Digital Commons Network^™

Quantitative Study Of The Predictive Correlational Relationship Between Passenger Knowledge, Attitudes, And Behaviors In Aviation Ground Safety Events, Nikkolas Howard Kraay

Doctoral Dissertations and Projects

This study examined the relationships between passenger cabin safety knowledge, attitude, and behavior using the Knowledge-Attitude-Behavior (KAB) framework as the guiding theoretical model. Although prior aviation safety research has demonstrated a linear progression from knowledge to attitudes to behaviors, these studies were conducted primarily in Asian cultural contexts. The present study investigated whether this linear sequence would hold within a larger cultural passenger population. A predictive correlational design was used, and data was collected through an online survey completed by 194 adult airline passengers. The instrument measured cabin safety knowledge, attitudes, and behavioral intent, along with demographic characteristics.

Data was …

A Low-Noise And High-Gain Integrated Photoplethysmography Sensor For Continuous Vital Signs Monitoring, Neethu Mohan

Thesis/ Dissertation Defenses

Photoplethysmography (PPG) sensing is an important technology used for measuring health parameters like, heart rate, respiratory rate, blood oxygen saturation, and blood pressure (BP). The PPG sensing is used for individuals who have to periodically monitor their health due to chronic health conditions. The basic requirements of a wearable PPG sensor include non-invasiveness, prolonged battery life, and being user-friendly. These type of sensors have great demand in the healthcare applications and there is a significant rise in the demand of these sensors. The basic objective of these PPG sensors is to make the continuous vital health monitoring easier without the …

Anchorage And Bond Behavior Of Smoothsurfaced Nitinol-Sma Rebars, Mostafa Basha

Thesis/ Dissertation Defenses

The anchorage and bond behavior of smooth-surfaced Shape Memory Alloys (SMAs) is investigated in this thesis, but specifically, the focus will be on Nitinol (Ni-Ti). Nitinol has distinctive properties, including Superelasticity Effect (SE) and Shape Memory Effects (SME). These properties make Nitinol bars suitable for civil and seismic engineering applications that require resilience and durability. However, Nitinol rebars possess a smooth surface, making it difficult to achieve adequate bonding and anchorage, potentially altering their load-carrying abilities. This inadequate anchorage and bonding restrict their use in the field of structural and seismic engineering. The main aim of this study is to …

Project Management Practices In Manufacturing: An Analytical Case Study, Margaret Randle, Robert Reynolds

Honors Capstones

Global industries are undergoing significant transitions in organizational models, technological innovation, and non-economic indicators of product quality, including sustainability and operational efficiency. The current workforce needs to not only develop competency of these technical skills, but also an adaptive, system-oriented approach to problem-solving as well. This case study, which highlights a manufacturing company’s project of increasing production efficiency, presents concepts learned through the textbook Project Management: Achieving Competitive Advantage by Jeffrey K. Pinto. The study thoroughly breaks down the full project lifecycle and the integration of systems of people, data, and initiatives in a framework that can be used to …

Electrospun Pan-Derived Carbon Nanofibers Embedded With Nicofew-Based High-Entropy Oxides For Electrocatalytic Oxygen Evolution Reaction, Alireza Noroozi, Mahdavi, M. Baris Yagci, Mohammad Mahdi A. Shirazi, Saeed Bazgir, Hadi Jahangiri, Uğur Ünal

Research outputs 2022 to 2026

High-entropy oxides composed of Ni, Co, Fe, W, and a fifth transition element (Mo, Mn, or Cu) were integrated into electrospun polyacrylonitrile nanofibers to form porous nitrogen-doped carbon membranes for the oxygen evolution reaction. Gas-assisted electrospinning enabled uniform dispersion of high-entropy oxide nanoparticles within the polyacrylonitrile matrix, while calcination at 800°C produced conductive carbon frameworks embedding crystalline high-entropy oxides with homogeneous elemental distribution. Structural and surface analyses confirmed the preservation of high-entropy oxide phases, catalytic graphitization of the carbon matrix, and strong interfacial bonding between metal oxides and carbon. Among all compositions, Mo-HEO@NC exhibited the lowest overpotential (≈240 mV at …

