Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2015

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 11461 - 11490 of 12617

Full-Text Articles in Physical Sciences and Mathematics

The Toric Approach To F-Theory Model Building, Herbie L. Smith Jan 2015

The Toric Approach To F-Theory Model Building, Herbie L. Smith

Honors Theses and Capstones

We describe the theoretical motivation for F-theory as a non-perturbative generalization of string theory. The four complex-dimensional compactification spaces of F-theory, called elliptically-fibered Calabi-Yau manifolds, consist of the six compact dimensions of string theory, plus a two-dimensional fiber that describes the string coupling field as a function of position on the string theory manifold. The methods of toric geometry are developed and applied to construct examples of elliptically-fibered Calabi-Yau manifolds. We analyze in detail models in which the fiber is free of singularities as a test bed for a more general analysis.

Go to article

Improved Full-Newton-Step Infeasible Interior-Point Method For Linear Complementarity Problems, Mustafa Ozen Jan 2015

Improved Full-Newton-Step Infeasible Interior-Point Method For Linear Complementarity Problems, Mustafa Ozen

Electronic Theses and Dissertations

In this thesis, we present an improved version of Infeasible Interior-Point Method (IIPM) for monotone Linear Complementarity Problem (LCP). One of the most important advantages of this version in compare to old version is that it only requires feasibility steps. In the earlier version, each iteration consisted of one feasibility step and some centering steps (at most three in practice). The improved version guarantees that after one feasibility step, the new iterated point is feasible and close enough to central path. Thus, the centering steps are eliminated. This improvement is based on the Lemma(Roos, 2015). Thanks to this lemma, proximity …

Go to article

Combinatorial Game Theory: An Introduction To Tree Topplers, John S. Ryals Jr. Jan 2015

Combinatorial Game Theory: An Introduction To Tree Topplers, John S. Ryals Jr.

Electronic Theses and Dissertations

The purpose of this thesis is to introduce a new game, Tree Topplers, into the field of Combinatorial Game Theory. Before covering the actual material, a brief background of Combinatorial Game Theory is presented, including how to assign advantage values to combinatorial games, as well as information on another, related game known as Domineering. Please note that this document contains color images so please keep that in mind when printing.

Go to article

Total Synthesis Of Biologically Active Natural And Unnatural Products, Julia Heimberger Jan 2015

Total Synthesis Of Biologically Active Natural And Unnatural Products, Julia Heimberger

Electronic Theses and Dissertations

Herbarin A and B were isolated from the fungal strains of Cladosporium herbarum found in marine sponges Aplysina aerophoba and Callyspongia aerizusa. Total synthesis of Herbarin A and B was achieved by carrying out a multi-step synthesis approach, and the antioxidant properties were evaluated using FRAP assay. Toxicity of these compounds was determined using a zebrafish embryo model. Furthermore, synthesis of C-6 alkyl-azaarene derivatives of nucleosides by Csp3-H bond functionalization were investigated. Effective incorporation of 2-methylazaarene moiety at the C-6 position of the protected inosine nucleoside provided a new class of compounds with anticipated enhanced biological activity.

Go to article

Characterizations Of Gamma Distribution Via Sub-Independent Random Variables, Gholamhossein Hamedani Jan 2015

Characterizations Of Gamma Distribution Via Sub-Independent Random Variables, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

The concept of sub-independence is based on the convolution of the distributions of the random variables. It is much weaker than that of independence, but is shown to be sufficient to yield the conclusions of important theorems and results in probability and statistics. It also provides a measure of dissociation between two random variables which is much stronger than uncorrelatedness. Inspired by the excellent work of Jin and Lee (2014), we present certain characterizations of gamma distribution based on the concept of sub-independence.

Go to article

Preparing Secondary Mathematics Teachers: Focus On Modeling In Algebra, Hyunyi Jung, Alexia Mintos, Jill Newton Jan 2015

Preparing Secondary Mathematics Teachers: Focus On Modeling In Algebra, Hyunyi Jung, Alexia Mintos, Jill Newton

Mathematics, Statistics and Computer Science Faculty Research and Publications

This study addressed the opportunities to learn (OTL) modeling in algebra provided to secondary mathematics pre-service teachers (PSTs). To investigate these OTL, we interviewed five instructors of required mathematics and mathematics education courses that had the potential to include opportunities for PSTs to learn algebra at three universities. We also interviewed a group of three to four PSTs at each of the universities. We coded the interview transcripts using an analytic framework developed based on related literature and policy documents. We report the similarities and differences in perspectives among instructors and PSTs related to modeling at each university, along with …

Go to article

Combinatorially Interpreting Generalized Stirling Numbers, John Engbers, David Galvin, Justin Hilyard Jan 2015

Combinatorially Interpreting Generalized Stirling Numbers, John Engbers, David Galvin, Justin Hilyard

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.

