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Articles 1291 - 1320 of 33925

Full-Text Articles in Physics

Swift-Bat Guano Follow-Up Of Gravitational-Wave Triggers In The Third Ligo–Virgo–Kagra Observing Run, Gayathri Raman, Samuele Ronchini, James Delaunay, Aaron Tohuvavohu, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang Feb 2025

Swift-Bat Guano Follow-Up Of Gravitational-Wave Triggers In The Third Ligo–Virgo–Kagra Observing Run, Gayathri Raman, Samuele Ronchini, James Delaunay, Aaron Tohuvavohu, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

We present results from a search for X-ray/gamma-ray counterparts of gravitational-wave (GW) candidates from the third observing run (O3) of the LIGO–Virgo–KAGRA network using the Swift Burst Alert Telescope (Swift-BAT). The search includes 636 GW candidates received with low latency, 86 of which have been confirmed by the offline analysis and included in the third cumulative Gravitational-Wave Transient Catalogs (GWTC-3). Targeted searches were carried out on the entire GW sample using the maximum-likelihood Non-imaging Transient Reconstruction and Temporal Search pipeline on the BAT data made available via the GUANO infrastructure. We do not detect any significant electromagnetic emission that is …


The Metaphysics Of Time Within Physics, Mohamed Ahmed Feb 2025

The Metaphysics Of Time Within Physics, Mohamed Ahmed

Theses and Dissertations

The starting point of this thesis is to shed some light on the metaphysical nature of time by reflecting on the physics of time. The aim of this approach is not to [dis]prove or defend a metaphysical position but rather to elucidate the metaphysical position that underlies [or is compatible with] our best scientific theories. This task will be demanding, not only because our best theories may carry different interpretations of their underlying temporal structure but also because there seems to be a conceptual conflict/incompatibility between the notion of time in relativity and quantum mechanics, which are the two major …


Fragmentation Functions For Light And Heavy Quarks In Simulated Proton-Proton Collisions, Nermin Kamal Sadoun Feb 2025

Fragmentation Functions For Light And Heavy Quarks In Simulated Proton-Proton Collisions, Nermin Kamal Sadoun

Theses and Dissertations

In the first microsecond after the Big Bang, the early universe is believed to have been in an excited state known as the Quark-Gluon Plasma (QGP) state, a state of free quarks and gluons. Conducted experiements, like Heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), have showed some evidences of the formation of this extreme states in the collisions. Jet quenching and elliptic flow are two phenomena that provide significant evidence for the creation of QGP and its distinctive characteristics. Although the major framework for studying QGP is still heavy-ion collisions, new research …


Absence Of Tev Halos Around Millisecond Pulsars, A. U. Abeysekara, R. Alfaro, C. Alvarez, 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, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, D. Depaoli, P. Desiati, N. Di Lalla, R. Diaz Hernandez, M. A. Duvernois, J. C. Diaz-Velez, K. Engel, T. Ergin, K. L. Fan, K. Fang, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez-Cadena, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, S. Kaufmann, D. Kieda, A. Lara, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Morales-Soto, E. Moreno, M. Mostafa, M. Najafi, L. Nellen, M. Newbold, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, M. A. Roth, H. Salazar, A. Sandoval, J. Serna-Franco, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, L. Villasenor, Xiaojie Wang, Z. Wang, I. J. Watson, H. Wu, S. Yu Feb 2025

Absence Of Tev Halos Around Millisecond Pulsars, A. U. Abeysekara, R. Alfaro, C. Alvarez, 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, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, D. Depaoli, P. Desiati, N. Di Lalla, R. Diaz Hernandez, M. A. Duvernois, J. C. Diaz-Velez, K. Engel, T. Ergin, K. L. Fan, K. Fang, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez-Cadena, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, S. Kaufmann, D. Kieda, A. Lara, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Morales-Soto, E. Moreno, M. Mostafa, M. Najafi, L. Nellen, M. Newbold, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, M. A. Roth, H. Salazar, A. Sandoval, J. Serna-Franco, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, L. Villasenor, Xiaojie Wang, Z. Wang, I. J. Watson, H. Wu, S. Yu

