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Articles 391 - 420 of 25791

Full-Text Articles in Physical Sciences and Mathematics

Development Of The Nebraska Department Of Transportation Winter Severity Index – Phase Ii, Mark Anderson, Curtis L. Walker, Thomas Kauzlarich May 2024

Development Of The Nebraska Department Of Transportation Winter Severity Index – Phase Ii, Mark Anderson, Curtis L. Walker, Thomas Kauzlarich

Nebraska Department of Transportation: Research Reports

For the Nebraska Department of Transportation (NDOT), the Nebraska Winter Severity Index (NEWINS) provided an independent framework to calculate a winter season’s severity by categorizing individual winter storms. However, one of the greatest limitations of NEWINS is that it is not predictive. Thus, this study builds on the previously developed NEWINS by creating a predictive winter storm severity index known as NEWINS-Predictive (NEWINS-P). The quantitative precipitation forecast, snow accumulation, ice accumulation, and surface wind speed parameters from the National Digital Forecast Database (NDFD) are used to develop the five components composing the NEWINS-P framework. These components consist of snow severity …


Plas 439: Organic Farming And Food Systems Faculty-Led Inquiry Into Reflective Scholarly Teaching Benchmark Portfolio, Christian Stephenson May 2024

Plas 439: Organic Farming And Food Systems Faculty-Led Inquiry Into Reflective Scholarly Teaching Benchmark Portfolio, Christian Stephenson

UNL Faculty Course Portfolios

Organic Farming and Food Systems is a senior and graduate level course for students in the Department of Agronomy and Horticulture. This course was previously offered but has been significantly modified as I have taken on responsibility for the course. Goals for the course include student comprehension of the methods of organic and regenerative farming and the impacts of those methods on economic, environmental, and social sustainability. An additional goal is to build student competency in the evaluation of primary, secondary, and tertiary information resources and critical thinking surrounding issues in food production. Assessment for the course was through diverse …


Morphometric Analysis And Taxonomic Re-Evaluation Of Pepsis Cerberus Lucas And P. Elegans Lepeletier (Hymenoptera: Pompilidae: Pepsinae: Pepsini), Frank E. Kurczewski, Akira Shimizu, Diane H. Kiernan May 2024

Morphometric Analysis And Taxonomic Re-Evaluation Of Pepsis Cerberus Lucas And P. Elegans Lepeletier (Hymenoptera: Pompilidae: Pepsinae: Pepsini), Frank E. Kurczewski, Akira Shimizu, Diane H. Kiernan

Insecta Mundi

Hurd (1952) separated Pepsis cerberus Lucas from P. elegans Lepeletier (Hymenoptera: Pompilidae: Pepsinae: Pepsini) based on external morphology and biogeography. Vardy (2005) synonymized the familiar and historically well-documented P. cerberus and P. elegans, combining these Nearctic taxa with several Neotropical variants in an extremely broad definition of P. menechma Lepeletier. In doing so, Vardy (2005) breached the principle of nomenclatural stability. He ignored the prevailing usage and clearly violated articles 23.2, 23.3 and 23.9.1.2 of the ICZN (1999). Morphological differences, ecological divergence, and narrow sympatric geographic distribution of P. cerberus and P. elegans …


Nonlinear Classifiers For Wet-Neuromorphic Computing Using Gene Regulatory Neural Network, Adrian Ratwatte, Samitha Somathilaka, Sasitharan Balasubramaniam, Assaf A. Gilad May 2024

Nonlinear Classifiers For Wet-Neuromorphic Computing Using Gene Regulatory Neural Network, Adrian Ratwatte, Samitha Somathilaka, Sasitharan Balasubramaniam, Assaf A. Gilad

School of Computing: Faculty Publications

The gene regulatory network (GRN) of biological cells governs a number of key functionalities that enable them to adapt and survive through different environmental conditions. Close observation of the GRN shows that the structure and operational principles resemble an artificial neural network (ANN), which can pave the way for the development of wet-neuromorphic computing systems. Genes are integrated into gene-perceptrons with transcription factors (TFs) as input, where the TF concentration relative to half-maximal RNA concentration and gene product copy number influences transcription and translation via weighted multiplication before undergoing a nonlinear activation function. This process yields protein concentration as the …


What Climate Change Means For Nebraska May 2024

What Climate Change Means For Nebraska

United States Environmental Protection Agency: Publications

Nebraska’s climate is changing. In the past century, most of the state has warmed by at least one degree (F). The soil is becoming drier, and rainstorms are becoming more intense. In the coming decades, flooding is likely to increase, yet summers are likely to become increasingly hot and dry, which would reduce yields of some crops, require farmers to use more water, and amplify some risks to human health.

