Physical Sciences and Mathematics Commons^™

Characterization Of Electron Yield Suppression With Carbon Nanotube Forest Grown On Silicon Substrates, Brian Wood, Jordan Lee, Justin Christensen, Gregory Wilson, Jr Dennison, T. -C. Shen

Presentations

No abstract provided.

Characterization Of Electron Yield Suppression With Carbon Nanotube Forest Grown On Silicon Substrates, Brian Wood, Jordan Lee, Gregory Wilson, Jr Dennison, T. -C. Shen

Presentations

No abstract provided.

Optical Transmission Of Irradiated Optical Filters, Ashlan Keeler, Jr Dennison, Brian Wood, Jonh Mojica Decena

Presentations

No abstract provided.

Characterizing Vibrationally Induced Damage Of Carbon Nanotube Forests, Jordan Lee, Brian Wood, Ashlan Keeler, Jr Dennison, T. -C. Shen

Presentations

No abstract provided.

Real-Time Video Processing Of Arcing Events To Determine Coincidence, Jr Dennison, Gregory Wilson, Jonh Mojica Decena, Brian Wood

Presentations

No abstract provided.

Optical Transmission Of Irradiated Optical Filters, Jr Dennison, Ashlan Keeler, Brian Wood, Jonh Mojica Decena

Presentations

No abstract provided.

Electron Yield Measurements Of Multilayer Conductive Materials, Gregory Wilson, Matthew Robertson, Jordan Lee, Jr Dennison

Presentations

No abstract provided.

Validation Of Ionospheric Specifications During Geomagnetic Storms: Tec And Fof2 During The 2013 March Storm Event, Jasoon S. Shim, Ioanna Tsagouri, Larisa Goncharenko, Lutz Rastaetter, Maria Kuznetsova, Dieter Bilitza, M. Codrescu, A. J. Coster, Stanley C. Solomon, M. Fedrizzi, Matthias Förster, Timothy J. Fuller-Rowell, Larry Gardner, Joseph Huba, A. A. Namgaladze, Boris E. Prokhorov, Aaron J. Ridley, Ludger Scherliess, Robert W. Schunk, Jan Josef Sojka, Lie Zhu

All Physics Faculty Publications

To address challenges of assessing space weather modeling capabilities, the CommunityCoordinated Modeling Center is leading a newly establishedInternational Forum for Space WeatherModeling Capabilities Assessment. This paper presents preliminary results of validation of modeled foF2 (F₂ layer critical frequency) and TEC (total electron content) during the first selected 2013 March storm event (17 March 2013). In this study, we used eight ionospheric models ranging from empirical to physics-based, coupled ionosphere-thermosphere and data assimilation models. The quantities we considered are TEC and foF2 changes and percentage changes compared to quiet time background, and the maximum and minimum percentage changes. In addition, …

Sustaining Wetlands To Mitigate Disasters And Protect People, Joanna Endter-Wada, Karin M. Kettenring, Ariana E. Sutton-Grier

Watershed Sciences Faculty Publications

Hurricanes, flooding, droughts. Weather‐related disasters are dominating news cycles and causing widespread destruction, most recently with Typhoon Mangkhut and Hurricane Florence. The US had the most catastrophic hurricane season on record in 2017, with hundreds of billions of dollars in estimated damages. California is experiencing unprecedented tragedies from widespread wildfires and increased vulnerability to storms. Disasters that were once uncommon appear to be the new norm globally, and evidence suggests the frequency and impacts of extreme events will increase further with climate change.

