Striatal Beat Frequency Interval Timing Model With Microgravity Stressor, 2024 College of Charleston

#### Striatal Beat Frequency Interval Timing Model With Microgravity Stressor, Jason Michael Fitzgerald, Sorinel Oprisan

*Journal of the South Carolina Academy of Science*

The Striatal Beat Frequency (SBF) model of interval timing uses frontal cortex (FC) neural oscillations to record the state of the brain at the reinforcement time Tc during fixed interval (FI) procedures in the long-term memory (LMEM). The state of the FC oscillators at any given time is stored in a short-term memory (SMEM) buffer. The SBF model uses the spiny neurons of the basal ganglia (BG) as coincidence detectors to produce beats between the content of the SMEM and LMEM. Across multiple species that can perform interval timing, there are two invariant properties: (a) the timing is precise, and …

Luminescent Coupling In Perovskite Tandem Solar Cells: The Advantages Of Perovskite And Luminescent Coupling In Photovoltaics, 2024 University of Minnesota - Morris

#### 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, …

Toi–757 B: An Eccentric Transiting Mini–Neptune On A 17.5–D Orbit, 2024 The University of Texas Rio Grande Valley

#### Toi–757 B: An Eccentric Transiting Mini–Neptune On A 17.5–D Orbit, A Alqasim, N Grieves, N M. Rosário, D Gandolfi, J H. Livingston, S Sousa, K A. Collins, J K. Teske, M Fridlund, Ryan J. Oelkers

*Physics and Astronomy Faculty Publications and Presentations*

We report the spectroscopic confirmation and fundamental properties of TOI 757 b, a mini Neptune on a 17.5 d orbit transiting a bright star ( mag) discovered by the TESS mission. We acquired high precision radial velocity measurements with the HARPS, ESPRESSO, and PFS spectrographs to confirm the planet detection and determine its mass. We also acquired space borne transit photometry with the CHEOPS space telescope to place stronger constraints on the planet radius, supported with ground based LCOGT photometry. WASP and KELT photometry were used to help constrain the stellar rotation period. We also determined the fundamental parameters of …

Electromagnetic Theory And Applications, 2nd Edition, 2024 CUNY City College

#### Electromagnetic Theory And Applications, 2nd Edition, Nicholas Madamopoulos, George Kliros

*Open Educational Resources*

This book intends to provide both the fundamentals of Electromagnetics but also some practical applications of the concepts covered. Having taught electromagnetics for several years, the authors feel that many times the field of electromagnetics comes as “old” and often times students do not appreciate the concepts and their importance in everyday applications. The authors intend to accompany the EM concepts with life applications. Hence, students may see the direct impact of the knowledge they acquire through the study of the field of electromagnetics and better appreciate the field.

Interplay Of Magnetic Impurities And Superconductivity In Topological Materials, 2024 The Graduate Center, City University of New York

#### 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, 2024 The Graduate Center, City University of New York

#### 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 …

Twisted Spatiotemporal Optical Vortex Beams In Dispersive Media, 2024 Air Force Institute of Technology

#### Twisted Spatiotemporal Optical Vortex Beams In Dispersive Media, Milo W. Hyde Iv

*Faculty Publications*

We derive a closed-form expression for the mutual coherence function (MCF) of a twisted spatiotemporal optical vortex (STOV) beam after propagating a distance in a linear dispersive medium. A twisted STOV beam is a partially coherent optical field that possesses a coherent STOV and a stochastic twist coupling its space and time dimensions. These beams belong to a special class of space–time-coupled light fields that carry transverse (to the direction of propagation) orbital angular momentum, making them potentially useful in numerous applications including quantum optics, optical manipulation, and optical communications. After presenting the derivation, we validate our new general MCF …

Reexamination Of Vacuum-Polarization Corrections To The Self-Energy In Muonic Bound Systems, 2024 Missouri University of Science and Technology

#### 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.

Relativistic And Recoil Corrections To Vacuum Polarization In Muonic Systems: Three-Photon Exchange, Gauge Invariance, And Numerical Values, 2024 Missouri University of Science and Technology

#### 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 …

Separation Of Various Higher-Order Effects In The Ionization Of Helium By Proton Impact, 2024 Missouri University of Science and Technology

#### Separation Of Various Higher-Order Effects In The Ionization Of Helium By Proton Impact, S. Majumdar, S. Bastola, A. Hasan, R. Lomsadze, Michael Schulz

*Physics Faculty Research & Creative Works*

We have measured fully differential cross sections (FDCSs) for ionization of helium by 75 keV proton impact. Data were analyzed for electrons ejected into the scattering plane at projectile energy losses well below and above the matching velocity and for scattering angles ranging between 0.1 and 0.5 mrad. Earlier, we observed clear signatures of the post collision interaction (PCI) at the matching velocity; however, in the current data these signatures are completely absent at small energy losses and residues remain at large energy losses. At small energy losses the FDCSs are dominated by non-PCI higher-order effects.

