Engineering Commons^™

Development And Optimization Of A Deep Level Transient Spectroscopy System, Samuel Ruiz

Open Access Theses & Dissertations

Deep-level transient spectroscopy (DLTS) remains one of the most widely used techniques for identifying electrically active defects that affect leakage current, carrier lifetime, and overall reliability in semiconductor devices. Legacy boxcar or capacitance meter implementations, however, often struggle with limited signal-to-noise ratio, labor-intensive data collection, and poor adaptability across diverse material systems. This thesis presents the design and optimization of a semi-automated, lock-in-amplifier-based DLTS platform. By pairing a Zurich HF2LI with PID-controlled cryogenic sweeps, precision signal generation, and MATLAB driven acquisition and processing scripts, the system will (i) enhance SNR through phase-sensitive detection, programmable low pass filtering, and parasitics calibration; …

Image And Signal Processing Methods For Clinical Decision Support: Reference-Based Lung Segmentation On Chest X-Rays And Ecg-Based Study Of Acute Hyperkalemia Using Machine Learning, Basavarajaiah Shanmukhayya Totada

Open Access Theses & Dissertations

ABSTRACT

Study-I: An Image Processing Pipeline for Reference Guided Lung Region Detection in Chest Radiographs with Shape Similarity Matching Accurate and reliable segmentation of the lung region in chest X-ray (CXR) images is essential for computer-aided diagnosis (CAD) systems, particularly in the early detection and monitoring of lung disorders. Traditional segmentation techniques often rely on manual annotations, limiting scalability and adaptability. The proposed reference-guided approach selects the most similar healthy CXRs dynamically, ensuring flexibility while benefiting from dataset-specific reference images. Building upon prior approaches that utilize shape similarity-based selection and SIFT-flow, this study introduces a fully automated segmentation pipeline that …

Advancing Aerospace Materials: 3d Printing Of Fiber Reinforced Cyanate Ester Ipns And Uhtcmcs, Saqlain Zaman

Open Access Theses & Dissertations

Additive manufacturing (AM) is rapidly reshaping the landscape of advanced materials for aerospace, hypersonic, and extreme-environment systems. However, AM of high-temperature polymer and ceramic composites, especially those reinforced with continuous or aligned fibers, remains limited by challenges in rheological control, in situ fiber impregnation, curing compatibility, densification, and achieving directional multifunctional properties. This dissertation advances a unified Direct Ink Writing (DIW) framework enabling the processing of architected, high-performance composite materials across polymer and ceramic systems. Three research thrusts collectively establish scalable pathways for fabricating fiber-reinforced cyanate ester interpenetrating polymer networks (IPNs) and ultra-high-temperature ceramic matrix composites (UHTCMCs). First, a dual-curable …

Application Of Natural Language Processing And Machine Learning For Analyzing Mining Accident Reports And Automating The Process Of Root Cause Analysis, Siddhartha Agarwal, Y. P. Chugh, Atul Singh, Vikram Sakinala, Ayan Mukherjee, Balbir Prasad, Cihan Dagli, Yuhao Zou

Engineering Management and Systems Engineering Faculty Research & Creative Works

Coal mining accidents are a major concern worldwide, necessitating effective safety measures and comprehensive analysis to prevent future accidents. Our proposed solution is the first attempt for Indian mines, inspired by the potential of Natural Language Processing (NLP) that can read and analyze vast repositories of accident records in seconds. In combination with machine learning (ML), NLP algorithms can extract unstructured text by eliminating manual data entry errors, reading poorly scanned reports, and understanding multiple versions of the event and cluster documents based on types that would otherwise take months to collate. In the case of accident records, it can …

Concrete Masonry Unit Construction: Creating Educational Modules On Sustainability, Eric Dam

Construction Management

Concrete Masonry Units are one of the most widely used building materials due to their durability, fire resistance, low maintenance, and specifications. With the growing trend for sustainable construction, it is necessary to teach students how CMUs can contribute to improving environmental performance and dive deeper into multiple resource efficiency. This project developed an instructional module that introduces CMU materials, reviews performance and durability attributes of these materials, and how they are linked to well-known rating systems. The final module includes a presentation, three assignments, and one quiz that will reinforce student learning and refresh industry professionals' knowledge. The following …