Our climate is changing because the earth is warming. People have increased the amount of carbon dioxide in the air by 40 percent since the late 1700s. Other heat-trapping greenhouse …


Measurement Of Simplified Template Cross Sections Of The Higgs Boson Produced In Association With W Or Z Bosons In The H → B[] Decay Channel In Proton-Proton Collisions At √S =13 Tev, A. Tumasyan May 2024

Measurement Of Simplified Template Cross Sections Of The Higgs Boson Produced In Association With W Or Z Bosons In The H → B[] Decay Channel In Proton-Proton Collisions At √S =13 Tev, A. Tumasyan

Kenneth Bloom Publications

Differential cross sections are measured for the standard model Higgs boson produced in association with vector bosons (W, Z) and decaying to a pair of b quarks. Measurements are performed within the framework of the simplified template cross sections. The analysis relies on the leptonic decays of the W and Z bosons, resulting in final states with 0, 1, or 2 electrons or muons. The Higgs boson candidates are either reconstructed from pairs of resolved b-tagged jets, or from single large-radius jets containing the particles arising from two b quarks. Proton-proton collision data at √s = …


Bagging Improves The Performance Of Deep Learning-Based Semantic Segmentation With Limited Labeled Images: A Case Study Of Crop Segmentation For High-Throughput Plant Phenotyping, Yinglun Zhan, Yuzhen Zhou, Geng Bai, Yufeng Ge May 2024

Bagging Improves The Performance Of Deep Learning-Based Semantic Segmentation With Limited Labeled Images: A Case Study Of Crop Segmentation For High-Throughput Plant Phenotyping, Yinglun Zhan, Yuzhen Zhou, Geng Bai, Yufeng Ge

Department of Statistics: Faculty Publications

Advancements in imaging, computer vision, and automation have revolutionized various fields, including field-based high-throughput plant phenotyping (FHTPP). This integration allows for the rapid and accurate measurement of plant traits. Deep Convolutional Neural Networks (DCNNs) have emerged as a powerful tool in FHTPP, particularly in crop segmentation—identifying crops from the background—crucial for trait analysis. However, the effectiveness of DCNNs often hinges on the availability of large, labeled datasets, which poses a challenge due to the high cost of labeling. In this study, a deep learning with bagging approach is introduced to enhance crop segmentation using high-resolution RGB images, tested on the …


Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik May 2024

Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Impacts Of El Niño On The Florida Reef: A Case Study Of The 2016 El Niño Event, Evvie Yendra May 2024

Impacts Of El Niño On The Florida Reef: A Case Study Of The 2016 El Niño Event, Evvie Yendra

Department of Environmental Studies: Undergraduate Student Theses

Coral reefs are vital ecosystems to coastal communities and the world’s oceans. They support other organisms, protect shorelines, and benefit coastal economies through fishing and recreation. Today, coral reefs face many threats, including ocean acidification, bleaching due to increased ocean temperatures, and disease. These threats are typically heightened during El Niño events across the globe. With a focus on the Florida Reef, these data encompass three key regions (Southeastern Florida, The Florida Keys, and Dry Tortugas) over the years 2014, 2016 (an El Niño event), and 2018. As 2024 is interpreted to be an El Niño year, this study predicts …


Strongly Stated And Loosely Held: Examining Stewart Brand's Role In The Ecomodernist Project, Liam J. Baker May 2024

Strongly Stated And Loosely Held: Examining Stewart Brand's Role In The Ecomodernist Project, Liam J. Baker

Department of Environmental Studies: Undergraduate Student Theses

With the ecomodernist environmental perspective emerging in the wake of the 2015 publication of An Ecomodernist Manifesto, many researchers have sought to critique the ecomodernists and their theories of separating humanity from nature, intensifying agriculture, expanding energy production, and relying on technology to resolve the environmental challenges of the 21st century. In this paper, I add to these critiques by examining the history of Stewart Brand, one of the coauthors of An Ecomodernist Manifesto, to highlight connections between his personal environmental perspective, his material impacts, and the ecomodernist project as a whole. By analyzing the discourse produced by and about …


