Browsing College of Sciences and Mathematics by Issue Date
Now showing items 201-220 of 389
With Big Data Comes Big Responsibilities for Science Equity Research
(2020-05-26)
Our ability to collect and access large quantities of data over the last decade has been revolutionary for many social sciences. Suddenly, it is possible to measure human behavior, performance, and activity on an unprecedented ...
Proton velocity ring-driven instabilities in the inner magnetosphere: Linear theory and particle-in-cell simulations
(2020-06-03)
Linear dispersion theory and electromagnetic particle-in-cell (PIC) simulations are used to investigate linear growth and nonlinear saturation of the proton velocity ring-driven instabilities, namely, ion Bernstein instability ...
Contrasting evolution of virulence and replication rate in an emerging bacterial pathogen
(2020-05-26)
Host resistance through immune clearance is predicted to favor pathogens that are able to transmit faster and are hence more virulent. Increasing pathogen virulence is, in turn, typically assumed to be mediated by increasing ...
Ion Bernstein instability dependence on the proton-to-electron mass ratio: Linear dispersion theory
(2020-06-03)
Fast magnetosonic waves, which have as their source ion Bernstein instabilities driven by tenuous ring-like proton velocity distributions, are frequently observed in the inner magnetosphere. One major difficulty in the ...
Spectral properties and associated plasma energization by magnetosonic waves in the Earth's magnetosphere: Particle-in-cell simulations
(2020-06-01)
In this paper, we perform a 1-D particle-in-cell (PIC) simulation model consisting of three species, cold electrons, cold ions, and energetic ion ring, to investigate spectral structures of magnetosonic waves excited by ...
Hall effect control of magnetotail dawn-dusk asymmetry: A three-dimensional global hybrid simulation
(2020-06-03)
Magnetotail reconnection and related phenomena (e.g., flux ropes, dipolarizing flux bundles, flow bursts, and particle injections) occur more frequently on the duskside than on the dawnside. Because this asymmetry can ...
Fast Magnetosonic Waves Observed by Van Allen Probes: Testing Local Wave Excitation Mechanism
(2020-05-28)
Linear Vlasov theory and particle-in-cell (PIC) simulations for electromagnetic fluctuations in a homogeneous, magnetized, and collisionless plasma are used to investigate a fast magnetosonic wave event observed by the Van ...
Generation of rising-tone chorus in a two-dimensional mirror field by using the general curvilinear PIC code
(2020-05-29)
Recently, the generation of rising-tone chorus has been implemented with one-dimensional (1-D) particle-in-cell (PIC) simulations in an inhomogeneous background magnetic field, where both the propagation of waves and motion ...
EUV emissions from solar wind charge exchange in the Earth's magnetosheath: Three-dimensional global hybrid simulation
(2020-06-05)
In this paper, a three-dimensional (3-D) global hybrid simulation code and a 3-D geocoronal hydrogen model are used to systematically study the extreme ultraviolet (EUV) emissions at 30.4nm produced by solar wind charge ...
Maskelynite formation via solid-state transformation: Evidence of infrared and X-ray anisotropy
(2020-06-05)
We present the results of a combined study of shocked labradorite from the Lonar crater, India, using optical microscopy, micro-Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high-energy X-ray total ...
Reactive transport of trace elements and isotopes in the Eutaw coastal plain aquifer, Alabama
(2020-06-18)
[1] We integrate groundwater geochemistry, mineralogy, and numerical modeling techniques to study the reactive transport of heavy metals and isotopes in the Eutaw coastal plain aquifer, Alabama. Geochemical data show that ...
Global patterns of Joule heating in the high-latitude ionosphere
(2020-06-18)
[1] A compiled empirical global Joule heating (CEJH) model is described in this study. This model can be used to study Joule heating patterns, Joule heating power, potential drop, and polar potential size in the high-latitude ...
Global-scale hybrid simulation of dayside magnetic reconnection under southward IMF: Structure and evolution of reconnection
(2020-06-12)
Magnetopause reconnection is investigated with our 3-D self-consistent global hybrid simulation model. The magnetic configuration and evolution of Flux Transfer Events (FTEs) and the associated ion density and ion velocity ...
Three-dimensional hybrid simulation of magnetosheath reconnection under northward and southward interplanetary magnetic field
(2020-06-16)
A three-dimensional (3-D) global hybrid simulation is carried out for the generation and structure of magnetic reconnection in the magnetosheath because of the interaction of an interplanetary tangential discontinuity (TD) ...
Evolution of low-altitude and ring current ENA emissions from a moderate magnetospheric storm: Continuous and simultaneous TWINS observations
(2020-06-12)
The moderate storm of 22 July 2009 is the largest measured during the extended solar minimum between December 2006 and March 2010. We present observations of this storm made by the two wide-angle imaging neutral-atom ...
DAVIS: A direct algorithm for velocity-map imaging system
(2020-06-25)
In this work, we report a direct (non-iterative) algorithm to reconstruct the three-dimensional (3D) momentum-space picture of any charged particles collected with a velocity-map imaging system from the two-dimensional ...
An Overlooked Hotspot? Rapid Biodiversity Assessment Reveals a Region of Exceptional Herpetofaunal Richness in the Southeastern United States
(2022-07-29)
We conducted a competitive bioblitz survey in four Georgia counties to raise awareness of a unique and species rich herpetofauna in the Pine Mountain/ Fall Line Sandhills Region of Georgia, and compared documented species ...
Global observations of ring current dynamics during corotating interaction region-driven geomagnetic storms in 2008
(2020-06-12)
We examine the evolution of the ring current during the main and early recovery phases of three geomagnetic storms driven by corotating interaction regions. The equatorial energy density profiles of 5-30 keV ions are ...
Visitors to Southeastern Hawkmoth Flowers
(2022-07-29)
- Despite global concern for the status of animal pollinators, studies on
pollination systems in the southeastern United States are disproportionately low
compared to the diversity of this region. For example, sphingophilous, ...
Seasonal Shifts in Reproduction Depend on Prey Availability for an Income Breeder
(2022-03-04)
The evolution of reproductive strategies depends on local environmental conditions. When environments are seasonal, selection favors individuals that align changes in key reproductive traits with seasonal shifts in habitat ...