Physical Sciences and Mathematics Commons^™

Modulation Of The Semi-Annual Oscillation By Stratospheric Sudden Warmings As Seen In The High-Altitude Jawara Re-Analyses, Jiarong Zhang, Yvan Orsolini, Kaoru Sato

All Physics Faculty Publications

The semi-annual oscillation (SAO) dominates seasonal variability in the equatorial stratosphere and mesosphere. However, the seasonally dependent modulation of the SAO in the stratosphere (SSAO) and mesosphere (MSAO) by sudden stratospheric warmings (SSWs) in the Arctic has not been investigated in detail. In this study, we examine the seasonal evolution of the SAO during 16 major SSW events spanning 2004 to 2024 using the Japanese Atmospheric General Circulation Model for Upper Atmosphere Research Data Assimilation System Whole Neutral Atmosphere Re-analysis (JAWARA). Basic features of the SAO are well captured by JAWARA, as evidenced by the SSAO and MSAO appearing at …

Effects Of Radiation Type On Charge Transport In Aged Polymers, Zachary J. Gibson, Jr Dennison, Virginie Griseri

Journal Articles

Spacecraft charging issues are often investigated with simulated space environments and evaluated on pass–fail criteria that may yield little or no information about materials’ properties. It is far more effective to understand and mitigate spacecraft charging issues through investigations of material properties. However, material properties are dynamic in the harsh environment of space. Approximations must be made to simulate the space environment in the laboratory. This article reports on the investigation of the approximation that energy deposition causes the same aging effects in materials irrespective of the type of radiation sources. Samples of polytetrafluoroethylene (PTFE) and polyether-etherketone (PEEK) were irradiated …

Effect Of Space Radiation On The Mechanical Properties Of High-Strength Polyethylene Nanocomposite Films, Seunghyun Moon, Achal Duhoon, Zhongtian Gu, Jr Dennison, Tengfei Luo

Journal Articles

This study experimentally investigates the effects of prolonged radiation exposure on mechanical properties of high-strength, highly crystalline polyethylene (PE)/thermally reduced graphene oxide (TrGO) nanocomposite films for space applications. Prior to irradiation, PE/TrGO films were found to have tensile strengths up to ~4 GPa, more than 40 times that of conventional space-deployed membrane films (e.g., those used in solar sails) and over 59× the specific tensile strength. The PE/TrGO films were subjected to three radiation conditions to simulate space environmental conditions: ⁹⁰Sr beta radiation (0.2 to 2.5 MeV), 80 keV electron beam irradiation, and 4.9 eV ultraviolet (254 nm) exposure. …

Retaining The Herd: Habitat Restoration Efforts Increase Patch Retention Times In Mule Deer, Jack Rasmussen

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Across much of their range, and the State of Utah, mule deer (Odocoileus hemionus) populations have been declining. Declines in herd numbers can be attributed to alterations to historic habitats through the introduction of exotic annual grasses and the encroachment of pinyon-juniper forests on sagebrush ecosystems, changing resource availability. To combat habitat alterations, the Utah Department of Natural Resources has implemented various habitat restoration treatments through the Watershed Restoration Initiative , broadly to remove exotic species and decrease pinyon juniper woodland encroachment. We investigated how mule deer patch retention times differ on eight different habitat restoration treatment types during summer …

Site Specific Reliability-Targeted Snow Loads And Winter Wind Parameters Across The World, Brennan Bean, Nicholas Brimhall, Bikram Bhusal, Marc Maguire, Maha Moussa

Mathematics and Statistics Faculty Publications

This report presents a framework for estimating Reliability Targeted Snow Loads (RTSLs) and Winter Wind Parameters (WWPs) at locations outside the Conterminous United States (OCONUS). The methodology integrates ground-based in-situmeasurements with gridded global climate products to generate spatially continuous RTSL estimates for nearly any location in OCONUS. RTSLs are computed at qualifying in-situ stations, and predictive models relating gridded climate products to in-situRTSLs enable estimation at locations lacking direct measurements. This report describes the development of the in-situ annual maximum snow load database, the construction of global gridded climate summaries, the estimation of site-specific RTSLs and Service Targeted …