Modeling The Midlatitude Ionosphere Storm-Enhanced Density Distribution With A Data Assimilation Model, Larry Gardner, Robert W. Schunk, Ludger Scherliess, Vincent Eccles, Susanto Basu, Cesar E. Valladares

All Physics Faculty Publications

The Utah State University Global Assimilation of Ionospheric Measurements‐Gauss Markov model has been used to investigate the distribution of ionospheric plasma during storm times over the continental United States. Storm periods dramatically increase the effects of space weather on the ionosphere and upper atmosphere, leading to impacts on over‐the‐horizon radars, Global Positioning System location determination, spacecraft charging, power grid overloads, and disruption of the Federal Aviation Administration Wide Area Augmentation System to name a few. Four storm periods were investigated where strong storm‐enhanced densities (SEDs) were present: two strong, October 2003 and November 2003, and two moderate, August 2010 and …

Characterization Of The Effects Of Radiation On Skeletal And Smooth Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis

Posters

Muscular atrophy is a serious issue for extended spaceflight. Understanding and preventing the role of ionizing radiation in skeletal muscle loss would preserve the strength and endurance of astronauts and enable longer duration space travel and exploration. Irradiation was performed in the USU material physics group's Space Suvivability Test Chamber. C2C12 and CRL-1999 cells were exposed to dosages ranging from 0.5 - 36.8 Gy. Cell viability and growth rate were measured immediately following irradiation.

Long-Term Stability Of Ion-Beam Treated Space Polymers In Geo-Simulated Environment, J Kleiman, Z Iskanderova, L Krishtein, Jr Dennison, Brian Wood, C Best

Presentations

No abstract provided.

Long-Term Stability Of Ion-Beam Treated Space Polymers In Geo-Simulated Environment, J Kleiman, Z Iskanderova, C Best, Jr Dennison, Brian Wood

Presentations

It is a real challenge to reproduce various space environment conditions in ground-based facilities for testing of external space system materials and elements. This is due to the variety and complexity of the space environment conditions and their effects on materials and structures. The reliability of test results depends on accurate simulation of the critical factors and effects of the space environment for a particular mission. The main objectives of the simulation testing are to get the test results that are adequate to the material durability and functional behavior in a space environment.

As part of a large, multi-year program, …

How Design Features In Digital Math Games Support Learning And Mathematics Connections, Patricia S. Moyer-Packenham, Christina W. Lommatsch, Kristy Litster, Jill Ashby, Emma P. Bullock, Allison L. Roxburgh, Jessica F. Shumway, Emily Speed, Benjamin Covington, Christine Hartmann, Jody Clarke-Midura, Joel Skaria, Arla Westenskow, Beth L. Macdonald, Jurgen Symanzik, Kerry Jordan

Teacher Education and Leadership Faculty Publications

Current research shows that digital games can significantly enhance children’s learning. The purpose of this study was to examine how design features in 12 digital math games influenced children’s learning. The participants in this study were 193 children in Grades 2 through 6 (ages 8-12). During clinical interviews, children in the study completed pre-tests, interacted with digital math games, responded to questions about the digital math games, and completed post-tests. We recorded the interactions using two video perspectives that recorded children’s gameplay and responses to interviewers. We employed mixed methods to analyze the data and identify salient patterns in children’s …

An Updated Description Of The Hydrogen Bond And Related Noncovalent Bonds, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The hydrogen bond is typically introduced briefly in General Chemistry as a simple electrostatic phenomenon involving a small and select group of atoms, a definition which is typically unchanged through higher levels in the curriculum. But this definition has undergone dramatic modernization of which students should be made aware. The original formulation in terms of only F, O, and N atoms has broadened very considerably, encompassing C as well as atoms from lower rows in the periodic table. The influence of hybridization, substituents, and overall charge cannot be overlooked. In addition to the Coulombic attraction, there are other “covalent” contributors …

Triel-Bonded Complexes Between Trr3 (Tr = B, Al, Ga; R = H, F, Cl, Br, Ch3) And Pyrazine, Mariusz Michalczyk, Wiktor Zierkiewicz, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Complexes between TrR3 (Tr = B, Al, Ga; R= H, F, Cl, Br, CH3)molecules and pyrazine have been characterized at the MP2 and CCSD(T) levels of theory. The adducts can be grouped according to the type of molecular arrangement. The first situation places the Tr atom in the plane of the pyrazine ring and contains a triel bond to the N lone pair. For the boron complexes the orbital interaction energy is almost equal to the electrostatic component, while the former is only half the latter for Tr= Al and Ga. The two monomers are stacked above one another in …

