Physical Sciences and Mathematics Commons^™

Predictive Formula For Electron Penetration Depth Of Diverse Materials Over Large Energy Ranges, Anne C. Starley, Gregory Wilson, Lisa D. Montierth, Jr Dennison

Conference Proceedings

An empirical model that predicts the approximate electron penetration depth—or range—of some common materials has been extended to predict the range for a broad assortment of other materials. The electron range of a material is the maximum distance electrons can travel through a material, before losing all of their incident kinetic energy. The original model used the Continuous Slow Down Approximation (CSDA) for energy deposition in a material to develop a composite analytical formula which estimated the range from10 MeV with an uncertainty of200 materials which have tabulated range and inelastic mean free path data in the NIST ESTAR and …

Voltage Ramp-Rate Dependence Of Dc Breakdown In Polymeric Insulators: Physical Models Versus Data, Allen Andersen, Krysta Moser, Jr Dennison

Conference Proceedings

The standard handbook values for dielectric breakdown strength of necessity come from accelerated test methods. In some cases, the breakdown voltage may vary significantly with voltage ramp rates; therefore, a theoretical model for the ramp-rate dependence of breakdown is needed to extrapolate from realistic tests to long-duration material service lifetimes. Series of step-up to breakdown tests were performed for ramp rates from 0.5 to 500 V/s for biaxially-oriented polypropylene (BOPP), low density polyethylene (LDPE), and polyimide (PI) films. The data were fit with standard empirical methods, as well as two physics-based defect-driven models. Empirical models can be fit to a …

The Space Survivability Test Chamber, Alex Souvall, Benjamin Russon, Brian Wood, Gregory Wilson, Jr Dennison

Posters

No abstract provided.

Voltage Ramp-Rate Dependence Of Dc Breakdown In Polymeric Insulators: Physical Models Versus Data, Allen Andersen, Krysta Moser, Jr Dennison

Posters

Purpose/Aim

The standard handbook values for dielectric breakdown strength of necessity come from accelerated test methods. In some applications the breakdown voltage may vary significantly with voltage ramp rates; therefore, a theoretical model for the ramp-rate dependence of breakdown is needed to extrapolate from realistic tests to long-duration material service lifetimes.

Experimental/Modeling methods

Series of step-up to breakdown tests were performed for ramp rates from 0.5 to 500 V/s for biaxially-oriented polypropylene (BOPP), low density polyethylene (LDPE), and polyimide (PI) films. The data were fit with standard empirical methods, as well as two physics-based defect-driven models.

Results/discussion

Table 1 in …

The First Calibration Of Sbf Using Multi-Conjugate Adaptive Optics, Zachary Gibson, Joseph B. Jenson, John P. Blakeslee, Mischa Schirmer

Presentations

We measured Surface Brightness FluctuaIons (SBF) in three galaxies, ESO137-G006, NGC 3309, and NGC 5128, using the GeMS MulI-Conjugate AdapIve OpIcs (MCAO) system on the Gemini South telescope. ESO137-G006 is located in the Norma Cluster, NGC 3309 is located in the Hydra Cluster, while NGC 5128, also known as Centaurus A, is a nearby galaxy with numerous other distance measurements, including Cepheids. These galaxies were observed as a path finder to establish the SBF technique using the MCAO system. The J and Ks-band images taken with MCAO were astrometrically corrected and combined using the THELI so_ware.1 This method allowed us …

Space Environment Effects Of Ionizing Radiation On Seed Germination And Growth, Alexander Souvall, Jr Dennison, Takayuki Sakai, Yuta Takahashi, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Toshihiro Kameda, Shaunda Wenger

Presentations

No abstract provided.

The Kretschmann Scalar, Charles G. Torre

How to... in 10 minutes or less

On a pseudo-Riemannian manifold with metric g, the "Kretschmann scalar" is a quadratic scalar invariant of the Riemann R tensor of g, defined by contracting all indices with g. In this worksheet we show how to calculate the Kretschmann scalar from a metric.

