Search Results

open access

The Internet and College Students' Motivation to Vote

Description: This article investigates the impact of the political information available on-line on college students’ motivation to vote. The results illustrate that not only politicians, but educators should be cognizant of this civic engagement process. Schools and teachers of all levels are one the front lines of the battle to create a more informed, more involved citizenry; higher education has a strong influence on motivation to vote.
Date: March 1, 2004
Creator: White, Amy E. & King, Kimi L.
Partner: UNT College of Arts and Sciences
open access

The Impact of Mental Aerobics Training on Older Adults

Description: This article investigates the impact of mental aerobics on older adults. Findings support the conclusion that MA can be an effective intervention in improving older adults’ affectivity, everyday task self-efficacy, and self-rated health.
Date: May 1, 2015
Creator: Hayslip, Bert; Paggi, Kay & Caballero, Daniela
Partner: UNT College of Arts and Sciences
open access

Exploratory User Research for Computational Resource for South Asian Languages

Description: Report for the project, Exploratory User Research for CoRSAL, which was an exploratory ethnographic study to generate a foundational understanding of how different user groups might use a planned language archive for South Asian languages. Their research project was to be used by the CoRSAL team to help plan the design of CoRSAL’s infrastructure, and laid the groundwork for further studies that will take a deeper look at issues surrounding the design and use of the planned language archive.
Date: December 7, 2016
Creator: Al Smadi, Duha; Barnes, Sebastian; Blair, Molly; Chong, Miyoung; Cole-Jett, Robin; Davis, Aaron et al.
Partner: UNT College of Arts and Sciences
open access

Terrestrial herpetofauna of Limnos and Agios Efstratios (Northern Aegean, Greece), including new species records for Malpolon insignitus (Geoffroy Saint-Hilaire, 1827) and Pelobates syriacus Boettger, 1889

Description: This article presents herpetofaunal observations from Limnos and Agios Efstratios, two Asia Minor continental shelf islands in the Aegean Sea. Comprehensive surveys over 88 days in total on Limnos, over a period of nine years, consisted mainly of visual encounter surveys and road cruised observations, revealed the presence of three species of amphibians and twelve species of reptiles, including two new species records for the island (Malpolon insignitus and Pelobates syriacus). The results of these surveys provide a clearer understanding of the extant herpetofauna on Limnos and Agios Efstratios and offer discussion on natural history, possible erroneous historical records and preliminary ecological understanding of the herpetofaunal assemblages residing on these islands.
Date: October 25, 2016
Creator: Strachinis, Ilias & Roussos, Stephanos Antonios
Partner: UNT College of Arts and Sciences
open access

An Exploratory Flow Reactor Study of Hydrogen Sulfide Oxidation at 30–100 Bar

Description: Article exploring experiments on hydrogen sulfide oxidation that were conducted in O₂/N₂ at high pressure (30 and 100 bar) under oxidizing and stoichiometric conditions.
Date: November 9, 2016
Creator: Song, Yu; Hashemi, Hamid; Christensen, Jakob Munkholt; Zou, Chun; Haynes, Brian S.; Marshall, Paul et al.
Partner: UNT College of Arts and Sciences
open access

Experimental and Kinetic Modeling Study of Acetylene Oxidation at High Pressure

Description: Article describing a detailed chemical kinetic model for oxidation of acetylene at intermediate temperatures and high pressure that was developed and evaluated experimentally.
Date: August 29, 2016
Creator: Lopez, Jorge Gimenez; Rasmussen, Christian Lund; Hashemi, Hamid; Alzueta, María U.; Gao, Yide; Marshall, Paul et al.
Partner: UNT College of Arts and Sciences
open access

Artificially Structured Boundary for a high purity ion trap or ion source

Description: This article proposes a plasma enclosed by an Artificially Structured Boundary (ASB) as an alternative to existing ion source assemblies. In accelerator applications, many ion sources can have a limited lifetime or frequent service intervals due to sputtering and eventual degradation of the ion source assembly. Ions are accelerated towards the exit canal of positive ion sources, whereas, due to the biasing scheme, electrons or negative ions are accelerated towards the back of the ion source assembly.
Date: March 27, 2014
Creator: Pacheco, J. L.; Ordonez, Carlos A. & Weathers, Duncan L.
Partner: UNT College of Arts and Sciences
open access

Phase space of positron trajectories exiting a charged particle source through a magnetic field point cusp

