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Spark-Induced Sparks As A Mechanism Of Intracellular Calcium Alternans In Cardiac Myocytes, Robert J. Rovetti, Xiaohua Cui, Alan Garfinkel, James N. Weiss, Zhilin Qu

Mathematics, Statistics and Data Science Faculty Works

Rationale: Intracellular calcium (Ca) alternans has been widely studied in cardiac myocytes and tissue, yet the underlying mechanism remains controversial.

Objective: In this study, we used computational modeling and simulation to study how randomly occurring Ca sparks interact collectively to result in whole-cell Ca alternans.

Methods and Results: We developed a spatially-distributed intracellular Ca cycling model in which Ca release units (CRUs) are locally coupled by Ca diffusion throughout the myoplasm and sarcoplasmic reticulum (SR) network. Ca sparks occur randomly in the CRU network when periodically paced with a clamped voltage waveform, but Ca alternans develops as the pacing speeds …

Synthesis, Characterization And Biological Activity Of Copper (Ii) And Zinc (Ii) Complexes Of Thiosemicarbazones And Their N(4)-Substituted Derivatives Derived From 2,4-Dihydroxybenzaldehyde., Tan Kong Wai

Student Works (2010-2019)

Four thiosemicarbazones ligands (1-4) have been prepared with good yield by refluxing 2,4-dihydroxybenzaldehyde with thiosemicarbazide or N(4)-substituted thiosemicarbazide in ethanol or methanol. From these four ligands, 16 new ternary metal complexes (5-20) with the general formulation of M(B)L have been prepared from the reactions of metal acetates with 2,4-dihydroxybenzaldehyde N(4)-substituted thiosemicarbazone in the presence of N,N-heterocyclic base (M2+ = Zn2+ or Cu2+; B = 2,2'-bipyridine, (bpy); 1,10-phenanthroline, (phen); L2- = doubly deprotonated thiosemicarbazones = 2,4-dihydroxybenzaldehyde thiosemicarbazonato, (HT); 2,4-dihydroxybenzaldehyde 4-methylthiosemicarbazonato, (HM); 2,4-dihydroxybenzaldehyde 4-ethylthiosemicarbazonato, (HE) and 2,4-dihydroxybenzaldehyde 4-phenylthiosemicarbazonato, (HP)) These compounds have been characterized by elemental analyses, IR, UV-Vis, NMR and magnetic …

Image Edge Detection Using Ant Colony Optimization, Carlos M. Oppus, Anna Veronica Baterina

Department of Information Systems & Computer Science Faculty Publications

Ant colony optimization (ACO) is a population-based metaheuristic that mimics the foraging behavior of ants to find approximate solutions to difficult optimization problems. It can be used to find good solutions to combinatorial optimization problems that can be transformed into the problem of finding good paths through a weighted construction graph. In this paper, an edge detection technique that is based on ACO is presented. The proposed method establishes a pheromone matrix that represents the edge information at each pixel based on the routes formed by the ants dispatched on the image. The movement of the ants is guided by …

Mapping The Reactivity Surface Of Metal-Olefin Reactions, Joshua Davis, Stephen A. Matchett

Student Summer Scholars Manuscripts

Our overall goal of our project was to map susceptibility for nucleophilic attack on a series of metal-olefin compounds as a function of their geometry. The scope of this paper, however, is directed toward stabilizing our reactants in solution and the developing methods to test the reaction. In order to measure the susceptibility on the series we must know three things: the initial concentration of the nucleophile and the metal-olefin as well as a way measure the rate of reaction. In order to take these measurements, the solvent used must not interact with either reactant, must not interfere with the …

Selected Studies Of Orbital Stability And Habitability In Star-Planet Systems, William Jason Eberle

Physics Dissertations - Archive

The study of planets remaining in orbit around one star with another starinterfering is an important topic of orbital mechanics and astrobiology. The onset of instability for a planet which is part of a stellar binary system is investigated by performing numerical simulations of the circular restricted three body problem. Synodic velocity phase space portraits are used with the hodograph in order to obtain a new criterion for determining planetary stability. The stability limits obtained via these methods agree with previous methods that were obtained based on simulations over much longer time intervals. In addition, the timely case of a …

