Physics Commons^™

Structural And Physical Properties Of Solid State Materials: Cegage, Cssni3, And Yb2Si2-XGeXAl, Liam J. Scanlon

Theses and Dissertations--Physics and Astronomy

We present studies of three independent solid state materials: CeGaGe, CsSnI₃, and Yb₂Si_2-xGe_xAl.

CeGaGe is a magnetic candidate Weyl semimetal. Magnetic Weyl semimetals have possible technological applications due to their electronically conducting bulk states, magnetic states, and topologically protected surface states. We grew single crystals of CeGaGe using the zone-refinement method and flux-growth method. With single crystal X-ray and neutron diffraction, we found that zone-refined CeGaGe crystallizes with the I4₁md symmetry (space group 109). With single crystal X-ray diffraction, we found that flux-grown samples of CeGaGe have the …

Metasurfaces And Their Applications In Photonic Devices, Shuwei Guo

Dissertations and Theses

Metasurfaces are flat artificial optical elements composed of dielectric and/or metallic nanostructures. They can manipulate light in unprecedented ways by altering amplitude, phase, and polarization at subwavelength scales. The ability of these two-dimensional elements to perform multiple optical functions within compact optical systems—while offering high functionality, small form factors, and easy integration into optoelectronic devices—has sparked significant interest across various fields and industries. These applications span imaging, sensing, nonlinear and quantum optics, optical computing, automotive technology, augmented and virtual reality, and more.

In this dissertation, we explore and design new multifunctional metasurfaces with a focus on manipulating spectral responses. First, …

Photocarrier Dynamics In Dielectric And Metal-Dielectric Nanocatalysts In Ambient And Operando Conditions, Sunil Gyawali

Graduate Theses, Dissertations, and Problem Reports (ETD)

Photocatalysis, a promising method for solar-to-chemical energy conversion, relies on sunlight to generate excited charge carriers in catalysts with sufficient lifetimes and mobilities to drive photoreactions. Thin-film semiconductors are essential for reducing charge recombination and enhancing mobility but suffer from a low surface-to-volume ratio problems, resulting in a reduced absorption coefficient and limiting solar-energy-conversion efficiency. Nanostructures address these limitations by enhancing light absorption and surface reactivity. However, efficient photocatalysis also requires that the semiconductor’s band edges align with the redox potential of the desired photoreaction, limiting light absorption to just some of the whole solar spectrum. In hybrid and composite …

Eulerian Smoke Simulation With Multiple Fields, Diyang Zhang

Dartmouth College Master’s Theses

Fluid simulation is a cornerstone of computer graphics, enabling the realistic depiction of dynamic phenomena such as smoke, fire, and other gaseous behaviours. This thesis focuses on advancing Eulerian smoke simulation techniques, with a particular emphasis on grid-based simulations that capture intricate vortical structures and fine visual details.

We propose several detail-preserving frameworks that incorporate various scalar and vector fields within the simulation pipeline, including velocity, impulse, and Lamb vectors, along with their decompositions and transformed representations. By mathematically analyzing the properties of impulse, we derive its scalar fields decomposition (ImpSFD), which introduces an alternative numerical interpretation, and Vortex-Particles in …

Novel Methodology And Proof-Of-Concept For Proton Ct Using Spot Profile Rather Than Bragg Peak Location, Brett Albert Ruben

Open Access Dissertations

Proton radiation therapy offers a highly precise method for cancer treatment, theoretically providing superior dose deposition characteristics compared to conventional X-ray radiation therapy. Its steep and finite dose fall-off region allows for superior tumor coverage while reducing, though not eliminating, dose to surrounding healthy tissue. However, its full potential is limited by range uncertainties, particularly those arising from the reliance on X-ray-based imaging methods called computed tomography (CT) for proton-based treatment. CT image Hounsfield Units (HU) must be converted to stopping power ratios (SPR) as these ratios are the clinically relevant value for accurately planning particle interactions during proton therapy. …

