Digital Commons Network^™

First-Principles Insights Into Binary Oxide Systems Under Extreme Pressure, Daniel Schacher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pressure is powerful tool by which one can manipulate the properties of materials. In this work we utilize pressure to explore binary oxide systems and characterize their structural and electronic properties. The observation of anomalous structural and electronic behavior in the rutile to CaCl2 phase transition in SnO2 led to the prediction that such behavior is inherent to all oxides experiencing such a phase transition sequence.[1] Here, the ultra-wide band gap semiconductor GeO2 is confirmed to exhibit anomalous behavior during the rutile to CaCl2 phase transition. A phase pure rutile GeO2 sample synthesized under high-pressure, high-temperature, conditions is probed using …

Towards Spatial Inversion Of Aerial Gamma-Ray Survey Data For Measurement Of Naturally Occurring Radioactivity, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma-ray surveying (AGRS) is used in geologic and environmental contexts to provide data on the surface spatial distribution of naturally occurring radioactive material (NORM) or other gamma-ray-emitting isotopes. The standard data reduction workflow for AGRS data involves a process whereby pointwise gamma-ray spectral data are denoised, corrected for numerous sources of background radiation and aircraft height, and are finally converted to physical values by empirical conversion factors. The reduced pointwise data are then typically spatially interpolated to form a continuous surface map.

This dissertation introduces and explores a novel spatial inversion method for reduced AGRS data that considers aircraft …

Nuclear Transparency Of Photoproduced Rho-0 Mesons., Bhesha Raj Devkota

Theses and Dissertations

Photonuclear reactions using a real photon beam offer a unique opportunity to explore fundamental aspects of QCD within the nuclear medium. The experiment E12-19-003, conducted at Jefferson Lab’s Hall D in 2021, aimed to look for the transition from hadronic to partonic degrees of freedom and to explore the predicted QCD phenomenon known as color transparency in photons, mesons, and baryons. A key objective was to examine the transition of the photons from a resolved (hadronic fluctuation) configuration to a point-like electromagnetic probe. The experiment utilized liquid deuterium, helium, and carbon foils as target nuclei, which were probed by photon …

Long-Term Calibration And Validation Of Stability Of The Auger Engineering Radio Array Using The Diffuse Galactic Radio Emission, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, R. Aloisio, B. Fick, Et Al.

Michigan Tech Publications

The Auger Engineering Radio Array (AERA) measures radio emission from high-energy extensive air showers. Consisting of 153 autonomous radio-detector stations spread over 17 km^2, it detects radio waves in the frequency range of 30 to 80 MHz. Accurate characterization of the detector response is crucial for proper interpretation of the collected data. Previously, this was achieved through laboratory measurements of the analog chain and simulations and measurements of the antenna's directional response. In this paper, we perform an absolute calibration using the continuously monitored sidereal modulation of the diffuse Galactic radio emission. Calibration is done by comparing the average frequency …

Measurements Of Water-Film Thickness On Cave Walls And Speleothems, Alexandre Honiat, Salaheddine Skali-Lami, François Bourges, Bruno Lartiges

International Journal of Speleology

The water-film that coats cave walls and speleothems is a key player for the regulation of cave microclimate and the control of speleothem growth. In this paper, we demonstrate the capability of a confocal optical sensor to quantitatively measure on-site the rapid variations of water-film thickness when dripping, active condensation, or dryness occur on walls of various caves. Results obtained from a sample of four prehistoric caves and one stalagmite cave from Southwest France, indicate that the measurable thickness of water-films is generally in the 25-70 µm range for cave walls and reaches 200-300 µm on the horizontal plane of …

High-Resolution Lidar Observations Of Sedimentation-Induced Size Sorting Of Droplets Near A Laboratory Cloud Top, Fan Yang, Yong Meng Sua, Zipei Zheng, Jesse Anderson, Hamed F. Sadi, Jae Min Yeom, Suryadev Pratap Singh, Pei Hou, Will Cantrell, Ernie Lewis, Alex Kostinski, Raymond Shaw

Michigan Tech Publications

No abstract provided.

