Digital Commons Network^™

An Investigation Into The Impact Of Inverter Based Resources On Critical Clearing Time, Trupal Patel

All Dissertations

Renewable energy sources, mainly inverter-based resources (IBRs) such as solar and wind plants are being connected in large numbers to the bulk power grid in the United States and around the world. Additionally, generation using fossil fuels are being phased out, which results in the loss of rotor inertia, a key contributor to the transient stability of power systems. Therefore, the large-signal behavior of IBRs and its impact on transient stability must be studied.

This work studies this impact through the metric of critical clearing time (CCT). Impact of grid topology, generation mix and control modes of IBRs on CCT …

Bilevel Network Interdiction Models For Human Trafficking Disruption, Daniel Bruno Lopes Da Silva

All Dissertations

In this dissertation, we study a series of bilevel network interdiction problems motivated by applications in human trafficking disruption. First, we consider a bilevel network interdiction problem where the follower aims to maximize the amount of flow from the source node to the sink node and the leader aims to minimize the number of arcs from a critical set that have positive flow on them in the solution obtained by the follower. This problem models the situation where an anti-trafficking agent wants to minimize the number of people affected by the trafficking operations whereas the trafficker wants to maximize trafficking …

Modeling Disaster Resilience Through A Human-Centered Lens: Exposure, Vulnerability And Adaptation, Tong Liu

All Dissertations

The core of reframing and operationalizing disaster resilience with a human-centered lens is to incorporate concepts from socio-ecological resilience into engineering resilience to better understand the humans’ capability for disaster adaptation. Existing studies have drawn practical implications by identifying actionable thresholds for infrastructure systems under disasters, which can be easily applied by policymakers, emergency managers and municipal agencies. However, how individuals interact with, respond to, or adapt under these infrastructure thresholds remain understudied. This hinders the operationalization of disaster resilience at the human scale.

First, I examined exposure by analyzing how configuration and distribution of urban infrastructure systems, such as …

Synthesis And Characterization Of Magnetic Nanoparticles To Study Effective Magnetic Anisotropy For Biomedical And Catalytic Applications, Alexander Malaj

All Dissertations

This dissertation focuses on understanding how to tune the magnetic properties of nanoparticles through controlling the effective magnetic anisotropy (Keff), which is a key variable in determining a nanoparticle’s Néel relaxation time, which will dictate its magnetic behavior in various applications. In this work, magnetocrystalline anisotropy is tuned by synthesizing tri-metallic substituted ferrite (Fe3-x-yMnxCoyO4) nanoparticles with specific metallic compositions that were informed by computer simulations using density functional theory (DFT) to target magnetocrystalline anisotropy values. A drip synthesis was used to control the size and composition of the tri-metallic ferrites, which were revealed to be monodisperse and compositionally mixed by …

Constructing A State: Canals And The Transformation Of The Economy, Politics, And Finance In Nineteenth-Century New York, Youwei Xing

All Dissertations

This dissertation consists of three essays in economic history, unified by a focus on one of America's earliest transportation infrastructures, the canal system, in nineteenth-century New York. Each chapter explores a different aspect of the state's transformation: its economy, politics, and finance, each of which helped construct New York as the Empire State.

The first chapter studies the economic impact of canals on economic modernization from three aspects: sectoral transition, urbanization, and banking development. Contrary to much of the modern literature finds transportation infrastructure leads to decentralization, I find the opposite-evidence of centralization. Specially: (1) canal towns experienced a transition …

Fleet Algorithm Design For Pooled Rideshare: Integrating Human Factors, Simulation, And Optimization, Joseph Paul

All Dissertations

This dissertation explores the study the integration of human factors modeling and rideshare fleet control algorithms. Pooled rideshare is a unique transportation mode offering that allows riders increased flexibility and accessibility over public transportation, and decreased cost relative to personal vehicles or traditional rideshare. Additionally, relative to personal vehicles, pooled rideshare offers reduced costs and options for those with difficulty obtaining transportation. Prior research in the space typically focused on modeling human behavior, or optimizing system performance, but a lack of integration of the concepts leads to unrealistic or underutilized outcomes. To tackle this problem, novel rideshare assignment, and repositioning …

Design And Testing Method For Quality Control Of Chill Haze In Bourbon Production., Molly J. Wilburn