A Universal Implementation Of Radiative Effects In Neutrino Event Generators, Júlia Tena-Vidal, Adi Ashkkenazi, Lawrence B. Weinstein, Peter Blunden, Steven Dytman, Noah Steinberg

Physics Faculty Publications

Due to the similarities between electron-nucleus (eA) and neutrino-nucleus scattering (νA), eA data can contribute key information to improve cross-section modeling in eA and hence in νA event generators. However, to compare data and generated events, either the data must be radiatively corrected or radiative effects need to be included in the event generators. We implemented a universal radiative corrections program that can be used with all reaction mechanisms and any eA event generator. Our program includes real photon radiation by the incident and scattered electrons, and virtual photon exchange and photon vacuum polarization diagrams. It …

Qcd Factorization With Multihadron Fragmentation Functions, T. C. Rogers, M. Radici, A. Courtoy, T. Rainaldi

Physics Faculty Publications

Important aspects of quantum chromodynamics (QCD) factorization theorems are the properties of the objects involved that can be identified as universal. One example is that the definitions of parton densitiesand fragmentation functions for different types of hadrons differ only in the identity of the nonperturbative states that form the matrix elements, but are otherwise the same. This leads to independence of perturbativecalculations on nonperturbative details of external states. It also lends support to interpretations ofcorrelation functions as encapsulations of intrinsic nonperturbative properties. These characteristics have usually been presumed to still hold true in fragmentation functions even when the observed nonperturbative …

Measurement Of Spin-Density Matrix Elements In Δ⁺⁺ (1232) Photoproduction, F. Ayzal, C. S. Akondi, M. Albrecht, M. Amaryan, S. Arrigo, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barringa, R. Barsotti, D. Barton, V. Baturin, V. V. Berdnikov, T. Black, W. Boeglin, M. Boer, W. J. Briscoe, T. Britton, S. Cao, E. Chudakov, G. Chung, P. L. Cole, O. Cortes, V. Crede, M. M. Dalton, D. Darulis, A. Deur, S. Dobbs, A. Dolgolenko, M. Dugger, R. Dzhygadlo, D. Ebersole, M. Edo, H. Egiyan, T. Erbora, P. Eugenio, A. Fabrizi, C. Fanelli, S. Fang, J. Fitches, A. M. Foda, S. Furletov, L. Gan, H. Gao, A. Gardener, A. Gasparian, D. I. Glazier, C. Gleason, V. S. Goryachev, B. Grube, J. Guo, L. Guo, J. Hernandez, K. Hernandez, N. D. Hoffman, D. Hornidge, G. Hou, P. Hurck, A. Hurley, W. Imoehl, D. G. Ireland, M. M. Ito, I. Jaegle, N. S. Jarvis, T. Jeske, M. Jing, R. T. Jones, V. Kakoyan, G. Kalicy, V. Khachatryan, C. Kourkoumelis, A. Laduke, I. Larin, D. Lawrence, D. I. Lersch, H. Li, B. Liu, K. Livingston, G. J. Lolos, L. Lorenti, V. Lyubovitskij, R. Ma, D. Mack, A. Mahmood, H. Marukyan, V. Matveev, M. Mccaughan, M. Mccracken, C. A. Meyer, R. Miskimen, R. E. Mitchell, K. Mizutani, V. Neelamana, L. Ng, E. Nissen, S. Oreśić, A. I. Ostrovidov, Z. Papandreou, C. Paudel, R. Pedroni, L. Pentchev, K. J. Peters, E. Prathr, S. Rakshit, J. Reinhold, A. Remington, B. G. Ritchie, J. Ritman, G. Rodriguez, D. Romanov, K. Saldana, C. Salgado, S. Schadmand, A. M. Schertz, K. Scheuer, A. Schick, A. Schmidt, R. A. Schumacher, J. Schwiening, N. Septian, P. Sharp, X. Shen, M. R. Shepherd, J. Sikes, A. Smith, E. S. Smith, D. I. Sober, A. Somov, S. Somov, J. R. Stevens, I. I. Strakovsky, B. Sumner, K. Suresh, V.V. Tarasov, S. Taylor, A. Teymurazyan, A. Thiel, T. Viducic, T. Whitlatch, N. Wickramaarachchi, Y. Wunderlich, B. Yu, J. Zarling, Z. Zhang, X. Zhou, B. Zihlmann

