Physical Sciences and Mathematics Commons^™

Gender And Environmental Sustainability: A Cross-National Analysis On Political Representation Of Women And Subsequent State Sustainability, Erin O'Sullivan

Department of Environmental Studies: Undergraduate Student Theses

The literature focusing on the relationship between gender and environmental sustainability is vast. Research has focused on how gender relates to pro-sustainable behavior but fails to analyze this beyond individual action. Research has also found positive correlations between women’s representation at a state’s political level and different factors of state sustainability. However, literature has fallen short on analyzing if there is a causal effect between these factors. This study aimed to fill this gap in the literature and analyzes how the ratio of women in parliament in a state affects the state’s environmental sustainability. Although the results showed no statistically …

Regenerative Agriculture –A Pathway For Addressing Nebraska’S Water Quality And Soil Degradation Challenges, Kjersten Hyberger

Department of Environmental Studies: Undergraduate Student Theses

It is important to begin this thesis by acknowledging that the State of Nebraska is on stolen Native land. Furthermore, the University of Nebraska is a land-grant university that was ultimately given 89,920 acres of Native lands for the paltry sum of $11,194. To date, the University of Nebraska has benefited from a 51:1 profit ratio on the funds raised from its 1873 land grant, raising over $500,000 in endowment principle. I humbly acknowledge that the privilege of earning my degree at UNL came through the often violent and bloody displacement of multiple tribal nations (High Country News, 2020).

Examining The Psychology And Human Behavior Of Sustainable Living: The Impact Of Socioeconomic Status On Climate Change Education, Samantha Nielsen

Department of Environmental Studies: Undergraduate Student Theses

Climate change education has become increasingly important as the world faces the challenges of a rapidly changing environment. However, not all individuals have equal access to this education, and socioeconomic status has been identified as a barrier to climate change knowledge. This thesis explores the impact of socioeconomic status on climate change education through a survey-based approach, using the Nebraska Annual Social Indicators Survey to investigate the relationship between income and degree of education with climate change concern and community interaction. The study finds a significant correlation between higher levels of education and climate change concern, as well as greater …

Solar Energy Implementation In Rural Communities, Corie Gleason

Department of Environmental Studies: Undergraduate Student Theses

This thematic analysis was completed in Nebraska, as it looked at how the state’s rural communities react to solar energy projects. Due to their strong sense of social and community identity, members of rural communities are often resistant to change and may have difficulty supporting new projects such as solar farms in their communities. However, these rural communities provide the necessary space for solar farms while still being in close proximity to the users of the energy that the farms produce. This study aims to explore what factors have made past solar projects successful and the ways in which those …

Impact Of The Covid-19 Pandemic On Nebraska State Park Visitation, Bailey Mullins

Department of Environmental Studies: Undergraduate Student Theses

The Covid-19 virus was declared a pandemic on March 11, 2020 by the World Health Organization. Since then the outdoor recreation habits of the general public have changed due to the constraints and risks of the virus. The first case of Covid-19 in Nebraska was reported in March of 2020. One of the most popular places for recreation in the state of Nebraska is to visit our state parks and recreation areas. The purpose of this research is to determine how the Covid-19 pandemic has impacted visitation at Nebraska state parks and recreation areas. To do this, the Nebraska Game …

Rails To Trails Program: Neighborhood Dynamics In Lincoln, Nebraska, Emma Mccormick

Department of Environmental Studies: Undergraduate Student Theses

As cities increasingly move towards creating sustainable, equitable, climate-forward communities, city planners, advocates, and policymakers have begun to focus increasingly on improving access to greenspaces. Studies around the globe have documented the importance of greenspace for multiple individual, group, and community level outcomes. Simultaneously, extant research suggests that access to greenspaces frequently reflects social inequality in urban spaces, stratifying such access by race and socioeconomic composition of neighborhoods. However, few research projects have examined potential unintended consequences, such as contemporary housing issues like gentrification, that greenspaces can create for community infrastructure here in Lincoln, Nebraska.

Studying Developer Eye Movements To Measure Cognitive Workload And Visual Effort For Expertise Assessment, Salwa D. Aljehane, Bonita Sharif, Jonathan I. Maletic

School of Computing: Faculty Publications

Eye movement data provides valuable insights that help test hypotheses about a software developer’s comprehension process. The pupillary response is successfully used to assess mental processing effort and attentional focus. Relatively little is known about the impact of expertise level in cognitive effort during programming tasks. This paper presents a quantitative analysis that compares the eye movements of 207 experts and novices collected while solving program comprehension tasks. The goal is to examine changes of developers’ eye movement metrics in accordance with their expertise. The results indicate significant increase in pupil size with the novice group compared to the experts, …