Electronic Theses and Dissertations

Chill haze is a quality issue in which white wisps and haze become visible in spirits when reaching sub 0℃ temperatures. Common quality control test methods rely on subjective visual tests and ambient temperature turbidity measurements. Currently there is limited access to commercial devices capable of reaching the sub 0 ℃ temperatures that are required for the formation of chill haze. This thesis focuses on the design, assembly and calibration of a custom-built turbidity meter capable of sub 0 ℃ temperatures and humidity control. The system uses an optical sensor at 90 ° to a light source to detect light …

Material Extrusion 3d Printing Of Metal Alloy: Material, Methods And Application., Sihan Zhang

Electronic Theses and Dissertations

Material extrusion (MEX) additive manufacturing presents a promising pathway for producing metal components with complex geometries while avoiding the safety hazards associated with loose powder handling in conventional metal additive manufacturing processes. This dissertation investigates the development and optimization of MEX processes for aluminum alloys, addressing critical challenges in feedstock formulation, printing parameter optimization, and post-processing strategies. Three distinct approaches were explored to advance the capabilities of aluminum MEX: filament-based processing of 6061 aluminum, paste-based extrusion of 6061 aluminum, and development of a novel aluminum-magnesium-tin alloy system for space manufacturing applications. The filament-based approach successfully demonstrated the production of 6061 …

Influence Of Mixing Duration And Absorption Characteristics Of Superabsorbent Polymers On The Fresh And Hardened Properties Of High-Performance Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the combined influence of superabsorbent polymers (SAPs) with distinct absorption kinetics and extended mixing sequences on the rheological, mechanical, and transport properties of high-performance concrete (HPC). Two SAPs—an ionic acrylamide-co-acrylic acid copolymer (SAP-P) and a non-ionic acrylamide polymer (SAP-B)—were incorporated at an internal curing level of 100%. The impact of extended mixing times (3, 5, and 7 min) following SAP addition was systematically evaluated. Results showed that longer mixing durations led to increased superplasticizer demand and higher plastic viscosity due to continued water absorption by SAPs. However, yield stress remained relatively stable owing to the dispersing effect …

A Methodology For Model-Based Certification, Jay Albert Silverman

Engineering Management & Systems Engineering Theses & Dissertations

A need for a single source of knowledge for design decisions has led to the development of a new field of systems engineering, model-based systems engineering (MBSE) (Delligati, 2014). System certification is defined as affirming that regulatory requirements for a system have been met (Goodwin & Juzaitis, 2006). System certification is a specific application of system validation. System verification can be defined as ensuring that the system of interest (SOI), as designed, is in accordance with the design inputs/requirements. System validation can be defined as ensuring that the SOI, as designed, meets the defined system needs (Wolfgand, Katz, & Wheatcraft, …

Input Structure Based Optimization For Privacy Preserving Ai Systems, Feng Yizhou

Electrical & Computer Engineering Theses & Dissertations

As Artificial Intelligence (AI) systems become increasingly integrated into critical domains, ensuring privacy-preserving model design and system deployment has become a pressing priority. Safeguarding both sensitive user data and proprietary model parameters is critical throughout the AI model and system, from data acquisition and pre-processing to model inference and deployment. However, existing privacy-preserving frameworks face several limitations, including fragmented data ownership, incomplete protection across system stages, substantial computational overhead, and poor scalability to modern architectures such as large language models. This dissertation explores a unifying optimization strategy centered on input structure design to address these challenges. The core idea is …

Human Activity Recognition And Identification Driven Automated Deep Learning For Time-Series Classification, Justin Alan Gamble

Engineering Management & Systems Engineering Theses & Dissertations

The growing emphasis on Digital Engineering (DE) within the U.S. Department of Defense (DoD) demands advanced methods for leveraging vast time-series data generated by sensor-rich environments. Deep learning models offer promising solutions for complex timeseries classification tasks, however their design and optimization remain highly resource intensive, requiring specialized expertise. This dissertation addresses this challenge by developing and evaluating an Automated Machine Learning (AutoML) framework specifically tailored for the time-series classification task of Human Activity Recognition and Identification (HARI).

A systematic investigation was conducted using the Design Science Research Methodology (DSRM) comparing traditional search strategies of grid search and random search …

Mantle Flow And Crustal Deformation Revealed By Seismic Anisotropy In The Subduction Zone Beneath Myanmar, Enbo Fan, Mingming Jiang, Yinshuang Ai, Stephen S. Gao, Kelly H. Liu, Yumei He, Yiming Bai, Guangbing Hou, Yuan Ling, Chit Thet Mon, Myo Thant, Kyaing Sein