Physics Faculty Publications

We measure the spin-density matrix elements (SDMEs) of the Δ⁺⁺ (1232) in the photoproduction reaction 𝛾p→π−Δ⁺⁺(1232) with the GlueX experiment in Hall D at Jefferson Lab. The measurement uses a linearly–polarized photon beam with energies from 8.2 to 8.8 GeV and the statistical precision of the SDMEs exceeds the previous measurement by three orders of magnitude for the momentum transfer squared region below 1.4 GeV². The data are sensitive to the previously undetermined relative sign between couplings in existing Regge-exchange models. Linear combinations of the extracted SDMEs allow for a decomposition into natural and unnatural–exchange amplitudes. We find that the …

20 Years Of Light Pentaquark Searches, Moskov Amaryan

Physics Faculty Publications

In this paper, I pay tribute to my exceptional colleagues and friends Dmitri Diakonov, Victor Petrov, and Maxim Polyakov by examining the experimental progress and current status of the searches of the ϴ⁺ pentaquark from its inception to the present.

Isochronous And Period-Doubling Diagrams For Symplectic Maps Of The Plane, T. Zolkin, S. Nagaitsev, I. Morozov, S. Kladov, Y. -K. Kim

Physics Faculty Publications

Symplectic mappings of the plane serve as key models for exploring the fundamental nature of complex behavior in nonlinear systems. Central to this exploration is the effective visualization of stability regimes, which enables the interpretation of how systems evolve under varying conditions. While the area-preserving quadratic Hénon map has received significant theoretical attention, a comprehensive description of its mixed parameter-space dynamics remain lacking. This limitation arises from early attempts to reduce the full two-dimensional phase space to a one-dimensional projection, a simplification that resulted in the loss of important dynamical features. Consequently, there is a clear need for a more …

Preparation Of Mocvd-Grown Photocathodes Containing A Strained Gaas/Gaasp Superlattice, G. Blume, A. Masters, J. Grames, M. Stutzman, M. Grau, S. Marsillac

Physics Faculty Publications

In this work, we investigate heat cleaning options for high-polarization GaAs/GaAsP strained-superlattice (SSL) photocathodes with a distributed Bragg reflector (DBR) that were grown using metalorganic chemical vapor deposition (MOCVD). This was done using a microMott polarimeter at Jefferson Lab to optimize both quantum efficiency and polarization. The fabrication process for MOCVD-grown photocathodes does not allow for the inclusion of an arsenic cap, contrary to what is done when fabricating photocathodes using molecular-beam epitaxy (MBE). Without proper preparation, the performance of MOCVD-grown photocathodes can be limited due to surface contamination. Here, we varied both duration and temperature of the heat cleaning …

First Measurement Of Near-Threshold And Subthreshold J/Ѱ Photoproduction Off Nuclei, J. R. Pybus, L. Ehinger, T. Kolar, B. Devkota, P. Sharp, B. Yu, M. M. Dalton, D. Dutta, H. Gao, O. Hen, E. Piasetzky, S. N. Santiesteban, A. Schmidt, A. Somov, H. Szumila-Vance, S. Adhikari, A. Asaturyan, A. Austregesilo, C. Ayerbe Gayoso, J. Barlow, V. V. Berdnikov, H. D. Bhatt, D. Bhetuwal, T. Black, W. J. Briscoe, G. Chung, P. L. Cole, A. Deur, R. Dotel, H. Egiyan, P. Eugenio, C. Fanelli, L. Gan, A. Gasparian, J. Guo, K. Hernandez, D. W. Higinbotham, P. Hurck, I. Jaegle, R. T. Jones, V. Kakoyan, A. Karki, H. Li, W. B. Li, G. R. Linera, V. Lyubovitskij, H. Marukyan, M. D. Mccaughan, M. Mccracken, K. Mizutani, D. Nguyen, S. Oresic, A. I. Ostrovidov, Z. Papandreou, C. Paudel, K. Peters, J. Ritman, A. Schick, J. Schwiening, A. Smith, S. Somov, I. Strakovsky, K. Suresh, V. V. Tarasov, S. Taylor, T. Xiao, Z. Zhang, X. Zhou