Early Warning Detection Of Gravitational Waves With Sgnl, Megan Norris

Honors Theses

Gravitational waves (GWs) provide a whole new spectrum with which to observe astrophysical events. Multi-messenger observations including GWs are of particular interest, and these are best facilitated by early warning searches of GWs, which are typically aimed at detecting binary neutron star (BNS) mergers. This work provides an introductory overview of gravitational waves and summarizes the origins and basic physical properties of neutron stars and black holes in binary systems, focusing on BNS mergers and the detection of gravitational waves with LIGO using a modeled search. We assess the performance of a new GW search pipeline called SGNL to evaluate …

Establishing Convergence Thresholds For Pre-Trajectory Sampling With Batched Execution Across Random Quantum Circuits, Taylor L. Eskew, Jerome F. Gonthier, Taylor L. Patti, Andrew N. Jordan

Student Scholar Symposium Abstracts and Posters

A crucial aspect of validating quantum protocols is understanding the noise produced by quantum computing devices. Using simulations that can replicate this noise allows for a lower-cost alternative to hardware experiments. Stochastic, so-called "trajectory" methods are often used as a quadratically reduced approximation to density matrix simulations, but traditional implementations have limited sampling capacity and provide no error-based metadata. The Pre-Trajectory Sampling with Batched Execution (PTSBE) [Patti et al., 2025] algorithm provides a solution by combining fine-tuned, well-documented noise sampling with computational intermediate caching.

While the original work is effective on quantum error correction circuits, its performance on general circuits …

Lead Sources Detected In Manila's Air After The Phase-Out Of Leaded Gasoline, Grace Betito, Paola Angela Bañaga, Maria Obiminda L. Cambaliza, Melliza Templonuevo Cruz, James Bernard Simpas, Mengli Chen, Jariya Kayee, Armin Sorooshian, Rachel A. Braun, Alexander B. Macdonald

Ateneo Atmospheric Physics Laboratory

Abstract

The global phase-out of leaded gasoline marked a major milestone in pollution control, yet modern uses of lead (Pb) continue to pose significant health risks, especially in low- and middle-income countries. In the Philippines, significant data gaps still exist despite increasing exposure. This study presents to the best of our knowledge, the first Pb isotopic fingerprinting of atmospheric aerosols in Metro Manila, Philippines, covering fine (0.56–1 μm) and coarse (5.6–10 μm) fractions, collected in 2018–2019. Results show that local sources, mainly industrial activities (45–62 %) and fossil fuel combustion (30–45 %), are now the dominant contributors to airborne Pb, …

From Inside The Recording Studio, Mckayla J. Adkison

Capstone Projects and Master's Theses

This project documents the historical, technical, and creative significance of recording studios through both industry examples and the design and construction of a personal backyard studio. By examining iconic studios such as Abbey Road and Capitol Records, the paper highlights how technological innovation, acoustic engineering, and architectural design have shaped the evolution of recorded music. These concepts are then applied to the planning and construction of a custom-built recording studio, emphasizing room dimensions, sound isolation techniques, acoustic treatment, lighting, and sustainable design choices. In addition, the project addresses the importance of aesthetics and emotional comfort in creating a space that …

Investigating Molecular Rotation And Vibration With Ultrafast Electron Diffraction, Haoran Zhao

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ultrafast electron diffraction (UED) has emerged since the late 20th century as a powerful technique for resolving molecular dynamics. With its high spatial and temporal resolution, UED can now measure rotational motion induced by linearly polarized, nonresonant, nonadiabatic laser pulses—one of the fundamental molecular degrees of freedom with broad applications. By combining laser-induced alignment with UED, new capabilities such as three-dimensional structural retrieval and isotope detection have been demonstrated, as discussed in Chapter 2.

In Chapter 3, three symmetry relations in the coefficients of rotational wave packets are identified and derived, reducing the computational cost of simulating asymmetric-top molecular alignment …

Coupled Machine Learning Models: Combining Observations And Numerical Analysis In A Physics-Regularized Approach, Austin B. Schmidt

LSU New Orleans Theses and Dissertations

This dissertation investigates surrogate modeling for fixed-location environmental forecasting using novel data-combination techniques. The work surveys the landscape of observational measurements and numerically generated data, identifying similar research and gaps in current methodologies. The ratio-coupled training framework is introduced to combine two data sources per predicted feature through a tunable parameter that weights training signal strength. An optimization scheme is developed to simultaneously tune surrogate weights and the coupled signal ratio, allowing relative influence between signals to act as an explicit regularizer. Three case studies demonstrate the methodology and approach in a variety of contexts. The first study is based …

Content And Consequences: Impact Of Representation In Stem Higher Education Instructional Content On Marginalized Students, Nichole Ventura

Doctorate in Education

This qualitative study examined representation of historically marginalized students in STEM instructional content at the higher education level and its impact on their learning experiences. Despite growing diversity initiatives in STEM enrollment, curricular materials often fail to reflect the identities of underrepresented students. Using critical theory and interpretivist approaches, this research investigated how representation—or its absence—shapes students' sense of belonging, academic identity formation, and persistence. Through semi-structured interviews with undergraduate students from historically marginalized backgrounds, and purposeful sampling, this study captured the lived experiences of students engaging with STEM instructional materials. Interview protocols explored how students perceive their representation in …

Quantum Entanglement As A Resource For Coordinating Navigation, Aamir Ahmad

Theses and Dissertations

John Clauser, Michael Horne, Abner Shimony, and Richard Holt (CHSH) originally formulated the CHSH game as an experiment to establish entanglement as a quantum mechanical phenomenon that could not be predicted by classical theories. I will apply the quantum strategy used in the CHSH game to demonstrate that it also establishes a structure that employs entanglement as a resource to enable coordination without communication in the context of navigation.

