Engineering Commons^™

Groundwater Flooding On Highways In The Nebraska Sandhills: Applying Remote Sensing, Precipitation And Groundwater Modeling To Determine Depth, Cause And Frequency, Aaron R. Mittelstet

Nebraska Department of Transportation: Research Reports

Climate change significantly impacts infrastructure sustainability, particularly through shifts in precipitation patterns, intensity, and duration. These precipitation dynamics may increase the occurrence of surface water and groundwater flooding. Groundwater in the Nebraska Sand Hills (NSH), including the thickest portions of the High Plains Aquifer, extends close to the land surface in interdunal areas, making the NSH vulnerable to groundwater flooding. Recent events involving heavy precipitation, snow melt, and rising groundwater levels have caused prolonged highway flooding, disrupting transportation networks. This study estimates groundwater flood inundation depth, duration and frequency in the highways of NSH using remote sensing techniques and groundwater …

Geophysical Tools For Agricultural Management: Trends, Challenges, And Opportunities, Sophia Becker, Trenton Franz, Yufeng Ge, Joe Luck, Derek M. Heeren

School of Natural Resources: Faculty Publications

Agrogeophysics is a convergence of proximal soil sensing and hydrogeophysics in which geophysical methods are used to describe soil patterns and dynamics that shape agronomic management (including precision agriculture). To fully realize its potential for optimizing agricultural production, current barriers and targets for future agrogeophysics research must be identified. In this review, we compare the trajectory of agrogeophysics within peer-reviewed literature, patents, and the US university extension literature and examine the current challenges and opportunities for supporting agricultural production and sustainability with agrogeophysical tools. We conducted a repeatable search of Web of Science and Scopus for seven geophysical methods (electromagnetic …

Ai Tools In Natural Resources And Environmental Systems For The Classroom, Research, Extension And Industry, Derek M. Heeren, C. T. Agouridis, Debabrata Sahoo, Isaya Kisekka, Trisha L. Moore

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This white paper synthesizes a series of panel insights on AI adoption across education, Extension, research and industry contexts within natural resources and environmental systems. It emphasizes that while advanced machine learning and generative AI introduce structural shifts in autonomy, scale, and cognitive augmentation, their value lies in augmenting, not replacing, human expertise. Applied tool examples include decision‑support systems for rural water operators, HAB‑diagnosis apps integrating image classification and natural‑language guidance, an irrigation educational chatbot tailored to user background, and sensor‑driven orchard AI for light interception estimation and data gap filling. A recurring design imperative involves co‑development with end users, …

Data-Driven Methods For Signal Analysis And Nonlinear System Identification, Cristian Felipe López Ruano

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

In recent years, data-driven modeling has gained considerable attention in nonlinear system identification, offering a powerful alternative to traditional physics-based methods. This has been possible by advances in machine learning, sparse regression, and differential equations in a weak form, which allow the accurate capture of complex nonlinear dynamics, even when the measurements are in strong background noise. Moreover, integrating these models with physical knowledge further enhances their reliability and interpretability, making them suitable for a wide range of science and engineering applications.

In this dissertation, we investigate algorithms for data-driven nonlinear system identification to obtain ordinary differential equations that govern …

Analysis Of Vision Transformers And Domain Adaptation In Long-Range Facial Recognition, Zachary Michael Swanson

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

Atmospheric turbulence presents a significant barrier to long-range facial recognition, introducing severe geometric distortions and blur that degrade image quality. This thesis investigates deep learning approaches for mitigating these effects, with a focus on transformer based architectures and domain adaptation strategies.

