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Optical Investigation Of A Low-Pressure Plasma In A Superconducting Radio-Frequency Cavity, Zachary A. Caudell Oct 2024

Optical Investigation Of A Low-Pressure Plasma In A Superconducting Radio-Frequency Cavity, Zachary A. Caudell

Electrical & Computer Engineering Theses & Dissertations

The state-of-the-art cryomodules for particle accelerators use superconducting radio-frequency (SRF) cavities. It is known that accumulation of hydrocarbon impurities reduces the cavity surface work function, decreasing cryomodule performance metrics such as field emission, thermal stability, and accelerating gradients. An in-situ method of plasma processing has recently been developed to clean the cavities and restore cryomodule performance [1]. This study is to understand the properties of the low-pressure plasmas generated in a C100 SRF cavity and ultimately to improve the performance of plasma surface cleaning using optical emission spectroscopy. Using a 500 mm focal length Czerny-Turner monochromator coupled with a photomultiplier …


Comparative Analysis In The Effectiveness Of Real Vs. Virtual Labs In Enhancing Students’ Conceptual Understanding Of Archimedes’ Principle, Judeanto Edy, Sutopo Sutopo, Edi Supriana Sep 2024

Comparative Analysis In The Effectiveness Of Real Vs. Virtual Labs In Enhancing Students’ Conceptual Understanding Of Archimedes’ Principle, Judeanto Edy, Sutopo Sutopo, Edi Supriana

Jurnal Pendidikan Sains

This research aimed to investigate the effectiveness of virtual laboratories compared to real laboratories in improving students’ conceptual understanding of Archimedes’ principle. A quantitative approach was employed using a pretest-posttest design. The measurement instrument used in this study was a concept mastery test, consisting of 15 multiple-choice questions. Data were analyzed using an independent sample T-test. The research involved students from two XI IPA classes, each consisting of 33 students. The findings indicated that both virtual and real laboratories in the learning process could enhance students’ conceptual understanding. The study concluded that there was no significant difference between the virtual …


Design, Characterization, And Simulation Of A 2d Dual-Rail Quantum Processor, Diego Barrutia Sep 2024

Design, Characterization, And Simulation Of A 2d Dual-Rail Quantum Processor, Diego Barrutia

Dartmouth College Master’s Theses

Bosonic systems, such as three-dimensional (3D) λ/4 coaxial cavities and two-dimensional (2D) λ/2 coplanar waveguide (CPW) resonators, are quantum harmonic oscillators that encode information in phase space, offering a hardware-efficient route toward quantum error correction and simulation in superconducting circuits. In this thesis, we present the design, characterization, and simulation of a dual-rail processor constructed with a 2D λ/2 coplanar waveguide resonators, demonstrating a percent error between experimental and analytical results within a range of 3.31% - 13.16%. The analytical results exhibit high precision but lower accuracy relative to experimental measurements. By integrating both closed-source and open-source software tools, we …


Search For Photons Above 1018 Ev By Simultaneously Measuring The Atmospheric Depth And The Muon Content Of Air Showers At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, N. Nguyen, D. Nitz Sep 2024

Search For Photons Above 1018 Ev By Simultaneously Measuring The Atmospheric Depth And The Muon Content Of Air Showers At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, N. Nguyen, D. Nitz

Michigan Tech Publications

The Pierre Auger Observatory is the most sensitive instrument to detect photons with energies above 1017 eV. It measures extensive air showers generated by ultrahigh energy cosmic rays using a hybrid technique that exploits the combination of a fluorescence detector with a ground array of particle detectors. The signatures of a photon-induced air shower are a larger atmospheric depth of the shower maximum (Xmax) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced cascades. In this work, a new analysis technique in the energy interval between 1 and 30 …


Settling Of Two Rigidly Connected Spheres, Z. Maches, Morgane Houssais Sep 2024

Settling Of Two Rigidly Connected Spheres, Z. Maches, Morgane Houssais

Physics

Laboratory experiments and particle-resolved simulations are employed to investigate the settling dynamics of a pair of rigidly connected spherical particles of unequal size. They yield a detailed picture of the transient evolution and the terminal values of the aggregate's orientation angle and its settling and drift velocities as functions of the aspect ratio and the Galileo number, which denotes the ratio of buoyancy and viscous forces acting on the aggregate. At low to moderate values of, the aggregate's orientation and velocity converge to their terminal values monotonically, whereas for higher -values the aggregate tends to undergo a more complex motion. …


