Physical Sciences and Mathematics Commons^™

Minimal And Near Minimal Congruence Lattice Representations Of Finite Lattices By Finite Algebras On Sets Of Integers, Roger Lee Bunn

Doctoral Dissertations

"We give finite congruence lattice representations of some finite distributive, modular and nonmodular lattices by means of finite algebras on sets of integers. These representations are minimal or near minimal as determined by ρ, a mapping from the class R of finitely representable lattices into the natural numbers N"--Abstract, page iii.

Applied Palynology: Multidisciplinary Case Studies From Egypt, Gulf Of Mexico And Usa, Mohamed K. Zobaa

Doctoral Dissertations

"Various applications of palynology have been used to study case studies from four different parts of the world, namely northern Egypt, offshore Gulf of Mexico, eastern Tennessee (USA), and New Orleans, Louisiana (USA). In these case studies, palynomorphs (spores, pollen, dinoflagellate cysts, and algae) have been utilized to define zones of hydrocarbon potential, reconstruct paleoenvironmental and paleoclimatic conditions, constrain the ages of the studied rock sequences, and express its potential as a replacement proxy for some expensive organic geochemical analyses. The ability to detect past hurricane activities and their associated damage to the geologic record is here presented as a …

A Geological And Geophysical Study Of The Tendaho Graben In The Afar Depression, Ethiopia: Insights Into Transitional Continental Rifting, David Lee Bridges

Doctoral Dissertations

"A detailed magnetic and gravity study across the Tendaho Graben (the Red Sea propagator within the Afar Depression, Ethiopia) revealed features that can best be interpreted as a continental rift undergoing oceanization. This NW-trending extensional structure is ~50 km wide and it is confined within well-developed NW-trending boarder faults that deform the 2 km thick and ~ 2 Ma basaltic flows of the Afar Stratoids. The age of the basaltic flows becomes progressively younger inward from the boarder faults until it reaches ~30,000 years close to the rift axis. The central part of the Tendaho Graben is characterized by a …

Quantum Electrodynamics And Fundamental Constants, Benedikt J. Wundt

Doctoral Dissertations

"The unprecedented precision achieved both in the experimental measurements as well as in the theoretical description of atomic bound states make them an ideal study object for fundamental physics and the determination of fundamental constants. This requires a careful study of the effects from quantum electrodynamics (QED) on the interaction between the electron and the nucleus.

The two theoretical approaches for the evaluation of QED corrections are presented and discussed. Due to the presence of two energy scales from the binding potential and the radiation field, an overlapping parameter has to be used in both the approaches in order to …

Increasing The Accuracy Of Protein Three-Dimensional Structure Comparison, Mauricio J. Arriagada-Benitez

Dissertations and Theses @ UNI

Structural alignment is an important tool for identifying structural and functional relationships between proteins. A typical protein structure alignment method is an iterative algorithm that computes an optimal residue-residue correspondence, once for each inspected spatial superposition of the input proteins. The significance of this study allows us to better understand how important it is to explore in deep the analysis of proteins structure using a residue pair distance as the way to align two proteins. We assess the extent of improvements in the accuracy of the existing methods that can be made by exploring the search space in a more …

Modeling Hourly Electricity Prices: A Structural Time Series Approach Incorporating Modified Garch Innovations, Edirisinghe Mudiyanselage Asitha Edirisinghe

Doctoral Dissertations

"The main objective of this research is to develop time series based procedures for modeling day-ahead and real-time hourly electricity prices. Such empirical processes exhibit features that make the direct application of standard time series models infeasible. Four years of hourly day-ahead and real-time electricity price data from the region supplied by the American Electric Power (AEP) company through the PJM Regional Transmission Organization (RTO) and one half years of real-time electricity prices from the MISO RTO are utilized as an empirical basis for developing such procedures. The price data show several features, such as irregular seasonal behavior, weekly and …

Multiple Differential Study Of Fragmentation Processes In 75 Kev Proton-Molecular Hydrogen Collisions, Kisra Nayomal Egodapitiya

Doctoral Dissertations

"Double Differential Cross Sections (DDCS) were measured for single ionization of H₂ by 75 keV proton (p) impact as a function of the projectile scattering angle (θp) for a fixed energy loss (ΔE) for two different target-collimating slit distances, which determined the width of the projectile wave packet (Δx). In one case Δx was larger than the inter-nuclear separation of the H₂ molecule (coherent projectile beam), while for the other case it was much smaller than the inter-nuclear separation (incoherent projectile beam). A Young type interference pattern was observed in the coherent data, but this was not present in the …

First-Principles Studies Of Complex Hydrides For Li-Ion Battery And Hydrogen Storage Applications, Timothy Hudson Mason

Doctoral Dissertations

"We employ density functional theory in a computational study of two energy storage systems.