An in-depth benchmarking study was performed using convolutional neural networks (CNNs) and vision transformers (ViTs) on the Husker BRIAR Research Collection from up to 500m (HBRC-500) face dataset. The results demonstrated that vision transformers, particularly hierarchical vision transformers like the shifted-window (Swin) transformer, outperform CNN-based models at long distances due to their ability to model global spatial relationships and …

Biocomputing Approach To Modeling And Modulating Calcium Signaling, Sehee Sun

School of Computing: Dissertations, Theses, and Student Research

Biocomputing is an emerging field that seeks to perform computational tasks using biological substrates and processes. Unlike conventional computing systems based on silicon hardware, biocomputing leverages the parallelism, energy efficiency, and complex dynamics of living systems. Among various cellular mechanisms, calcium (Ca2+) signaling stands out as a central regulator of diverse biological functions, offering a promising basis for programmable logic and control in living cells.

This thesis introduces a novel framework for modeling and modulating Ca2+ dynamics using biologically inspired Boolean logic circuits. Specifically, we propose the Ca2+ Boolean Logic (CaBL) model, in which Ca2+ fluxes and interactions are abstracted …

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, …

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 …

Development And Implementation Of A Vector-Quantized Transformer Autoencoder For Monitoring Bicycle Road Conditions, Kewei Ren

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

Adviser: Chun-Hsing Ho

The long-term, sustainable assessment of bicycle road conditions is essential for ensuring cyclist safety and promoting equitable infrastructure management. While traditional detection methods based on manual thresholds have demonstrated some effectiveness, they carry limitations due to the diversity of pavement materials, cyclist behaviors, and sensor platforms. Although recent advances in deep learning offer promising alternatives, established techniques are primarily applied to highway anomaly detection and are rarely adapted for bicycle roads. Furthermore, most related studies lack clear definitions for anomalies and transparent annotation procedures, resulting in a shortage of effective datasets and detection methods specifically for bicycle …

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 …

Legacy Nutrient Transport By Overland Sheet Flow, John E. Gilley, Ryan P. Mcgehee, Kenneth M. Wacha

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The transport of phosphorus (P) and nitrogen (N) from sites containing varying quantities of legacy nutrients was evaluated in this investigation. The data that were examined were collected during four previously reported field hydrologic studies performed in eastern Nebraska. Additional flow was introduced to the top of the rainfall simulation plots to replicate runoff conditions occurring along a hillslope. It was observed that both P and N delivery were influenced by runoff rate on sites where beef cattle manure or inorganic fertilizer had been applied. Legacy nutrient delivery appeared to have been influenced by the quantity of nutrients released at …

Evaluation Of Waste Plastic Addition Via Dry Method On Asphalt Mixture Performance, Isabella Madeira Bueno

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

Incorporating waste plastic (WP) into hot mix asphalt (HMA) offers a promising approach to enhance recycling rates and improve asphalt concrete (AC) performance, particularly in moisture damage resistance. However, results vary widely due to differences in WP types, sizes, and mixing methods. The lack of standardized procedures, especially for the dry process, has led to inconsistent integration and unclear roles of WP in AC mixtures. Studies suggest that introducing WP to pre-heated aggregates at temperatures exceeding its melting point can enhance mixture resistance to rutting, cracking, and moisture damage. In this context, this study was conducted in two phases to …

A Discrete-Time Adaptive Sliding Mode Controller For A Multicopter With A Suspended Payload, John Helzer

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis presents a Discrete-time Adaptive Sliding Mode Controller (DASMC) for control of a multicopter with a suspended payload. DASMC is designed to stabilize the multicopter at a desired position while minimizing the load oscillations induced by a significant hanging payload. The proposed DASMC minimizes the need for system-specific parameters like tunable gains and improves robustness to both external disturbances and model uncertainties compared with existing controllers. The controller is designed for direct digital implementation on a variety of multicopter platforms with considerations like discrete-time design, adaptive gain shrinking, and saturation handling. When deployed on a real multicopter in an …

Farmnav-Uav: A Field-Ready Autonomous Uav For Tracking Static And Dynamic Trajectories In Agricultural Applications, Veera Venkata Ram Murali Krishna Rao Muvva

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

This study presents the design and development of a custom-built uncrewed aerial vehicle (UAV) tailored for precision agriculture. Unlike commercial UAVs, which are often constrained by proprietary systems and limited hardware customization, the proposed platform emphasizes modularity, upgradeability, and cost-effectiveness. The UAV is equipped with a Cube Blue flight controller for reliable low-level actuation and a Raspberry Pi 4 companion computer that executes a Model Predictive Control (MPC) algorithm for high-level trajectory optimization and stability enhancement.