Life Cycle Assessment Of A Prefabricated Modular Timber Building, Bryan Mai

Construction Management

Traditional concrete construction carries a high carbon footprint, motivating interest in lower-impact alternatives such as prefabricated modular timber systems. This project conducts a process-based life cycle assessment (LCA) using OpenLCA to evaluate the environmental impacts of a modular timber building. Material quantities from major processes were modeled as flow inputs and converted into standardized OpenLCA units. Impact categories—including acidification potential, human toxicity, and energy/resource use—were analyzed to determine which materials and processes contribute most to overall environmental burden. Results show that transportation and plumbing materials drive the largest acidification impacts, while interior finishes dominate human toxicity. This LCA establishes a …

Building Kit For K-8 Education: An Introduction To Construction Fundamentals, Marc Joynt

Construction Management

Introducing construction concepts to young students requires tools that are both engaging and easy to use, which led to the development of a laser-cut building kit designed for K–8 classrooms. The process began with hand-drawn sketches to establish a simple, age-appropriate structure. The design was then modeled in AutoCAD, where each individual component was drafted for fabrication. After completing the digital model, the files were transferred into Rhino and organized by layer to ensure accurate communication with the laser cutters used to produce the final basswood pieces. Throughout the project, challenges such as material limitations, tolerance adjustments, and simplifying complex …

Effects Of Wc Additions On The Phase Formation Of (Hf,Nb,Ta,Ti,Zr)C-(Hf,Nb,Ta,Ti,Zr)B2 High Entropy Dual Phase Ceramics, Rubia Hassan, William G. Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

High entropy dual phase (Hf,Nb,Ta,Ti,Zr)C-(Hf,Nb,Ta,Ti,Zr)B2 ultra-high temperature ceramics were produced from powders synthesized by boro-carbothermal reduction. Systematic additions of 2.5 wt%, 5 wt%, and 10 wt% WC were incorporated after powder synthesis. Additions of 2.5 wt% and 5 wt% WC dissolved into the host ceramics, resulting in complete solid solution formation and nearly full densification. In contrast, a secondary monoboride phase evolved for the composition with 10 wt% WC, in addition to the main high entropy carbide and diboride phases. Thermodynamic analysis revealed that WB formation was favorable for WC additions in the presence of metal diborides at the sintering …

Micro/Nanomechanical Properties Of Top-Seeded Melt Grown Ybco Single Crystals Determined Using Depth Sensing Indentation, Ugur Kolemen, Cafer Mert Yesilkanat, Fikret Yilmaz, Fatih Dogan, Orhan Uzun

Materials Science and Engineering Faculty Research & Creative Works

Mechanical properties of the bulk YBa2Cu3O7-x (YBCO) single crystal superconductor, prepared by using the Top Seeded Melt Growth (TSMG) method, were determined. Property measurements were conducted by the nanoindentation method under various loads and the micro indentation method at different temperatures. Hardness (H) and reduced elastic modulus (Er) values were calculated by using the Oliver–Pharr method. According to hf/h max values found from load- displacement curves, there is a sink in behavior around outer rim of the indents that was confirmed by atomic force microscopy (AFM) analysis. Nanoindentation analyses conducted on upper section, middle section and subsection revealed that all …

Effect Of Powder Recycling On Powder Characteristics And Mechanical Properties Of Materials Produced By Laser Powder Bed Fusion (Lpbf): A Review, Mihiretu Ganta, Marta Kurek, Arezoo Emdadi, Tadeusz Łagoda, Marek Pagáč