Physics Faculty Research & Creative Works

TeV halos are extended very-high-energy (VHE; 0.1-100 TeV) gamma-ray emission around middle-aged pulsars. So far, they have only been found around isolated pulsars, but it has been suggested that they may also be powered by millisecond pulsars (MSPs). We searched for VHE gamma-ray emission from MSPs reported by radio and GeV gamma-ray observatories in 2565 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. We found no significant emission from individual pulsars. By combining the likelihood profiles of all MSPs accessible to HAWC, our analysis suggests that the excess emission around the MSP population is consistent with a background. …


Super-Resolution Imaging Reveals Resistance To Mass Transfer In Functionalized Stationary Phases, Ricardo Monge Neria, Muhammad Zeeshan, Aman Kapoor, Tae Kyong John Kim, Nichole Hoven, Jeffrey S. Pigott, Burcu Gurkan, Christine E. Duval, Lydia Kisley Feb 2025

Super-Resolution Imaging Reveals Resistance To Mass Transfer In Functionalized Stationary Phases, Ricardo Monge Neria, Muhammad Zeeshan, Aman Kapoor, Tae Kyong John Kim, Nichole Hoven, Jeffrey S. Pigott, Burcu Gurkan, Christine E. Duval, Lydia Kisley

Faculty Scholarship

Chemical separations are costly in terms of energy, time, and money. Separation methods are optimized with inefficient trial-and-error approaches that lack insight into the molecular dynamics that lead to the success or failure of a separation and, hence, ways to improve the process. We perform super-resolution imaging of fluorescent analytes in five different commercial liquid chromatography materials. Unexpectedly, we observe that chemical functionalization can block more than 50% of the material’s porous interior, rendering it inaccessible to small-molecule analytes. Only in situ imaging unveils the inaccessibility when compared to the industry-accepted ex situ characterization methods. Selectively removing some of the …


Evaluating The New Nd: Yag Laser Method In Phytosynthesizing Silver Nanoparticles And Assessing Their Medical Applications., Arshad Mahdi Hamad, Qanat Mahmood Atiya Feb 2025

Evaluating The New Nd: Yag Laser Method In Phytosynthesizing Silver Nanoparticles And Assessing Their Medical Applications., Arshad Mahdi Hamad, Qanat Mahmood Atiya

Karbala International Journal of Modern Science

Silver nanoparticles (AgNPs) were synthesized via an innovative green synthesis method using amygdalin (Am) as a reducing agent and the Nd: YAG laser as a catalyst. We studied the properties of the nanoparticles using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV), and Fourier transform infrared spectroscopy (FTIR) techniques. All the results of the examination demonstrate excellent structural and optical properties. In addition, the molecular docking of the complex composed of amygdalin and AgNPs was tested on three proteins concerned with the virulence of Pseudomonas aeruginosa and …


Influence Of Oil Density On Self-Propelled Motion Of Belousov-Zhabotinsky Reaction Droplet, Vivek Bharat Meshram, Anupama Sebastian, Puthiyapurayil Sibeesh, T K Shajahan Feb 2025

Influence Of Oil Density On Self-Propelled Motion Of Belousov-Zhabotinsky Reaction Droplet, Vivek Bharat Meshram, Anupama Sebastian, Puthiyapurayil Sibeesh, T K Shajahan

Northeast Journal of Complex Systems (NEJCS)

Belousov-Zhabotinsky reaction serves as an example of the nonlinear chemical oscillator in which the reacting substance undergoes sequential oxidation and reduction. A droplet containing the BZ reaction, when placed within the oily environment, can self-propel. In this experimental work, we explore the effect of oil medium density on the BZ reaction droplet dynamics. In an oil medium with lower density, the BZ droplet exhibits higher speed and effective diffusivity but a shorter lifetime. Both the distance and speed of the droplet initially increase with droplet volume. However, beyond a critical volume, the distance decreases while the speed stays constant. Interestingly, …


Hierarchical Search Method For Gravitational Waves From Stellar-Mass Binary Black Holes In Noisy Space-Based Detector Data, Yao Fu, Yan Wang, Soumya D. Mohanty Feb 2025

Hierarchical Search Method For Gravitational Waves From Stellar-Mass Binary Black Holes In Noisy Space-Based Detector Data, Yao Fu, Yan Wang, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

