Physical Sciences and Mathematics Commons^™

Electron Scattering From 1-Methyl-5-Nitroimidazole: Cross-Sections Formodeling Electron Transport Through Potential Radiosensitizers, Ana I. Lozano, Lidia Álvarez, Adrián García-Abenza, Carlos Guerra, Fábris Kossoski, Jaime Rosado, Francisco Blanco, Juan Carlos Oller, Mahmudul Hasan, Martin Centurion, Thorsten Weber, Daniel S. Slaughter, Deepthy M. Mootheril, Alexander Dorn, Sarvesh Sarvesh, Paulo Limão-Vieira, Rafael Colmenares, Gustavo García

Department of Physics and Astronomy: Faculty Publications

In this study, we present a complete set of electron scattering cross-sections from 1-Methyl-5- Nitroimidazole (1M5NI) molecules for impact energies ranging from 0.1 to 1000 eV. This information is relevant to evaluate the potential role of 1M5NI as a molecular radiosensitizers. The total electron scattering cross-sections (TCS) that we previously measured with a magnetically confined electron transmission apparatus were considered as the reference values for the present analysis. Elastic scattering cross-sections were calculated by means of two different schemes: The Schwinger multichannel (SMC) method for the lower energies (below 15 eV) and the independent atom model-based screening-corrected additivity rule with …

Light Alters Leaf Breakdown Rates And Metabolic Activity In Anthropogenically Impacted Nebraska Streams, William Reilly Farrell

School of Natural Resources: Dissertations, Theses, and Student Research

Algal growth influences carbon breakdown rates in aquatic ecosystems; however, the magnitude and direction of these effects differ based on ecosystem context. To explore algal priming effects on decomposition in anthropogenically impacted ecosystems, I conducted light manipulation experiments in three streams, each surrounded by different land uses (i.e., predominantly urban, row crop, or concentrated animal feeding operation) across Nebraska. I measured leaf breakdown rates, metabolic activity, fungal and algal biomass, and leaf percent carbon (C) and phosphorus (P) to assess the effect of light differences. These streams were impacted by sedimentation and turbidity over the course of the leaf incubation. …

Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska’s pronghorn population has been stable over the last decade, yet their presence on the landscape remains a contentious subject amongst private landowners. Conversion of grassland for crop production and increased anthropogenic activity has drastically altered pronghorn behavior throughout their current range, however basic ecology and resource use by pronghorn in Nebraska remains poorly understood. Establishing baseline population metrics and seasonal patterns of resource use for this population at the eastern periphery of the species range is critical to guide management actions. We deployed GPS collars on 110 adult pronghorn to quantify survival, mortality risk, and seasonal resource selection in …

Critical Factors And Individual Decision Making In Earthquake And Tsunami Preparedness Among Coastal Communities Inoregon U.S.A., Shelley Olds

School of Natural Resources: Dissertations, Theses, and Student Research

Earthquakes and tsunamis are natural hazards that cause considerable loss of life, destruction of property and infrastructure, and economic damage. Preparedness is critical in regions of significant earthquake and tsunami risk. A key challenge for organizations that manage hazard preparedness and response is mobilizing earthquake preparedness among individuals and families. This dissertation provides an examination of individual earthquake and tsunami preparedness from both a global and regional perspective. It comprises two publications that explore various aspects of disaster preparedness.

Chapter One provides an overview of global seismic and tsunami hazards, along with potential impacts, and addresses the challenges in promoting …

Crustal Structures Of Diebold Knoll And Adjacent Juan De Fuca Oceanic Crust From Integration Of Seismic, Gravity And Magnetic Data, Md Ariful Islam

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

Cascadia Subduction Zone (CSZ) has a long history of devastating earthquakes as the Juan de Fuca plate subducts beneath North America, where an imminent megathrust earthquake is expected. Compared to other subduction zones, CSZ exhibits unusually low seismic activity, particularly in the central region with respect to relatively high seismicity zones to the north and south. Some researchers attribute this behavior to subducted seamounts, although their impact on seismicity remains poorly understood and highly debated in the literature. Examining subducted seamounts is challenging due to complexity of the overburden strata. That is why this study focuses on an isolated not-yet-subducted …

Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid

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

Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …

Analysis Of Syndrome-Based Iterative Decoder Failure Of Qldpc Codes, Kirsten D. Morris, Tefjol Pllaha, Christine A. Kelley

Department of Mathematics: Faculty Publications

Iterative decoder failures of quantum low density parity check (QLDPC) codes are attributed to substructures in the code’s graph, known as trapping sets, as well as degenerate errors that can arise in quantum codes. Failure inducing sets are subsets of codeword coordinates that, when initially in error, lead to decoding failure in a trapping set. In this paper we examine the failure inducing sets of QLDPC codes under syndrome-based iterative decoding, and their connection to absorbing sets in classical LDPC codes.