Design And Evaluation Of Gamified Kahoot Modules For Improving Engagement And Conceptual Understanding Of Introductory Physics Students, Yaritza Villarreal

Theses and Dissertations

This study investigates the effectiveness of gamified learning modules in enhancing the engagement and conceptual understanding of introductory physics students. The first phase of this study focused on the design and development of gamified learning modules for selected topics in introductory physics. The modules were developed by integrating principles of Backward Design, following an escape-room theme with interactive scenarios, and incorporating classic game elements (e.g., points and leaderboards).

The second phase examined the effectiveness of the gamified Kahoot modules using a pretest-posttest control-group design. Sixty-eight (68) students were equally randomly assigned to the control and experimental groups. The experimental group …

Development Of Oxide And Oxynitride Thin Films For Advanced Optical Applications, Nathan Christopher Episcopo

Open Access Theses & Dissertations

To develop Ga2O3 and TiOₓNᵧ thin films for optical applications, the process–structure–properties relationship was investigated using a comprehensive set of characterization techniques to establish the atomic structure and composition of the films in relation to the deposition conditions. The results provide critical insights into how deposition parameters influence the atomic structure and composition during magnetron sputtering. Furthermore, the correlation between atomic structure and composition with the optical and electrical properties of the films was examined to determine how variations in these factors affect functional performance. Collectively, these findings offer the necessary information to target desirable optical properties for Ga2O3 and …

Lorentz Invariance And Quantum Coordination: A Neo-Aristotelian Framework For Entanglement And Relativity, Angel Rafael Sosa Muniz

Open Access Theses & Dissertations

The phenomenon of quantum entanglement has been at the center of heated debates among physicists and philosophers since the dawn of the quantum era. The early discussions initiated by Einstein, Podolsky, and Rosen—regarding potential violations of the Principle of Relativity by entangled particles, expressed in the so-called “EPR Paradox”—ultimately culminated in the demonstration of Bell’s theorem and its violations. Since then, philosophers of science and physicists have developed multiple proposals attempting to account for the ontological status of quantum formalism and its possible tension with relativistic principles. This thesis contributes to these efforts by advancing a Neo-Aristotelian ontological framework inspired …

First Principles Calculation Of Electron-Phonon Coupling In Nonequilibrium Quantum Materials, Chendi Xie

All Dissertations

This dissertation combines first-principles computation and light-induced nonequilibrium analysis to understand and control electron–phonon coupling (EPC) and emergent many-body phenomena in quantum materials, in both equilibrium and nonequilibrium states.

Chapters 1 and 2 build the theoretical and computational foundation, beginning with electron and phonon self-energies, linewidths, and perturbation theory for EPC, followed by density functional theory (DFT) and density functional perturbation theory (DFPT), which serve as the first-principles workhorses used throughout. Chapter 3 reviews Bardeen-Cooper-Schrieffer (BCS) and Migdal-Eliashberg theory, including the BCS gap - transition temperature (T_c) relation and the strong-coupling generalization, and delineates the practical validity bound …

On The Scalability Of Anisotropic Mesh Adaptation On Distributed And Shared Memory Architectures For Numerical Approximations, Kevin Mark Garner Jr.

Computer Science Theses & Dissertations

Mesh generation is a critical component in numerical approximations of Partial Differential Equations (PDEs). One such example includes Computational Fluid Dynamics (CFD), as CFD simulations in turn are crucial for applications in many industries, such as personalized healthcare and the design of aerospace vehicles. Generating high quality meshes for large-scale CFD problems presents a significant bottleneck in the CFD workflow. This dissertation proposes “fast,” parallel 3D mesh generation methodologies that are designed to leverage the concurrency offered by emerging High-Performance Computing (HPC) architectures. First, a distributed memory method is presented that integrates a sequential state-of-the-art isotropic, advancing front local reconnection-based …

Evaluation Of Ocean Lidar Enhancement Through Miniaturization And Gated Pmt-Based Range Extension, Chandler Austin Slater