Synthesis Of Cdte And Pbs Semiconductor Quantum Dots And Their Biological And Photochemical Applications, Xing Zhang

Physics Theses - Archive

Semiconductor quantum dots are inorganic nanoparticles with unique photophysical properties. In particular, water soluble quantum dots which have been synthesized by colloidal chemistry in aqueous environment are highly luminescent. Their huge absorption cross sections, tunable, narrow emission bands and effectiveness of surface functionality have stimulated these luminescent probes in various applications like biological sensors as well as imaging contrast agents. In this paper we will discuss several aspects about the synthesize processes of the water soluble, highly luminescent type of CdTe quantum dots and its near infrared counterpart HgxCd1-xTe, the extremely crystallized PbS quantum dots with the application of the …

Search For Standard Model Higgs In Two Photon Final State At Atlas, Hyeon Jin Kim

Physics Dissertations - Archive

The Standard Model of particle physics describes very precisely the nuclear strong and weak forces and the eletromagnetic interaction, by the exchange of vector bosons. It also describes all matter as composed of quarks and leptons and predicts their interactions. The Higgs boson is the last missing piece of the Standard Model, yet to be observed. The search for the Higgs particle is one of the most important goals of the ATLAS experiment at the Large Hadron Collider (LHC). The ATLAS electromagnetic (EM) calorimeter is a crucial subdetector system of the ATLAS detector in searching for the Higgs boson, in …

The Role Of The Y-Component Of The Interplanetary Magnetic Field In Transpolar Saturation And Ring Current Response As Found In Data And Simulation, Elizabeth Joy Mitchell

Physics Dissertations - Archive

Energy is transferred into the magnetosphere of Earth through merging of magnetic fields (Dungey cycle and lobe cell convection) and through momentum transfer across the magnetopause (viscous interactions). These processes cause enhanced plasma convection in the inner magnetosphere and ionosphere, which in turn form the ring current and the transpolar potential, respectively. These processes have been studied extensively with regard to the role of the north-south component of the interplanetary magnetic field (IMF). The role of the dawn-dusk IMF is less well known.We use the LFM global MHD simulation, the CRCM, and data to quantify the transpolar potential and ring …

Global Behavior Of Difference Equations, Ann M. Brett

Open Access Dissertations

In my first manuscript, I investigate the global stability character of the equilibrium points and the period-two solutions of [special characters omitted] with positive parameters and nonnegative initial conditions. I show that every solution of the equation in the title converges to either the zero equilibrium, the positive equilibrium or the period-two solution, for all values of parameters outside of a specific set defined in the paper. In the case when the equilibrium points and period-two solution coexist I give a precise description of the basins of attraction of all points. My results give an affirmative answer to Conjecture 9.5.6 …

Student And Faculty Perspectives Of A Scalable, Sustainable, Higher Education, Learning-Rich Classroom, Jace Hargis, Peter J. Schroeder

Eberhardt School of Business Faculty Articles

This article profiles the development of a sustainable, learning-rich room and provides student and faculty perspectives on its effectiveness. The room features mobile furniture and instructional technology - interactive whiteboard, student response systems and FLIP camcorders. Three faculty members were selected to use the classroom for instruction. Data was collected via student surveys and videos as well as faculty meetings, videos, surveys, and reports. Faculty made extensive use of the classroom infrastructure by employing a wide variety of active teaching methods. The success of the Learning Lab resulted has given administration new opportunities to explore innovative teaching through building learning …

The Role Of Corporate Law In Preventing A Financial Crisis: Reflections On In Re Citigroup Inc. Shareholder Derivative Litigation, Franklin A. Gevurtz

McGeorge School of Law Scholarly Articles

No abstract provided.

