Physical Sciences and Mathematics Commons^™

19. Zoology, Northeastern State University

Oklahoma Research Day Abstracts

No abstract provided.

Towards Analytical Techniques For Optimizing Knowledge Acquisition, Processing, Propagation, And Use In Cyberinfrastructure, Leonardo Octavio Lerma

Open Access Theses & Dissertations

For many decades, there has been a continuous progress in science and engineering applications.

A large part of this progress comes from the new knowledge that researchers acquire, propagate, and use. This new knowledge has revolutionized many aspects of our life, from driving to communications to shopping.

Somewhat surprisingly, there is one area of human activity which is the least impacted by the modern technological progress: the very processes of acquiring, processing, and propagating information. When we decide where to place sensors, which algorithm to use for processing the data – we rely mostly on our own intuition and on …

Does Low-Level Arsenic Exposure Predict Blood Pressure In Children?, Tania Angelica Mayorga

Open Access Theses & Dissertations

Background & Significance: Inorganic arsenic is a heavy metal naturally found in soil and human exposure to this heavy metal causes adverse effects. Exposure risks are particularly high in developing children. Arsenic is mainly found in bedrock. It is also a by-product of smelting, it is used in cement production, and historically is has been found in crop pesticides. Among other ill-effects, arsenic exposure in humans can cause respiratory diseases, peripheral neuropathy and liver fibrosis. In particular arsenic has been shown in many studies to be a contributing factor in the risk for hypertension in adults however no studies have …

Processing And Property Evaluation Of Tungsten-Based Mixed Oxides For Photovoltaics And Optoelectronics, Mirella Vargas

Open Access Theses & Dissertations

Tungsten Oxide (WO3) films and low-dimensional structures have proven to be promising candidates in the fields of photonics and electronics. WO3 is a well-established n-type semiconductor characterized by unique electrochromic behavior, an ideal optical band gap that permits transparency over a wide spectral range, and high chemical integrity. The plethora of diverse properties endow WO3 to be highly effective in applications related to electrochromism, gas sensing, and deriving economical energy. Compared to the bulk films, a materials system involving WO3 and a related species (elements or metal oxides) offer the opportunity to tailor the electrochromic response, and an overall enhancement …

Comparison Of Blood Lead Levels Between Children In An Urban Setting And Children In A Rural Setting, Juan Manuel Alvarez

Open Access Theses & Dissertations

Environmental heavy metal exposure is a public health problem that is of great concern because it is highly toxic for children. The urban setting in downtown El Paso is historically known to be contaminated through various sources of contamination of heavy metals. The goal of this study was to compare whether children in a historically contaminated urban downtown area had significantly increased levels of lead exposure as compared to children in a demographically similar rural area approximately 20 miles north of the urban center, while controlling for gender and age. Cadmium and mercury were also measured for comparison purposes. It …

Lithospheric Structure And Stress Field Orientations In The Northern Libya And East-Central Mediterranean Region, Abdusalam Ali Agail

Open Access Theses & Dissertations

This thesis is a combination of three studies including tomography using surface wave group velocities, stress orientations from focal mechanisms, and receiver functions. The study area covers northern Libya and the east central Mediterranean region. I utilized new data from the Libyan National Seismic Network to better understand the crustal thickness and stress orientation of northern Libya as well as the east central Mediterranean region. In the first study, I conducted surface wave group velocity tomography implementing the Gaussian beam method for obtaining 2-D velocity variations assuming an isotropic model. I constructed surface wave group velocity maps over a range …

Virtual Rapport With Extraverted Agents, Jacqueline Brixey

Open Access Theses & Dissertations

Studies from psychology conclude that "birds of a feather flock together"- or, in other words, people tend to seek companionship with those who have a similar personality to their own. Researchers in the fields of Linguistics and Psychology have found numerous markers that differentiate the dialogue of extroverts from that of introverts. Recent work in Human Computer Interaction has sought to understand the nature of creating and maintaining rapport between humans and Embodied Conversational Agents (ECAs).