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The oblique convergence of the Indian and Eurasian plates drives significant deformation in the crust and mantle beneath Myanmar. However, the crustal deformation in the Indo-Burman Ranges (IBR) and mantle flow beneath Myanmar and adjacent areas remain unclear due to limited studies. We utilized data from the newly deployed second phase of the China-Myanmar Geophysical Survey of the Myanmar Orogen array to perform shear wave splitting analysis of PKS, SKKS, and SKS (XKS) phases. Our results, together with previous findings, provide new insights into mantle flow and crustal deformation across central Myanmar. In the IBR, we observed a transition from …

Microstructural Investigation Of Graphene Reinforced Nickel Aluminum Bronze Prepared Via Laser Powder Bed Fusion, Wen Qian, Maxwyll Mcconnell, Jazmin Ley, Luke Schwaninger, Xin Chen, Bai Cui, Joseph A. Turner

Mechanical Engineering Faculty Publications

Nickel aluminum bronze (NAB) powders coated with reduced graphene oxide (RGO) were successfully fabricated using additive manufacturing (AM) via laser powder bed fusion. The resulting samples were characterized using a suite of complementary techniques, including x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, nanoindentation, x-ray computed tomography, and electron backscatter diffraction. These methods were employed to reveal the micro- and nanoscale features within the fine dendritic microstructure. The as-fabricated microstructures were observed to deviate significantly from typical as-cast configurations. In the AM RGO-coated NAB specimens, the formation of the κ_I phase was notably suppressed and is attributed to the …

Enhancing Microgrid Protection Through Adaptive Decentralized Relay Coordination: A Solution To Blinding And Sympathetic Tripping, Sujatha Balasubramanian, J. Preetha Roselyn, Prabha Sundaravadivel

Electrical Engineering Faculty Publications and Presentations

Integrating Distributed Energy Resources into microgrids modifies the network’s system parameters and causes it to exhibit behaviour, particularly during fault conditions. This is due to the greater variations in current direction and magnitude. When a microgrid runs in autonomous mode, Distributed Generators result in a reduced short circuit current compared to a system working in grid-connected mode. Microgrid protection issues, namely, blinding of protection, sympathetic tripping, and bidirectional power flow, occur in the power network under such circumstances. The impact of microgrid protection issues and changes in fault current leads to variations of overcurrent relay settings, their operating time and …

From Waste To Solution: Modeling And Characterization Of Grape Seed Bio-Waste For Phosphate Removal From Wastewater, Abeer Al-Bsoul, Zakaria Al-Qodah, Muhammad Tawalbeh, Khalid Bani-Melhem, Khalideh Al Bkoor Alrawashdeh, Mohammad Hailat, Ahmed A. Al-Taani, Eid Gul

All Works

In this study, particles of ground grape seeds were utilized to adsorb phosphate ions from a prepared solution, aiming to reduce phosphate concentration. Through a series of adsorption experiments, the effects of the adsorbent concentration, initial phosphate ion concentration, temperature, and pH on the phosphate ion uptake were studied. The removal efficiency of the phosphate ion decreased from 77 to 61% as a 25 to 45 °C increment in temperature was observed, which indicated the exothermicity in the adsorption process. The phosphate ion movement onto the adsorbent surface that exhibited the highest uptake value favored a neutral reaction environment with …

Validation Of A Methodology For Predicting Yield Acceleration Of Rock Blocks, Madison Haydn-Myer

Graduate Theses & Non-Theses

Rock slope stability is a critical concern in seismically active regions, where earthquakes can trigger sudden and hazardous failures. Predicting these failures is challenging due to the complex interactions between seismic loading and geological characteristics. This study proposes a simplified analytical model to predict yield acceleration based on the forces acting upon a block just before sliding initiates. A key parameter in this equation is the friction acting on the bottom surface of the block. As rock blocks are commonly formed by the intersection of sets of subparallel fractures known as joints, and the roughness and other features of those …

Genwriter: Reducing Gender Cues In Biographies Through Text Rewriting, Shweta Soundararajan, Sarah Jane Delany

Conference papers

Gendered language is the use of words that indicate an individual’s gender. Though useful in certain context, it can reinforce gender stereotypes and introduce bias, particularly in machine learning models used for tasks like occupation classification. When textual content such as biographies contains gender cues, it can influence model predictions, leading to unfair outcomes such as reduced hiring opportunities for women. To address this issue, we propose GenWriter, an approach that integrates Case-Based Reasoning (CBR) with Large Language Models (LLMs) to rewrite biographies in a way that obfuscates gender while preserving semantic content. We evaluate GenWriter by measuring gender bias …