Electrochemical Oxidation To Construct A Nickel Sulfide/Oxide Heterostructure With Improvement Of Capacitance, Xuan Liu, Bo You, Xin-Yao Yu, Jeffrey Chipman, Yujie Sun

Chemistry and Biochemistry Faculty Publications

Supercapacitors have been widely recognized as a promising device for the storage of renewable energy. Herein, a facile electrochemical oxidation strategy is described to construct a nickel sulfide/oxide heterostructure which enhances the specific areal capacitance of Ni₃S₂ electrode (2035 mF cm^-2 vs. 31 mF cm^-2 at a current density of 8 mA cm^-2), while still maintaining great stability, showing no performance degradation after 5000 charge-discharge cycles. Its exceptional capacitance, advanced rate capability, and superior cycling stability are attributed to the transformed composition and unique nanostructure achieved during electrochemical oxidation, which can provide a …

Comparison Of Π-Hole Tetrel Bonding With Σ-Hole Halogen Bonds In Complexes Of Xcn (X = F, Cl, Br, I) And Nh3, Steve Scheiner, Vincent De Paul Nziko

Chemistry and Biochemistry Faculty Publications

In addition to the standard halogen bond formed when NH₃ approaches XCN (X=F,Cl,Br,I) along its molecular axis, a perpendicular approach is also possible, toward a π-hole that is present above the X-C bond. MP2/aug-cc-pVDZ calculations indicate the latter geometry is favored for X=F, and the σ-hole structure is preferred for the heavier halogens. The π-hole structure is stabilized by charge transfer from the NH₃ lone pair into the π*(CN) antibonding orbital, and is characterized by a bond path from the N of NH₃ to the C atom of XCN, a form of tetrel bond. The most stable …

Cofibrations In The Category Of Noncommutative Cw Complexes, Vida Milani, Ali Asghar Rezaei, Seyed M.H. Mansourbeigi

Computer Science Student Research

Cofibration in the category of noncommutative CW complexes is defined. The C*-algebraic counterparts of topological mapping Cylinder and mapping cone are presented as examples of noncommutative CW complex cofibres. As a generalization, the concepts of noncommutative mapping cylindrical and conical telescope are introduced to provide more examples of NCCW complex cofibres. Their properties and K-theoretic behavior are also studied in detail. We will see that they carry the properties similar to the topological properties of their CW complex counterparts.

Data From: How Uncertainty In The Neutral Wind Limits The Accuracy Of Ionospheric Modeling And Forecasting, Michael David, Jan Sojka, Robert W. Schunk

Browse all Datasets

Output files from runs of the TDIM ionospheric model used for the figures and calculations in the article in JGR Space Physics.

Long-Term Landscape Changes In A Subalpine Spruce-Fir Forest In Central Utah, Usa, Jesse L. Morris, R. Justin Derose, Andrea R. Brunelle

Wildland Resources Faculty Publications

Background: In Western North America, increasing wildfire and outbreaks of native bark beetles have been mediated by warming climate conditions. Bioclimatic models forecast the loss of key high elevation species throughout the region. This study uses retrospective vegetation and fire history data to reconstruct the drivers of past disturbance and environmental change. Understanding the relationship among climate, antecedent disturbances, and the legacy effects of settlement-era logging can help identify the patterns and processes that create landscapes susceptible to bark beetle epidemics. Methods: Our analysis uses data from lake sediment cores, stand inventories, and historical records. Sediment cores were dated with …

Selection For Forage And Avoidance Of Risk By Woodland Caribou (Rangifer Tarandus Caribou) At Coarse Andlocal Scales, Madeleine T. Mcgreer, Erin E. Mallon, Lucas M. Vander Vennen, Philip A. Wiebe, James A. Baker, Glen S. Brown, Tal Avgar, Jevon Hagens, Andrew M. Kittle, Anna Mosser, Garrett M. Street, Doug E. B. Reid, Arthur R. Rodgers, Jennifer Shuter, Ian D. Thompson, Et Al.