OES Theses and Dissertations

Oceanographic lidar systems remotely characterize the vertical structure of the upper ocean by recording the light backscattered from a laser pulse as it propagates through the water column. Historically these systems have been constrained by limited detection ranges, often capturing only a portion of the illuminated water column, typically fading to noise around the 10% isolume. A primary constraint has been the limited dynamic range of digitizers, which inhibits the ability to resolve both intense near-field and faint far-field backscatter signals within a single acquisition. To address this, we developed a novel optical lidar system incorporating gated photomultiplier tubes (PMTs) …

Relativistic Three Particle Scattering, Md Habib E Islam

Physics Theses & Dissertations

In this dissertation, we develop and apply a relativistic framework for studying three-body scattering amplitudes, their analytic structure, and the emergence of universal phenomena such as the Efimov effect. The work integrates three complementary components.

First, we introduce a systematically improvable numerical method for solving relativistic three-body integral equations in momentum space. By discretizing the continuum problem into finite matrix equations and extrapolating to the continuum limit, we obtain stable partial-wave amplitudes in the presence of a two-body bound state. Two complementary treatments of the pole contribution are implemented and shown to reproduce previous finite volume results, with controlled estimates …

Time-Resolved 3d Momentum Spectroscopy In Continuous Wave Atomic Photoionization Experiments, K. L. Romans, B. P. Acharya, A. H.N.C.De Silva, K. Foster, O. Russ, Daniel Fischer

Physics Faculty Research & Creative Works

An experimental continuous-wave (cw) pump-probe scheme is demonstrated by investigating the population and photoionization dynamics of an atomic system. In particular, 6Li atoms are initially prepared in optically pumped 22S1/2 and 22P3/2 states before being excited via multi-photon absorption from a tunable femtosecond laser. The subsequent cascade back to the ground state is analyzed by ionizing the atoms in the field of a cw optical dipole trap laser. Conventional spectroscopic methods, such as standard cold-target recoil ion momentum spectroscopy or velocity map imaging, cannot provide simultaneous momentum and time-resolved information on an event-by-event basis for the system investigated here. The …

Identification Of Novel Tat-I24-Related Peptides With Antiviral Activities, Hanna Harant, Siegfried Hofinger, Reingard Grabherr, Zsolt Ruzsics, Hartmut Hengel

Michigan Tech Publications

To identify novel peptides with potential antiviral activities, a database search was performed based on the primary sequence of the peptide I24 (CLAFYACFC), the effective part of the antiviral peptide TAT-I24 consisting of peptide I24 and the cell penetrating TAT-peptide (amino-acids 48–60, GRKKRRQRRRPPQ). A Protein BLAST search identified several sequences with high similarity to I24 in diverse proteins, some of which are known to be involved in the interaction with nucleic acids. Selected sequences and newly designed variants of I24 were synthesized as TAT fusion peptides and tested for antiviral activity in two well-established models: baculovirus transduction of HEK293 cells …

Optical, Electrical, And Structural Properties Of Nio Thin Films, Derived By Sol–Gel Method, Tatyana Ivanova, Antoaneta Harizanova, Nikolay Petkov

Physical Sciences Publications

NiO films were successfully deposited by sol–gel spin coating on Si, glass, and ITO-covered glass substrates. The impact of the film thickness (the different number of layers), annealing temperatures (from 300 to 500 °C), and the substrate type on the crystal structure, film morphology, optical, and vibrational properties was investigated. X-ray diffraction (XRD) revealed a polycrystalline structure and the appearance of the cubic NiO phase. Field Emission Scanning Electron Microscopy (FESEM) was applied to explore the surface morphology of NiO films, deposited on glass and ITO substrates. The oxidation states of Ni were determined by X-ray photoelectron spectroscopy (XPS). The …

Modulation Of The Semi-Annual Oscillation By Stratospheric Sudden Warmings As Seen In The High-Altitude Jawara Re-Analyses, Jiarong Zhang, Yvan Orsolini, Kaoru Sato

All Physics Faculty Publications

The semi-annual oscillation (SAO) dominates seasonal variability in the equatorial stratosphere and mesosphere. However, the seasonally dependent modulation of the SAO in the stratosphere (SSAO) and mesosphere (MSAO) by sudden stratospheric warmings (SSWs) in the Arctic has not been investigated in detail. In this study, we examine the seasonal evolution of the SAO during 16 major SSW events spanning 2004 to 2024 using the Japanese Atmospheric General Circulation Model for Upper Atmosphere Research Data Assimilation System Whole Neutral Atmosphere Re-analysis (JAWARA). Basic features of the SAO are well captured by JAWARA, as evidenced by the SSAO and MSAO appearing at …