Energy Input-Output Meta-Analysis Reveals Algal Diesel Struggles To Break Even (Supplemental Information), Michelle Arnold

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1. Algal biofuels have been investigated as an alternative to traditional fossil fuels for transportation in the United States since the 1970s. Yet after five decades of development, scalability and implementation remain limited. To evaluate the state of progress, this study harmonized energy inputs and outputs across 39 papers, encompassing 508 observations on the production of algal biofuel energy return on energy investment (EROEI) in the United States. The analysis produced a mean EROEI of 1.01—essentially the break-even point—irrespective of system boundaries. This is lower than bioethanol (2.8) and far below oil (8.7). Life-cycle analysis results showed that hydrothermal liquefaction in …

Increasing Complexity Leads To Declining Productivity Of Innovation In The Algal Biofuel Industry (Supplemental Information), Michelle Arnold

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Liquid biofuels are widely promoted as renewable, lower-emission alternatives to fossil fuels. Yet despite their promise, this sector faces a critical constraint: a long-term decline in the productivity of innovation. This decline—measured by a decreasing number of patents per inventor—suggests that generating technological breakthroughs is becoming more difficult, expensive, and uncertain. As innovation becomes more resource-intensive, the feasibility of replacing petroleum with liquid biofuels grows more tenuous. This is especially problematic given the pre-existing technical disadvantages of biofuels, including their relatively low energy return on energy investment (EROEI) and energy density compared to fossil fuels. Our findings show that the …

Data Accompanying "Landscape Composition Surrounding Restoration Projects Modulates Use By Wildlife: A Case Study Of Mule Deer In Utah", Jaylin Solberg

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With mule deer (Odocoileus hemionus), hereafter, deer, populations in decline, wildlife managers have increased their efforts to improve factors that limit population growth. In the State of Utah (hereafter, Utah), these efforts have included habitat restoration which is expected to improve environmental conditions for deer. Some of these efforts include pinon-juniper removal, prescribed burning, and spraying of invasive plant species. Although previous work has demonstrated the local impacts of restoration on deer populations, it is unknown how the environmental conditions in the landscape surrounding restoration treatments may modify local restoration impacts. Identifying how both local and landscape-scale conditions influence deer …

A Guide To Breaking Seed Dormancy Of Common Wetland Plant Species, Samantha R. Kurkowski, Rae Robinson, Sandra E. Johnston, Montana M. Horchler, Adrienne E. Ernst, Margaret D. Haney, Karin M. Kettenring

All Current Publications

This guide was developed from a series of seed dormancy break and germination experiments conducted over 4 years with 41 species. The purpose of this guide is to synthesize the information we learned through these experiments and present the findings for those interested in breaking seed dormancy, such as land managers, restoration practitioners, and wetland researchers. Ultimately, we hope this guidance catalyzes further wetland restoration throughout the Intermountain West.

Reliability Targeted Snow Loads And Winter Wind Parameters For Locations Outside Of The Conterminous United States, Brennan L. Bean, Nicholas Brimhall, Bikram Bhusal, Marc Maguire, Maha Moussa

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The national building standard ASCE 7 moved to reliability-targeted snow loads (RTSLs) in the 2022 version. This necessitates the development of RTSLs for international locations. This repository contains the data and code needed to produce RTSLs and Winter Wind Parameters for locations outside of the Conterminous United States (OCONUS). It relies on annual maximum snow loads provided in a separate data release (see Brimhall et al. 2025).

Electron Yields Of Lunar Regolith Simulant Layers, Christopher Vega, Matthew Robertson, Thomas Keaton, Heather Allen, Jr Dennison

Journal Articles

The charging of bulk lunar regolith has been recognized since the Apollo era as an immediate and critical issue facing our return to the moon. Accurate electron yield (EY) measurements of bulk highly insulating granular materials—which largely determine how such particles charge through interactions with space environments—are lacking due to many experimental complexities that have led to a critical knowledge gap. Such knowledge is essential for addressing fundamental science and myriad important lunar applications and simulations related to lunar dust and regolith electrostatic charging. The few prior EY studies of lunar dust were limited due to severe charging effects and …

Cloud Seeding: Enhancing Winter Snowpack To Bolster Utah's Water Supply, Lily Lambert, Kendall Becker, Binod Pokharel, Scott Hotaling

All Current Publications

As Utah’s climate warms, the state is working to combat the decline in winter snowpack caused by rising temperatures. Cloud seeding is a safe technology that, under the right conditions, can boost snowfall. In this fact sheet, we describe what cloud seeding is, where it is currently used in Utah, and the safety measures and management practices that ensure its responsible use.

