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

Physical Sciences and Mathematics Commons™

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

2013

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 361 - 390 of 8928

Full-Text Articles in Physical Sciences and Mathematics

Magic Squares Of Squares Of Order 4 Over Certain Finite Fields, Drew O’Neill Dec 2013

Magic Squares Of Squares Of Order 4 Over Certain Finite Fields, Drew O’Neill

Theses, Dissertations and Culminating Projects

A magic square of order n over a commutative ring R is an n x n matrix such that all the rows, columns, and the two diagonals add up to a fixed sum, which is called the magic sum. If all of the numbers in a magic square are perfect squares in R, it is called a magic square of squares. The rings under consideration in this thesis are either Z or Zp where p is a prime. In this thesis I present methods of constructing magic squares of squares of order 4 from selected ones of order 3. A …


Molecular Dynamics Simulations Using Advanced Sampling And Polarizable Force Fields, Tugba Kucukkal Dec 2013

Molecular Dynamics Simulations Using Advanced Sampling And Polarizable Force Fields, Tugba Kucukkal

All Dissertations

Molecular dynamics (MD) simulations were carried out for aqueous dipeptides, water over self-assembled monolayer (SAM) surfaces, and the nicotinic acetylcholine receptor (nAChR) ion channel. The main goal is to use advanced methods to increase the accuracy of molecular dynamics simulations while seeking solutions to problems relevant to chemistry, biophysics and materials science. In addition, activation energies of several cyclodimerization reactions were studied quantum mechanically. The simulations of the aqueous dipeptides and SAM surfaces involve modeling and detailed analysis of interfacial water, which is of interest to a range of fields from biology to materials science. For example, water has a …


Phosphate Esters, Thiophosphate Esters And Metal Thiophosphates As Lubricant Additives, David W. Johnson, John E. Hils Dec 2013

Phosphate Esters, Thiophosphate Esters And Metal Thiophosphates As Lubricant Additives, David W. Johnson, John E. Hils

Chemistry Faculty Publications

Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. While their use has been extensive, a detailed knowledge of how they work has been a much more recent development. In this paper, the use of phosphate esters and thiophosphate esters as anti-wear or extreme pressure additives is reviewed with an emphasis on their mechanism of action. The review includes the use of alkyl phosphates, triaryl phosphates and metal containing thiophosphate esters. The mechanisms of these materials interacting with a range of iron and steel based bearing material are examined.


In Perfect Xen, A Performance Study Of The Emerging Xen Scheduler, Ryan Hnarakis Dec 2013

In Perfect Xen, A Performance Study Of The Emerging Xen Scheduler, Ryan Hnarakis

Master's Theses

Fifty percent of Fortune 500 companies trust Xen, an open-source bare-metal hypervisor, to virtualize their websites and mission critical services in the cloud. Providing superior fault tolerance, scalability, and migration, virtualization allows these companies to run several isolated operating systems simultaneously on the same physical server. These isolated operating systems, called virtual machines, require a virtual traffic guard to cooperate with one another. This guard known as the Credit2 scheduler along with the newest Xen hypervisor was recently developed to supersede the older schedulers. Since wasted CPU cycles can be costly, the Credit2 prototype must undergo significant performance validation before …


Time Variation Of The Broad Hβ And Hα Emission Lines In Active Galactic Nuclei, Bryan R. Scott Dec 2013

Time Variation Of The Broad Hβ And Hα Emission Lines In Active Galactic Nuclei, Bryan R. Scott

Physics

High-quality Keck/LRIS long-slit spectra for a sample of 97 active galaxies selected from the Sloan Digital Sky Survey (redshift between 0.02 & 0.1; Black Hole Mass approximately 107 Solar Masses) were obtained between January 2009 and March 2010 in order to study the black hole (BH) mass scaling relation in the local universe. Typically, the width of the broad Hβ emission line is used to measure the mass of the black hole (MBH). However, signs of variability in the emission line profile are seen for eight objects: While broad Hβ emission lines had previously been observed in spectra from …


The Imperative Of Conserving California's Foothill Oak Woodlands, Lauren Phillips Dec 2013

The Imperative Of Conserving California's Foothill Oak Woodlands, Lauren Phillips

Social Sciences

No abstract provided.


