Digital Commons Network^™

Overcoming Resolution Vs. Throughput Trade-Offs In Ceramic Material Extrusion Additive Manufacturing Via Viscoelastic Filament Stretching, Abid H. Rafi, David W. Lipke, Jeremy L. Watts, Gregory E. Hilmas, Ming C. Leu

Materials Science and Engineering Faculty Research & Creative Works

Fabricating large, monolithic ceramic parts using material-extrusion additive manufacturing remains challenging due to difficulty maintaining uniform moisture content during printing, which can lead to drying-induced defects such as warping and cracking, especially as part size and print time increase. Fabricated parts have trade-offs among print resolution, high throughput, and structural fidelity. Our study has shown that increasing the ratio of nozzle traverse speed vs. material extrusion speed increases filament stretching in viscoelastic ceramic paste, helping to overcome the trade-offs between resolution and throughput. Using aqueous ZrB2–SiC (70/30 vol.%) as a representative ultra-high temperature ceramic paste, rheological characterisation revealed viscoelastic yield-stress …

Generative Imaging For Computational Pathology, Md Jillur Rahman Saurav

Computer Science and Engineering Dissertations

Hematoxylin and eosin (H&E) staining remains central to cancer diagnosis, providing morphological information essential for pathological assessment. Immunohistochemistry (IHC) and newer multiplexed imaging technologies complement H&E by revealing molecular information critical for accurate tumor subtyping and treatment decisions. In practice, however, H&E and IHC are obtained from different consecutive sections that are not spatially aligned, comprehensive multiplexed panels are expensive and tissue-consumptive, and not all stains are available at every clinical site, limiting comprehensive molecular profiling and the full diagnostic potential of these technologies in clinical practice. This dissertation addresses these gaps through three complementary generative deep learning studies in …

Exploring Relational Farming Futures For Responsible Innovation In Precision Agriculture Through Q-Method And Speculative Design, Bhavna Joshi, Maaz Gardezi, Edward Prutzer, Awais Hameed Khan, Asim Zia, Benjamin E. K. Ryan, Ali Dadkhah, Donna M. Rizzo, John T. Mcmaine, David Clay

Biosystems and Agricultural Engineering Faculty Publications

This article draws on concepts of speculative design and responsible innovation to examine the possible impacts of data-driven precision agriculture on farmers and farm work. We use an innovative mixed-method approach to research design. Using artistic depiction of futures of precision agriculture in design workshop and in-depth semistructured interviews conducted with the farmers in Vermont and South Dakota, we explain how farmers perceive different futures of precision agriculture. Specifically, in our design workshop, we combined visual arts and social science methods, namely Q-method, to explore existing and new relationships between humans, technologies, and environment in the design, deployment, and use …

Validity And Reliability Of Force Insoles To Measure Center Of Pressure During Return-To-Sport Testing, Delaney Mcneese, Charles Eisner, Rachel Todd, Brian W. Noehren, Meredith K. Owen

Biomedical Engineering Faculty Publications

Center of pressure is a valuable biomechanical variable, predicting joint loading contributions during movement and giving insight into compensatory patterns. The purpose of this study was to assess the validity and reliability of force insoles in calculating vertical ground reaction force and center of pressure during return-to-sport jump testing. Ten healthy individuals performed double- and single-leg vertical and horizontal jumps on an instrumented treadmill while wearing instrumented force insoles. Vertical ground reaction force and anterior–posterior and medial–lateral center of pressure were collected at peak vertical ground reaction force from both devices. Repeat testing occurred 7 ± 5 days following the …

Non-Contact Optical Spectroscopy For Metabolic And Vascular Characterizations Of Orthotopic Tongue Cancer Models In Vivo, Md Zahid Hasan, Jing Yan, Sumit Sarker, Pranto Soumik Saha, Caigang Zhu

Biomedical Engineering Faculty Publications

Most tissue optical spectroscopy platforms use a fiber probe for light delivery and collection, while the inconsistent probe-sample contact could induce significant distortions in the measured optical signals, which consequently bring analysis errors. Moreover, it will be practically difficult to use a fiber probe for measurements in some cases such as oral cancer investigations using small animal models. To address the critical challenge, we report a portable, lens-based, optical spectroscopy device capable of quantifying key vascular and metabolic parameters in vivo without probe-sample contact. We combined lenses based diffuse reflectance and fluorescence spectroscopy into one portable platform to enable multi-parametric …