Modification Of Tini Alloy By Fast Pulse Laser Heat Treatment, Yitao Chen, Mohammad Masud Parvez, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, the effects of local heat treatment with fast pulse laser on thin TiNi shape memory alloy strip materials were investigated. Various materials characterization methods including optical microscope, scanning electron microscope, atomic force microscope, X-ray diffraction, differential scanning calorimetry, and Vickers hardness were used to identify the differences of microstructure, mechanical properties, and functional properties between regions inside and outside the laser-scanned region. The tensile test was also conducted for both the non-laser-scanned specimen and the laser-scanned specimen. The area covered by laser scanning shows great differences by possessing a more homogeneous austenite phase without shear bands and …

Digital Twins, Ai, And Cybersecurity In Additive Manufacturing: A Comprehensive Review Of Current Trends And Challenges, Md Sazol Ahmmed, Laraib Khan, Muhammad Arif Mahmood, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The development of Industry 4.0 has accelerated the adoption of sophisticated technologies, including Digital Twins (DTs), Artificial Intelligence (AI), and cybersecurity, within Additive Manufacturing (AM). Enabling real-time monitoring, process optimization, predictive maintenance, and secure data management can redefine conventional manufacturing paradigms. Although their individual importance is increasing, a consistent understanding of how these technologies interact and collectively improve AM procedures is lacking. Focusing on the integration of digital twins (DTs), modular AI, and cybersecurity in AM, this review presents a comprehensive analysis of over 137 research publications from Scopus, Web of Science, Google Scholar, and ResearchGate. The publications are categorized …

Examining Shock Wave Flow Past The Brim Of A Helmet Using Schlieren Imaging, Cody Thomas, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Increasing the protection a helmet provides the user from shock waves can help reduce the prevalence of blast induced traumatic brain injury (bTBI). Previous research has shown that air enters and gets trapped in the helmet-head cavity and can increase the overpressure experienced by the wearer. The brim design of the helmet has yet to be studied to understand how shock waves flow into the helmet. By studying a variety of brims, it is possible that the design can be modified to minimize shock wave flow into the helmet. This paper investigated a shock wave impacting interior and exterior facing …

Predicting Miner Localization In Underground Mine Emergencies Using A Hybrid Cnn-Lstm Model With Data From Delay-Tolerant Network Databases, Patrick Nonguin, Samuel Frimpong, Sanjay Madria

Mining Engineering Faculty Research & Creative Works

Underground mining environments are highly hazardous, often prone to gas explosions, cave-ins, and fires that may trap miners during emergencies. The accurate, real-time localization of miners is vital for effective self-escape and rescue operations. Although the Mine Improvement and New Emergency Response (MINER) Act of 2006 mandates communication and tracking systems, most current solutions rely on low-power devices and line-of-sight methods that are ineffective in GPS-denied, dynamic subsurface conditions. Delay-Tolerant Networking (DTN) has emerged as a promising alternative by supporting message relay through intermittent links. In this work, we propose a deep learning framework that combines Convolutional Neural Networks (CNNs) …

Ai-Driven Uncertainty Quantification & Multi-Physics Approach To Evaluate Cladding Materials In A Microreactor, Alexander Foutch, Kazuma Kobayashi, Ayodeji Babatunde Alajo, Dinesh Kumar, Syed Bahauddin Alam

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The pursuit of enhanced nuclear safety has spurred the development of accident-tolerant cladding (ATC) materials for light water reactors (LWRs). This study investigates the potential of repurposing these ATCs in advanced reactor designs, aiming to expedite material development and reduce costs. The research employs a multi-physics approach, encompassing neutronics, heat transfer, thermodynamics, and structural mechanics, to evaluate four candidate materials (Haynes 230, Zircaloy-4, FeCrAl, and SiC–SiC) within the context of a high-temperature, sodium-cooled microreactor, exemplified by the Kilopower design. While neutronic simulations revealed negligible power profile variations among the materials, finite element analyses highlighted the superior thermal stability of SiC–SiC …

Effect Of Moderate Decrease In Contractility On Epithelial Cell-Cell Contacts Under External Stretch, Saika Sharmin

Mechanical & Aerospace Engineering Theses & Dissertations

Epithelial tissues are characterized by extensive cell–cell contacts and often subject to stretch during normal function. Cell-cell contact adhesion strength maintains mechanical continuity from cell to cell. Mechanical forces exerted by cells via actomyosin contractility are known to strengthen cell-cell adhesions to a certain extent. While it is known that a large decrease in contractility causes cell-cell contact rupture due to weakened adhesions, it is unclear how a moderate reduction in contractility affects cell-cell junction stability. Here, we studied how a moderate inhibition of non-muscle myosin II (NMII) affects the integrity of epithelial cell-cell contacts, especially when subject to the …