Seeking an interdisciplinary approach that combines knowledge from HCI, Linguistics, and Psychology, I sought to establish whether introverted users report the highest level of …

Molecular Dynamics Study On Defect Reduction Strategies Towards The Fabrication Of High Performance Cd1-Xznxte/Cds Solar Cells, Jose Juan Chavez

Open Access Theses & Dissertations

Cadmium Telluride is a material widely used in terrestrial thin film photovoltaic applications due to its nearly ideal band gap (~1.5 eV) and high absorption coefficient. Due to its low manufacturing cost, this technology has the potential to become a significant energy resource if higher energy conversion efficiencies are achieved. However, the module efficiencies (~14%) are still far from the theoretical maximum (~30%) for this material in a single junction configuration. The reason behind this low performance is attributed to the high number of defects that are present within the device materials. The physics behind the formation mechanisms of these …

Novel Endohedral Derivatives Of Sc3n@C2n (N = 34, 40) And Unique Tether Controlled Bis-Functionalization Of Fullerenes, Maira Raquel Ceron Hernandez

Open Access Theses & Dissertations

Since the discovery of fullerenes in 1985, their exohedral functionalization has been necessary to increase their solubility and explore their properties and potential applications in materials science and medicinal chemistry. This Thesis provides a short overview of the importance of electronic, size and shape complementarity in determining the structures of specific endohedral fullerene compounds. This is followed by a description of a new method for the separation of scandium nitride endohedral fullerenes Sc3N@C2n (n = 34, 39 and 40), and their monofunctionalization.

We also present the regioselective synThesis of easily isolable bis-derivatives of C60, C70, and M3N@Ih-C80 (M = Sc, …

Effect Of Plastic Deformation Anisotropies On Shock-Induced Phase Transitions In Metallic Single Crystals, Punam Ghimire

Open Access Theses & Dissertations

Most metals and alloys undergo plastic deformation at shear stresses and/or pressures in the Kbars regime. On the other hand, typical pressure-induced structural transitions, take place at much higher pressures, in the tens of GPa range. Surprisingly, there has not been to date, a systematic study on the role plastic deformation plays on the dynamics of defect-mediated phase transformations. The main purpose of this work was to investigate via atomistic simulations, the contribution of pre-existing defect densities on the kinetics of structural transformations under dynamic loading. We have carried out molecular dynamics simulations - including large-scale non-equilibrium molecular dynamics (NEMD), …

Exploratory Study Of Seasonal Indoor Bioaerosols And The Associated Health Outcomes In Low-Income Communities In El Paso, Texas, 2014, Eric Martinez

Open Access Theses & Dissertations

Introduction: Structural degradation, moisture levels, and building failures can influence poor indoor air quality and create a good environment for bioaerosols. People spend much of their time indoors and can potentially be exposed to these bioaerosols. Several studies have correlated exposures to high concentrations of bioaerosols to various health problems, severe allergies, asthma, or other respiratory illness. Objectives: The objectives of this study are to describe bioaerosol concentrations, meteorological factors, and health outcomes during the summer and fall seasons; characterize bioaerosols (bacteria and fungi) collected in low-income communities; compare bioaerosol concentrations by season; compare meteorological factors to bioaerosol concentrations by …

On The Path To Multi-Electron Redox Chemistry With Bimetallic Systems, Nathalie Metta

Open Access Theses & Dissertations

The following study is presented in two sections, in the first, a novel digold (II) complex with semi-bridging chlorides supported by two bulky formamidinates was synthesized for the purpose of studying late-transition metal multi-electron redox chemistry. Electrochemical analysis shows one non-reversible reduction. Although the electrochemistry of this complex is restricted, the compound shows interesting electronic properties. The crystal structure reveals a geometry distortion of the Au2ï?­-Cl2 core. The coupling of an unoccupied orbital and an occupied orbital through a vibrational mode, causes a distortion in the geometry of the molecule lowering the D2h symmetry to C2h. This is an example …

Prospective Secondary Science Teachers' Argumentation Skills And The Interaction Of These Skills With Their Conceptual Knowledge, Ömer Acar, Bruce R. Patton, Arthur L. White