Multiply Differential Study Of Vibrational Dissociative Capture In P+ D2 Collisions, 2024 Missouri University of Science and Technology

#### Multiply Differential Study Of Vibrational Dissociative Capture In P+ D2 Collisions, S. Majumdar, A. Hasan, S. Bastola, B. R. Lamichhane, R. Lomsadze, Michael Schulz

*Physics Faculty Research & Creative Works*

We have measured multiple differential cross sections for dissociative capture in collisions of 75-keV protons with D2. Data were analyzed for kinetic energy releases (KERs) ranging from 0 to 2 eV, where the dissociation is primarily caused by excitation of the nuclear motion to a vibrational continuum state. Pronounced signatures of two-center interference effects were observed. The data were compared to previously published cross sections for dissociative capture in p+H2 collisions, for which we reported a scattering angle dependent phase shift in the interference term. The D2 data reveal qualitative differences in the interference structure to the H2 case. Some …

Stability And Dynamics Of Nonlinear Excitations In A Two-Dimensional Droplet-Bearing Environment, 2024 Missouri University of Science and Technology

#### Stability And Dynamics Of Nonlinear Excitations In A Two-Dimensional Droplet-Bearing Environment, G. Bougas, G. C. Katsimiga, P. G. Kevrekidis, S. I. Mistakidis

*Physics Faculty Research & Creative Works*

We unravel stationary states in the form of dark soliton stripes, bubbles, and kinks embedded in a two-dimensional droplet-bearing setting emulated by an extended Gross-Pitaevskii approach. The existence of these configurations is corroborated through an effectively reduced potential picture demonstrating their concrete parametric regions of existence. The excitation spectra of such configurations are analyzed within the Bogoliubov-de Gennes framework exposing the destabilization of dark soliton stripes and bubbles, while confirming the stability of droplets, and importantly unveiling spectral stability of the kink against transverse excitations. Additionally, a variational approach is constructed providing access to the transverse stability analysis of the …

Strain And Substrate-Induced Electronic Properties Of Novel Mixed Anion-Based 2d Schx2 (X = I/Br) Semiconductors, 2024 Michigan Technological University

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

*Michigan Tech Publications, Part 2*

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 …

A Micromagnetic Study Of Skyrmions In Thin-Film Multilayered Ferromagnetic Materials, 2024 New Jersey Institute of Technology

#### A Micromagnetic Study Of Skyrmions In Thin-Film Multilayered Ferromagnetic Materials, Nicholas J. Dubicki

*Dissertations*

Magnetic skyrmions are topologically protected, localized, nanoscale spin textures in non-centrosymmetric thin ferromagnetic materials and heterostructures. At present they are of great interest to physicists for potential applications in information technology due to their particle-like properties and stability. In a system of multiple thin ferromagnetic layers, the stray field interaction was typically treated with various simplifications and approximations. It is shown that extensive analysis of the micromagnetic equations leads to an exact representation of the stray field interaction energy in the form of layer interaction kernels, a so-called 'finite thickness' representation. This formulation reveals the competition between perpendicular magnetic anisotropy …

Microwave Catalysis-Enabled Membrane Processes For Microbial Inactivation, 2024 New Jersey Institute of Technology

#### Microwave Catalysis-Enabled Membrane Processes For Microbial Inactivation, Fangzhou Liu

*Dissertations*

The COVID-19 pandemic has highlighted the urgent need for advanced technologies to combat virus transmission. Traditional membrane filtration technologies primarily serve as physical barriers, capturing pollutants but failing to inactivate microbial agents such as bacteria and viruses. These membranes typically target larger particles but are ineffective against sub-micrometer viral particles. Thus, there's a critical demand for membrane filtration processes that combine robust filtration with antifouling and reaction -enabled functions for efficient pathogen disinfection. This research explores a novel microwave-assisted membrane filtration process incorporating catalytic reactions to enhance microbial disinfection and prevent membrane fouling, offering a groundbreaking solution to global challenges …