In the first, we explore the thermodynamic viability of light metal hydrides as a high capacity Li-ion battery negative electrode. Given a set of solid-state and gas-phase reactants, we have determined the phase diagram in the Li-Mg-B-N-H system in the grand canonical ensemble as a function of lithium electrochemical potential. We present computational results for several new conversion reactions with predicted capacities between 2400 and 4000 mAhg⁻¹ that are thermodynamically favorable and that do not involve gas evolution. We provide experimental evidence for the reaction pathway …

Interfacial Effects On Dielectric Properties Of Polymer-Particle Nanocomposites, Sasidhar Siddabattuni

Doctoral Dissertations

"Dielectric materials that are capable of efficiently storing large amounts of electrical energy are desirable for many electronic and power devices. Since the electrical energy density in a dielectric material is limited to εV_b²/2, where ε is the dielectric permittivity of the material and V_b is the breakdown strength, increased permittivity and breakdown strength are required for large energy storage density. Interfacial effects can influence the dielectric properties, especially dielectric breakdown resistance in polymer-particle nanocomposites. Several functional organophosphates were used to modify the surface of titania and barium titanate nanofiller particles in order to achieve covalent interface …

Ceeme: Compensating Events Based Execution Monitoring Enforcement For Cyber-Physical Systems, Thoshitha T. Gamage

Doctoral Dissertations

"Fundamentally, inherently observable events in Cyber-Physical Systems with tight coupling between cyber and physical components can result in a confidentiality violation. By observing how the physical elements react to cyber commands, adversaries can identify critical links in the system and force the cyber control algorithm to make erroneous decisions. Thus, there is a propensity for a breach in confidentiality leading to further attacks on availability or integrity. Due to the highly integrated nature of Cyber-Physical Systems, it is also extremely difficult to map the system semantics into a security framework under existing security models. The far-reaching objective of this research …

Epitaxial Electrodeposition Of Metal Oxide Films And Superlattices Which Exhibit Resistance Switching, Rakesh V. Gudavarthy

Doctoral Dissertations

"This dissertation presents an investigation of the electrodeposition of metal oxide films and superlattices on conducting polycrystalline and single crystal substrates. In the first part of the study, electrodeposition of magnetite (Fe₃O₄) films and superlattices in the magnetite/zinc ferrite system which exhibit resistance switching is studied. Paper I reports the electrodeposition of superlattices in the magnetite/zinc ferrite system and shows that only superlattices exhibit multistate resistance switching. In paper II, simple polycrystalline magnetite films electrodeposited on stainless steel crystals exhibit multistate resistance switching which can be tuned by controlling the composition of the films. Paper II describes the epitaxial electrodeposition …

Decolorization Of Dyes And Distillery Waste Effluent: Comparison Of The Effectiveness Of Several Biological And Physico-Chemical Processes, Mylène Godin

Dissertations and Theses @ UNI

Dyes and pigments are used extensively in many important industries. They are also important environmental contaminants and must be removed in a cost-effective manner from wastewater. The present investigation focuses on the use of several inexpensive physico-chemical and biological systems. The goal is to assess and compare their ability to decolorize water containing a representative triphenylmethane dye ( crystal violet), a representative azo dye (Congo red), and a rum distillery waste effluent, also known as still bottoms. The selected processes were photodegradation, ozonation, adsorption and bioremediation. Photodegradation was studied with three light sources, namely a commercially available 42 Watt fluorescent …

Cross-Layer Design For Network Performance Optimization In Wireless Networks, Xuan Gong