Physics Faculty Publications

We report on the first measurement of J/ψ photoproduction from nuclei in the photon energy range of 7 to 10.8 GeV, extending above and below the photoproduction threshold in the free proton of ∼8.2 GeV. The experiment used a tagged photon beam incident on deuterium, helium, and carbon, and the GlueX detector at Jefferson Lab to measure the semi-inclusive A(γ,e⁺e^-p) reaction with a dilepton invariant mass M(e⁺e^-)∼m_J/ψ=3.1 GeV. The incoherent J/ψ photoproduction cross sections in the measured nuclei are extracted as a function of the incident photon energy, momentum transfer, …

Measurement Of The Total Compton Scattering Cross Section Between 6.5 And 11 Gev, The Gluex Collaboration, F. Afzal, C. S. Akondi, M. Albrecht, M. Amaryan, S. Arrigo, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barriga, R. Barsotti, D. Barton, V. Baturin, V. V. Berdnikov, T. Black, W. Boeglin, M. Boer, W. J. Briscoe, T. Britton, R. Brunner, S. Cao, E. Chudakov, G. Chung, P. L. Cole, O. Cortes, V. Crede, M. M. Dalton, D. Darulis, A. Deur, S. Dobbs, A. Dolgolenko, M. Dugger, R. Dzhygadlo, D. Ebersole, M. Edo, T. Erbora, P. Eugenio, A. Fabrizi, C. Fanelli, S. Fang, M. Fritsch, S. Furletov, L. Gan, H. Gao, A. Gardner, A. Gasparian, D. I. Glazier, G. Gleason, V. S. Goryachev, B. Grube, J. Guo, L. Guo, J. Hernandez, K. Hernandez, N. D. Hoffman, D. Hornidge, G. M. Huber, P. Hurck, W. Imoehl, D. G. Ireland, M. M. Ito, I. Jaegle, N. S. Jarvis, T. Jeske, M. Jing, R. T. Jones, V. Kakoyan, G. Kalicy, V. Khachatryan, C. Kourkoumelis, A. Laduke, I. Larin, D. Lawrence, D. I. Lersch, H. Li, B. Liu, K. Livingston, L. Lorenti, V. Lyubovitskij, A. Mahmood, H. Marukyan, V. Matveev, M. Mccaughan, M. Mccracken, C. A. Meyer, R. Miskimen, R. E. Mitchell, K. Mizutani, P. Moran, V. Neelamana, L. Ng, E. Nissen, S. Orei, A. I. Ostrovidov, Z. Papandreou, C. Paudel, R. Pedroni, L. Pentchev, K. J. Peters, E. Prather, L. Puthiya Veetil, S. Rakshit, J. Reinhold, A. Remington, B. G. Ritchie, J. Ritman, G. Rodriguez, D. Romanov, K. Saldana, C. Salgado, S. Schadmand, A. M. Schertz, K. Scheuer, A. Schick, A. Schmidt, R. A. Schumacher, J. Schwiening, M. Scott, N. Septian, P. Sharp, V. J. Shen, X. Shen, M. R. Shepherd, J. Sikes, H. Singh, A. Smith, E. S. Smith, D. I. Sober, A. Somov, S. Somov, J. R. Stevens, I. I. Strakovsky, B. Sumner, K. Suresh, V. V. Tarasov, S. Taylor, A. Teymurazyan, A. Thiel, M. Thomson, T. Viducic, T. Whitlatch, N. Wickramaarachchi, Y. Wunderlich, B. Yu, J. Zarling, Z. Zhang, X. Zhou, B. Zihlmann