Dynamic Cushioning Performance And Sustainability Implications Of Recycled-Content Expanded Polyethylene Foams, Jay Singh, Pratish Patel, Emily Recinos, Paulina Goncharov

Industrial Technology and Packaging

The transition toward circular materials in protective packaging requires empirical evidence that recycled-content foams can satisfy stringent shock-attenuation requirements. This study evaluates the dynamic cushioning performance of expanded polyethylene (EPE) foams formulated with 0%, 30% and 40% recycled content under controlled impact conditions following ASTM D1596. A total of 1100 drop tests were conducted across combinations of density, thickness, static load and drop height representative of distribution hazards in parcel and freight supply chains. Peak transmitted acceleration (G) was measured as the primary performance response variable.

Across the configurations evaluated, recycled-content EPE foams exhibited cushioning performance comparable to virgin materials. …

Wavetable Modification In Frequency Domain: Fourier Analysis With Matlab Implementation, Caleb Kortens

Senior Honors Theses

One of the challenges in creating computer generated music is producing life-like sounds. Music produced through computer synthesis can often sound thin and synthetic rather than vibrant and energetic. Wavetable synthesis is a method of waveform generation that uses a wavetable, which is a set of single period waves, or frames, that have varying characteristics. This method allows a synthesizer to transition between waveforms to produce a sound with time varying tone and harmonic characteristics. This adds life and movement to computer generated sounds. Wavetable synthesis is often used to imitate actual instruments, but unique wavetables can be created that …

Key Issues For Speed Safety Cameras: Results From A Semi-Structured Interview Of Agencies In The United States, Sophia Semensky, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Speed safety cameras (SSCs) are a recognized countermeasure for targeting speeding-related crashes, injuries, and fatalities. SSCs have been introduced in various cities and are steadily expanding in use both in the U.S. and internationally. The extensive literature review of domestic and international documents and research papers reveals that the U.S. has been comparatively slow to adopt SSCs, with some other countries implementing these systems more extensively and earlier. Many local agencies are eager to learn SSC best practices and implementation lessons within the U.S. context. In this research, key issues related to SSC implementation are explored through semi-structured interviews with …

Quantifying Evapotranspiration From The Wetlands In The Peripheral Area Between The Most Downstream Stream Gages And The Open Water Body Of The Great Salt Lake, Motasem S. Abualqumboz, David G. Tarboton

Publications

Study region: The eastern peripheral area between the most downstream stream gages and the open water body of the Great Salt Lake (GSL), located in northern Utah within the semiarid western United States (US). 

Study focus: As GSL levels decline, the eastern peripheral area is expanding, exposing former lakebed, much of which has transitioned into natural and managed wetlands. Evapotranspiration (ET) from these wetlands consumes water that would otherwise reach the open-water lake body, yet these losses remain poorly quantified and directly affect the GSL water balance. This study compares a water-balance-based ET estimate for the wetlands in the peripheral …

Influence Of Web Thickness And Concrete Cover On The Fire Resistance Of Aashto Type Iv Prestressed Concrete Bridge Girders, Fnu Nidhi

Electronic Theses and Dissertations 2020 - Present

Bridge fires caused by vehicle accidents, fuel tanker explosions and storage of combustible material beneath highway structures have led to severe structural damage and catastrophic collapse of prestressed concrete bridges. Critical structural collapse due to fire incidents such as I-85 prestressed concrete bridge girder collapse in Atlanta, 2017 and I-95 steel plate girder bridge partial collapse in Philadelphia, 2023 demonstrated the vulnerability of girders when exposed to extreme hydrocarbon fire temperatures exceeding 1000°C within few minutes. These events highlight the urgent need to better understand the thermal and structural behavior of bridge girders and explore design modifications that can enhance …

On Time-Series Analysis By Structured Matrix Decompositions With Applications To Signal Direction-Of-Arrival Estimation, Georgios Ierotheos Orfanidis

Electronic Theses and Dissertations 2020 - Present

Modern autonomous systems operating in highly dynamic, non-stationary environments require reliable inference from short, potentially corrupted time-series measurements, where conventional statistical methods relying on large-sample support and stationarity assumptions become fundamentally inapplicable. This dissertation develops a unified, model-free theoretical framework for time-series analysis, with a particular application to signal Direction-of-Arrival (DoA) estimation, grounded in structured matrix decompositions under both the L2-norm and L1-norm formulations.