Building A Data Pipeline And Machine Learning Model For Insurance Data, Connor Weyers May 2024

Building A Data Pipeline And Machine Learning Model For Insurance Data, Connor Weyers

Honors Program: Senior Projects (Public)

Insurance telematics is an emerging and exciting field. It combines the advancements in GPS tracking, computational analytics, data processing, and machine learning into a useful tool to help insurance companies make the best product for their consumers. This is why National Indemnity looked to implement a telematics portion to their business processes of underwriting insurance policies and sponsored a School of Computing Senior Design project. In this report, we will first review existing solutions that been used to solve problems and subproblems similar to that we are given in this project. We then propose designs for the data pipeline and …


America's Next Top Ej Model: Assessing The Role Of Food Access In Environmental Justice Models, Allyson Barry May 2024

America's Next Top Ej Model: Assessing The Role Of Food Access In Environmental Justice Models, Allyson Barry

Department of Environmental Studies: Undergraduate Student Theses

Disruptions to weather patterns and ecosystems due to climate change are a global challenge. However, previous research has found that communities of color, traditionally underprivileged communities, and socioeconomically disadvantaged communities are disproportionately burdened with adverse health outcomes, higher propensities of exposure to weather disasters and pollution, and well-being inequalities. The field of environmental justice (EJ) seeks to eliminate such disparities through environmental laws, regulations, and policies. Published in 2022, the Centers for Disease Control and Prevention (CDC) and the Agency for Toxic Substances and Disease Registry (ATSDR) formulated the Environmental Justice Index (EJI) as a data tool to identify communities …


The Ring-Closing Reaction Of Cyclopentadiene Probed With Ultrafast X‑Ray Scattering, Lisa Huang, Lauren Bertram, Lingyu Ma, Nathan Goff, Stuart W. Crane, Asami Odate, Thomas Northey, Andrés Moreno Carrascosa, Mats Simmermacher, Sri Bhavya Muvva, Joseph D. Geiser, Matthew J. Lueckheide, Zane Phelps, Mengning Liang, Xinxin Cheng, Ruaridh Forbes, Joseph S. Robinson, Matthew J. Hayes, Felix Allum, Alice E. Green, Kenneth Lopata, Artem Rudenko, Thomas J. A. Wolf, Martin Centurion, Daniel Rolles, Michael P. Minitti, Adam Kirrander, Peter M. Weber May 2024

The Ring-Closing Reaction Of Cyclopentadiene Probed With Ultrafast X‑Ray Scattering, Lisa Huang, Lauren Bertram, Lingyu Ma, Nathan Goff, Stuart W. Crane, Asami Odate, Thomas Northey, Andrés Moreno Carrascosa, Mats Simmermacher, Sri Bhavya Muvva, Joseph D. Geiser, Matthew J. Lueckheide, Zane Phelps, Mengning Liang, Xinxin Cheng, Ruaridh Forbes, Joseph S. Robinson, Matthew J. Hayes, Felix Allum, Alice E. Green, Kenneth Lopata, Artem Rudenko, Thomas J. A. Wolf, Martin Centurion, Daniel Rolles, Michael P. Minitti, Adam Kirrander, Peter M. Weber

Martin Centurion Publications

The dynamics of cyclopentadiene (CP) following optical excitation at 243 nm was investigated by time-resolved pump−probe X-ray scattering using 16.2 keV X-rays at the Linac Coherent Light Source (LCLS). We present the first ultrafast structural evidence that the reaction leads directly to the formation of bicyclo[2.1.0]pentene (BP), a strained molecule with three- and four-membered rings. The bicyclic compound decays via a thermal backreaction to the vibrationally hot CP with a time constant of 21 ± 3 ps. A minor channel leads to ring-opened structures on a subpicosecond time scale.


