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Articles 151411 - 151440 of 294596

Full-Text Articles in Physical Sciences and Mathematics

Gone With The Wind: Soil Moisture Effects On Gaseous Nitrogen Removal From Wastewater, Faith L. Anderson May 2016

Gone With The Wind: Soil Moisture Effects On Gaseous Nitrogen Removal From Wastewater, Faith L. Anderson

Senior Honors Projects

Onsite wastewater treatment systems (OWTS), or septic systems, release nitrogen (N), which can be detrimental to aquatic ecosystems. The final step in the treatment of wastewater is dispersal onto a drainfield, where it percolates through the soil. Part of the N is removed from wastewater and released into the atmosphere as N2 and N2O by denitrification, which requires anoxic conditions. Previous studies looking at the effect of soil water-filled pore space (WFPS) on denitrification using clean water with a high level of dissolved O2 (DO) have identified a minimum of 60% WFPS for denitrification to take …


A Physiologically-Based Pharmacokinetic Model For The Antibiotic Levofloxacin, Paezha M. Mccartt May 2016

A Physiologically-Based Pharmacokinetic Model For The Antibiotic Levofloxacin, Paezha M. Mccartt

Undergraduate Honors Theses

Levofloxacin is in a class of antibiotics known as fluoroquinolones, which treat infections by killing the bacteria that cause them. A physiologically-based pharmacokinetic (PBPK) model was developed to investigate the uptake, distribution, and elimination of Levofloxacin after a single dose. PBPK modeling uses parameters such as body weight, blood flow rates, partition coefficients, organ volumes, and several other parameters in order to model the distribution of a particular drug throughout the body. Levofloxacin is only moderately bound in human blood plasma, and, thus, for the purposes of this paper, linear bonding is incorporated into the model because the free or …


Star Formation In Ring Galaxies, Susan C. Olmsted May 2016

Star Formation In Ring Galaxies, Susan C. Olmsted

Undergraduate Honors Theses

Ring galaxies are specific types of interacting galaxies in which a smaller galaxy has passed through the center of the disk of another larger galaxy. The intrusion of the smaller galaxy causes the structure of the larger galaxy to compress as the smaller galaxy falls through, and to recoil back after the smaller galaxy passes through, hence the ring-like shape. In our research, we studied the star-forming regions of a sample of ring galaxies and compared to those of other interacting galaxies and normal galaxies. Using UV, optical, and IR archived images in twelve wavelengths from three telescopes, we analyzed …


Extracting (1,3/1,6)-Β-Glucans From Saccharomyces Cerevisiae: A Fungal Immunotherapeutic, James C. Elliott May 2016

Extracting (1,3/1,6)-Β-Glucans From Saccharomyces Cerevisiae: A Fungal Immunotherapeutic, James C. Elliott

Undergraduate Honors Theses

The goal of this research was the development of a method to extract pure (1,3/1,6)-β-glucans from Saccharomyces cerevisiae. These β-glucans are of pharmaceutical importance because an animal’s immune system can recognize glucan molecules, and these molecules can act as immunomodulators, essentially turning on the immune system. The problem in the past has been that previously published methods produce β-glucans with low side chain lengths and few branching occurrences. This issue was tackled by a multivariable approach that reduced extraction steps, initial sample size, and concentrations of reagents used. This method has been shown to produce greater yields of β-glucans while …


Structural Variations Involving S-Block Metal Pyrazolates, Joshua Woods May 2016

Structural Variations Involving S-Block Metal Pyrazolates, Joshua Woods

Renée Crown University Honors Thesis Projects - All

Alkali and alkaline earth metal organometallics have been sought after for a variety of applications such as in electronic devices produced by novel metal organic chemical vapor deposition precursors, catalysts and as synthetic reagents. Despite significant advances in synthetic techniques, the chemistry of the highly reactive s-block metals is still relatively unexplored. It is difficult to predict properties, structure and binding modes of these compounds due to a number of factors including enhanced reactivity and tendency to aggregation due to the large metal diameter. On the other hand, many of the s-block metals are earth abundant and environmentally friendly, …