Search For Core Collapse Supernovae Signals In Ligo’S Third Observation Run Using A Network Of Gravitational Wave Detectors Integrated With A Multiclass Convolutional Neural Network, Shahrear Khan Faisal, Gaukhar Nurbek, Michael Benjamin, Bhawana Sedhai, Soma Mukherjee Sep 2024

Search For Core Collapse Supernovae Signals In Ligo’S Third Observation Run Using A Network Of Gravitational Wave Detectors Integrated With A Multiclass Convolutional Neural Network, Shahrear Khan Faisal, Gaukhar Nurbek, Michael Benjamin, Bhawana Sedhai, Soma Mukherjee

Physics & Astronomy Faculty Publications

In the existing body of literature, numerous waveforms of core collapse supernovae (CCSN) have emerged from extensive simulations conducted in high-performance computing facilities globally. These waveforms exhibit distinct characteristics related to their explosion mechanisms, influenced by parameters such as progenitor mass, angular momentum, gravitational wave energy, peak frequency, duration, and equation of state. Core collapse supernovae stand out as highly anticipated sources in LIGO’s fourth observation (O4) run, prompting dedicated efforts to detect them. The integration of machine learning, specifically convolutional neural networks (CNN), has become a pivotal avenue for analysis. This study addresses a fundamental query: how can a …


Radiotherapy Dose Calculation Algorithm Sensitivity To High-Density Artifacts, Kylie Blue Sep 2024

Radiotherapy Dose Calculation Algorithm Sensitivity To High-Density Artifacts, Kylie Blue

All ETDs from UAB

Radiotherapy planning can be adversely affected by inaccurate dose calculations due to the presence of high-density objects. High-density objects, such as surgical clips, produce artifacts in CT images which can result in errors in dose calculation. Manual correction of voxels containing incorrect information is recommended to prevent calculation errors, but this process can be cumbersome and sometimes results in planners compromising with crude corrections to save time. In this study we aim to determine the significance of small high-density objects and the artifacts they cause in radiotherapy treatment plans. To evaluate the impact of density overrides on calculations, a phantom …


Angular Momentum Flow Without Anything Carrying It, Yakir Aharonov, Daniel Collins, Sandu Popescu Sep 2024

Angular Momentum Flow Without Anything Carrying It, Yakir Aharonov, Daniel Collins, Sandu Popescu

Mathematics, Physics, and Computer Science Faculty Articles and Research

Transfer of conserved quantities between two remote regions is generally assumed to be a rather trivial process: a flux of particles carrying the conserved quantities propagates from one region to another. However, we demonstrate a flow of angular momentum from one region to another across a region of space in which there is a vanishingly small probability of any particles (or fields) being present. This shows that the usual view of how conservation laws work needs to be revisited.


Performance Of The Hawc Observatory And Tev Gamma-Ray Measurements Of The Crab Nebula With Improved Extensive Air Shower Reconstruction Algorithms, A. Albert, R. Alfaro, C. Alvarez, A. Andrés, J. C. Arteaga-Velázquez, D. Avila Rojas, S. Groetsch, P. Hüntemeyer, R. Turner, X. Wang, Et Al. Sep 2024

Performance Of The Hawc Observatory And Tev Gamma-Ray Measurements Of The Crab Nebula With Improved Extensive Air Shower Reconstruction Algorithms, A. Albert, R. Alfaro, C. Alvarez, A. Andrés, J. C. Arteaga-Velázquez, D. Avila Rojas, S. Groetsch, P. Hüntemeyer, R. Turner, X. Wang, Et Al.