Go to article

Exponentially Increasing Incidences Of Cutaneous Malignant Melanoma In Europe Correlate With Low Personal Annual Uv Doses And Suggests 2 Major Risk Factors, Stephen Merrill, Samira Ashrafi, Madhan Subramanian, Dianne E. Godar Jan 2015

Exponentially Increasing Incidences Of Cutaneous Malignant Melanoma In Europe Correlate With Low Personal Annual Uv Doses And Suggests 2 Major Risk Factors, Stephen Merrill, Samira Ashrafi, Madhan Subramanian, Dianne E. Godar

Mathematics, Statistics and Computer Science Faculty Research and Publications

For several decades the incidence of cutaneous malignant melanoma (CMM) steadily increased in fair-skinned, indoor-working people around the world. Scientists think poor tanning ability resulting in sunburns initiate CMM, but they do not understand why the incidence continues to increase despite the increased use of sunscreens and formulations offering more protection. This paradox, along with lower incidences of CMM in outdoor workers, although they have significantly higher annual UV doses than indoor workers have, perplexes scientists. We found a temporal exponential increase in the CMM incidence indicating second-order reaction kinetics revealing the existence of 2 major risk factors. From epidemiology …

Go to article

Relativistic Electron Avalanches As A Thunderstorm Discharge Competing With Lightning, Nicole A. Kelley, David M. Smith, Joseph R. Dwyer, Michael Splitt, Steven Lazarus, Forest Martinez-Mckinney, Bryna Hazelton, Brian Grefenstette, Alexander Lowell, Hamid K. Rassoul Jan 2015

Relativistic Electron Avalanches As A Thunderstorm Discharge Competing With Lightning, Nicole A. Kelley, David M. Smith, Joseph R. Dwyer, Michael Splitt, Steven Lazarus, Forest Martinez-Mckinney, Bryna Hazelton, Brian Grefenstette, Alexander Lowell, Hamid K. Rassoul

Ocean Engineering and Marine Sciences Faculty Publications

Gamma-ray ‘glows’ are long duration (seconds to tens of minutes) X-ray and gamma-ray emission coming from thunderclouds. Measurements suggest the presence of relativistic runaway electron avalanches (RREA), the same process underlying terrestrial gamma-ray flashes. Here we demonstrate that glows are relatively a common phenomena near the tops of thunderstorms, when compared with events such as terrestrial gamma-ray flashes. Examining the strongest glow measured by the airborne detector for energetic emissions, we show that this glow is measured near the end of a downward RREA, consistent with occurring between the upper positive charge layer and the negative screening layer above it. …

Go to article

Bayesian Inference Of The Weibull-Pareto Distribution, James Dow Jan 2015

Bayesian Inference Of The Weibull-Pareto Distribution, James Dow

Electronic Theses and Dissertations

The Weibull distribution has many applications in various topics. Some of these topics include survival analysis, reliability engineering, general insurance, electrical engineering, and industrial engineering. The Weibull distribution was further extended by the Weibull-Pareto distribution. A desirable property this distribution has is its shape can skew being able to better model left or right skewed data. Examples of skewed data include human longevity and actuarial data. In this work a hierarchical Bayesian model was developed using the Weibull-Pareto distribution.

Go to article

Characterizations Of Nwp, Etgr And Twl Distributions, Gholamhossein Hamedani Jan 2015

Characterizations Of Nwp, Etgr And Twl Distributions, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

Utilizing a simple relationship between two truncated moments as well as certain functions of the 1st and of the nth order statistics, we characterize three extended classes of distributions proposed in (2015).

Go to article

Kumaraswamy-Half-Cauchy Distribution: Characterizations And Related Results, Gholamhossein Hamedani, I. Ghosh Jan 2015

Kumaraswamy-Half-Cauchy Distribution: Characterizations And Related Results, Gholamhossein Hamedani, I. Ghosh

Mathematics, Statistics and Computer Science Faculty Research and Publications

We present various characterizations of a recently introduced distribution (Ghosh 2014), called Kumaraswamy- Half- Cauchy distribution based on: (i) a simple relation between two truncated moments; (ii) truncated moment of certain function of the 1st order statistic; (iii) truncated moment of certain function of the random variable; (iv) hazard function; (v) distribution of the 1st order statistic; (vi) via record values. We also provide some remarks on bivariate Gumbel copula distribution whose marginal distributions are Kumaraswamy- Half-Cauchy distributions.