Wildland Resources Faculty Publications

The relationship between selection at coarse and fine spatiotemporal spatial scales is still poorly understood. Some authors claim that, to accommodate different needs at different scales, individuals should have contrasting selection patterns at different scales of selection, while others claim that coarse scale selection patterns should reflect fine scale selection decisions. Here we examine site selection by 110 woodland caribou equipped with GPS radio‐collars with respect to forage availability and predation risk across a broad gradient in availability of both variables in boreal forests of Northern Ontario. We tested whether caribou selection for forage and avoidance of risk was consistent …

Comparison Of Coincident Rayleigh-Scatter And Sodium Resonance Lidar Temperature Measurements From The Mesosphere-Lower-Thermosphere Region, Leda Sox, Vincent B. Wickwar, Neal R. Criddle, Tao Yuan

All Physics Faculty Presentations

There are relatively few instruments that have the capabilities to make near continuous measurements of the mesosphere-lower-thermosphere (MLT) region. Rayleigh scatter and resonance lidars, particularly sodium resonance lidar, have been the two dominant ground-based techniques for acquiring mesosphere and MLT vertical temperature profiles, respectively, for more than two decades. With these measurements, the dynamics (gravity waves, tides) and long-term temperature trends (upper atmosphere cooling) of the MLT region can be studied. The Utah State University (USU; 41.7º N, 111.8º W) campus hosts a unique upper atmospheric observatory which houses both a high-power, large-aperture Rayleigh lidar and a sodium resonance Doppler …

Comparison Of Coincident Rayleigh-Scatter And Sodium Resonance Lidar Temperature Measurements From The Mesosphere-Lower-Thermosphere Region, Leda Sox, Vincent B. Wickwar, Neal R. Criddle, Tao Yuan

All Physics Faculty Publications

There are relatively few instruments that have the capabilities to make near continuous measurements of the mesosphere-lower-thermosphere (MLT) region. Rayleigh scatter and resonance lidars, particularly sodium resonance lidar, have been the two dominant ground-based techniques for acquiring mesosphere and MLT vertical temperature profiles, respectively, for more than two decades. With these measurements, the dynamics (gravity waves, tides) and long-term temperature trends (upper atmosphere cooling) of the MLT region can be studied. The Utah State University (USU; 41.7º N, 111.8º W) campus hosts a unique upper atmospheric observatory which houses both a high-power, large-aperture Rayleigh lidar and a sodium resonance Doppler …

Microsolvation Of Anions By Molecules Forming Ch∙∙X- Hydrogen Bonds, Steve Scheiner, Binod Nepal

Chemistry and Biochemistry Faculty Publications

Various anions were surrounded by n molecules of CF₃H, which was used as a prototype CH donor solvent, and the structures and energies studied by M06-2X calculations with a 6-31+G∗∗ basis set. Anions considered included the halides F^-, Cl^-, Br^- and I^-, as well as those with multiple proton acceptor sites: CN^-, NO₃ ^-, HCOO^-, CH₃COO^-, HSO₄ ^-, H₂PO₄ ^-, and anions with higher charges SO₄ ^2-, HPO₄ ^2- and PO_{4 …}

Genetic Analysis Of The Henry Mountains Bison Herd, Dustin H. Ranglack, Lauren K. Dobson, Johan T. Du Toit, James Derr

Wildland Resources Faculty Publications

Wild American plains bison (Bison bison) populations virtually disappeared in the late 1800s, with some remnant animals retained in what would become Yellowstone National Park and on private ranches. Some of these private bison were intentionally crossbred with cattle for commercial purposes. This forced hybridization resulted in both mitochondrial and nuclear introgression of cattle genes into some of the extant bison genome. As the private populations grew, excess animals, along with their history of cattle genetics, provided founders for newly established public bison populations. Of the US public bison herds, only those in Yellowstone and Wind Cave National Parks (YNP …

Integrated Step Selection Analysis: Bridgingthe Gap Between Resource Selection And Animal Movement, Tal Avgar, Jonathan R. Potts, Mark A. Lewis, Mark S. Boyce