Polynomials With No Zeros On A Face Of The Bidisk, Jeffrey S. Geronimo, Plamen Iliev, Greg Knese May 2016

Polynomials With No Zeros On A Face Of The Bidisk, Jeffrey S. Geronimo, Plamen Iliev, Greg Knese

Mathematics Faculty Research

We present a Hilbert space geometric approach to the problem of characterizing the positive bivariate trigonometric polynomials that can be represented as the square of a two variable polynomial possessing a certain stability requirement, namely no zeros on a face of the bidisk. Two different characterizations are given using a Hilbert space structure naturally associated to the trigonometric polynomial; one is in terms of a certain orthogonal decomposition the Hilbert space must possess called the “split-shift orthogonality condition” and another is an operator theoretic or matrix condition closely related to an earlier characterization due to the first two authors. This …


Employing Synergetic Effect Of Doping And Thin Film Coating To Boost The Performance Of Lithium-Ion Battery Cathode Particles, Rajankumar L. Patel, Yingbing Jiang, Amitava Choudhury, Xinhua Liang May 2016

Employing Synergetic Effect Of Doping And Thin Film Coating To Boost The Performance Of Lithium-Ion Battery Cathode Particles, Rajankumar L. Patel, Yingbing Jiang, Amitava Choudhury, Xinhua Liang

Chemistry Faculty Research & Creative Works

Atomic layer deposition (ALD) has evolved as an important technique to coat conformal protective thin films on cathode and anode particles of lithium ion batteries to enhance their electrochemical performance. Coating a conformal, conductive and optimal ultrathin film on cathode particles has significantly increased the capacity retention and cycle life as demonstrated in our previous work. In this work, we have unearthed the synergetic effect of electrochemically active iron oxide films coating and partial doping of iron on LiMn1.5 Ni0.5O4 (LMNO) particles. The ionic Fe penetrates into the lattice structure of LMNO during the ALD process. …


The Implicit Function Theorem And Free Algebraic Sets, Jim Agler, John E. Mccarthy May 2016

The Implicit Function Theorem And Free Algebraic Sets, Jim Agler, John E. Mccarthy

Mathematics Faculty Research

We prove an implicit function theorem for non-commutative functions. We use this to show that if p ( X;Y ) is a generic non-commuting polynomial in two variables, and X is a generic matrix, then all solutions Y of p ( X;Y ) = 0 will commute with X


Approximating The Performance Of A "Last Mile" Transportation System, Hai Wang, Amedeo Odoni May 2016

Approximating The Performance Of A "Last Mile" Transportation System, Hai Wang, Amedeo Odoni

Research Collection School Of Computing and Information Systems

The Last Mile Problem (LMP) refers to the provision of travel service from the nearest public transportation node to a home or office. We study the supply side of this problem in a stochastic setting, with batch demands resulting from the arrival of groups of passengers who request last-mile service at urban rail stations or bus stops. Closedform approximations are derived for the performance of Last Mile Transportations Systems as a function of the fundamental design parameters of such systems. An initial set of results is obtained for the case in which a fleet of vehicles of unit capacity provides …


Reinforcement Learning Framework For Modeling Spatial Sequential Decisions Under Uncertainty: (Extended Abstract), Truc Viet Le, Siyuan Liu, Hoong Chuin Lau May 2016

Reinforcement Learning Framework For Modeling Spatial Sequential Decisions Under Uncertainty: (Extended Abstract), Truc Viet Le, Siyuan Liu, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We consider the problem of trajectory prediction, where a trajectory is an ordered sequence of location visits and corresponding timestamps. The problem arises when an agent makes sequential decisions to visit a set of spatial locations of interest. Each location bears a stochastic utility and the agent has a limited budget to spend. Given the agent's observed partial trajectory, our goal is to predict the remaining trajectory. We propose a solution framework to the problem considering both the uncertainty of utility and the budget constraint. We use reinforcement learning (RL) to model the underlying decision processes and inverse RL to …


Using Abstractions To Solve Opportunistic Crime Security Games At Scale, Chao Zhang, Victor Bucarey, Ayan Mukhopadhyay, Arunesh Sinha, Qian. Yundi, Yevgeniy Vorobeychik, Milind Tambe May 2016