Dimethylmercury Production In Freshwater Sediments, David C. Kelly

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Dimethylmercury (DMHg) has been examined almost exclusively in marine environments to date, plays an uncertain role in the global cycling of Hg, and is produced by a currently unknown mechanism in natural systems. We examined DMHg production in microcosms containing 100 cm3 of freshwater sediment sampled from 3 wetlands and a lake near Dayton, Ohio. DMHg was produced from all sediments analyzed, and found that production is increased significantly by the addition of inorganic Hg from ~0.1pM to ~10pM, its production is unaffected by autoclaving the sediment, and organic carbon additions had no discernible effect on production. Its total concentrations …

Extent And Effects Of Selection To Reduce Synthetic Cost Of Highly Expressed Proteins, Esley Marvin Heizer Jr

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Organisms that preferentially utilize less biosynthetically expensive amino acids in highly expressed genes exhibit metabolic efficiency. Exploration of this phenomenon has been limited to six prokaryotes.

I present a large scale analysis of metabolic efficiency in prokaryotic organisms and analysis of two eukaryotes (Saccharomyces cerevisiae and humans). Examination of 73 bacteria reveals the presence of metabolic efficiency in 66 organisms. The average correlation between amino acid biosynthetic cost and CAI scores in these organisms is -0.21. The seven organisms that did not exhibit metabolic efficiency are all Lactobacilli and highly auxotrophic. Saccharomyces cerevisiae exhibits significant trends between average amino acid …

Computational Study Of Direct Fuel Injection In The Rotax 914 Engine, Brad Pollock

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Direct injection spark ignition (DISI) is a fuel delivery method in which the fuel is introduced directly into the combustion chamber of an internal combustion engine. Although direct fuel injection was first pioneered in the early 1920's, it has only recently become a reliable option due to advances made in control systems and injection technology. Direct injection enables increased fuel efficiency and higher power output than a conventional Port Fuel Injection (PFI) system. By delivering pressurized fuel directly into the cylinder, the degree of fuel atomization and the fuel vaporization rate are increased. Hence, the air/fuel mixture can be more …

Predicting Sales Performance: Considering Nonlinear Relationships Between Gma, Performance, And Effectiveness, Jason D. Culbertson

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Measuring Conscientiousness with Explicit and Implicit Measures Although the literature has a wealth of research predicting salesperson performance, the literature is unclear. Even meta-analytic research (Barrick et al., 2001; Schmidt & Hunter, 1998; Vinchur et al. 1998) appears inconsistent. The main goal of this study was to determine if the relationships were of a nonlinear nature and leading to confusion. This study found that the relationships between sales performance depended on the type of criteria (supervisor ratings or performance versus sales revenue or effectiveness) and the type of relationship examined (linear or nonlinear). This study was successful in demonstrating a …

Ostwald Ripening Of Iron (Fe) Catalyst Nanoparticles On Aluminum Oxide Surfaces (Al2O3) For The Growth Of Carbon Nanotubes, Roberto I. Acosta

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Theoretical models have proposed that the nucleation and growth mechanism of carbon nanotubes (CNTs) has been affected by the catalytic activity of transition metals. The catalyst behavior during growth has been mainly associated as the responsible mechanism for the termination of CNT growth. Although several hypotheses have been developed to explain this mechanism, is still today an unresolved phenomenon. It was recently shown that the Ostwald ripening of iron (Fe) nanoparticles played a dominant role in the termination of CNT growth. The Ostwald ripening mechanism was further investigated as a function of thermal annealing in Hydrogen (H₂) for …

Thermal And Electrochemical Characterization Of Cathode Materials For High Temperature Lithium-Ion Batteries In Ionic Liquids, Jodie R. Shoaf

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Finding a cathode material to operate a high-temperature Li-ion battery in the presence of an ionic liquid has become an attractive area of research. Three cathode materials, LiCoO2, Li4Ti5O12, and LiFePO4, were received from Electrochemical Systems Inc. of Knoxville, TN. Three ionic liquids were synthesized using a 1-alkyl-3-methylimidazolium (XMI+) cation, where the alkyl group was either ethyl, pentyl or hexyl, and contained a bis(pentafluoroethylsulfonyl)imide (Beti-) anion. The thermal and electrochemical properties of each ionic liquid, of each cathode material, and each combination of cathode material in the presence of ionic liquid were studied. All of the ionic liquids were found …

An Improved Genetic Algorithm For Knapsack Problems, Taskiran, Gamze Kilincli

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In this study, an improved genetic algorithm (GA) is presented to solve the multidimensional 0-1 knapsack problem (MKP). The MKP is a well-known combinatorial optimization problem and has received wide attention from the operations research community for decades. Although recent advances in computing and optimization technologies have made the solution of small and medium size instances possible, this NP-hard problem, in general, still remains one of the challenging problems yet to be solved.