Go to article

Characterizations Of Distributions Via Conditional Expectation Of Generalized Order Statistics, M. Ahsanullah, Gholamhossein Hamedani, Mehdi Maadooliat Jan 2015

Characterizations Of Distributions Via Conditional Expectation Of Generalized Order Statistics, M. Ahsanullah, Gholamhossein Hamedani, Mehdi Maadooliat

Mathematics, Statistics and Computer Science Faculty Research and Publications

Characterizations of probability distributions by different regression conditions on generalized order statistics has attracted the attention of many researchers. We present here, characterizations of certain continuous distributions based on the conditional expectation of generalized order statistics.

Go to article

Pressure-Temperature-Time Constraints For Exhumation Of Ultrahigh-Pressure Metamorphic Rocks, North Qaidam Terrane, Western China, Brittany Kristine Fagin Jan 2015

Pressure-Temperature-Time Constraints For Exhumation Of Ultrahigh-Pressure Metamorphic Rocks, North Qaidam Terrane, Western China, Brittany Kristine Fagin

All Master's Theses

Ultrahigh-pressure rocks of a Paleozoic continental suture zone are exposed in the southeastern North Qaidam terrane (Dulan region). Garnetite sample D119 contains minor Czo+Qtz+Chl+Ttn; rutile inclusions in titanite suggest that titanite replaced rutile during decompression. Pressure-temperature estimates of sample D119 are 16.1-18.4 kbar and 485-520 °C. Sample D130B is a mafic band in calc-silicate gneiss, with garnet porphyroblasts in a fine-grained Hbl-Cpx-Pl-Qtz symplectite that is interpreted as former omphacite. D130B symplectite pressure-temperature estimates are 7.7-9.4 kbar and 623-708 °C. Titanite U-Pb ages of 419.7±3.1 Ma and 415.9±4.2 Ma are interpreted to date retrogression of D119 and D130B, respectively. Average exhumation …

Go to article

Dynamic Phases, Pinning, And Pattern Formation For Driven Dislocation Assemblies, Caizhi Zhou, Charles Reichhardt, Cynthia Olson Reichhardt, Irene J. Beyerlein Jan 2015

Dynamic Phases, Pinning, And Pattern Formation For Driven Dislocation Assemblies, Caizhi Zhou, Charles Reichhardt, Cynthia Olson Reichhardt, Irene J. Beyerlein

Materials Science and Engineering Faculty Research & Creative Works

We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation and dynamics …

Go to article

Pedagogical Possibilities For The 2048 Puzzle Game, Todd W. Neller Jan 2015

Pedagogical Possibilities For The 2048 Puzzle Game, Todd W. Neller

Computer Science Faculty Publications

In this paper, we describe an engaging puzzle game called 2048 and outline a variety of exercises that can leverage the game’s popularity to engage student interest, reinforce core CS concepts, and excite student curiosity towards undergraduate research. Exercises range in difficulty from CS1-level exercises suitable for exercising and assessing 1D and 2D array skills to empirical undergraduate research in Monte Carlo Tree Search methods and skilled heuristic evaluation design.

Go to article

Heterometallic Titanium–Gold Complexes Inhibit Renal Cancer Cells In Vitro And In Vivo, Jacob Fernandez-Gallardo, Benelita T. Elie, Tanmoy Sadhukha, Swayam Prabha, Mercedes Sanau, Susan A. Rotenberg, Joe W. Ramos, Maria Contel Jan 2015

Heterometallic Titanium–Gold Complexes Inhibit Renal Cancer Cells In Vitro And In Vivo, Jacob Fernandez-Gallardo, Benelita T. Elie, Tanmoy Sadhukha, Swayam Prabha, Mercedes Sanau, Susan A. Rotenberg, Joe W. Ramos, Maria Contel

Publications and Research

Following recent work on heterometallic titanocene–gold complexes as potential chemotherapeutics for renal cancer, we report here on the synthesis, characterization and stability studies of new titanocene complexes containing a methyl group and a carboxylate ligand (mba ¼ S–C6H4–COO) bound to gold(I)-phosphane fragments through a thiolate group [(h-C5H5)2TiMe(m-mba)Au(PR3)]. The compounds are more stable in physiological media than those previously reported and are highly cytotoxic against human cancer renal cell lines. We describe here preliminary mechanistic data involving studies on the interaction of selected compounds with plasmid (pBR322) DNA used as a model nucleic acid, and with selected protein kinases from a …