Examining The Effect Of Word Embeddings And Preprocessing Methods On Fake News Detection, Jessica Hauschild

Department of Statistics: Dissertations, Theses, and Student Work

The words people choose to use hold a lot of power, whether that be in spreading truth or deception. As listeners and readers, we do our best to understand how words are being used. There are many current methods in computer science literature attempting to embed words into numerical information for statistical analyses. Some of these embedding methods, such as Bag of Words, treat words as independent, while others, such as Word2Vec, attempt to gain information about the context of words. It is of interest to compare how well these various methods of translating text into numerical data work specifically …

Assessment Of Bridge Pier Response To Fire, Vehicle Impact, And Air Blast, Chen Fang, Qusai Alomari, Daniel G. Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system …

Sim-To-Real Reinforcement Learning Framework For Autonomous Aerial Leaf Sampling, Ashraful Islam

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Using unmanned aerial systems (UAS) for leaf sampling is contributing to a better understanding of the influence of climate change on plant species, and the dynamics of forest ecology by studying hard-to-reach tree canopies. Currently, multiple skilled operators are required for UAS maneuvering and using the leaf sampling tool. This often limits sampling to only the canopy top or periphery. Sim-to-real reinforcement learning (RL) can be leveraged to tackle challenges in the autonomous operation of aerial leaf sampling in the changing environment of a tree canopy. However, trans- ferring an RL controller that is learned in simulation to real UAS …

Leveraging Aruco Fiducial Marker System For Bridge Displacement Estimation Using Unmanned Aerial Vehicles, Mohamed Aly

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

The use of unmanned aerial vehicles (UAVs) in construction sites has been widely growing for surveying and inspection purposes. Their mobility and agility have enabled engineers to use UAVs in Structural Health Monitoring (SHM) applications to overcome the limitations of traditional approaches that require labor-intensive installation, extended time, and long-term maintenance. One of the critical applications of SHM is measuring bridge deflections during the bridge operation period. Due to the complex remote sites of bridges, remote sensing techniques, such as camera-equipped drones, can facilitate measuring bridge deflections. This work takes a step to build a pipeline using the state-of-the-art computer …

Theory Of Invariant Manifold And Foliation And Uniqueness Of Center Manifold Dynamics, Bo Deng

Department of Mathematics: Faculty Publications

Here we prove that the dynamics on any two center-manifolds of a fixed point of any C^k,1 dynamical system of finite dimension with k ≥ 1 are C^k-conjugate to each other. For pedagogical purpose, we also extend Perron’s method for differential equations to diffeomorphisms to construct the theory of invariant manifolds and invariant foliations at fixed points of dynamical systems of finite dimensions.

The Influence Of The Substrate On The Functionality Of Spin Crossover Molecular Materials, Saeed Yazdani, Jared Phillips, Thilini K. Ekanayaka, Ruihua Cheng, Peter A. Dowben

Department of Physics and Astronomy: Faculty Publications

Spin crossover complexes are a route toward designing molecular devices with a facile readout due to the change in conductance that accompanies the change in spin state. Because substrate effects are important for any molecular device, there are increased efforts to characterize the influence of the substrate on the spin state transition. Several classes of spin crossover molecules deposited on different types of surface, including metallic and non-metallic substrates, are comprehensively reviewed here. While some non-metallic substrates like graphite seem to be promising from experimental measurements, theoretical and experimental studies indicate that 2D semiconductor surfaces will have minimum interaction with …

Stabilizing Polar Phases In Binary Metal Oxides By Hole Doping, Tengfei Cao, Guodong Ren, Ding-Fu Shao, Evgeny Y. Tsymbal, Rohan Mishra

Department of Physics and Astronomy: Faculty Publications

The recent observation of ferroelectricity in the metastable phases of binary metal oxides, such as HfO₂, ZrO₂, Hf_0.5Zr_0.5O₂, and Ga₂O₃, has garnered a lot of attention. These metastable ferroelectric phases are typically stabilized using epitaxial strain, alloying, or defect engineering. Here, we propose that hole doping plays a key role in the stabilization of polar phases in binary metal oxides. Using first-principles density-functional-theory calculations, we show that holes in these oxides mainly occupy one of the two oxygen sublattices. This hole localization, which is more pronounced …

Climate-Controlled Submarine Landslides On The Antarctic Continental Margin, Jenny A. Gales, Robert M. Mckay, Laura De Santis, Michele Rebesco, Jan Sverre Laberg, Amelia E. Shevenell, David M. Harwood, R. Mark Leckie, Denise K. Kulhanek, Maxine King, Molly Patterson, Renata G. Lucchi, Sookwan Kim, Sunghan Kim, Justin Dodd, Julia Seidenstein, Catherine Prunella, Giulia M. Ferrante, Iodp Expedition

