Physical Sciences and Mathematics Commons^™

Along-Shelf Connectivity And Circumpolar Gene Flow In Antarctic Silverfish (Pleuragramma Antarctica), Jilda Alicia Caccavo, Chiara Papetti, Maj Wetjen, Rainer Knust, Julian R. Ashford, Lorenzo Zane

OES Faculty Publications

The Antarctic silverfish (Pleuragramma antarctica) is a critically important forage species with a circumpolar distribution and is unique among other notothenioid species for its wholly pelagic life cycle. Previous studies have provided mixed evidence of population structure over regional and circumpolar scales. The aim of the present study was to test the recent population hypothesis for Antarctic silverfish, which emphasizes the interplay between life history and hydrography in shaping connectivity. A total of 1067 individuals were collected over 25 years from different locations on a circumpolar scale. Samples were genotyped at fifteen microsatellites to assess population differentiation and …

Challenges With Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato, B. Wang

Physics Faculty Publications

We survey the current phenomenological status of semi-inclusive deeply inelastic scattering at moderate hard scales and in the limit of very large transverse momentum. As the transverse momentum becomes comparable to or larger than the overall hard scale, the differential cross sections should be calculable with fixed order perturbative QCD (pQCD) methods, while small transverse momentum (transverse-momentum-dependent factorization) approximations should eventually break down. We find large disagreement between HERMES and COMPASS data and fixed order calculations done with modern parton densities, even in regions of kinematics where such calculations should be expected to be very accurate. Possible interpretations are suggested.

Determination Of The Magnetic Field Dependence Of The Surface Resistance Of Superconductors From Cavity Tests, J. R. Delayen, H. Park, S. Su. De Silva, G. Ciovati, Z. Li

Physics Faculty Publications

We present a general method to derive the magnetic field dependence of the surface resistance of superconductors from the Q-curves obtained during the cryogenic tests of cavities. The results are applied to coaxial half-wave cavities, TM-like “elliptical” accelerating cavities, and cavities of more complicated geometries.

Question 1: Clock Variation; Question 2: Recycling Coffee Pods, Larry Weinstein

Physics Faculty Publications

The article presents questions and answers regarding the impact of gravity on pendulum clocks and the recycling of coffee pods.

Investigation Of Electrolytic Flocculation For Microalga Scenedesmus Sp Using Aluminum And Graphite Electrodes, Shihong Liu, Husam A. Abu Hajar, Guy Riefler, Ben J. Stuart

Civil & Environmental Engineering Faculty Publications

Electrolytic flocculation using non-sacrificial electrodes with flocculants added was studied on harvesting Scenedesmus sp. In order to optimize the operating conditions of the electrolytic flocculation process and to quantify the amount of flocculants added, aluminum electrodes were first used in the process. It was found that under optimal conditions, the microalgae removal efficiency using aluminum electrodes could reach 98.5%, while 34.2 mg L^-1 of aluminum ions were released during the process. Different metal electrodes were also studied, but high microalgae removal efficiency was witnessed only using aluminum electrodes, indicating the influence of the aluminum ion in flocculation. When non-sacrificial …

Improved Gas Sensing Performance Of Ald Azo 3-D Coated Zno Nanorods, P. Lin, X. Chen, K. Zhang, H. Baumgart

Electrical & Computer Engineering Faculty Publications

This paper reports an enhancement on the sensing performance of ZnO nanorod ethanol sensors with a new approach by utilizing nested coatings of Aluminum doped ZnO (AZO) thin films by Atomic Layer Deposition (ALD) technology. ZnO nanorods were grown by the hydrothermal method with the ZnO seed layer synthesized on Silicon wafers by ALD. To enhance the sensing performance of ZnO nanorod ethanol sensors, multiple coated AZO thin film 3-D coatings were deposited on the surface of the intrinsic ZnO nanorods by ALD.To investigate the sensing performance of the ZnO nanorods sensor for the detection of ethanol vapor, a gas …

Carnivorous Pitcher Plants Eat A Diet Of Certain Spiders, Regardless Of What's On The Menu, Marc A. Milne, Deborah A. Waller

Biological Sciences Faculty Publications

The purple pitcher plant, Sarracenia purpurea, is a low-lying carnivorous plant that uses pitcher-shaped leaves to catch arthropod prey for nutrition. Spiders make up a significant portion of these prey. To determine the tendency of specific spider taxa to be captured by the plant, we compared the composition (by taxonomic family) of three spider assemblages: those captured by the plant, those residing on or over the plant, and those found nearby in the local environment. Although there were some broad similarities within the three spider assemblages, significant differences existed when specific families and guilds were considered. While some families …

