Physical Sciences and Mathematics Commons^™

Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim

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

It is well known that exotic properties and phenomena emerge as structural dimensions shrink to nanoscales. We self-assembled one-dimensional chains of gold nanoparticles in solution and quantified the growth process by monitoring the redshift of localized surface plasmon resonance (LSPR). Curiously, the redshift stopped while the chains continued to rearrange as manifested by gradual reduction in the LSPR peak. Using electromagnetic simulations, we quantitatively explained the phenomena as a rapid “addition-polymerization” followed by a sharp transition to “condensation-process.” Next, recognizing the significant electric field enhancement in the interparticle gap, a photoluminescent-active Eu³⁺ ion was used to probe Surface-Enhanced Photoluminescence …

Smart Automatic Modal Hammer Predictor-Corrector Approach For Accurate Excitation Of Dynamical Systems, Mohammad Nasr

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

This research introduces an innovative solution that revolutionizes the study of linear and nonlinear dynamical systems—a smart automatic modal hammer. With its affordability and intelligent capabilities, this automatic modal hammer becomes an invaluable tool for research and industry, enabling repeatable strikes with precise force control. This system's significance becomes particularly evident when studying nonlinear systems, which heavily rely on the excitation level for their dynamics. By offering a cost-effective design this proposed system proves to be robust in accelerating research on nonlinear dynamics, providing researchers with an efficient and accessible means to delve deeper into these complex systems. The proposed …

Particle-Imbalanced Weakly Interacting Quantum Droplets In One Dimension, I. A. Englezos, P. Schmelcher, S. I. Mistakidis

Physics Faculty Research & Creative Works

We explore the formation of one-dimensional two-component quantum droplets with intercomponent particle imbalance using an ab initio many-body method. It is shown that for moderate particle imbalance each component maintains its droplet flat-top or Gaussian-type character depending on the intercomponent attraction. Importantly, large particle imbalance leads to a flat-top shape of the majority component with the minority exhibiting spatially localized configurations. The latter imprint modulations on the majority component which become more pronounced for increasing interspecies attraction. The same holds for larger mass or increasing repulsion of the minority species. Such structural transitions are also evident in the underlying two-body …

Novel Emergent Phases In A Two-Dimensional Superconductor, Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, Anjana Dogra, Rajesh Narayanan, Thomas Vojta, Aveek Bid

Physics Faculty Research & Creative Works

In this letter, we report our observation of an extraordinarily rich phase diagram of a LaScO₃/SrTiO₃ heterostructure. Close to the superconducting transition temperature, the system hosts a superconducting critical point of the Infinite-randomness type characterized by an effective dynamical exponent ν z that diverges logarithmically. At lower temperatures, we find the emergence of a magnetic field-tuned metallic phase that co-exists with a quantum Griffiths phase (QGP). Our study reveals a previously unobserved phenomenon in 2D superconductors—an unanticipated suppression of the QGP below a crossover temperature in this system. This concealment is accompanied by the destruction of the …

Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We demonstrate the controllable generation of distinct types of dispersive shock waves emerging in a quantum droplet bearing environment with the aid of steplike initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between mean-field repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena being designated by the real and the imaginary speed of sound, respectively. Specifically, the symmetries of the extended Gross-Pitaevskii model led to a three-parameter family, encompassing two densities and a relative velocity of the underlying Riemann problem utilized herein. Surprisingly, dispersive shock …

Factors Impacting Users’ Willingness To Adopt And Utilize The Metaverse In Education: A Systematic Review, Mousa Al-Kfairy, Soha Ahmed, Ashraf Khalil

All Works

Purpose: This study explores the factors influencing the adoption and acceptance of Metaverse technologies in educational settings. Despite the growing interest in immersive educational environments provided by the Metaverse, there is a lack of comprehensive understanding regarding the elements that affect user engagement and acceptance. This paper aims to bridge this gap through a systematic review of empirical studies that apply Information Systems theories such as TAM, UTAUT, TPB, and their extensions. Methods: A total of 35 empirical studies were analyzed using a methodical review approach. The research methodologies employed in these studies include surveys, structural equation modeling, and interviews, …

A Comprehensive Dataset For Arabic Word Sense Disambiguation, Sanaa Kaddoura, Reem Nassar