Go to article

Expression And Characterization Of Mouse Notch1 Abruptex Egf Repeats In E. Coli, Amid Paudyal Jan 2015

Expression And Characterization Of Mouse Notch1 Abruptex Egf Repeats In E. Coli, Amid Paudyal

LSU Master's Theses

Notch1 is a transmembrane protein involved in cell signaling, which is found to be linked to various genetic and neurodegenerative diseases. The extracellular domain of the Notch1 protein consists of 36 tandem epidermal growth factor-like (EGF) repeats, which are directly involved in ligand binding and are heavily glycosylated. EGF 24-29 repeats lie in the Abruptex region of the Notch1 protein, and regulate the ligand binding activity through structural changes. The role of glycosylation in ligand binding events and the overall structure of the Abruptex region are not known. Also, the role of calcium binding in Notch activation or inhibition is …

Go to article

Rapid Middle To Late Miocene Slip Along The Zanskar Normal Fault, Greater Himalayan Range, Nw, India: Constraints From Low-Temperature Thermochronometry, Brett L. Shurtleff Jan 2015

Rapid Middle To Late Miocene Slip Along The Zanskar Normal Fault, Greater Himalayan Range, Nw, India: Constraints From Low-Temperature Thermochronometry, Brett L. Shurtleff

All Master's Theses

The Zanskar normal fault (ZF) is a NW-striking, moderately NE-dipping, normal fault that bounds the northern flank of the Greater Himalaya Range, NW India. The ZF is the far west continuation of the South Tibetan Detachment System (STDS), a major arc-parallel normal sense shear zone that spans the length of the Himalayan orogen. Detailed new zircon and apatite (U-Th)/He (ZHe and AHe) and apatite fission-track (AFT) thermochronometric data from high-grade (amphibolite-migmatite) Greater Himalayan Sequence (GHS) metamorphic rocks, exposed in the footwall immediately adjacent to the ZF, provide constraints on the middle Miocene to present exhumation history of the footwall. The …

Go to article

Spectroscopic Studies On The Interaction Of Cetylpyridinium Bromide Monohydrate And Bromothymol Blue With Polymerized Silica, James Siegenthaler Jan 2015

Spectroscopic Studies On The Interaction Of Cetylpyridinium Bromide Monohydrate And Bromothymol Blue With Polymerized Silica, James Siegenthaler

All Master's Theses

The design and implementation of a controlled macromolecular chemical transport system could greatly advance switchable chemical reactions and be applicable for targeted drug delivery, intelligent inks, and nanotechnology. To better understand the mechanisms of function for a switchable macromolecular transport system, preliminary work has been completed that studies the transport of bromothymol blue (BB) facilitated by cetylpyridinium bromide monohydrate (CPBM) to a silica surface that has been modified with Poly(styrene-co-maleic anhydride), a pH switchable polymer. Ultraviolet spectroscopic trials were conducted measuring the absorbance of BB and CPBM at 3 pH levels and 3 different surface reactivity levels of …

Go to article

River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2015, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Lucy Sonnenberg, Gerry Pinto, Nisse Goldberg, Anthony Ouellette, Gretchen Bielmyer-Fraser, Stuart J. Chalk, Peter Bacopoulos, Brian P. Zoellner Jan 2015

River Report. State Of The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2015, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University, Lucy Sonnenberg, Gerry Pinto, Nisse Goldberg, Anthony Ouellette, Gretchen Bielmyer-Fraser, Stuart J. Chalk, Peter Bacopoulos, Brian P. Zoellner

State of the River Report

No abstract provided.

Go to article

The Graph Theory Origin Story (Abstract), Daniel Roberts Jan 2015

The Graph Theory Origin Story (Abstract), Daniel Roberts

Undergraduate Mathematics Day: Programs, Lectures, Promotional Materials

Many research questions in pure mathematics arise from considerations of real world problems. Part of the job of a mathematician is to ask this type of question.

Go to article

2015 Undergraduate Mathematics Day Poster, University Of Dayton. Department Of Mathematics Jan 2015

2015 Undergraduate Mathematics Day Poster, University Of Dayton. Department Of Mathematics

Undergraduate Mathematics Day: Programs, Lectures, Promotional Materials

No abstract provided.

Go to article

2015 Program And Abstracts, University Of Dayton. Department Of Mathematics Jan 2015

2015 Program And Abstracts, University Of Dayton. Department Of Mathematics

Undergraduate Mathematics Day: Programs, Lectures, Promotional Materials

No abstract provided.