Using Abstractions To Solve Opportunistic Crime Security Games At Scale, Chao Zhang, Victor Bucarey, Ayan Mukhopadhyay, Arunesh Sinha, Qian. Yundi, Yevgeniy Vorobeychik, Milind Tambe

Research Collection School Of Computing and Information Systems

In this paper, we aim to deter urban crime by recommending optimal police patrol strategies against opportunistic criminals in large scale urban problems. While previous work has tried to learn criminals' behavior from real world data and generate patrol strategies against opportunistic crimes, it cannot scale up to large-scale urban problems. Our first contribution is a game abstraction framework that can handle opportunistic crimes in large-scale urban areas. In this game abstraction framework, we model the interaction between officers and opportunistic criminals as a game with discrete targets. By merging similar targets, we obtain an abstract game with fewer total …


Exogenous Polyunsaturated Fatty Acid (Pufa) Scavenging Affects Phospholipid Profiles And Virulence Phenotypes In Vibrio Cholerae And Vibrio Parahaemolyticus, Anna Moravec May 2016

Exogenous Polyunsaturated Fatty Acid (Pufa) Scavenging Affects Phospholipid Profiles And Virulence Phenotypes In Vibrio Cholerae And Vibrio Parahaemolyticus, Anna Moravec

Honors Theses

AIM: This research had two primary objectives. First, this study sought to determine whether or not exposing Vibrio cholerae and Vibrio parahaemolyticus to polyunsaturated fatty acids (PUFAs) would lead to changes in their respective phospholipid profiles. Secondly, if membrane remodeling occurred, this study sought to determine the impact of membrane modifications on bacterial fitness by evaluating their effect on membrane permeability, biofilm formation, and response to stresses. METHODS: The Bligh and Dyer method was used to extract bacterial lipids, which were subsequently analyzed via thin-layer chromatography (TLC). The effect of fatty acids on bacterial fitness was assessed using stress, biofilm, …


A Fractional Boundary Value Problem, Grant Yost May 2016

A Fractional Boundary Value Problem, Grant Yost

Honors Theses

We consider a fractional boundary value problem with various boundary conditions. This boundary value problem has two components, one fractional derivative of alpha degree with alpha between n-1 and n, and a fractional derivative of beta degree with beta between 0 and n-2. We prove existence and uniqueness of solutions, and show some examples that were found using a MATLAB simulation.


Measuring Phytophthora Resistance Phenotypes In Segregating Testcross Families Of Hybrid American Chestnut Trees, Anna C. Robinson May 2016

Measuring Phytophthora Resistance Phenotypes In Segregating Testcross Families Of Hybrid American Chestnut Trees, Anna C. Robinson

Honors Theses

Phytophthora root rot (PRR), caused by the oomycete Phytophthora cinnamomi Rands, is a formidable obstacle to the restoration of Castanea dentata Marsh. commonly known as the American chestnut. Genetic resistance to PRR has been observed in Asian species of chestnut including C. mollissima Blume, and in interspecific hybrids between C. mollissima and C. dentata. We hypothesized that root rot resistance alleles would segregate in a 1:1 ratio within progeny of crosses between PRR resistant F1 hybrids and PRR-susceptible American chestnut trees (first-backcrosses), and that PRR resistance could be successfully passed down to all families of first-backcross hybrids. To test these …


The Simple Zeros Of The Riemann Zeta-Function, Melissa N. Miller May 2016

The Simple Zeros Of The Riemann Zeta-Function, Melissa N. Miller

Honors Theses

There have been many tables of primes produced since antiquity. In 348 BC Plato studied the divisors of the number 5040. In 1202 Fibonacci gave an example with a list of prime numbers up to 100. By the 1770's a table of number factorizations up to two million was constructed. In 1859 Riemann demonstrated that the key to the deeper understanding of the distribution of prime numbers lies in the study of a certain complex-valued function, called the zeta-function. In 1973 Montgomery used explicit formulas to study the pair correlation of the zeros of the zeta-function and their relationship to …