Search For Nonresonant Pair Production Of Highly Energetic Higgs Bosons Decaying To Bottom Quarks, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

A search for nonresonant Higgs boson (H) pair production via gluon and vector boson (V) fusion is performed in the four-bottom-quark final state, using proton-proton collision data at 13 TeV corresponding to 138 fb⁻¹ collected by the CMS experiment at the LHC. The analysis targets Lorentz-boosted H pairs identified using a graph neural network. It constrains the strengths relative to the standard model of the H self-coupling and the quartic VVHH couplings, κ_2V, excluding κ_2V = 0 for the first time, with a significance of 6.3 standard deviations when other H couplings …

Waterbody Size Predicts Bank- And Boat-Angler Efforts, Derek S. Kane, Kevin L. Pope, Keith D. Koupal, Mark A. Pegg, Christopher J. Chizinski, Mark A. Kaemingk

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Bank- and boat-angler efforts are logistically difficult and costly to estimate, preventing landscape-scale estimates that are required to address current and future challenges (e.g., climate change, invasive species) for inland recreational fisheries. Using a large Nebraska, USA, recreational fishery dataset (N = 67 waterbodies), we demonstrate that waterbody size can be used to predict bank- and boat-angler efforts across a heterogeneous landscape of extra small (< 104 ha) and large (> 647 ha) waterbodies. Bank and boat anglers respond to waterbody size, however these relationships appear to be unique between the two angler types. Boat-angler efforts increased as a function of waterbody size, whereas bank-angler …

Two-Particle Azimuthal Correlations In Γp Interactions Using Ppb Collisions At √SNn=8.16tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

The first measurements of the Fourier coefficients (V_nΔ) of the azimuthal distributions of charged hadrons emitted from photon-proton (γp) interactions are presented. The data are extracted from 68.8nb⁻¹of ultra-peripheral proton-lead (pPb) collisions at √s_NN=8.16 TeVusing the CMS detector. The high energy lead ions produce a flux of photons that can interact with the oncoming proton. This γp system provides a set of unique initial conditions with multiplicity lower than in photon-lead collisions but comparable to recent electron-positron and electron-proton data. The V_nΔ coefficients are presented in ranges of event multiplicity and transverse momentum …

Computation Of The Basic Reproduction Numbers For Reaction-Diffusion Epidemic Models, Chayu Yang, Jin Wang

Department of Mathematics: Faculty Publications

We consider a class of k-dimensional reaction-diusion epidemic models (k = 1; 2; • • • ) that are developed from autonomous ODE systems. We present a computational approach for the calculation and analysis of their basic reproduction numbers. Particularly, we apply matrix theory to study the relationship between the basic reproduction numbers of the PDE models and those of their underlying ODE models. We show that the basic reproduction numbers are the same for these PDE models and their associated ODE models in several important scenarios. We additionally provide two numerical examples to verify our analytical results.

Search For Medium Effects Using Jets From Bottom Quarks In Pbpb Collisions At √SNn=5.02tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

The first study of the shapes of jets arising from bottom (b) quarks in heavy ion collisions is presented. Jet shapes are studied using charged hadron constituents as a function of their radial distance from the jet axis. Lead-lead (PbPb) collision data at a nucleon-nucleon center-of-mass energy of √s_NN=5.02TeVwere recorded by the CMS detector at the LHC, with an integrated luminosity of 1.69nb⁻¹. Compared to proton-proton collisions, aredistribution of the energy inbjets to larger distances from the jet axis is observed in PbPb collisions. This medium-induced redistribution is found to be substantially larger forbjets than for …

Search For New Heavy Resonances Decaying To Ww, Wz, Zz, Wh, Or Zh Boson Pairs In The All-Jets Final State In Proton-Proton Collisions At √S=13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