Design And Development Of A Low-Cost Handheld Picoammeter, Malcolm Stagg Dec 2013

Design And Development Of A Low-Cost Handheld Picoammeter, Malcolm Stagg

Honors Capstones

No abstract provided.


Distribution Of Seaside Sparrows (Ammodramus Maritimus) During The Breeding And Nonbreeding Seasons, Bonnie J. Slaton Dec 2013

Distribution Of Seaside Sparrows (Ammodramus Maritimus) During The Breeding And Nonbreeding Seasons, Bonnie J. Slaton

Honors Capstones

No abstract provided.


Consolidation And Suspension Of Mud From Lake Lery And Relevance To Wetland Restoration In Louisiana, Edward L. Lo Dec 2013

Consolidation And Suspension Of Mud From Lake Lery And Relevance To Wetland Restoration In Louisiana, Edward L. Lo

Honors Capstones

No abstract provided.


On The Exact Distribution Of The Maximum Of The Exponential Of The Generalized Normal-Inverse Gaussian Process With Respect To A Martingale Measure, Roman V Ivanov Dec 2013

On The Exact Distribution Of The Maximum Of The Exponential Of The Generalized Normal-Inverse Gaussian Process With Respect To A Martingale Measure, Roman V Ivanov

Communications on Stochastic Analysis

No abstract provided.


Local Time Of A Multifractional Gaussian Process, Aissa Sghir Dec 2013

Local Time Of A Multifractional Gaussian Process, Aissa Sghir

Communications on Stochastic Analysis

No abstract provided.


The Solid State Simulation Of The Structure And Vibrational Modes Of Organic, Hybrid Organometallic And Inorganic Species Using The Crystal09 Code., Steven Pellizzeri Dec 2013

The Solid State Simulation Of The Structure And Vibrational Modes Of Organic, Hybrid Organometallic And Inorganic Species Using The Crystal09 Code., Steven Pellizzeri

Dissertations - ALL

An investigation of the structural and vibrational information of organic, hybrid organometallic and inorganic species was conducted using solid-state density functional theory (DFT). In this work the solid state DFT modeling was accomplished using the CRYSTAL09 code to simulate the geometries and vibrational modes of a variety of systems. These studies included: (1) the investigation of three polymorphs of vanadium phosphate, (2) three studies involving the use of 5-(4-pyridyl)tetrazole, and lastly (3) the crystal structure and simulation of α,α,α’,α’-tetrabromo-p-xylene. The studies involving 5-(4-pyridyl)tetrazole are comprised of (a) the comparison of a new polymorph to previously published crystallographic information of the …


Interpreting Near Infrared Hydrogen Line Ratios In T Tauri Stars, Suzan Edwards Dec 2013

Interpreting Near Infrared Hydrogen Line Ratios In T Tauri Stars, Suzan Edwards

Astronomy: Faculty Publications

In accreting young stars, one of the prominent spectral features in the near-infrared is the Paschen and Brackett series in emission. We examine hydrogen line ratios for 16 classical T Tauri stars from SpeX spectra and assess the trends with veiling and accretion. The observed line ratios are compared with two theoretical models for line formation: (1) Baker & Menzel’s Case B for radiative ionization and recombination and (2) a set of local line excitation calculations designed to replicate the conditions in T Tauri winds and magnetic accretion columns (KF). While the comparison between Case B and observed line ratios …


Mass Bays Resource Inventory: Summary And Findings From The Review Of Plans And Assessments, Urban Harbors Institute, University Of Massachusetts Boston Dec 2013

Mass Bays Resource Inventory: Summary And Findings From The Review Of Plans And Assessments, Urban Harbors Institute, University Of Massachusetts Boston

