Physical Sciences and Mathematics Commons^™

Winds Of Change: Charting A Pathway To Ecosystem Monitoring Using Airborne Environmental Dna, Rachel L. Tulloch, Clare I.M. Adams, Matthew A. Barnes, Elizabeth L. Clare, Henrik C. Van De Ven, Andrew Cridge, Francisco Encinas-Viso, Kristen Fernandes, Dianne M. Gleeson, Erin Hill, Anna J.M. Hopkins, Anna M. Kearns, Gracie C. Kroos, Anna J. Macdonald, Francesco Martoni, Angela Mcgaughran, Todd G.B. Mclay, Linda E. Neaves, Paul Nevill, Andrew Pugh, Kye J. Robinson, Fabian Roger, Tracey V. Steinrucken, Mieke Van Der Heyde, Cecilia Villacorta-Rath, Jenny Vivian

Research outputs 2022 to 2026

Airborne environmental DNA (airborne eDNA) analysis leverages the globally ubiquitous medium of air to deliver broad species distribution data and support ecosystem monitoring across diverse environments. As this emerging technology matures, addressing critical challenges and seizing key opportunities will be essential to fully realize its potentially transformative impact. In June 2024, the Southern eDNA Society convened over 100 researchers, industry leaders, and biodiversity management stakeholders in a landmark workshop to evaluate the current state of airborne eDNA research and chart a course for future development. Participants explored opportunities for integrating airborne eDNA into existing monitoring systems, but they unanimously agreed …

Garage Sale Web-Based Information System, Sonachi Mogbogu

Systems Manuals - 2026

The Garage Sale web application is in response to a business need of an online interactive system. This system will support the interaction between owners and shoppers of garage sale event. The online information system is a great idea to implement because it will help create sales awareness which will lead to increase in the customer base, and increased sales for event organizers. People are used to the traditional approaches, advertising events through word-of-mouth and posting signs alongside roads, however, having an online information system will be more effective in reaching a wider market of buyers. The traditional approaches do …

Rattler Python, Samer Jabor

Systems Manuals - 2026

The Rattler Python project is an interactive game-based learning system that intends to teach the basic concepts of Python programming through guided instruction, gameplay challenges, and review-based assessments. The document contains a proposal for this system consisting of problem definition, background research, existing solutions, and the proposed product, together with the system scope, assumptions, and the organization of the remainder of this document.

Evaluating The Influence Of Carbon Quantum Dots On Starch-Based Bioplastics: Toward Potential Food Packaging Applications, Shima Jafarzadeh, Mitra Golgoli, Zeinab Qazanfarzadeh, Mehrdad Forough, Peng Wu, Wendy Timms, Colin J. Barrow, Minoo Naebe, Masoumeh Zargar

Research outputs 2022 to 2026

Developing biodegradable food packaging films is crucial for reducing dependence on petroleum-based plastics. In this study, nitrogen-doped carbon quantum dots (CDs) were synthesized from citric acid and ethylenediamine via hydrothermal treatment and incorporated into sago starch films at concentrations of 0.5 %, 1 %, 3 %, and 4 % w/w of total solids using a solution casting method. The effects of CDs on structural, thermal, antioxidant, optical, and physicochemical properties were systematically investigated. CD addition enhanced the UV-shielding ability of the films. At 4 % CD content, UV transmittance decreased by 56.4 % (UVA), 66.7 % (UVB), and 73.9 % …

Real-World Continuous Smartwatch-Based User Authentication, N. Al-Naffakh, N. Clarke, F. Li, P. Haskell-Dowland

Research outputs 2022 to 2026

User authentication is often regarded as the "gatekeeper"of cyber security. It has, however, long suffered from significant usability issues that have resulted in research focussing upon frictionless and transparent biometric approaches. Activity-based user authentication - a technique that authenticates a user by what they are physically doing at a specific point in time has attracted significant attention, particularly due to the increasing popularity of smartwatches. This research aims to overcome limitations in prior work by exploring the viability of the approach in real-world conditions. The study presents two principal experiments, one focused upon a constrained environment to provide a control …

The Response And Recovery Of Carbon And Water Fluxes In Australian Ecosystems Exposed To Severe Drought, C. Stephens, B. Medlyn, L. Williams, J. Knauer, A. Inbar, E. Pendall, S. K. Arndt, J. Beringer, C. M. Ewenz, N. Hinko-Najera, L. B. Hutley, P. Isaac, M. Liddell, W. Meyer, C. E. Moore, J. Cranko Page, R. Silberstein, W. Woodgate

