A Molecular Dynamics Study Of Single Crystal And Intergranular Crack Growth Behavior In WX M1−X Binary Aloys (M = V, Mo, Ta, Re),
2025
Air Force Institute of Technology
A Molecular Dynamics Study Of Single Crystal And Intergranular Crack Growth Behavior In WX M1−X Binary Aloys (M = V, Mo, Ta, Re), Samuel C. Wagers, Adib J. Samin
Faculty Publications
This study employs molecular dynamics simulations to investigate the fracture behavior of four binary refractory alloys WxM1−x (M = V, Mo, Ta, Re) and their dependence on crystallographic orientation, composition, and grain boundary (GB) structure, focusing on six distinct low-sigma grain boundaries. The simulations reveal that the effect of composition is complex with the most pronounced effect, accompanied by the maximum or minimum stress intensity factor, generally occurring at intermediate compositions. All compositions showed a higher fracture resistance in the [110] orientation compared to the [100] orientation. There was a strong thermodynamic tendency for Mo and V, …
Monitoring The Degradation Of Methylammonium Lead Iodide Perovskite Thin Films By Uv Exposure,
2025
Macalester College
Monitoring The Degradation Of Methylammonium Lead Iodide Perovskite Thin Films By Uv Exposure, Addison Dau, Ethan Dale, James Heyman
Macalester Journal of Physics and Astronomy
This project involved lead-halide perovskite thin films, a promising novel solar cell material. The goal was to monitor the composition of the samples during degradation from blue light exposure using vibrational spectroscopy. IR and THz spectroscopy measured the composition of the samples in-situ between periods of blue light exposure, probing the N-H and Pb-I vibrational modes. Plotting MA and MAPI concentrations versus blue light exposure showed that the MA and MAPI concentrations initially decreased in a gradual linear fashion until a threshold photon flux where both vibrational absorption bands simultaneously collapsed. This suggests that there is a discontinuous change in …
2d Cuo/Rgo Nanocomposite: A Novel Architecture For Enhanced Cr(Vi) Photo-Reduction,
2025
Port said University
2d Cuo/Rgo Nanocomposite: A Novel Architecture For Enhanced Cr(Vi) Photo-Reduction, Islam Gomaa, Nasser M. Hosny, Medhat A. Ibrahim
Nanotechnology Research Centre
he urgent need for efficient detoxification of carcinogenic hexavalent chromium (Cr(VI)) in aquatic environments has driven the development of advanced photocatalytic materials. This study presents the synthesis of 2D CuO/reduced graphene oxide (rGO) nanocomposite via probe sonication, designed to synergistically enhance the photocatalytic reduction of Cr(VI) to less toxic Cr(III). The nanocomposite was meticulously characterized using XRD, HRTEM, FESEM, XPS, and UV-Vis diffuse reflectance spectroscopy. Structural analysis confirmed the formation of CuO nanosheets (average size: 396 nm, thickness: 6 nm) integrated with rGO, where the rGO acted as an electron acceptor, mitigating charge recombination. XPS revealed Cu²⁺ in CuO and …
The Thermodynamic Fate Of Isolated Quantum Systems,
2025
Ursinus College
The Thermodynamic Fate Of Isolated Quantum Systems, John Keim, Isabel Martinez-Robles, Nicolaus A. Chlanda, Sage M. Thomas, Maja Teofilovska, Sarah E. Spielman, Jordyn Strunk, Tina Zhao, Juniper J. Bauroth-Sherman, Hannah Conley, Philip Conte, Aidan Kirk, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Summer Fellows
Isolated quantum systems are typically observed to come to thermal equilibrium. The weak Eigenstate Thermalization Hypothesis (wETH) states that the vast majority of eigenvectors are thermal. This implies that most initial states should thermalize. Studying the rare cases in which they fail to thermalize could reveal insight into quantum dynamics. In our experiment, we excite Rydberg atoms and allow them to exchange energy via dipole-dipole interactions. We find that they do not thermalize. We present numerical and theoretical results that show that our experimental initial state is not typical.
