Digital Commons Network^™

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 …

Interferometric Differential High-Frequency Lock-In Probe For Laser-Induced Vacuum Birefringence, R. G. Bullis, Ulrich D. Jentschura, D. C. Yost

Physics Faculty Research & Creative Works

We propose a measurement of laser-induced vacuum birefringence through the use of pulsed lasers coupled to femtosecond optical enhancement cavities. This measurement technique features cavity-enhanced pump and probe pulses, as well as an independent control pulse. The control pulse allows for a differential measurement where the final signal is obtained using high-frequency lock-in detection, greatly mitigating time-dependent cavity birefringence as an important and possibly prohibitive systematic effect. In addition, the method features the economical use of laser power and results in a relatively simple experimental setup.

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 …

Tunable Pairing With Local Spin-Dependent Rydberg Molecule Potentials In An Atomic Fermi Superfluid, Chih Chun Chien, Seth T. Rittenhouse, S. I. Mistakidis, H. R. Sadeghpour

Physics Faculty Research & Creative Works

We explore the energy spectrum and eigenstates of two-component atomic Fermi superfluids with tunable pairing interactions in the presence of spin-dependent ultralong-range Rydberg molecule (ULRM) potentials, within the Bogoliubov-de Gennes formalism. The attractive ULRM potentials lead to local-density accumulation, while their difference results in a local polarization potential and induces the in-gap Yu-Shiba-Rusinov (YSR) states whose energies lie below the bulk energy gap. A transition from equal population to population imbalance occurs as the pairing strength falls below a critical value, accompanied by the emergence of local Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-like states characterized by out-of-phase wave functions and lower energies compared to …

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 …

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 …}

The Effects Of Snow Cover On The Dynamic Pressure Of Nuclear Detonation Blast Waves, Adam Card, Andrew W. Decker

Faculty Publications

Blast pressure is the primary military targeting metric for nuclear weapons. Any local conditions that affect blast pressure have the potential for altering nuclear plans, both from defensive and offensive standpoints. Understanding the impact of snow to the blast wave, therefore, provides a benefit both to military planners and to warfighters on the ground, for any operation occurring in arctic environments. No existing data provides a quantitative description of how snow on the ground affects a nuclear detonation blast wave passing over it. Similar blast waves passing over dust have experimentally proven to enhance blast pressure in a localized region.1 …

Microphysics Regimes Due To Haze–Cloud Interactions: Cloud Oscillation And Cloud Collapse, Fan Yang, Hamed F. Sadi, Raymond Shaw, Fabian Hoffmann, Pei Hou, Aaron Wang, Mikhail Ovchinnikov

Michigan Tech Publications

It is known that aqueous haze particles can be activated into cloud droplets in a supersaturated environment. However, haze–cloud interactions have not been fully explored, partly because haze particles are not represented in most cloud-resolving models. Here, we conduct a series of large-eddy simulations (LESs) of a cloud in a convection chamber using a haze-capable Eulerian-based bin microphysics scheme to explore haze–cloud interactions over a wide range of aerosol injection rates. Results show that the cloud is in a slow microphysics regime at low aerosol injection rates, where the cloud responds slowly to an environmental change and droplet deactivation is …

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.

Nanosecond Pulsed Electric Field And Plasma Jets For Cancer Therapy, Edwin Ayobami Oshin

Biomedical Engineering Theses & Dissertations

Nanosecond pulsed electric field (nsPEF) employs nanosecond-duration, high voltage pulses to induce oxidative stress, leading to temporary or permanent damage to cells or tissue (also known as reversible and irreversible electroporation), and has been considered a promising approach for cancer therapy. In parallel to this, nanosecond pulsed atmospheric pressure plasma jets (ns-APPJs) have also shown to be effective in inactivating cancer cells or increasing sensitivity of cells to electric fields. ns-APPJs are known to generate reactive chemical agents, including reactive oxygen and nitrogen species (RONS) which induces oxidative stress resulting in cell proliferation, apoptosis, and necrosis. In this dissertation, a …

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 …

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 …

Influence Of The Impact Parameter For Ionization Of Argon By Fast Positrons And Electrons On The Postcollision Kinematics And Triply Differential Spectra, Robert D. Dubois, K. Tokési

Physics Faculty Research & Creative Works

Classical trajectory Monte Carlo calculations for fast positron and electron impact ionization of argon are used to provide information about how the pre- and post collision kinematics alter the triply differential spectra. It is shown that in addition to the scattering direction expected for a positive or negative projectile passing near a partially screened nuclear charge, scattering in the opposite direction also occurs. Independent of energy transfer, when the impact parameter is less than the mean radius of the 3p electron cloud, the expected direction of scattering always occurs. In contrast, for scattering in the opposite direction, the impact parameter …

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 …

Cryo-Em Captures The Coordination Of Asymmetric Electron Transfer Through A Di-Copper Site In Dpor, Rajnandani Kashyap, Natalie Walsh, Jaigeeth Deveryshetty, Monika Tokmina-Lukaszewska, Kewei Zhao, Yunqiao J. Gan, Brian M. Hoffman, Ritimukta Sarangi, Brian Bothner, Brian Bennett, Edwin Antony

Physics Faculty Research and Publications

Enzymes that catalyze long-range electron transfer (ET) reactions often function as higher order complexes that possess two structurally symmetrical halves. The functional advantages for such an architecture remain a mystery. Using cryoelectron microscopy we capture snapshots of the nitrogenase-like dark-operative protochlorophyllide oxidoreductase (DPOR) during substrate binding and turnover. DPOR catalyzes reduction of the C17 = C18 double bond in protochlorophyllide during the dark chlorophyll biosynthetic pathway. DPOR is composed of electron donor (L-protein) and acceptor (NB-protein) component proteins that transiently form a complex in the presence of ATP to facilitate ET. NB-protein is an α2β2 heterotetramer with two structurally identical …

Measuring Cosmic Rays With Muon Detectors (Quarknet), Aiden Burton, Jack W. Maseberg

SACAD: Scholarly Activities

We report measurement of atmospheric muon particles originating from cosmic rays. Using four QuarkNet project scintillators in an unstacked geometry, we are counting muons in coincidence with each other. We are currently refurbishing a second detector apparatus and will soon be capable of measuring coincidence events for larger shower surface areas using a total of eight scintillators.

