Digital Commons Network^™

Understanding The Growth Mechanism Of Thiol-Conjugated Au25 Cluster, Chunhui Liu, Haiying He, Ravindra Pandey, Shashi P. Karna

Michigan Tech Publications

The synthesis of ligand-conjugated gold nanoclusters has attracted significant attention due to its ability to achieve precise control over cluster size selectivity. Among these, Au₂₅(SR)₁₈-, where R represents an alkyl group, is one of the earliest being synthesized with a very high yield, although its growth mechanism is yet to be fully understood. Using density functional theory, we present the results of a theoretical investigation on the growth process of Au₂₅(SR)₁₈-, beginning from Au₁₃(SR)₁₂-. Our findings indicate that the sulfur atoms in the core structure of Au_{13 …}

Radiative Energy And Mass Shifts Of Quantum Cyclotron States, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Abstract: We discuss relativistic and radiative corrections to the energies of quantum cyclotron states. In particular, it is shown analytically that the leading logarithmic radiative (self-energy) correction to the bound-state energy levels of quantum cyclotron states is state independent and must be interpreted as a magnetic field-dependent correction to the electron's mass in a Penning trap.

Contaminated Sweeping Langmuir Probes On Sounding Rocket Platforms, Rachel Conway

Doctoral Dissertations and Master's Theses

Sweeping Langmuir Probes (SLPs) are one of the most commonly used probes on sounding rocket missions. They offer measurements of plasma density, electron temperature, and both relative and absolute payload charging. One of the major implementation challenges, however, is contamination on the surface of the probe such that collected IV curves become distorted. This distortion can result in deflated densities, inflated temperatures, and erroneous charging measurements. This dissertation aims to expand our understanding of contamination's impact on SLP data and offer new mitigation methods appropriate for the sounding rocket platform.

SPICE, Simulation Program with Integrated Circuit Emphasis, is used to …

Developing Fixed-Bias Langmuir Probes For Multi-Point Constellation Deployments, Henry Carter Valentine

Doctoral Dissertations and Master's Theses

Since their initial development in the early 20th century, electrostatic Langmuir probes have proved invaluable in terrestrial and interplanetary ionospheric sounding applications. When deployed aboard rocket and satellite platforms, these probes yield high-cadence, in-situ measurements of key plasma parameters such as electron density, ion density, and electron temperature. Furthermore, the efficacy of Langmuir probes in characterizing the three-dimensional structure and dynamics of ionospheric plasmas can be augmented by the technique of multi-payload deployments. In this work, we discuss the design, development, and analysis of fixed-bias Langmuir probes constructed for two multi-point science campaigns: the Mars-bound, dual-satellite Escape and Plasma Acceleration …

Phases And Dynamics Of Quantum Droplets In The Crossover To Two-Dimensions, Jose Carlos Pelayo, George Bougas, Thomás Fogarty, Thomas Busch, Simeon I. Mistakidis

Physics Faculty Research & Creative Works

We explore the ground states and dynamics of ultracold atomic droplets in the crossover region from three to two dimensions by solving the two-dimensional and the quasi-two-dimensional extended Gross-Pitaevskii equations numerically and with a variational approach. By systematically comparing the droplet properties, we determine the validity regions of the pure two-dimensional description, and therefore the dominance of the logarithmic nonlinear coupling, as a function of the sign of the averaged mean-field interactions and the size of the transverse confinement. One of our main findings is that droplets become substantially extended upon transitioning from negative-to-positive averaged mean-field interactions. This is accompanied …

19ne Excited States In Explosive Nucleosynthesis, Khang Pham

LSU Doctoral Dissertations

Classical novae and Type I X-ray bursts are stellar explosions that occur in binary systems, where nuclear reactions involving ¹⁹Ne play a crucial role in nucleosynthesis. In novae, the destruction of ¹⁸F via the ¹⁸F(p,alpha)¹⁵O reaction significantly affects the amount of ¹⁸F remaining in the ejecta, directly influencing the detectability of predicted 511-keV gamma rays. However, discrepancies between observed and predicted ¹⁸F abundances highlight uncertainties in the reaction rates, primarily due to unknown properties of resonances in the compound nucleus ¹⁹Ne. In Type I X-ray bursts, the ¹⁵O(alpha,gamma)¹⁹Ne reaction …

Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs

Senior Honors Papers / Undergraduate Theses

The observation of axions could revolutionize the world of physics. Through microwave frequency cavity readout of the photons associated with these axions, the ADMX project at WashU utilizes multiple different forms of the Josephson junction (JJ), a superconductive circuit element. The physics behind the JJ are essential to understanding its operation for resonant cavity readout in addition to parametric amplification. Parametric amplifiers produced using JJs can approach the signal-to-noise ratio set by quantum mechanics, and prove essential for the amplification chain used by the ADMX experiment for axionic detection. The limits of these amplifiers are set by the noise tuning …

Streamer Discharge Simulation For Plasma-Assisted Combustion, Stuart Jairo Reyes

Electrical & Computer Engineering Theses & Dissertations

A common and successful method to achieve atmospheric pressure fuel-air plasma-assisted combustion is through repetitive ns pulsed discharges and dielectric-barrier discharge. The transient phase in these discharges is dominated by transport influenced by strong space charges produced by ionization fronts, this can be best represented by the streamer model. The function of non-thermal plasma in these discharges is to excite the species in the fuel-air mixture to produce radicals which accelerate the chemical conversion reactions which directly lead to temperature rise, ultimately culminating in ignition. Therefore, the characterization of the streamer and its energy partitioning is essential to developing a …

Synchrotron Radiation Interferometry At Cebaf, Sankalp Rajendra Shinde

Physics Theses & Dissertations

Synchrotron radiation interferometry is a method to measure transverse beam size in electron accelerators. By using synchrotron radiation interferometry at a dispersive location in CEBAF at Jefferson Lab, we measure the electron beam size and energy spread. This interferometry technique allows us to monitor the energy spread non-invasively, to measure precise electron beam rms energy spread for hypernuclear experiments, and verify that they meet experiment requirements in real time. This dissertation discusses the design, simulations, construction, and commissioning of this Synchrotron Radiation Interferometer (SRI) in the Hall C line at Jefferson Lab in 2024–2025.

The Structure Function Of The Free Neutron At High X-Bjorken, Madhusudhan Pokhrel

Physics Theses & Dissertations

Understanding the internal structure of nucleons is one of the primary goals of nuclear physicists. As protons and neutrons are only the bound state solution of the QCD lagrangian (at least inside atomic nuclei), studying protons and neutrons helps uncover nuclear structure. Due to its easy availability, many studies on protons have been done on a wide range of kinematics. However, free neutron targets are not readily achievable. So, any information on neutrons has to be extracted from neutron-rich nuclei, and some nuclear models have to be used to subtract the contributions from other nucleons to extract the information …

Optical Spring Tracking For Enhancing Quantum-Limited Interferometers, Scott M. Aronson

LSU Doctoral Dissertations

Gravitational waves were first predicted by Albert Einstein in 1916. Calculations in the 1970s by Rainer Weiss showed an interferometer of sufficient size could realistically detect gravitational waves, which led to a grant by the National Science Foundation (NSF). With steady progress and over decades of funding by the NSF, the construction of two full scale 4km interferometers was approved and began construction in 1994. This project, coined LIGO the Laser Interferometer Gravitational-wave Observatory, came to be a worldwide collaboration of scientists dedicated to the discovery and study of gravitational waves. In 2015, both LIGO detectors detected a coincident inspiral …

Improving Students’ Understanding And Representational Fluency Of Kinematics Through Learning Cycle 5e With Multi Representational Approach, Magfira Cindy Dianningrum, Enio Kang Mohd Sufian

Jurnal Pendidikan Sains

The use of various forms of representation is believed to help students understand the concept of kinematics better. This research aims to determine the increase in students' conceptual understanding and representational fluency in the kinematics of straight motion through Learning Cycle 5E with multi representational approach on 32 class XI students of State High Schools in Malang. Students' conceptual understanding is assessed with seventeen reasoned multiple choice questions, while representational fluency are assessed with five essay questions. Based on the results of the analysis, students' conceptual understanding and representation abilities increase through the learning carried out. Increased understanding of concepts …

Electrostatics Conceptual Test (Ect) As An Assessment Instrument For Undergraduate Student’S Conceptual Mastery On Static Electricity, Rizqiatul Hasanah, Arif Hidayat, Sutopo Sutopo, Sahal Fawaiz

Jurnal Pendidikan Sains

This study aims to develop an assessment instrument for student mastery of the concept of static electricity, the "Electrostatics Conceptual Test (ECT)." The approach used in this study is research and development (R&D) using the ADDIE model. Expert validation and trial results have led to revisions in this instrument. The results of the final analysis of this instrument show a Cronbach alpha value of 0.702, which indicates that the reliability of the instrument is in the excellent category. We also tested this instrument for external validity, and the results confirm the validity of its 16 items. Before studying static electricity, …