Physics Faculty Publications

The total cross section for Compton scattering off atomic electrons, γ + e→γ′+e′, was measured using photons with energies between 6.5 and 11.1 GeV incident on a ⁹Be target as part of the PrimEx-eta experiment in Hall D at Jefferson Lab. This is the first measurement of this fundamental QED process within this energy range. The total uncertainties of the cross section, combining the statistical and systematic components in quadrature, averaged to 3.4 % across all energy bins. This not only demonstrates the capability of this experimental setup to perform precision cross-section measurements at forward angles but also allows us …

Multidimensional Measurements Of Beam Single-Spin Asymmetries In Semi-Inclusive Deep-Inelastic Charged-Kaon Electroproduction Off Protons In The Valence Region, Clas Collaboration, A. Kripko, S. Diehl, K. Joo, P. Achenbach, J. S. Alvarado, M. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, L. Baashen, N. A. Baltzell, L. Barion, L. Bashkanov, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, K. -T. Brinkmann, W. J. Briscoe, W. K. Brooks, T. Cao, R. Capobianco, D. S. Carman, J. C. Carvajal, A. Celentano, P. Chatagnon, G. Ciullo, P. L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Dilks, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, S. Fegan, I. P. Fernando, A. Filippi, G. Gavalian, G. P. Gilfoyle, D. I. Glazier, R. W. Gothe, Y. Gotra, K. Hafidi, H. Hakobyan, M. Hattawy, F. Hauenstein, T. B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D. G. Ireland, E. L. Isupov, H. Jiang, H. S. Jo, T. Kageya, A. Kim, W. Kim, V. Klimenko, V. Kubarovsky, S. E. Kuhn, L. Lanza, P. Lenisa, X. Li, Z. Lu, I. J. D. Macgregor, D. Marchand, D. Martiryan, V. Mascagna, D. Matamoros, M. Maynes, B. Mckinnon, R. G. Milner, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, P. Nadel-Turonski, T. Nagorna, K. Neupane, D. Nguyen, S. Niccolai, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, L. L. Pappalardo, R. Paremuzyan, E. Pasyuk, S. J. Paul, N. Pilleux, S. Polcher Rafael, J. Poudel, J. W. Price, Y. Prok, T. Reed, M. Ripani, J. Ritman, C. D. Roberts, P. Rossi, A. A. Rusova, S. Schadmand, A. Schmidt, Y. G. Sharabian, E. V. Shirokov, S. Shrestha, U. Shrestha, D. Sokhan, N. Sparveris, M. Spreafico, I. I. Strakovsky, S. Strauch, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, T. Vittorini, H. Voskanyan, A. Vossen, E. Voutier, Y. Wang, D. P. Watts, U. Weerasinghe, X. Wei, M. H. Wood, L. Xu, S. -S. Xu, N. Zachariou, V. Ziegler, M. Zurek

Physics Faculty Publications

Measurements of beam single-spin asymmetries in semi-inclusive deep-inelastic electron scattering (SIDIS) with positively charged kaons off protons have been performed with 10.6 and 10.2 GeV incident electron beams using the CLAS12 spectrometer at Jefferson Lab. We report an analysis of the electroproduction of positively charged kaons over a large kinematic range of fractional energy, Bjorken x, transverse momentum, and photon virtualities Q² ranging from 1 GeV² up to 6 GeV². This is the first published multidimensionally binned CLAS12 measurement of a kaon SIDIS single-spin asymmetry in the valence quark regime. The data provide constraints on the structure function ratio …

Low-Charge, High-Resolution Beamline Preparation For The Nanopatterned Microbunching Experiment At Argonne Wakefield Accelerator, R. Margraf-O'Neal, A. Ody, J. Power, J. Hlavenka, B. N. Temizel Ozdemir, G. Andonian, B. Carlsten, A. Desimone, G. Ha, A. Halavanau, H. Xu, N. Majernik, J. M. Maxson, A. Parrack, R. Ryne, M. Yadav, N. Yampolsky, J. Rosenzweig