Urban Harbors Institute Publications

The Massachusetts Bays Program (MBP) contracted with the Urban Harbors Institute (UHI) of the University of Massachusetts Boston to conduct a review of papers, presentations, reports, and other relevant material produced from 1996 (the last CCMP) to present, that might inform the MBP’s update of their Comprehensive Conservation and Management Plan (CCMP). The review focused on five topics identified as priority topics by the MBP: water quality, invasive species, climate change/vulnerability, continuity of estuarine habitat, and estuarine habitat protection in the geographic region of the Mass Bays Program, particularly the 47 nearshore estuaries and embayments identified in the 2012 MBP …


Educating The Masses: Human Attitudes Affecting Reef Health, Ashley Wiehl Dec 2013

Educating The Masses: Human Attitudes Affecting Reef Health, Ashley Wiehl

HCNSO Student Theses and Dissertations

About two thirds of the world’s population lives within 60 km of a coastline, however many members of the public do not recognize the importance of the nearby coral reef ecosystems. Although reef degradation is currently occurring at alarming rates, there is hope for the future of coral reef health. It is proven that humans have a large effect on the current health of coral reefs. This thesis aims to determine how marine scientists and educators can best influence the general public to affect behaviors to improve reef health. To do this involves taking analyzing the many effects of human …


Assessing The Biodiversity And Susceptibility Of Trees In Maxwell Park To Future Invasive Tree Pest Outbreaks, Genevieve Alexander '14 Dec 2013

Assessing The Biodiversity And Susceptibility Of Trees In Maxwell Park To Future Invasive Tree Pest Outbreaks, Genevieve Alexander '14

Outstanding Senior Seminar Papers

The purpose of this project was to assess tree susceptibility to invasive tree pest outbreaks in a Central-Illinois urban park. Tree biodiversity in Maxwell Park, located in the Town of Normal, Illinois, was evaluated assuming that the greater the tree biodiversity in a park, the more resilient the park would be to future invasive tree pest outbreaks. The Town of Normal Parks and Recreation Department served as the community partner for this project. By determining Maxwell Park’s current level of biodiversity, proposed new trees for future replacement plantings could be identified to help increase biodiversity and decrease the potential for …


Assessing The Indoor Tanning Behaviors And Risk Of Skin Cancer Among Illinois Wesleyan University Students, Ellen Cornelius '14 Dec 2013

Assessing The Indoor Tanning Behaviors And Risk Of Skin Cancer Among Illinois Wesleyan University Students, Ellen Cornelius '14

Outstanding Senior Seminar Papers

The purpose of this research is to assess the indoor tanning behaviors of students at Illinois Wesleyan University (IWU) in Bloomington, Illinois and formulate strategies to reduce students’ risk of skin cancer. Skin cancer is widespread, and is the second most common cancer among people aged 15-24 years. There is strong evidence to support that many skin cancer cases seen today could have been avoided if the individual had never used an indoor tanning device. Research suggests the use of indoor tanning devices is popular among college-aged females in the US, thus persuading this demographic to reduce their indoor tanning …


Application Of Linear Sequences To Cryptography, Amanda C. Yeates Dec 2013

Application Of Linear Sequences To Cryptography, Amanda C. Yeates

Honors Theses

Cryptography is the study of a centuries–old technique of secretly transferring information between parties. Linear recurrences were the chosen method of encryption and decryption in the thesis. The Fibonacci sequence, with its Zeckendorf representation, allows for the flexibility of encoding any number desired based on a particular encoding technique used in the film Sherlock Holmes: A Game of Shadows. The main goal is to find other linear recurrences that possess characteristics similar to the Fibonacci sequence to use as suitable substitutes for encoding. Different sequences were analyzed based on a number of criteria. In order for a sequence to be …


Decision Trees To Model The Impact Of Disruption And Recovery In Supply Chain Networks, Loganathan Ponnanbalam, L. Wenbin, Xiuju Fu, Xiaofeng Yin, Zhaoxia Wang, Rick S. M. Goh Dec 2013

Decision Trees To Model The Impact Of Disruption And Recovery In Supply Chain Networks, Loganathan Ponnanbalam, L. Wenbin, Xiuju Fu, Xiaofeng Yin, Zhaoxia Wang, Rick S. M. Goh