Future space-based laser interferometric detectors, such as the Laser Interferometer Space Antenna (LISA), will be able to detect gravitational waves (GWs) generated during the inspiral phase of stellar-mass binary black holes (SmBBHs). These detections contain a wealth of important information concerning astrophysical formation channels and fundamental physics constraints. However, the detection and characterization of GWs from SmBBHs poses a formidable data analysis challenge, arising from the large number of wave cycles that make the search extremely sensitive to mismatches in signal and template parameters in a likelihood-based approach. This makes the search for the maximum of the likelihood function over …


Characterization Of 1,8-Cineole (Eucalyptol) From Myrtle And Its Potential Antibacterial And Antioxidant Activities*, Humera Khan Feb 2025

Characterization Of 1,8-Cineole (Eucalyptol) From Myrtle And Its Potential Antibacterial And Antioxidant Activities*, Humera Khan

Karbala International Journal of Modern Science

1,8-Cineole is a naturally occurring chemical molecule predominantly found in fragrant plants, particularly Myrtle. Its aroma is distinctive and has been the subject of numerous investigations due to its various biological actions. This study examines the characterization of 1,8-Cineole derived from Myrtle and investigates its antibacterial and antioxidant properties. This study seeks to compare 1,8-Cineole with antibiotics like Amoxicillin and Tetracycline, and moreover, to investigate its antioxidant capabilities against diverse bacterial strains (both Gram-positive and Gram-negative). 1,8-Cineole exhibits the most effective antibacterial properties, demonstrating an inhibition zone of 12.00 mm against Staphylococcus aureus and 10.00 mm against Pseudomonas aeruginosa. …


Convergent Close-Coupling Approach To Electron Scattering On H3+ : Scattering Dynamics And Dissociative Processes, Reese K. Horton, Michael V. Pak, Igor Bray, Dmitry V. Fursa Feb 2025

Convergent Close-Coupling Approach To Electron Scattering On H3+ : Scattering Dynamics And Dissociative Processes, Reese K. Horton, Michael V. Pak, Igor Bray, Dmitry V. Fursa

Faculty Publications

Cross sections for electron impact dissociative excitation and ionization in scattering on vibrationally excited levels of the ground electronic state of H3+, D3+, and T3+ are reported in the energy range of 8–1000 eV. Calculations have been performed using a newly developed version of the molecular convergent close-coupling code. Convergence of the cross sections with the size of the projectile partial-wave and close-coupling expansions is examined. Branching ratios and cross sections for the yields of D2+ and D+ from dissociative excitation of D3+ are presented and isotope …


Study Of Long-Term Spectral Evolution And X-Ray And Γ-Ray Correlation Of Blazars Seen By Hawc, 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, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Diaz-Velez, K. Engel, C. Espinoza, K. L. Fan, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, A. Gonzalez Munoz, M. M. Gonzalez, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernandez-Cadena, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, V. Joshi, S. Kaufman, D. Kieda, A. Lara, W. H. Lee, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, I. Martinez-Castellanos, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Montes, E. Moreno, M. Mostafa, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, M. Osorio, 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, M. 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, L. Villasenor, Xiaojie Wang, I. J. Watson, K. Whitaker, E. Willox, S. Yun-Carcamo, H. Zhou Feb 2025

Study Of Long-Term Spectral Evolution And X-Ray And Γ-Ray Correlation Of Blazars Seen By Hawc, 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, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Diaz-Velez, K. Engel, C. Espinoza, K. L. Fan, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, A. Gonzalez Munoz, M. M. Gonzalez, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernandez-Cadena, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, V. Joshi, S. Kaufman, D. Kieda, A. Lara, W. H. Lee, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, I. Martinez-Castellanos, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Montes, E. Moreno, M. Mostafa, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, M. Osorio, 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, M. 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, L. Villasenor, Xiaojie Wang, I. J. Watson, K. Whitaker, E. Willox, S. Yun-Carcamo, H. Zhou

Physics Faculty Research & Creative Works

The HAWC Observatory collected 6 yr of extensive data, providing an ideal platform for long-term monitoring of blazars in the very high energy (VHE) band, without bias toward specific flux states. HAWC continuously monitors blazar activity at TeV energies, focusing on sources with a redshift of z ≤ 0.3, based on the Third Fermi-LAT Catalog of High-Energy sources. We specifically focused our analysis on Mrk 421 and Mrk 501, as they are the brightest blazars observed by the HAWC Observatory. With a data set of 2143 days, this work significantly extends the monitoring previously published, which was based on 511 …