Australian Journal of Teacher Education

This study investigated if prospective secondary science teachers enhance their argumentation skills and the interaction of the change in their argumentation skills with their conceptual knowledge during an argumentation-based guided inquiry course. 37 prospective secondary science teachers constituted the study sample. They were grouped according to whether or not they had a misconception about understanding of balanced forces at the beginning of the course. They performed oral and written argumentation tasks during the course. Their written argumentation tasks were assessed four times during the course for balanced forces and sinking and floating behaviour of objects. Results indicated that prospective secondary …

Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering, E. Seder, A. Biselli, S. Bültmann, A. Klein, S. E. Kuhn, Y. Prok, Clas Collaboration

Physics Faculty Publications

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for e p → e'p'ɣ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q², x_B, t, and ɸ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into …

Measurements Of Ep → E'Π+N At 1.6 < W <2.0 Gev And Extraction Of Nucleon Resonance Electrocouplings At Clas, The Clas Collaboration, K. Park, K. P. Adhikari, M. J. Amaryan, L. El Fassi, Y. Prok, L. B. Weinstein

Physics Faculty Publications

Differential cross sections of the exclusive process ep -> e 'π⁺n were measured with good precision in the range of the photon virtuality Q² = 1.8-4.5 GeV² and the invariant mass range of the π⁺n final state W = 1.6-2.0 GeV using the Continuous Electron Beam Accelerator Facility Large Acceptance Spectrometer. Data were collected with nearly complete coverage in the azimuthal and polar angles of the n π⁺center-of-mass system. More than 37 000 cross-section points were measured. The contributions of the isospin I = ½ resonances N(1675) 5/2^-, N(1680) 5/2 …

Direct Observation Of Quark-Hadron Duality In The Free Neutron F2 Structure Function, I. Niculescu, G. Niculescu, W. Melnitchouk, J. Arrington, M. E. Christy, S. Kuhn

Physics Faculty Publications

Using the recently published data from the BONuS(Barely Off-shell Nucleon Structure) experiment at Jefferson Lab, which utilized a spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F₂ structure function. The data are used to reconstruct the lowest few (N = 2, 4, and 6) moments of F₂ in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark-hadron duality holds locally …

Precise Determination Of The Deuteron Spin Structure At Low To Moderate Q² With Clas And Extraction Of The Neutron Contribution, The Clas Collaboration, N. Guler, S E. Kuhn, Y. Prok, K. P. Adhikari, D. Adikaram, M. J. Amaryan, L. El Fassi, C. E. Hyde, A. Klein, L. B. Weinstein, Z. W. Zhao

Physics Faculty Publications

We present the final results for the deuteron spin structure functions obtained from the full data set collected in 2000–2001 with Jefferson Lab's continuous electron beam accelerator facility (CEBAF) using the CEBAF large acceptance spectrometer (CLAS). Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.8 GeV were scattered from deuteron (¹⁵ND₃ ) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double-spin asymmetry, the virtual photon absorption asymmetry A^d₁ and the polarized structure function g^d₁ were extracted over a wide kinematic range (0.05GeV² < Q2 < 5GeV² and 0.9 …

Measurement Of The Emc Effect In The Deuteron, K. A. Griffioen, J. Arrington, M. E. Christy, R. Ent, N. Kalantarians, C. E. Keppel, S E. Kuhn

Physics Faculty Publications

We determined the structure function ratio R^d_EMC=F^d₂/(Fⁿ₂+F^p₂) from recently published Fⁿ₂/F^d₂ data taken by the BONuS experiment using CLAS at Jefferson Lab. This ratio deviates from unity, with a slope dR^d_EMC/dx=−0.10 ± 0.05 in the range of Bjorken x from 0.35 to 0.7, for invariant mass W>1.4 GeV and Q²>1 GeV² . The observed EMC effect for these kinematics is consistent with conventional nuclear physics models that include off-shell corrections, as well as with empirical analyses …

Design Of Dressed Crab Cavities For The Hl-Lhc Upgrade, C. Zanoni, K. Artoos, S. Atieh, I. Aviles-Santillana, S. Belomestnykh, I. Ben-Zvi, J.P. Brachet, G. Burt, R. Calaga, O. Captina, S. U. De Silva, J. R. Delayen, A. May, K. Marinov, R. Olave, H. Park, N. Templeton