Robust Spacecraft Autonomy For Deep Space Exploration In Special Euclidean Group Se(3), Matthew Wittal

Doctoral Dissertations and Master's Theses

Over the past half-century, humanity has gained extensive experience conducting manned spaceflight near Earth. Arguably, "near Earth" could even include the Moon — the most distant destination humans have reached. However, "near" in this work primarily refers low Earth orbit (LEO). One could argue that we have not truly left Earth since the Apollo, as spacecraft in some LEOs remain subject to atmospheric drag thus emphasizing their continued connection to Earth's immediate environment. Reflecting on this, it becomes clear that humanity has largely remained bound to Earth’s immediate vicinity since the Apollo missions reached the Moon. However, that is set …

Generic Transverse Stability Of Kink Structures In Atomic And Optical Nonlinear Media With Competing Attractive And Repulsive Interactions, S. I. Mistakidis, G. Bougas, G. C. Katsimiga, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We demonstrate the existence and stability of one-dimensional (1D) topological kink configurations immersed in higher-dimensional bosonic gases and nonlinear optical setups. Our analysis pertains, in particular, to the two- and three-dimensional extended Gross-Pitaevskii models with quantum fluctuations describing droplet-bearing environments but also to the two-dimensional cubic-quintic nonlinear Schrödinger equation containing higher-order corrections to the nonlinear refractive index. Contrary to the generic dark soliton transverse instability, the kink structures are generically robust under the interplay of low-amplitude attractive and high-amplitude repulsive interactions. A quasi-1D effective potential picture dictates the existence of these defects, while their stability is obtained numerically and analytically …

Artificially Intelligent Maxwell's Demon For Optimal Control Of Open Quantum Systems, Paolo A. Erdman, Robert Czupryniak, Bibek Bhandari, Andrew N. Jordan, Frank Noé, Jens Eisert, Giacomo Guarnieri

Mathematics, Physics, and Computer Science Faculty Articles and Research

Feedback control of open quantum systems is of fundamental importance for practical applications in various contexts, ranging from quantum computation to quantum error correction and quantum metrology. Its use in the context of thermodynamics further enables the study of the interplay between information and energy. However, deriving optimal feedback control strategies is highly challenging, as it involves the optimal control of open quantum systems, the stochastic nature of quantum measurement, and the inclusion of policies that maximize a long-term time- and trajectory-averaged goal. In this work, we employ a reinforcement learning approach to automate and capture the role of a …

The Impact Of Solar Angle And Cloud Shadows On 3d Reconstruction Of Rolling Stock Cargo, Carlina M. Ostrand, Adam D. Reiman, Frank W. Ciarallo, Scott L. Nykl, Clark N. Taylor, Joshua F. Krutz

Faculty Publications

Meeting the relentless demand for more efficient air cargo transportation is of paramount importance for commercial needs and military missions. This study describes an experiment to test an innovative approach that harnesses cutting-edge stereoscopic vision technology to create 3D point clouds of rolling stock cargo across varying solar angles and cloud shadow conditions. Virtual cargo point clouds are generated by calibrating and systematically organizing the depth and location points from an RGB-D camera and then reprojecting them in a virtual environment. Measurement accuracy was rigorously tested across six camera positions in various combinations of weather conditions against physical ground truth …

Local Structure Of Zinc-Indium-Tin Oxide Films Via Grazing-Incidence X-Ray Pair-Distribution Functions And Theoretical Methods, G. B. González, C. J. Benmore, Julia E. Medvedeva, J. S. Okasinski, C. Riegger, O. Medina, M. M. Stulajter, T. Bsaibes, G. Cardenas, S. Cone, K. Edlund, M. Osorio, T. Holmes, I. Zhuravlev

Physics Faculty Research & Creative Works

A detailed experimental and theoretical study on the local (r ≤ 4.5 Å) atomic structure of amorphous and crystalline zinc-indium-tin oxide (ZITO) thin films using grazing-incidence x-ray Pair-Distribution Functions (PDFs), ab initio Molecular Dynamics (MD), and Empirical Potential Structure Refinement (EPSR) Monte Carlo simulations is presented. High-energy synchrotron x rays, a two-dimensional detector, and different incident angles were used to probe the depth uniformity of five (ZnO)0.15 (In2O3)0.70 (SnO2)0.15 films that were deposited via pulsed-laser deposition at growth temperatures (TG) ranging from 25 to 300 °C. Films deposited at TG ≤ 150 °C were amorphous. The partially crystalline (TG = …

Identification Of Candidate Ultraviolet Counterparts To Globular Cluster X-Ray Binaries, William Schuster

