City College of New York
University of Arkansas, Fayetteville
Virginia Commonwealth University
Department of Physics, Utah State University
Albany State University
Liberty University
University of Pennsylvania
Understanding Students’ Global Interdependence In Science Instruction,
2021
Texas Tech University
Understanding Students’ Global Interdependence In Science Instruction, Walter S. Smith
Journal of Global Education and Research
Multiple American educational organizations such as the National Education Association, Association for Supervision and Curriculum Development, and the Council of Chief State School Officers have advocated for globalizing the K-12 curriculum. The National Science Teaching Association (NSTA) in a position statement on international education and the Next Generation Science Standards have produced goals and standards for internationalizing the science curriculum by addressing topics such as climate change, environment, and disease that cross borders. In contrast to those pronouncements on the curriculum, this article views global science education through an instructional lens that focuses on a students’ global interdependence in science ...
Stay Calm And Focus On The Learning Outcomes: Tools For Taking Biophysical Chemistry Online,
2021
Nova Southeastern University
Stay Calm And Focus On The Learning Outcomes: Tools For Taking Biophysical Chemistry Online, Maria Ballester, Brian L. Van Hoozen Jr., Arthur Sikora
Chemistry and Physics Faculty Articles
Course specific learning outcomes are an important tool to define the scope of a course and can be very helpful when designing experiments and assessments. With slight modification, these learning outcomes can serve as a guide when transitioning to the distance learning format especially in courses with a traditional lab. Here we present such an example for the biophysical chemistry course.
On-Chip Nanoscale Plasmonic Optical Modulators,
2021
American University in Cairo
On-Chip Nanoscale Plasmonic Optical Modulators, Abdalrahman Mohamed Nader Abdelhamid
Theses and Dissertations
In this thesis work, techniques for downsizing Optical modulators to nanoscale for the purpose of utilization in on chip communication and sensing applications are explored. Nanoscale optical interconnects can solve the electronics speed limiting transmission lines, in addition to decrease the electronic chips heat dissipation. A major obstacle in the path of achieving this goal is to build optical modulators, which transforms data from the electrical form to the optical form, in a size comparable to the size of the electronics components, while also having low insertion loss, high extinction ratio and bandwidth. Also, lap-on-chip applications used for fast diagnostics ...
Clustering And Halo Abundances In Early Dark Energy Cosmological Models,
2021
Swarthmore College
Clustering And Halo Abundances In Early Dark Energy Cosmological Models, A. Klypin, V. Poulin, F. Prada, J. Primack, M. Kamionkowski, V. Avila-Reese, A. Rodriguez-Puebla, P. Behroozi, D. Hellinger, Tristan L. Smith
Physics & Astronomy Faculty Works
Cold Dark Matter with cosmological constant (ΛCDM) cosmological models with early dark energy (EDE) have been proposed to resolve tensions between the Hubble constant H0=100h km ṡ−1Ṁpc−1 measured locally, giving h ≈ 0.73, and H0 deduced from Planck cosmic microwave background (CMB) and other early-Universe measurements plus ΛCDM, giving h ≈ 0.67. EDE models do this by adding a scalar field that temporarily adds dark energy equal to about 10 per cent of the cosmological energy density at the end of the radiation-dominated era at redshift z ∼ 3500. Here, we compare linear and non-linear predictions of a ...
Skyrmions And Biskyrmions In Magnetic Films,
2021
The Graduate Center, City University of New York
Skyrmions And Biskyrmions In Magnetic Films, Daniel Capic
Dissertations, Theses, and Capstone Projects
Skyrmions have garnered significant attention in condensed matter systems in recent years. In principle, they are topologically protected, so there is a large energy barrier preventing their annihilation. Furthermore, they can exist at the nanoscale, be manipulated with very small currents, and be created by a number of different methods. This makes them attractive for use in potential computing applications. This work studies ferromagnetic skyrmions. In particular, it highlights our small contributions to the field of skyrmions in condensed matter systems, specifically in thin-film ferromagnets.
Development Of A Diamond Defect Quantum Sensing Platform For Probing Novel Quantum Magnetic Phases,
2021
Washington University in St. Louis
Development Of A Diamond Defect Quantum Sensing Platform For Probing Novel Quantum Magnetic Phases, Jeffrey Ahlers
Senior Honors Papers / Undergraduate Theses
Nitrogen vacancy centers in diamond are highly effective quantum sensors due to their high spatial resolution and high magnetic field sensitivity. We present the construction of an optically detected magnetic resonance platform in order to facilitate the probing of magnetic phases in two-dimensional heterostructures. This includes the characterization of the required microwave voltage controlled oscillator and amplifier. In the presence of crystal strain, we measure ensemble nitrogen vacancy spin transitions with and without an applied magnetic field, and observe frequency shifts consistent with sample heating.