A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus

OES Faculty Publications

The mean state and variability of the tropical Pacificis influenced by the depth of the thermocline. During the Last Glacial Maximum (~21,000 years ago), the zonal sea surface temperature gradient across the equatorial Pacific was reduced and productivity was generally lower than modern. To understand the thermocline depth’s role in determining the Last Glacial Maximum tropical mean state, we reconstruct the upper ocean δ¹⁸O profile from multiple species of planktic foraminifera. We synthesize existing records of surface and subsurface dwelling foraminifera to reconstruct the vertical δ¹⁸O gradient throughout the eastern equatorial Pacific. We find the thermocline …

Investigation On The Rons And Bactericidal Effects Induced By He + O2 Cold Plasma Jets: In Open Air And In An Airtight Chamber, Han Xu, Dingxin Liu, Weitao Wang, Zhijie Liu, Li Guo, Mingzhe Rong, Michael G. Kong

Bioelectrics Publications

He + O₂ plasma jets in open air and in an airtight chamber are comparatively studied, with respect to their production of gaseous/aqueous reactive species and their antibacterial effects. Under the same discharge power, the plasma jet in open air has higher densities of gaseous reactive species and a higher concentration of aqueous H₂O₂ but lower concentrations of aqueous OH and O₂^-. In addition, the increase in the O₂ ratio in He in both plasma jets causes a linear decrease in the population of gaseous reactive species, except for O(3p⁵P) …

Solutions For Fermi Questions, November 2018: Question 1: Kale; Question 2: Hurricane Angular Momentum, Larry Weinstein

Physics Faculty Publications

The article presents questions and answers related to physics estimations including the amount of kale needed to provide the right amount of calories in a year, and the angular momentum of Hurricane Florence.

Search For A Dark Photon In Electroproduced E + E − Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, G. Kalicy, H. Szumila-Vance, L. B. Weinstein, Heavy Photon Search Collaboration

Physics Faculty Publications

The Heavy Photon Search experiment took its first data in a 2015 engineering run using a 1.056 GeV, 50 nA electron beam provided by CEBAF at the Thomas Jefferson National Accelerator Facility, searching for a prompt, electroproduced dark photon with a mass between 19 and 81  MeV/c². A search for a resonance in the e⁺e⁻ invariant mass distribution, using 1.7 days (1170  nb⁻¹) of data, showed no evidence of dark photon decays above the large QED background, confirming earlier searches and demonstrating the full functionality of the experiment. Upper limits on the square …

Synthesis And Biological Evaluation Of Phaeosphaeride A Derivatives As Antitumor Agents, Victoria Abzianidze, Petr Beltyukov, Sofya Zakharenkova, Natalia Moiseeva, Jennifer Mejia, Alvin Holder, Yuri Trishin, Alexander Berestetskiy, Victor Kuznetsov

Chemistry & Biochemistry Faculty Publications

New derivatives of phaeosphaeride A (PPA) were synthesized and characterized. Anti-tumor activity studies were carried out on the HCT-116, PC3, MCF-7, A549, К562, NCI-Н929, Jurkat, THP-1, RPMI8228 tumor cell lines, and on the HEF cell line. All of the compounds synthesized were found to have better efficacy than PPA towards the tumor cell lines mentioned. Compound 6 was potent against six cancer cell lines, HCT-116, PC-3, K562, NCI-H929, Jurkat, and RPMI8226, showing a 47, 13.5, 16, 4, 1.5, and 7-fold increase in anticancer activity comparative to those of etoposide, respectively. Compound 1 possessed selectivity toward the NCI-H929 cell line (IC …

Question 1: Kale; Question 2: Hurricane Angular Momentum, Larry Weinstein

Physics Faculty Publications

A quiz concerning the amount of kale needed to provide calories for a person in a year and the angular momentum of Hurricane Florence when it made landfall.

Mulholland Leading Volunteer Effort To "Measure The Muck" In Chesapeake Bay Oct. 27, News @ Odu

News Items

No abstract provided.

The 'New Normal' Of Flooding In Portsmouth, Virginia: Perspectives, Experiences, And Adaptive Responses Of Residents And Business Owners In Low To Moderate-Income Communities, Donta Council, Michelle Covi, Wie Yusuf, Joshua Behr, Makayla Brown, Old Dominion University Resilience Collaborative, Virginia Sea Grant

Presentations, Lectures, Posters, Reports

[First three paragraphs from the Summary]

This project is a part of a broader initiative - the Resilience Adaptation Feasibility Tool (RAFT) - that addresses the daunting challenges coastal communities are facing related to sea level rise and climate change (more information about RAFT is available here: https://ien.virginia.edu/raft).

This aim of this project was to investigate how residents and business owners in low-to-moderate income communities in Portsmouth, Virginia cope with flooding, and to assess implications for how the local government can better engage with residents to better meet their information needs so they can be more resilient to flooding. The …

October Science Pub: Using Technology To Map The Effects Of Sea Level Rise, Amy Matzke-Fawcett

News Items

No abstract provided.