Description: This article presents a configuration of magnetic fields using properties of cylindrically symmetric permanent magnets as a candidate to produce a high purity charged particle source or trap. Cylindrically symmetric hollow permanent magnets produce magnetic field point cusps on the axis of symmetry. A magnetic field point cusp reflects all particles that lie outside a narrow region of phase space, a region dependent on particle kinetic energies and on the magnetic field intensity.
Date: December 30, 2013
Creator: Kiester, A. S.; Pacheco, J. L.; Ordonez, Carlos A. & Weathers, Duncan L.
Partner: UNT College of Arts and Sciences
open access

Confinement of antiprotons in the electrostatic space charge of positrons in a model of the ALPHA antihydrogen trap

Description: This article details the equilibrium of a positron plasma in a model of the ALPHA apparatus that is computed using a finite-difference method. The positron plasma in the model extends to axial magnetic mirrors in absence of an octupole field. Formation of a three-dimensional electrostatic potential well is found to occur self-consistently. Well depths under various conditions are evaluated. Also, the equilibrium with an antiproton plasma confined in the potential well is computed.
Date: March 17, 2016
Creator: Lane, Ryan A. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Antihydrogen Synthesis Via Magnetobound States of Protonium Within Proton-Positron-Antiproton Plasmas

Description: Article studies the possibility that antihydrogen can be synthesized via three body recombination involving magnetobound protonium through classical trajectory simulation. It has been previously reported that proton antiproton collisions can result in a correlated drift of the particles perpendicular to a magnetic field. While the two particles are in their correlated drift, they are referred to as a magnetobound protonium system. Possible three body recombination resulting in bound state antihydrogen is studied when a magnetobound protonium system encounters a positron.
Date: July 2016
Creator: Hermosillo, M. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Classical trajectory Monte Carlo code for simulating ion beam focusing or defocusing with magnetic elements modeled as current loops or current lines

Description: Article describes a computational tool that can be used for designing magnetic focusing or defocusing systems. A fully three-dimensional classical trajectory Monte Carlo simulation has been developed.
Date: April 19, 2013
Creator: Lane, Ryan A. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Magnetobound positronium and protonium

Description: This article investigates the formation of magnetobound positronium and protonium via classical trajectory simulations of binary point charge interactions in an external magnetic field. The results of computer simulations of the fully three-dimensional trajectories of classical and non-relativistic point charges with the same mass, equal charge magnitude, and opposite sign are reported. The simulations show the formation of magnetobound positronium and protonium. The results yield formation cross sections, which are compared to analytical expressions. Additionally, the results reveal that magnetobound states drift across magnetic field lines.
Date: August 27, 2014
Creator: Correa, J. R. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Electrostatic storage ring with focusing provided by the space charge of an electron plasma

Description: Article describes an electronic storage ring that employs the space charge of an electron plasma for focusing. An advantage of the present concept is that slow ions, or even a stationary ion plasma, can be confined. The concept employs an artificially structured boundary, which is defined at present as one that produces a spatially periodic static field such that the spatial period and range of the field are much smaller than the dimensions of a plasma or charged-particle beam that is confined by the field.
Date: April 19, 2013
Creator: Pacheco, J. L.; Ordonez, Carlos A. & Weathers, Duncan L.
Partner: UNT College of Arts and Sciences
open access

Simulation Of An Antihydrogen Gravity Experiment Utilizing Multiple Apertures

Description: The article presents an analytical model and a Monte Carlo simulation of an antihydrogen gravity experiment that would employ multiple apertures. The model was developed with the primary goal of reducing the experimental run time necessary to determine the direction of free fall acceleration for antimatter in the gravitational field of the Earth. The experiment would confine cryogenic antihydrogen plasma for producing antihydrogen (e.g., by three-body recombination).
Date: April 19, 2013
Creator: Hedlof, R. M. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Giant cross-magnetic-field steps due to binary collisions between pair particles

Description: Article explores giant cross-magnetic-field steps which occur as a result of positron-electron collisions. Within a constant magnetic field (e.g., 1 T), a collision between a positron and an electron can result in a correlated drift across the magnetic field for a continuous range of impact parameters. Within this range, drift distances orders of magnitude larger than that associated with like-charge collisions were observed by computer simulation.
Date: March 5, 2015
Creator: Aguirre, F. F. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Accelerator-based fusion with a low temperature target