Research outputs 2022 to 2026

Climate change-driven increases in drought risk pose a critical threat to global carbon and water cycles. However, ecosystem-scale responses remain poorly quantified, particularly for severe, multiyear drought events. We addressed this gap by examining ecosystem-scale carbon and water flux sensitivity to the extreme 2018–19 drought in Australia using data from 14 eddy covariance flux sites. The ecosystems span grasslands and semi-arid woodlands to tropical and temperate forests. The driest sites (classed as “grass” and “very dry”) experienced drastic productivity impacts, with a 65% decrease in Gross Primary Productivity (GPP) over 2 years relative to the pre-drought average. However, fluxes in …

Red Forest, Lucas Shilts

Senior Project

Sustaining large numbers of astronauts on Mars will require greenhouses capable of supplementing astronaut dietary needs. Lower solar irradiation and high levels of ionizing radiation on the Martian surface complicate the growth of crops on the red planet. Crops on Mars must be protected from radiation sources while still receiving sufficient illumination to grow. This research seeks to develop a Martian greenhouse illumination and heating design capable of efficiently providing plants the illumination and warmth needed while protecting them from the Martian radiation environment. This research explores a design for a direct-light subsurface Martian greenhouse which employs sun-tracking mirrors, vertical …

Learn, Sleep, Remember, Repeat, Charlie Martinez, Christian Fink

Physics Student Scholarship

My research focused on using computational methods to study the effect of sleep on memory. There are many simplifications that we used to break down this hefty question, but two are essential to understand: (1) we modeled a simple network (connection diagram included in poster) that comprised of only about 800 neurons (for reference the human brain contains about 80 billion neurons) and represented the connection between two brain regions the thalamus and the cortex, and (2) we modeled memory as a simple learning rule that strengthened connections between neurons that fired in sequence and weakened connections that pointed in …

Understanding Stellar Element Formation Through Nuclear Reactions, Irena Langer, Mally Panek, Kiyah Young-Wilson, Adam Fritsch

Physics Student Scholarship

Studying nuclear structure has many applications, such as developing a stronger understanding of stellar nucleosynthesis, or how elements are formed inside of stars. Our research focuses on analysis of the proton evaporation nuclear reaction of Carbon-12 on Aluminum-27 in order to extract information about the structure of the nuclei involved. We are studying the cross section, or likelihood, of this reaction, using both experimental and modeled data. Since the cross section of a nuclear reaction depends on the physical characteristics of the nuclei involved, we can use the cross section to analyze our work.

Measuring How Much Judges Matter For Case Outcomes, Ryan W. Copus, Ryan Hübert

Faculty Works

A large empirical literature examines how judges’ traits affect how cases get resolved. This literature has led many to conclude that judges matter for case outcomes. But how much do they matter? Existing empirical findings understate the true extent of judicial influence over case outcomes since standard estimation techniques hide some disagreement among judges. We devise a machine learning method to reveal additional sources of disagreement. Applying this method to the Ninth Circuit, we estimate that at least 38% of cases could be decided differently based solely on the panel they were assigned to.

Sensor Lag Adjustments On A Mobile Meteorological Cart In Tropical Environments: A Case Study From An Urban Park In Singapore, Moshe Eliezer Mandelmilch, Sin Kang Yik, Beatrice H. Ho, Graces N. Y. Ching, Peter J. Crank, Winston T. L. Chow

Research Collection College of Integrative Studies

This study adds to the growing literature on mobile platforms by examining the performance of the Singapore MaRTy (SMaRTy) in conducting mobile micrometeorological measurements along a designated route in an urban park in Singapore, reflecting a pedestrian walking experience. The main objective of the study was to calculate the sensor lag for the mobile climate measurements: Air Temperature (TA), and Relative Humidity (RH) of SMaRTy along a designated route in an urban park in Singapore based on data from fixed stations (HOBO sensors) in two significant synoptic meteorological periods during the Northeast and Southwest monsoons. Statistically significant regression models were …

In Situ Thrust Measurement Of Fish During Locomotion; Test Case: Sharks, Braedon Payne, Bryan A. Keller, Daniel Weihs, Roi Gurka

Physics and Engineering Science

We present a novel method of measuring thrust of aquatic animals using in situ video data of swimming motions. To demonstrate its utility, the method was applied to several large elasmobranch species, which are typically highly challenging to measure. Using motion tracking software, we analyzed video footage of wild and captive sharks to track their instantaneous position and speed. In order to estimate the force output, we used the tail/body motion based on the swimming modes of the fish to calculate the water displaced by this motion during locomotion. Using Newton 3rd law, we have calculated the instantaneous force exerted …