A search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZHboson pairs in the all-jets final state is presented. The analysis is based on proton-proton collision data recorded by the CMS detector in 2016–2018 at a centre-of-mass energy of 13TeVat the CERN LHC, corresponding to an integrated luminosity of 138fb⁻¹. The search is sensitive to resonances with masses between 1.3and 6 TeV, decaying to bosons that are highly Lorentz-boosted such that each of the bosons forms a single large-radius jet. Machine learning techniques are employed to identify such jets. No significant excess over the estimated …

Search For Narrow Resonances In The B-Tagged Dijet Mass Spectrum In Proton-Proton Collisions At √S=13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

A search is performed for narrow resonances decaying to final states of two jets, with at least one jet originating from a b quark, in proton-proton collisions at √s = 13 TeV. The data set corresponds to an integrated luminosity of 138 fb⁻¹ collected with theCMS detector at the LHC. Jets originating from energetic b hadrons are identified through a b-tagging algorithm that utilizes a deep neural network or the presence of a muon inside a jet. The invariant mass spectrum of jet pairs is well described by a smooth parametrization and no evidence for the production of …

A Thermodynamics-Based Versatile Evapotranspiration Estimation Method Of Minimum Data Requirement For Water Resources Investigations, Jozsef Szilagyi, Richard D. Crago

School of Natural Resources: Faculty Publications

A recent, two-parameter version of the thermodynamically derived complementary relationship (CR) of evaporation has been tested on a monthly basis at 124 FLUXNET stations around the globe. Local, station-by-station calibration explained 91% (R2) of the variance in eddy-covariance (EC) obtained latent-heat fluxes with the same Nash-Sutcliffe efficiency (NSE) value. When the dimensionless Priestley-Taylor parameter (α) was expressed as a universal function (f) of the estimated wet-environment air temperature (Tw), station-by-station calibration of the single dimensionless parameter, b (accounting for moisture advection), yielded an R² value of 87% and NSE of 86%. Global calibration (all stations …

Temperature-Pressure Phase Diagram Of Confined Monolayer Water/Ice At First-Principles Accuracy With A Machine-Learning Force Field, Bo Lin, Jian Jiang, Xiao Cheng Zeng, Lei Li

Chemistry Department: Faculty Publications

Understanding the phase behaviour of nanoconfined water films is of fundamental importance in broad fields of science and engineering. However, the phase behaviour of the thinnest water film – monolayer water – is still incompletely known. Here, we developed a machine-learning force field (MLFF) at first-principles accuracy to determine the phase diagram of monolayer water/ice in nanoconfinement with hydrophobic walls. We observed the spontaneous formation of two previously unreported high-density ices, namely, zigzag quasi-bilayer ice (ZZ-qBI) and branched-zigzag quasi-bilayer ice (bZZ-qBI). Unlike conventional bilayer ices, few inter-layer hydrogen bonds were observed in both quasi-bilayer ices. Notably, the bZZ-qBI entails a …

Pull-Push Method: A New Approach To Edge-Isoperimetric Problems, Sergei L. Bezrukov, Nikola Kuzmanovski, Jounglag Lim

Department of Mathematics: Faculty Publications

We prove a generalization of the Ahlswede-Cai local-global principle. A new technique to handle edge-isoperimetric problems is introduced which we call the pull-push method. Our main result includes all previously published results in this area as special cases with the only exception of the edge-isoperimetric problem for grids. With this we partially answer a question of Harper on local-global principles. We also describe a strategy for further generalization of our results so that the case of grids would be covered, which would completely settle Harper’s question.

Holocene Rice Rats (Genus Oryzomys) From The Upper Mississippi River Drainage Basin, Hugh H. Genoways

Zea E-Books Collection

The expansion and collapse of the geographic range of the Texas rice rat (Oryzomys texensis) in the upper Mississippi River drainage basin at the end of the Holocene was a unique event in North American mammals. In a period of about 4000 years with a point of origin near the American Bottom in Illinois, these small rodents extended their geographic range in a straight-line distance of over 950 km to the west into Nebraska and the same distance to the east into Pennsylvania. Then in less than 400 years this range expansion collapsed back to a point where …

Probing Heavy Majorana Neutrinos And The Weinberg Operator Through Vector Boson Fusion Processes In Proton-Proton Collisions At √S = 13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