Eutrophication, Hope Northagen, Sarah Erwin, Ethan Gilliam

All Current Publications

Eutrophication refers to the ecological state of a water body after excessive nutrient pollution. The external introduction of nutrients (primarily nitrogen and phosphorus) accelerates the growth and reproduction of plants, algae, and microbes. This fact sheet explains where eutrophication comes from, its impacts, how it is treated, and what you can do to help restore and protect our lakes, rivers, and oceans.

Improved Streamflow Forecasting Through Swe-Augmented Spatio-Temporal Graph Neural Networks, Akhila Akkala, Soukaina Filali Boubrahimi, Shah Muhammad Hamdi, Pouya Hosseinzadeh, Ayman Nassar

Computer Science Student Research

Streamflow forecasting in snowmelt-dominated basins is essential for water resource planning, flood mitigation, and ecological sustainability. This study presents a comparative evaluation of statistical, machine learning (Random Forest), and deep learning models (Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU), and Spatio-Temporal Graph Neural Network (STGNN)) using 30 years of data from 20 monitoring stations across the Upper Colorado River Basin (UCRB). We assess the impact of integrating meteorological variables—particularly, the Snow Water Equivalent (SWE)—and spatial dependencies on predictive performance. Among all models, the Spatio-Temporal Graph Neural Network (STGNN) achieved the highest accuracy, with a Nash–Sutcliffe Efficiency (NSE) of 0.84 …

Interface Catalysts Of In Situ-Grown Tio2/Mxenes For High-Faraday-Efficiency Co2 Reduction, Shaun Debow, Zichen Shen, Arjun Sathyan Kulathuvayal, Fuzhan Song, Tong Zhang, Haley Fisher, Jesse B. Brown, Yuqin Qian, Zhi-Chao Huang-Fu, Hui Wang, Zachary Zander, Mark S. Mirotznik, Robert L. Opila, Yanqing Su, Yi Rao

Chemistry and Biochemistry Student Research

Climate change and the global energy crisis have led to an increasing need for greenhouse gas remediation and clean energy sources. The electrochemical CO₂ reduction reaction (CO₂RR) is a promising solution for both issues as it harvests waste CO₂ and chemically reduces it to more useful forms. However, the high overpotential required for the reaction makes it electrochemically unfavorable. Here, we fabricate a novel electrode composed of TiO₂ nanoparticles grown in situ on MXene charge acceptor 2D sheets with excellent CO₂RR characteristics. A straightforward solvothermal method was used to grow the nanoparticles on …

Chemical Analyses Of Grass Samples, Johan Du Toit, Shantell Garrett

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Results of chemical analyses of grass samples collected in the foothills of the Henry Mountains, south-central Utah, in the fall of 2021.

Plant Biomass (Dry) Per Square Meter, Johan Du Toit, Shantell Garrett

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Results of plant biomass clippings (dry mass / square meter) conducted in the foothills of the Henry Mountains, south-central Utah, over 2012-2022.

Chemical Analyses Of Soil Samples, Johan Du Toit, Shantell Garrett

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Results of chemical analyses of soil collected in the foothills of the Henry Mountains, south-central Utah, in the fall of 2020.