The Spectral Response Of Time-Resolved Piv In A Turbulent Boundary Layer,
2025
Defence Science and Technology Group
The Spectral Response Of Time-Resolved Piv In A Turbulent Boundary Layer, Peter Manovski, Wagih Abu Rowin, Henry Ng, Paul Gulotta, Matteo Giacobello, Charitha De Silva, Nicholas Hutchins, Ivan Marusic
Student Publications
This study presents the application of time-resolved particle image velocimetry (TR-PIV) to measure the mean and fluctuating velocity components in a turbulent boundary layer (TBL) over an axisymmetric body of revolution. A narrow wall-normal strip of the flow was captured using a synchronised high-speed laser and camera at a recording frequency of up to 80 kHz. The resulting streamwise and wall-normal velocity TR-PIV data were validated against hot-wire anemometry measurements and direct numerical simulations (DNS) of a flat plate under matched flow conditions. The mean flow results showed good agreement between all methods, while the expected attenuation due to the …
Shrinkage Study In Photopolymerisable Hybrid Sol-Gel Through Holographic Patterning,
2025
TU Dublin
Shrinkage Study In Photopolymerisable Hybrid Sol-Gel Through Holographic Patterning, Jamshed Aftab, Izabela Naydenova, Tatsiana Mikulchyk
Articles
Photopolymerisation induced shrinkage of holographic materials is one of the main factors which needs to be considered for designing holographic optical elements (HOEs) with high accuracy in light redirection with maximum efficiency. This work studies the shrinkage in photopolymerisable hybrid sol-gel (PHSG) by examining the properties of volume transmission gratings recorded in PHSG layers. It explores both the dependence of shrinkage on the holographic grating parameters (thickness, spatial frequency, slant angle) and the effect of material aging. By using the fringe-plane rotation model, shrinkage is found to have the maximum value of 1.37 % at 765 lines/mm (19.36° slant angle) …
Fused-Silica Microelectromechanical Systems For Relative Gravimetry,
2025
Air Force Institute of Technology
Fused-Silica Microelectromechanical Systems For Relative Gravimetry, Ethan Doerstling
Theses and Dissertations
Gravimeters are devices that measure gravitational acceleration which can be used by the United States Air Force (USAF) in the areas of navigation and remote sensing. Fused-silica microelectromechanical systems (MEMS) devices offer capabilities to make inexpensive relative gravimeters with higher thermal stability than common silicon devices while maintaining good gravitational sensitivity. The fused-silica devices in this research were designed, simulated, fabricated, and tested to observe their performance as gravimeters. The devices exhibit properties of highly sensitive accelerometers but the current designs do not qualify as gravimeters. This study provides information to improve the sensitivity and stability of these fused-silica MEMS …
Multi-Modal Mri For The Pre-Clinical Evaluation Of Hiv-Linked Changes In The Central Nervous System,
2025
University of Nebraska Medical Center
Multi-Modal Mri For The Pre-Clinical Evaluation Of Hiv-Linked Changes In The Central Nervous System, Gabriel Gauthier
Theses & Dissertations
Though the inception of anti-retroviral therapy (ART) has fundamentally changed the life expectancy of human immunodeficiency virus (HIV) patients, accessibility and outcomes vary enormously along demographic lines. Even for people living with HIV (PLWH) with perfect access and adherence to anti-retroviral drugs (ARVs), modern treatment plans are fundamentally unable to secure complete viral remission for patients. The cause of this perpetual infection is the persistence of viral reservoirs in the central nervous system (CNS), hidden beyond the reach of modern ARVs, leaving patients to deal with lifelong medication side-effects and risks of developing HIV-associated neurodegenerative disorders (HAND). Despite improving outcomes …
Nonthermalizing Dynamics Of Interacting Rydberg Atoms,
2025
Ursinus College
Nonthermalizing Dynamics Of Interacting Rydberg Atoms, Nicolaus A. Chlanda
Physics and Astronomy Honors Papers
An isolated system of ultracold Rydberg atoms can come to equilibrium by exchanging energy through dipole-dipole interactions. In our experiment, a static electric field of a few V/cm shifts the energy levels of the atoms, so that the energy levels are nearly degenerate at zero field and fan out with increasing field to form a manifold. We excite atoms to energy levels near the center of the manifold, where the spacing is nearly harmonic. We allow them to interact for a few microseconds, by which time the population of each energy level has reached a steady state. The population is …