Materials Science and Engineering Faculty Research & Creative Works

As the Laser powder bed fusion (LPBF) process advances toward industrial-scale production, the sustainability of metal powder feedstocks has become a focal point of research. The powder recycling approach, while environmentally and economically favorable, results in a series of physicochemical variations that could compromise the part quality. The resulting variation in powder characteristics with powder recycling could affect the powder layer density and melt pool dynamics, resulting in defect formation and hindering the structural integrity of LPBFed parts. These alterations pose significant constraints to mechanical performance, particularly in fatigue-sensitive applications where even minor imperfections can substantially reduce service life. The …

Variable-Temperature Plasmonic High-Entropy Carbides, Simon Divilov, Sean D. Griesemer, Robert C. Koennecker, Michael J. Ammendola, Adam C. Zettel, Hagen Eckert, Jeffrey R. Shallenberger, Xiomara Campilongo, William G. Fahrenholtz, Arrigo Calzolari, Douglas E. Wolfe, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Effective thermal management at variable and extreme temperatures face limitations for the development of novel energy and aerospace applications. Plasmonic approaches, shown to be capable of tailoring black-body emission, could be effective if materials with high-temperature and tunable plasmonic resonance were available. Here, we report a synergy between experimental and theoretical results proving that many high-entropy transition metal carbides, consisting of four or more metals at equal molar ratio, have plasmonic resonance at room, high (>1000∘C) and variable temperatures. We also found that these high-entropy carbides can be tuned and show considerable plasmonic thermal cycling stability. This paradigm-shift approach …

Comparative Analysis Of Emergent Behaviors Of Three Drone Swarm System Models For Targeting Using Agent-Based Modeling And Simulation, Arsenio T. Gumahad Ii

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation introduces a novel computational simulation framework for evaluating the emergent behaviors of three swarm drone models using Agent-Based Modeling and Simulation (ABMS). The three swarm models are a Leader-Follower swarm model based on Bruckstein's antline theory, a Flocking model based on a simplified Reynolds 'Boids’ model, and a Stigmergic model with pheromone-based coordination. The primary objective of the simulation is to evaluate the performance of these models in delivering a user-defined number of drones of each type to a target area of interest in four separate scenarios, resulting in 50,000 separate simulation trials. Each scenario was structured to …

Human Identification And Action Recognition Using Small Data And Deep Domain Adaptation, Alexander M. Glandon

Electrical & Computer Engineering Theses & Dissertations

Human identification and human action recognition problems are two important research areas for real-world security and surveillance applications. In both human identification and action recognition, it is necessary to operate by collecting small datasets in the field, possibly in a short time window of observation. This dissertation studies and develops computational modeling and high-performance machine learning (ML) and deep learning (DL) models for human identification and human action recognition using small amounts of data. These methods and computational models may be useful for different security and surveillance applications.

This dissertation on human recognition develops a ML computational model to estimate …

A Precipitation-Hardened High-Entropy Alloy With Excellent Mechanical Properties Additively Manufactured By In-Situ Alloying, Matthew Luebbe, Shahryar Mooraj, Jonathan Poplawsky, Hans Pommerenke, Wen Chen, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Studies on precipitation-hardened high-entropy alloys (PHEAs) have demonstrated high strength, good ductility, and thermal stability, making them excellent candidates for high-temperature structural applications such as nuclear reactors. However, many complex parts for those applications would need to be produced via additive manufacturing (AM), whose rapid cooling rates and multiple heating cycles could change the microstructure of the chosen alloys and accordingly their mechanical properties. A PHEA, (Fe0.3Ni0.3Mn0.3Cr0.1)88Ti4Al8, which was developed and produced via conventional manufacturing in our previous work with high strength but low ductility, was chosen to test the effects of AM on the microstructure and mechanical properties. Scanning …

Experimental Determination Of Tnt Equivalence Values For Binary Energetic Materials, Gracie May M. James, Rachel L. Bauer, Emily M. Johnson, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