Statistical Power To Detect Simultaneous Violation Of Proportionality In Hazards And Additive Assumption In Cox Regression Model, Lawrence Mensah Agbota

Theses and Dissertations

The Cox proportional hazards regression model is a widely employed semi-parametric tool in epidemiological and medical research for analyzing time-to-event data and assessing the relationship between patient survival times and one or more predictors. This method involves regression analyses necessitating a meticulous approach to careful examination of the covariates and the relationship among covariates included in the model through a series of critical decisions and steps. Violation of the additivity of the effects and the proportionality in hazards (PH) assumption can lead to biased results and misleading scientific findings. We conducted a Monte Carlo simulation study to assess the performance …

Empowering Weight Loss: A Pragmatic Randomized Controlled Trial Of A Theory-Driven Self-Regulation Mobile App For Young Adults With Excess Body Weight, H. S. J. Chew, J. W. Ngooi, R. C. Du, P. Z. Chan, M. Jansson, B. Zhu, Y. Cao, Chong-Wah Ngo, R. Foo, A. Shabbir, D. Ho, N. Sevdalis, K. Y. Ngiam

Research Collection School Of Computing and Information Systems

Background/Introduction: Obesity is projected to affect more than half of the global population by 2035, posing significant health and economic challenges. While lifestyle modification is considered a cornerstone of weight management, its effectiveness often relies on substantial support systems. Purpose: This study aimed to evaluate the effectiveness of a 12-week, standalone Temporal Self-Regulation Theory (TST)-based weight loss mobile application, which integrates self-regulation techniques, food logging, and dietary nudging, in promoting weight loss among young adults with excess body weight. Methods: A two-arm, parallel-group, 1:1 randomized controlled trial was conducted, adhering to the CONSORT-Outcomes 2022 Extension guidelines. Participants completed a face-to-face …

Ts-Diff: Two-Stage Diffusion Model For Low-Light Raw Image Enhancement, Yi Li, Zhiyuan Zhang, Jiangnan Xia, Jianghan Cheng, Qilong Wu, Junwei Li

Research Collection School Of Computing and Information Systems

This paper presents a novel Two-Stage Diffusion Model (TS-Diff) for enhancing extremely low-light RAW images. In the pre-training stage, TS-Diff synthesizes noisy images by constructing multiple virtual cameras based on a noise space. Camera Feature Integration (CFI) modules are then designed to enable the model to learn generalizable features across diverse virtual cameras. During the aligning stage, CFIs are averaged to create a target-specific CFIT, which is fine-tuned using a small amount of real RAW data to adapt to the noise characteristics of specific cameras. A structural reparameterization technique further simplifies CFIT for efficient deployment. To address color shifts during …

Rustmap: Towards Project-Scale C-To-Rust Migration Via Program Analysis And Llm, Xuemeng Cai, Jiakun Liu, Xiping Huang, Yijun Yu, Haitao Wu, Chunmiao Li, Bo Wang, Imam Nur Bani Yusuf, Lingxiao Jiang

Research Collection School Of Computing and Information Systems

Migrating existing C programs into Rust is increasingly desired, as Rust offers superior memory safety while maintaining C’s high performance. Existing automated translation tools, such as C2Rust, may rely too much on syntactic, template-based translation and generate unsafe Rust code that is hard for human developers to read, maintain, or even compile. More semantic-aware translation that produces safer, idiomatic, and runnable Rust code is much needed. This paper introduces a novel dependency-guided and large language model (LLM)-based C-to-Rust translation approach, RustMap, based on three key ideas: (1) Utilize LLM’s capabilities to produce idiomatic Rust code from given small pieces of …

Dual-Target Disjointed Cross-Domain Recommendation Mediated Via Latent User Preferences, Dinh Hieu Do, Hady Wirawan Lauw

Research Collection School Of Computing and Information Systems

Users often navigate multiple platforms online, each characterized by its own set of scarce data. Recommender systems face a significant challenge in such fragmented environments. This paper proposes a novel approach to enhance recommendation systems by leveraging connections across distinct yet conceptually similar datasets from multiple platforms. We introduce a unique scenario of dual-target overlapping-free cross-platform recommendation, presenting a bridging mechanism to mutually improve across platforms and learn latent user preferences. Our approach addresses the data sparsity prevalent in each platform and enhances recommendation quality by harnessing redundant, rich, and similar domain data. Experiments validate the effectiveness of our method, …

Unbounded Multi-Hop Proxy Re-Encryption With Hra Security: An Lwe-Based Optimization, Xiaohan Wan, Yang Wang, Haiyang Xue, Mingqiang Wang