Theoretical Proof Of And Proposed Experimental Search For The Ground Triplet State Of A Wigner-Regime Two-Electron ‘Artificial Atom’ In A Magnetic Field,
2025
Sacred Heart University
Theoretical Proof Of And Proposed Experimental Search For The Ground Triplet State Of A Wigner-Regime Two-Electron ‘Artificial Atom’ In A Magnetic Field, Marlina Slamet, Viraht Sahni
Publications and Research
It is experimentally established that there is no ground triplet state of the natural He atom. There is also no exact analytical solution to the Schrödinger equation corresponding to this state. For a two-dimensional two-electron ‘artificial atom’ or a semiconductor quantum dot in a magnetic field, as described by the Schrödinger–Pauli equation, we provide theoretical proof of the existence of a ground triplet state by deriving an exact analytical correlated wave function solution to the equation. The state exists in the Wigner high-electron-correlation regime. We further explain that the solution satisfies all requisite symmetry and electron coalescence constraints of …
Unpaired Virtual Histological Staining Of Tissue From Autofluorescence Using Regularized Cycle-Consistent Adversarial Networks,
2025
CUNY Hunter College
Unpaired Virtual Histological Staining Of Tissue From Autofluorescence Using Regularized Cycle-Consistent Adversarial Networks, Zhesi Wen
Theses and Dissertations
We present a regularized CycleGAN with a Dense Residual U-Net to virtually stain autofluorescence images of tissue into H&E-like images. Our method outperforms standard architectures, reduces artifacts, and achieves superior FID scores, enabling efficient, label-free, and accurate digital pathology for unpaired datasets using multi-channel fluorescence inputs.
The Search For Slow Particles And Magnetic Monopoles With Nova,
2025
University of South Alabama
The Search For Slow Particles And Magnetic Monopoles With Nova, John Clark
Poster Presentations
Singular magnetic poles, north or south, have been theorized to exist for hundreds of years. In the modern day, the elusive singular magnetic pole still remains undiscovered. The appearance of this particle would help confirm many Grand Unified Theories, GUTs, and revolutionize our understanding of some of the fundamental forces of the universe. Fermilab's NOvA collaboration is working on ways to screen and detect magnetic monopoles and other slow-moving particles coming from outer space alongside their main mission to study neutrinos. The aim of this work is to determine and improve the Far Detector’s efficiency at identifying slow moving particles. …
New Mathematical Approaches To Ultra-Cold Atoms,
2025
University of Massachusetts Boston
New Mathematical Approaches To Ultra-Cold Atoms, Joanna Ruhl
Graduate Doctoral Dissertations
This dissertation addresses three main themes: cold atoms, integrability, and number theory. In this dissertation we present novel approaches to four models, each of which touches on at least two of the three themes. At the intersection of cold atoms and integrability, we present a Lagrange bracket formalism that allows for exact computation of initial quantum fluctuations of soliton breathers which previously could only be estimated numerically, and the advance in software tools developed in Python to facilitate studies of two-dimensional disc breathers. At the intersection of integrability and number theory, we present a propagator for the Newman-Moore, or triangular …
Gravity Wave Breaking Over Northern Utah With An Advanced Mesospheric Temperature Mapper And Sodium Lidar,
2025
Utah State University
Gravity Wave Breaking Over Northern Utah With An Advanced Mesospheric Temperature Mapper And Sodium Lidar, Eric Davis
All Graduate Reports and Creative Projects, Fall 2023 to Present
Considerable progress has been made in recent decades in the understanding of gravity wave (GW) dynamics. However, there remain important aspects and effects that are poorly understood. In particular, the coupling and deposition of their energy and momentum into the mesosphere lower thermosphere (MLT) region and the interaction and instability dynamics that are directly associated with GW breaking. Using an Advanced Mesosphere Temperature Mapper (AMTM) several strong wave breaking events were observed in the summer of 2015 at USU’s BLO research station. These events have exhibited high momentum fluxes and associated strong wave breaking, prompting detailed data analyses. Rossby waves, …