Doctoral Dissertations

"In this dissertation, I use mathematical optimization approach to solve the complex network problems. Paper l and paper 2 first show that ignoring the bandwidth constraint can lead to infeasible routing solutions. A sufficient condition on link bandwidth is proposed that makes a routing solution feasible, and then a mathematical optimization model based on this sufficient condition is provided. Simulation results show that joint optimization models can provide more feasible routing solutions and provide significant improvement on throughput and lifetime. In paper 3 and paper 4, an interference model is proposed and a transmission scheduling scheme is presented to minimize …

Assessing The Usability Of A Wearable Computer Interface With Split Button Configuration, Lisa A. Jamba

UNF Graduate Theses and Dissertations

A wearable computer interface with split button configuration was constructed using Arduino Lilypad components on the front of a vest with the goal of assessing its usability in an activity involving at least one hand. A sample of twelve men and eight women ages 18 to 62 participated in a usability study of the vest. The activity chosen for this study was a typing test during which users would control a media player remotely with the vest. The usability measures included ease of use, performance of the interface as determined by accuracy rates and time to task completion for both …

Defining Routing Policies In Peer-To-Peer Overlay Networks, Michael Pickering

UNF Graduate Theses and Dissertations

This master’s thesis involves the definition and development of a policy-based routing scheme for peer-to-peer overlay networks. Many peer-to-peer networks are in existence today and each has various methods for discovering new peers, searching for content, and overcoming connectivity problems. The addition of efficient policy-based routing enhances the ability of peers within overlay networks to make appropriate routing decisions. Policy-based routing provides a means for peers to define the types of network traffic they are willing to route and the conditions under which they will route it. The motivations for these policies are many and are described in upcoming sections. …

Performance Of Bfsa Based Anti-Collision Protocols For Rfid Networks Supporting Identical Tags, Kirti Chemburkar

UNF Graduate Theses and Dissertations

Radio Frequency Identification (RFID) is a powerful emerging technology widely used for asset tracking, supply chain management, animal identification, military applications, payment systems, and access control. Over the years, RFID has emerged as a popular technology in various industries because of its ability to track moving objects. As RFID is becoming less expensive and more robust, many companies and vendors are developing tags to track objects. Multiple vendors manufacture RFID tags worldwide. Therefore, it is quite possible that they manufacture tags with the same identification code (ID) as vendor ID code data sets may not be synchronized or may be …

On The Design Of Web Services: Soap Vs. Rest, Pavan Kumar Potti

UNF Graduate Theses and Dissertations

The purpose of this thesis is to compare the performance characteristics of Simple Object Access Protocol (SOAP) and Representational State Transfer (REST), which are methods of supporting interactions among Web services. They differ in both context and usage; SOAP is a protocol while REST is architecture. SOAP is a well-developed protocol used in the Web industry and is standardized by the World Wide Web Consortium (W3C). REST is the outcome of Dr. Roy Thomas Fielding’s 2000 PhD dissertation, “Architectural Styles and the Design of Network-Based Software Architecture.” REST is gaining in popularity due to its simplicity, scalability, and architectural dependence …

The Weil Pairing On Elliptic Curves And Its Cryptographic Applications, Alex Edward Aftuck

UNF Graduate Theses and Dissertations

This thesis presents the Weil pairing on elliptic curves as a tool to implement a tripartite Diffie-Helman key exchange. Elliptic curves are introduced, as well as the addition operation that creates a group structure on its points. In leading to the definition of the Weil pairing, divisors of rational functions are studied, as well as the Weierstrass }-function, which shows the complex lattice as isomorphic to elliptic curves. Several important qualities of the Weil pairing are proved, and Miller's algorithm for quick calculation is shown. Next, the bipartite Diffie-Helman key exchange is discussed over finite fields and elliptic curves. Finally …

Dynamic Light Scattering And Zeta Potential Of Colloidal Mixtures Of Amelogenin And Hydroxyapatite In Calcium And Phosphate Rich Ionic Milieus, Vuk Uskoković, Roselyn Odsinada, Sonia Djordjevic, Stefan Habelitz

Pharmacy Faculty Articles and Research

The concept of zeta-potential has been used for more than a century as a basic parameter in controlling the stability of colloidal suspensions, irrespective of the nature of their particulate ingredients – organic or inorganic. There are prospects that self-assembly of peptide species and the protein-mineral interactions related to biomineralization may be controlled using this fundamental physicochemical parameter. In this study, we have analyzed the particle size and zeta-potential of the full-length recombinant human amelogenin (rH174), the main protein of the developing enamel matrix, in the presence of calcium and phosphate ions and hydroxyapatite (HAP) particles. As calcium and phosphate …