Physics Faculty Publications

The HL-LHC upgrade relies on a set of RF crab cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final geometry is provided along with an insight in the mechanical and thermal analyses performed to validate the …

Performance Evaluation Of Hl-Lhc Crab Cavity Prototypes In A Cern Vertical Test Cryostat, K. G. Hernández-Chahín, A. Macpherson, C. Jarrige, M. Navarro-Tapia, R. Torres Sánchez, G. Burt, A. Tutte, S. U. De Silva

Physics Faculty Publications

Three proof-of-principle compact crab cavity designs have been fabricated in bulk niobium and cold tested at their home labs, as a first validation step towards the High Luminosity LHC project. As a cross check, all three bare cavities have been retested at CERN, in order to cross check their performance, and cross-calibrate the CERN SRF cold test facilities. While achievable transverse deflecting voltage is the key performance indicator, secondary performance aspects derived from multiple cavity monitoring systems are also discussed. Temperature mapping profiles, quench detection, material properties, and trapped magnetic flux effects have been assessed, and the influence on performance …

Progress On A Compact Accelerator Design For A Compton Light Source, K. Deitrick, J. R. Delayen, B.R.P. Gamage, Geoffrey A. Krafft, T. Satogata

Physics Faculty Publications

A compact Compton light source using an electron linear accelerator is in design at the Center for Accelerator Science at Old Dominion University and Jefferson Lab. We report on the current design, including beam properties through the entire system based on a full end-to-end simulation, compare current specifications to design goals, and target areas for improvement.

Beam Dynamics Studies Of 499 Mhz Superconducting Rf-Dipole Deflecting Cavity System, S. U. De Silva, K. E. Deitrick, H. Park, J. R. Delayen

Physics Faculty Publications

A 499 MHz deflecting cavity has been designed as a three-way beam spreader to separate an electron beam into 3 beams. The rf tests carried out on the superconducting rf-dipole cavity have demonstrated that a transverse voltage of 4.2 MV can be achieved with a single cavity. This paper discusses the beam dynamics on a deflecting structure operating in continuous-wave mode with a relativistic beam. The study includes the analysis on emittance growth, energy spread, and change in bunch size including effects due to field non-uniformities.

Peppo: Using A Polarized Electron Beam To Produce Polarized Positrons, A. Adeyemi, G.L Gueye, P.A. Adderly, M. L. Stutzman, M. M. Ali, H. Areti, J. F. Benesch, L. S. Cardman, J. Clark, S. Covert, S. Golge, C. Hyde

Physics Faculty Publications

An experiment demonstrating a new method for producing polarized positrons has been performed at the CEBAF accelerator at Jefferson Laboratory. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e⁺/e⁻ pairs originating from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a 1.0 mm tungsten pair-production target. This paper describes preliminary results of measurements using an 8.2 MeV/c electron beam with polarization 84% to generate positrons in the range of 3.1 to 6.2 MeV/c with polarization as high as ∼80%.

Single And Double Spin Asymmetries For Deeply Virtual Compton Scattering Measured With Clas And A Longitudinally Polarized Proton Target, S. Pisano, A. Biselli, S. Niccolai, K. Adhikari, D. Adikaram, M. J. Amaryan, S. E. Kuhn, L. B. Weinstein, Z. W. Zhao, Clas Collaboration

Physics Faculty Publications

Single-beam, single-target, and double spin asymmetries for hard exclusive electroproduction of a photon on the proton ^→e^→p~ → e'p'γ are presented. The data were taken at Jefferson Lab using the CEBAF large acceptance spectrometer and a longitudinally polarized ¹⁴NH₃ target. The three asymmetries were measured in 165 four-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of generalized parton distributions. The measurement of three DVCS spin observables …

