Engineering Commons^™

Effective Prediction Of Martensite Start Temperature By Hybrid Machine Learning And Ethical A.I. In Materials Science, Agniprava Banerjee

Open Access Theses & Dissertations

The martensite start temperature Ms governs heat treatment design and mechanical property development in martensitic steel alloys. Accurate prediction of Ms from chemical composition alone would accelerate alloy development, yet existing empirical equations lack accuracy for multi-component steels and purely data-driven models provide no physically principled behavior outside their training domain. This dissertation develops a hybrid machine learning-physics framework for predicting Ms in steel alloys from composition. The MAP Cambridge dataset (1,020 cleaned records, 15 alloying elements) is processed through a five-stage cleaning pipeline and a 21-feature physics augmented representation, including the Ghosh-Olson Ms thermodynamic prediction as an explicit feature. …

Additive Manufacturing Of Spatially Variant Actuating Structures From Shape Memory Polymers., Katia Lizbeth Delgado Ramos

Open Access Theses & Dissertations

This dissertation studies the structure-processing-function relationships of additively manufactured shape memory polymer blends, with emphasis on mechanical anisotropy. Chemical exposure, thermally activated recovery, self-healing behavior, and 4D printed functional response. Two polyester-based blends were studied: a binary blend composed of polycaprolactone and thermoplastic polyurethane (PCL/TPU) blend, and a ternary blend composed of polycaprolactone/thermoplastic polyurethane/ polylactic acid (PCL/TPU/PLA) blend. The materials were melt-compounded using a twin-extruder to produce filament for fused filament fabrication (FFF). Specimens were fabricated using four different raster orientations, 0°,90°, 0/90°, and 45°, to investigate the influence of processing architecture and composition on the mechanical performance, recovery behavior, …

An Approach To Incorporate Skid Resistance Into Balanced Asphalt Mix Design Framework, Sandeep Reddy Gottam

Open Access Theses & Dissertations

The Balanced Mix Design (BMD) process aims to achieve an economical blend of aggregates, binder, and additives for satisfactory performance against rutting and cracking-related distresses, compared to volumetric design methods. Although the BMD process improves the structural performance of pavements, functional performance is essential for the comfort and safety of road users. Road user comfort is influenced by pavement distresses, while road user safety is largely determined by the skid resistance (frictional resistance) of the pavement. The aim of this dissertation was to incorporate skid resistance into the BMD framework through an approach. To develop an approach that integrates with …

First-Principles Study Of Uranium Mononitride, Roy Noe Herrera Navarro

Open Access Theses & Dissertations

This thesis presents a first-principles investigation of uranium mononitride (UN), withemphasis on the connection between uranium 5f electron correlation and defect stability. Electronic-structure calculations were performed within density functional theory using the Vienna Ab initio Simulation Package. Exchange-correlation effects were treated within the generalized gradient approximation, and a Hubbard correction was applied to the uranium 5f manifold. The adopted Hubbard parameter was motivated by first-principles linear-response analysis and considered in the broader context of DFT+DMFT descriptions of correlated uranium systems, including recent interpretations of UN as a Hund-metal system. Bulk UN was studied in unit-cell and 2 x 2 x …

Additive Manufacturing Of Roman Concrete-Inspired Self-Healing Polyvinyl Alcohol-Polylactic Acid Blends: Influence Of Composition, Processing Temperature, And Raster Pattern On Print Quality And Mechanical Performance, Stephanie Moreno

Open Access Theses & Dissertations

This study investigates development of Roman concrete-inspired self-healing polymer blends based on polyvinyl alcohol (PVA) and polylactic acid (PLA) for the additive manufacturing (AM) process of fused filament fabrication (FFF). The motivation for this work stems from the need to enhance durability and functionality of biodegradable polymers while addressing environmental concerns associated with plastic waste. Inspired by the multifunctional and hierarchical architecture of Roman concrete. PVA is integrated as a hydrophilic, sacrificial phase similar to lime clasts, embedded inside a PLA-rich structural matrix to promote physical interaction and water-activated self-healing behavior. Binary PVA:PLA blends with ratios of 5:95, 10:90, 20:80 …