We first approach the problem from a conventional viewpoint by carrying out standard matrix analysis directly on Hankel-structured representations of time-series data. In this context, we demonstrate that L1-norm decompositions of Hankel matrices offer strong resistance …

Water-Driven Solid Electrolyte Interphase Governs Continuous-Flow Ammonia Electrosynthesis, Peng-Bo Liu, Sheng-Liang Zhai, Ji Huang, Zhong-Shuo Zhang, Jie Zeng, Shao-Feng Li

Journal of Electrochemistry

Flow-cell architectures have emerged as a powerful platform for continuous and stable lithium-mediated nitrogen reduction (Li-NRR), enabling ambient-condition electrochemical ammonia synthesis and offering a promising alternative to Haber-Bosch processes. However, Li-NRR is exceptionally sensitive to trace water, and even minor variations in water content can profoundly alter interfacial chemistry. Here, we systematically investigate how initial water concentration affects Li-NRR performance in a continuous-flow cell. Excess water drives the formation of a thick solid electrolyte interphase (SEI) layer, which may impede nitrogen access to metallic lithium and hinder lithium-ion transport. As a result, the ammonia Faradaic efficiency collapses from ~61% to …

Insertion Of Noble Metal Free Cathodic Catalyst Layer With Fe-N-C Catalyst For Boosted Performance Of Pemfc, Shi Zhou, Muhammad Tariq, Asif Nadeem Tabish, Muhammad Salman, Fan-Di Ning, Muhammad Rayyan Tayyab, Ran-Ran Peng, Meng-Geng Hao, Wen-Mu Li, Xiao-Chun Zhou

Journal of Electrochemistry

Economical Fe-N-C catalysts are considered as promising alternatives to platinum group metal catalysts for proton exchange membrane fuel cells (PEMFCs). Despite exhibiting robust activity on rotating disk electrodes, their performance within membrane electrode assemblies often experiences limitations, such as decreased O₂ diffusion, high H₂O₂ formation, low proton conduction, and a lower electron transfer number. In this study, key factors, including proton transport, electron conduction, and gas diffusion within air-breathing PEMFCs, have been investigated by adjusting cathode catalyst layer (CCL) compositions. From the experimental results, the optimal peak power density was obtained when the loading of Fe-N-C …

Computer Vision And Deep Learning-Based Decision Support System Using Eye Motion Tracking For Nystagmus Detection, Kowshik Balasubramanian

Electronic Theses and Dissertations 2020 - Present

This thesis presents the design, implementation, and experimental validation of an artificial intelligence (AI)-driven system for detecting and quantifying nystagmus an involuntary, rhythmic oscillation of the eyes intended as a portable, low-cost complement to conventional Videonystagmography (VNG). The complete pipeline integrates six algorithmic stages: face landmark detection, contrast enhancement, background-aware pixel thresholding, grid-based vertical column filtering, connected-component cluster analysis, and centroid computation, operating in real time on standard smartphone video to extract a sub-pixel normalized iris position time-series without any specialized eye-tracking hardware or infrared illumination. The system supports diagnostic decision-making, highlighting its promise for incorporation into telemedicine settings. The …

Molecular Catalysts For Electrochemical Nitrogen Activation Toward Sustainable Ammonia Synthesis, Jin-Xiu Han, Hao Xue, Xian-Biao Fu

Journal of Electrochemistry

Homogeneous electrocatalytic nitrogen reduction reaction (NRR) provides a powerful framework to interrogate molecular nitrogen-fixation pathways under mild conditions. By tuning the metal center, ligand architecture, and reaction medium, these systems enable capturing key intermediates and delivering mechanistic insight at the molecular-level resolution. Nevertheless, advances remain constrained by highly reduced operating potentials, intense competition from the hydrogen evolution reaction (HER), limited durability in turnover, and inadequate long-term stability.