Fish-Spec: Fast Identification System For Handheld Spectroscopy And Species Classification, Mitchell Sueker, Nicholas Mackinnon, Gregory Bearman, Amanda Tabb, Diane Kim, Rosalee S. Hellberg, Alireza Akhbardeh, Hamid Reza Marateb, Jianwei Qin, Moon Kim, Fartash Vasefi, Hossein Kashani Zadeh

Food Science Faculty Articles and Research

Accurate fish species identification is critical to prevent mislabeling and fraud in the seafood industry. We present a handheld multi-mode point spectroscopy system that combines fluorescence (365 and 395 nm excitation) and reflectance measurements in the visible to near-infrared (∼350–900 nm) and short-wave infrared (∼900–1700 nm) regions for rapid, non-destructive classification of fish fillets. Tissue spectra were acquired at 25 positions on 68 fillets from 11 species, in both frozen and thawed states. Feature-level fusion across all four modes enabled higher classification accuracy than any single mode alone. A global machine-learning model classified all species with 85 ± 2.8 %, …

Stars And Shapes: An Investigation Of Stripped Envelope Supernovae Structures Using Spectropolarimetry Observations And Hydrodynamic Models, Sabrina Desoto

Electronic Theses and Dissertations

Supernovae (SNe) are the energetic deaths of massive stars, dispersing heavy elements throughout the galaxies and shaping cosmic evolution across the universe. However, understanding the connections between the evolution of massive stars, their catastrophic demises, and the myriad of observed SNe, remains a fundamental challenge in astrophysics. My work aims to narrow this gap by integrating extensive observational data with advanced hydrodynamical simulations to better interpret SNe observations and understand the origin of their geometry. The observational component utilizes the largest spectropolarimetry dataset of stripped-envelope (SE) core-collapse supernovae (CCSNe) gathered by the SNSPOL project. Analyzing nine Type Ib and eleven …

Converging On The Cepheid Metallicity Dependence: Implications Of Nonstandard Gaia Parallax Recalibration On Distance Measures, Louise Breuval, Gagandeep S. Anand, Richard I. Anderson, Rachael Beaton, Anupam Bhardwaj, Stefano Casertano, Gisella Clementini, Mauricio Cruz Reyes, Giulia De Somma, Lucas M. Macri

Physics & Astronomy Faculty Publications

By comparing Cepheid brightnesses with geometric distance measures including Gaia EDR3 parallaxes, most recent analyses conclude metal-rich Cepheids are brighter, quantified as γ ∼ −0.2 mag dex−1 . While the value of γ has little impact on the determination of the Hubble constant in contemporary distance ladders (due to the similarity of metallicity across these ladders), γ plays a role in gauging the distances to metal-poor dwarf galaxies like the Magellanic Clouds and is of considerable interest in testing stellar models. Recently, B. F. Madore & W. L. Freedman (hereafter MF25) recalibrated Gaia EDR3 parallaxes by adding to them a …

Synthesis And Characterization Of Highly Stable Fisetin Encapsulated In Lecithin-Chitosan-Savie Nanoparticles, Hart Monyatovsky, Travis Anderson, Jay Nadeau

Physics Faculty Publications and Presentations

Senolytic drugs, of the class of polyphenolic flavonoids, have attracted attention for a wide variety of medical applications for which they may be delivered topically, orally, and/or intravenously. However, due to their hydrophobicity and sensitivity to light and oxygen, they have been proven difficult to package and deliver. Here we report a synthesis method for encapsulated fisetin using lecithin-chitosan ionic gelation with a recently reported surfactant that is an alternative to polyethylene glycol (PEG)-containing compounds. Called “Savie” for a contraction of its components, sarcosine-Vitamin E, this surfactant allows for production of sub-100 nm nanoparticles that are bench stable for at …

Likelihoods For Stochastic Gravitational Wave Background Data Analysis, Gabriele Franciolini, Mauro Pieroni, Angelo Ricciardone, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present a systematic study of likelihood functions used for stochastic gravitational wave background (SGWB) searches. By dividing the data into many short segments, one customarily takes advantage of the central limit theorem to justify a Gaussian cross-correlation likelihood. We show, with a hierarchy of ever more realistic examples—beginning with a single frequency bin and one detector, and then moving to two and three detectors with white and colored signal and noise—that approximating the exact Whittle likelihood by various Gaussian alternatives can induce systematic biases in the estimation of the SGWB parameters. We derive several approximations for the full likelihood …