Of the various algorithms developed to solve the MKP, GA seems to be one of the best methods pointed out in the literature. A GA is an …

The Harmonic Distortion Reduction Of Phase-Angle Fired Scrs Feeding A Resistive Load Using Fuzzy Logic, Matthew A. Clark

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High power silicon controlled rectifiers (SCR) are used in the application of infrared radiation testing. A case study has been performed on a department of defense facility utilizing SCRs to transfer electrical energy to thermal energy. The facility is capable of generating up to 5000 °F across large cross-sectional areas, requiring tens of megawatts of power. The combination of high power, unbalanced loads, and SCR switching generate high harmonic disturbances that offer significant challenges for conventional linear control systems. In addition, unbalanced three-phase distribution systems are difficult to model, specifically during switching transients. Fuzzy logic is used to characterize the …

How The Growth Of The Frampton Fold Affected The Growth Of The Green Knoll Diapir, John A. Zinck

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The growth of structural features formed by the movement of the Louann Salt within the study area follows a fold-first model (Rowan et al., 2000), in which the formation of the Frampton Fold predates the formation of the Green Knoll Diapir. The Frampton Fold was formed during two growth episodes driven by movement of the Louann Salt within the study area. The folding and faulting resulting from these growth episodes created a conduit through which the autochthonous Louann Salt was extruded to the sea floor during the Pliocene. Following a depositional episode consisting of the early sequences of the Mississippi …

Population Fit Threshold: Fully Automated Signal Map Generation For Baseline Correction In Nmr-Based Metabolomics, Daniel C. Homer

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Baseline correction of NMR-based metabolomic spectra is a key step in data processing to elucidate biomarkers of diseased and toxic states. Automated baseline correction methods often use human-selected parameters. Presented is a method for automated baseline correction using parameters selected from and without manipulation of the spectrum. The focus is on generating an accurate signal map based on the differentiating characteristics of baseline noise and signal. The presented method of signal map generation and baseline correction was developed and tested on 13C and 1H NMR spectra. The spectra were as simple as chemical standards containing less than 25 signal peaks …

Estimating Evapotranspiration Using Remote Sensing: A Hybrid Approach Between Modis Derived Enhanced Vegetation Index, Bowen Ratio System, And Ground Based Micro-Meteorological Data, Sumantra Chatterjee

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We investigated water loss by evapotranspiration (ET) from the Palo Verde Irrigation District (PVID) and the Cibola National Wildlife Refuge (CNWR) in southern California bordering the Colorado River collaborating with the United States Bureau of Reclamation (U.S.B.R.). We developed an empirical model to estimate ET for the entire PVID using satellite derived MODIS enhanced vegetation index (EVI), and ground based measurements of solar radiation and vapor pressure. We compared our predictions with U.S.B.R. estimates through statistical cross validation and showed they agree with an error less than 8%. We tested the same model for an alfalfa field inside PVID to …

Exploration Using Reaction Temperature To Tailor The Degree Of Order In Micro-Block Copolymer Proton Exchange Membranes, John Quentin Buquoi Iii

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The ability to control the self-assembly of sulfonated poly(arylene ether) sulfones (s-PAESs) was explored by tailoring rate coefficients, via temperature, in an A₂ + B₂ + B₂' Nucleophilic Aromatic Substitution (S_NAr) approach. The reactivity of various electrophilic sites were studied and tuned, via temperature control, to elicit a range of more ordered and disordered polymers of equivalent monomeric composition. These polymers were characterized by ¹H and ¹³C NMR spectroscopy and found to have highly disordered polymer configuration at higher temperatures while having a more regular configuration at lower temperatures.