Circulation, Vol. 24, No. 1, Center For Coastal Physical Oceanography, Old Dominion University, Larry Atkinson

CCPO Circulation

Fall 2018 issue of CCPO Circulation featuring article "The Past, Present and Future of CCPO" by Dr. Larry Atkinson.

Interface Model Of Pem Fuel Cell Membrane Steady-Dtate Behavior, Russell L. Edwards, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

Modeling works which simulate the proton-exchange membrane fuel cell with the computational fluid dynamics approach involve the simultaneous solution of multiple, interconnected physics equations for fluid flows, heat transport, electrochemical reactions, and both protonic and electronic conduction. Modeling efforts vary by how they treat the physics within and adjacent to the membrane-electrode assembly (MEA). Certain approaches treat the MEA not as part of the computational domain, but rather an interface connecting the anode and cathode computational domains. These approaches may lack the ability to consistently model catalyst layer losses and MEA ohmic resistance. This work presents an upgraded interface formulation …

No2- And No3- Enhance Cold Atmospheric Plasma Induced Cancer Cell Death By Generation Of Onoo-, Dehui Xu, Qingjie Cui, Yujing Xu, Zhijie Liu, Zeyu Chen, Wenjie Xia, Hao Zhang, Dingxin Liu, Hailan Chen, Michael G. Kong

Bioelectrics Publications

Cold atmospheric plasma (CAP) is a rapidly developed technology that has been widely applied in biomedicine especially in cancer treatment. Due to the generation of various active species in plasma, CAP could induce various tumor cells death and showed a promising potential in cancer therapy. To enhance the biological effects of gas plasma, changing the discharging parameters is the most commonly used method, yet increasing discharging power will lead to a higher possibility of simultaneously damage surrounding tissues. In this study, by adding nontoxic concentration of additional nitrite and nitrate in the medium, we found that anti-tumor effect of CAP …

Current-Driven Production Of Vortex-Antivortex Pairs In Planar Josephson Junction Arrays And Phase Cracks In Long-Range Order, Francisco Estellés-Duart, Miguel Ortuño, Andrés M. Somoza, Valerii M. Vinokur, Alex Gurevich

Physics Faculty Publications

Proliferation of topological defects like vortices and dislocations plays a key role in the physics of systems with long-range order, particularly, superconductivity and superfluidity in thin films, plasticity of solids, and melting of atomic monolayers. Topological defects are characterized by their topological charge reflecting fundamental symmetries and conservation laws of the system. Conservation of topological charge manifests itself in extreme stability of static topological defects because destruction of a single defect requires overcoming a huge energy barrier proportional to the system size. However, the stability of driven topological defects remains largely unexplored. Here we address this issue and investigate numerically …

Solutions For Fermi Questions, October 2018: Question 1: Automobile Air Conditioning; Question 2: Falling Leaves, Larry Weinstein

Physics Faculty Publications

The article presents questions and answers related to topics including automobile air conditioning and falling leaves.

Measurement Of Unpolarized And Polarized Cross Sections For Deeply Virtual Compton Scattering On The Proton At Jefferson Laboratory With Clas, N. Hirlinger Saylor, K. P. Adhikari, M. J. Amaryan, S. Bültmann, G. Gavalian, M. Khachatryan, A. Klein, S E. Kuhn, Y. Prok, J. Zhang, Z. W. Zhao, Clas Collaboration

Physics Faculty Publications

This paper reports the measurement of polarized and unpolarized cross sections for the ep → e 'p' γ reaction, which is composed of deeply virtual Compton scattering (DVCS) and Bethe-Heitler (BH) processes, at an electron beam energy of 5.88 GeV at the Thomas Jefferson National Accelerator Facility using the Large Acceptance Spectrometer CLAS. The unpolarized cross sections and polarized cross section differences have been measured over broad kinematics, 0.10 2 < 4.8 GeV²,and 0.09 < −t< 2.00 GeV². The results are found to be consistent with previous CLAS data, and these new data are discussed in the framework of the generalized parton distribution …

Question 1: Automobile Air Conditioning; Question 2: Falling Leaves, Larry Weinstein

Physics Faculty Publications

The article focuses on the questions on physics regarding automobile air conditioning and calculating the number of leaves to fall in U.S.