Physics Faculty Publications

The emittance exchange (EEX) beamline at the Argonne Wakefield Accelerator (AWA) is designed to transfer properties of an electron beam phase space between the transverse and longitudinal planes. Recently, it has been proposed this beamline could be used to convert a microscale transverse modulation created by a TEM grid into a microbunch train in the longitudinal plane. Such a technique would be useful for obtaining nano-scale microbunching that does not rely on the sensitive process of FEL gain. This new approach has been proposed to enable development of a compact free-electron laser at Arizona State, greatly reducing size and cost …

First Global Extraction Of Generalized Parton Distributions From Experiment And Lattice Data With Next-To-Leading-Order Accuracy, Yuxun Guo, Fatma P. Aslan, Xiangdong Ji, M. Gabriel Santiago

Physics Faculty Publications

We report the first global extraction of generalized parton distributions, GUMP 1.0, by combining deeply virtual Compton scattering and ρ-meson production data from Jefferson Lab and the Hadron-Electron Ring Accelerator with global fits of parton distribution functions, charge form factors, and lattice quantum chromodynamics simulations. Using a conformal moment space parametrization, we achieve a unified description across low- and high-x regions at next to leading order accuracy in perturbative corrections. The results provide state-of-the-art generalized parton distributions consistent with almost all known facts, enabling three-dimensional nucleon imaging in impact parameter space and, at the same time, establishing a benchmark for …

The Goddard Rocket Researches: A Photographic Record, Esther C. Goddard

The Goddard Rocket Researches: A Photographic Record [Photo Album]

This page contains a pdf scan of 'The Goddard Rocket Researches: A Photographic Record' in its entirety. The individual photographs and their descriptions can be seen here.

'The Goddard Rocket Researches: A Photographic Record' is an annotated photo album covering Robert H. Goddard's work and experimentation with rocketry. It was assembled and curated by Esther Goddard sometime after her husband's passing in 1945.

The vast majority of these photographs were taken by Esther herself. Esther was an avid camerawoman and photographer, and during Robert's lifetime she meticulously documented his life's work in rocketry--from experiments and instruments to processes and …

Elucidating The Role Of Hydrogen At C-In2o3/A-In2o3−X Interface, Julia E. Medvedeva, Mariana I. Bertoni

Physics Faculty Research & Creative Works

Ab initio molecular dynamics simulations and hybrid functional electronic structure calculations are employed to determine the formation, the structural and electronic properties, and the dynamics of covalent (In-OH) and ionic (In-H-In) hydrogen defects at crystalline-In2O3/amorphous-In2O3−x interface. This comprehensive computational study considers (i) various interstitial and substitutional hydrogen site locations within the crystalline, amorphous, and interfacial regions; (ii) several oxygen-to-hydrogen ratios; and (iii) possible defect charged states. The results reveal hydrogen's inability to fully passivate the undercoordinated under-shared in atoms in amorphous highly substoichiometric oxide, giving rise to the formation of deep electron traps even in net-charge neutral structures. These trap …

Mathematics And Determinism: Chaos, Quantum Mechanics, And The Limits Of Predictive Structure, Jackson T. Salumbides

CMC Senior Theses

This thesis examines the relationship between mathematics and determinism by analyzing how chaos theory, quantum mechanics, and formal mathematical limits challenge traditional conceptions of predictability and causal structure. Chaos theory shows that deterministic systems can exhibit practical unpredictability due to sensitivity to initial conditions. Quantum mechanics introduces probabilistic outcomes that complicate deterministic interpretation, though alternative frameworks such as Bohmian mechanics and superdeterminism attempt to restore determinism at conceptual cost. Additionally, results from mathematical logic, including Gödel’s incompleteness theorems and Turing’s undecidability, demonstrate intrinsic limitations on what can be deduced or computed, even in fully deterministic systems. By synthesizing these areas, …