Effects Of Cigarette Butts On Coastal Waters: An Elemental Analysis Of Seawater From St. Simon’S Island, Katherine Adorati May 2016

Effects Of Cigarette Butts On Coastal Waters: An Elemental Analysis Of Seawater From St. Simon’S Island, Katherine Adorati

Honors Theses

Cigarette litter can have detrimental effects on the environment, specifically when taking into account that over 4.5 trillion cigarette butts are littered every year. Within seawater, trace elements present in cigarettes may leach into the ocean, having damaging effects on the marine ecosystem. The goal of this research was to investigate if elemental contaminants leached from cigarette litter are significant in samples of seawater collected near St. Simon’s Island at both high and low tides, surrounding a beach party during the Florida/Georgia football game which occurred on November 1, 2014. Samples were collected in the months prior to and during …


Alkaloids In E-Cigarettes: Their Effects On Cell Growth And Gene Regulation, Maxwell H. Marlowe May 2016

Alkaloids In E-Cigarettes: Their Effects On Cell Growth And Gene Regulation, Maxwell H. Marlowe

Honors Theses

E-cigarettes have become increasingly popular in the past decade. They are marketed as smoking cessation aids. These products have not been well regulated or researched with respect to health concerns and safety issues. A number of toxic compounds have been discovered in refill solutions, and the long-term effects of e-cigarette use are still largely unknown. Nicotine is one of the primary alkaloids within e-cigarette refill solutions. Nevertheless, other tobacco alkaloids are present including; cotinine, myosmine and anabasine, even though these compounds are not disclosed on the packaging. This study uses known amounts of tobacco alkaloids, in an in vitro culture …


Direct Band Gap Gallium Antimonide Phosphide (Gasbxp1-X) For Solar Fuels., Harry Benjamin Russell May 2016

Direct Band Gap Gallium Antimonide Phosphide (Gasbxp1-X) For Solar Fuels., Harry Benjamin Russell

Electronic Theses and Dissertations

Photoelectrochemical water splitting has been identified as a promising route for achieving sustainable energy future. However, semiconductor materials with the appropriate optical, electrical and electrochemical properties have yet to be discovered. In search of an appropriate semiconductor to fill this gap, GaSbP, a semiconductor never tested for PEC performance is proposed here and investigated. Density functional theory (DFT+U) techniques were utilized to predict band gap and band edge energetics for GaSbP alloys with low amount of antimony. The overall objective of this dissertation is to understand the suitability of GaSbxP1-x alloys for photoelectrochemical water splitting application. Specifically, …


Computation Of Least Angle Regression Coefficient Profiles And Lasso Estimates., Sandamala Hettigoda May 2016

Computation Of Least Angle Regression Coefficient Profiles And Lasso Estimates., Sandamala Hettigoda

Electronic Theses and Dissertations

Variable selection plays a significant role in statistics. There are many variable selection methods. Forward stagewise regression takes a different approach among those. In this thesis Least Angle Regression (LAR) is discussed in detail. This approach has similar principles as forward stagewise regression but does not suffer from its computational difficulties. By using a small artificial data set and the well-known Longley data set, the LAR algorithm is illustrated in detail and the coefficient profiles are obtained. Furthermore a penalized approach to variable reduction called the LASSO is discussed, and it is shown how to compute its coefficient profiles efficiently …


Viscous Dissipation And Heat Absorption Effect On Natural Convection Flow With Uniform Surface Temperature Along A Vertical Wavy Surface, Sujon Nath, Nazma Parveen May 2016

Viscous Dissipation And Heat Absorption Effect On Natural Convection Flow With Uniform Surface Temperature Along A Vertical Wavy Surface, Sujon Nath, Nazma Parveen

Applications and Applied Mathematics: An International Journal (AAM)

The effect of viscous dissipation and heat absorption on a steady two-dimensional natural convection laminar flow of viscous incompressible fluid with uniform surface temperature along a vertical wavy surface has been investigated. Using the appropriate variables; the basic equations are transformed to convenient form and then solved numerically employing very efficient method, namely Keller-Box method (KBM). Numerical results are presented by the shearing stress in terms of the local skin-friction coefficient; the rate of heat transfer in terms of local Nusselt number, streamline and isotherms, respectively for a wide range of the viscous dissipation parameter N and heat absorption parameter …