Short Range Correlations And The Isospin Dependence Of Nuclear Correlation Functions, R. Cruz-Torres, A. Schmidt, G. A. Miller, L. B. Weinstein, N. Barnea, R. Weiss, E. Piasetzky, O. Hen

Physics Faculty Publications

Pair densities and associated correlation functions provide a critical tool for introducing many-body correlations into a wide-range of effective theories. Ab initio calculations show that two-nucleon pairdensities exhibit strong spin and isospin dependence. However, such calculations are not available for all nuclei of current interest. We therefore provide a simple model, which involves combining the short and long separation distance behavior using a single blending function, to accurately describe the two nucleon correlations inherent in existing ab initio calculations. We show that the salient features of the correlation function arise from the features of the two-body short-range nuclear interaction, and …

Event Engineering Studies For Heavy Flavor Production And Hadronization In High Multiplicity Hadron-Hadron And Hadron-Nucleus Collisions, Yan-Qing Ma, Prithwish Tribedy, Raju Venugopalan, Kazuhiro Watanabe

Physics Faculty Publications

Heavy flavor measurements in high multiplicity proton-proton and proton-nucleus collisions at collider energies enable unique insights into their production and hadronization mechanism because experimental and theoretical uncertainties cancel in ratios of their cross sections relative to minimum bias events. We explore such event engineering using the color glass condensate (CGC) effective field theory to compute short-distance charmonium cross sections. The CGC is combined with heavy-quark fragmentation functions to compute D-meson cross sections; for the J/ψ, hadronization is described employing nonrelativistic QCD (NRQCD) and an improved color evaporation model. Excellent agreement is found between the CGC computations and the LHC heavy …

Local Chiral Interactions, The Tritium Gamow-Teller Matrix Element, And The Three-Nucleon Contact Term, A. Baroni, R. Schiavilla, L. E. Marcucci, L. Girlanda, A. Kievsky, A. Lovato, S. Pastore, M. Piarulli, Steven C. Pieper, M. Viviani, R. B. Wiringa

Physics Faculty Publications

The Gamow-Teller (GT) matrix element contributing to tritium β decay is calculated with trinucleon wave functions obtained from hyperspherical-harmonics solutions of the Schrödinger equation with the chiral two- and three-nucleon interactions including Δ intermediate states that have recently been constructed in configuration space. Predictions up to next-to-next-to-next-to-leading order (N3LO) in the chiral expansion of the axial current (with Δ's) overestimate the empirical value by 1–4%. By exploiting the relation between the low-energy constant (LEC) in the contact three-nucleon interaction and two-body axial current, we provide new determinations of the LECs cD and cE that characterize this interaction by fitting the …

Beam-Target Helicity Asymmetry E In K 0 Λ And K 0 Σ 0 Photoproduction On The Neutron, D. H. Ho, R. A.. Schumacher, A. D' Angelo, A. Deur, J. Fleming, C. Hanretty, K. P. Adhikari, D. Adikaram, M. Khachatryan, A. Klein, M. Meyer, L. B. Weinstein, The Class Collaboration

Physics Faculty Publications

We report the first measurements of the E beam-target helicity asymmetry for the →γ→n→K⁰Λ and K⁰Σ⁰ channels in the energy range 1.70 ≤ W ≤ 2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees is used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin I=0 and I …

The Effects Of Metacognitive Training On Algebra Students’ Calibration Accuracy, Achievement, And Mathematical Literacy, Deana J. Ford

Teaching & Learning Theses & Dissertations

This dissertation describes an empirical study that investigated how metacognitive training influenced lower achieving Algebra students’ calibration accuracy, achievement, and development of mathematics literacy. Multiple methods were used to collect and analyze the data. Close analysis of students’ work and classroom observations revealed that students that were exposed to the metacognitive training had significantly higher prediction accuracy and made gains in their understanding of the mathematics word problems than did students who did not receive the metacognitive training. Overall, however, both the intervention and comparison groups improved in their academic performance and became more mathematically literate and accurate in their …

Electrostatic Design And Conditioning Of A Triple Point Junction Shield For A −200 Kv Dc High Voltage Photogun, G. Palacios-Serrano, F. Hannon, C. Hernandez-Garcia, M. Poelker, H. Baumgart

Electrical & Computer Engineering Faculty Publications

Nuclear physics experiments performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at the Jefferson Lab require a DC high voltage photogun to generate polarized electron beams from GaAs photocathodes. The photogun uses a tapered ceramic insulator that extends into the vacuum chamber and mechanically holds the cathode electrode. Increasing the operating voltage from nominal −130 kV to −200 kV will provide lower beam emittance, better transmission through injector apertures, and improved photocathode lifetime. This desire to increase the photogun operating voltage led to the design of a triple-point-junction shield electrode which minimizes the electric field at the delicate insulator-metal-vacuum …

Wireless Sensor Networks For Smart Communications, Mu Zhou, Qilian Liang, Hongyi Wu, Weixiao Meng, Kunjie Xu

Electrical & Computer Engineering Faculty Publications

(First paragraph) In the first edition of the special issue titled “Wireless Sensor Networks for Smart Communications”, a total of 22 manuscripts were received and 6 of these were accepted. This issue demonstrated that network congestion, user mobility, and adjacent spectrum interference are the main reasons for the degradation ofcommunication quality inWireless Sensor Networks (WSNs).