Department of Earth and Atmospheric Sciences: Faculty Publications

Antarctica’s continental margins pose an unknown submarine landslidegenerated tsunami risk to Southern Hemisphere populations and infrastructure. Understanding the factors driving slope failure is essential to assessing future geohazards. Here, we present a multidisciplinary study of a major submarine landslide complex along the eastern Ross Sea continental slope (Antarctica) that identifies preconditioning factors and failure mechanisms. Weak layers, identified beneath three submarine landslides, consist of distinct packages of interbedded Miocene- to Pliocene-age diatom oozes and glaciomarine diamicts. The observed lithological differences, which arise from glacial to interglacial variations in biological productivity, ice proximity, and ocean circulation, caused changes in sediment deposition …

Permian Trilobites And The Applicability Of The “Living Fossil” Concept To Extinct Clades, Melanie J. Hopkins, Peter Wagner, Katherine J. Jordan

Department of Earth and Atmospheric Sciences: Faculty Publications

Some taxa occupy our imaginations as “living fossils” because they were known from the fossil record before being discovered alive today. Other taxa are considered “living fossils” because modern relatives bear a strong morphological resemblance to fossil relatives, or because they occupy a contracted geographic range or have less diversity now than in the past, or because they represent phylogenetic diversity that requires conservation. A characterizing feature of living fossils–and thus an implicit assumption of all criteria–is that the “living fossil” of interest is extant. However, the general research questions that “living fossils” inspire–Why do rates of evolution vary across …

Science Club, Danielle Gibson, Krista Andersen

Honors Expanded Learning Clubs

Honors After School program for elementary age children to engage with scientific principles. Students performed hands-on experiments to explore various STEM fields. Each weekly lesson consisted of a different concept to be learned or explored by early elementary aged students.

How Resilience Is Framed Matters For Governance Of Coastal Social-Ecological Systems, Sarah Clement, Javad Jozaei, Michael Mitchell, Craig R. Allen, Ahjond S. Garmestani

School of Natural Resources: Faculty Publications

Effective governance of social-ecological systems (SES) is an enduring challenge, especially in coastal environments where accelerating impacts of climate change are increasing pressure on already stressed systems. While resilience is often proposed as a suitable framing to re-orient governance and management, the literature includes many different, and sometimes conflicting, definitions and ideas that influence how the concept is applied, especially in coastal environments. This study combines discourse analysis of the coastal governance literature and key informant interviews in Tasmania, Australia, demonstrating inconsistencies and confusion in the way that resilience is framed in coastal governance research and practice. We find that …

Towards A Global Sustainable Development Agenda Built On Social–Ecological Resilience, Murray W. Scown, Robin K. Craig, Craig R. Allen, Lance Gunderson, David G. Angeler, Jorge H. Garcia, Ahjond Garmestani

School of Natural Resources: Faculty Publications

Non-technical summary. The United Nations’ sustainable development goals (SDGs) articulate societal aspirations for people and our planet. Many scientists have criticised the SDGs and some have suggested that a better understanding of the complex interactions between society and the environment should underpin the next global development agenda. We further this discussion through the theory of social–ecological resilience, which emphasises the ability of systems to absorb, adapt, and transform in the face of change. We determine the strengths of the current SDGs, which should form a basis for the next agenda, and identify key gaps that should be filled.

Technical …

The Spin Polarization Of Palladium On Magneto-Electric Cr2O3, Takashi Komesu, Will Echtenkamp,, Christian H. Binek, Peter A. Dowben

Department of Physics and Astronomy: Faculty Publications

While induced spin polarization of a palladium (Pd) overlayer on antiferromagnetic and magneto-electric Cr₂O₃(0001) is possible because of the boundary polarization at the Cr₂O₃(0001), in the single domain state, the Pd thin film appears to be ferromagnetic on its own, likely as a result of strain. In the conduction band, we find the experimental evidence of ferromagnetic spin polarized in Pd thin films on a Cr₂O₃(0001) single crystal, especially in the thin limit, Pd thickness of around 1–4 nm. Indeed there is significant spin polarization in 10 Å …

Deficit Irrigation Management For Irrigated Corn In Nebraska: Economically Viable?, Lia Nogueira, Cory Walters, Emily O'Donnell, Wesley Peterson, Suat Irmak

Cornhusker Economics

In this study we determine the economic value of deficit irrigation management using both technological and methodological advancements. The use of soil moisture probes represents the technological improvement. We provide improvements in the methodology as follows. Regarding data, we employ a field-size study, instead of plots, where the irrigation decision is determined by the moisture level in the soil measured through a soil moisture probe. Regarding the understanding of the yield response to water, although we examine the commonly used quadratic function, we improve upon this specification by also examining an alternative response function, the linear response stochastic plateau. Our …