The Organization Of Serotonergic Fibers In The Pacific Angelshark Brain: Neuroanatomical And Supercomputing Analyses, Skirmantas Janušonis, Ralf Metzler, Thomas Vojta

Physics Faculty Research & Creative Works

Serotonergic axons (fibers) are a universal feature of all vertebrate brains. They form meshworks, typically quantified with regional density measurements, and appear to support neuroplasticity. The self-organization of this system remains poorly understood, partly because of the strong stochasticity of individual fiber trajectories. In an extension to our previous analyses of the mouse brain, serotonergic fibers were investigated in the brain of the Pacific angel shark (Squatina californica), a representative of a unique (ray-like) lineage of the squalomorph sharks. First, the fundamental cytoarchitecture of the angel shark brain was examined, including the expression of ionized calcium-binding adapter molecule 1 (Iba1, …

Drag Reduction In Ground Vehicles Using A Model Porous Medium, Abdullah Ikram Nabi

Master’s Theses

This research investigates aerodynamic drag reduction on a 25° Slanted Ahmed Body (SAB) by integrating porous media model rods through combined experimental and computational methods at a Reynolds number of 1.16×10⁴. Two porous media configurations: short rods (6.75% of the model height) and long rods (20.0% of the model height), both featuring cylindrical rods with 80% porosity, were systematically compared against a baseline SAB. In-depth analyses were performed to investigate the wake flow topology, recirculation region characteristics, pressure coefficient distribution, Reynolds stress distributions and drag coefficient. Experimental investigations employed particle image velocimetry for precise flow visualization, while Reynold Averaged Navier-Stokes …

Scaling Laws For Diffusion In Crystallized Plasma From Molecular Dynamics, Dany Yaacoub

Theses and Dissertations

Diffusion coefficients for crystallized Coulomb plasmas are essential microphysics input for modeling white dwarf cores and neutron star crusts. Solving for diffusion coefficients require running large molecular dynamics simulations with thousands of particles over millions of timesteps. The diffusion in a crystallized plasma has been largely ignored and is often taken to be zero in stellar evolution codes. We find that not only is this incorrect, but we find that the diffusion in a crystallized plasma can be modeled completely using a universal scaling law independent of screening. Our simulations also show that the dominant mode of diffusion in a …

High Antarctic Coastal Productivity In Polynyas Revealed By Considering Remote Sensing Ice-Adjacency Effects, Hilde Oliver, Jessica S. Turner, Alexandre Castagna, Henry Houskeeper, Heidi Dierssen

OES Faculty Publications

Ocean color-based estimates of Antarctic net primary productivity (NPP) have indicated low nearshore productivity in ice-adjacent waters, contrasting with coupled physical–biogeochemical models. To understand this discrepancy, we assessed satellite records of polynya NPP by comparing field data with two satellite imagery datasets derived using different processing schemes. Our results indicate historical underestimation of chlorophyll a for imagery obtained using default atmospheric correction processing within approximately 100 km of ice-covered coastlines due to adjacency effects. Using radiative transfer modeling, we find that biases in ocean color polynya observations due to adjacency effects correspond to the high albedo of ice and snow. …

First-Principles Study Of The Heterostructure, Znsb Bilayer/H-Bn Monolayer For Thermoelectric Applications, Zakariae Darhi, Larbi El Farh, Ravindra Pandey

Michigan Tech Publications

ZnSb is widely recognized as a promising thermoelectric material in its bulk form, and a ZnSb bilayer was recently synthesized from the bulk. In this study, we designed a vertical van der Waals heterostructure consisting of a ZnSb bilayer and an h-BN monolayer to investigate its electronic, elastic, transport, and thermoelectric properties. Based on density functional theory, the results show that the formation of this heterostructure significantly enhances electron mobility and reduces the bandgap compared to the ZnSb bilayer, thereby increasing its power factor. These findings highlight the potential of the h-BN monolayer–supported ZnSb bilayer heterostructure in thermoelectric applications, where …