In this review, we take electron delivery to the molecular active site as the guiding principle for organizing homogeneous electrochemical N₂ activation and transformation. We classify reported systems into direct electron transfer …

A Comparative Study Of Tin Electrorefining In Molten Licl–Kcl–Cacl₂: Experimental Two-Electrode Current Control And Theoretical Three-Electrode Potential Control, Bryant Johnson, George Ankrah, Ander Fuller, Devin Rappleye

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

Molten salt electrorefining is a mature technology for metal recovery, yet conventional current‑controlled, two‑electrode operation provides limited electrochemical selectivity and restricted insight into electrode‑specific behavior. In this work, a simplified model is developed to compare current‑controlled two‑electrode electrorefining data with a potential‑controlled three‑electrode electrorefining simulation using tin in molten LiCl–KCl–CaCl₂ as a surrogate for plutonium processing. The model examines anodic and cathodic limitations under fixed‑potential operation and evaluates implications for selectivity, efficiency, and runtime relative to experimentally demonstrated two‑electrode performance. Results indicate that independent potential control enables operation closer to thermodynamic selectivity limits, with the potential to suppress impurity oxidation …

Evaluation Of Quantification Methods Applied To Overlapping Ftir Features, Benjamin P. Diehl

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

Quantifying overlapping FTIR spectral features is critical for electrochemical analysis but often requires complex deconvolution. This work systematically evaluates several area ratio and proxy-based quantification methods using a controlled synthetic spectral model with varying signal-to-noise ratio, peak spacing, width, background, and data resolution. Constrained peak fitting and fixed-window integration consistently exhibit near-perfect monotonicity (Spearman ≈ 1.000) and linearity (Pearson ≈ 0.999–1.000) across all conditions. In contrast, derivative and moment-based metrics show sensitivity to peak overlap, width, and background. These results demonstrate that physically grounded area-based methods provide the most robust and reliable quantification of overlapping FTIR features.

Critical Arteries: Prioritizing Economic Vitality And Emergency Access In Local Networks, Jeremy Hunter

Local Transportation Asset Management Conference

Standard Asset Management Plans (AMPs) often rely heavily on Pavement Condition Index, Paser ratings, and Bridge Condition Ratings to dictate repair schedules. However, a strictly condition-based approach may neglect the economic and safety criticality of specific routes. This presentation proposes a multi-variable evaluation framework for counties, cities, and towns. I will explore methods for overlaying industrial data—specifically for heavy-haul sectors like logging, masonry, and agriculture—to identify and fortify the "economic lifelines" that sustain local revenue. Furthermore, I will address the necessity of resiliency planning within the AMP. By integrating hydraulic data and flood-prone area mapping, agencies can ensure that routes …

Open Multi-Agent Systems: The Free-Range-Zoo Framework And Moasei Competition, Ceferino J. Patino Iv

School of Computing: Dissertations, Theses, and Student Research

The field of multi-agent reinforcement learning (MARL) has made significant strides in addressing sequential decision-making problems under uncertainty. However, traditional MARL frameworks assume closed-world settings with fixed agent sets, static task distributions, and unchanging environment dynamics. This thesis presents two complementary contributions that advance the state of open-world multi-agent systems research: (1) the free-range-zoo framework, an open-source environment suite for MARL in open environments featuring dynamic agent populations, evolving task sets, and changing operational frames; and (2) the MOASEI Competition, an international benchmarking event that leverages free-range-zoo to evaluate how artificial agents handle openness in complex, partially observable domains. The …

External Force Control Of Transitional And Turbulent Flows, Cesar Alberto Leos

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

Turbulence in wall-bounded flows governs momentum transport, drag, and energy efficiency in a wide range of engineering systems, yet its response to external forcing remains incompletely understood across transitional and high Reynolds number regimes. This dissertation investigates an active flow control strategy based on spanwise external forcing and demonstrates how it modifies the dynamics of transitional and turbulent channel flows with the objective of identifying the mechanisms through which forcing alters transition, flow physics, and turbulent drag reduction.