TNT equivalency quantifies the impact of energetic materials relative to TNT, aiding in safety guidelines and performance evaluations. Despite widespread use in industry, military, and research, many binary energetics lack published TNT equivalence values. This study experimentally determines TNT equivalency values for Helix, Texpak, Rimfire, Tannerite, and Kinepak using three tests: (1) plate dent, (2) reaction velocity and (3) air blast. Each test evaluates distinct aspects of energetic performance, addressing both close-in destructive power and downstream effects. Helix produced TNT equivalence values from 0.64 to 1.10, comparable to TNT, while Kinepak had lower values (0.18 to 0.58) indicating limited brisance, …

Assessing Technology Adoption In The Construction Industry, Lucas D. Gibbons

Construction Management

The construction industry is steadily integrating new technologies, yet adoption varies widely depending on company size, market sector, and internal readiness. This study examines how common technologies such as drones (UAVs), Building Information Modeling (BIM), robotics and automated equipment, laser scanning/LiDAR, AI-driven scheduling or analytics tools, and augmented or virtual reality (AR/VR) are being applied in practice, and what benefits they are delivering to construction organizations. To better understand the factors shaping adoption, a survey was administered to members of the CMAC (Construction Management Advisory Council) board representing a range of contractors and industry stakeholders. The survey assessed current technology …

Design And Assessment Of A Single-Blade Rotary Wing For Use In Vertical Takeoff And Landing (Vtol) Aircraft, William C. Mcmasters

Mechanical & Aerospace Engineering Theses & Dissertations

A single-bladed propeller was designed to determine its efficacy in increasing efficiency of quadplane aircraft in the cruise configuration while still providing sufficient vertical lift for the vertical takeoff portion of flight. Aerodynamic theory predicts higher efficiency for single-blade propellers, resulting in a lower power requirement. A counter-weighted single-blade was modeled after a 10x5 model aircraft propeller used in small unmanned vehicles with a steel counterweight to balance centrifugal forces. The propeller was tested in the ODU wind tunnel to determine performance at various Advance Ratios (J). The research suggests that single-blade propellers show comparable performance compared to two-bladed propellers …

Separating The Control Of Moving And Holding In Human Post-Stroke Arm Paresis, Alkis M. Hadjiosif, Kahori Kita, Scott T. Albert, Robert A. Scheidt, Reza Shadmehr, John W. Krakauer

Biomedical Engineering Faculty Research and Publications

Moving and holding-still (holding) have been posited to be separately controlled. The paretic arm after stroke exhibits different abnormalities during rest vs. movement, providing an opportunity to ask whether control of these behaviors is independently affected in stroke. We quantified resting postural abnormalities in human stroke patients by measuring their biases in force production as they held their hand still in various locations in a planar workspace and then assessed whether these resting force biases influenced reaching in the same workspace. Patients displayed marked resting force biases at each location, even when the arm was supported. However, these …

Effective Transfer Of Tumor Annotations From Hematoxylin And Eosin To Fluorescence Images Of Breast And Lung Tissues, Tianling Niu, Emi Ampo, Julie M. Jorns, Mollie Patton, Tongtong Lu, Dong Hye Ye, Tina Yen, Bing Yu

Biomedical Engineering Faculty Research and Publications

Significance: Accurate transfer of annotations from histological images to fluorescence images is essential in developing deep learning (DL)-based optical imaging systems for intraoperative assessment of tumor margins. Manual annotation is time-consuming, prone to interobserver variability, and impractical for large-scale datasets.

Aim: We present a semi-automated method that can effectively transfer tumor annotations from pathologist-annotated hematoxylin and eosin (H&E) images to fluorescence images captured using microscopy with ultraviolet surface excitation (MUSE). This method is not intended for intraoperative use but rather to facilitate the creation of annotated datasets for DL model development.