Analytical Representations For Characterizing The Global Aviation Radiation Environment Based On Model And Measurement Databases, W. Kent Tobiska, Leonid Didkovsky, Kevin Judge, Seth Weiman, Dave Bouwer, Justin Bailey, Bill Atwell, Molly Maskrey, Chris Mertens, Yihua Zheng, Margaret Shea, Don Smart, Brad Gersey, Richard Wilkins, Duane Bell, Larry Gardner, Robert Fuschino

All Physics Faculty Publications

The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety climatological model and the Automated Radiation Measurements for Aerospace Safety (ARMAS) statistical database are presented as polynomial fit equations. Using equations based on altitude, L shell, and geomagnetic conditions an effective dose rate for any location from a galactic cosmic ray (GCR) environment can be calculated. A subset of the ARMAS database is represented by a second polynomial fit equation for the GCR plus probable relativistic energetic particle (REP; Van Allen belt REP) effective dose rates within a narrow band of L shells with altitudinal and geomagnetic dependency. Solar energetic particle …

Ability Of Ir And Nmr Spectral Data To Distinguish Between A Tetrel Bond And A Hydrogen Bond, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The placement of a nucleophile X along the R-CH3 axis of a methyl group can be described as either a trifurcated H-bond or as a tetrel bond between C and X. Quantum calculation of the vibrational and NMR spectral features of a number of systems are used to provide a framework by which to distinguish between the presence of a tetrel or H-bond. Both cationic and neutral methyl-containing Lewis acids (SMe3+, NMe4+, SMe2) are paired with both neutral and anionic Lewis bases (NH3, OH2, OCHNH2, OCH3-, OH-, HCOO-). As the base is moved away from the R-CH3 axis of the …

Waterfall Formation At A Desert River-Reservoir Delta Isolates Endangered Fishes, Charles N. Cathcart, Casey A. Pennock, Christopher A. Cheek, Mark C. Mckinstry, Peter D. Mackinnon, Mary M. Conner, Keith B. Gido

Wildland Resources Faculty Publications

Unforeseen interactions of dams and declining water availability have formed new obstacles to recovering endemic and endangered big-river fishes. During a recent trend of drying climate and declining reservoir water levels in the southwestern United States, a large waterfall has formed on two separate occasions (1989-1995 & 2001-present) in the transition zone between the San Juan River and Lake Powell reservoir because of deposited sediments. Because recovery plans for two large-bodied endangered fish species, razorback sucker (Xyrauchen texanus) and Colorado pikeminnow (Ptychocheilus lucius), include annual stockings in the San Juan River, this waterfall potentially blocks upstream …

Toward Audio Beehive Monitoring: Deep Learning Vs. Standard Machine Learning In Classifying Beehive Audio Samples, Vladmir Kulyukin, Sarbajit Mukherjee, Prakhar Amlathe

Computer Science Faculty and Staff Publications

Electronic beehive monitoring extracts critical information on colony behavior and phenology without invasive beehive inspections and transportation costs. As an integral component of electronic beehive monitoring, audio beehive monitoring has the potential to automate the identification of various stressors for honeybee colonies from beehive audio samples. In this investigation, we designed several convolutional neural networks and compared their performance with four standard machine learning methods (logistic regression, k-nearest neighbors, support vector machines, and random forests) in classifying audio samples from microphones deployed above landing pads of Langstroth beehives. On a dataset of 10,260 audio samples where the training and testing …

Efficiency Enhancement Of Perovskite Solar Cells With Plasmonic Nanoparticles: A Simulation Study, Ali Hajjiah, Ishac Kandas, Nader Shehata

