectiveness Of The Watersaver Landscape Rebate, Mark Wilkinson, Mitch Hagney, Yemi Idowu, Megan Miller Jan 2013

Water Conservation In San Antonio, Tx: The Economics Of Water Pricing And The Effectiveness Of The Watersaver Landscape Rebate, Mark Wilkinson, Mitch Hagney, Yemi Idowu, Megan Miller

Geosciences Student Works

We address the effort to decrease residential water use in San Antonio, Texas, because recent droughts have made water conservation a high priority there. Since the city’s water utility—the San Antonio Water System (SAWS)—maintains water prices below economically efficient levels, demand is outstripping supply. To address this problem, we apply microeconomic analysis to the utility’s residential water pricing structure and the drought restrictions it imposes. We make recommendations for incentivizing water conservation in high-volume consumers by increasing the progressivity of SAWS pricing policies. SAWS also offers water conservation rebates, such as the WaterSaver Landscape Rebate, whose effectiveness we analyze herein. …


Fracking Up The Future: Recommendations For Hydraulic Fracturing In Gonzales County, Tx, Jennifer Ince, Philip Queller, Devon Rood, Kara Shervanick Jan 2013

Fracking Up The Future: Recommendations For Hydraulic Fracturing In Gonzales County, Tx, Jennifer Ince, Philip Queller, Devon Rood, Kara Shervanick

Geosciences Student Works

Despite its economic appeal, hydraulic fracturing (fracking) has sparked bitter controversy. Allegations of toxic fracking fluids and fracking-induced droughts have made fracking a major public health and environmental concern in the United States. Fracking is dependent on local conditions to a large degree; therefore, we focus on Gonzales County, located within Texas’ Eagle Ford shale region, in order to address county-specific concerns. However, our findings can be applied to help create sustainable practices for fracking in any context. Unfortunately, regulations are limited due to the 2005 Energy Policy Act that prevents federal agencies, including the EPA, from regulating fracking. In …


An Exploration Of The Development And Proliferation Of Hydraulic Fracturing, Ellee G. Cook, Travis Dodson, Kara Shervanick, Alice Whitten Jan 2013

An Exploration Of The Development And Proliferation Of Hydraulic Fracturing, Ellee G. Cook, Travis Dodson, Kara Shervanick, Alice Whitten

Environmental Studies Student Works

No abstract provided.