Michigan Tech Publications

The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, located on the side of the Sierra Negra volcano in Mexico, has been fully operational since 2015. The HAWC collaboration has recently significantly improved their extensive air shower reconstruction algorithms, which has notably advanced the observatory performance. The energy resolution for primary gamma rays with energies below 1 TeV was improved by including a noise-suppression algorithm. Corrections have also been made to systematic errors in direction fitting related to the detector and shower plane inclinations, O ( 0 .° 1 ) biases in highly inclined showers, and enhancements to the core reconstruction. The …


Luminescent Coupling In Perovskite Tandem Solar Cells: The Advantages Of Perovskite And Luminescent Coupling In Photovoltaics, Briana Dokken Sep 2024

Luminescent Coupling In Perovskite Tandem Solar Cells: The Advantages Of Perovskite And Luminescent Coupling In Photovoltaics, Briana Dokken

Senior Seminars and Capstones

Multijunction or tandem solar cells are made of multiple semiconductor light absorbing layers. Having multiple absorber layers in a solar cell allows it to absorb a larger range of the solar spectrum. When electrons recombine (relax to a lower energy state) in the top layer of a tandem solar cell, they can emit luminescent photons that are absorbed by the bottom layer of the cell. This process is called luminescent coupling, and it can be used to enhance the performance of photovoltaic cells. Another strategy to increase solar cell performance is to use perovskite as the absorber layer material. Currently, …


Relativistic And Recoil Corrections To Vacuum Polarization In Muonic Systems: Three-Photon Exchange, Gauge Invariance, And Numerical Values, Gregory S. Adkins, Ulrich D. Jentschura Sep 2024

Relativistic And Recoil Corrections To Vacuum Polarization In Muonic Systems: Three-Photon Exchange, Gauge Invariance, And Numerical Values, Gregory S. Adkins, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

For an accurate theoretical description of muonic bound systems, it is crucial to consistently treat relativistic and recoil corrections to vacuum polarization. The one-loop vacuum-polarization effect is by far the dominant quantum electrodynamic (QED) energy correction for bound muons, being of order α(Zα)2mr, where α is the fine-structure constant, Z is the nuclear charge number, and mr is the reduced mass. Gauge invariance of the relativistic and recoil corrections to vacuum polarization of order α(Zα)4mr is investigated with respect to nonretarded and standard, renormalized variants of Coulomb gauge. The invariance is shown after including three-photon exchange diagrams. Our derivation is …


Design And Characterization Of De Novo Photoactivated Charge Separating Proteins, Paul M. Molinaro Sep 2024

Design And Characterization Of De Novo Photoactivated Charge Separating Proteins, Paul M. Molinaro

Dissertations, Theses, and Capstone Projects

Light activate charge separation can provide high energy electrons for a variety of chemical processes. Reaction center proteins serve as a scaffold for small molecules that serve as “hopping” sites for electrons. Previous reaction center designs are four helix bundles that bind at minimum two metalloporphyrin’s: a zinc porphyrin serves as a light activated electron donor, mimicking chlorophyl, and a heme molecule serving as the acceptor. The efficiency of these designs is hampered by the enhanced relaxation of the singlet excited state of zinc porphyrin molecules due to spin-orbit coupling with the paramagnetic heme acceptor. The optimal design would contain …


Precision Measurement Of The Absolute Energy Of The 2s3s 1S0 State In Neutral 9Be, K. J. Ahrendsen, T. Karani, W. D. Williams Sep 2024

Precision Measurement Of The Absolute Energy Of The 2s3s 1S0 State In Neutral 9Be, K. J. Ahrendsen, T. Karani, W. D. Williams

Physics: Faculty Publications

We report on the absolute energy of the 2⁢��⁢3⁢��⁢1⁢��0 state in neutral 9Be. In doing so, we measure the transition frequencies of the 2⁢��2⁢1⁢��0→ 2⁢��⁢2⁢��⁢1⁢��∘1 and 2⁢��⁢2⁢��⁢1⁢��∘1→ 2⁢��⁢3⁢��⁢1⁢��0 transitions, also determining the absolute energy of the 2⁢��⁢2⁢��⁢1⁢��∘1 state. The results are obtained from a home-built hollow cathode discharge lamp using saturated absorption spectroscopy with laser frequencies referenced to a frequency comb. The transition frequencies are determined to be 1276080080⁢(50) and 363105650⁢(130) MHz for the 2⁢��2⁢1⁢��0→ 2⁢��⁢2⁢��⁢1⁢��∘1 and 2⁢��⁢2⁢��⁢1⁢��∘1→ 2⁢��⁢3⁢��⁢1⁢��0 transitions, respectively. The absolute energies are determined to be 42565.4498⁢(17) and 54677.350⁢(5) cm−1 for the 2⁢��⁢2⁢��⁢1⁢��∘1 and 2⁢��⁢3⁢��⁢1⁢��0 states, respectively. The …