Biology Faculty Publications

Recently, hybrid organic-inorganic perovskites have been extensively studied due to their promising optical properties with relatively low-cost and simple processing. However, the perovskite solar cells have some low optical absorption in the visible spectrum, especially around the red region. In this paper, an improvement of perovskite solar cell efficiency is studied via simulations through adding plasmonic nanoparticles (NPs) at the rear side of the solar cell. The plasmonic resonance wavelength is selected to be very close to the spectrum range of lower absorption of the perovskite: around 600 nm. Both gold and silver nanoparticles (Au and Ag NPs) are selected …

Simultaneous Rayleigh-Scatter And Sodium Resonance Lidar Temperature Comparisons In The Mesosphere-Lower Thermosphere, Leda Sox, Vincent B. Wickwar, Tao Yuan, Neal R. Criddle

All Physics Faculty Publications

The Utah State University (USU) campus (41.7°N, 111.8°W) hosts a unique upper atmospheric observatory that houses both a high-power, large-aperture Rayleigh lidar and a Na lidar. For the first time, we will present 19 nights of coordinated temperature measurements from the two lidars, overlapping in the 80–110 km observational range, over one annual cycle (summer 2014 to summer 2015). This overlap has been achieved through upgrades to the existing USU Rayleigh lidar that increased its observational altitude from 45–95 to 70–115 km and by relocating the Colorado State Na lidar to the USU campus. Previous climatological comparisons between Rayleigh and …

First Observed Temporal Development Of A Noctilucent Cloud Ice Void, Linda Megner, Jacek Stegman, Pierre-Dominique Pautet, Michael J. Taylor

All Physics Faculty Publications

Noctilucent clouds are ice clouds that appear high in the atmosphere, about 80 km above the summer pole. By observing them we have learned a lot about the remote and inaccessible region where they form. Recently, a satellite borne instrument discovered nearly circular ice-free regions within the clouds, denoted as “ice voids.” The origin of these voids is a mystery—we do not know what causes the clouds to disappear in large circular areas. So far these voids have only been observed from satellites, which only can take pictures of the clouds when they pass above once every 1.5 hr—longer than …

Genome-Wide Association Study For Variants That Modulate Relationships Between Cerebrospinal Fluid Amyloid-Beta 42, Tau, And P-Tau Levels, Taylor J. Maxwell, Chris Corcoran, Jorge L. Del-Aguila, John P. Budde, Yuetiva Deming, Carlos Cruchaga, Alison M. Goate, John S. K. Kauwe, Alzheimer's Disease Neuroimaging Initiative

Mathematics and Statistics Faculty Publications

Background: A relationship quantitative trait locus exists when the correlation between multiple traits varies by genotype for that locus. Relationship quantitative trait loci (rQTL) are often involved in gene-by-gene (G×G) interactions or gene-by-environmental interactions, making them a powerful tool for detecting G×G.

Methods: We performed genome-wide association studies to identify rQTL between tau and Aβ42 and ptau and Aβ42 with over 3000 individuals using age, gender, series, APOE ε2, APOE ε4, and two principal components for population structure as covariates. Each significant rQTL was separately screened for interactions with other loci for each trait in the rQTL model. Parametric bootstrapping …

The Geometry Of N=3 Ads4 In Massive Iia, G. Bruno De Luca, Gabriele Lo Monaco, Niall T, Macpherson, Alessandro Tomasiello, Oscar J. Varela

All Physics Faculty Publications

The geometry of the N=3" role="presentation">N=3, SO(4)-invariant, AdS₄ solution of massive type IIA supergravity that uplifts from the N=3" role="presentation">N=3 vacuum of D = 4 N=8" role="presentation">N=8 dyonic ISO(7) supergravity is investigated. Firstly, a D = 4, SO(4)-invariant restricted duality hierarchy is constructed and used to uplift the entire, dynamical SO(4)-invariant sector to massive type IIA. The resulting consistent uplift formulae are used to obtain a new local expression for the N=3" role="presentation">N=3 AdS₄ solution in massive IIA and analyse its geometry. Locally, the internal S⁶ geometry corresponds to a warped fibration of …