Convergent Close-Coupling Approach To Electron Impact Dissociation Of The Polyatomic Molecule H 3 + And Its Isotopologues, Reese K. Horton, Michael V. Pak, Igor Bray, Dmitry V. Fursa Feb 2025

Convergent Close-Coupling Approach To Electron Impact Dissociation Of The Polyatomic Molecule H 3 + And Its Isotopologues, Reese K. Horton, Michael V. Pak, Igor Bray, Dmitry V. Fursa

Faculty Publications

Cross sections for electron impact dissociative excitation and ionization in scattering on vibrationally excited levels of the ground electronic state of H3+ and its isotopologues are reported in the energy range of 8 to 1000 eV. Calculations have been performed using a newly developed version of the molecular convergent close-coupling code. Cross sections for total dissociative excitation, ionization yielding atomic fragments such as D+, and the total inelastic cross section are presented. Good agreement with available experiments has been demonstrated.


The Lyman Continuum Escape Fraction Of Star-Forming Galaxies At 2.4 ≲ Z ≲ 3.0 From Uvcandels, Xin Wang, Harry I. Teplitz, Brent M. Smith, Rogier A. Windhorst, Marc Rafelski, Vihang Mehta, Anahita Alavi, Zhiyuan Ji, Gabriel Brammer, James Colbert, Norman Grogin, Nimish P. Hathi, Anton M. Koekemoer, Laura Prichard, Claudia Scarlata, Ben Sunnquist, Pablo Arrabal Haro, Christopher Conselice, Eric Gawiser, Yicheng Guo, Matthew Hayes Feb 2025

The Lyman Continuum Escape Fraction Of Star-Forming Galaxies At 2.4 ≲ Z ≲ 3.0 From Uvcandels, Xin Wang, Harry I. Teplitz, Brent M. Smith, Rogier A. Windhorst, Marc Rafelski, Vihang Mehta, Anahita Alavi, Zhiyuan Ji, Gabriel Brammer, James Colbert, Norman Grogin, Nimish P. Hathi, Anton M. Koekemoer, Laura Prichard, Claudia Scarlata, Ben Sunnquist, Pablo Arrabal Haro, Christopher Conselice, Eric Gawiser, Yicheng Guo, Matthew Hayes

Pacific Faculty Work

The UltraViolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) survey is a Hubble Space Telescope (HST) Cycle-26 Treasury Program, allocated in total 164 orbits of primary Wide-Field Camera 3 Ultraviolet and VISible light F275W imaging with coordinated parallel Advanced Camera for Surveys F435W imaging, on four of the five premier extragalactic survey fields: GOODS-N, GOODS-S, EGS, and COSMOS. We introduce this survey by presenting a comprehensive analysis of the absolute escape fraction ( f esc abs ) of Lyman continuum radiation through stacking the UV images of a population of star-forming galaxies with secure redshifts …


Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull Feb 2025

Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Infrared (IR) cooling of polycyclic aromatic hydrocarbon (PAH) molecules is a major radiative stabilization mechanism of PAHs present in space and is the origin of the aromatic infrared bands (AIBs). Here, we report an anharmonic cascade model in a master equation framework to model IR emission rates and emission spectra of energized PAHs as a function of internal energy. The underlying (simple harmonic cascade) framework for fundamental vibrations has been developed through the modeling of cooling rates of PAH cations and other carboneaous ions measured in electrostatic ion storage ring experiments performed under “molecular cloud in a box” conditions. The …


Magnetus: A Magnetized Plasma Research Ecosystem, N. C. Hurst, M. Abler, Michael R. Brown, J. Juno, E. G. Kostadinova, N. A. Murphy, J. Olson, D. M. Orlov, D. B. Schaeffer, D. A. Schaffner, E. E. Scime, T. M. Tenbarge, S. C. Thakur Feb 2025