All Works

This data paper introduces a comprehensive dataset tailored for word sense disambiguation tasks, explicitly focusing on a hundred polysemous words frequently employed in Modern Standard Arabic. The dataset encompasses a diverse set of senses for each word, ranging from 3 to 8, resulting in 367 unique senses. Each word sense is accompanied by contextual sentences comprising ten sentence examples that feature the polysemous word in various contexts. The data collection resulted in a dataset of 3670 samples. Significantly, the dataset is in Arabic, which is known for its rich morphology, complex syntax, and extensive polysemy. The data was meticulously collected …

Tool-Sensed Object Information Effectively Supports Vision For Multisensory Grasping, Ivan Camponogara, Alessandro Farnè, Robert Volcic

All Works

Tools enable humans to extend their sensing abilities beyond the natural limits of their hands, allowing them to sense objects as if they were using their hands directly. The similarities between direct hand interactions with objects (hand-based sensing) and the ability to extend sensory information processing beyond the hand (tool-mediated sensing) entail the existence of comparable processes for integrating tool- and hand-sensed information with vision, raising the question of whether tools support vision in bimanual object manipulations. Here, we investigated participants' performance while grasping objects either held with a tool or with their hand and compared these conditions with visually …

Quantinar: A Blockchain Peer-To-Peer Ecosystem For Modern Data Analytics, Raul Bag, Bruno Spilak, Julian Winkel, Wolfgang Karl Hardle

Sim Kee Boon Institute for Financial Economics

The power of data and correct statistical analysis has never been more prevalent. Academics and practitioners require nowadays an accurate application of quantitative methods. Yet many branches are subject to a crisis of integrity, which is shown in an improper use of statistical models, p-hacking, HARKing, or failure to replicate results. We propose the use of a Peer-to-Peer (P2P) ecosystem based on a blockchain network, Quantinar, to support quantitative analytics knowledge paired with code in the form of Quantlets or software snippets. The integration of blockchain technology allows Quantinar to ensure fully transparent and reproducible scientific research.

High Prevalence Of Artifacts In Optical Coherence Tomography With Adequate Signal Strength, Wei-Chun Lin, Aaron Coyner, Charles Amankwa, Abigail Lucero, Gadi Wollstein, Joel Schuman, Hiroshi Ishikawa

Wills Eye Hospital Papers

PURPOSE: This study aims to investigate the prevalence of artifacts in optical coherence tomography (OCT) images with acceptable signal strength and evaluate the performance of supervised deep learning models in improving OCT image quality assessment.

METHODS: We conducted a retrospective study on 4555 OCT images from 546 patients, with each image having an acceptable signal strength (≥6). A comprehensive analysis of prevalent OCT artifacts was performed, and five pretrained convolutional neural network models were trained and tested to infer images based on quality.

RESULTS: Our results showed a high prevalence of artifacts in OCT images with acceptable signal strength. Approximately …

A Framework For The Foundation Of The Philosophy Of Artificial Intelligence, Emily Barnes, James Hutson

Faculty Scholarship

In recent years, the rapid advancement of artificial intelligence (AI) technology has sparked profound questions about the nature of machine intelligence and the possibility of AI consciousness. As AI systems become increasingly sophisticated, examining their philosophical foundations has become imperative. This article investigates the intricate relationship between AI and existential thought, aiming to establish a comprehensive framework for understanding AI's philosophical underpinnings. The historical development of AI, from symbolic AI to contemporary machine learning paradigms, highlights the increasing complexity and sophistication of AI systems, prompting significant philosophical debates about machine consciousness. Theoretical models such as the Independent Core Observer Model …

Exponential Qubit Reduction In Optimization For Financial Transaction Settlement, Elias X. Huber, Benjamin Y. L. Tan, Paul Robert Griffin, Dimitris G. Angelakis

Research Collection School Of Computing and Information Systems

We extend the qubit-efficient encoding presented in (Tan et al. in Quantum 5:454, 2021) and apply it to instances of the financial transaction settlement problem constructed from data provided by a regulated financial exchange. Our methods are directly applicable to any QUBO problem with linear inequality constraints. Our extension of previously proposed methods consists of a simplification in varying the number of qubits used to encode correlations as well as a new class of variational circuits which incorporate symmetries thereby reducing sampling overhead, improving numerical stability and recovering the expression of the cost objective as a Hermitian observable. We also …

