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Articles 1 - 29 of 29
Full-Text Articles in Physics
Understanding The Pressure-Sinkage Relationship For Simulated Lunar Regolith And Implications On Bearing Capacity And Trafficability, Catherine A. Millwater
Understanding The Pressure-Sinkage Relationship For Simulated Lunar Regolith And Implications On Bearing Capacity And Trafficability, Catherine A. Millwater
Honors Undergraduate Theses
The intent of this thesis is to explore the pressure-sinkage relationship for simulated lunar regolith (simulant). The simulants used in this experiment emulate the lunar highlands (LHS-1) and the lunar mare (LMS-1). The ultimate ability of a terrain or regolith to support a load without shear failure is vital to the planning and construction of permanent infrastructure. This relationship can be measured by applying a normal load to the regolith until shear failure, from which allowable and ultimate bearing capacity can be deduced. An understanding of the pressure-sinkage of lighter loads on the higher ‘fluffy' layer of regolith is of …
Observation Of Gapless Nodal-Lines In A Rare-Earth-Based Compound, Robert Smith
Observation Of Gapless Nodal-Lines In A Rare-Earth-Based Compound, Robert Smith
Honors Undergraduate Theses
This thesis aims to contribute to the understanding of quantum materials by employing a combination of experimental techniques, such as angle-resolved photoemission spectroscopy and magnetic and transport measurements. Further collaborative support in the form of first-principles calculations is included and discussed in tandem. In this thesis, a lanthanide-based semimetal of the ZrSiS type, is investigated. Multiple nodal lines which remain gapless are observed along the X-R direction of the Brillouin zone. We also present a nodal line that is observed further below the Fermi level and aligned in the G-M direction; this nodal line appears to be sensitive to light …
Osiris-Rex Surface Imaging To Constrain Properties Of The Asteroid (101955) Bennu, Alicia Allen
Osiris-Rex Surface Imaging To Constrain Properties Of The Asteroid (101955) Bennu, Alicia Allen
Honors Undergraduate Theses
This study used images taken from the OSIRIS-REx spacecraft sample-return mission and projected onto a three-dimensional shape model to determine surface properties of the asteroid (101955) Bennu. Two major projects were completed. For the first project, images of the pre-sampled Nightingale site and post-sampled Nightingale were compared to determine how the TAGSAM sampling maneuver effected the surface of the asteroid directly at the sampling site and in the surrounding area. This analysis demonstrated how spacecraft can potentially affect a small body during this and future sample-return missions. For the second project, several craters on Bennu’s surface were selected and all …
Impact Of Proton And Neutron Irradiation On Carrier Transport Properties In Ga2o3, Andrew C. Silverman
Impact Of Proton And Neutron Irradiation On Carrier Transport Properties In Ga2o3, Andrew C. Silverman
Honors Undergraduate Theses
This project studies the properties of minority charge carriers in beta gallium oxide (β -Ga2O3). The behavior of minority carriers is of high importance as it greatly affects conduction and consequently device performance. Cathodoluminescence (CL) spectroscopy and EBIC (Electron Beam Induced Current) are the main experimental techniques used to study minority carrier behavior.
High energy radiation affects minority carrier properties through damage to the material and through the production of carrier traps that reduce the conductivity and mobility of the material. In this investigation, we study the effects of various kinds of high energy radiation on …
Instanton Counting, Matrix Models, And Characters, Spencer Tamagni
Instanton Counting, Matrix Models, And Characters, Spencer Tamagni
Honors Undergraduate Theses
In this thesis we study symmetries of quantum field theory visible only at the non-perturbative level, which arise from large deformations of the integration contour in the path integral. We exposit the recently-developed theory of qq-characters that organizes such symmetries in the case of N = 2 supersymmetric gauge theories in four dimensions. We sketch the physical origin of such observables from intersecting branes in string theory, and the mathematical origin as certain
equivariant integrals over Nakajima quiver varieties. We explain some of the main applications, including the derivation of Seiberg-Witten geometry for quiver gauge theories and the relations to …
Heterogenous Reduction Of Co2 Over Boron-Rich Alb2, Jose C. Berger
Heterogenous Reduction Of Co2 Over Boron-Rich Alb2, Jose C. Berger