Understanding Streaming In Dictyostelium Discoideum: Theory Versus Experiments, J. C. Dallon, Brittany Dalton, Chelsea Malani

Faculty Publications

Recent experimental work involving Dictyostelium discoideum seems to contradict several theoretical models. Experiments suggest that localization of the release of the chemoattractant cyclic adenosine monophosphate to the uropod of the cell is important for stream formation during aggregation. Yet several mathematical models are able to reproduce streaming as the cells aggregate without taking into account localization of the chemoattractant. A careful analysis of the experiments and the theory suggests the two major features of the system which are important to stream formation are random cell motion and chemotaxis to regions of higher cell density. Random cell motion acts to reduce …

Density And Temperature Scaling Of Disorder-Induced Heating In Ultracold Plasmas, Scott D. Bergeson, A. Denning, M. Lyon, F. Robicheaux

Faculty Publications

We report measurements and simulations of disorder-induced heating in ultracold neutral plasmas. Fluorescence from plasma ions is excited using a detuned probe laser beam while the plasma relaxes from its initially disordered nonequilibrium state. This method probes the wings of the ion velocity distribution. The simulations yield information on time-evolving plasma parameters that are difficult to measure directly and make it possible to connect the fluorescence signal to the rms velocity distribution. The disorder-induced heating signal can be used to estimate the electron and ion temperatures ~100 ns after the plasma is created. This is particularly interesting for plasmas in …

Stern-Gerlach Dynamics With Quantum Propagators, Bailey C. Hsu, Manuel Berrondo, Jean F. Van Huele

Faculty Publications

We study the quantum dynamics of a nonrelativistic neutral particle with spin in inhomogeneous external magnetic fields. We first consider fields with one-dimensional inhomogeneities, both unphysical and physical, and construct the corresponding analytic propagators. We then consider fields with two-dimensional inhomogeneities and develop an appropriate numerical propagation method. We propagate initial states exhibiting different degrees of space localization and various initial spin configurations, including both pure and mixed spin states. We study the evolution of their spin densities and identify characteristic features of spin density dynamics, such as the spatial separation of spin components, and spin localization or accumulation. We …

Synthesis And Physicochemical Properties Of Cationic Microgels Based On Poly(N-Isopropylmethacrylamide), Xiaobo Hu, Zhen Tong, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Surfactant-free, radical precipitation copolymerization of N-isopropylmethacrylamide and the cationic co-monomer N-(3-aminopropyl) methacrylamide hydrochloride (APMH) was carried out to prepare microgels functionalized with primary amines. The morphology and hydrodynamic diameter of the microgels were characterized by atomic force microscopy and photon correlation spectroscopy, with the effect of NaCl concentration and initiator type on the microgel size and yield being investigated. When a 2,2'-azobis (2-amidinopropane) dihydrochloride (V50)-initiated reaction was carried out in pure water, relatively small microgels (similar to 160 nm in diameter) were obtained in low yield (similar to 20%). However, both the yield and size increased if the reaction was …

An Upper Limit For Macromolecular Crowding Effects, Andrew C. Miklos, Congang Li, Courtney D. Sorell, L. Andrew Lyon, Gary J. Pielak

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Solutions containing high macromolecule concentrations are predicted to affect a number of protein properties compared to those properties in dilute solution. In cells, these macromolecular crowders have a large range of sizes and can occupy 30% or more of the available volume. We chose to study the stability and ps-ns internal dynamics of a globular protein whose radius is similar to 2 nm when crowded by a synthetic microgel composed of poly(N-isopropylacrylamide-co-acrylic acid) with particle radii of similar to 300 nm.

Results: Our studies revealed no change in protein rotational or ps-ns backbone dynamics and only mild …

Bulk Modulus Of Poly(N-Isopropylacrylamide) Microgels Through The Swelling Transition, B. Sierra-Martin, Y. Laporte, A. B. South, L. Andrew Lyon, A. Fernandez-Nieves

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report measurements of the bulk modulus of individual poly(N-isopropylacrylamide) microgels along their swelling transition. The modulus is determined by measuring the volume deformation of the microgel as a function of osmotic pressure using dextran solutions. We find that the modulus softens through the transition, displaying a nonmonotonous behavior with temperature. This feature is correctly reproduced by the theory of Flory for polymer gels, once the concentration dependence of the solvency parameter is properly incorporated.