Research Collection School Of Computing and Information Systems

Proxy re-encryption (PRE) schemes enable a semi-honest proxy to transform a ciphertext of one user i to another user j while preserving the privacy of the underlying message. Multi-hop PRE schemes allow a legal ciphertext to undergo multiple transformations, but for lattice-based multi-hop PREs, the number of transformations is typically bounded due to the increase of error terms. Recently, Zhao et al. (ESORICS 2024) introduced a lattice-based unbounded multi-hop (homomorphic) PRE scheme that supports an unbounded number of hops. Nevertheless, their scheme only achieves the selective CPA security. In contrast, Fuchsbauer et al. (PKC 2019) proposed a generic framework for …

Energetic And Economic Aspects Of Rebound, Part Ii: Applications Of The Framework, Matthew Kuperus Heun, Gregor Semieniuk, Paul Brockway

University Faculty Publications and Creative Works

Widespread implementation of energy efficiency is a key greenhouse gas emissions mitigation measure, but rebound can ‘‘take back’’ energy savings. However, the absence of solid analytical foundations hinders empirical determination of rebound magnitudes. In Part I, we developed foundations of a rigorous, analytical, consumer-sided rebound framework that is approachable for both energy analysts and economists. In this paper (Part II), we develop energy, expenditure, and consumption planes, a novel, mutually consistent, and numerically precise way to visualize and illustrate rebound. Further, we operationalize the macro factor (k) for macroeconomic rebound. Using the framework and rebound planes, we calculate and show …

Response Of Soybean To Variable Irrigation Levels In Eastern Nebraska Using The Aquacrop Model, Anmol Singh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

AquaCrop was calibrated and validated for soybean [Glycine max (L.) Merr.] using 19 irrigation treatments from five years using data from field experiments. The model accurately simulated canopy cover (CC), soil water content (SWC), and grain yield, with overall validation nRMSE values of 12%, 7%, and 7%, respectively. The overall validation nRMSE for SWC in individual 30-cm soil layers was comparatively higher, at 19%. The model was subsequently applied for long-term simulations (2010–2024) to estimate soybean yield and water requirements for two dominant soil types, Yutan silty clay loam and Tomek silt loam under three irrigation levels - rainfed, …

Exploring And Characterizing Organic Chemistry Students’ Meaningful Engagement In Science Practices, John Zhou

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

Undergraduate organic chemistry frequently engages students in key science practices such as analyzing and interpreting spectroscopic data and constructing explanations through reaction mechanisms. However, these activities are often framed as procedural tasks rather than as tools for constructing knowledge. As a result, students may develop incomplete understanding of these practices, making it harder for them to see how scientific knowledge is generated and to use them meaningfully as tools for sensemaking. To better understand how students take up these practices as epistemic tools, three qualitative studies were conducted in this dissertation to investigate how undergraduate organic chemistry students reason with …

Exogenous Ketones Reduce Inflammation And Pathology In The Tgf344-Ad Rat Model, Amaya Rogers, Pheven Yohannes, Juan P. Carcamo, Preetham Gundlapally, Amaya Coker, Macy A. Seijo, Caesar M. Hernandez

Expo Student Presentations

2025 Summer Expo Poster Presentation

• Biological & Life Sciences
• Engineering
• Physical & Applied Sciences

Investigating The Thixotropy Of Fresh Struvite Cement-Based Composite: Insights On Mechanisms Of The Pastes’ Thixotropic Behavior, Ugochukwu Ewuzie, Abdulkareem O. Yusuf, Damilola Daramola, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Struvite (ST) recovered during wastewater treatment has been sparsely applied in cement-based composites. This study systematically evaluated the thixotropic behavior of cement-struvite (CST) pastes, a mix of 5–20 % ST by mass of cement, and proposed the interaction mechanisms leading to the pastes' thixotropy. The hysteresis loop area was used to establish the pastes' thixotropy and investigate its relationship with increased ST content, temperature, and yield stress. In the thixotropic behavior model used, the equilibrium shear stress was employed to examine the CST pastes' irreversible change; the characteristic time of deflocculation was used to study the flocs destruction process; and …

A Uas-Centered Investigation Of Vorticity Characteristics And Cold Pool Structure Across Forward And Left-Flank Boundaries In Supercells, Mark R. De Bruin