A Flood Of Consequences In Louisville, Kentucky: Using Hgis To Track Refugees Impacted By The 1937 Ohio River Flood, Trevor Harry

Masters Theses & Specialist Projects

The Ohio River flood of 1937 was the most devastating flood in the recorded history of the Ohio River Valley and is commonly referred to as the “Great Flood of 1937”. In January 1937, after nearly two months of continuous precipitation, over 60% of the city of Louisville, Kentucky, was flooded and at least 23,000 residents were displaced. The purpose of this research was to document, map, and compare the pre-flood residential locations, evacuation destinations, and post-flood residential locations of African American and White Louisville refugees from the 1937 Ohio River flood. Socioeconomic information from the manuscript versions of the …

The Role Of Efflux Pump Inhibitor In Enhancing Antimicrobial Efficiency Of Silver Nanoparticles And Methylene Blue As An Effective Photodynamic Therapy Agent, Yaran Allamyradov

Masters Theses & Specialist Projects

Efflux pumps are critical active transport systems utilized by cells to expel toxic substances, including antibiotics and photosensitizer complexes, thereby contributing to antimicrobial resistance. Efflux pump inhibitors (EPIs), which are compounds that obstruct the transport of molecules through these pumps, play a pivotal role in enhancing the effectiveness of antimicrobial therapies against pathogens. This study investigates the effects of the EPI reserpine on the photodeactivation rate of pathogens when used in conjunction with silver nanoparticles (Ag NPs) and methylene blue (MB), a common photosensitizer.

Our research reveals that the application of reserpine, in combination with Ag NPs and MB, leads …

Surface Patterning On Zirconia Dental Implants Via Laser-Induced Shockwave Imprinting, Inomjon Majidov

Masters Theses & Specialist Projects

Zirconia is rapidly becoming a preferred alternative to titanium in dental applications, primarily due to its aesthetic resemblance to natural teeth. This material’s tooth-like color avoids the aesthetic issues associated with the grey metal tint of titanium implants. Additionally, zirconia is hypoallergenic, making it an ideal choice for patients with metal sensitivities or allergies. Despite these advantages, zirconia generally exhibits lower biocompatibility and osseointegration compared to titanium implants. This study investigates laser-assisted, controlled imprinting technique on zirconia surfaces to enhance these properties. Our research used zirconia pellets, produced from powdered monoclinic zirconia pressed in a pellet press machine. Two methods …

Polygenetic Cave Sedimentation And Speleogenesis In The Mccloud Limestone Of Northern California, Niles Lathrop

Masters Theses & Specialist Projects

Caves in the Permian-aged, McCloud Limestone of the Klamath Mountains of Northern California preserve a diverse range of clastic sediments that represent broad-scale variations in paleo-hydrologic conditions and transport mechanisms that hint at varied modes of speleogenesis through local landscape development. Caves in the McCloud Limestone exhibit a range of cave passage geometries and arrangements that suggests periods of both hypogene and epigene cave development through temporal and spatial scales. This study evaluates the variability in the distribution, mineralogy, and transport mechanisms of clastic-cave sediments in seven hydrologically-distinct caves in the McCloud Limestone to establish relationships between clastic-cave sedimentation and …

Contaminant Transport Mechanisms And Source Tracking In Karst Groundwater Systems Under Agricultural Land Use, Shreya Pandey

Masters Theses & Specialist Projects

Karst areas in general face severe groundwater contamination problems that can degrade their water quality. In comparison to other landscapes, groundwater within karst regions is more susceptible to contamination. The situation gets worse when agriculture is practiced in these karst regions, because the nutrients and bacteria like nitrates and E. coli (Escherichia coli) are released into the groundwater systems which contaminate the water quality of those karst groundwater systems. This research aims to study the impacts of these contaminants, specifically nitrates and E. coli., by identifying the contaminant transport mechanisms and source tracking of these contaminants in the groundwater under …

Comprehensive Climate Vulnerability Assessment Of A Regional Karst Landscape For Hazard Mitigation Planning, Kara Brunot

Masters Theses & Specialist Projects

Climate change is the global phenomena affecting all sectors of society by creating conditions more conducive for the occurrence of extreme weather events. It is projected that the intensity and frequency of events will increase. Flooding, in particular, is projected to increase in frequency due to more intense precipitation events. Karst landscapes are especially vulnerable to climate change impacts because of their unique hydrology and geology. Karst flooding is most likely to occur from prolonged or intense rain events, which climate change will likely make more feasible. Areas are disproportionately affected by climate change due to population demographics and environmental …

Landuse And Microplastic Transport In Karst Groundwater Of South-Central Kentucky, Katie Norman

Masters Theses & Specialist Projects

Groundwater in karst areas is susceptible to contamination from various sources of pollution. Microplastics are a prevalent source of pollution entering groundwater. This study examines karst groundwater in three areas of investigation. One point of interest is an area that is impacted by urban activities, the Lost River Groundwater Basin, which includes water drainage from the City of Bowling Green, Kentucky. Another study location is Great Onyx (GO) Spring, which is a part of the Great Onyx Groundwater Basin located in Mammoth Cave National Park, Kentucky, and that is relatively unimpacted by urban activities. The third point of interest is …

Perceptions And Visual Awareness Of Urban Karst Flooding To Inform Preparedness Planning And Management Actions, Grace Hermann

Masters Theses & Specialist Projects

Awareness and perception of flooding can heavily affect how an individual or community prepares for flooding. Flood awareness can be affected by factors like past flood experience and demographics. Flood experience and demographics can affect flood awareness differently based on factors including the types and cause of flooding. Flooding in karst landscapes can vary from other types of flooding and neither perception nor awareness of karst flooding has been directly studied before. This study explored both expert and non-expert flood awareness and perception and flood policies in a karst landscape through interviews with experts, surveys, and cognitive mapping activities. The …

Catalytic Hydrogenation Of Co2 In Water And Ionic Liquids Using Platinum On Carbon, Kristin Collins

Masters Theses & Specialist Projects

Platinum-on-carbon (Pt/C) is a commercially-available catalyst that has been used in the literature to benchmark the performance of catalysts produced using platinum/cobalt alloy nanoparticles. Initially, we intended to build upon this example by synthesizing shape-controlled platinum/cobalt alloy nanoparticles in ionic liquids and compare their ability to catalyze the hydrogenation of CO₂ to methanol against Pt/C as a benchmark, with the idea that ionic liquids may improve catalysis. However, we found that Pt/C was unable to catalyze the hydrogenation of CO₂ to methanol. In an attempt to track the source of this discrepancy, Pt/C was characterized using thermogravimetric analysis …

Development And Application Of The Sinkhole Hazard Risk Index To Inform Karst Policy And Mitigation Planning, Meghan Puente

Masters Theses & Specialist Projects

Sinkholes are geologic hazards that occur in karst landscapes and can be highly destructive and costly. Sinkhole mitigation plans and development policies are nonexistent at the federal level within the United States and vary significantly at the state level. The lack of a unified standard for sinkhole mitigation planning is partly due to a lack of available data and resources needed to assess sinkhole risk. While there are established sinkhole assessments within the literature, they focus more on the detection and prediction of sinkholes rather than a holistic approach to risk assessment. The goal of this study is to create …

Evaluating Stormwater Erosion Prevention And Sediment Control Best Management Practices Using High-Resolution Rainfall Monitoring And Field-Based Assessment Tools, Brittany Pekara

Masters Theses & Specialist Projects

Advancing stormwater management methods and technology is critical as runoff from impermeable surfaces increases with urbanization and development. Stormwater runoff is highly susceptible to contamination from non-point source pollution and causing flood impacts following rain events, which varies spatially and temporally in an urban landscape. To counteract the impacts of contamination and drainage issues, Best Management Practices (BMPs) are implemented to reduce the effects of stormwater runoff; however, the unpredictable nature of storm events can make methods for effectively monitoring impacts difficult in trying to capture first flush inputs, flood threats, and sedimentation sources. This research utilizes a highresolution rainfall …

How Can Event Attribution Science Underpin Financial Decisions On Loss And Damage?, Dim Coumou, Paola A. Arias, Ana Bastos, Charlotte Kendra Z. Gotangco Gonzales, Gabriele C. Hegerl, Pandora Hope, Christopher Jack, Friederike Otto, Fahad Saeed, Olivia Serdeczny, Theodore G. Shepherd, Robert Vautard

Environmental Science Faculty Publications

With climate extremes hitting nations across the globe, disproportionately burdening vulnerable developing countries, the prompt operation of the Loss and Damage fund is of paramount importance. As decisions on resource disbursement at the international level, and investment strategies at the national level, loom, the climate science community’s role in providing fair and effective evidence is crucial. Attribution science can provide useful information for decision makers, but both ethical implications and deep uncertainty cannot be ignored. Considering these aspects, we articulate a vision that integrates established attribution methods and multiple lines of evidence within a coherent logical framework.

Bridging The Gap: Ai And The Hidden Structure Of Consciousness, Emily Barnes, James Hutson

Faculty Scholarship

The quest to develop Artificial Intelligence (AI) systems that possess human-like consciousness necessitates a deep dive into both theoretical and practical aspects underpinning this ambitious goal. This article builds on initial philosophical explorations of AI consciousness by examining the intricate and often hidden structures that may facilitate conscious experiences in AI. Drawing from concepts in cognitive science and neuroscience, the article elucidates how AI systems can be designed to replicate the structural and functional aspects of human consciousness. The discussion includes the Hierarchy of Spatial Belongings proposed by Forti (2024), frameworks like the Integrated Information Theory (IIT), and models linking …

Robust Hydropower Planning Balances Energy Generation, Carbon Emissions And Sediment Connectivity In The Mekong River Basin, M. Tangi, Rafael Schmitt, Rafael M. Almeida, S. Bossi, Alexander S. Flecker, F. Sala, A. Castelletti

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We present a framework for strategic dam planning under uncertainty, which includes GHG emissions mitigation as a novel objective. We focus on the Mekong River Basin, a fast‐developing region heavily relying on river‐derived ecosystem services. We employ a multi‐objective evolutionary algorithm to identify strategic dam portfolios for different hydropower expansion targets, using process‐related and statistical models to derive indicators of sediment supply disruption and GHG emissions. We introduce a robust optimization approach that explores variations in optimal portfolio compositions for more than 5,000 state‐of‐ the‐world configurations, regarding sediment origins and trapping and GHG emissions. Thus, we can rank dam projects' …

Artificial Intelligence, Work, And The Future Of Education, Daniel Brown

Presentations

No abstract provided.

Observation Of Gravitational Waves From The Coalescence Of A 2.5–4.5 M⊙ Compact Object And A Neutron Star, A. Abac, R. Abbott, I. Abouelfettouh, F. Acernese, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

We report the observation of a coalescing compact binary with component masses 2.5–4.5 M⊙ and 1.2–2.0 M⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5 M⊙ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find …

Nonfactoid Question Answering As Query-Focused Summarization With Graph-Enhanced Multihop Inference, Yang Deng, Wenxuan Zhang, Weiwen Xu, Ying Shen, Wai Lam

Research Collection School Of Computing and Information Systems

Nonfactoid question answering (QA) is one of the most extensive yet challenging applications and research areas in natural language processing (NLP). Existing methods fall short of handling the long-distance and complex semantic relations between the question and the document sentences. In this work, we propose a novel query-focused summarization method, namely a graph-enhanced multihop query-focused summarizer (GMQS), to tackle the nonfactoid QA problem. Specifically, we leverage graph-enhanced reasoning techniques to elaborate the multihop inference process in nonfactoid QA. Three types of graphs with different semantic relations, namely semantic relevance, topical coherence, and coreference linking, are constructed for explicitly capturing the …

Causvsr: Causality Inspired Visual Sentiment Recognition, Xinyue Zhang, Zhaoxia Wang, Hailing Wang, Jing Xiang, Chunwei Wu, Guitao Cao

Research Collection School Of Computing and Information Systems

Visual Sentiment Recognition (VSR) is an evolving field that aims to detect emotional tendencieswithin visual content. Despite its growing significance, detecting emotions depicted in visual content,such as images, faces challenges, notably the emergence of misleading or spurious correlationsof the contextual information. In response to these challenges, we propose a causality inspired VSRapproach, called CausVSR. CausVSR is rooted in the fundamental principles of Emotional Causalitytheory, mimicking the human process from receiving emotional stimuli to deriving emotional states.CausVSR takes a deliberate stride toward conquering the VSR challenges. It harnesses the power of astructural causal model, intricately designed to encapsulate the dynamic causal …