A Three-Stage Matheuristic For The Blood Stochastic Inventory Routing Problem, Vincent F. Yu, Nabila Salsabila, Aldy Gunawan, Aldy Gunawan, Nurhadi Siswanto

Research Collection School Of Computing and Information Systems

This research introduces a blood distribution system under vendor-managed inventory that considers uncertain supply and demand. We present it as the Blood Stochastic Inventory Routing Problem, formulating it as a two-stage stochastic programming model. To solve this problem, this study proposes a three-stage matheuristic that combines a perturbation heuristic, Adaptive Large Neighborhood Search, and an exact approach. From historical data of Surabaya Blood Center in Indonesia, six sets of new instances are generated under different settings. Computational results show that our proposed three-stage matheuristic outperforms CPLEX and a two-stage matheuristic by gaining optimal or better solutions within a significantly shorter …

Supporting Programmers Answering The Hard-To-Answer Questions Through The Use Of Large Language Models, Haixin Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Programmers often face hard-to-answer questions when working on large-scale projects. Not only during team collaborations, but also during interruptions such as meetings, having to suddenly work on another project, or even just taking a break are major reasons these questions arise, as programmers have to regain the context, knowledge, and mental state to resume the work. Traditional text editors such as GitHub do provide a built-in history system, but they lack historical context behind the editing to answer such questions.

To address this issue, we developed an experimental extension, Code History, on Visual Studio Code (VS Code) in the hope …

Evaluating The Impact Of Activated Carbon On The Biodegradation Of Btex Compounds, Megan Barkley

All Theses

BTEX compounds—benzene, toluene, ethylbenzene and xylenes—are toxic, volatile, aromatic hydrocarbons. They are primarily found in petroleum products and can easily enter the environment. Typical remediation techniques include sorption to activated carbon, pump and treat, and bioremediation. Research suggests that combining sorption to activated carbon and bioremediation may enhance BTEX removal. This study evaluates the impact of granular activated carbon (GAC) on the biodegradation of ethylbenzene and toluene, using an enrichment culture of aerobic bacteria.

The main objectives of this study are to grow and maintain a culture that degrades BTEX compounds, evaluate the effect of activated carbon on the biodegradation …

Mechanoregulation Of Osteogenesis And Adipogenesis Of Human Mesenchymal Stem Cells, Justin Caron

Master's Theses

Bone-related diseases (e.g., osteoporosis) are primarily treated with pharmacologic therapies that often exhibit limited efficacy and substantial side effects. Currently, bone marrow derived mesenchymal stem cells (MSCs) have become one of most important cell options in bone regeneration due to readily available sources, strong proliferation abilities, weak immune rejection responses, and strong osteogenic differentiation potential. While identifying the most effective approach to enhance osteogenic differentiation of MSCs for bone regeneration is challenging, understanding the regulatory mechanisms is crucial for improving therapeutic efficacy. Recent research has focused on developing strategies to enhance osteogenesis, which involve biophysical and biochemical stimulation. Mechanical and …

Valorizing Cement Kiln Dust And Glass Powder: A Binder Study On Sustainable Partial Cement Replacement, Sai Kiran Simhadri

Civil & Environmental Engineering Theses & Dissertations

The production of cement ranks as a major source of global CO₂ emissions because of the high energy requirements needed to create clinker. The construction industry is actively seeking ways to reduce its carbon footprint. Utilizing industrial waste materials to partially replace cement can lower emissions. This research evaluates a ternary binder system which uses Cement Kiln Dust (CKD) and Glass Powder (GP) to replace a portion of Type IL (Portland Limestone) cement. The mixes were made with a fixed water-to-binder ratio of 0.44 and contained 15% GP by mass while the CKD content ranged from 0% to 10%. The …

A Strict Physicality-Preserving Scheme For A 2d Q-Tensor Flow With A Singular Potential, Md Mashud Parvez

Mathematics & Statistics Theses & Dissertations

Nematic liquid crystals are a state of matter that exhibit properties between those of conventional liquids and solid crystals. Their unique ability to align molecules in specific directions makes them essential in various applications, including display technologies and advanced materials. To model their complex behavior, mathematical frameworks such as the Q-tensor model are used to describe the orientation and degree of molecular order. In this work, we introduce a numerical scheme for a two-dimensional (2D) dynamic Q-tensor model, which is formulated as an L²-gradient flow driven by the liquid crystal free energy and incorporates a singular potential to …