Honors Undergraduate Theses
Evidence suggests that the recent drastic changes in the global climate have been caused by greenhouse gases, especially CO2. As a result, scientists are aiming to develop processes that either minimize the production of these gases or convert them into products of higher value. To that end, the catalytic properties of a two-dimensional boron-rich material were investigated. Herein is reported that such a material can reduce CO2 into benzene, C3 species, and C4 species at relatively low temperatures (225-450 ℃) and pressures (0.38 MPa). Current data suggest that a low-temperature induction period (e.g., 225 ℃) …
Structure Of Unmodified And Pyroglutamylated Amyloid Beta Peptide In Lipid Membranes, Rowan Hassan
Structure Of Unmodified And Pyroglutamylated Amyloid Beta Peptide In Lipid Membranes, Rowan Hassan
Honors Undergraduate Theses
Alzheimer's Disease (AD) is a devastating neurodegenerative disease that is characterized by brain atrophy, neuronal and synaptic loss, cognitive decline, trouble handling activities of daily life, and ultimately leads to death. Worldwide, at least 30 million people suffer from AD, with 5.8 million suffering in the US alone. Despite extensive basic and clinical research, the underlying molecular mechanisms behind AD remain largely unknown. There are four FDA-approved compounds are used for alleviating symptoms but have no curative potency. The first potentially disease-modifying AD drug, aducanumb, was approved by FDA in June 2021. The main histopathological traits of AD are the …
Photoemission Investigation Of Topological Quantum Materials, Klauss M. Dimitri
Photoemission Investigation Of Topological Quantum Materials, Klauss M. Dimitri
Honors Undergraduate Theses
Topological insulators (TIs) are a class of quantum materials, which behave as insulators in the bulk, yet possess gapless spin-polarized surface states, which are robust against nonmagnetic impurities. The unique properties of TIs make them attractive not only for studying various fundamental phenomena in condensed matter and particle physics, but also as promising candidates for applications ranging from spintronics to quantum computation. Within the topological insulator realm, a great deal of focus has been placed on discovering new quantum materials, however, ideal multi-modal quantum materials have yet to be found. Here we study alpha-PdBi2, KFe2Te2, and DySb compounds including others …
Modeling And Analysis Of Covid-19 And Dynamical Systems In Biology And Physics, Vladimir Grbic
Modeling And Analysis Of Covid-19 And Dynamical Systems In Biology And Physics, Vladimir Grbic
Honors Undergraduate Theses
In this paper, we study various examples of dynamical systems found in nature and extract the necessary concepts to build upon. Then, we develop and propose a new deterministic model for COVID-19 propagation. Our model should serve two purposes. First, we will approximate the infected and deceased individuals after a given time during the pandemic. Then, using a linearized subsystem describing infectious compartments about the disease- free equilibrium (DFE), we will determine the basic reproductive number (R0) by the next-generation matrix method.
Molten Regolith Electrolysis Processing For Lunar Isru: Financial And Physics Analysis Of Spacex Starship Transportation, Cheyenne Harper
Molten Regolith Electrolysis Processing For Lunar Isru: Financial And Physics Analysis Of Spacex Starship Transportation, Cheyenne Harper
Honors Undergraduate Theses
The purpose of the following research is to explore molten regolith electrolysis (MRE) methodology for in-situ resource utilization (ISRU) of Highlands lunar regolith, to be explored during the initial Artemis missions. An analysis of potential commercial launch providers for MRE-equipment based on technology-readiness level (TRL), payload mass support, and $ USD/kg payload price is provided. SpaceX is ultimately proposed as a launch provider of MRE equipment following multi-factorial analysis, with the SpaceX Starship human landing system (HLS) variant proposed for supporting MRE payload. Finally, customers of regolith-derived oxygen, aluminum, and silicon are distinguished to form the business case for operating …
Analysis And Design Of Infrared Fiber Bundles For Large Field-Of-View Thermal Imaging, Cesar A. Lopez-Zelaya
Analysis And Design Of Infrared Fiber Bundles For Large Field-Of-View Thermal Imaging, Cesar A. Lopez-Zelaya
Honors Undergraduate Theses