Seeing Is Believing: Religious Views, Perceptions Of Pollution, And Environmental Attitudes, Katelynn (Sage) Shadoan May 2024

Seeing Is Believing: Religious Views, Perceptions Of Pollution, And Environmental Attitudes, Katelynn (Sage) Shadoan

Department of Sociology: Dissertations, Theses, and Student Research

This study explores the intersection of religious beliefs, perceptions of pollution, and environmental attitudes among Americans. Drawing upon Lynn White's seminal argument regarding Christian theology and its implications for environmental stewardship, this research investigates the role of biblical literalism in shaping environmental attitudes, particularly among conservative Christians. Using nationally representative survey data and logistic regression models, the study examines how the perceptions of pollution moderate the effects of views of the Bible on environmental concern. The findings reveal that while perceived pollution exposure is strongly associated with environmental attitudes, it does not moderate the association between biblical literalism and environmental …


Star-Based Reachability Analysis Of Binary Neural Networks On Continuous Input, Mykhailo Ivashchenko May 2024

Star-Based Reachability Analysis Of Binary Neural Networks On Continuous Input, Mykhailo Ivashchenko

School of Computing: Dissertations, Theses, and Student Research

Deep Neural Networks (DNNs) have become a popular instrument for solving various real-world problems. DNNs’ sophisticated structure allows them to learn complex representations and features. However, architecture specifics and floating-point number usage result in increased computational operations complexity. For this reason, a more lightweight type of neural networks is widely used when it comes to edge devices, such as microcomputers or microcontrollers – Binary Neural Networks (BNNs). Like other DNNs, BNNs are vulnerable to adversarial attacks; even a small perturbation to the input set may lead to an errant output. Unfortunately, only a few approaches have been proposed for verifying …


Opportunities For Urban Resilience To Climate Change: Understanding Local Climate Perceptions, Motivations, And Barriers To Green Infrastructure Use, Emmilene Berski May 2024

Opportunities For Urban Resilience To Climate Change: Understanding Local Climate Perceptions, Motivations, And Barriers To Green Infrastructure Use, Emmilene Berski

Department of Geography: Dissertations, Theses, and Student Research

Global climate change poses a substantial threat to cities in the United States, particularly through increases in flooding and extreme heat. Cities must adapt to these threats to preserve their residents’ livelihoods and prevent economic loss. One adaptation strategy is the implementation of green infrastructure (GI). The opportunity for GI to foster urban resilience to climate change necessitates a deeper understanding of the extent to which cities utilize GI as a strategy for local climate change adaptation as well as perceptions and motivations surrounding the use of GI at a local level. I sought to address this need through a …


A Little Loud And A Little Alone: A Phenomenology Of Leadership Identity Construction Among Women In Higher Education Technology, Amy Barry May 2024

A Little Loud And A Little Alone: A Phenomenology Of Leadership Identity Construction Among Women In Higher Education Technology, Amy Barry

Department of Teaching, Learning, and Teacher Education: Theses and Other Student Research

This qualitative study is an exploration of how women in higher education information technology (IT) positions navigate constructing their leadership identities. This includes the messy, personal, internal identity work that occurs prior to claiming their leadership identities on the public stage, followed by an examination of what the experience of attempting to claim and negotiate a leadership identity is like in the social context of their organizations. This educational and sociological study employs an Interpretative Phenomenological Analysis approach with a series of three interviews per participant that allowed the researcher to deeply explore the personal identity experiences of participants. Findings …


Detection Of Deficiencies And Data Analysis Of Bridge Members With Deep Convolutional Neural Networks, Bennett Jackson May 2024

Detection Of Deficiencies And Data Analysis Of Bridge Members With Deep Convolutional Neural Networks, Bennett Jackson

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

Concrete cracks and structural steel corrosion are two of the most common defects in bridges. Quantifying and classifying these defects provide bridge inspectors and engineers with valuable data for assessing deterioration levels. However, the bridge inspection process is typically a subjective, time intensive, and tedious task, as defects can be overlooked or in locations not easily accessible. Previous studies have investigated deep learning-based inspection methods, implementing popular models such as Mask R-CNN and U-Net. The architectures of these models offer certain advantages depending on the required task. This thesis aims to evaluate and compare Mask R-CNN and U-Net regarding their …