Research Collection School Of Computing and Information Systems

Increase in the frequency of disruptions in the recent times and their impact have increased the attention in supply chain disruption management research. The objective of this paper is to understand as to how a disruption might affect the supply chain network - depending upon the network structure, the node that is disrupted, the disruption in production capacity of the disrupted node and the period of the disruption - via decision trees. To this end, we first developed a 5-tier agent-based supply chain model and then simulated it for various what-if disruptive scenarios for 3 different network structures (80 trials …


Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw Dec 2013

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles …


Clustering And Classification Of Multi-Domain Proteins, Neethu Shah Dec 2013

Clustering And Classification Of Multi-Domain Proteins, Neethu Shah

School of Computing: Dissertations, Theses, and Student Research

Rapid development of next-generation sequencing technology has led to an unprecedented growth in protein sequence data repositories over the last decade. Majority of these proteins lack structural and functional characterization. This necessitates design and development of fast, efficient, and sensitive computational tools and algorithms that can classify these proteins into functionally coherent groups.

Domains are fundamental units of protein structure and function. Multi-domain proteins are extremely complex as opposed to proteins that have single or no domains. They exhibit network-like complex evolutionary events such as domain shuffling, domain loss, and domain gain. These events therefore, cannot be represented in the …


Biome Q10 And Dryness, Chuixiang Yi, Daniel Ricciuto, George Hendrey Dec 2013

Biome Q10 And Dryness, Chuixiang Yi, Daniel Ricciuto, George Hendrey

Publications and Research

Temperature sensitivity of soil respiration (Q10) is a critical parameter in carbon cycle models with important implications for climate-carbon feedbacks in the 21st century. The common assumption of a constant Q10, usually with a value of 2.0, was shown to be invalid by a previous model-data fusion study that reported biome-specific values of this parameter. We extend the previous analysis by demonstrating that these biome-level values of Q10 also are a function of dryness (R2 = 0.54). When tundra and cultivated lands are excluded, the correlation is much stronger (R2 = 0.92). Therefore …


A Hybrid Agent-Based And Differential Equations Model For Simulating Antibiotic Resistance In A Hospital Ward, Lester Caudill, Barry Lawson Dec 2013

A Hybrid Agent-Based And Differential Equations Model For Simulating Antibiotic Resistance In A Hospital Ward, Lester Caudill, Barry Lawson

Department of Math & Statistics Faculty Publications

Serious infections due to antibiotic-resistant bacteria are pervasive, and of particular concern within hospital units due to frequent interaction among health-care workers and patients. Such nosocomial infections are difficult to eliminate because of inconsistent disinfection procedures and frequent interactions among infected persons, and because ill-chosen antibiotic treatment strategies can lead to a growth of resistant bacterial strains. Clinical studies to address these concerns have several issues, but chief among them are the effects on the patients involved. Realistic simulation models offer an attractive alternative. This paper presents a hybrid simulation model of antibiotic resistant infections in a hospital ward, combining …


Road Systems And Betweenness, Paul Bankston Dec 2013

Road Systems And Betweenness, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

A road system is a collection of subsets of a set—the roads—such that every singleton subset is a road in the system and every doubleton subset is contained in a road. The induced ternary (betweenness) relation is defined by saying that a point c lies between points a and b if c is an element of every road that contains both a and b . Traditionally, betweenness relations have arisen from a plethora of other structures on a given set, reflecting intuitions that range from the order-theoretic to the geometric and topological. In this paper we initiate a study …


The Detection Of A Light Echo From Sn 2007af, Dina Drozdov Dec 2013

The Detection Of A Light Echo From Sn 2007af, Dina Drozdov

All Theses

Type Ia supernovae are widely studied for their uniform properties, which make them ideal candidates for cosmological surveys. Although these exploding stars are popular targets, key funda-mental questions about their nature remain, and new techniques need to be developed to investigate the progenitor system and explosion mechanisms. Light echoes are created by light scattering off dust that reaches the observer after the direct path light from the explosion arrived and have been studied for the past 100 years. Light echoes from Type Ia supernovae are rare, with only a few cases being discovered in the past decades. Because light echoes …