Approach: Our semi-automated method consists of nonrigid image registration, …

Data Driven Design Of Ultra High Performance Concrete Prospects And Application, Bryan K. Aylas-Paredes, Taihao Han, Advaith Neithalath, Jie Huang, Ashutosh Goel, Aditya Kumar, Narayanan Neithalath

Electrical and Computer Engineering Faculty Research & Creative Works

Ultra-high-performance concrete (UHPC) is a specialized class of cementitious composites that is increasingly used in various applications, including bridge decks, connections between precast components, piers, columns, overlays, and the repair and strengthening of bridge elements. The mechanical and durability properties of UHPC are significantly influenced by factors such as low water-to-binder ratios, the inclusion of supplementary cementitious materials (SCMs), and fiber reinforcement. Machine learning (ML) has been employed to predict the performance of UHPC and optimize its mixture designs by using various raw materials. This study first provides a comprehensive review of ML applications in UHPC, focusing on predicting workability, …

Una Animación Propia. Discurso Emancipador Desde El Cine De Animación Independiente, Elisa Martínez, Damià Jordà

GDI. Revista de investigación de Género, Diseño e Innovación

Introducción: A pesar de la temprana incorporación de las mujeres a la industria de la animación, sus roles fueron históricamente relegados a labores mecánicas, limitando su capacidad de decisión creativa. Este artículo analiza cómo el cine de animación independiente del siglo XX funcionó como un espacio esencial para las directoras que buscaban un control artístico que permitiera desarrollar discursos emancipadores. Se parte de la hipótesis de que el circuito independiente propició que las animadoras desarrollaran técnicas y narrativas alternativas que rompieron con los cánones plásticos y los preceptos ideológicos dominantes en la industria. Metodología: Mediante una metodología cualitativa, …

Per- And Poly-Fluoroalkyl Substances Fate Across California Wastewater Treatment Plants: A Meta-Analysis Of Formation, Distribution, And Persistence, Elizabeth Reineke

Master's Theses

Per- and poly-fluoroalkyl substances (PFAS) are persistent contaminants that move through municipal and industrial wastewater systems with limited attenuation. As a result, they are increasingly detected in drinking water supplies. Despite growing regulatory concern, a systems-level understanding of PFAS behavior across multiple treatment facilities and watershed settings remains incomplete. This study compiled influent, effluent, and biosolids datasets from more than one hundred California wastewater treatment plants to evaluate PFAS occurrence, transformation, and partitioning across diverse treatment configurations. Analytical steps included calculating removal efficiencies, assessing precursor-to-product oxidation, evaluating co-contaminant correlations, and grouping facilities by process design to quantify configuration-specific fate patterns. …

Design And Testing Of A Vr Escape Room Game For Philippine Martial Law History, Eric Cesar Vidal, Jr., Johanna Marion R. Torres, Jesus Alvaro Pato, Kenneth King L. Ko

Department of Information Systems & Computer Science Faculty Publications

This paper presents a Virtual Reality Educational Escape Room game where players learn about the highly divisive Martial Law period in Philippine history. We describe the game’s general design and the results of a user test to evaluate the game in terms of VR presence, immersion, and overall usability.

User Evaluation Of A Virtual Patient For Philippine Medical Education, Ma. Mercedes T. Rodrigo, Samantha Castaneda, James Alvir Maclin V. Alaan, Paolo Santino P. Caoile

Department of Information Systems & Computer Science Faculty Publications

Caladrius is a virtual patient system designed for use in Philippine medical schools. It responds to the need for medical interview training, for greater variety in teaching-learning strategies, and for culturally appropriate technologies. It has two versions: a text-only version whose interface is similar to a chat interface, and an audio version that accepts speech input and responds with speech output. In a prior test of Caladrius, users requested improved audio response time and the inclusion of different patient personalities. A subsequent version of Caladrius was created to comply with these requests. As much of the lag was attributable to …

Investigating The Performance Of Fibre Reinforced Plastic Repairs To Timber Marine Civil Structures At His Majesty’S Naval Base Devonport, Anna G. Walther

The Plymouth Student Scientist

This paper explores Fibre Reinforced Plastics (FRPs) as a composite repair method to restore and enhance mechanical properties of timber marine civil structures within the context of His Majesty’s Naval Base (HMNB) Devonport. To support this, timber composite specimens were manufactured and subjected to flexural and compressive strength tests. Comparisons are made to literature sources for initial predictions, in addition to hand calculations and Finite Element Analysis (FEA) models on SolidWorks. Data demonstrates that FRPs can be used as a cost-effective and beneficial method of repairing timber marine structures. Experimental data demonstrates an ability to restore compressive strength parallel to …