Time-Dependent Radiation Induced Conductivity Of Polyimide: Effects Of Dose Rate And Temperature On Dynamic Ric, Tyler Heggenes, Jenny R. Whiteley, Jodie Gillespie, Jr Dennison

Journal Articles

Radiation induced conductivity (RIC) can impact charge dissipation within highly insulating materials used in spacecraft in harsh space plasma environments. Previous Utah State University (USU) research analyzed only the equilibrium portions of an extensive RIC database for polymeric materials, including Kapton HN (Trademark). This confirmed that equilibrium RIC follows a standard theoretical model that is temperature and dose rate dependent. The current study provides a new analysis of RIC’s time-dependent behavior of the Kapton HN data from this database. With the onset of radiation, the material response is characterized by an exponential increase in conductivity, while a hyperbolic inverse time-dependent …

Lagomorph Spotlight Survey Results, Johan Du Toit, Shantell Garrett

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Results of lagomorph spotlight surveys conducted in the foothills of the Henry Mountains, south-central Utah, over 2014-2022.

Analytical Solutions For Transitional Flow Around Hydrometeors: Implications For Particle Dynamics And Atmospheric Modeling, Ahmad Talaei, Timothy J. Garrett

Physics Student Research

Accurate modeling of hydrometeor dynamics is critical for advancing weather and climate predictions. However, this remains a long-standing challenge in atmospheric science, particularly within the transitional Reynolds number regime, due to the lack of analytical solutions to the Navier–Stokes equations. This study presents two analytical solutions for two-dimensional, incompressible, and viscous flow around a sphere, addressing the gap between low and high Reynolds number regimes. The first framework, an extension of classical expansion methods using hypergeometric, provides a direct analytical relation that characterizes separation angle across the transitional regime. To address post- separation dynamics, a second formulation based on a …

Creating Wildfire-Resilient Communities In Utah: Fuel Treatments In The Wildland-Urban Interface, Luke Dutson, Kendall Becker, Katlyn Stemmler, J. Bradley Washa, Larissa L. Yocom Kent, Aish Chandrasekaran, Joseph D. Birch, Scott Hotaling

All Current Publications

In the western United States, decades of wildfire suppression and grazing have led to changes in the amount and type of wildland fuels. In many lower montane forests, fuels such as logs, dead trees, and fallen leaves have accumulated. In many sagebrush-dominated rangelands, annual grasses have invaded, and pinyon pine and juniper woodlands have encroached. These areas now threaten to burn at uncharacteristically high fire severity, a metric based on how much vegetation is killed. Climate change and rapid population growth have exacerbated this issue in Utah, increasing the threat wildfire poses to the state’s communities, infrastructure, and ecosystems. Fuel …

Eng- Semicon: Understanding Nanoscale Heat Transport In Wide- And Ultrawide Bandgap Semiconductors Using Novel Deep Ultraviolet Tools, Joshua Lee Knobloch

Funded Research Records

No abstract provided.

Reeds Run Amok: A Practical Guide To Managing Phragmites-Invaded Wetlands, Christine Rohal, Keith Hambrecht, Chad Cranney, Karin M. Kettenring

All Current Publications

Phragmites australis (common reed or simply “phragmites”) is a tall-statured, highly productive wetland grass. It spreads rapidly, often displacing native plants and degrading critical habitat for shorebirds and waterfowl by reducing the availability of nesting, loafing, and foraging areas. Phragmites also consumes large amounts of water, adding pressure to already scarce water resources. Additionally, the accumulation of standing dead biomass can be a fire hazard. Phragmites makes large areas of wetlands inaccessible to both wildlife and humans. This guide provides guidance on managing phragmites.

Structural Evolution Of Nitrogenase Over 3 Billion Years, Bruno Cuevas Zuviría, Franka Detemple, Kaustubh Amritkar, Amanda K. Garcia, Lance Seefeldt, Betül Kaçar

Chemistry and Biochemistry Faculty Publications

Previously, we identified the only dinitrogen reduction mechanism known to date as an ancient feature conserved from nitrogenase ancestors, which we directly tested by resurrecting and integrating synthetic ancestral nitrogenases into the genome of Azotobacter vinelandii (Garcia et al., 2023), a genetically tractable, nitrogen-fixing model bacterium. Here, we extend this paleomolecular approach to investigate the structural evolution of nitrogenase over billions of years of evolution by combining phylogenetics, ancestral sequence reconstruction, protein crystallography, and deep-learning based predictions. This study reveals that nitrogenase, while maintaining a conserved multimeric core, evolved novel modular features aligned with major environmental transitions, suggesting that subtle …