Numerical Techniques For Improving Simulations Of Tropical Cyclones, 2024 New Jersey Institute of Technology

#### Numerical Techniques For Improving Simulations Of Tropical Cyclones, Yassine Tissaoui

*Dissertations*

The increasing frequency and intensity of tropical cyclones (TCs) due to climate change pose significant challenges for forecasting and mitigating their impacts. Despite advancements, accurately predicting TC rapid intensification (RI) remains a challenge. Large eddy simulation (LES) allows for explicitly resolving the large eddies involved in TC turbulence, thus providing an avenue for studying the mechanisms behind their intensification and RI. LES of a full tropical cyclone is very computationally expensive and its accuracy will depend on both explicit and implicit dissipation within an atmospheric model. This dissertation presents two novel numerical methodologies with the potential to improve the efficiency …

Antioxidant, Photoprotective, And Cytotoxic Activities Of Tristaniopsis Merguensis Leaf Fractions With Molecular Docking Study Of Potential Fraction, 2024 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta, Indonesia

#### 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 …

Thermal Phase Fluctuations In Narrow Superfluid Rings, 2024 Dartmouth College

#### Thermal Phase Fluctuations In Narrow Superfluid Rings, Parth Sabharwal

*Dartmouth College Ph.D Dissertations*

Remarkable advances have been made in the past decade in the ability to control superfluids in circuit-like configurations. Especially notable are the improvements in the initialization, stabilization and measurement of the circulation of superfluids in geometries with periodic boundary conditions, such as rings. This has significant implications for applications as rotation sensors, magnetometers, and in the emerging field of atomtronics. As the push towards studying supercurrents in lower dimensions and higher aspect ratios continues, in order to realize idealized experimental conditions and explore unusual quantum phases, phase fluctuations become increasingly pronounced, with the potential to destroy long-range order. In this …

Optically Targeted Search For Gravitational Waves Emitted By Core-Collapse Supernovae During The Third Observing Run Of Advanced Ligo And Advanced Virgo, 2024 The University of Texas Rio Grande Valley

#### Optically Targeted Search For Gravitational Waves Emitted By Core-Collapse Supernovae During The Third Observing Run Of Advanced Ligo And Advanced Virgo, Marek J. Szczepańczyk, Yanyan Zheng, Javier M. Antelis, Michael G. Benjamin, Marie-Anne Bizouard, Alejandro Casallas-Lagos, Pablo Cerda-Duran, Derek Davis, Dorota Gondek-Rosinska, Soma Mukherjee

*Physics and Astronomy Faculty Publications and Presentations*

We present the results from a search for gravitational-wave transients associated with core-collapse supernovae observed optically within 30 Mpc during the third observing run of Advanced LIGO and Advanced Virgo. No gravitational wave associated with a core-collapse supernova has been identified. We then report the detection efficiency for a variety of possible gravitational-wave emissions. For neutrino-driven explosions, the distance at which we reach 50% detection efficiency is up to 8.9 kpc, while more energetic magnetorotationally driven explosions are detectable at larger distances. The distance reaches for selected models of the black hole formation, and quantum chromodynamics phase transition are also …

Cosmic Variance Of The Hellings And Downs Correlation For Ensembles Of Universes Having Nonzero Angular Power Spectra, 2024 The University of Texas Rio Grande Valley

#### Cosmic Variance Of The Hellings And Downs Correlation For Ensembles Of Universes Having Nonzero Angular Power Spectra, Deepali Agarwal, Joseph D. Romano

*Physics and Astronomy Faculty Publications and Presentations*

Gravitational waves (GWs) induce correlated perturbations to the arrival times of pulses from an array of galactic millisecond pulsars. The expected correlations, obtained by averaging over many pairs of pulsars having the same angular separation (*pulsar averaging*) and over an ensemble of model universes (*ensemble averaging*), are described by the Hellings and Downs curve. As shown by Allen [Phys. Rev. D 107, 043018 (2023)], the pulsar-averaged correlation will not agree exactly with the expected Hellings and Downs prediction if the gravitational-wave sources interfere with one another, differing instead by a “cosmic variance” contribution. The …