Firstly, direct numerical simulations are performed to examine the subcritical transition under external forcing. The onset and sustenance of turbulence are shown …

Integrated Approaches For Valorization Of Chicken Feather Waste: From Extraction To Application Of Keratin-Based Bioproducts, Muhammad Ehtasham Akram

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

This dissertation explores the optimization of chicken feathers keratin hydrolysate (CFKH) production using alkaline hydrolysis (AH) and sub-critical water hydrolysis (SCWH), focusing on acquiring high keratin yield in the hydrolysate. Then, CFKH along with other locally sourced materials, was used to develop bioplastics with regenerative agriculture properties (BioWRAP), with the ultimate objective of applying it as a soil mulch to suppress weeds in agricultural crops. This work also addresses challenges in process design and industrial scale-up of BioWRAP. Chapter 1 is a literature review that introduces terms like biobased, biodegradable, and bioplastics, materials and methods used to make bioplastics, and …

Ai-Driven Detection Of Failure Modes In Thermoplastic Composites Using Acoustic Emission Techniques, M. M. Shahzamanian, Li Ai, Paul Ziehl

Civil Engineering Faculty Publications

Composite materials in aircraft structures can suffer impact damage that leaves barely visible yet structurally significant defects, which degrade mechanical performance, especially under compressive loads. Existing methods for identifying failure modes in compression after impact (CAI) tests using acoustic emission (AE) data are limited in accuracy and scope. This study introduces an approach combining AE sensing with a heterogeneous ensemble convolutional neural network (CNN) to detect and classify failure mechanisms in impacted composite specimens. The novelty of this work lies in employing Red, Green, and Blue (RGB) wavelet images, produced through continuous wavelet transform (CWT) of AE signals, as inputs …

Water Velocity And Discharge From Tidal Freshwater Creeks In Forested And Herbaceous Wetlands, Austin S. Hudson, G. Curtis Roegner, Gary E. Johnson, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Acoustic Doppler Current Profilers were deployed in four tidal creeks within forested swamps and herbaceous marshes in the lower Columbia River. Measurements were collected over 12 to 20-day periods during high and low river stage, and then analyzed using wavelet tidal analysis software (CWT_Multi) to characterize temporal variability of water elevation, velocity, and discharge. While subject to similar fluvial and tidal forcing, nuances in creek geometry led to large differences in their hydraulic response. Most obviously, creeks in the higher elevation forested swamps were hydraulically isolated, which limited subtidal discharge but increased tidal monthly variability of discharge in comparison to …

Modified Anodic Stripping Voltammetry For In Situ Analysis Of Liquid Metal Composition In Molten Salt Electrorefining Systems, James H. Manner

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The development of in-situ analytical techniques for high-temperature molten salt systems is critical for advancing electrorefining in nuclear fuel recycling and metallurgical purification. This study proposes Modified Anodic Stripping Voltammetry (MASV), using a “dip-and-strip” approach where a tungsten electrode captures molten Sn–Ni alloy before stripping in LiCl–KCl–CaCl₂ at 415 °C. OCP results showed rapid loss of the metal layer due to poor wetting, and stripping peaks gave compositions inconsistent with the alloy, likely reflecting Sn/Sn²⁺ and Sn²⁺/Sn⁴⁺ redox processes. These results highlight interfacial limitations and the need for improved electrode materials and surface modification.

A Machine Learning Framework For Ddos Attack Detection In Sdn-Enabled Mobile Wireless Networks, Ishita Sharma, Satyam Agarwai, Shashi Shekhar Jha, Sumit Chakravarty

Faculty Articles

Attacks on network components and devices pose a significant threat to service continuity, necessitating robust detection mechanisms. This paper presents a Distributed Denial of Service (DDoS) attack detection framework tailored for heterogeneous mobile wireless networks within a Software-Defined Networking architecture. A two-tier model is proposed: localized attack detection at access points (APs) using a Multi-Layer Perceptron (MLP) classifier, and centralized detection under mobility at the controller using a Long Short-Term Memory (LSTM) model. The system incorporates novel traffic features such as flow count, speed of source IP, source and destination IP address entropy, proportion of bidirectional flows, and handover frequency, …