Bead-Weaved Layered Prints For Improved Interlayer Adhesion In Additive Manufacturing, Arianna Isabel Villegas

Open Access Theses & Dissertations

Additive manufacturing (AM) with polymer materials has widespread adoption across industries due to its numerous benefits: rapid prototyping, material variety, cost efficiency, manufacturing complexity, on-demand production, and sustainability. AM enables fast prototyping, diverse material choices, and cost savings by eliminating tooling and reducing waste. It excels at producing intricate, lightweight designs. On-demand production reduces inventory and lead times. Polymer AM contributes to sustainability by minimizing material waste. These advantages make polymer AM popular in aerospace, automotive, healthcare, and consumer products industries. Despite these advantages, interlayer adhesion has been a reoccurring issue with AM of polymer materials. With polymer printing, there …

Bridging Industry And Academia In Engineering Leadership Education: Using Q Methodology To Identify The Viewpoints Of Engineering Professionals On Effective Engineering Leadership, Pamela Edith Campos Valles

Open Access Theses & Dissertations

Background: Engineering leadership has been recognized as a key professional skill by the U.S National Academy of Engineering, leading to increased attention and integration in engineering education research and development. The perception and recognition of leadership within the engineering field remains limited by the widespread definitions of leadership and limited characterization of engineering leaders. The Contextual Engineering Leadership Development framework is grounded on a discipline specific definition of engineering leadership and approaches to leadership development derived from engineering undergraduate programs. The use of this framework provides the opportunity to describe what engineering leaders prioritize, enabling the identification and characterization of …

Mitigating Inertial Measurement Unit Drift In Quadcopter Trajectory Tracking Using Kalman Filter Sensor Fusion With Global Positioning Measurements, Juan Sandro Caballero Aguilar

Graduate Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) like quadcopters are widely used in civilian and military applications such as farming, photography, search and rescue missions, and autonomous navigation and motion. The performance and stability of these systems depend on accurate state estimation, which provides real-time information about the vehicle’s position, velocity, and orientation. However, achieving reliable state estimation is challenging due to sensor noise, measurement uncertainty, and inaccurate modeling. Common navigation sensors such as the Global Positioning System (GPS) and Inertial Measurement Units (IMUs) exhibit complementary characteristics. GPS provides absolute position measurements but suffers from noise, multipath effects, and low update rates, while …

Development And Characterization Of 1200v And 1700v Sic Schottky Barrier Diode For Power Electronics Applications, Nur-E-Afra Anika

Graduate Theses and Dissertations

The growing demand for energy-efficient, high performance power electronics in applications such as renewable energy systems, electric vehicles, industrial motor drives, and aerospace has accelerated the development of wide bandgap semiconductors like Silicon Carbide (SiC). This thesis focuses on the development and characterization of 1200V and 1700V SiC Schottky Barrier Diodes (SBDs), focusing on their performance optimization for power electronics applications. The key parameters and figure of merits for SiC Schottky barrier diode (SBD) is discussed. Commercially available 1200V and 1700V SBDs are characterized and key design parameters like drift region length, active area, and carrier concentration are extracted. The …

Electrical Resilience In Water Treatment Plants: An Extreme Weather And Lightning Protection Study, Genesis Martinez

Theses and Dissertations

Water treatment plants (WTPs) are vital infrastructure systems that depend on sensitive electrical, electronic, and control equipment to ensure the continuous supply of safe drinking water and effective wastewater treatment. As global temperatures rise and climate change accelerates, the frequency and intensity of extreme weather events—such as hurricanes, flooding, and increased lightning activity—are becoming more pronounced. These events pose significant risks to the electrical resilience of water treatment facilities, often leading to power outages, equipment failures, grid instability, and prolonged service disruptions. This report explores the impacts of extreme weather, with a particular focus on lightning and electrical surges, on …