The first search exploiting the vector boson fusion process to probe heavy Majorana neutrinos and the Weinberg operator at the LHC is presented. The search is performed in the same-sign dimuon final state using a proton-proton collision dataset recorded at √s = 13 TeV, collected with the CMS detector and corresponding to a total integrated luminosity of 138 fb⁻¹. The results are found to agree with the predictions of the standard model. For heavy Majorana neutrinos, constraints on the squared mixing element between the muon and the heavy neutrino are derived in the heavy neutrino mass range 50 …

When Are The Natural Embeddings Of Classical Invariant Rings Pure?, Melvin Hochster, Jack Jeffries, Vaibhav Pandey, Anurag K. Singh

Department of Mathematics: Faculty Publications

Consider a reductive linear algebraic group G acting linearly on a polynomial ring S over an infinite field; key examples are the general linear group, the symplectic group, the orthogonal group, and the special linear group, with the classical representations as inWeyl’s book: For the general linear group, consider a direct sum of copies of the standard representation and copies of the dual; in the other cases, take copies of the standard representation. The invariant rings in the respective cases are determinantal rings, rings defined by Pfaffians of alternating matrices, symmetric determinantal rings and the Plücker coordinate rings of Grassmannians; …

Adsorptive–Photocatalytic Performance For Antibiotic And Personal Care Product Using Cu0.5Mn0.5Fe2O4, Chanat Chokejaroenrat, Chainarong Sakulthaew, Athaphon Angkaew, Apiladda Pattanateeradetch, Wuttinun Raksajit, Kanokwan Teingtham, Piyaporn Phansak, Pawee Klongvessa, Daniel D. Snow, Clifford E. Harris, Steven Comfort

Nebraska Water Center: Faculty Publications

The amount of antibiotics and personal care products entering local sewage systems and ultimately natural waters is increasing and raising concerns about long-term human health effects. We developed an adsorptive photocatalyst, Cu_0.5Mn_0.5Fe₂O₄ nanoparticles, utilizing co-precipitation and calcination with melamine, and quantified its efficacy in removing paraben and oxytetracycline (OTC). During melamine calcination, Cu_0.5Mn_0.5Fe₂O₄ recrystallized, improving material crystallinity and purity for the adsorptive–photocatalytic reaction. Kinetic experiments showed that all four parabens and OTC were removed within 120 and 45 min. We found that contaminant adsorption and reaction …

Water Current, Volume 55, No. 2, Summer 2023

Water Current Newsletter

No abstract provided.

Mentoring Experiences Of Undergraduate Students And Faculty Members In Science, Technology, Engineering, And Mathematics, Pamela Martínez Oquendo

School of Natural Resources: Dissertations, Theses, and Student Research

I present a comprehensive view of mentoring experiences of undergraduate students and faculty members in science, technology, engineering, and mathematics (STEM). In CHAPTER 1, I describe a brief outline of this dissertation. In CHAPTER 2, I present an interpretative phenomenological analysis of the lived experiences of former STEM undergraduate mentors of the Nebraska STEM For You (NE STEM 4U) afterschool mentoring program. In CHAPTER 3, I describe how the ramifications of faculty mentorship influence the science pipeline using a qualitative synthesis. In CHAPTER 4, I describe how the STEM faculty-student mentoring engagement involves a strong psychological support component using a …

Spatial & Temporal Agnostic Deep-Learning Based Radio Fingerprinting, Fahmida Afrin

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

Radio fingerprinting is a technique that validates wireless devices based on their unique radio frequency (RF) signals. This method is highly feasible because RF signals carry distinct hardware variations introduced during manufacturing. The security and trustworthiness of current and future wireless networks heavily rely on radio fingerprinting. In addition to identifying individual devices, it can also differentiate mission-critical targets. Despite significant efforts in the literature, existing radio fingerprinting methods require improved robustness, scalability, and resilience. This study focuses on the challenges of spatial-temporal variations in the wireless environment. Many prior approaches overlook the complex numerical structure of the in-phase and …

Economic Value Of User Interface Design, Anna Kruse

Honors Theses

The economic value of well-designed user interfaces (UI) and user experiences (UX) is challenging to quantify, a topic that the current literature does not sufficiently explore. Those responsible for deciding whether to invest resources in UI/UX typically base these decisions on monetary considerations. The link between effective UI/UX design and profit may not be immediately clear to most, yet it is universally acknowledged that satisfied customers lead to successful business. To underscore the importance of investing in UI/UX, it is crucial to define the relationship between effective design and economic success in a way that can be understood by designers, …