Vacuum Modification Of The Surface Properties Of T15k6 Hard Alloy By Plasma–Chemical Synthesis Of Tin-Cu Coatings, Aleksandr Semenov, Dmitriy Tsyrenov, Nikolay Ulakhanov, Irina Semenova, Undrakh Mishigdorzhiyn, Wen Ma, Simon C. Tung, George E. Totten

Mechanical and Materials Engineering Faculty Publications and Presentations

The design and main parameters of a plasma–chemical reactor containing two compartments are presented. One compartment houses a vacuum-arc evaporator, while the other houses a planar magnetron. The compartments are separated by a diaphragm with a dosing slot for injecting copper vapor into the TiN synthesis compartment. The conditions for the synthesis of superhard TiN-Cu composite coatings are experimentally determined. Based on established process parameters for TiN synthesis in a nitrogen-containing plasma by Ti evaporation using a vacuum-arc discharge, it is proposed to apply TiN-Cu coatings by injecting Cu vapor into the TiN synthesis area and sputtering Cu using a …

Extraction And Interpretation Of Eeg Features For Diagnosis And Severity Prediction Of Ad And Ftd Using Deep Learning, Tuan Vo

Electronic Theses and Dissertations 2020 - Present

Alzheimer’s disease (AD) is the most common form of dementia and is characterized by progressive cognitive decline and memory impairment. Frontotemporal dementia (FTD), the second most prevalent form, primarily affects the frontal and temporal lobes and often leads to changes in personality, behavior, and language. Due to overlapping clinical symptoms, FTD is frequently misdiagnosed as AD. Electroencephalography (EEG) offers a portable, non-invasive, and cost-effective method for studying brain activity; however, its diagnostic utility for differentiating dementia subtypes is limited by signal complexity and noise. In this dissertation, I propose an EEG-based feature extraction framework that leverages deep learning to identify …

Passenger Autonomy In Airport Systems: Integrating Accessibility, Spatial Design, And Technology To Improve Operational Efficiency, John Michael Schmitz

Honors Projects

Airports are among the most complex operational environments in modern transportation, requiring the coordination of passenger movement, security processes, and infrastructure under significant time constraints. Although there have been many advancements in aviation, most passengers continue to experience high levels of stress and confusion while trying to navigate airport terminals. This paper argues that operational efficiency in airport systems is achieved by increasing  passenger autonomy through the utilization of accessible design, spatial legibility, and new emerging technologies. This paper takes note of some foundational theories that drove urban design and cognitive psychology, including Lynch’s concept of imageability, Passini’s theory of …

Sdn Controller For Distributed Quantum Computing, Firas Selmi

Masters Theses

Quantum networks promise transformative capabilities for computation [1], but current hardware remains limited; state-of-the-art quantum processors still operate with only a few hundred qubits [2], far below the scale required for practical applications. This limitation motivates the use of Distributed Quantum Computing (DQC), where computation is performed across multiple interconnected nodes. However, efficient DQC requires global network awareness and orchestration, a role analogous to Software-Defined Networking (SDN) in classical systems. In this work, we investigate the impact of SDN-inspired control logic on quantum networks by executing a scaled distributed implementation of Shor’s algorithm to factor N = 15 over a …

An Evaluation Of Total Navicular Implants: A Scoping Review, James Mcclure Hughes, Nicholas Belardo Obias, Amanda Killeen

School of Podiatric Medicine - Student Research

The aim of this study is to determine the efficacy and safety profile of total navicular implants based on current literature.

Navicular insults such as high-energy trauma, osteonecrosis, and Muller-Weiss syndrome may result in avascular necrosis or a critical sized bone defect, conditions that are highly difficult to manage given current treatment modalities. Total navicular implants may offer a solution to these problems. While 3D printing of implants remains investigational, its use in highly individualized cases involving the talus has had promising results with conditions like avascular necrosis, tumors, trauma, and arthritis. The navicular is unique in its attachments to …