The Search For Slow Particles And Magnetic Monopoles With Nova,
2025
University of South Alabama
The Search For Slow Particles And Magnetic Monopoles With Nova, John Clark
Honors Theses
Singular magnetic poles, north or south, have been theorized to exist for hundreds of years. In the modern day, the elusive singular magnetic pole still remains undiscovered. The appearance of this particle would help confirm many Grand Unified Theories, GUTs, and revolutionize our understanding of some of the fundamental forces of the universe. Fermilab's NOvA collaboration is working on ways to screen and detect magnetic monopoles and other slow-moving particles coming from outer space alongside their main mission to study neutrinos. The aim of this work is to determine and improve the Far Detector’s efficiency at identifying slow moving particles. …
Effects Of Group Delay Dispersion In Silica Glass On Non-Gaussian Laser Pulses,
2025
University of Nebraska-Lincoln
Effects Of Group Delay Dispersion In Silica Glass On Non-Gaussian Laser Pulses, Lars Pedersen
Honors Program: Senior Projects (Public)
We present an analysis of how the group delay dispersion in silica glass affects the envelope of non-Gaussian laser pulses. In particular, we examine femtosecond pulses in the ultraviolet regime with cosine squared and symmetric exponential envelope shapes. For both envelope shapes, our results show a linear or semi-linear dependence of both the maximum electric field strength and duration on the group delay dispersion when the pulse passes through the silica glass medium with a thickness between 1 μm and 10 μm. This computational analysis is done using a fast Fourier transform method.
Power-Beaming: Wireless Energy Transfer Using Lasers,
2025
Arkansas Tech University
Power-Beaming: Wireless Energy Transfer Using Lasers, Spencer L. Barnett
ATU Scholars Symposium
The objective of the project is to implement a wireless energy transfer system utilizing laser technology. This system involves modulating the laser’s beam profile and spatial distribution through precise optical manipulation. The energy transmitted by the laser is captured by a photovoltaic array, commonly referred to as a solar panel, which is engineered to convert incident photons into direct current (DC) electrical power. The current challenge is to develop a reliable wireless energy transfer mechanism capable of operating over extended distances, thereby overcoming the constraints imposed by wired connections, particularly in environments where wiring is impractical, such as in space. …
Computational Analysis Of Proton Conductivity Factors In Grotthuss-Style Mechanisms,
2025
Ursinus College
Computational Analysis Of Proton Conductivity Factors In Grotthuss-Style Mechanisms, Brock Dyer
Physics and Astronomy Honors Papers
The mechanism and fundamental molecular properties involved in proton conduction are discussed. Four calculable properties are presented: the proton affinity, binding energy (between protonated and neutral forms), intramolecular tautomerization barrier, and proton hopping barrier. An overview of the computational methods used in this thesis, including an introduction to the many-body Schrödinger equation and Density Functional Theory, as well as a look at Plane-Wave Density Functional Theory and Gaussian-Type Orbital Density Functional Theory are presented. 4,5-dimethyl-[1,2,3]-triazole is used as a model system, with 10 variations being generated with varying amounts and positions of fluorine substitution on the methyl groups. Preliminary calculations …
Doppler Free Laser Spectroscopy,
2025
Fort Hays State University
Doppler Free Laser Spectroscopy, Luis F. Ayala
SACAD: Scholarly Activities
Using Doppler Free laser spectroscopy we observed ground state and excited state Hyperfine structure of Rb atoms Isotopes 85 and 87.
Are The Vibrational Modes Of Molecules Quantized,
2025
Fort Hays State University
Are The Vibrational Modes Of Molecules Quantized, Aniol Majoral Obradors
SACAD: Scholarly Activities
In electron scattering from N2 molecules we observe quantized vibrational levels of N2-. These vibrational levels are well suited for energy calibration when electron transmission of unknown molecules is performed.