Long-Term Evolution Of Sand Transport Through A River Network: Relative Influences Of A Dam Versus Natural Changes In Grain Size From Sand Waves, David J. Topping, Erich R. Mueller, John C. Schmidt, Ronald E. Griffiths, David J. Dean, Paul E. Grams

Watershed Sciences Faculty Publications

Temporal and spatial nonuniformity in supplies of water and sand in a river network leads to sand transport that is in local disequilibrium with the upstream sand supply. In such river networks, sand is transported downstream as elongating waves in which coupled changes in grain size and transport occur. Depending on the magnitude of each sand-supplying event and the interval between such events, changes in bed-sand grain size associated with sand-wave passage may more strongly regulate sand transport than do changes in water discharge. When sand transport is controlled more by episodic resupply of sand than by discharge, upstream dam …

On The Responses Of Mesosphere And Lower Thermosphere Temperatures To Geomagnetic Storms At Low And Middle Latitudes, Jingyuan Li, Wenbin Wang, Jianyong Lu, Tao Yuan, Jia Yue, Xiao Liu, Kedeng Zhang, Alan G. Burns, Yongliang Zhang, Zheng Li

All Physics Faculty Publications

Observations from lidars and satellites have shown that large neutral temperature increases and decreases occur in the middle and low latitudes of the mesosphere and lower thermosphere region during geomagnetic storms. Here we undertake first-principles simulations of mesosphere and lower thermosphere temperature responses to storms using the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model to elucidate the nature and causes of these changes. Temperature variations were not uniform; instead, nighttime temperatures changed earlier than daytime temperatures, and temperatures changed earlier at high latitudes than at low ones. Furthermore, temperatures increased in some places/times and decreased in others. As the simulation …

The Influence Of Arctic Amplification On Mid-Latitude Summer Circulation, Dim Coumou, Giorgia Di Capua, Steve Vavrus, Lei Wang, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

Accelerated warming in the Arctic, as compared to the rest of the globe, might have profound impacts on mid-latitude weather. Most studies analyzing Arctic links to mid-latitude weather focused on winter, yet recent summers have seen strong reductions in sea-ice extent and snow cover, a weakened equator-to-pole thermal gradient and associated weakening of the mid-latitude circulation. We review the scientific evidence behind three leading hypotheses on the influence of Arctic changes on mid-latitude summer weather: Weakened storm tracks, shifted jet streams, and amplified quasi-stationary waves. We show that interactions between Arctic teleconnections and other remote and regional feedback processes could …

Remarks On Legendrian Self-Linking, Chris Beasley, Brendan Mclellan, Ruoran Zhang

Mathematics and Statistics Faculty Publications

The Thurston-Bennequin invariant provides one notion of self-linking for any homologically-trivial Legendrian curve in a contact three-manifold. Here we discuss related analytic notions of self-linking for Legendrian knots in R³. Our definition is based upon reformulation of the elementary Gauss linking integral and is motivated by ideas from supersymmetric gauge theory. We recover the Thurston-Bennequin invariant as a special case.

Regium Bonds Between Mn Clusters (M=Cu,Ag,Au And N=2-6) And Nucleophiles Nh3 And Hcn, Wiktor Zierkiewicz, Mariusz Michalczyk, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The most stable geometries of the coinagemetal (or regium) atom (Cu, Ag, Au) clusters Mn for n up to 6 are all planar, and adopt the lowest possible spin multiplicity. Clusters with even numbers of M atoms are thus singlets, while those with odd n are open-shell doublets. Examination of the molecular electrostatic potential (MEP) of each cluster provides strong indications of the most likely site of attack by an approaching nucleophile, generally one of two positions. A nucleophile (NH3 or HCN) most favorably approaches one particular M atom of each cluster, rather than a bond midpoint or face. In …