Noninvasive Diffuse Optical Monitoring Of Cerebral Blood Flow And Oxygenation Responses To Intermittent Hypoxia In Neonatal Rats, Pegah Safavi, Mehrana Mohtasebi, Chowdhury Azimul Haque, Faezeh Akbari, Xuhui Liu, Yiqi Yuan, Li Chen, Lei Chen, Guoqiang Yu

Biomedical Engineering Faculty Publications

Significance: Intermittent hypoxia (IH) is common in preterm neonates and can cause hypoxic–ischemic brain injury. Simultaneous monitoring of cerebral blood flow (CBF) and oxygenation is essential to detect oxygen delivery-extraction mismatches and guide intervention.

Aim: We aimed to adapt and test an innovative diffuse speckle contrast flow oximetry (DSCFO) system for continuous monitoring of cerebral hemodynamics during IH in neonatal rats, a model approximating human neonates.

Approach: Two compact laser diodes and a miniature CMOS camera were integrated into a fiber-free probe for continuous monitoring of changes in relative CBF (rCBF) and oxy- and deoxy-hemoglobin concentrations (Δ[HbO₂] and …

Simulation And Characterization Of Fuel Cell System Incorporated Internet Of Things, Ahmad N. Alhjouj

Mechanical Engineering Theses

Small air-cooled proton exchange membrane fuel cell (PEMFC) systems are increasingly relevant for portable and distributed applications, yet practical modeling and monitoring methods remain limited: high-fidelity physics-based models are too costly for real-time use, while purely data-driven models discard physical interpretability. This thesis develops an experimentally grounded gray-box framework for the characterization, reduced-order modeling, and IoT-enabled monitoring of a small hydrogen PEMFC system. A low-order nonlinear state-space model couples an electrochemical voltage layer to a lumped thermal layer, with parameters identified in stages using self-adaptive differential evolution. Identifiability analysis shows that static loss parameters are well constrained, while dynamic parameters …

Early Detection And Objective Assessment Of Neonatal Hypoxic-Ischemic Encephalopathy Severity, Soheila Norasteh

Bioengineering Dissertations

Hypoxic–ischemic encephalopathy (HIE) is a neonatal brain injury caused by reduced oxygen and blood flow to the brain around the time of birth. It remains a major cause of neonatal mortality and long-term neurodevelopmental impairment worldwide. Therapeutic hypothermia is the standard treatment for moderate-to severe HIE and improves outcomes when initiated within the first six hours of life. Therefore, accurate assessment of injury severity during this period is essential. Cur rently, HIE severity is determined primarily through neurological examination and classified as mild, moderate, or severe. However, these examinations are subjective, cannot provide continuous monitoring of brain function, and may …

Proactive Safety Reasoning In Human-Robot Collaboration In Disassembly Through Llm-Augmented Stpa And Fmea, Morteza Jalali Alenjareghi, Fardin Ghorbani, Samira Keivanpour, Yuvin Adnarain Chinniah, Sabrina Jocelyn

Études primaires

Disassembly tasks in human–robot collaboration (HRC) environments present safety challenges due to hazardous materials, control system variability, and physically demanding operator tasks. To address these challenges, we propose an AI-augmented risk assessment framework integrating System-Theoretic Process Analysis (STPA) and Failure Mode and Effects Analysis (FMEA). This framework is implemented in four configurations: Term Frequency– Inverse Document Frequency (TF-IDF), Fine-tuned Large Language Models (LLMs), Retrieval-Augmented Generation (RAG), and RAG with a structured Knowledge Graph (KG) built from safety standards. The system supports real-time, standards-compliant safety reasoning by generating interpretable, context-specific recommendations. We evaluate these configurations across GPT-3.5 TURBO, GPT-4o, GPT-4.1, and …