Most conventional UAV autopilot systems rely on non-optimal control strategies, such as proportional–integral–derivative (PID) controllers, which can be inadequate for dynamic or resource-constrained environments. …

Integrating High Throughput Phenotyping Approaches To Characterize Plant Traits And Support Nutrient Management Research, Katie J. Bathke

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

Over the past decade, considerable research has addressed the social, economic, and agronomic challenges posed by imbalanced nutrient applications, particularly nitrogen and, more recently, sulfur. In response, high throughput plant phenotyping, as one of the latest approaches, has contributed to the development of innovative techniques for assessing key plant phenotypes under stress over time in both field and greenhouse environments. However, there is a limited number of studies applying these techniques for nutrient management, particularly in scenarios where two abiotic stressors coexist, such as the combination of water stress and nitrogen deficiency, or concurrent nitrogen and sulfur deficiencies.

In chapter …

Ecen191/Robo150 Robotics Tools: Evaluating The Impact Of Project-Based Learning On Teaching Effectiveness, Nikhil Satyala

UNL Faculty Course Portfolios

The course selected for this study aims to introduce the skills and knowledge needed to utilize software and hardware tools used to design and operate robots. In this introductory course, undergraduate students in the Robotics Engineering major are provided with the opportunity to broaden their skill set with focus on specializing in one of three engineering disciplines (Software, Electrical and Mechanical). The primary goal of this course is to teach how develop the proficiency in basic concepts in robotics and enable the students to build and program a small-scale fully functional robotic arm. In this portfolio study, I investigated the …

Nebraska Balanced Mix Design - Phase Ii, Farzad Yazdipanah, Mahdieh Khedmati, Jamilla Teixeira, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

This study aimed to propose a performance-based framework to evaluate highly recycled asphalt mixtures containing polymer-modified binders for potential use in a balanced mix design (BMD) specification in the state of Nebraska. For that, loose and compacted mixtures were directly collected from plant and field projects within a benchmarking study, subjected to an extensive experimental program. The laboratory investigation employed different monotonic tests recommended in BMD Phase 1, as well as the dynamic modulus test. Three long-term aging protocols were investigated in terms of their impact on the mechanical, rheological, and chemical characteristics of asphalt mixtures and binders. Moreover, field …

Automated Client Dashboard For Facts Student Information System, Kashish Syed

Honors Program: Senior Projects (Public)

This project addresses the challenges of student data migration for K-12 educational institutions to the FACTS Student Information System (SIS). Historically, data migration from legacy platforms has been a manual and error-prone process. To streamline this workflow, an interactive client dashboard and automated validation system were developed as part of this capstone. The resulting solution is a scalable, intuitive tool that enhances data accuracy, reduces manual labor, and improves the user experience for both school administrators and FACTS staff. This report blends the technical implementation with reflections on project management, team collaboration, and lessons learned, offering a comprehensive view of …

Proposed Civil Design Package For Lincoln Youth Sports Complex, Gracie Kerr, Hayden Wulf, Kiley Pham, Caitlin Keathley

Honors Program: Senior Projects (Public)

The following report is a proposal of civil work and an engineering design package for the City of Lincoln to construct a Youth Sports Complex on the vacant lot at 2100 North 1^st Street, Lincoln, Lancaster County, Nebraska. The city has requested five U10 to U14 combination baseball and softball fields, one championship softball field, and one championship baseball field. Additionally, a playground area, concessions building, and designated parking areas have been requested. This design package includes introductory company and project information, a summary of the design request and constraints, three overall design alternatives, discipline-specific engineering designs and recommendations, …

Benefits And Applications Of Learning With Virtual Reality, Michael W. Timm

Honors Program: Senior Projects (Public)