From Reactive To Predictive: A Hybrid Trust-Mediated Adoption Framework For Data-Driven Maintenance In Distributed-Authority Aviation Environments, Dustin J. Foote

International Journal of Aviation, Aeronautics, and Aerospace

Modern aviation maintenance operates within increasingly data-intensive technological environments, yet the operational integration of predictive maintenance into routine decision-making remains inconsistent across sectors. Contemporary aircraft incorporate centralized maintenance computers and condition monitoring architectures capable of fault aggregation, exceedance capture, and trend-based data collection. Although prognostics and health management research continues to advance detection and prediction methods, implementation outcomes often depend on factors beyond analytical performance alone.

This paper examines predictive maintenance adoption in distributed-authority aviation environments and argues that constraints emerge less from sensing capability than from organizational structure, decision authority dispersion, and institutional trust dynamics. For purposes of analysis, …

Digital Twin–Oriented Certification Architecture For Advanced Air Mobility, Daniel Pleffken

International Journal of Aviation, Aeronautics, and Aerospace

Advanced Air Mobility (AAM) systems introduce certification challenges associated with distributed propulsion, increasing software reliance, and tightly coupled architectures. These characteristics evolve within regulatory environments that are still adapting to emerging vehicle concepts. While digital engineering practices are increasingly adopted during system development, certification workflows remain largely document-centric, limiting lifecycle traceability and consistent reasoning about change impacts as designs and regulatory interpretations evolve. This paper proposes a Digital Twin–oriented certification architecture that integrates regulatory knowledge, system representations, Means of Compliance (MoCs), and verification artifacts within a unified model-based environment. The architecture is organized around four elements: regulatory structuring, Model-Based Systems …

Porous Hydrophobic Adsorbent Coatings For Carbon Dioxide Capture, Samuel Babatunde Olushola

Theses and Dissertations

This work presents the development of a porous, hydrophobic zeolite 13X coating for the separation of carbon dioxide (CO₂) from flue gas or natural gas. Zeolite 13X was combined with yeast, glucose, and sodium alginate as pore-forming agents, and with polytetrafluoroethylene (PTFE) and Polydimethylsiloxane (PDMS) as hydrophobicity-inducing agents to enhance water resistance while maintaining CO₂ access to the adsorbent. The study explored PTFE/13X mass ratios ranging from 0 to 2.33 to investigate the interplay between hydrophobicity and CO₂ uptake. The wettability of the coating was characterized by using a temporal water contact angle (WCA) measurement. Increasing …

Range Extension Of Electric Propulsion General Aviation Aircraft Using Solar Technology, Mary Kathryn Shultz

Theses and Dissertations

Alternative propulsion technologies in aviation have been a long-time topic of interest as operators aim to bypass growing fuel prices and meet environmental sustainability requirements set globally. Research regarding alternative propulsion technologies is primarily centered around marginally improving efficiency of combustion systems or large-scale implementation of novel technologies. This research evaluates the feasibility of implementing solar-integrated propulsion for general aviation aircraft to extend range through a comparison of full-electric, hybrid solar, and internal combustion engine propulsion systems. This evaluation of existing technology by range analysis indicates that hybrid solar‑electric propulsion is viable primarily for short‑range training and recreational aircraft, rather …

Aircraft Fault Detection Via Weight And Bias Analysis Of A Custom First Neural Network Layer, George Harrison Chen

Theses and Dissertations

Fault detection in aircraft is traditionally handled through redundant hardware and comparison algorithms to detect failures. Alternatives like model-based residual generation and data-driven approaches such as supervised fault classification and unsupervised anomaly detection have been explored, but they suffer from practical limitations; model-based methods require accurate system models, and data-driven methods have large constraints on the data limiting scalability and adaptability. This work presents a purely data-driven neural network architecture featuring a custom first layer designed for real-time fault detection where the weights and biases of this layer are used to detect faults. The network requires zero supervision and complements …

Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante

Theses and Dissertations

This thesis presents the design and simulation of an 8-tube single-ring anti-resonant hollow-core fiber for sensing applications, with particular emphasis on methane gas detection at the fundamental absorption wavelength of 3.3 µm. Conventional solid-core silica optical fibers exhibit strong multi-phonon material absorption beyond 2.5 µm, rendering them fundamentally unsuitable for efficient light guidance and direct gas sensing at mid-infrared wavelengths. Anti-resonant hollow-core fibers overcome this limitation by guiding light predominantly through an air-filled hollow core via the anti-resonant reflecting optical waveguide mechanism, in which the thin silica glass walls of the cladding tubes act as Fabry-Pérot etalons that confine the …

Adaptive Artificial Potential Field Guidance And Control For Autonomous Docking With Uncooperative And Unknown Spacecraft, Steven Holmberg

Theses and Dissertations

The increasing demand for on-orbit servicing (OOS), active debris removal (ADR), and space domain awareness (SDA) missions has increased the need for autonomous spacecraft rendezvous and proximity operations (RPO) with uncooperative and unknown targets. Traditional guidance and control methods are typically designed for cooperative systems with known geometry and state information. This work builds on previous research to develop and evaluate an artificial potential field (APF)-based control framework capable of autonomous operation with minimal prior target knowledge and applicability to both relatively static and tumbling spacecraft.

The proposed APF formulation incorporates established safety constructs from cooperative docking systems, including an …

Moon Adaptive Technology For Extraterrestrial Architectural Robotics (Matear), Candela Noemi Solis Zampini

Theses and Dissertations

The Moon Adaptive Technology for Extraterrestrial Architectural Robotics (MATEAR) focuses on the development of an autonomous robotic system capable of providing structural building blocks directly from lunar regolith. As a sustained human presence on the Moon becomes a necessity, the costly and limited payload capacity associated with transporting construction goods from Earth creates a critical challenge. MATEAR addresses this problem through in-situ resource utilization (ISRU), integrating a regolith processing system onto a remote operated vehicle. The proposed system is designed to collect lunar dust, mechanically compact the material, and apply thermal treatment to enhance cohesion through sintering. These regolith-made bricks …

Design And Development Of A Passive Dust Protection System For Lunar Docking Operations, Simon Thengvall

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

Lunar docking systems face a unique set of environmental conditions that can create significant challenges for mechanical design. Among these, the abrasive nature of lunar regolith can impair the kinematic function of traditional terrestrial mechanisms as well as contaminate critical spacecraft components such as environmental seals, causing them to fail. For crew-rated docking systems, failure of these systems not only threatens mission success, but also crew safety, so dust protection is crucial for docking components. To address the concerns of regolith intrusion, the Simple External Attachment for Lunar Openings (SEALO) is developed as a key architecture for mechanism evaluation when …

Clear-Air Turbulence Climatology And Trends, Liam Rodgers, Mark Sinclair

Publications

Clear‑air turbulence (CAT) is a major aviation hazard that occurs near airline cruising altitudes in both cloud and cloud‑free environments. Its lack of a distinct visual signature makes detection and avoidance difficult. CAT is associated with wind shear near jet streams, gravity waves, and Kelvin–Helmholtz instability and may be further enhanced by climate change. This study examines the climatology, spatial distribution, seasonal variability, and trends of CAT over the contiguous United States.

Pilot Reports (PIREPs) from 2001–2025 between 100 and 400 hPa are analyzed alongside jet stream, shear, and stability diagnostics derived from NCEP–NCAR Reanalysis data. Proxies such as inverse …

Multiscale Architecture Governs Stability In Suction-Actuated Variable Stiffness Catheters, Sheridan Lee