Mechanical Properties Of Sintered Lunar Regolith Simulant Lhs-1 When Moulded Under Different Temperatures And Time At Constant Pressure, Jasper Stevens

The Plymouth Student Scientist

Humans are returning to the Moon for the first time since 1972. And when they arrive, In-Situ resource Utilisation (ISRU), the philosophy of using local materials and resources will be required to help maintain a more permanent presence on the Moon. Lunar regolith is the homogenous layer of inorganic ‘soil’ that covers nearly the entire Lunar surface, making it the most readily available material for ISRU. This report investigates the effect of changing time and temperature applied to samples of lunar regolith simulant LHS-1 formed as freestanding samples under constant pressure, before sintering into a consolidated sample. Compressive testing on …

Application And Suitability Of Using Paraffin Wax In A Thermal Store For Residential Buildings In The Uk, Cameron Edwards

The Plymouth Student Scientist

Heating costs and pressure to reduce carbon emissions are rapidly increasing. A possible solution is the implementation of efficient energy storage systems for UK residential buildings. Paraffin wax-based thermal energy storage offers a promising solution due to its low-cost, high-energy density, and long-term stability. However, its low thermal conductivity significantly reduces its practicality. Multiple upgrades, such as implementing highly conductive particles and nanotubes, have been previously studied but lack the inclusion of cost-effectiveness and real-world feasibility. This paper reviews current research and develops a numerical model using the Enthalpy method and a 2D finite difference approach, utilised in Python. It …

Vacuum-Assisted Resin Transfer Moulding (Vartm): Can Ultrasonic Vibration Decrease Fill Time, Increase Composite Properties, And Reduce Void Formation, Iulia D. Precup

The Plymouth Student Scientist

This study investigated the potential of ultrasonic vibration (28 kHz) to optimize the Vacuum-Assisted Resin Transfer Moulding (VARTM) process. The aim was to assess whether introducing ultrasonic vibration during the resin infusion phase could reduce fill time, improve mechanical properties, and minimize void formation in glass fibre-reinforced polyester composites. Two flexible tooling systems were compared: a reusable silicone membrane and a traditional vacuum bag. Composite plates were manufactured with and without ultrasonic vibration for both systems. Fill time was observed, and post-cured samples were subjected to mechanical testing for flexural modulus, flexural strength, and interlaminar shear strength (ILSS). Void content …

Scaling Wind Farm Layout Optimisation To Meet Uk Energy Demands, Grace Richardson

The Plymouth Student Scientist

This research aims to explore the Wind Farm Layout Optimisation Problem (WFLOP) through both single- and multi-objective optimisation, to show that it can be used to create farm layouts that provide enough power for all homes in the UK. We highlight the intricacies of the problem, including the application of different algorithms and models, and the challenges of scaling the models to achieve optimal results. We employ both a Hill Climbing Algorithm (HCA) and an evolutionary algorithm (NSGA-II) to obtain wind farm layouts, and compare these to the well-known results proposed by Mosetti et al. Moreover, we present a novel …

Design And Validation Of An Industrial Out-Of-Plane Permeability Test Rig Of Fibre Preforms For The Development Of Next Generation Aircraft Structures, Callum Park

The Plymouth Student Scientist

Despite composites comprising 50% of modern aircraft structures, the absence of a standardised method for measuring out-of-plane permeability frequently results in manufacturing defects in early-development aerospace components, directly impacting safety, manufacturing efficiency and costs. This study aimed to address this gap, by designing and commissioning a compact, vacuum-assisted, mass flow test rig, capable of evaluating the saturated out-of-plane permeability of a variety of materials. This design incorporated learnings from theory, previous studies and discussions with industry experts. E-glass, a Metyx unidirectional carbon and the Teijin ITS55 carbon were investigated, where E-glass exhibited the highest permeability of 1.88E-12m², while …