Asteroidal Sets And Dominating Targets In Graphs, Oleksiy Al-Saadi May 2024

Asteroidal Sets And Dominating Targets In Graphs, Oleksiy Al-Saadi

School of Computing: Dissertations, Theses, and Student Research

The focus of this PhD thesis is on various distance and domination properties in graphs. In particular, we prove strong results about the interactions between asteroidal sets and dominating targets. Our results add to or extend a plethora of results on these properties within the literature. We define the class of strict dominating pair graphs and show structural and algorithmic properties of this class. Notably, we prove that such graphs have diameter 3, 4, or contain an asteroidal quadruple. Then, we design an algorithm to to efficiently recognize chordal hereditary dominating pair graphs. We provide new results that describe the …


Eco-Anxiety Effects College Students, Alexa Edmundson May 2024

Eco-Anxiety Effects College Students, Alexa Edmundson

Department of Environmental Studies: Undergraduate Student Theses

A survey was conducted on the UNL student population to evaluate whether college students, 18-25 year olds who are currently attending an accredited post-secondary school, are experiencing eco-anxiety and if eco-anxiety affects their pro-environmental behaviors. Climate change is taking a toll not only physically on us but also mentally. The mental health of people, especially college students, is not often studied in relation to climate change, but if we are to understand how to create change in this issue then we need to be looking at the whole picture. The hypothesis is that if college students are experiencing eco-anxiety, then …


Eco-Anxiety Effects College Students, Alexa Edmundson May 2024

Eco-Anxiety Effects College Students, Alexa Edmundson

Department of Environmental Studies: Undergraduate Student Theses

A survey was conducted on the UNL student population to evaluate whether college students, 18-25 year olds who are currently attending an accredited post-secondary school, are experiencing eco-anxiety and if eco-anxiety affects their pro-environmental behaviors. Climate change is taking a toll not only physically on us but also mentally. The mental health of people, especially college students, is not often studied in relation to climate change, but if we are to understand how to create change in this issue then we need to be looking at the whole picture. The hypothesis is that if college students are experiencing eco-anxiety, then …


Grading Climate Action Plans In The Midwest, Megan Baker May 2024

Grading Climate Action Plans In The Midwest, Megan Baker

Department of Environmental Studies: Undergraduate Student Theses

As agreed upon by international climate scientists, decarbonization in the American Midwest is critical to keeping the planet below the 1.5C increase in global temperature from pre-industrial levels. However, most previous research that evaluates climate action plans (CAPs) to find their weaknesses and provide policy recommendations neglects this crucial region of the United States. To fill this gap, this paper replicates Deetjen et al.’s (2018) review of CAPs in 29 US cities by applying their CAP rubric to 11 Midwestern cities. The results of both quantitative analysis were used to analyze the differences in plans in the Midwest versus the …


Framing Wildlife Conservation: Exploring Political Bias In States' Wildlife Action Plans, Ciara Nelson May 2024

Framing Wildlife Conservation: Exploring Political Bias In States' Wildlife Action Plans, Ciara Nelson

Department of Environmental Studies: Undergraduate Student Theses

Climate change affects regions of the United States differently due to factors such as the country's diverse physical landscapes, political environments, and population distributions. This variation leads to varying impacts on humans, wildlife, and ecosystems, with anthropogenic climate change—acknowledging humans as a significant contributor—being a point of contention, especially among some prominent politicians. The relationship between political party affiliation and climate change acknowledgment is evident, with recent political discourse highlighting differing views on the severity of climate change. This political framing influences how environmental policies are perceived and accepted, with the choice of language and framing playing a crucial role …


Towards Sustainable Development: Civic Architecture As Material Banks, Kathleen O'Gara May 2024

Towards Sustainable Development: Civic Architecture As Material Banks, Kathleen O'Gara

Masters in Architecture Program: Theses

This thesis posed the question, “How can buildings be designed to be disassembled and reused to reduce construction and demolition waste and reduce our unsustainable reliance on raw materials?” Designing for disassembly and reuse has the potential to dramatically increase the life of building materials, thus decreasing construction and demolition waste relating to architecture. When designing with deconstruction and reuse in mind, designers must consider the next life of these materials. The thesis was further narrowed to push the adaptability of these materials by designing a structural kit of parts. The structure system is often seen as a stable and …


5-Year Strategic Direction, 2024–2028: Institute Of Agriculture And Natural Resources, University Of Nebraska–Lincoln, Institute Of Agriculture And Natural Resources University Of Nebraska-Lincoln May 2024

5-Year Strategic Direction, 2024–2028: Institute Of Agriculture And Natural Resources, University Of Nebraska–Lincoln, Institute Of Agriculture And Natural Resources University Of Nebraska-Lincoln

Institute of Agriculture and Natural Resources: Institute Publications

IANR: Integrating Learning, Discovery, and Engagement for an Even Better Nebraska

Includes an introduction, description of the components of the Institute of Agriculture and Natural Resources at the University of Nebraska–Lincoln, the IANR pillars, stratgeic aims for 2024–2028, and a section on implementation.