Applications Of Financial Mathematics: An Analysis Of Consumer Financial Decision Making, Alyssa Betterton

Honors Theses

Students always ask, “How can this be applied to the real world?” Mortgages, car loans, and credit card bills are things that almost everyone will have to make decisions about at some point in their lives. This research discusses the many different financial choices that consumers have to make. Consumers can use this information to understand how interest rates, the length of the loan, and the initial amount being borrowed affects the amount that is paid back to the companies. The intent of this thesis is to present the mathematical theory of interest. A web-based application has been built based …

Convergence And Transdisciplinary Teaching In Quantitative Biology, Robert Mayes, Joseph Dauer, David Owens

School of Natural Resources: Faculty Publications

The United States National Science and Technology Council has made a call for improving STEM (Science, Technology, Engineering, and Mathematics) education at the convergence of science, technology, engineering, and mathematics. The National Science Foundation (NSF) views convergence as the merging of ideas, approaches, and technologies from widely diverse fields of knowledge to stimulate innovation and discovery. Teaching convergency requires moving to the transdisciplinary level of integration where there is deep integration of skills, disciplines, and knowledge to solve a challenging real-world problem. Here we present a summary on convergence and transdisciplinary teaching. We then provide examples of convergence and transdisciplinary …

Mass Spectrometry Of The White Adipose Metabolome In A Hibernating Mammal Reveals Seasonal Changes In Alternate Fuels And Carnitine Derivatives, Frazer I. Heinis, Sophie Alvarez, Matthew T. Andrews

School of Natural Resources: Faculty Publications

Mammalian hibernators undergo substantial changes in metabolic function throughout the seasonal hibernation cycle. We report here the polar metabolomic profile of white adipose tissue isolated from active and hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus). Polar compounds in white adipose tissue were extracted from five groups representing different timepoints throughout the seasonal activity-torpor cycle and analyzed using hydrophilic interaction liquid chromatography-mass spectrometry in both the positive and negative ion modes. A total of 224 compounds out of 660 features detected after curation were annotated. Unsupervised clustering using principal component analysis revealed discrete clusters representing the different seasonal timepoints throughout …

Incorporation Of Carbon Dioxide Production And Transport Module Into A Soil-Plant-Atmosphere Continuum Model, Sahila Beegum, Wenguang Sun, Dennis Timlin, Zhuangji Wang, David Fleisher, Vangimalla R. Reddy, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Carbon dioxide release from agricultural soils is influenced by multiple factors, including soil (soil properties, soil-microbial respiration, water content, temperature, soil diffusivity), plant (carbon assimilation, rhizosphere respiration), atmosphere (climate, atmospheric carbon dioxide), etc. Accurate estimation of the carbon dioxide (CO₂) fluxes in the soil and soil respiration (CO₂ flux between soil and atmosphere) requires a process-based modeling approach that accounts for the influence of all these factors. In this study, a module for CO₂ production via root and microbial respiration and diffusion-based carbon dioxide transport is developed and integrated with MAIZSIM (a process-based maize crop growth …

Wildlife Ecological Risk Assessment In The 21st Century: Promising Technologies To Assess Toxicological Effects, Barnett A. Rattner, Thomas G. Bean, Val R. Beasley, Philippe Berny, Karen M. Eisenreich, John E. Elliott, Margaret L. Eng, Phyllis C. Fuchsman, Mason D. King, Rafael Mateo, Carolyn B. Meyer, Jason M. O'Brien, Christopher J. Salice

United States Geological Survey: Staff Publications

Despite advances in toxicity testing and the development of new approach methodologies (NAMs) for hazard assessment, the ecological risk assessment (ERA) framework for terrestrial wildlife (i.e., air‐breathing amphibians, reptiles, birds, and mammals) has remained unchanged for decades. While survival, growth, and reproductive endpoints derived from whole-animal toxicity tests are central to hazard assessment, nonstandard measures of biological effects at multiple levels of biological organization (e.g., molecular, cellular, tissue, organ, organism, population, community, ecosystem) have the potential to enhance the relevance of prospective and retrospective wildlife ERAs. Other factors (e.g., indirect effects of contaminants on food supplies and infectious disease processes) …