Description: This article reports a study of a cold target with a high Fermi energy in light of recent research that points to a new phase of hydrogen, which is hypothesized to be related to metallic hydrogen. It has been shown that if the energy transfer between injected ions and target electrons is sufficiently small, net energy gain can be achieved. As such, the target is considered to be composed of nuclei and delocalized electrons.
Date: April 19, 2013
Creator: Phillips, R. E. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Dual levitated coils for antihydrogen production

Description: Article on theoretical and experimental efforts to use dual levitated coils to confine relatively large, cold, dense non-drifting recombining antihydrogen plasmas. The theoretical effort includes the development of a classical trajectory Monte Carlo simulation of confinement. The experimental effort includes levitation of a NdFeB permanent ring magnet, which produces a magnetic field that is qualitatively similar to the field that would be produced by the two coaxial superconducting magnetic coils.
Date: April 19, 2013
Creator: Wofford, Joshua D. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Effect of a finite antiproton mass on antihydrogen synthesis via magnetobound positronium within electron-positron-antiproton plasmas

Description: This article describes a study that was conducted to determine what would happen if a magnetobound positronium system encountered a finite-mass antiproton. The simulation incorporates a strong magnetic field (1 T) similar to that found within Penning traps. The simulation shows that with a finite-mass antiproton, the electron will be ejected from the system, and the positron is captured into a bound state with an antiproton thereby synthesizing antihydrogen.
Date: July 2016
Creator: Thornton, E. A. & Ordonez, Carlos A.
Partner: UNT College of Arts and Sciences
open access

Space-charge-based electrostatic plasma confinement involving relaxed plasma species

Description: In this article, a numerical study is reported on the equilibrium properties of a surface-emitted or edge-confined non-drifting plasma. A self-consistent finite-differences evaluation of the electrostatic potential is carried out for a non-neutral plasma that follows a Boltzmann density distribution.
Date: October 23, 2012
Creator: Pacheco, J. L.; Ordonez, Carlos A. & Weathers, Duncan L.
Partner: UNT College of Arts and Sciences
open access

Biochemical and molecular-genetic characterization of SFD1’s involvement in lipid metabolism and defense signaling

Description: Article describes study which sought to to determine if the dihydroxyacetone phosphate (DHAP) reductase activity and chloroplast localization are required for the Arabidopsis thaliana SFD1 (suppressor of fatty acid desaturase deficiency1) gene’s involvement in galactolipid metabolism and systemic acquired resistance (SAR) signaling.
Date: February 7, 2012
Creator: Lorenc-Kukula, Katarzyna; Chaturvedi, Ratnesh; Roth, Mary; Welti, Ruth & Shah, Jyoti
Partner: UNT College of Arts and Sciences
open access

Evidence for the Involvement of Electrical, Calcium and ROS Signaling in the Systemic Regulation of Non-Photochemical Quenching and Photosynthesis

Description: Article presents study in which pulse amplitude-modulated Chl fluorescence imaging and surface electrical potential measurements accompanied by pharmacological treatments were employed to study stimuli-induced electrical signals in leaves from a broad range of plant species and in Arabidopsis thaliana mutants.
Date: February 10, 2017
Creator: Białasek, Maciej; Górecka, Magdalena; Mittler, Ron & Karpiński, Stanisław
Partner: UNT College of Arts and Sciences
open access

The Differences between NAD-dependent malic enzyme and NADP-dependent malic enzyme Subtypes of C4 Photosynthesis: More than Decarboxylating Enzymes

Description: Article addresses the differences in evolutionary scenario, leaf anatomy, and especially C4 metabolic flow, C4 transporters, and cell-specific function deduced from recently reported cell-specific transcriptomic, proteomic, and metabolic analyses of NAD-dependent malic enzyme (NAD-ME) and NADP-dependent malic enzyme (NADP-ME) subtypes.
Date: October 13, 2016
Creator: Rao, Xiaolan & Dixon, Richard A.
Partner: UNT College of Arts and Sciences
open access

SPHK1 regulates proliferation and survival responses in triple-negative breast cancer

Description: Article describes study suggesting that the inhibation of sphingosine kinase 1 (SPHK1) can attenuate ERK1/2 and AKT signaling and reduce growth of triple-negative breast cancer (TNBC) cells in vitro and in a xenograft SCID mouse model.
Date: March 27, 2014
Creator: Datta, Arpita; Loo, Ser Yue; Huang, Baohua; Wong, Lingkai; Tan, Sheryl S.L.; Tan, Tuan Zea et al.
Partner: UNT College of Arts and Sciences
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