Electron Beam Irradiation Effects On Bulk Metals: A Comparative Study Of Polycrystalline Versus Single-Crystalline Structures, A. A. Elmustafa, N. A. Sultana, A. H. Al-Allaq, M. Ojha, Y. S. Mohammed, J. Vennekate, H. Baumgart

Mechanical & Aerospace Engineering Faculty Publications

This study investigates the effects of electron beam (e-beam) irradiation on the mechanical and structural properties of eight bulk metallic samples, comprising both polycrystalline (PC) and single-crystalline (SC) forms of Ni, Cr, V, and Ti. These metals were evaluated as potential candidates for beam exit windows in high-power (MW-class) particle accelerators. The primary objective is to identify metals capable of withstanding the conditions of high-power/MW-class e-beam accelerators and serve effectively as exit windows. Selection criteria were based on each metal’s intrinsic properties, power dissipation capability, and irradiation-induced changes in mechanical behavior, including hardness, elastic modulus, and defect density. Comprehensive characterization …

A Four-Step Thermocatalytic Route For Converting Co2 Into High-Purity Oxalic Acid, Hao Feng, Muhammad Kashif Khan, Lei Li, Hongyan Ma, Xinhua Liang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This research outlines a four-step methodology for transforming CO₂ into high-purity oxalic acid. CO2 was first sequestered as KHCO₃ through its reaction with aqueous KOH, followed by hydrogenation using a supported AgPd/CNT catalyst in a batch reactor at an initial H₂ pressure of 60 bar and a temperature of 150°C. The formate yield reached 91.8% at optimum conditions. Potassium formate in the solid state was thermally coupled in the presence of KOH at 400°C under N2 flow, yielding potassium oxalate of up to 76% yield. The final step was the selective precipitation of potassium oxalate with ferrous …

Peculiarities Of Phosphatidylserine Externalization By Nano- And Microsecond Electric Pulses, Mantas Silkunas, Alayna Enos, Iurii Semenov, Giedre Silkuniene, Eleni Zivla, Olga N. Pakhomova, Andrei G. Pakhomov

Bioelectrics Publications

Phosphatidylserine (PS) externalization is a hallmark of apoptosis but can also be triggered within seconds by pulsed electric fields (PEFs). Whether PS reaches the outer leaflet by lateral migration through electropores or indirectly through Ca²⁺-dependent signaling and scramblase activation remains debated. We used total internal reflection fluorescence (TIRF) microscopy with Annexin V-Alexa Fluor 568 and/or bovine lactadherin-FITC to resolve PS externalization in HEK293 cells placed on an indium tin oxide (ITO) transparent electrode. PEF exposures produced discrete PS-positive puncta ("freckles") within ~ 10 s after a 20-µs pulse (1.2-2.5 kV/cm) or with a ~ 1-min delay after a …

An Investigation Of Quiet Bunks For Improved Rest On Marine Vessels, Jacob Milman

Open Access Master's Theses

Those who spend an extended period of time living in a marine setting (e.g. living and working on a research/commercial vessel) are subject to a variety of annoying/disturbing noises during periods of sleep. Numerous past studies (Kim et al., 2024; Sunde et al., 2016; Li et al., 2024) have linked noise exposure levels and poor sleep to health and safety risks, both in personal and professional settings. Thus, it is necessary to take a closer look at the typical levels of noise exposure which mariners aboard a research vessel are subjected to, as well as any factors relating to personal …

Noninvasive Optical Assessment Of Tissue Hemodynamics In Preterm Infants And Mastectomy Skin Flaps, Samaneh Rabienia Haratbar

Theses and Dissertations--Biomedical Engineering

Adequate tissue blood flow and oxygenation are essential for maintaining cellular viability and normal organ function. Disruptions in microvascular perfusion and oxygen delivery contribute to ischemia- and hypoxia-related diseases, including stroke, cancer, retinopathy of prematurity (ROP), and mastectomy skin flap necrosis. Reliable, noninvasive approaches for assessing tissue hemodynamics are therefore critical for improving diagnosis and therapeutic decision-making, particularly in settings where conventional methods are limited. This dissertation investigates the clinical and physiological importance of measuring tissue blood flow and oxygenation across neonatal and surgical applications using both clinical monitoring and advanced optical imaging techniques. In the first study, high-speed pulse …