Go to article

Dispersant Effects On Zinc Dialkyldithiophosphate (Zddp) Tribofilm Structure And Composition, Makaye Tabibi Jan 2015

Dispersant Effects On Zinc Dialkyldithiophosphate (Zddp) Tribofilm Structure And Composition, Makaye Tabibi

Theses and Dissertations

For decades, global regulations and government mandates have driven technological developments to improve vehicle fuel economy. Tribological components found in all automotive engines contain metal-on-metal contact zones that may result in increased friction and wear, reducing overall engine efficiency. Lubricant additives such as antiwear and friction modifying components are added to motor oils to prevent some of the damages that may occur at contact zones and improve friction. The effects of other additive components, such as dispersants, that are prevalent in a lubricant additive package on the anti-wear layer remain relatively unknown. Polyisobutenyl Succinimide (PIBSI) dispersants were evaluated for their …

Go to article

Surface Photovoltage Transients For P-Type Algan, Karen L. Phumisithikul Jan 2015

Surface Photovoltage Transients For P-Type Algan, Karen L. Phumisithikul

Theses and Dissertations

There is an understanding of surface photovoltage (SPV) behavior for GaN, yet little is known about the SPV behavior for AlGaN. In this work, a Kelvin probe was used to measure the SPV for p-type AlGaN. Very slow SPV transients were found in AlGaN, which could not be explained with a simple thermionic model. A possible explanation of this behavior is the segregation of impurities to the surface, which causes significant reduction of the depletion region width (down to 2 nm), with carrier tunneling and hopping becoming the dominant mechanisms responsible for the SPV transients. To verify this assumption, …

Go to article

Measurement Of Particulate Transition Metals And Atmospheric Processing Of Iron, Benton T. Cartledge Jan 2015

Measurement Of Particulate Transition Metals And Atmospheric Processing Of Iron, Benton T. Cartledge

Electronic Theses and Dissertations

The work presented herein details the measurement of particle-bound metals in environmental samples with specific interests in iron (Fe) in atmospheric particulate matter. Metals were measured in ambient PM2.5 to study the effects and contributions of a light rail system on the concentrations of metals in atmospheric particles. Particulate matter samples were collected on board trains, near the tracks, and at an urban background location in Denver, CO. Metals were found to be enriched in particles collected on board the trains more so than at the other locations. Fe speciation was also measured in the soluble fraction of the …

Go to article

Identification Of High Energy Cosmic Ray Electrons Using Advanced Techniques In Calet And Fermi Lat, Aaron James Worley Jan 2015

Identification Of High Energy Cosmic Ray Electrons Using Advanced Techniques In Calet And Fermi Lat, Aaron James Worley

Electronic Theses and Dissertations

Measurements of the cosmic ray electron spectrum have received much attention over the last decade as anomalies in both electron and positron observations have been detected independently by several experiments. The profound possible implications in the fields of high energy astrophysics and particle physics have allowed for many interpretations on the origin of these inconsistencies in the spectra. This research focuses on two space-borne cosmic radiation experiments at different stages in their mission lifetimes: the Calorimetric Electron Telescope (CALET) and the Fermi Large Area Telescope (LAT). We explore the proton-electron discriminating capabilities of the CALET instrument through Monte Carlo simulations. …

Go to article

Climate Driven Changes To Malaria Transmission Patterns In Ethiopian Highlands, Amir Said Siraj Jan 2015

Climate Driven Changes To Malaria Transmission Patterns In Ethiopian Highlands, Amir Said Siraj

Electronic Theses and Dissertations

In the highlands of East Africa, the most populated regions in Africa, temperature is assumed to be intimately connected to the patterns of malaria both in time and space. A large section of the Ethiopian population in this region has historically been shielded from the disease mainly due to the altitudes in the highland regions that have remained free of the disease. However, the region has also seen a large part of its population being affected by malaria in epidemic outbreaks that seem to follow climatic anomalies, especially those of inter-annual increases in temperature. This project examines the inter-annual variability …

Go to article

Algebraic And Numerical Exploration Of Free Energies For Materials With Memory, John Murrough Golden, Giovambattista Amendola, Mauro Fabrizio Jan 2015

Algebraic And Numerical Exploration Of Free Energies For Materials With Memory, John Murrough Golden, Giovambattista Amendola, Mauro Fabrizio

Articles

Abstract. We study the forms of a range of free energy functionals for materials with memory for two types of strain history, namely sinusoidal and ex- ponential behaviours. The work deals with discrete spectrum materials, which are those with relaxation functions given by sums of decaying exponentials.

Go to article

First Prev Next Last