Painting Rich Six-Dimensional Pictures Using Polarized Fluorescence Microscopy, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

No abstract provided.

Transient Thermal Energy Harvesting At A Single Temperature Using Nonlinearity, Tamzeed B. Amin, James M. Mangum, Md R. Kabir, Syed M. Rahman, Pradeep Ashaduzzaman, Pradeep Kumar, Luis L. Bonilla, Paul M. Thibado

Physics Faculty Publications and Presentations

The authors present an in-depth theoretical study of two nonlinear circuits capable of transient thermal energy harvesting at one temperature. The first circuit has a storage capacitor and diode connected in series. The second circuit has three storage capacitors, and two diodes arranged for full wave rectification. The authors solve both Ito-Langevin and Fokker-Planck equations for both circuits using a large parameter space including capacitance values and diode quality. Surprisingly, using diodes one can harvest thermal energy at a single temperature by charging capacitors. However, this is a transient phenomenon. In equilibrium, the capacitor charge is zero, and this solution …

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, …

How Do We Observe Relational Observables?, Emily Adlam

Mathematics, Physics, and Computer Science Faculty Articles and Research

In theories with a diffeomorphism symmetry, such as general relativity and canonical quantum gravity, it is often proposed that the empirical content is encoded in relational observables. But how do relational observables actually make contact with experience? I argue that this question can only be answered by providing a schematization of the observer which is appropriate for the context of a diffeomorphism-invariant theory. I suggest that this may require us to move away from a ‘passive awareness’ conception of consciousness towards a more agential conception, because there is a clear sense in which an embodied agent must experience herself as …

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 …

Search For The Anomalous Events Detected By Anita Using The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, K. Nguyen, D. Nitz, Et Al.

Michigan Tech Publications

A dedicated search for upward-going air showers at zenith angles exceeding 110° and energies E>0.1 EeV has been performed using the Fluorescence Detector of the Pierre Auger Observatory. The search is motivated by two "anomalous"radio pulses observed by the ANITA flights I and III that appear inconsistent with the standard model of particle physics. Using simulations of both regular cosmic-ray showers and upward-going events, a selection procedure has been defined to separate potential upward-going candidate events and the corresponding exposure has been calculated in the energy range [0.1-33] EeV. One event has been found in the search period between …

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 …

Exploring Corona Discharge In Electrostatic Printing For Electronics And In Other Application, Zijian Weng

USF Tampa Graduate Theses and Dissertations

The field of printed electronics (PEs) is expanding rapidly, driven by increasing market demand. According to reports, the global market for PEs is expected to reach $23 billion by 2026, with a compound annual growth rate of 18.3% from 2023 to 2028. This growth necessitates the development of innovative printing technologies that can meet these demands efficiently, delivering high-quality, high-resolution PEs suitable for applications in health, environmental monitoring, sports, aerospace, and more.

Currently, PEs manufacturing relies on two main groups of printing technologies. Contact printing methods offer high-speed production but struggle with precision, while non-contact methods provide high resolution but …

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 …

College Of Natural Sciences 2024 Year-End Publication, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 2 Dean's Message
Page 3 Department Highlights
Page 4 One Day for State
Page 5 New Students in Wecota
Page 6-8 Faculty Excellence
Page 9 SDSU Physics Students Recognized
Page 9 Prairie Doc Watch Party
Page 10-11 Student Excellence
Page 11 Connections Abroad
Page 12-13 CNS’s Research Centers
Page 14 Connections Abroad
Page 14 Dean Wolf-Hall Retired
Page 15 Outreach Program
Page 15 Events and Traditions
Page 16 Student Spotlight
Page 17 Alumni Spotlight
Page 18-19 SDSU Alum at Paris Paralympics
Page 20 Work Anniversaries & Programs

Studying The Effect Of The Addition Of Sic Molecules As A Nanocomposite On The Optical Properties Of A Pmma-Ps Blend, Hussein Mejbel Azeez, Marwan Hadi Hussein, Hussein Abosaooda Abbood, Bahaa Hussein Rabee

Makara Journal of Science

In this study, a nanocomposite was prepared using a solution casting technique. The polymer electrolyte blend was formed by combining 0.6 mg of polymethyl methacrylate (PMMA) and 0.4 mg of polystyrene (PS). Subsequently, silicon carbide (SiC) nanoparticles were incorporated into the polymer matrix at varying and precisely measured concentrations. The composite was thoroughly mixed to ensure homogeneity, and Fourier transform infrared spectroscopy spectral analysis confirmed the absence of chemical interactions between the SiC nanoparticles and the polymer components, indicating a physically stable mixture. The above can be reflected in the synthesized compound with new properties, such as semiconductors or semi-insulators. …

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 …