Evaluating Training Effectiveness And Learning Transfer In The Kentucky Transportation Cabinet Safety Academy, Amanda L. Casolare

Theses and Dissertations--Civil Engineering

Effective evaluation of safety training is crucial to ensure that learning translates into safe work practices, particularly in high-risk public sector environments. The Kentucky Transportation Cabinet (KYTC) is developing a Safety Academy to enhance hazard recognition, risk management, and safety leadership within the organization. However, the Safety Academy has not yet been implemented, and formal evaluation methods for training have not been established. This study aimed to examine evidence-based training evaluation techniques and develop recommendations for evaluating the KYTC Safety Academy prior to program implementation.

This study employed an applied pre-implementation research design grounded in a comprehensive review of safety …

Mental Health And Help-Seeking In Engineering Education: Beliefs, Norms, And Intervention Pathways For Undergraduate Students, Matthew D. Whitwer

Theses and Dissertations--Chemical and Materials Engineering

Engineering education is at a critical juncture where supporting student mental health is essential for fostering persistence, equity, and the development of a resilient and innovative workforce. While engineering students experience high levels of distress and low rates of mental health treatment seeking (known as a mental health treatment gap), there is a gap in knowledge around how this compares to that of students in other fields of study. Further, while efforts have been made to improve the mental health treatment gap in engineering, they are limited by a lack of actionable, theory-based targets. Therefore, this dissertation aims to characterize …

A Specification-Driven Framework For Self-Supervised Learning In Specialized Vision Domains, Mahmut S. Gokmen

Theses and Dissertations--Computer Science

Self-supervised learning (SSL) has emerged as a principled approach to visual representation learning that derives supervisory signal directly from unlabeled data, enabling foundation models to be trained at scale without manual annotation. Deployments in medical imaging and biometric recognition have demonstrated the potential of this paradigm, yet the assumptions that make SSL effective on natural image benchmarks fail systematically in specialized domains. Generic SSL pipelines encode a tacit assumption that the most informative correspondence is spatial proximity within a single acquisition. In specialized domains this assumption breaks at the level of the data-generating process: the signal that carries domain-specific information …

Linking S‑Pillar Empirical Criteria With Boundary And Finite Element Models For Underground Stone Pillar Analysis, Benjamin Diddle

Theses and Dissertations--Mining Engineering

The objective of this thesis is to strengthen the relationship between empirically based stone pillar design methods and two numerical modeling techniques by calibrating boundary element and finite element models to the S‑Pillar empirical criteria and observed pillar behavior in underground stone mines. The first component of the research investigates the displacement‑discontinuity boundary element method implemented in LaModel, quantifying the influence of the lamination thickness and element size on stone pillar safety factor predictions. Results showed that optimal thickness depends on overburden modulus, while larger element sizes introduce significant SF differences from S-Pillar values once the grid size exceeds 5 …

From Floodplain To Floodplain: Analyzing Stream And Riparian Restoration Methodologies And Impacts, Noah P. Lane

Theses and Dissertations--Biosystems and Agricultural Engineering

Stream restoration is a relatively new scientific field. Currently, there is not a definitive methodology for performing restorations that all professionals in industry and academia can agree upon. This has allowed for multiple ideologies to be developed and altered that vary by geographic location and the professional using them. In addition to the methodologies used, the publicly available design guidance published by state government organizations also varies by regulatory authority, method of analysis, ecoregion, and restoration objectives. In some cases, design guidance is replicated from a different geographical area and may not satisfy local needs or existing site conditions. Since …

Multisystem Predictors Of Dynamic Gait Stability Across Fall Risk In Older Adults, Ashwini Kulkarni, Neda Moghim, Ross Gore, Soumya Banerjee, Christopher K. Rhea, Brittany Samulski