Strain And Substrate-Induced Electronic Properties Of Novel Mixed Anion-Based 2d Schx2 (X = I/Br) Semiconductors, Ashima Rawat, Ravindra Pandey Sep 2024

Strain And Substrate-Induced Electronic Properties Of Novel Mixed Anion-Based 2d Schx2 (X = I/Br) Semiconductors, Ashima Rawat, Ravindra Pandey

Michigan Tech Publications

Exploration of compounds featuring multiple anions beyond the single-oxide ion, such as oxyhalides and oxyhydrides, offers an avenue for developing materials with the prospect of novel functionality. In this paper, we present the results for a mixed anion layered material, ScHX2 (X: Br, I) based on density functional theory. The result predicted the ScHX2 (X: Br, I) monolayers to be stable and semiconducting. Notably, the electronic and mechanical properties of the ScHX2 monolayers are comparable to well-established 2D materials like graphene and MoS2, rendering them highly suitable for electronic devices. Additionally, these monolayers exhibit an ability to adjust their band …


Imaging Photoinduced Dynamics In Gas-Phase Molecules Using Ultrafast Electron And X-Ray Diffraction, Sri Bhavya Muvva Sep 2024

Imaging Photoinduced Dynamics In Gas-Phase Molecules Using Ultrafast Electron And X-Ray Diffraction, Sri Bhavya Muvva

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

Investigating the ultrafast structural changes in photoexcited molecules provides essential information on their governing reaction mechanisms and product formation. Time-resolved electron and X-ray diffraction are crucial techniques for capturing the structural information of photoexcited molecules on femtosecond timescales. This thesis presents the investigations of photochemical reactions in gas-phase molecules using ultrafast electron and X-ray diffraction experiments.

Photoexcitation of conjugated diene molecules with ultraviolet (UV) laser pulses can lead to different reaction mechanisms, depending on their double bonds’ positions and molecular rigidity. Chapter 2 of this dissertation discusses the femtosecond time-resolved UV-induced excited-state structural dynamics of cis,cis-1,3-cyclooctadiene, an eight-membered cyclic conjugated …


Investigating Temperature And Emissivity Separation Techniques Through The Use Of A Spectral Emissivity Database, Mitchell A. Manzardo Sep 2024

Investigating Temperature And Emissivity Separation Techniques Through The Use Of A Spectral Emissivity Database, Mitchell A. Manzardo

Theses and Dissertations

This study evaluates two temperature and emissivity separation techniques using data from an ABB MR304 FTIR and a Telops Mid-Wave Hyper-Cam on carbon-based samples heated by a high-energy laser. The established Linear Spectral Emissivity Constraint (LSEC) and Gray Body Emissivity (GBE) methods, as well as a new Robust Ratio Linear Fitting (RRF) method are assessed for their applicability in controlled lab environments. A spectral emissivity database aids in analyzing method performance. The RRF method shows promise but has limitations, particularly with low-temperature data and complex Hyper-Cam data. Despite these challenges, the RRF method offers potential for further refinement.


Performance Of The Hawc Observatory And Tev Gamma-Ray Measurements Of The Crab Nebula With Improved Extensive Air Shower Reconstruction Algorithms, A. Albert, R. Alfaro, C. Alvarez, A. Andrés, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, F. Carreón, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, C. De Leon, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, K. Engel, T. Ergin, C. Espinoza, K. L. Fan, K. Fang, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, H. Goksu, M. M. Gonzalez, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernandez-Cadena, I. Herzog, J. Hinton, D. Huang, F. Hueyotl-Zahuantitla, P. Huntemeyer, A. Iriarte, S. Kaufmann, A. Lara, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Montes, E. Moreno, M. Mostafa, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, L. Olivera-Nieto, N. Omodei, M. Osorio-Archila, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, H. Salazar, D. Salazar-Gallegos, A. Sandoval, M. Schneider, G. Schwefer, J. Serna-Franco, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, Xiaojie Wang, I. J. Watson, K. Whitaker, E. Willox, H. Wu, S. Yu, S. Yun-Carcamo, H. Zhou Sep 2024