Prandtl Number Effect On Assisted Convective Heat Transfer Through A Solar Collector, Rehen Nasrin, Salma Parvin, M. A. Alim May 2016

Prandtl Number Effect On Assisted Convective Heat Transfer Through A Solar Collector, Rehen Nasrin, Salma Parvin, M. A. Alim

Applications and Applied Mathematics: An International Journal (AAM)

Numerical study of the influence of Prandtl number on forced convective heat transfer through a riser pipe of a flat plate solar collector is done. The working fluid is Al2O3/water nanofluid. By Finite Element Method the governing partial differential equations are solved. The effect of the Prandtl number on the temperature and velocity field has been depicted. Comprehensive average Nusselt number, average bulk temperature, mean velocity, mid-height temperature inside the pipe, mean output temperature and collector efficiency are presented for the governing parameter mentioned above. Nu increases by 16% with the variation of Pr from 4.6 to 6.6 using nanofluid. …


Opinion Formation About Childhood Immunization And Disease Spread On Networks, Shan Shan Zhao May 2016

Opinion Formation About Childhood Immunization And Disease Spread On Networks, Shan Shan Zhao

Theses and Dissertations

People are physically and socially connected with each other. Those connections between people represent two, probably overlapping, networks: biological networks, through which physical contacts occur, or social network, through which information diffuse. In my thesis research, I am trying to answer that question in the context of pediatric disease spread on the biological network between households as well as within them and its relationship with information sharing on the social network of households (parents in that case) via "Information Cascades." I mainly focus on the Erdos-Renyi network model. In particular, I use two different but overlapping Erdos-Renyi networks for the …


Modeling The Sps Feedback And Feedforward Systems For Improved Performance, Jake Hargrove May 2016

Modeling The Sps Feedback And Feedforward Systems For Improved Performance, Jake Hargrove

Physics

The Super Proton Synchrotron (SPS) is the last link in the chain of accelerators providing protons to the Large Hadron Collider (LHC). The SPS is currently the limiting factor on the maximum number of protons and thus collisions in the LHC. The SPS upgrade is under way to expand the discovery potential of the LHC. The accelerating system — Radio Frequency (RF) — is being improved. Models of the SPS RF feedback systems were developed. These models could assist with design choices, evaluating the upgraded system performance, and anticipate limitations and issues.


Research Update: Bud Bank Ecology For Understanding Perennial Grass Persistence, Lan Xu May 2016

Research Update: Bud Bank Ecology For Understanding Perennial Grass Persistence, Lan Xu

Natural Resource Management Faculty Publications

Grassland ecosystems often demonstrate very remarkable resiliency to severe natural and anthropogenic disturbances. Such resiliency following disturbances comes from either seed banks (germinable seeds in the soil) or bud banks (meristems or buds, such as bulbs, bulbils, and buds on rhizomes, corms, and tubers, that generate vegetative tissues). Although seeds are important for dispersal, initial colonization, and maintenance of genetic diversity; few grass seeds persist in the soil more than five years, plus seed production often is unreliable under grazing. Recent studies have demonstrated that >99% of aboveground stems in undisturbed tallgrass prairie were recruited from the bud bank while <1% were recruited from the seed bank. Even under grazed or disturbed sites in tallgrass prairie, belowground buds make a significantly larger contribution (80%) to plant recruitment than do seeds (20%).


Agroecosystem And Ecosystem Resiliency To Extreme Hydrometeorological And Climate Events, Katherine M. Werner May 2016

Agroecosystem And Ecosystem Resiliency To Extreme Hydrometeorological And Climate Events, Katherine M. Werner

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The purpose of this study was to understand how a large-scale representation of agroecosystems and ecosystems respond to extreme hydrometeorological and climate extreme events (EHCE) within the Platte River Basin. The ability for agroecosystems and ecosystems to adapt to a changing and variable climate is vital for global water, energy, and food security. Two model experiments were performed, the first with a time span from 2000 to 2013 in which a dynamic leaf area index (LAI) MODIS15A2 product was implemented. The second experiment ran from 1950 through 2013 used a climatological fixed seasonal cycle calculated as the average from the …


Stable Local Cohomology And Cosupport, Peder Thompson May 2016

Stable Local Cohomology And Cosupport, Peder Thompson

Department of Mathematics: Dissertations, Theses, and Student Research

This dissertation consists of two parts, both under the overarching theme of resolutions over a commutative Noetherian ring R. In particular, we use complete resolutions to study stable local cohomology and cotorsion-flat resolutions to investigate cosupport.