College of Science and Health Theses and Dissertations

X-ray binaries function as sources of potential energy that keep globular clusters from collapsing in on themselves, and therefore, understanding X-ray binaries is crucial to understanding globular clusters, and our galaxy as a whole. The dense cores of globular clusters can prevent both optical photometry and infrared photometry from adequately measuring the brightness of individual stars. However, the cores of globular clusters are much less crowded in the ultraviolet, which allows for the identification of individual stars within the core. By identifying ultraviolet counterparts to each X-ray source within a globular cluster, the type of X-ray emitter can be determined. …

Evidence Of Substorm-Driven Penetration Electric Field Contributions To Low-Latitude Phenomena: Enhanced Upward Drifts, Plasma Bubble Development And Severe Scintillation, J. Sousasantos, F. S. Rodrigues, B. G. Fejer, R. W. Eastes, A. O. Moraes

All Physics Faculty Publications

In this work, it is demonstrated that substorm-driven penetration electric fields can efficiently enhance the upward plasma transport, favoring the development and structuring of plasma irregularities and the occurrence of scintillation on L-band signals. While most previous studies focus on investigating penetration electric fields during intense geomagnetic storms, here, the period used (April 01–05, 2020) was under very mild geomagnetic activity (−27 nT ≤ SYM-H ≤ 6 nT), so that interplanetary and disturbance dynamo contributions are minimized. This period comprised the same seasonal and solar flux conditions, while undergoing multiple short-lived substorms, making it well-suited to evaluate unequivocally: (a) to …

Comprehensive Review On The Application Of Bio-Immunoinformatics In The Development Of Highly Ef-Fective New Candidate Vaccines Against Tuberculosis, Ahyar Ahmad, Andriansjah Rukmana, Miski A. Khairinisa, Dian A. E. Pitaloka, Rosana Agus, Rusdina B. Ladju, Tarwadi Ahmad, Astutiati Nurhasanah, Carina C. D. Joe, Muhammad N. Massi, Harningsih Karim, Irda Handayani, Siti Roszilawati Binti Ramli

Karbala International Journal of Modern Science

Tuberculosis (TB) remains a significant public health challenge worldwide. Currently, Bacillus Calmette-Guerin (BCG) is the only vaccine available for TB prophylaxis. However, the efficacy of the BCG vaccine against adult pulmonary TB is considered inconsistent. This condition encourages researchers to look for more effective options, such as subunit vaccines. This condition requires the development of a more effective subunit vaccine to protect active TB in productive and adult ages. There is an urgent need for more effective vaccines, as the Bacillus Calmette-Guérin (BCG) vaccine currently available has inconsistent efficacy and is only partially effective in adults. Bio-immunoinformatics, an interdisciplinary field …

Layout-Aware Quantum Circuitry And Algorithmic Extensions To Grover's Algorithm, Ali Al-Bayaty

Dissertations and Theses

Lov K. Grover introduced, in 1996, Grover's algorithm as a quantum search algorithm to find all solutions for quantum oracles representing classical problems. My research observed that the Grover diffusion operator of Grover's algorithm gives wrong solutions when Boolean oracles are designed in some logical structures. Therefore, I invented the new "controlled-diffusion operator" for Boolean oracles as a new approach for Grover's algorithm that always correctly solves the problem of Grover's algorithm.

Another important problem in quantum computing is designing reliable and cost-effective quantum gates using reversible binary logic. In classical logic design, the stage of logic design can be …

On Static Equilibrium State Of An Electron-Positron Pair Interacting By Electrostatic And Magnetic Forces, Polievkt Perov, Natasha Perova-Mello

College of Arts & Sciences Faculty Works

An electron-positron pair can be in static equilibrium where the magnetic torque is zero and the attractive Coulomb’s force between unlike charges and the repelling force between the spin magnetic moments of these two particles balance each other out. An electron-positron pair near the equilibrium position can be modeled as an oscillator consisting of two masses on a spring. The calculations of the equilibrium distance, the effective “electromagnetic spring constant”, and the frequency of oscillations of an electron-positron pair near the equilibrium are presented. The calculations might be useful for the students in their studies of electricity, magnetism, and particle …

Novel Approach To Traveling-Wave-Based Fault Location In Nonhomogeneous Transmission Lines, John Parker Burrell

Master's Theses

Accurate fault location is a critical aspect of power system protection, ensuring grid reliability and minimizing downtime. Traditional traveling-wave-based fault location methods face limitations when applied to nonhomogeneous transmission lines due to the reliance on precise segment velocities and propagation time data. This thesis addresses these challenges by proposing a novel algorithm that leverages historical fault data to estimate segment velocities and refine these estimates as more faults occur. The algorithm was rigorously tested using the digital model of an 11-segment, 65.694 km real overhead transmission line and validated using both simulations and hardware tests using commercially available time-domain protective …