Evaluation Of Satellite-Retrieved Extreme Precipitation Rates Across The Central United States, A. Aghakoucak, A. Behrangi, S. Sorooshian, K. Hsu, Eyal Amitai

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Water resources management, forecasting, and decision making require reliable estimates of precipitation. Extreme precipitation events are of particular importance because of their severe impact on the economy, the environment, and the society. In recent years, the emergence of various satellite-retrieved precipitation products with high spatial resolutions and global coverage have resulted in new sources of uninterrupted precipitation estimates. However, satellite-based estimates are not well integrated into operational and decision-making applications because of a lack of information regarding the associated uncertainties and reliability of these products. In this study, four satellite-derived precipitation products (CMORPH, PERSIANN, TMPA-RT, and TMPA-V6) are evaluated with …

The Integrated Wrf/Urban Modeling System: Development, Evaluation, And Applications To Urban Environmental Problems, Fei Chen, Hiroyuki Kusaka, Robert Bornstein, Jason Ching, C.S.B. Grimmond, Susanne Grossman-Clarke, Thomas Loridan, Kevin W. Manning, Alberto Martilli, Shiguang Miao, David J. Sailor, Francisco P. Salamanca, Haider Taha, Mukul Tewari, Xuemei Wang, Andrzej A. Wyszogrodzki, Chaolin Zhang

Mechanical and Materials Engineering Faculty Publications and Presentations

To bridge the gaps between traditional mesoscale modeling and microscale modeling, the National Center for Atmospheric Research (NCAR), in collaboration with other agencies and research groups, has developed an integrated urban modeling system coupled to the Weather Research and Forecasting (WRF) model as a community tool to address urban environmental issues. The core of this WRF/urban modeling system consists of: 1) three methods with different degrees of freedom to parameterize urban surface processes, ranging from a simple bulk parameterization to a sophisticated multi-layer urban canopy model with an indoor outdoor exchange sub-model that directly interacts with the atmospheric boundary layer, …

Aerosol Climatology Over Nile Delta Based On Modis, Misr And Omi Satellite Data, H. S. Marey, J. C. Gille, Hesham El-Askary, E. A. Shalaby, Mohamed El Raey

Mathematics, Physics, and Computer Science Faculty Articles and Research

Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the “black cloud” during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr period from 2000–2009. Significant monthly variability is observed in the AOD with maxima in April or May (_0.5) and October (_0.45), and a …

Two-Language, Two-Paradigm Introductory Computing Curriculum Model And Its Implementation, Vladimir Zanev, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

This paper analyzes difficulties with the introduction of object-oriented concepts in introductory computing education and then proposes a two-language, two-paradigm curriculum model that alleviates such difficulties. Our two-language, two-paradigm curriculum model begins with teaching imperative programming using Python programming language, continues with teaching object-oriented computing using Java, and concludes with teaching object-oriented data structures with Java.

Aerosol Properties Over The Indo‐Gangetic Plain: A Mesoscale Perspective From The Tigerz Experiment, D. M. Giles, B. N. Holben, Sachchida N. Tripathi, Thomas F. Eck, W. Wayne Newcomb, Ilya Slutsker, Russell R. Dickerson, Anne M. Thompson, Shana Mattoo, Sheng-Hsiang Wang, Ramesh P. Singh, Aliaksandyr Sinyuk, Joel S. Schafer

Mathematics, Physics, and Computer Science Faculty Articles and Research

High aerosol loading over the northern Indian subcontinent can result in poor air quality leading to human health consequences and climate perturbations. The international 2008 TIGERZ experiment intensive operational period (IOP) was conducted in the Indo-Gangetic Plain (IGP) around the industrial city of Kanpur (26.51 degrees N, 80.23 degrees E), India, during the premonsoon (April-June). Aerosol Robotic Network (AERONET) Sun photometers performed frequent measurements of aerosol properties at temporary sites distributed within an area covering similar to 50 km(2) around Kanpur to characterize pollution and dust in a region where complex aerosol mixtures and semi-bright surface effects complicate satellite retrieval …