Rehabilitation Sciences Faculty Publications

Gait stability arises from interactions between physiological, cognitive, and psychological systems, yet these domains are often assessed in isolation. This study examined multisystem predictors of anteroposterior margin of stability during walking (MoSAP) in community-dwelling older adults. Of 340 participants, 143 were retained after data quality screening (105 females; age: 70.8 ± 7.8 years). Participants completed the Physiological Profile Assessment (PPA), cognitive testing using Montreal Cognitive Assessment (MoCA), fear-of-falling evaluations using Modified Falls Efficacy Scale (MFES) and a biomechanical gait assessment during preferred and fast speeds. Participants were stratified into four PPA-based fall-risk groups: low, mild, moderate, and high risk. MoSAP …

Social Safety And Social Security: Validating Context-Specific Instruments For Slums, Liss D. Romero, Katherine Palacio, Zacheous Ako Abang, Valeria Silgado, Humberto Llinas, Leidy González, Erika Frydenlund, Daniel Bolivar, Jose J. Padilla

VMASC Publications

Social safety and social security are concepts that help explain a community's well-being by assessing how it manages and mitigate existing, or perceived, risks. However, these terms are often conflated, which can limit understanding, particularly in areas with unstable living conditions. This study explores both concepts in the context of residents living in slums. As the number of displaced people grows, slums and informal settlements are becoming increasingly common worldwide, making it essential to clarify these concepts. Residents of slums face numerous hazards, including crime, violence, inadequate housing, overcrowding, and limited access to essential services. To measure social safety and …

Nanosecond Electric Pulses As A Novel In Situ Vaccination Strategy For Cancer Treatment: Mechanisms, Challenges And Prospects, Siqi Guo

Bioelectrics Publications

Nanosecond electric pulses (nsEPs) are an emerging pulsed-power technology with unique bioelectric characteristics distinct from conventional long-pulse electroporation. As a tunable physical modality, nsEPs can modulate intracellular structures, membrane dynamics, and signaling pathways. Increasing evidence supports nsEPs as a promising non-thermal tumor ablation approach due to their high spatial precision, preservation of critical tissue structures, and minimal adverse effects. One of the most significant discoveries associated with nsEP tumor ablation is the induction of potent systemic antitumor immunity, particularly in situ vaccination (ISV) effects and, in some cases, abscopal effects against distant untreated tumors. Substantial evidence demonstrates that nsEPs can …

An Intuitionistic Fuzzy Hypergraph Model Enhanced ‎By Forest-Of-Walks Dynamics For Medical Image ‎Segmentation, Brinthaguru Thangaraj, Karthick Palanisamy

Mansoura Engineering Journal

The process of accurately segmenting Urolithiasis and pulmonary nodules from medical images presents significant difficulties because of three main factors which include nonuniform intensity distribution and the presence of weak object borders and the uncertainty caused by anatomical structure overlaps. The study introduces F-Zinhger as a solution to these problems through its application of the Forest of Walks technology. The method uses superpixels as fundamental elements which form a multi-scale hypergraph that establishes hyperedges through three criteria: intensity similarity, spatial proximity, and Z-intuitionistic fuzzy hesitation to capture complex contextual connections. The system incorporates a random walk-based label propagation system. The …

Development Of A 3d-Printed Hemodynamic Model To Characterize Doppler Signatures Of Obstructed Tapvr, Michael R. Turner, Maher R. Saadeh, Holly D. Bauser-Heaton, Vahid Serpooshan

Summer Research Program Abstracts

No abstract provided.

Machine Learning For Predicting Prosthetic Limb Movements, Jessica Alexandra Cegarra Arraiz

Theses and Dissertations

This thesis develops and evaluates a deep learning-based prediction model capable of identifying intended limb movement from surfaced electromyography (sEMG) signals using sequence learning techniques. sEMG signals change over time due to multiple factors such as muscle fatigue or user variability. Traditional prosthetics control methods rely on static feature extraction, ignoring how signals change over time, thereby limiting their ability to capture the temporal changes of muscle activity. As a result, these approaches often lead to poor accuracy, robustness, and generalization. Limited experimental validation has been conducted on sequence-based machine learning approaches using temporal sEMG data from publicly available datasets …