Macroscopic Investigation Of Ionic- And Nano-Silver Toxicity To Soil Nitrification Process, Abdurrahman Masrahi Dec 2013

Macroscopic Investigation Of Ionic- And Nano-Silver Toxicity To Soil Nitrification Process, Abdurrahman Masrahi

All Theses

The worldwide production of engineered nanoparticles (ENPs) has grown rapidly in our era because of the popular applications in industrial and consumer markets. Especially silver (Ag) NP is one of mostly common ENPs in our consumer products due to its unique antimicrobial property. However, release of AgNPs into environment through wastewater treatment plants poses a question that what impact AgNPs have on microbially mediated processes in environment (e.g., nutrient and trace element cycles). In the last decades, numerous toxicological studies of AgNPs on bacteria have been conducted in pure culture systems, and several different antimicrobial mechanisms of AgNPs have been …


Virtualizing Intelligent River®: A Comparative Study Of Alternative Virtualization Technologies, Aravindh Sampathkumar Dec 2013

Virtualizing Intelligent River®: A Comparative Study Of Alternative Virtualization Technologies, Aravindh Sampathkumar

All Theses

Emerging cloud computing infrastructure models facilitate a modern and efficient way of utilizing computing resources, enabling applications to scale with varying demands over time. The core enabler of the cloud computing paradigm is virtualization. The concept is not new; virtualization has garnered significant research attention, fostering a race to achieve the lowest possible virtualization overhead. The evolution has led to three primary virtualization approaches: full-virtualization, para-virtualization, and container-based virtualization, each with a unique set of strengths and weaknesses. Thus it becomes important to study and evaluate their quantitative and qualitative differences. The operational requirements of the Intelligent River® middleware system …


Stimulated Raman Scattering In Micro Sphere Resonators, Ruoyu Zhang Dec 2013

Stimulated Raman Scattering In Micro Sphere Resonators, Ruoyu Zhang

All Theses

Micro sphere resonators that hold optical whisper gallery modes (WGMs) provide an innovative option for implementing micro optical resonators. The unique properties of the micro sphere resonator make it capable to introduce resonance for various optical phenomenon, like stimulated Raman scattering (SRS), in micron scale.

This thesis illustrates the characteristics of micro sphere resonators and demonstrates the resonance-enhanced SRS in micro sphere resonators with reduce threshold power. Both theoretical and experimental results are presented. Coupling model for WGM is derived in transfer matrix method. Simulation analyses for mode pattern of WGMs are solved based on mathematic model and finite element …


The Fabrication And Study Of Silver Nanoparticle Structures, Aubrie Pfirman Dec 2013

The Fabrication And Study Of Silver Nanoparticle Structures, Aubrie Pfirman

All Theses

Nanotechnology and the synthesis of nanoparticle systems are attractive in part because of interesting, tunable optical and electrical properties that are not observed with bulk material. Silver nanoparticles (Ag NPs) interact with visible light more efficiently than any other system due to the excitation of plasmon resonances, which are the collective oscillations of the free electron density. These collective oscillations produce an enhanced local electromagnetic (EM) field: this field is responsible for highly-utilized phenomena such as surface enhanced Raman scattering (SERS), enhanced fluorescence, surface enhanced infrared absorption (SEIRA), and many others. Many experiments have been conducted to optimize and tailor …


Room Generation, Removal, And Recovery In Udk 3.5, Scott Johnson Dec 2013

Room Generation, Removal, And Recovery In Udk 3.5, Scott Johnson

All Theses

This paper explores algorithms and techniques for creating an extended game world that represents a radical departure from the widely used static content in current use with most games featuring procedurally generated game worlds. Using the Unreal Development Kit 3.5 game engine and focusing on a small set of rooms and doors the research sets to create a game world that is in constant flux and addresses issues of game development limitations on the size of game worlds.