During the DARPA SCENICC program, J. Ford, et al., demonstrated that CFBs provide a compelling route to compact, wide angle imagers. Monocentric lenses readily provide diffraction-limited images over wide field but onto a hemispherically curved image surface. They demonstrated visible CFBs can be tapered, cut and polished to relay curved images to flat sensors. We have shown that this provides a volumetric imaging efficiency a hundredfold larger than bulk optics can produce; a hundred times the resolution in the same volume or a hundred times less volume for the same resolution. Ford's work leveraged commercial fiber bundles available for the …
Predicting Structures Of 2d Materials Enabled By Machine Learning, Sonali Joshi
Predicting Structures Of 2d Materials Enabled By Machine Learning, Sonali Joshi
Honors Undergraduate Theses
Prediction of stable structures of two-dimensional (2D) materials that have not been experimentally realized is an important pre-requisite step for the development of these materials for various technological uses without the extensive trial-error experiments. Traditional methods such as density functional theory (DFT) can be used to find the energies of structures computationally, however, calculating the energies of the total number of structures possible would be daunting timewise as well. We propose using machine learning methods to reduce the search time for 2D materials’ geometric structures. Our case study for this process consists of hexagonal graphene-like boron–carbon–nitrogen (h-BCN). Our …
Characterization Of The Physical And Chemical Effect Of Membrane Disruption And Protein Inhibiting Treatments On E. Coli, Khadijah Wright
Characterization Of The Physical And Chemical Effect Of Membrane Disruption And Protein Inhibiting Treatments On E. Coli, Khadijah Wright
Honors Undergraduate Theses
The increase in antibacterial resistance has placed the issue of microbial multi-drug resistance on a global stage (Gurunathan, 2019). This issue poses a threat to human and animal health as well as to the environment (Aslam et al., 2018). It affects not only the efficacy of treatment but also how those treatments are conducted (Friedman, Temkin, & Carmeli, 2016). As a result of this ongoing threat, new treatments that have potent effects on bacteria are necessary. One scientific response to this issue has been the development of multifunctional nanoparticles (NPs)(H. Wang et al., 2018). NPs have the ability to be …
Polarization Dependence Of High Order Harmonic Generation From Solids In Reflection And Transmission Geometries, Erin L. Crites
Polarization Dependence Of High Order Harmonic Generation From Solids In Reflection And Transmission Geometries, Erin L. Crites
Honors Undergraduate Theses
High harmonic generation (HHG) is a process that occurs when an intense laser interacts with a material and generates new frequencies of light. HHG has many practical applications, namely as a spectroscopy technique and source for high frequency light and attosecond pulses. While HHG has been done extensively in gases, HHG in solids is a relatively new field. Solids are appealing as an HHG medium as they require much simpler equipment and are subsequently much more compact, and thus may have a variety of applications previously inaccessible to gas-phase HHG. However, the generation mechanism of HHG in solids has not …
Development Of Nonlocal Green-Kubo Formalism With Applications To Coupled Heat And Mass Transport, Kevin Fernando
Development Of Nonlocal Green-Kubo Formalism With Applications To Coupled Heat And Mass Transport, Kevin Fernando
Honors Undergraduate Theses
Nonlocal equations for coupled heat and mass transport are developed within the Green-Kubo formalism. Nonlocal thermal transport in Lennard-Jones solids is computed to establish the existence of semi-ballistic transport. Deviations from the diffusive theory are shown by comparing the Fourier transform of the response function from the nonlocal theory to that of the diffusive one. It is shown that the deviations from the local theory correspond to acoustic phonons, whose frequency dependence gives rise to the observed deviations from the local theory.
Grating Coupler For Surface Waves Based On Electrical Displacement Currents, Jonathan R. Brescia
Grating Coupler For Surface Waves Based On Electrical Displacement Currents, Jonathan R. Brescia
Honors Undergraduate Theses
Bound electromagnetic surface waves can be excited by free-space waves on a corrugated conduction surface. These electromagnetic surface waves, called surface plasmon polaritons (SPPs), are coupled to a plasma of free charges, which travel together with the wave. We investigated the effect of separating metal corrugations from the smooth metal ground plane with a thin dielectric layer and show that SPPs can be excited via displacement currents. However, the SPP excitation resonances broaden and disappear as the dielectric thickness approaches 1% of the wavelength.