Performance Of The Hawc Observatory And Tev Gamma-Ray Measurements Of The Crab Nebula With Improved Extensive Air Shower Reconstruction Algorithms, A. Albert, R. Alfaro, C. Alvarez, A. Andrés, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, F. Carreón, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, C. De Leon, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, K. Engel, T. Ergin, C. Espinoza, K. L. Fan, K. Fang, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, H. Goksu, M. M. Gonzalez, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernandez-Cadena, I. Herzog, J. Hinton, D. Huang, F. Hueyotl-Zahuantitla, P. Huntemeyer, A. Iriarte, S. Kaufmann, A. Lara, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Montes, E. Moreno, M. Mostafa, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, L. Olivera-Nieto, N. Omodei, M. Osorio-Archila, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, H. Salazar, D. Salazar-Gallegos, A. Sandoval, M. Schneider, G. Schwefer, J. Serna-Franco, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, Xiaojie Wang, I. J. Watson, K. Whitaker, E. Willox, H. Wu, S. Yu, S. Yun-Carcamo, H. Zhou

Physics Faculty Research & Creative Works

The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, located on the side of the Sierra Negra volcano in Mexico, has been fully operational since 2015. The HAWC collaboration has recently significantly improved their extensive air shower reconstruction algorithms, which has notably advanced the observatory performance. The energy resolution for primary gamma rays with energies below 1 TeV was improved by including a noise-suppression algorithm. Corrections have also been made to systematic errors in direction fitting related to the detector and shower plane inclinations, O ( 0 .° 1 ) biases in highly inclined showers, and enhancements to the core reconstruction. The …


Reexamination Of Vacuum-Polarization Corrections To The Self-Energy In Muonic Bound Systems, B. Ohayon, Ulrich D. Jentschura Sep 2024

Reexamination Of Vacuum-Polarization Corrections To The Self-Energy In Muonic Bound Systems, B. Ohayon, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

In muonic bound systems, the dominant radiative correction is due to vacuum polarization. Yet, for the interpretation of precision experiments, self-energy effects are also important. In turn, additional vacuum-polarization loops perturb the self-energy. Here we show that combined self-energy vacuum-polarization effects can perturb the bound-state self-energy at the percent level in one-muon bound systems with nuclear charges Z=1-6. We also update previous treatments of the corrections for muonic hydrogen, muonic deuterium, and muonic helium bound systems.


Collisional And Spatial Characterization Of Electron Broadening In Rubidium Vapor, Jordan C. Mindrup Sep 2024

Collisional And Spatial Characterization Of Electron Broadening In Rubidium Vapor, Jordan C. Mindrup

Theses and Dissertations

Stark broadening of the 42D → 122F transition of rubidium is examined in a rubidium vapor cell with modulated double pump-probe spectroscopy at helium pressures of 0.001 Torr, 3.0 Torr, and 30.0 Torr. A pressure dependent critical rubidium number density was observed after which the presence of electrons becomes dominant. It is observed that after the rubidium density threshold, a linear relationship is seen between rubidium number density and the Stark broadened width of the line shapes, with a slope of 0.079 ± 0.002, 0.18 ± 0.01, and 0.9 ± 0.1 for helium pressures of 0.001 …


Design, Fabrication, And Spectroscopy Of Photocatalytic Materials In Visible Spectrum, Yamuna Paudel Sep 2024

Design, Fabrication, And Spectroscopy Of Photocatalytic Materials In Visible Spectrum, Yamuna Paudel

Dissertations, Theses, and Capstone Projects

Heterogeneous photocatalysis has attracted research interest in sustainable energy technologies. However, achieving high photocatalytic efficiency from visible light-absorbing semiconductors is challenging due to their weak absorption, transport losses, and low activity. While multilayer approaches have been developed to enhance the surface reactivity and stability independent of electronic factors, a comprehensive framework for optimizing light-matter interactions has not yet been established. Here, we introduce a photonic strategy using semiconductor metasurfaces, which is highly effective in enhancing the photocatalytic activity of GaAs, a high-performance semiconductor with a near-infrared bandgap. Our engineered pillar arrays with heights of ~150 nm exhibit Mie resonances near …