Magnetus: A Magnetized Plasma Research Ecosystem, N. C. Hurst, M. Abler, Michael R. Brown, J. Juno, E. G. Kostadinova, N. A. Murphy, J. Olson, D. M. Orlov, D. B. Schaeffer, D. A. Schaffner, E. E. Scime, T. M. Tenbarge, S. C. Thakur

Physics & Astronomy Faculty Works

MagNetUS is a network of scientists and research groups that coordinates and advocates for fundamental magnetized plasma research in the USA. Its primary goal is to bring together a broad community of researchers and the experimental and numerical tools they use in order to facilitate the sharing of ideas, resources and common tasks. Discussed here are the motivation and goals for this network and details of its formation, history and structure. An overview of associated experimental facilities and numerical projects is provided, along with examples of scientific topics investigated therein. Finally, a vision for the future of the organization is …


Helicity Modulus And Chiral Symmetry Breaking For Boundary Conditions With Finite Twist, Gaurav Khairnar, Thomas Vojta Feb 2025

Helicity Modulus And Chiral Symmetry Breaking For Boundary Conditions With Finite Twist, Gaurav Khairnar, Thomas Vojta

Physics Faculty Research & Creative Works

We study the response of a two-dimensional classical XY model to a finite (noninfinitesimal) twist of the boundary conditions. We use Monte Carlo simulations to evaluate the free energy difference between periodic and twisted-periodic boundary conditions and find deviations from the expected quadratic dependence on the twist angle. Consequently, the helicity modulus (spin stiffness) shows a nontrivial dependence on the twist angle. We show that the deviation from the expected behavior arises because of the mixing of states with opposite chirality which leads to an additional entropy contribution in the quasi-long-range ordered phase. We give an improved prescription for the …


Controlling Structural Phases Of Sn Through Lattice Engineering, Chandima Kasun Edirisinghe, Anjali Rathore, Taegeon Lee, Daekwon Lee, An Hsi Chen, Garrett Baucom, Eitan Hershkovitz, Anuradha Wijesinghe, Pradip Adhikari, Sinchul Yeom, Hong Seok Lee, Hyung Kook Choi, Hyunsoo Kim, Mina Yoon Feb 2025

Controlling Structural Phases Of Sn Through Lattice Engineering, Chandima Kasun Edirisinghe, Anjali Rathore, Taegeon Lee, Daekwon Lee, An Hsi Chen, Garrett Baucom, Eitan Hershkovitz, Anuradha Wijesinghe, Pradip Adhikari, Sinchul Yeom, Hong Seok Lee, Hyung Kook Choi, Hyunsoo Kim, Mina Yoon

Physics Faculty Research & Creative Works

Topology and superconductivity, two distinct phenomena, offer unique insight into quantum properties and their applications in quantum technologies, spintronics, and sustainable energy technologies. Tin (Sn) plays a pivotal role here as an element because of its two structural phases, α-Sn exhibiting topological characteristics and β-Sn showing superconductivity. Here, we demonstrate precise control of these phases in Sn thin films using molecular beam epitaxy with systematically varied lattice parameters of the buffer layer. The Sn films exhibit either β-Sn or α-Sn phases as the buffer layer's lattice constant varies from 6.10Å to 6.48Å, spanning the range from GaSb (like InAs) to …


Novel Alchemical Methodologies For Modeling Molecular Binding, Solmaz Azimi Feb 2025

Novel Alchemical Methodologies For Modeling Molecular Binding, Solmaz Azimi

Dissertations, Theses, and Capstone Projects

Molecular recognition is fundamental to all biological and biochemical processes. Understanding the interactions between molecules is the foundation for drug discovery and development, for understanding biological processes, and for the design of biosensors and nanomaterials. There is tremendous interest in the development of computer models to predict molecular association equilibria. In structure-based drug discovery enterprises, predicting the strength and selectivity of a small molecule to a biological target can advance target identification, aid ligand design, and accelerate high-throughput screening of drug compounds. This work focuses on free energy models, a class of computational methodologies grounded on the fundamental physical and …


Leveraging Collective Impact To Characterize And Identify Solutions To Cultural Challenges Within Scientific Societies, Taylor Lightner, Simone B. Soso, Candice M. Etson, Robin Mc C. Greenler, Mercy Mugo, Verónica A. Segarra Feb 2025