Education is a fundamental pillar of society. It equips students for employment and interpersonal relations. Virtual reality (VR) has emerged as a transformative technology in the field of education. The aim of this paper is to synthesize existing research in order to determine the benefits of utilizing virtual reality in a variety of education settings, such as K-12 classrooms, universities, and workplace training. This paper observes significant benefits of virtual reality in constructivist and experiential learning, gamified learning, and tailored practice. This analysis also finds that virtual reality is advantageous for educational accessibility, particularly for absentee students and impoverished students. …

Hickory Street Square Revitalization, Spencer Knight, Grace Dungan, Tim Kula, Evan Lauritsen, Lindsey Mennenga

Honors Program: Senior Projects (Public)

The Hickory Street Square Revitalization Project seeks to transform a central public space in Sidney, Nebraska into a dynamic, community-oriented area that supports local events, economic activity, and cultural heritage. The project addresses six core objectives: 1) convertible street design, 2) parking lot reconfiguration, 3) public amenities, 4) event flexibility, 5) lighting and signage, and 6) old electric plant renovation. A conceptual design was developed by the design team (S.T.E.E.L. Sentinel Solutions) by synthesizing the most effective features of three preliminary alternatives, shaped further through community feedback and evolving project constraints. The final project design minimizes disruption to existing activity …

Stop Design: Rethinking The Approach To Public Transit's Architecture, Elizabeth M. Nielsen

Architecture Masters of Science Program: Theses

Public spaces are the foundation of our social health and wellbeing, but are often designed without considering the needs of the public, creating spaces that people do not feel encouraged to use. Just as public space design as a whole often falls short of serving the public, the same can be said for a subset of public space design, public transit stops. While they are public spaces created for the purpose of waiting, their design rarely reflects this.

Well-designed public transit stops are capable of both maintaining existing ridership and drawing in new riders. Most commonly, this design occurs at …

From In-The-Head To In-The-World: Frameworks For Understanding And Applying Computational Thinking, Justin Olmanson, Gretchen K. Larsen, Azadeh Hassani

Department of Teaching, Learning, and Teacher Education: Faculty Publications

In the five decades since Papert coined the term Computational Thinking (CT), it has become a core framework for thinking about learning, problem-solving, design, and creativity. Although CT is most commonly, and initially, associated with the cognitive orientations involved in coding and learning to code, it also includes situated and critical processes related to computational problem solving. Herein we unpack ways researchers in different fields and points in time have organized CT. We include creative coding as a uniquely generative lens for rethinking CT, outlining its potential as an expressive, constructionist, and culturally situated practice. In doing so, we explore …

Drainage Area Limitations Of Single Watershed, Peak Flow Estimates From Nrcs Methods, Timothy A. Maughan, Rollin H. Hotchkiss, Riley Hales

Nebraska Department of Transportation: Research Reports

Most state Department of Transportation roadway design sections predict peak flow for culvert design using, amongst other approaches, Natural Resources Conservation Service (NRCS) TR-20 technology. Even though this technology is more than 50 years old, there are no clear guidelines for how large a single watershed drainage area may be while remaining appropriate for predicting peak discharge with this method. Our objective was to identify the drainage area where TR-20 peak flow predictions significantly deviate from flow frequency predictions. We developed flow frequency estimates for 130 small-area stream gage sites in rural Nebraska and compared the calculated return period discharges …

Conversion Of Thermal Energy Stored In Conductive Concrete To Electricity With Thermoelectric Generators, Moustafa M. Al Adawi

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

This paper presents a proof-of-concept experimental study on the use of conductive concrete as thermal energy storage and its conversion into electricity. The conductive concrete is heated to 100°C by supplying electricity, and the stored thermal energy is converted back into electricity using thermoelectric generators (TEGs). Measurement results demonstrate that the conductive concrete effectively stores thermal energy up to 100°C, and this energy can be successfully converted into electricity. The findings highlight the potential of conductive concrete as a reliable medium for thermal energy storage.