Sagebrush, Wildfire, And Homeowners Associations: Climate Adaptation Opportunities In Summit County, Utah, Rebecca Ivans, Kendall Becker, Wesley Crump, J. Bradley Washa, Lewis Kogan, Scott Hotaling

All Current Publications

Environmental changes and rapidly expanding suburban developments are amplifying wildfire risk in Utah, including in mixed-sagebrush habitats like those in Morgan, Summit, and Wasatch counties along the Wasatch Back. Wildfire risk to people and structures is especially high in the wildland-urban interface (WUI), where homes and buildings intermingle with undeveloped wildlands and natural vegetation that can fuel wildfire. Much of this urban expansion is occurring in the form of large, dispersed developments managed by homeowners associations (HOAs), which often dictate standards for the homes and properties within their purview. Thus, HOAs can play a critical role in supporting wildfire mitigation …

The Next Frontier In The Study Of Noncovalent Bonding: Transition Metals, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

As work continues unabated in the study of noncovalent bonding, particularly σ-hole bonds, new challenges have emerged as the participation of transition metals in interactions of this sort is fast becoming appreciated. While there are certain similarities with the halogen, chalcogen, etc, bonds, in which the main group elements participate, there are certain unique properties of these metal atoms that must be analyzed before a complete understanding can be attained. As one example, these atoms tend to act simultaneously as both electron donors and acceptors, a synergistic action that amplifies the overall bond strength. Ideas are expressed in this paper …

Reconstruction Of Water Storage Variability In The Aral Sea Region, Nikita Murzintcev, Sahibjamal Nietullaeva, Timur Berdimbetov, Buddhi Pushpawela, Asiya Tureniyazova, Sherly Shelton, Bakbergen Aytmuratov, Khusen Gafforov, Kanat Parakhatov, Alimjan Erdashov, Abdul-Aziz Makhamatdinov, Timur Allamuratov

Plants, Soils and Climate Student Research

The Gravity Recovery and Climate Experiment (GRACE) mission, operational from 2002 to 2017, provided critical measurements of Earth's gravity field anomalies which have been extensively used to study groundwater and terrestrial water storage (TWS) dynamics. In this research, we utilize GRACE data to identify, model, and analyze potential climate parameters contributing to the reconstruction of TWS variability in the Aral Sea Basin region (ASB). We assess the impact of climate change and anthropogenic nature management on TWS change using a quantitative method. Our analysis reveals a significant decline in the TWS at a rate of 0.44 cm year^-1 during …

Reducing Residential Landscape Water Use In Utah: Technologies And Strategies, Maya Cottam, Kendall Becker, Katlyn Stemmler, Shital Poudyal, Wesley Crump, Lewis Kogan, Scott Hotaling

All Current Publications

Water conservation is a critical issue in Utah, and several actions are already underway to help lower residential landscape water use. Strategies include smart irrigation controllers, efficient sprinkler bodies and nozzles, drip irrigation systems, soil amendments that increase water-holding capacity, and drought-tolerant grass cultivars for lawns. While additional conservation efforts will be necessary to reach sustainable water management, statewide adoption of current programs can help reduce water use and loss.

Large-Scale Flood Detection And Mapping In The Yangtze River Basin (2016–2021) Using Convolutional Neural Networks With Sentinel-1 Sar Images, Xuan Wu, Zhijie Zhang, Wanchang Zhang, Bangsheng An, Zhenghao Li, Rui Li, Qunli Chen

Environment and Society Faculty Publications

Synthetic Aperture Radar (SAR) technology offers unparalleled advantages by delivering high-quality images under all-weather conditions, enabling effective flood monitoring. This capability provides massive remote sensing data for flood mapping, while recent rapid advances in deep learning (DL) offer methodologies for large-scale flood mapping. However, the full potential of deep learning in large-scale flood monitoring utilizing remote sensing data remains largely untapped, necessitating further exploration of both data and methodologies. This paper presents an innovative approach that harnesses convolutional neural networks (CNNs) with Sentinel-1 SAR images for large-scale inundation detection and dynamic flood monitoring in the Yangtze River Basin (YRB). An …