Characterization Of Landslide Processes From Radar Remote Sensing And Hydromechanical Modeling,
2021
Southern Methodist University
Characterization Of Landslide Processes From Radar Remote Sensing And Hydromechanical Modeling, Yuankun Xu
Earth Sciences Theses and Dissertations
Landsides are a natural geomorphic process yet a dangerous hazard which annually causes thousands of casualties and billions of property loss in a global scale. Understanding landslide motion kinematics from early initiation to final deposition is critical for monitoring, assessing, and forecasting landslide movement in order to mitigate their hazards. Landslides occur under diverse environmental settings and appear in variable types; however, all types of landslides can be mechanically attributed to shearing failure at the basal surface due to stress regime shift contributed by internal and/or external forcing. Typical internal factors include soil/rock weathering, whereas typical external triggering ...
Sampling Candidate Reionization Galaxies Using Spectral Energy Distribution Fitting,
2021
Macalester College
Sampling Candidate Reionization Galaxies Using Spectral Energy Distribution Fitting, Nicholas J. Velikonja, Michael Rutkowski
Macalester Journal of Physics and Astronomy
The process of reionization is one of the major pieces of galaxy evolution which remain to be un- derstood. With new observational tools like JWST on the horizon, imaging reionization-era galaxies will soon be possible. However, because the ionizing radiation is absorbed by the neutral hydrogen it ionizes, observers need some other parameter by which to identify those galaxies capable of reionizing. The search for ionizing emission via related parameters is well underway, and has come up with some tentative correlations, yet a consistent indicator or set of indicators remains to be discovered. New data in the Low-Redshift Lyman Continuum ...
Laser-Excitation Spectroscopy Of Niobium Hydride And Tantalum Hydride,
2021
Macalester College
Laser-Excitation Spectroscopy Of Niobium Hydride And Tantalum Hydride, Siddhant Singh
Macalester Journal of Physics and Astronomy
The experimental results presented in this paper shed light on some of the fundamental bonding characteristics of NbH and TaH. Six bands of niobium hydride and five weak bands of tantalum hydride were observed for the first time using laser excitation spectroscopy. The rotational assignments of observed bands were confirmed using dispersed fluorescence experiments for NbH and by checking the internal consistency of a global least squares fit for the weaker bands of TaH. For TaH, we were able to determine the term energies and molecular constants of each of its observed states to a high degree of accuracy by ...
Carrier Lifetime And Carrier Mobility Of Gaasn With Changing Nitrogen Concentration,
2021
Macalester College
Carrier Lifetime And Carrier Mobility Of Gaasn With Changing Nitrogen Concentration, Sun Gyu Park
Macalester Journal of Physics and Astronomy
In this work, we conducted Ultrafast Conductivity Measurements, using THz Spectroscopy to characterize the carrier mobility and the carrier lifetime of gallium arsenide nitride (GaAsN) thin films with a range of Nitrogen concentrations. The photoexcitation of semiconductor samples excites free charges by promoting electrons from the valence band to the conduction band. We then measure the change in conductivity by measuring the transmission of a THz electromagnetic pulse after photoexcitation and comparing with the signal that was measured without photoexcitation. The values of transmission are then converted into conductivity, from which we derive the carrier concentration and scattering time of ...
Automatic Leptonic Tensor Generation For Beyond The Standard Model (Bsm) Theories,
2021
Macalester College
Automatic Leptonic Tensor Generation For Beyond The Standard Model (Bsm) Theories, Diego F. Lopez Gutierrez
Macalester Journal of Physics and Astronomy
With the development of the Deep Underground Neutrino Experiment (DUNE) and Tokai-to-Hyper-Kamiokande (T2HK), we are entering the era of high-precision neutrino measurements. The colossal output of data from DUNE, plus the current data from several other neutrino experiments, will require a fast and efficient method of testing our BSM models in event generators. However, current methods for implementing a BSM theory in the event generators are prone to errors and time-consuming. We propose a novel program capable of automatically calculating the leptonic tensor for a given quantum field theory Lagrangian. This program is written in Python and utilizes the Universal ...
Model Of Electromagnetic Waves In An Axion-Induced Parity Symmetry Violation,
2021
Macalester College
Model Of Electromagnetic Waves In An Axion-Induced Parity Symmetry Violation, Sarah Lipstone
Macalester Journal of Physics and Astronomy
Axion particles have been postulated to resolve the strong CP problem in Quantum chromodynamics. The axion field may double as the inflaton field that produces cosmic inflation. In this project, we use a combination of analytical and numerical analysis to study how axion-induced parity symmetry violation affects the dynamics of electromagnetic waves.
Renewing The Paradigm: Simulating The Miso Region Electrical Grid Using Renewable Energy Generation With Implementation Of Long-Term Hydrogen Storage,
2021
Macalester College
Renewing The Paradigm: Simulating The Miso Region Electrical Grid Using Renewable Energy Generation With Implementation Of Long-Term Hydrogen Storage, Jackson C. Henningfield
Macalester Journal of Physics and Astronomy
The current electrical grid regime is not optimized to include renewable sources of power generation such as wind and solar. Electrical storage, as of now, is primarily established through the short-term generation and demand-meeting consumption leaving much of the grid susceptible to inefficiencies and power loss during natural events that leave grids out of commission. Delineating a new type of long-term storage, a hydrogen fuel cell, would ensure a reliable source of power to the masses regardless of the physical and climatic geography. The MISO region provides a perfect case study to introduce the ideas of diverse energy generation and ...