Spot-Fire Distance Increases Disproportionately For Wildfires Compared To Prescribed Fires As Grasslands Transition To Juniperus Woodlands, Victoria M. Donovan, Dillon T. Fogarty, Dirac L. Twidwell Jr

School of Natural Resources: Faculty Publications

Woody encroachment is one of the greatest threats to grasslands globally, depleting a suite of ecosystem services, including forage production and grassland biodiversity. Recent evidence also suggests that woody encroachment increases wildfire danger, particularly in the Great Plains of North America, where highly volatile Juniperus spp. convert grasslands to an alternative woodland state. Spot-fire distances are a critical component of wildfire danger, describing the distance over which embers from one fire can cause a new fire ignition, potentially far away from fire suppression personnel. We assess changes in spot-fire distances as grasslands experience Juniperus encroachment to an alternative woodland state …

E6 Models In Light Of Precision MW Measurements, Vernon Barger, Cash Hauptmann, Peisi Huang, Wai-Yee Keung

Department of Physics and Astronomy: Faculty Publications

We propose a solution to the recent W mass measurement by embedding the Standard Model within E₆ models. The presence of a new U(1) group shifts the W boson mass at the tree level and introduces a new gauge boson Z' which has been searched for at collider experiments. In this article, we identify the parameter space that explains the new W mass measurement and is consistent with current experimental Z' searches. As U(1) extensions can be accommodated in supersymmetric models, we also consider the supersymmetric scenario of E₆ models, and show that a 125 GeV …

Convolutional Neural Networks Analysis Reveals Three Possible Sources Of Bronze Age Writings Between Greece And India, Shruti Daggumati, Peter Z. Revesz

School of Computing: Faculty Publications

This paper analyzes the relationships among eight ancient scripts from between Greece and India. We used convolutional neural networks combined with support vector machines to give a numerical rating of the similarity between pairs of signs (one sign from each of two different scripts). Two scripts that had a one-to-one matching of their signs were determined to be related. The result of the analysis is the finding of the following three groups, which are listed in chronological order: (1) Sumerian pictograms, the Indus Valley script, and the proto-Elamite script; (2) Cretan hieroglyphs and Linear B; and (3) the Phoenician, Greek, …

Test 2240: Kubota M8-231, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nash Blowups Of Toric Varieties In Prime Characteristic, Daniel Duarte, Jack Jeffries, Luis Núñez-Betancourt

Department of Mathematics: Faculty Publications

We initiate the study of the resolution of singularities properties of Nash blowups over fields of prime characteristic. We prove that the iteration of normalized Nash blowups desingularizes normal toric surfaces. We also introduce a prime characteristic version of the logarithmic Jacobian ideal of a toric variety and prove that its blowup coincides with the Nash blowup of the variety. As a consequence, the Nash blowup of a, not necessarily normal, toric variety of arbitrary dimension in prime characteristic can be described combinatorially.

Test Beam Performance Of A Cbc3-Based Mini-Module For The Phase-2 Cms Outer Tracker Before And After Neutron Irradiation, Cms Collaboration

Department of Physics and Astronomy: Faculty Publications

The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5 × 10³⁴ cm^-2s^-1. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb^-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the …

A Method To Measure Positron Beam Polarization Using Optically Polarized Atoms, Joshua Joshua Machacek, Sean Hodgman, Stephen Buckman, T. J. Gay

Department of Physics and Astronomy: Faculty Publications

We outline an experimental technique for measuring the degree of polarization of a positron beam using an optically pumped, spin-polarized Rb target. The technique is based on the production and measurement of the ortho- and para-positronium fractions through positron collisions with the Rb atoms as a function of their polarization. Using realistic estimates for the cross sections and experimental parameters involved, we estimate that a polarization measurement with an uncertainty of 3% of the measured value can be achieved in an hour

Water Current, Volume 55, No. 1, Spring 2023

Water Current Newsletter

No abstract provided.

Extremal Absorbing Sets In Low-Density Parity-Check Codes, Emily Mcmillon, Allison Beemer, Christine A. Kelley

Department of Mathematics: Faculty Publications

Absorbing sets are combinatorial structures in the Tanner graphs of low-density parity-check (LDPC) codes that have been shown to inhibit the high signal-to-noise ratio performance of iterative decoders over many communication channels. Absorbing sets of minimum size are the most likely to cause errors, and thus have been the focus of much research. In this paper, we determine the sizes of absorbing sets that can occur in general and left-regular LDPC code graphs, with emphasis on the range of b for a given a for which an (a, b)-absorbing set may exist. We identify certain cases of extremal …