Ua12/2/2 2015 Talisman: Resurgence, Wku Student Affairs

WKU Archives Records

2015 Talisman yearbook.

• Osborne Sam. Into the Woods – Big To-Do Music & Arts Festival
• Spalding, Shelley. The Outliers – Greeks
• Badjie, Haddy. The Right to Live – Racism
• Gibson, Helen. Net Worth – Soccer
• Greer, John. Sustaining Seasons – Sustainability
• Wegert, Sally. Bloom – Eva Ross
• Cislo, Everett. Harvest – Hemp
• Kolb, William. Preserve – John All
• Voorhees, Jessica. Making Strides – Track & Field
• Greer, John. The Science Guy – Bill Nye
• Cole, Tanner. Lip Service – Rocky Horror Picture Show
• Belknap, Abby. Race to the Senate
• Gibson, Helen. Game of Loans – Student Financial Aid
• Belknap, Abby. …

Temperature Mapping Of Nitrogen-Doped Niobium Superconducting Radiofrequency Cavities, Junki Makita, Gianluigi Ciovati, Pashupati Dhakal

Physics Faculty Publications

It was recently shown that diffusing nitrogen on the inner surface of superconducting radiofrequency (SRF) cavities at high temperature can improve the quality factor of the niobium cavity. However, a reduction of the quench field is also typically found. To better understand the location of rf losses and quench, we used a thermometry system to map the temperature of the outer surface of ingot Nb cavities after nitrogen doping and electropolishing. Surface temperature of the cavities was recorded while increasing the rf power and also during the quenching. The results of thermal mapping showed no precursor heating on the cavities …

Minimally Nonlocal Nucleon-Nucleon Potentials With Chiral Two-Pion Exchange Including Δ Resonances, M. Piarulli, L. Girlanda, Rocco Schiavilla, R. Navarro Pérez, J. E. Amaro, E. Ruiz Arriola

Physics Faculty Publications

We construct a coordinate-space chiral potential, including Δ -isobar intermediate states in its two-pion-exchange component up to order Q³ (Q denotes generically the low momentum scale). The contact interactions entering at next-to-leading and next-to-next-to-next-to-leading orders (Q² and Q⁴ , respectively) are rearranged by Fierz transformations to yield terms at most quadratic in the relative momentum operator of the two nucleons. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database, consisting of 2309 pp and 2982 np data (including, respectively, 148 and 218 normalizations) in the laboratory-energy range 0–300 MeV. For the total …

Maximum Screening Fields Of Superconducting Multilayer Structures, Alex Gurevich

Physics Faculty Publications

It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields H_sof both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness ~0.1μm at the Nb surface could increase H_s similar or equal to 240 mT of a clean Nb up to H_s similar or equal to 290 mT. Optimized multilayers of Nb₃Sn, NbN, some of the iron pnictides, or alloyed …

Probing Dynamics And Pinning Of Single Vortices In Superconductors At Nanometer Scales, L. Embon, Y. Anahory, A Suhov, D. Halbertal, J. Cuppens, A. Yakovenko, A. Uri, Y. Myasoedov, M. L. Rappaport, M. E. Huber, A. Gurevich, E. Zeldov

Physics Faculty Publications

The dynamics of quantized magnetic vortices and their pinning by materials defects determine electromagnetic properties of superconductors, particularly their ability to carry non-dissipative currents. Despite recent advances in the understanding of the complex physics of vortex matter, the behavior of vortices driven by current through a multi-scale potential of the actual materials defects is still not well understood, mostly due to the scarcity of appropriate experimental tools capable of tracing vortex trajectories on nanometer scales. Using a novel scanning superconducting quantum interference microscope we report here an investigation of controlled dynamics of vortices in lead films with sub-Angstrom spatial resolution …

Isolation Of Flow And Nonflow Correlations By Two And Four Particle Cumulant Measurements Of Azimuthal Harmonics In √Sɴɴ = Gev Au+Au Collisions, N. M. Abdelwahab, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, S. Bültmann

Physics Faculty Publications

A data-driven method was applied to Au+Au collisions at √Sɴɴ = 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance Δ η-dependent and Δ η-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a Δ η-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity | η | < 1. In 20-30% central Au+Au collisions, the relative flow fluctuation was found to be 34% ± 2%(stat.) ± 3%(sys.) for particles with transverse momentum p_T less than 2 GeV/c. The Δ η-dependent part, attributed to nonflow correlations, is found to be 5% ± 2%(sys.) relative to the flow of the …