Wildland Resources Faculty Publications

A resource selection function is a model of the likelihood that an available spatial unit will be used by an animal, given its resource value. But how do we appropriately define availability? Step selection analysis deals with this problem at the scale of the observed positional data, by matching each ‘used step’ (connecting two consecutive observed positions of the animal) with a set of ‘available steps’ randomly sampled from a distribution of observed steps or their characteristics. Here we present a simple extension to this approach, termed integrated step selection analysis (iSSA), which relaxes the implicit assumption that observed movement …

On The Construction Of Simply Connected Solvable Lie Groups, Mark E. Fels

Research Vignettes

This worksheet contains the implementation of Theorems 4.2, 5.4 and 5.7 in the paper On the Construction of Solvable Lie Groups. All the examples in the paper are demonstrated here, along with one in Section 6 that was too long to include in the article.

Substituent Effects On The Binding Of Halides By Neutral And Dicationic Bis-Triazolium Receptors, Binod Nepal, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The effects of substituent and overall charge upon the binding of a halide anion by a bis-triazolium receptor are studied by M06-2X DFT calculations, with the aug-cc-pVDZ basis set. Comparison is also made between a receptor that engages in H-bonds, with a halogen-bonding species. Fluoride is clearly most strongly bound, followed by Cl-, Br-, and I- in that order. The dicationic receptor engages in stronger complexes, but not by a very wide margin compared to its neutral counterpart. The binding is enhanced as the substituent on the two triazolium rings becomes progressively more electron-withdrawing. Halogen-substituted receptors, whether neutral or cationic, …

The First Bromeligenous Species Of Dendropsophus (Anura: Hylidae) From Brazil's Atlantic Forest, Rodrigo Barbosa Ferreira, Julián Faivovich, Karen H. Beard, José P. Pombal Jr

Wildland Resources Faculty Publications

We describe a new treefrog species of Dendropsophus collected on rocky outcrops in the Brazilian Atlantic Forest. Ecologically, the new species can be distinguished from all known congeners by having a larval phase associated with rainwater accumulated in bromeliad phytotelms instead of temporary or lentic water bodies. Phylogenetic analysis based on molecular data confirms that the new species is a member of Dendropsophus; our analysis does not assign it to any recognized species group in the genus. Morphologically, based on comparison with the 96 known congeners, the new species is diagnosed by its small size, framed dorsal color pattern, and …

Mantle-Derived Helium In Hot Springs Of The Cordillera Blanca, Peru: Implications For Mantle-To-Crust Fluid Transfer In A Flat-Slab Subduction Setting, Dennis L. Newell, Micah J. Jessup, David R. Hilton, Colin Shaw, Cameron Hughes

Geosciences Faculty Publications

Fault-controlled hot springs in the Cordillera Blanca, Peru provide geochemical evidence of mantle-derived fluids in a modern flat-slab subduction setting. The Cordillera Blanca is an ~200km-long mountain range that contains the highest peaks in the Peruvian Andes, located in an amagmatic reach of the Andean arc. The Cordillera Blanca detachment defines the southwestern edge of the range and records a progression of top-down-to-the-west ductile shear to brittle normal faulting since ~5Ma. Hot springs, recording temperatures up to 78°C, issue along this fault zone and are CO₂-rich, near neutral, alkaline-chloride to alkaline-carbonate waters, with elevated trace metal contents including …

The Schwarzschild Solution And Timelike Geodesics, Matthew B. Ross

Physics Capstone Projects

General Relativity is a major area of study in physics. It allows us to calculate the motion and interaction of particles in a non-Euclidean space-time. This presentation will examine the process of finding the Schwarzschild metric tensor field by finding a solution of the Einstein Equation for a non-rotating spherical mass. A general form of the Schwarzschild metric tenor field will be used to calculate the Riemann curvature tensor and subsequently the Ricci tensor and Ricci scalar which will be used to find a vacuum solution to the Einstein Equation. Once the solutions of the Einstein Equation are found, they …

Spatiotemporal Patterns Of Ring-Width Variability In The Northern Interior West, R. Justin Derose, John D. Shaw, James N. Long