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

Supercell internal boundaries are the locus of tornadogenesis; thus, understanding the characteristics of these boundaries, particularly in terms of vorticity, is important for identifying the role they play in tornado formation. Insight into the overall characteristics of internal boundaries and their possible role in tornadogenesis have been driven by studies reliant on numerical modeling-based experiments. Observational studies often neglect above-surface conditions or, when these observations are made, lack the spatial resolution to resolve boundary characteristics. During TORUS (Targeted Observation by Radars and UAS of Supercells) 2019 and TORUS-LItE (TORUS Left-flank Intensive Experiment) 2023, uncrewed aircraft systems (UAS) and mobile mesonets …

Feasibility Of Using Recycled Waste Plastic In Concrete Pavements In Nebraska, Amasi Hajahja

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Waste plastic (WP) is a growing environmental concern due to its non-biodegradable nature, large-scale production, and harmful impact on natural resources. With nearly 75% of WP in the United States ending up in landfills, effective recycling strategies are urgently needed. In parallel, the limited availability of natural aggregates highlights the need for alternative materials in concrete construction. This study investigates the feasibility of using recycled waste plastic (RWP) in concrete mixtures, both as aggregates and fibers for rigid pavement applications in Nebraska. Concrete mixtures were prepared by partially replacing natural fine aggregates with recycled plastic aggregates (RPA) at replacement levels …

Use Of High-Throughput Phenomics With And Without Fungicide As A Wheat Breeding Tool, Gerardo Ivan Rivera Collazo

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

Wheat (Triticum aestivum) is an important food staple for many countries around the world and current consumption and production data demonstrate a production deficit. Breeders are challenged to help close this gap in production by selecting better cultivars with improved yields. Several methods aim to accelerate the breeding process to reduce the time required for releasing an elite variety. One of the main breeding bottlenecks is the lack of fast and reliable phenotypic data acquisition that could dissect physiological and morphological plant data. High-throughput remote sensing could have the potential to reduce this bottleneck by streamlining data acquisition, …

A Study Of Ice And Fire: Environmental Change Impacts On Lakes Of The Nebraska Sandhills, Daniel Gschwentner

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

The Nebraska Sandhills contain thousands of shallow, groundwater-fed lakes. These lakes are extremely sensitive to environmental and climatic changes due to their isolated hydrological setting and small volume. Building on previous work on the hydrology, geochemistry and long-term climate response of Sandhill lakes, my research considers how ecosystem processes such as primary production, nutrient limitation and water quality respond to short-term environmental and climatic change. In my first data chapter, I highlight that Sandhill lakes are nitrogen (N) but not phosphorus (P) limited and that N:P ratios are poor predictors of nutrient limitation status in Sandhill lakes. In my second …

A Modular Paradigm For The Directly Efficient Representation Of Kinetic Laser-Driven Plasmas, Roland D. Hesse

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

A natural inefficiency in conventional treatment of the plasma distribution arises from indiscriminate consideration of the contributions to field structure that are dynamically sourced from kinetic activity in disparate sectors of phase space. We introduce a range of techniques for model design to maximize representation efficiency without breaking key physical invariants indicative of physical reliability. An overview of varied adaptation to stable time-advance methods is given. Low-dimensional representation of a laser-driven plasma requires some creativity in differential structural modification, while direct efficiency is uncovered through the compression and rarefaction of a nonuniform momentum grid. These numerical models introduce embedded gains …

Catching A Fever: A Comparison Of Vachellia Xanthophloea Populations In The Limpopo And Luvuvhu River Floodplains Of The Makuleke Contractual Park, Kianie B. David

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

This study investigates patterns of stand structure regeneration, growth characteristics, and coarse woody debris (CWD) patterns in Vachellia xanthophloea (fever tree) stands within the Makuleke Contractual Park (MCP), a semi-arid savanna system in northern Kruger National Park (KNP), South Africa. Fieldwork was conducted across two stand types: a monospecific fever tree stand in Rietbok Vlei and a mixed-species stand in the Western Nhlangaluwe Floodplain where fever tree is established with Faidherbia albida (ana tree). Data were collected from 20 total 1/4-acre (1,011 m²) circular plots between both stands in 2024 and 2025, including seedling root collar diameter (RCD), …

Bioenergy Crop Production: Implications For Grassland Bird Communities In Southwestern Nebraska, Grace E. Schuster

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

Biofuel and bioenergy systems are components of most climate stabilization pathways to reduce greenhouse gas emissions and limit global warming. Currently, corn (Zea mays) is the predominant feedstock used for bioenergy production in the United States. However, widespread production of this monoculture crop has resulted in many negative environmental impacts. The most notorious impact has been the loss of grassland habitat due to agriculture expansion which has had detrimental effects on wildlife that depend on grassland habitat. One such group, grassland birds, has faced steeper, more consistent, and more widespread declines than any other avian guild. Therefore, strategies …