Interplay Of Magnetic Impurities And Superconductivity In Topological Materials, Didier Ndengeyintwali Sep 2024

Interplay Of Magnetic Impurities And Superconductivity In Topological Materials, Didier Ndengeyintwali

Dissertations, Theses, and Capstone Projects

The interplay of superconductivity and magnetism has been a long-standing topic of interest since the discovery of superconductivity. In recent years it has been shown that topological superconductivity, which has promising applications such as in topological quantum computing, could result from such interplay. Motivated by the later results I study the effect of magnetic impurities in superconducting doped topological insulators, such as Iron based topological superconductors. I show that topological character of parent materials could lead to modifications in the structure of magnetic impurity induced in-gap states. Moreover, the superconductivity induced interaction between magnetic impurities in doped topological insulator would …


Shear Viscosity Of Quasi One-Dimensional Bec Tubes And Entanglement Negativity Conditions, Camilla Polvara Sep 2024

Shear Viscosity Of Quasi One-Dimensional Bec Tubes And Entanglement Negativity Conditions, Camilla Polvara

Dissertations, Theses, and Capstone Projects

Shear Viscosity of Quasi One-dimensional BEC Tubes

We consider layered Bose-Einstein condensates interacting via contact intra-condensate interacions and dipolar inter-condensate potentials, both of which dominate intercondensate tunneling (which we neglect for simplicity). For this system, we compute the normal modes, we study its localization properties by numerically computing the inverse participation ratio, and we compute the inter-tube shear viscosity.

Entanglement Negativity Conditions

This project explores bounds on entanglement negativity using operator inequalities, building on the results of [1]. We are looking for a way to quantify entanglement, as an alternative to calculating the full negativity, which would otherwise require the …


Mg3sb2-Based Materials For Mid-Temperature Thermoelectric Application, Veera Prabhu K Aug 2024

Mg3sb2-Based Materials For Mid-Temperature Thermoelectric Application, Veera Prabhu K

Theses and Dissertations

Recently, there has been growing research in the scientific community regarding the conversion of heat flux into electricity, which has proven effective in mitigating energy crises. Solid-state thermoelectric (TE) devices use the Seebeck effect to efficiently convert waste heat into electricity. Traditional materials contain toxic, rare, and expensive elements like Lead, Tellurium, and Germanium that restrict large-scale production, commercialization, and practical utilization.

Recently, Mg3Sb2-based materials have been attractive due to their remarkable characteristics, including abundance, affordability, and environmental friendliness. Furthermore,n-type Mg3Sb2-based materials exhibit high TE performance because of their high band degeneracy in the conduction band minimum (CBM), and low …


Emergence Of Extreme Events In Nonlinear Oscillators Due To Parametric And External Excitations, Kaviya B Aug 2024

Emergence Of Extreme Events In Nonlinear Oscillators Due To Parametric And External Excitations, Kaviya B

Theses and Dissertations

This comprehensive PhD thesis immerses itself in the intricate world of dynamical systems, aiming to understand, characterize, and develop innovative mitigation strategies for rare and extreme events occurring within diverse nonlinear oscillatory models. The term "events" spans a broad array of occurrences within defined systems, with "rare events" standing out as infrequent outliers or deviations from the norm.