Structure Difference And Implication To Assembly Morphology Control Of Rous Sarcoma Virus Capsid Protein, John Hastings
Structure Difference And Implication To Assembly Morphology Control Of Rous Sarcoma Virus Capsid Protein, John Hastings
Honors Undergraduate Theses
Rous Sarcoma Virus (RSV) is an avian retrovirus with an enclosing capsid protein (CA) shell. RSV CA is studied due to its similar molecular structure to other retrovirus capsid proteins such as Human Immunodeficiency Virus (HIV). In this project, turbidity assay is used to track the assembly process of RSV CA, while solid state nuclear magnetic resonance (ssNMR) is used to probe the CA structure at a site specific level and investigate the morphology of the spherical structure of the I190V mutated strain of RSV CA. The I190V mutant is a naturally occurring mutation and is able to form into …
Climate Modeling, Outgoing Longwave Radiation, And Tropical Cyclone Forecasting, Thomas Rechtman
Climate Modeling, Outgoing Longwave Radiation, And Tropical Cyclone Forecasting, Thomas Rechtman
Honors Undergraduate Theses
Climate modeling and tropical cyclone forecasting are two significant is- sues that are continuously being improved upon for more accurate weather forecasting and preparedness. In this thesis, we have studied three climate models and formulated a new model with a view to determine the outgoing longwave radiation (OLR) budget at the top of the atmosphere (TOA) as ob- served by the National Oceanic and Atmospheric Administration’s (NOAA) satellite based Advanced Very High Resolution Radiometer (AVHRR). In 2006, Karnauskas proposed the African meridional OLR as an Atlantic hur- ricane predictor, the relation was further proven in 2016 by Karnauskas and Li …
Resonant Anisotropic Emission In Rabbitt Spectroscopy, Bejan M. Ghomashi
Resonant Anisotropic Emission In Rabbitt Spectroscopy, Bejan M. Ghomashi
Honors Undergraduate Theses
A variant of RABBITT pump-probe spectroscopy in which the attosecond pulse train comprises both even and odd harmonics of the fundamental IR probe frequency is explored to measure time-resolved photoelectron emission in systems that exhibit autoionizing states. It is shown that the group delay of both one-photon and two-photon resonant transitions is directly encoded in the energy-resolved photoelectron anisotropy as a function of the pump-probe time-delay. This principle is illustrated for a 1D model with symmetric zero-range potentials that supports both bound states and shape-resonances. The model is studied using both perturbation theory and solving the time-dependent Schodinger equation on …
Temperature Dependence Of Dynamical Spin Injection In A Superconducting Niobium Thin Film, Tyler S. Townsend
Temperature Dependence Of Dynamical Spin Injection In A Superconducting Niobium Thin Film, Tyler S. Townsend
Honors Undergraduate Theses
Spintronics is a research field that focuses on the manipulation of the quantum mechanical spin of charge carriers in solid state materials for future technological applications. Creating large spin currents with large relaxation times is sought after in the field of spintronics which may be aided by combining spintronics with superconductivity. This thesis provides a phenomological study of the effective change in ferromagnetic resonance linewidth, by dynamical spin injection into a permalloy-copper-niobium tri-layer in the superconducting state. The ferromagetic resonance linewidth was measured from 2-14 K. It was observed that there was a change in the behavior of the resonance …
Development Of A Compact Broadband Optical Parametric Oscillator For Ultra-Sensitive Molecular Detection, Sean O. Crystal
Development Of A Compact Broadband Optical Parametric Oscillator For Ultra-Sensitive Molecular Detection, Sean O. Crystal
Honors Undergraduate Theses
Every gas molecule has a unique absorption spectrum that can be captured using optical spectroscopy to identify an unknown sample's composition. Frequency combs systems can provide an extremely broad mid-infrared spectrum that is very useful for molecular detection. A degenerate optical parametric oscillator (OPO) was built to generate the down-converted and shifted frequency comb spectrum. This system utilizes an ultra-short pulse 1.56µm pump laser and a never before used orientation patterned gallium-phosphide crystal. Periodically polled lithium niobate (PPLN), Gallium Arsenide (GaAs) and Gallium Phosphide are all crystals used to accomplish this task. GaP, in comparison to PPLN, has (i) a …
Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera
Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera
Honors Undergraduate Theses
In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 μm in the lateral and 3.6 μm in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single …
Using Low-Coherence Interferometry To Monitor Cell Invasion In An In-Vitro Model System, Behnaz Davoudi Nasab
Using Low-Coherence Interferometry To Monitor Cell Invasion In An In-Vitro Model System, Behnaz Davoudi Nasab
Honors Undergraduate Theses
In an optically random system, such as naturally occurring and man-made media, light undergoes pronounced multiple scattering. This phenomenon has shown a remarkable potential in characterizing complex materials. In this regime, scattering occurs from each individual center of the scattering and independent scattering events lead to multiple light scattering. This phenomenon is often described as a random walk of photons and can be modeled in terms of a diffusion equation based on the radiative transfer theory. In this thesis, we used optical path-length spectroscopy (OPS), which is an experimental method to obtain the path-length probability density of the propagating light …