Quantifying The Performance Of The Sparta Toolkit For Use In Planetary Regolith Characterization Missions, Abigail S. Glover

Honors Undergraduate Theses

This research investigates the use of the Soil Properties Assessment, Resistance, and Thermal Analysis (SPARTA) Cone Penetration Tester (CPT) to quantify bulk density in lunar regolith simulant LHS-1E. Twenty-five penetration tests were conducted across five density profiles to derive slope parameters (G), which represent the rate of increase in resistance with depth. Results showed a consistent, nonlinear relationship between G and bulk density, validating the use of G slope as a diagnostic parameter and supporting the primary hypothesis that SPARTA CPT measurements vary meaningfully with density. Compared to prior work by Lucas et al. (2024), G values from SPARTA were …

Entangled Photoelectron Attosecond Spectroscopy, Jonathan Sar-Shalom

Honors Undergraduate Theses

In this thesis we propose an interferometric scheme to retrieve the dynamics of an electron wave packet emitted from two distinct residual photo-ion channels in the ionization of an atom by an ultra-short UV pulse. EPAS (Entangled-Photoelectron Attosecond Spectroscopy) works by having a non-overlapping UV and few-cycle IR pulse, where the IR is tuned near the transition frequency between two electronic bound states of the photo-ion. Using a time-dependent simulation based on a two-channel atomic model, supported by a perturbative approach, we were able to compute the resulting interference in the angular distribution of the photoelectron and retrieve the energy-dependent …

In Vitro Microfluidics System For Mechanobiologic Investigations, Michael A. Daanen

Honors Theses

Mechanobiology is an emerging field that aims to study the relationships between mechanical forces and cellular behavior. Such mechanobiological relationships are especially critical in the cardiovascular system, where endothelial cells lining the vasculature align in response to fluid shear stresses from blood flow (Sinha, 2016). Implanted flow devices, diabetes, chronic hypertension, and various other diseases and pathophysiologies alter vessel geometries and flow dynamics. Such alterations impact fluid shear stress and endothelial cell behavior, leading to microcirculatory dysfunction, vessel leakage, and organ failure (Poredos, 2021; Papadaki, 1999; Leitschuh, 1987). To simulate dysfunctional endothelial cell behavior in vitro and evaluate novel therapeutic …

Theoretical Study Of Phase-Ordering Kinetics With An Anisotropic Surface Tension, Arjun Anand, Ben Vollmayr-Lee

Honors Theses

Coarsening describes the phase-separation dynamics that follows after a temperature quench from a stable to unstable region of the phase diagram in binary systems. Whereas binary systems with an isotropic surface tension have been thoroughly examined and modeled, the case of an anisotropic surface tension lacks the same degree of analysis and development. In this thesis, we demonstrate the self-consistency of the scaling hypothesis with an anisotropic surface tension in the dilute limit. We begin by assuming weak anisotropy in the surface tension and working only to first order in perturbation theory. Following a similar approach laid out in the …

Scp 231 Dictionary + Example Problems [General Physics 1], Daniel Capic

Open Educational Resources

Student-written definitions of key physics concepts that appear in SCP 231. There are also student-written word problems with links to instructor-created video solutions.

Investigation Of Colorimetric Trends In Rare-Earth Co-Doped Ypo₄, Barit K. Essman

All Master's Theses

From detectors in scientific instrumentation to medical imaging devices and nuclear monitoring systems to LEDs seen in consumer products, phosphors are utilized in a myriad of applications experienced by both the general public and scientific community alike. For many phosphor applications, emission color and intensity are notably important features to consider. When phosphors are co-doped with rare-earth activators, the ability to predict emission intensity and color output becomes challenging due to competition kinetics and energy transfer between the dopants. During this study, correlation between trends in co-doped phosphor excitation and color output were analyzed to interpret optical behaviors originating from …