Public Horticulture: Process And Design Of The Lincoln Botanical Garden, Brad Kindler May 2024

Public Horticulture: Process And Design Of The Lincoln Botanical Garden, Brad Kindler

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Beginning in 2012, the local non-profit, The Lincoln Botanical Garden, began organizing the conceptual design and creation of a glass conservatory within a botanical garden in Lincoln, Nebraska. These proposed urban enhancements seek to fill a gap in garden amenities in the city by providing year-round access to public horticulture programming and education.

This project, Public Horticulture: Process and Design of the Lincoln Botanical Garden, documents these efforts and makes design recommendations for a themed Glacial Erratic Garden that could be constructed within the botanical garden.

Advisors: Ellen Paparozzi and Sam Wortman


Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu May 2024

Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The uncertainty in model projections of future precipitation across the Sahel has persisted across many generations of Earth System Models (ESMs), with some models predicting drying and others moistening across this region. These discrepancies in future projections pose a challenge for stakeholders and decision makers. Many projections of Sahel precipitation found in the ESMs participating in the sixth phase of Coupled Model Intercomparison Project (CMIP6) show a zonal dipole in precipitation trend, with moistening across the Central and Eastern Sahel and drying projected for the Western Sahel. Previous studies have connected precipitation variability across the Sahel to changes in various …


Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson May 2024

Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Left-moving (LM) supercells, though rarer than right-moving (RM) supercells, may produce significant severe weather. However, there are very few existing studies on LM supercells, particularly polarimetric radar analyses. The upgrade of the nationwide Weather Surveillance Radar-1988 Doppler (WSR-88D) network to polarimetric capability and subsequent studies vastly improved understanding of RM supercells, but similar efforts have largely not been made for LM supercells. This study employs an automated polarimetric radar signature detection algorithm to examine a dataset of significant severe (hail ≥ 2.00”, wind ≥ 65 kts) LM supercells to quantify their polarimetric signatures. Comparisons are made with RM supercells to …


A Dual-Polarimetric Analysis Of A Large Sample Of Left-Moving Supercells, Ben Schweigert May 2024

A Dual-Polarimetric Analysis Of A Large Sample Of Left-Moving Supercells, Ben Schweigert

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Supercells have been researched extensively since they were first described over 50 years ago. They are prolific severe weather producers, responsible for the most severe hail, severe wind gusts, and tornadoes. These rotating thunderstorms require attention from forecasters to protect life and property from their threats, most effectively done with Doppler radars. While extensive amounts of radar-based investigations have been completed, they focused almost exclusively on right-moving (RM) supercells, resulting in a knowledge gap surrounding their counter-rotating (left-moving, LM) partners. This study works to fill the void by developing a dataset of LM supercells and analyzing the dual-polarimetric features observed …


First-Principles Studies Of Spin Transport And Spin-Orbit Torques, Giovanni Gabriel Báez Flores May 2024

First-Principles Studies Of Spin Transport And Spin-Orbit Torques, Giovanni Gabriel Báez Flores

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation presents first-principles studies focusing on the effects of interfacial spin relaxation in metallic interfaces, interfacial intermixing on spin-orbit torques, and the effects of alloying on the transport properties of Fe|MgO|Fe magnetic tunnel junctions. Spin transport and spin-orbit torques are at the heart of phenomena in magnetic memory devices, such as tunnel magnetoresistance and magnetization switching. This work explores spin transport, spin-orbit coupling, spin-orbit torques, and tunneling magnetoresistance in a variety of materials and interfaces.

First discussed is the role of spin-orbit coupling at metallic interfaces by establishing a generalized magnetoelectronic circuit theory for normal metal (NM) interfaces, (NM|NM), …