Leveraging Collective Impact To Characterize And Identify Solutions To Cultural Challenges Within Scientific Societies, Taylor Lightner, Simone B. Soso, Candice M. Etson, Robin Mc C. Greenler, Mercy Mugo, Verónica A. Segarra

Physics: Faculty Publications

A consortium of scientific societies recently identified challenges to inclusivity within the biology communities they represent. Specifically, societies encounter difficulties collecting member demographic data effectively, integrating scientists at transitional career stages, and diversifying their leadership. In response, the Leveraging, Enhancing, and Developing Biology (LED-BIO) research coordination network (NSF 2134725) organized two meetings at the Marine Biological Laboratory in Woods Hole, MA to gather stakeholders and employ top-down and bottom-up organizational approaches to address these challenges. These meetings included Town Hall and Think Tank events to facilitate open dialogue and gather feedback on policies and programs from national organizations in attendance. …


The Role Of Secondary And Tertiary Structure In The Cap-Independent Translation Of Fgf-9 And Hif-1-Alpha, Amanda Michelle Whittaker Feb 2025

The Role Of Secondary And Tertiary Structure In The Cap-Independent Translation Of Fgf-9 And Hif-1-Alpha, Amanda Michelle Whittaker

Dissertations, Theses, and Capstone Projects

Under normoxic conditions, eukaryotes initiate translation of RNA through eIF4E recognition of the 5’ cap. However, under cellular stress, eukaryotic translation must be initiated through a 4E-independent, or “cap-independent” mechanism, involving eukaryotic initiation factor 4G (eIF4G) binding directly to the 5’ untranslated regions (5’ UTR) of the RNA. eIF4G binding then recruits the ribosome to the transcript. While this mechanism is useful for translation of apoptotic transcripts and transcripts involved in cell survival, cap-independent translation is also utilized by oncogenic RNA for tumorigenesis. Previous work by our lab and others has categorized this recruitment and initiation mechanism as either internal-ribosome-entry-site …


Underlying Mechanisms Of Quantum Emission In Hexagonal Boron Nitride, Enrique Alejandro Mejia Iv Feb 2025

Underlying Mechanisms Of Quantum Emission In Hexagonal Boron Nitride, Enrique Alejandro Mejia Iv

Dissertations, Theses, and Capstone Projects

Quantum emitters in hexagonal boron nitride (hBN) have emerged as promising candidates for advancing numerous quantum technologies. Visible-spectrum quantum emitters, in particular, have gained significant attention due to their exceptional properties, including high brightness, observable spin structure, and highly tunable emission wavelengths. However, several challenges hold back the practical implementation of hBN-based quantum emitters in technological applications—namely, the unknown physical structure of the emitters, susceptibility to spectral wandering and blinking, and limited understanding of how to control their broad spectral distribution.

In this dissertation, we investigate the collective properties of highly defective hBN. To address the key challenges, we develop …


Silver-Alloyed Cigs Thin-Film Solar Cells On Flexible Stainless-Steel Substrate, Zhi Huang Feb 2025

Silver-Alloyed Cigs Thin-Film Solar Cells On Flexible Stainless-Steel Substrate, Zhi Huang

Dissertations, Theses, and Capstone Projects

Our dissertation demonstrates the optimization of ACIGS (Ag-Cu-In-Ga-Se) thin-film solar cells, achieving an efficiency of 20.4% through the combined effects of silver incorporation and alkali metal post-deposition treatment (PDT). The incorporation of 2.8% Ag into the CIGS lattice enhanced crystal quality, reduced disorder, and widened the bandgap by 0.103 eV, as evidenced by a significant reduction in Urbach energy. These improvements resulted in stronger light absorption, increased carrier generation, and enhanced photovoltaic parameters, including a short-circuit current density Jsc of 35.31 mA/cm², an open-circuit voltage Voc of 0.74 V, and a fill factor (FF) of 75.8%. PDT using rubidium fluoride …


Taming Biological Complexity Through The Use Of Symmetries, Luis A. Álvarez-García Feb 2025

Taming Biological Complexity Through The Use Of Symmetries, Luis A. Álvarez-García