McKelvey School of Engineering Graduate Student Theses & Dissertations

Endovascular procedures require devices with widely varying mechanical properties: flexibility for navigating tortuous vessels and rigidity for stable therapeutic delivery. Suction-actuated variable stiffness sheaths address this challenge by incorporating axial wire string arrays that mechanically couple under suction to increase flexural rigidity. However, prototype devices achieve stiffening ratios below theoretical predictions, suggesting that interlayer mechanics and string positioning play a critical role. This study investigates whether interweaving polytetrafluoroethylene (PTFE) tape within the string array enhances flexural rigidity modulation and curvature stability. Prototype devices with varying wrap configurations were fabricated and evaluated using flexural testing, curvature stability testing, and mathematical modeling. …

Computational Fluid Dynamics (Cfd)-Based Performance Prediction Of Transcatheter Microvascular Plugs In Single-Ventricle Patients, Zhuhuan Zou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Transcatheter palliation using fenestrated Modified Micro Vascular Plugs (MVP) has emerged as a promising, minimally invasive alternative to surgical pulmonary artery banding (PAB) for high-risk neonates with single-ventricle physiology. However, clinical applications are currently limited by the difficulty in predicting the resulting pulmonary-to-systemic flow ratio () and the lack of a standardized approach for selecting the optimal fenestration size. This study utilizes patient-specific computational fluid dynamics (CFD) to quantitatively evaluate the impact of varying fenestration diameters on circulatory balance. Patient-specific 3D models of the pulmonary artery (PA) were reconstructed from imaging data for two clinical cases using SimVascular. Transient CFD …

Design Of An Extensible And Scalable Data Acquisition System For Pulse Shape Discrimination, Prince John

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis presents the design and development of a highly scalable, end-to-end data acquisition (DAQ) system for nuclear physics experiments that can be deployed in configurations ranging from a few to thousands of detector channels. The system is built as an extensible platform composed of modular 16-channel chipboards that support a wide range of scintillator and detector types and perform real-time, on-board data sparsification and pulse-shape processing. Three versions of the chipboard have been fabricated to date.

The DAQ architecture is based on a family of analog pulse-shape-processing application- specific integrated circuits (ASICs) developed by the IC Design Laboratory at …

Conditioning Hierarchical Diffusion Transformers On Rf Circuit Parameters, Ethan Morton

McKelvey School of Engineering Graduate Student Theses & Dissertations

As modern ML techniques have become increasingly advanced, they have begun to be integrated into wireless RF systems for classification, identification, and spectrum management. Deep Neural Networks (DNNs) enable RF system operators and designers to design more flexible systems with greater robustness to errors and attacks. However, neural networks require significant amounts of properly annotated data to train. Current data labeling methods lack the ability to obtain reliable true labels for circuit properties such as carrier frequency offset (CFO), power amplifier (PA) non-linearity, and in-phase/quadrature (IQ) imbalance. This thesis investigates the efficacy of a novel architecture, RF-Diffusion, for generating high-quality …

Post-Vote Tampering In Nigerian Elections And The Role Of Blockchain-Enabled Electoral Systems, Ransome Chukwubuikem Enechukwu

Electronic Theses and Dissertations

Post-vote tampering during the collation and transmission of election results remains a persistent challenge in Nigerian elections, enabling manipulation of already-cast votes and weakening public trust in electoral outcomes. Existing technological interventions, including biometric voter accreditation and digital result transmission systems, improve voter authentication but do not adequately secure the post-vote result collation process. This thesis proposes a blockchain-enabled framework designed to protect the integrity of election results during the collation and transmission stages. Using a Design Science Research methodology, the study develops a permissioned blockchain framework based on Hyperledger Fabric that records polling-unit results as immutable ledger entries and …

A Machine Learning Framework For Early-Stage Cost Estimation Of Transportation Projects, Pritom Paul

Electronic Theses and Dissertations

To address the limitations of traditional planning-level cost estimating methods, such as reliance on statewide averages, heavy reliance on engineering judgment, and high levels of inaccuracy, this study developed two data-driven frameworks and corresponding tools. The first framework focused on resurfacing projects and used treatment-specific simple linear regression based on lane miles and geographic location. The second addressed a broader group of construction projects and used multiple linear regression with project length, route type, and right-of-way cost as key predictors. In both frameworks, the final estimates are computed by aggregating multiple estimates produced by county-, region-, and state-level models. The …