Wasatch Dendroclimatology Research

A fundamental goal of forest biogeography is to understand the factors that drive spatiotemporal variability in forest growth across large areas (e.g., states or regions). The ancillary collection of increment cores as part of the IW FIA Program represents an important non-traditional role for the development of unprecedented data sets. Individual-tree growth data from increment cores were paired with plot-level variables from the inventory to investigate the spatiotemporal growth patterns for Douglas-fir, ponderosa pine, common pinyon, and limber pine over the northern portion of the Interior West (Idaho, Montana, Wyoming, Utah, and Colorado). Based on dendrochronological theory proposed over 50 …

Estimation Of Cold Plasma Outflow During Geomagnetic Storms, S. Haaland, A. Eriksson, M. Andre, L. Maes, L. Baddeley, A. Barakat, R. Chappell, V. Eccles, C. Johnsen, B. Lybekk, K. Li, A. Pedersen, Robert W. Schunk, D. Welling

All Physics Faculty Publications

Low-energy ions of ionospheric origin constitute a significant contributor to the magnetospheric plasma population. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and typically in regions of space where spacecraft attain a positive charge due to solar illumination. Cold ions are therefore shielded from the satellite particle detectors. Furthermore, spacecraft can only cover key regions of ion outflow during segments of their orbit, so additional complications arise if continuous longtime observations, such as during a geomagnetic storm, are needed. In this paper we suggest a new approach, based on a combination of synoptic …

Predictive Formula For Electron Range Over A Large Span Of Energy, Anne C. Starley

Reports

A model developed by the Materials Research Group that calculates electron penetration range of some common materials, has been greatly expanded with the hope that such extensions will predict the range in other, perhaps, more interesting materials. Developments in this extended model aid in predicting the approximate penetration depth into diverse classes of materials for a broad range of energetic incident electrons (10 MeV, with better than 20% accuracy). The penetration depth—or range—of a material describes the maximum distance electrons can travel through a material, before losing all of its incident kinetic energy. This model has started to predict a …

Predictive Formula For Electron Range Over A Large Span Of Energy, Anne C. Starley, Jr Dennison

Senior Theses and Projects

A model developed by the Materials Research Group that calculates electron penetration range of some common materials, has been greatly expanded with the hope that such extensions will predict the range in other, perhaps, more interesting materials. Developments in this extended model aid in predicting the approximate penetration depth into diverse classes of materials for a broad range of energetic incident electrons (<10 eV to>10 MeV, with better than 20% accuracy). The penetration depth—or range—of a material describes the maximum distance electrons can travel through a material, before losing all of its incident kinetic energy. This model has started to predict …

Differentialgeometry In Brno, Ian M. Anderson

Presentations

This page will provide files supporting Ian Anderson's presentations in Brno, December 2015. The files can be found and downloaded from "Additional Files", below.

The files include:

(1) DifferentialGeometryUSU.mla: This is the Maple Library Archive file which provides all the DifferentialGeometry functionality. Here are Installation Instructions.

(2) DifferentialGeometry.help : this is the latest version of the DifferentialGeometry documentation. Copy this file to the same directory used for DifferentialGeometryUSU.mla (from step (1)).

Improving The Resilience Of Mixed-Farm Systems To Pending Climate Change In Far Western Nepal: Endline Survey Report, D. Layne Coppock

Environment and Society Faculty Publications

This report presents general findings from an endline survey carried out during May 2015 in Jugada, Budhiganga, Attichaur and Gudukhati Village Development Committees (VDCs) in Bajura District. A total of 320 households were surveyed, a total of 80 per VDC. Two of the VDCs—Jugada and Budhiganga—received capacity-building interventions for 16 months concerning climate-change adaptation, poverty reduction, and other aspects of well-being, while two VDCs—Attichaur and Gudkhati—were their "paired controls," respectively, that did not receive interventions. The interventions were largely delivered as informal educational or training modules.

Modelling Water Uptake Provides A New Perspective On Grass And Tree Coexistence, Michael G. Mazzacavallo, Andrew Kulmatiski

Wildland Resources Faculty Publications

Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize …