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 …

Silica Fault Mirror Development Along The Cordillera Blanca Detachment Fault, Peru, Kayla Michelle Chaudoir

All Graduate Theses and Dissertations, Fall 2023 to Present

Earthquakes occur along planes of geologic weakness called faults. Thin, light-reflective surfaces on faults are called fault mirrors and often considered signatures of previous earthquakes along these faults. The Cordillera Blanca mountain range in the Peruvian Andes provides a natural laboratory to explore meter scale exposures of fault mirrors. Three naturally formed fault mirror samples were collected from the Cordillera Blanca detachment fault which runs along the edge of the Cordillera Blanca mountain range. Prior work on this fault reveals that it is capable of destructive earthquakes every few thousand years and is a significant earthquake hazard to the surrounding …

Invasion Potential Of Nonnative Fishes Through A Large Western Dam Into A Prized And Vulnerable Ecosystem, Barrett T. Friesen

All Graduate Theses and Dissertations, Fall 2023 to Present

Native river fish face threats from habitat fragmentation, water overallocation, invasive species establishment, and powerful synergies amongst these factors. In the Colorado River Basin, USA, these threats coalesce at Glen Canyon Dam (GCD), which impounds the Colorado River to create Lake Powell, a reservoir inhabited by nonnative fish species. There is widespread concern low water level in Lake Powell may allow nonnative fish to escape through the dam, adversely affecting native fish species downstream in the Grand Canyon. In this study we characterized the seasonal distribution of nonnative fishes in the vicinity of GCD and identified environmental conditions that may …

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 …

Comparison Of Core-Collapse Supernova Explosions With 15 Solar Mass Progenitors, Chien-Hui Chen

Masters Theses

The study of core-collapse supernovae (CCSNe) helps us understand the origin and history of chemical abundances in our Universe. Previous numerical studies of CCSNe have shown the importance of non-radial motion in pre-collapse progenitors on the explosion outcome. In this thesis, I use the 2D Chimera neutrino radiation hydrodynamics code to run simulations of four models with 15 solar mass (M⊙) progenitors but different initial conditions sourced from different 1D and 2D pre-collapse burning environments. To analyze the models, I compare the explosion evolution of their nuclear abundances, shocks, neutrino heating, accretion, explosion geometry, and turbulent convection. Despite the differences …

Advancing Thermal Property Measurements And Water Management For Controlled Environment Agriculture On Earth And Beyond, Chihiro Dixon

All Graduate Theses and Dissertations, Fall 2023 to Present

Space exploration stands as one of humanity's most profound endeavors, and plant growth in space is essential for sustaining astronauts during long-duration missions. However, operating plant growth systems under reduced gravity conditions presents challenges, particularly in ensuring uniform water distribution in the root zone. Non-uniform water distribution such as excess water and/or insufficient water in the root zone can significantly impact plant yield, necessitating the need to accurately estimate water status in the root zone and understand the dynamics of water flow in plant growth media under reduced gravity conditions. The objectives of this research were to enhance the accuracy …

Analyzing Hubble Space Telescope Images Of Agn Host Galaxies With Keck Integral Field Spectra, Sebastian Contreras

Physics

In the center of most massive galaxies is a supermassive black hole (SMBH) with a mass that can range from millions to billions of solar masses. It has been observed that more massive SMBHs have a more massive host galaxy bulge, as evidenced by the larger bulge luminosity and stellar velocity dispersion, a correlation known as the BH mass - host-galaxy scaling relation. It suggests a close evolutionary connection between the growth of the SMBH and the growth of its host galaxy. If a SMBH develops an accretion disk to fuel an active galactic nucleus (AGN), it will emit radiation …

Interactions Between Nano/Micro-Sized Particles And Microbes For Agricultural And Environmental Applications, Li-Ting Yen

All Graduate Theses and Dissertations, Fall 2023 to Present

Among the challenges posed by a growing global population, diminishing arable land and water resources affected by climate change are critical for enhancing crop yields, ensuring food security, and maintaining water quality and environmental health.

Iron (Fe), an essential micronutrient, is vital to plant growth. The partially oxidized form of vivianite, metavivianite (metaVT), is reported to be a promising alternative Fe fertilizer. Previous studies have shown the effectiveness of bulk metaVT on plants grown on calcareous soil for mitigating Fe efficiency and the extremely low solubility of bulk metaVT (Ksp=10^-36) in electrolyte solutions, such as CaCl₂. …

Novel Quantum Algorithms For Noisy Intermediate-Scale Quantum (Nisq) Devices, Shikha Bangar

Doctoral Dissertations

Quantum computers hold the immense potential to revolutionize the current computing technology. However, the available quantum hardware, known as noisy intermediate-scale quantum (NISQ) devices, poses a challenge as these devices have noise and imperfect qubits. Hence, there is a critical need to develop novel algorithms specifically designed to harness the capabilities of these devices. This work aims to develop and optimize such quantum algorithms for implementation on current quantum technologies by integrating principles from physics and machine learning. First, we developed the Quantum Imaginary Time Evolution (QITE) and Quantum Lanczos (QLanczos) algorithms on discrete-variable quantum computing settings to study the …

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.

Quantum Computing And Information For Nuclear Physics, Chenyi Gu

Doctoral Dissertations

Quantum computation and quantum information, hot topics with immense potential, are making exciting strides in nuclear physics. The computational complexity of nuclear physics problems often surpasses the capabilities of classical computers, but quantum computing offers a promising solution. My research delves into the application of quantum computation and quantum information in nuclear physics.

I am curious about how to approach nuclear physics problems on a quantum computer. This dissertation studies how to prepare quantum states with quantum algorithms, as state preparation is a crucial initial step in studying nuclear dynamics. Two different quantum algorithms are studied: (i) the time-dependent method, …

Addressing Lead Exposure Disparities In Milwaukee: A Geographical Analysis Of Interventions And Equitable Strategies, Miracle Mark

Theses and Dissertations

Lead exposure is still a major public health issue, especially for children who are the most vulnerable due to the negative effects on their development. Inner-city neighborhoods are often disproportionately impacted because they tend to have older housing stock, which includes sources of lead such as lead paint and lead service lines. While many studies have examined different types of lead interventions in the U.S., including both primary and secondary interventions, little is known about the lead intervention landscape in the city of Milwaukee. Specifically, it is unclear whether the geography of intervention matches up with the geography of exposure. …

Astrophysics, Cosmology, And Fundamental Interactions With Gravitational Waves, Anarya Ray

Theses and Dissertations

Several unresolved mysteries remain in our understanding of the universe that can be elucidated with a growing catalog of gravitational wave~(GW) and multi-messenger observations of compact binary coalescences~(CBCs). Current and future catalogs, assisted by robust modeling and scalable inference frameworks, will lead to new insights into the poorly understood physics of compact binary formation, independent measurements of the cosmological expansion, and unprecedented empirical probes into the very nature of fundamental interactions. The scientific potential of GW observations from CBCs is significantly enhanced through the detection of their multi-messenger counterparts. Similarly, multi-probe explorations of compact object universal properties that combine GW …

Solving Large Job Shop Scheduling Problems: Using Graph Classification Via Graph Neural Networks To Pre-Seed A Genetic Algorithm For Machine Dispatching Rule Optimization, Isaac Schwab

Theses and Dissertations

The job shop scheduling problem is a difficult problem to solve, and it is also difficult to implement solutions found in research into real shops. In this research, a methodology is proposed to develop schedules for real shops. The methodology utilizes a genetic algorithm to select dispatching rules for each machine cell and accesses these schedules through a simulation optimization framework. The simulation framework allows for the study of random elements including variable job processing times and random machine breakdowns. This creates a robust schedule that is easy to understand, and therefore implement, while scaling to large, real-world job shops. …

Using Polonium-210 To Estimate Particulate Organic Carbon Consumption By Dreissenid Mussels In Lake Michigan, Rachel Ann Smith

Theses and Dissertations

In this study, I examine the potential of using the naturally occurring radionuclide Polonium-210 (half-life = 138.376 days) to estimate the in situ consumption of particulate organic carbon (POC) by dreissenid mussels in Lake Michigan. To estimate POC uptake, I measured the ratio of POC to particle-bound 210Po in the water column above the lakebed, as well as the inventory of 210Po being stored in mussel tissue on the lakebed at three sites with depths of 40, 50 and 80 meters. Additionally, I conducted lab incubation experiments to determine the biological half-life of 210Po in mussel tissue. These measurements were …

Using Lead-210, Bismuth-210, And Polonium-210 To Estimate Particulate Organic Carbon Flux To The Benthos Of Lake Michigan, Gage Justman Hunter

Theses and Dissertations

210Bi is a short-lived (t1/2: 5.01 days) naturally occurring radionuclide and a potential tracer of particle dynamics in high flux aquatic environments such as lakes, coastal oceans, and continental shelves. While its parent, 210Pb, and daughter, 210Po, have been used to estimate particle removal rates from the ocean, few studies have investigated the behavior of 210Bi in aquatic systems or its use as a tracer of particle export fluxes. In this study, a time series experiment was conducted where 210Pb, 210Bi, and 210Po activities were measured in rainwater and in the water column on the slope of southwestern Lake Michigan. …

Use Of Geomagnetic Paleointensity As A Correlation Tool In The Eastern Snake River Plain Lava Flows, Melissa Marie Sikes

Theses and Dissertations

The Snake River Plain volcanic province stretches 600 km from eastern Oregon across southern Idaho and into northwest Wyoming. Over the past ~14 million years, olivine tholeiitic lava flows have accumulated. To assess ongoing volcanic hazards, it is important to quantify the number, timing, and size of eruptive events. This assessment requires correlating lava flows across coreholes within the Eastern Snake River Plain. Previous paleomagnetic research applied paleomagnetic inclinations to correlate flows between coreholes. This study tests whether using geomagnetic paleointensity – in addition to inclination – can increase confidence in the correlation of these flows. Pilot samples were retrieved …

Contraction Rates For Mckean-Vlassov Stochastic Differential Equations, Dan Noelck

Theses and Dissertations

In response to the pressing need of modeling, analyzing and applying complex systems with inherent distribution- and memory-dependent dynamical behaviours, this dissertation investigates both distribution- and memory-dependent stochastic differential equations. Following the establishment of the well-posedness of these stochastic differential equations, this dissertation is focused on asymptotic properties of the underlying processes. Under suitable conditions on the coefficients of the stochastic differential equations, this dissertation derives explicit quantitative contraction rates for the convergence in Wasserstein distance for McKean-Vlasov stochastic differential equations (MVSDEs) and McKean-Vlasov functional stochastic differential equations (MVFSDEs). The obtained contraction results for MVSDEs are further utilized to demonstrate …

Evaluation Of Factors Impacting Predictor Importance Results In Multilevel Models, Soonhwa (Suna) Paek

Theses and Dissertations

Background: Dominance Analysis (DA) was originally proposed to determine the relative importance of predictor variables in OLS regression models by comparing the change in model fit (i.e., R2) resulting from adding each predictor to each possible subset model (Azen & Budescu, 2003; Azen, 2013; Budescu, 1993). Although various educational studies show that DA can provide useful information in research, the DA procedure has not been studied extensively with Multilevel Linear Models (MLMs), which are commonly used to analyze nested data structures.

Purpose: This study aimed to identify appropriate multilevel measures of fit for the DA procedure in various MLMs, and …

Cte Induced Premium Principles And Properties, Linjiao Wu

Theses and Dissertations

The traditional pricing approach in the insurance industry assumes independence among insureds, yet overlooks the complexities of interdependent risk profiles. This dissertation addresses this limitation by proposing a premium pricing model tailored for managing dependent risks, drawing inspiration from conditional tail expectation (CTE) theory. In our model, each individual insured's premium is contingent upon the collective loss surpassing a predefined threshold.

To validate the efficacy of our model, we introduce several key properties to ensure fairness and stability in premium determination among insured individuals, including diversification and monotonicity. Diversification ensures that adding one policyholder to the insured group does not …

Paleoenvironmental Constraints On Pleistocene Ice Sheets From Glacio-Volcanic Deposits In Northeast Iceland, Cameron Essex

Theses and Dissertations

There are indications that the melt-back of glaciers due to climate change can trigger new eruptions for volcanoes and magma reservoirs that rest under ice sheets. The ideal locality on Earth to study volcano-ice interactions is Iceland, an active volcanic island that has been totally covered in previous ice ages. Eruptions under glaciers produce distinctive landforms called tuyas, or table mountains, which can provide an estimate of ice thickness at the time of eruption. One research tool used to investigate ice thickness is volcanic glass, which is formed from rapid cooling of magma, and thus is abundant in the majority …

Urban Rail-Trails As Spaces Of Distributive, Procedural, And Recognitional (In)Justice, Katherine Kocisky

Theses and Dissertations

This dissertation research draws attention to urban rail-trail projects as issues of social (in)justice. Like urban greenspace, rail-trails are not an unproblematic environmental good. Large, high-profile urban rail-trails like New York City’s High Line, Chicago’s 606 Bloomingdale Trail and Atlanta’s Beltline have all received criticism for accelerating gentrification in surrounding communities, most often displacing historically excluded communities adjacent to the trail. Less research has explored relationships between urban rail-trail development and cultural displacement. This research aims to fill that gap by understanding how contemporary urban rail-trail projects are incorporating equity into their planning processes and whether urban rail-trails can be …

Spectral Characterization Of Volcanic Materials On Earth And Venus, C.J. Leight

Doctoral Dissertations

Earth and Venus are dominated by volcanic landforms, making accurate characterization of the diversity of igneous compositions on the planets’ surfaces key to understanding their geologic histories. Spectral observations in the visible-near-infrared (VNIR) and mid-infrared (MIR) provide rapid characterization of surface composition and mineralogy but are not without limitations. Spectra are sensitive to a number of factors, including observation geometry, collection method (emissivity or reflectance), grain size, phase assemblage, and composition. It is impossible to constrain the various effects of all factors when interpreting orbital data, and simplifications are made, guided by laboratory investigations.

A common simplification is to ignore …

Renormalization As A Tool For Nuclear Scattering & Binding, Chinmay Mishra

Doctoral Dissertations

Chiral effective field theory is the state-of-the-art when it comes to describing low-energy nuclear phenomena in a systematically-improvable and model-independent fashion. It is grounded in quantum chromodynamics – the fundamental theory underlying nuclear interactions – and consists of pion and nucleon degrees of freedom. In this framework, nuclear interaction is mediated by pions at long distances (in comparison to length scales at which quarks and gluons can be resolved), while finite-range “contact” terms account for the physics at short-distances. Together, they are organized into a hierarchy based on the orders (in powers of small momenta over a large momentum scale) …