Five Tensions Of Artificial Intelligence Adoption For Organ Allocation: Applying The Technology–Organization–Environment Framework, Amaneh Babaee, Daniel Burton Shank, Casey I. Canfield, Joely Grace Hall, Krista L. Lentine, Henry Randall, Mark Schnitzler

Psychological Science Faculty Research & Creative Works

Background: The US organ transplantation system is pursuing modernization of the allocation process through the integration of new technologies such as artificial intelligence (AI). However, the legal and ethical issues within the transplantation industry are still of concern. Objective: We explore the opportunities and challenges for Organ Procurement Organizations (OPOs) to adopt AI. The US organ transplant system is a highly regulated industry yet open to innovation. Methods: Ten structured interviews were conducted with OPO representatives using the Extended Technology, Organization, Environment (TOE) framework. Results: Overall, we identified five core tensions in AI adoption: (1) misconceptions, (2) approach to training, …

Evaluation Of Multiple Generative Large Language Models On Neurology Board-Style Questions, Mohammad Almomani, Vijaya Valaparla, James Weatherhead, Xiang Fang, Alok Dabi, Chih Ying Li, Peter Mccaffrey, Dan Hier, Jorge Mario Rodríguez-Fernández

Electrical and Computer Engineering Faculty Research & Creative Works

Objective: To compare the performance of eight large language models (LLMs) with neurology residents on board-style multiple-choice questions across seven subspecialties and two cognitive levels. Methods: In a cross-sectional benchmarking study, we evaluated Bard, Claude, Gemini v1, Gemini 2.5, ChatGPT-3.5, ChatGPT-4, ChatGPT-4o, and ChatGPT-5 using 107 text-only items spanning movement disorders, vascular neurology, neuroanatomy, neuroimmunology, epilepsy, neuromuscular disease, and neuro-infectious disease. Items were labeled as lower- or higher-order per Bloom's taxonomy by two neurologists. Models answered each item in a fresh session and reported confidence and Bloom classification. Residents completed the same set under exam-like conditions. Outcomes included overall and …

Advancing Cns Tumor Management: Novel Modalities In Surgery, Radiation, And Chemotherapy, Armin David Tavakkoli

Dartmouth College Ph.D Dissertations

Most tumors affecting the brain and spine are managed through a combination of surgical resection, radiation, and chemotherapy; however, operative morbidity from invasive surgery, the narrow therapeutic window of conventional radiotherapy, and poor blood-brain barrier penetration of systemic agents are critical barriers that hinder long term tumor control. This thesis presents three complementary strategies to advance brain and spine tumor therapy. First, we investigate laser interstitial thermal therapy (LITT) in the treatment of spinal tumors with metastatic epidural spinal cord compression, replacing “separation surgery” with a minimally invasive, image-guided approach that maximizes tumor ablation while preserving neurologic function. Second, we …

Process Modeling, Operability Analysis, And Techno-Economic Optimization Of Soecs For Sustainable H2 Production, Krishna Murthy Busam

Graduate Theses, Dissertations, and Problem Reports (ETD)

The global imperative to decarbonize energy systems has intensified research into sustainable hydrogen production pathways, as hydrogen emerges as a critical energy carrier for sectors difficult to electrify directly. Among water electrolysis technologies, solid oxide electrolyzer cells operating at elevated temperatures offer the highest theoretical efficiency by utilizing thermal energy to reduce electrical energy requirements, yet comprehensive frameworks integrating electrochemical modeling with process operability analysis and techno-economic optimization remain scarce in the literature. This dissertation develops a process systems framework for proton-conducting solid oxide electrolyzer cells that bridges the gap between fundamental electrochemical phenomena and industrial-scale process economics. At the …

Skin Type Diversity In Image Datasets, Neda Alipour

Doctoral

Image-based AI systems that analyse human skin are increasingly used in healthcare and computer vision applications. However, many human skin-based image datasets do not provide reliable information about skin type, making it difficult to assess whether these systems perform consistently across the full spectrum of skin colour. The objective of this thesis is to examine how skin type diversity is represented and measured in image datasets, and to evaluate the reliability of image-based skin type measurement methods under different imaging conditions. Using publicly available skin lesion image datasets as a well-defined and widely used sub-class of skin image datasets, this …