Power Distribution Of Terahertz Emission From Hexagonal Bscco Microstrip Antennas, Andrew E. Davis
Power Distribution Of Terahertz Emission From Hexagonal Bscco Microstrip Antennas, Andrew E. Davis
Honors Undergraduate Theses
We analyze the distribution of coherent terahertz radiation from a regular hexagonal microstrip antenna (MSA) made from the high-Tc superconductor Bi2Sr2CaCu2O8+x (BSCCO). We discuss the C6v symmetry of the solutions of the wave equation on a hexagonal domain and distinguish between the closed-form and non-closed-form solutions. The closed-form wavefunctions of the transverse magnetic (TM) electromagnetic cavity modes are presented and formulas for the radiated power arising from the uniform part of the AC Josephson current and from the resonant cavity modes are derived. The wavefunctions and angular distribution of radiation from …
Plasma Temperature Measurements In The Context Of Spectral Interference, Brandon Seesahai
Plasma Temperature Measurements In The Context Of Spectral Interference, Brandon Seesahai
Honors Undergraduate Theses
The path explored in this thesis is testing a plasma temperature measurement approach that accounts for interference in a spectrum. The Atomic Emission Spectroscopy (AES) technique used is called Laser Induced Breakdown Spectroscopy (LIBS) and involves focusing a laser pulse to a high irradiance onto a sample to induced a plasma. Spectrally analyzing the plasma light provides a "finger print" or spectrum of the sample. Unfortunately, spectral line broadening is a type of interference encountered in a LIBS spectrum because it blends possible ionic or atomic transitions that occur in plasma. To make use of the information or transitions not …
Flame-Turbulence Interaction For Deflagration To Detonation, Jessica Chambers
Flame-Turbulence Interaction For Deflagration To Detonation, Jessica Chambers
Honors Undergraduate Theses
Detonation is a high energetic mode of pressure gain combustion that exploits total pressure rise to augment high flow momentum and thermodynamic cycle efficiencies. Detonation is initiated through the Deflagration-to-Detonation Transition (DDT). This process occurs when a deflagrated flame is accelerated through turbulence induction, producing shock-flame interactions that generate violent explosions and a supersonic detonation wave. There is a broad desire to unravel the physical mechanisms of turbulence induced DDT. For the implementation of efficient detonation methods in propulsion and energy applications, it is crucial to understand optimum turbulence conditions for detonation initiation. The study examines the role of turbulence-flame …
Coherent Beam Combining Of Ultrashort Laser Pulses, Ahmad Azim
Coherent Beam Combining Of Ultrashort Laser Pulses, Ahmad Azim
Honors Undergraduate Theses
Ultrashort pulsed lasers have become critical to understanding light-matter interactions in new regimes such as generation of attosecond pulses, laser filamentation, and intense relativistic processes. Development of more powerful and energetic ultrafast lasers is required for advancing these fields of study. Several petawatt class systems now exist with more in development to further scale peak power and extend the frontier of ultrafast laser technology. Another relevant solution to the scaling of energy and power of ultrashort pulses is coherent beam combining (CBC). CBC is useful for not only scaling of laser parameters but also to mitigate parasitic nonlinear processes associated …
The Effect Of Impurities On The Superconductivity Of Bscco-2212, John Vastola
The Effect Of Impurities On The Superconductivity Of Bscco-2212, John Vastola
Honors Undergraduate Theses
BSCCO-2212 is a high-temperature cuprate superconductor whose microscopic behavior is currently poorly understood. In particular, it is unclear whether its order parameter is consistent with s-wave or d-wave symmetry. It has been suggested that its order parameter might take one of several forms that are consistent with d-wave behavior. We present some calculations using the many-body theory approach to superconductivity that suggest that such order parameters would lead to a suppression of the critical temperature in the presence of impurities. Because some experiments have suggested the critical temperature of BSCCO-2212 is relatively independent of the concentration of impurities, this lends …
An Improved Tight-Binding Model For Phosphorene, Kursti Delello
An Improved Tight-Binding Model For Phosphorene, Kursti Delello
Honors Undergraduate Theses
The intent of this thesis is to improve upon previously proposed tight-binding models for one dimensional black phosphorus, or phosphorene. Previous models offer only a qualitative analysis of the band structure of phosphorene, and fail to fully realize critical elements in the electronic band structure necessary for transport calculations. In this work we propose an improved tight-binding model for phosphorene by including up to eight nearest-neighbor interactions. The efficacy of the model is verified by comparison with DFT-HSE06 calculations, and the anisotropy of the effective masses in the armchair and zigzag directions is considered.