Rare events span various disciplines such as oceanography, climate studies, biology, economics, ecology, encompassing phenomena like rogue waves, floods, cyclones, earthquakes, and financial crises. Recognized for their potential to cause substantial harm to both society and the environment, these events are widely …


Antioxidant, Photoprotective, And Cytotoxic Activities Of Tristaniopsis Merguensis Leaf Fractions With Molecular Docking Study Of Potential Fraction, Boima Situmeang, Respati Tri Swasono, Tri Joko Raharjo Aug 2024

Antioxidant, Photoprotective, And Cytotoxic Activities Of Tristaniopsis Merguensis Leaf Fractions With Molecular Docking Study Of Potential Fraction, Boima Situmeang, Respati Tri Swasono, Tri Joko Raharjo

Karbala International Journal of Modern Science

Through experimental along with molecular docking techniques of potential fraction, this study intended to evaluate the essential phytochemical elements of Tristaniopsis merguensis leaflets as well as potential antioxidant, photoprotective, along with cytotoxic activities. The DPPH and ABTS tests were used to evaluate the antioxidant efficacy of the n-hexane (HPF), ethyl acetate (EPF), and methanol (MPF) fractions. Using an in-vitro solar protection factor (SPF) assessment, the photoprotective ability of T. merguensis components against UV damage was examined. Subsequently, invitro cytotoxic research were carried out against MCF-7 cell line (breast cancer line) assay. This was followed by molecular docking stimulation testing against …


On The Formation And Detectability Of H2Cncn And Its Progenitors, Ryan C. Fortenberry, Vincent J. Esposito Aug 2024

On The Formation And Detectability Of H2Cncn And Its Progenitors, Ryan C. Fortenberry, Vincent J. Esposito

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

New highly exothermic formation pathways incorporating both thermodynamic and kinetic control for the newly astronomically detected H2CNCN molecule are paired with extremely accurate quantum chemical rovibrational spectroscopic computations. The reactions between astronomically known CH2CN/CH2CCH + HNCN follow effectively identical pathways and proceed through stable intermediates and over deeply submerged transition states to form H2CNCN and HCN/HCCH coproducts. Similarly, the reaction between CHM2CN and NCN− can also form H2CNCN, although this pathway first requires the initial formation of NCN−, which is currently undetected in space, via …


Dynamical Dark Energy From Lattice Quantum Gravity, Mingwei Dai Aug 2024

Dynamical Dark Energy From Lattice Quantum Gravity, Mingwei Dai

Dissertations - ALL

We study various topics of Euclidean dynamical triangulations (EDT). We study the interaction of two scalar particles, and show that in the appropriate limit we recover an interaction compatible with Newton's gravitational potential in four dimensions. Working in the quenched approximation, we calculate the binding energy of a two-particle bound state, and study its dependence on the constituent particle mass in the non-relativistic limit. We find a binding energy compatible with the ground state energy by solving the Schr\"{o}dinger equation for Newton's potential. This allows us to determine the lattice spacing in EDT for the first time, and we find …


Open Quantum Systems In High Energy Physics, Bharath Sambasivam Aug 2024

Open Quantum Systems In High Energy Physics, Bharath Sambasivam

Dissertations - ALL

Open quantum systems (OQS) are ubiquitous in various fields of physics, such as high energy physics, cosmology, atomic and molecular physics, and quantum optics. In some cases, there is a natural separation between the system and the environment, like the presence of a horizon in inflationary cosmology. In other cases, like field theories coupled to thermal baths or at finite chemical potential, it is not practical to simulate the large number of degrees of freedom making up the bath. The system of interest can be described by an effective theory upon integrating out the environment degrees of freedom. In certain …


Studies Towards Improved Gravitational Wave Detector Thermodynamics, Daniel Vander-Hyde Aug 2024

Studies Towards Improved Gravitational Wave Detector Thermodynamics, Daniel Vander-Hyde

Dissertations - ALL

Since the first gravitational wave detection, the Laser Interferometric Gravitational Wave Observatories (LIGO) combined with an expanding and co-observing global gravitational wave network (i.e. Virgo, KAGRA) has worked to increase a novel and growing astronomical data catalog of gravitational wave detections. With each additional observing run, rates of detection continue to increase with iterative upgrades to detector technology. Discussed within this thesis are considerations pertinent to the improvement of Dual Recycled Fabry-Perot Michelson interferometer (DRFPMI) thermodynamics proposed during LIGO's third observing run (O3) for present and future detectors. The first chapter reviews fundamental material relevant to gravitational waves and how …


Ultralight Vector Dark Matter Search Using Data From The Kagra O3gk Run, A. Abac, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang Aug 2024

Ultralight Vector Dark Matter Search Using Data From The Kagra O3gk Run, A. Abac, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the …