Dissertations, Theses, and Capstone Projects

The study of biological systems is, inherently, the study of very complex systems. This is essentially due to the fact that they are made up of numerous, often very complicated, interactions between an extensive number of components. Often necessitating an abundance of quantitative parameters and details for a precise description. The human brain for ex- ample, consisting of ∼ 80 billion neurons with ∼ 800 to 100 trillion connections between them, each of them depending on a large set of parameters. Even simpler examples such as bacterial organisms, such as E. coli and B. subtilis, which we focus on …


Offshore Wind Farms Could Impact Coastal Marine Heatwaves In Eastern Boundary Upwelling Systems, Michael Dalsin, Ryan K. Walter, Piero L.F. Mazzini Feb 2025

Offshore Wind Farms Could Impact Coastal Marine Heatwaves In Eastern Boundary Upwelling Systems, Michael Dalsin, Ryan K. Walter, Piero L.F. Mazzini

Physics

Analysis of ecosystem impacts from offshore wind (OSW) farm development has primarily focused on localized effects. However, in Eastern Boundary Current Upwelling Systems (EBUS) like the California Current, OSW farms can modify the intensity and spatial structure of wind-driven upwelling, inducing non-local (tens of kms away) changes to seawater temperature. Recent numerical modeling research determined that a hypothetical upper bound full buildout of OSW farms in central California could warm coastal waters through a reduction in upwelling. Here, we examine the sensitivity of coastal marine heatwaves (MHWs), which are prolonged extreme seawater temperatures that are among the greatest threats to …


Anderson Transition For Light In A Three-Dimensional Random Medium, Alexey Yamilov, Hui Cao, Sergey E. Skipetrov Jan 2025

Anderson Transition For Light In A Three-Dimensional Random Medium, Alexey Yamilov, Hui Cao, Sergey E. Skipetrov

Physics Faculty Research & Creative Works

We study Anderson transition for light in three dimensions by performing large-scale simulations of electromagnetic wave transport in disordered ensembles of perfect-electric-conducting spatially overlapping spheres. A mobility edge that separates diffusive transport and Anderson localization is identified, revealing a sharp transition from diffusion to localization for light. Critical behavior in the vicinity of the mobility edge is well described by a single parameter scaling law. The critical exponent is found to be consistent with the value known for the Anderson transition of the orthogonal universality class. Statistical distribution of total transmission at the mobility edge is described without any fit …


An Effective Secure Multi-Objective Task Scheduling Algorithm In Multi-Cloud Environment, V K S K Sai Vadapalli, Ramesh Babu Gurujukota, Phaneendra Varma Chintalapati, Satyanarayana Murty, G. Sai Chaitanya Kumar, Satish Kumar Kode Jan 2025

An Effective Secure Multi-Objective Task Scheduling Algorithm In Multi-Cloud Environment, V K S K Sai Vadapalli, Ramesh Babu Gurujukota, Phaneendra Varma Chintalapati, Satyanarayana Murty, G. Sai Chaitanya Kumar, Satish Kumar Kode

Karbala International Journal of Modern Science

In cloud environments, task scheduling is essential for improving performance. Nevertheless, the existence of several heterogeneous clouds makes scheduling extremely difficult, requiring increasingly advanced algorithms to manage these environments' diversity and dynamic nature. To solve this, numerous authors have created a variety of task schedulers utilizing heuristic and metaheuristic techniques. Nevertheless, it remains dynamic and challenging because task scheduling is an NP-hard issue. Furthermore, in many complicated situations, it is still problematic to guarantee security throughout the task’s execution. Therefore, this paper introduces a multi-objective security-aware task scheduler using the Crayfish Mud Ring Optimization Algorithm for a multi-cloud environment. This …


Carbon And Iron Deficiencies In Quiescent Galaxies At Z = 1-3 From Jwst-Suspense: Implications For The Formation Histories Of Massive Galaxies, Aliza G. Beverage, Martje Slob, Mariska Kriek, Charlie Conroy, Guillermo Barro, Rachel Bezanson, Gabriel Brammer, Chloe M. Cheng, Anna De Graaff, Natascha M. Förster Schreiber, Marijn Franx, Brian Lorenz, Pavel E. Mancera Piña, Danilo Marchesini, Adam Muzzin, Andrew B. Newman, Sedona H. Price, Alice E. Shapley, Mauro Stefanon, Katherine A. Suess, Pieter Van Dokkum Jan 2025