Muon Veto Panel Uniformity Tests At Yale Wright Laboratory For The Cuore And Cupid Experiments And Visualizing Dirac Spinors In The Chiral Basis With The Bloch Sphere, Reagen Neeva Garcia

Physics

This senior project is divided into three sections that describe my path and experiences in under graduate research. The first provides an introduction to the field of particle physics and the search for neutrinoless double beta decay (0νββ) with the Cryogenic Underground Observatory for Rare Events (CUORE) experiment, as well as its upgrade, CUPID (CUORE Upgrade with Particle IDentification). The second section details my contributions to these experiments, including my summer working at Yale’s Wright Laboratory on R&D for the CUPID experiment. In this section I describe my work on the experiment’s muon veto system and on light detector development …

Isotopic Analysis Of Lithium Hydroxide Monohydrate Using Laser-Induced Breakdown Self-Reversal Isotopic Spectrometry (Libris) And Machine Learning, Madison R. Moran

Theses and Dissertations

High-resolution Laser-Induced Breakdown Self-Reversal Isotopic Spectrometry (LIBRIS) is implemented to record the 15.8 pm Li I 670.8 nm isotopic shift in LiOH · H₂O samples of varying 6, 7Li abundance. A simple univariate linear regression demonstrates an acquired isotopic shift of 13.813 ± 1.21 pm in samples varying from 3 to 95 ⁶Li at%. Supervised machine learning regressions are trained on self-reversal wavelength locations in order to quantify ⁶Li abundance. A stacked ensemble using two base learners yields the superlative characterization of 6Li abundance with RMSE of 5.66 at% and detection limit of 18.8 at%. Using …

Irreducible Three-Loop Vacuum-Polarization Correction In Muonic Bound Systems, Gregory S. Adkins, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Three-loop electronic vacuum-polarization corrections due to irreducible diagrams are evaluated for two-body muonic ions with nuclear charge numbers 1≤Z≤6. The corrections are of order α3(Zα)2mr, where α is the fine-structure constant and mr is the reduced mass. Numerically, the energy corrections are found to be of the same order of magnitude as the largest of the order α2(Zα)6mr corrections, and are thus phenomenologically interesting. Our method of calculation eliminates numerical uncertainty encountered in other approaches.

Investigation Of Neutron Inelastic Scatter Cross Sections On 16O, Molly A. Wakeling

Theses and Dissertations

Nuclear data underpin a number of applications across nuclear reactor design, medicine, astrophysics, nonproliferation, national security, and other related fields. However, data are conflicting or missing across the spectrum of isotopes and reactions, and theoretical calculations can only go so far to predict nuclear properties. A key reaction with incomplete data is neutron inelastic scatter on ¹⁶O, which reduces neutron energies and produces high-energy gamma rays that are often not taken into account in simulations of nuclear reactors, nuclear weapon detonations, nuclear fusion, and other areas. To fill these gaps, the Gamma-Energy Neutron-Energy Spectrometer for Inelastic Scattering, or GENESIS, …

Atmospheric Characterization For Optical Paths In Lunar Proximity, Patrick D. Carattini

Theses and Dissertations

This paper presents a novel technique for estimating the Fried seeing parameter (r0) for optical paths around the Moon, where traditional methods fail due to the Moon's intensity. Using image processing, it derives the atmospheric optical transfer function (OTF) by using the Moon's edge as a step-input. A simulation chain validates the approach, achieving r0 estimation within 0.0012 m. Real-world tests confirm accuracy through visual and statistical analysis, offering an effective alternative for atmospheric characterization of optical paths close to the moon.

On The Exploration Of Crystallographic Anisotropy And Defects In Shock Loading Using Molecular Dynamics, Benjamin P. Helman

Theses and Dissertations

The impact of crystallographic orientation, grain boundaries, and vacancies on the shock behavior of aluminum was investigated using molecular dynamics simulations. Shock loading in the [001], [011], and [111] directions was explored, revealing anisotropic behavior in shock speed, melting, dislocation density, and unique phase changes. The Hugoniot elastic limit in the [100], [110], and [111] directions was calculated as 23.2 GPa, 24 GPa, and 18.4 GPa respectively. These results were found to be an order of magnitude larger than the compressive yield strength computed at equilibrium. Additionally, metastable melting in the [011] and [111] directions occurred roughly 1000 K below …