Atmospheric Effects On The Propagation Of Mmw And Sub-Mmw Radiation, John S. Cetnar

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This thesis is a study of the propagation of millimeter wavelength (MMW) and submillimeter wavelength (sub-MMW) electromagnetic radiation (a.k.a. THz radiation) through the Earth's atmosphere. THz radiation is electromagnetic radiation that exists between the microwave and far infrared regions of the electromagnetic spectrum. It is nonionizing radiation but can penetrate through materials that are opaque to visible light so therefore has many new and useful applications. Unfortunately, THz radiation is heavily attenuated by the Earth's atmosphere as it propagates through it. This therefore represents a challenge to communications and sensing applications at millimeter and sub-millimeter wavelengths. In this work, the …

Development Of An Efficient Super-Resolution Image Reconstruction Algorithm For Implementation On A Hardware Platform, Pestak Thomas C.

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There is a growing demand from numerous commercial and military applications for images with ever-improving spatial resolution. However, there are resolution-limiting factors inherent in all imaging systems. Decreasing pixel sizes and/or increasing sensor arrays are not always viable. Super-Resolution (SR) Image Reconstruction is an image processing technique that restores a high-resolution (HR) image from a series of low-resolution (LR) images of a particular scene. Recently, there has been extensive research on robust SR algorithms used for post-processing. The goal of this thesis is to explore the current SR research and design computationally efficient SR algorithms for real-time processing based on …

Millennial Students Who Go Directly To Graduate School: Influences On This Decision And The Characterization Of Their Experience, Courtney A. Smith

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The purpose of this research study was to explore the issues surrounding Millennial students who go directly into graduate school after completing an undergraduate degree including what influenced this decision and how the students characterized the experience. Participants were interviewed and several themes emerged from this study: feeling not ready for the real world or qualified to work, differences and difficulties of graduate life compared to undergraduate life, more academic support is needed before and during graduate school, relationships with parents were evolving towards independence, the importance of grades, lack of campus involvement in graduate school, overcoming personal and academic …

Quantitative Structure-Activity Relationships For Organophosphates Binding To Trypsin And Chymotrypsin, Christopher Daniel Ruark

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Organophosphate (OP) nerve agents such as sarin, soman, tabun, and O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) do not react solely with acetylcholinesterase (AChE). Evidence suggests that a wide range of cholinergic-independent pathways are also targeted, including serine proteases. These proteases comprise nearly one-third of all known proteases and play major roles in synaptic plasticity, learning, memory, neuroprotection, wound healing, cell signaling, inflammation, blood coagulation and protein processing. Inhibition of these proteases by OPs was found to exert a wide range of noncholinergic effects depending on the type of OP, the dose, and the duration of exposure. Consequently, in order to understand …

Surveillance In A Smart Home Environment, Ryan Stewart Patrick

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A system for assisting the elderly in maintaining independent living is currently being designed. When mature, it is expected that this system will have the ability to track objects that a resident may lose periodically, detect falls within the home, and alert family members or health care professionals to abnormal behaviors.

This thesis addresses the early stages of this system's development. It presents a survey of the work that has previously been completed in the area of surveillance within a home environment, information on the physical characteristics of the system that is being designed, early results related to this system, …

A Structured Asic Approach To A Radiation Hardened By Design Digital Single Sideband Modulator For Digital Radio Frequency Memories, Thomas B. Pemberton

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Digital Radio Frequency Memories (DRFM) are widely used as modules in digital signal processing. These modules can provide several forms of signal manipulation and storage capabilities. With single event effects caused by environmental radiation the need for a radiation hardened DRFM is increased. Typical radiation hardening involves the use of specialized foundries utilizing proprietary CMOS libraries that are expensive to build or adding lead packages around a chip that is expensive and add weight to the chip. An alternative radiation hardening technique is to utilize a radiation hardened by design library. This library includes digital gates that have been hardened …

Frequency Domain Processing Based Chaos Communication For Cognitive Radio, Daniel Y. Sundersingh

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Chaotic systems are deterministic non-linear dynamical systems which have intrinsic properties such as: irregularity, aperiodicity, and are impossible to predict over long periods of time. Cognitive radio on the other hand, has emerged recently as a powerful means to tackle the spectrum congestion problem. The goal of this thesis is to combine the benefits of the chaos communication system with the cognitive radio to create a robust, highly secure, flexible chaotic cognitive radio system. We first begin with a short survey of chaotic communication and cognitive radio technology. Then we compare chaotic waveforms to other conventional PN sequences and show …