In Part I, we use complete (injective) resolutions to define a stable version of local cohomology. For a module having a complete injective resolution, we associate a stable local cohomology module; this gives a functor to the stable category of Gorenstein injective modules. We show that this functor behaves much like the usual local cohomology functor. When there is only one non-zero local cohomology …


Cohen–Macaulay Dimension For Coherent Rings, Rebecca Egg May 2016

Cohen–Macaulay Dimension For Coherent Rings, Rebecca Egg

Department of Mathematics: Dissertations, Theses, and Student Research

This dissertation presents a homological dimension notion of Cohen-Macaulay for non-Noetherian rings which reduces to the standard definition in the case that the ring is Noetherian, and is inspired by the homological notion of Cohen-Macaulay for local rings developed by Gerko. Under this notion, both coherent regular rings (as defined by Bertin) and coherent Gorenstein rings (as defined by Hummel and Marley) are Cohen-Macaulay.

This work is motivated by Glaz's question regarding whether a notion of Cohen-Macaulay exists for coherent rings which satisfies certain properties and agrees with the usual notion when the ring is Noetherian. Hamilton and Marley gave …


Functionalizing Β-Cyano Oligo(P-Phenylene Vinylene) Chromophores For Use In Mechanochromic Materials, Alexander J. Wink May 2016

Functionalizing Β-Cyano Oligo(P-Phenylene Vinylene) Chromophores For Use In Mechanochromic Materials, Alexander J. Wink

Honors Theses

Mechanochromic materials are materials that change color upon mechanical deformation. This concept can be applied in areas of quality control, since the knowledge of damaged parts will easily be detected due to a color change in the material that has undergone deformation. Typically these types of materials are enabled by employing functional small molecules. Often, these are conjugated organic molecules or chromophores, which fluoresce different colors determined by the stimulus (or lack thereof) acting upon the material. In this work, we explore a new avenue to elicit color changes in polymeric materials based on the process of restriction of intramolecular …


Curing Of Polymer Thermosets Via Click Reactions, Mark Richard Brei May 2016

Curing Of Polymer Thermosets Via Click Reactions, Mark Richard Brei

Dissertations

In the first project, an azide functional resin and tetra propargyl aromatic diamines were fabricated for use as a composite matrix. These systems take already established epoxy/amine matrices and functionalize them with click moieties. This allows lower temperatures to be used in the production of a thermoset part. These new systems yield many better mechanical properties than their epoxy/amine derivatives, but their Tgs are low in comparison.

The second project investigates the characterization of a linear system based off of the above azide functional resin and a difunctional alkyne. Through selectively choosing catalyst the linear system can show …


Synthesis And Characterization Of "Click Inspired" Thiol-Ene-Fullerene Nanocomposites, Amber Danielle Windham May 2016

Synthesis And Characterization Of "Click Inspired" Thiol-Ene-Fullerene Nanocomposites, Amber Danielle Windham

Dissertations

This work explores the covalent incorporation of C60 and Sc3N@C80 fullerenes into thiol-ene networks by a facile, one-pot photochemical reaction with multifunctional thiol and alkene monomers. Synthesis of disulfide bonds within the tri-functional thiol monomer served to photochemically initiate the reaction when cleaved. This was followed by thermal curing of the pre-polymer for preparation of fullerene-containing thiol-ene films. Films were characterized by standard techniques including infrared spectroscopy, gel percent, and thermogravimetric analysis. The role of C60 and Sc3N@C80 as suitable alkenes for free-radical reaction with multifunctional thiols was investigated by preparing a …