Enameling Coating Of Pipes: Thermal Proprieties And Corrosion Tests, Signo Reis, Genda Chen, Mike Koenigstein, Liang Fan

Materials Science and Engineering Faculty Research & Creative Works

Enamel coating on pipelines can be done in several ways such as the wet process, plasma spray, and electrostatic process. Wet process requires little capital expenses and provides an acceptable finish for industrial applications particularly when the part to be coated is small. Electrostatic process of enamel powder is most promising to coating large pipelines in field conditions. The enamel coating applied by the electrostatic process is very consistent and smooth since each particle is glass only. However, the powder is very fragile until fired and the charge retention is lowered in high humidity conditions. Coupons cut from a full-size …

Evaluation Of Iron-Phosphate Glass–Ceramic Waste Form For Electrorefiner Salt Waste Simulant Dechlorinated With Phosphoric Acid, Harmony Werth, Paige Murray, Lucas Greiner, Jade Beland, Charmayne Lonergan, Brian Riley, Krista Carlson

Materials Science and Engineering Faculty Research & Creative Works

The importance of glass and glass–ceramic nuclear waste forms has been reaffirmed in recent years by the growing interest in nuclear power as a reliable energy source. Determination of processing methods for the disposal of halide-containing wastes will be essential for the advancement of nuclear technologies such as non-aqueous fuel reprocessing. Phosphate-based dechlorination and subsequent vitrification of radioactive salt waste into an iron-phosphate waste form have been identified as a potential processing scheme for electrochemical processing waste. The impact of H₃PO₄-based dechlorination of complex salt mixtures on the vitrification process and structure of the final iron-phosphate …

Effect Of Composition On Grain-Boundary Chemistry And Fracture Behavior In High-Entropy Carbides, Caleb Schenck, Marium Mostafiz Mou, Elizabeth Pritchett, Fu Yun Tsai, Josephine Hartmann, Michael Lastovich, Sam Daigle, Kayla Yano, Matthew J. Olszta, Sanjit Bhowick, Elizabeth Kautz, Gregory E. Hilmas, William G. Fahrenholtz, Donald W. Brenner

Materials Science and Engineering Faculty Research & Creative Works

High-entropy carbides (HECs) are often treated as a single material class defined by configurational entropy; however, their properties are governed by composition-specific defects and grain-boundary chemistry. This study demonstrates that substituting a single element can qualitatively change grain-boundary structure and fracture behavior in HEC ceramics. Two HECs, (Cr,Hf,Ta,Ti,Zr)C (HEC-Cr) and (Hf,Ta,Ti,W,Zr)C (HEC-W), were examined via electron microscopy, atom probe tomography, and molecular dynamics simulations. Simulations predict preferential segregation of Cr, W, and Zr to grain boundaries. Experiments confirmed Cr enrichment at grain boundaries and the formation of W-rich nanograins along boundary networks. Mechanical testing revealed that these compositional differences translated …

Evaluating The Integration Of Bio-Based Waste Into Cement Production: A Pathway To Sustainable Building, Anja Terzić, Suzana Filipović, Adriana Peleš Tadić, Jelena Živojinović, Ivana N. Jelić, Nina Obradović, William G. Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Rapid urbanization has increased the demand for building materials, depleting natural resources used in cement production and prompting the use of alternative and waste materials. This research verifies that eggshell powder waste can fully replace limestone in clinker synthesis. Five clinkers were produced using eggshell powder, aluminum sources (bentonite, zeolite, fly ash, and kaolinitic–illitic clay), Fe-slag, and quartz sand, with mechanical preprocessing (10–30 min) before sintering at 1300 °C. Experimental tests assessed the effects of mix design and mechanical activation on clinkerization, phase formation, temperature, and mechanical properties. XRD, FTIR, and SEM/EDS confirmed consistent phase compositions and primary cement minerals. …