Carbon And Iron Deficiencies In Quiescent Galaxies At Z = 1-3 From Jwst-Suspense: Implications For The Formation Histories Of Massive Galaxies, Aliza G. Beverage, Martje Slob, Mariska Kriek, Charlie Conroy, Guillermo Barro, Rachel Bezanson, Gabriel Brammer, Chloe M. Cheng, Anna De Graaff, Natascha M. Förster Schreiber, Marijn Franx, Brian Lorenz, Pavel E. Mancera Piña, Danilo Marchesini, Adam Muzzin, Andrew B. Newman, Sedona H. Price, Alice E. Shapley, Mauro Stefanon, Katherine A. Suess, Pieter Van Dokkum

Pacific Faculty Work

We present the stellar metallicities and multielement abundances (C, Mg, Si, Ca, Ti, Cr, and Fe) of 15 massive (log M/M⊙ = 10.2-11.2) quiescent galaxies at z = 1-3, derived from ultradeep JWST-SUSPENSE spectra. Compared to quiescent galaxies at z ∼ 0, these galaxies exhibit a deficiency of 0.26 ± 0.04 dex in [C/H], 0.16 ± 0.03 dex in [Fe/H], and 0.07 ± 0.04 dex in [Mg/H], implying rapid formation and quenching before significant enrichment from asymptotic giant branch stars and Type Ia supernovae. Additionally, we find that galaxies forming at higher redshift consistently show higher [Mg/Fe] and lower [Fe/H] …


3F4 Hypergeometric Functions As A Sum Of A Product Of 1F2 Functions, Jack C. Straton Jan 2025

3F4 Hypergeometric Functions As A Sum Of A Product Of 1F2 Functions, Jack C. Straton

Physics Faculty Publications and Presentations

This paper shows that certain 3F4 hypergeometric functions can be expanded in sums of pair products of 1F2 functions. In special cases, the 3F4 hypergeometric functions reduce to 2F3 functions. Further special cases allow one to reduce the 2F3 functions to 1F2 functions, and the sums to products of 0F1 (Bessel) and 1F2 functions. The class of hypergeometric functions with summation theorems are thereby expanded beyond those expressible as pair-products of 2F1 functions, 3F2 functions, and generalized Whittaker functions, into …


Breaking Barriers: Investigating Gender Dynamics In Introductory Physics Lab Classes, Bilas Paul, Shantanu Chakraborty, Ganga Sharma Jan 2025

Breaking Barriers: Investigating Gender Dynamics In Introductory Physics Lab Classes, Bilas Paul, Shantanu Chakraborty, Ganga Sharma

Georgia Journal of Science

The persistent underrepresentation of women and other gender minorities in physical science fields has been an ongoing concern. This study investigates gender dynamics in introductory physics laboratory courses, focusing on whether students of different gender identities exhibit equal inclination and confidence in conducting lab experiments, and whether they face barriers that impact their participation. Conducted across three institutions and involving non-physics STEM students enrolled in algebra-based and calculus-based physics courses, the study found mixed results, with two institutions showing no significant gender-based differences in participation levels during lab activities, while one institution demonstrated significant differences. Chi-square tests revealed no significant …


Single-Molecule Dna-Flow Stretching Assay As A Versatile Hybrid Tool For Investigating Dna-Protein Interactions, Sadaf Shehzad, Hyeongjun Kim Jan 2025

Single-Molecule Dna-Flow Stretching Assay As A Versatile Hybrid Tool For Investigating Dna-Protein Interactions, Sadaf Shehzad, Hyeongjun Kim

Physics & Astronomy Faculty Publications

Single-molecule techniques allow researchers to investigate individual molecules and obtain unprecedented details of the heterogeneous nature of biological entities. They play instrumental roles in studying DNA-protein interactions due to the ability to visualize DNA or proteins and to manipulate individual DNA molecules by applying force or torque. Here, we describe single-molecule DNA-flow stretching assays as hybrid tools that combine forces with fluorescence. We also review how widely these assays are utilized in elucidating working mechanisms of DNA-binding proteins. Additionally, we provide a brief explanation of various efforts to prepare DNA substrates with desired internal protein-binding sequences. More complicated needs for …