Advisor: Lim Nguyen

A Machine Learning Framework For Packet Anomaly Detection In Smartgrid Substation Networks, Sowmya Bandari

School of Computing: Dissertations, Theses, and Student Research

The increasing reliance on Smart Grid Substation Networks for efficient electricity distribution has amplified cybersecurity vulnerabilities, particularly within Supervisory Control and Data Acquisition (SCADA) systems. The IEC 60870-5-104 (IEC-104) protocol, widely adopted for communication between Remote Terminal Units (RTUs) and Human-Machine Interfaces (HMIs), lacks inherent encryption and authentication mechanisms, rendering it susceptible to sophisticated cyberattacks. Threats such as False Data Injection Attacks (FDIAs), command injection, covert attacks and replay attacks pose significant risks by manipulating grid control signals, potentially leading to undetected operational disruptions, cascading failures, or system-wide instability. Conventional signature-based Intrusion Detection Systems (IDS) often fail to identify zero-day …

Physics Embedded Neural Network: A Novel Data-Free Numerical Method For Solving Computational Physics Problems, Pawan Gaire

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

A novel approach for solving partial differential equations (PDEs) using neural networks for scientific computing is introduced. The proposed approach, referred to as physics-embedded neural network (PENN), features a unique architecture that incorporates the PDE and boundary conditions information directly within the final fully-connected layer of the feed-forward neural network (NN). The key aspect of PENN is the parallel numerical embedding of a differential equation associated with physical problems within the activation function of the network’s final layer. This integration leads to a new class of computational solvers competitive with classical methods like the Finite Element Method (FEM) and capable …

Carbon Fiber Cv Tripod Axle Design: Husker Motorsports Formula Sae, Taylor D. Boudreaux

Honors Program: Senior Projects (Public)

The 2024–2025 HMS Formula SAE senior design team successfully reduced axle system weight, cost, and improved manufacturability using a bonded tripod joint and ±45° intermediate modulus carbon fiber tube. The final design was validated on HMS 25, with no failures under rigorous testing.

Budget:
/="/"> Total project cost was $1,165.64, exceeding the initial $1,000 target due to unanticipated test rig expenses. However, per-axle production cost was reduced from $525.31 to $383.37 through in-house manufacturing, use of on-hand epoxy (DP460), and switching to cost-effective 7068 aluminum. The axle-specific cost was $766.74.

Timeline:
/="/"> Despite early delays from building a torsional testing …

A Case Study On Readiness Of Engineers In Agricultural Technology Start-Ups, Katie Marie Mowat

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

This dissertation explores the perceptions of practicing engineers regarding the skills necessary to be workforce-ready at agricultural technology (ag-tech) start-ups in the Midwestern United States. A qualitative case study methodology is leveraged, combining both interview and job description data. Given their uniqueness, the study divides the ag-tech start-up industry into two subcases: livestock and cropping systems. The Work Readiness Integrated Competence Model (WRICM) is used as the theoretical framework for this study and informs the conceptual framework and analysis processes. The study identified skills that fit into thirteen distinct categories, which are further grouped into four overarching resource groups. Skills …

Optimizing Nitrogen Management: Assessing Nitrate Transport In The Deep Vadose Zone And Its Impact On Groundwater Quality In East-Central Nebraska, Muili O. Lawal

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

Groundwater contamination by nitrate (NO₃-N) is a growing environmental and public health concern driven largely by intensive agricultural fertilizer applications. The vadose zone plays an important role in NO₃-N transport, influencing groundwater quality and agricultural sustainability. This study investigated NO₃-N leaching dynamics in the deep vadose zone of Water Quality Sub-Area 30 (WQA30) within the Lower Loup Natural Resources District (LLNRD), northeast of Columbus, Nebraska (mean groundwater NO₃-N: 20.3 mg/L), using soil cores from 16 shallow (to 6.1 m) and four deep (down to 25.9 m) across four zones, two with inorganic fertilizer (Zones 1 and 4) and two with …