Electrical Grid Energy Storage Using Hydrogen: A Feasibility Study,
2021
Macalester College
Electrical Grid Energy Storage Using Hydrogen: A Feasibility Study, Elizabeth M. Curtiss
Macalester Journal of Physics and Astronomy
In this project, we studied the possibility of implementing hydrogen as energy storage. With the focus being on decarbonizing the grid, we looked at studies that were powered by renewable sources. In addition to utilizing renewable sources, we decided to study electrolysis as a way to produce hydrogen. Electrolysis is the splitting of water to obtain hydrogen and oxygen, which is a carbon free technique. Pulling from two different papers, we were able to construct an equation that modeled the levelized cost of producing hydrogen. We also calculated the levelized cost of a fuel cell too, with hydrogen as fuel ...
Particle Dynamics From The Method Of Nonlinear Realizations And Maxwell Group,
2021
Macalester College
Particle Dynamics From The Method Of Nonlinear Realizations And Maxwell Group, Daniel S. Clark
Macalester Journal of Physics and Astronomy
Professor Tonnis ter Veldhuis provides Macalester students with research opportunities in theoretical physics. In the Summer of 2020, a team of three students were introduced to the method of nonlinear realization of symmetries by studying Prof. Veldhuis’s prior research regarding an application of the method to membrane dynamics (1). Subsequent developments of this prior work involved research into torsion and riemann curvature tensors, as well as metric compatibility, highlighting the connection between symmetry and space-time structure. The foundation of this work was the D=4 Poincare algebra in the D=3 Lorentz group covariant form. After this introduction, each ...
Virtual Prototyping Of Liquid Lithium Divertor Concepts,
2021
Macalester College
Virtual Prototyping Of Liquid Lithium Divertor Concepts, Brennan Arnold
Macalester Journal of Physics and Astronomy
A tokamak divertor must withstand power deposition in excess of 10 MW/m^2 in steady state and much higher in disruptions, enough to destroy nearly any material. In order to handle this extreme heat, there is some interest in using liquid metal flows to continually renew the divertor surface. In this paper, we examine an idea for a divertor with a porous surface that allows liquid lithium flowing through the divertor to percolate to the plasma facing surface. This idea is complicated by magnetohydrodynamic drag, where the stong magnetic fields in the tokamak cause the lithium to flow too ...
Modeling Gyrating Motion Using Mathematica,
2021
Macalester College
Modeling Gyrating Motion Using Mathematica, Jonathan Alvarado-Gomez
Macalester Journal of Physics and Astronomy
In this report I will describe a method of creating animations of gyrating objects in Mathematica [4]. There are 4 inputs to a function called trajectory, which are a time step, maximum time duration, initial force vector, and a 3x3 matrix that represents a tensor for the gyration of the object. I utilized the computer program Mathematica [4] to create 3D images of a gyrating object in the object frame of view. A collection of these images were put together in order to make an animation, which can be used as a tool for future researchers to investigate interesting paths ...
Spirals And Skyrmions In Antiferromagnetic Triangular Lattices,
2021
University of Nebraska - Lincoln
Spirals And Skyrmions In Antiferromagnetic Triangular Lattices, Wuzhang Fang, Aldo Raeliarijaona, Po-Hao Chang, Alexey Kovalev, Kirill Belashchenko
Faculty Publications, Department of Physics and Astronomy
We study realizations of spirals and skyrmions in two-dimensional antiferromagnets with a triangular lattice on an inversion-symmetry-breaking substrate. As a possible material realization, we investigate the adsorption of transition-metal atoms (Cr, Mn, Fe, or Co) on a monolayer of MoS2, WS2, or WSe2 and obtain the exchange, anisotropy, and Dzyaloshinskii-Moriya interaction parameters using first-principles calculations. Using energy minimization and parallel-tempering Monte Carlo simulations, we determine the magnetic phase diagrams for a wide range of interaction parameters. We find that skyrmion lattices can appear even with weak Dzyaloshinskii-Moriya interactions, but their stability is hindered by magnetic anisotropy. However, a weak easy ...
Inspection Of Electronics Components For Cryogenic Temperature Operation,
2021
Iowa State University
Inspection Of Electronics Components For Cryogenic Temperature Operation, Navaneeth Poonthottathil, Frank Krennrich, Amanda Weinstein, Jonathan Eisch, Leonard J. Bond, Dan Barnard, Zhan Zhang, Lucas Koester
Aerospace Engineering Publications
Electronics operating at cryogenic temperatures play a critical role in future science experiments and space exploration programs. The Deep Underground Neutrino Experiment (DUNE) uses a cold electronics system for data taking. Specifically, it utilizes custom-designed Application Specific Integrated Circuits (ASICs). The main challenge is that these circuits will be immersed in liquid Argon and that they need to function for 20+ years without any access. Ensuring quality is critical, and issues may arise due to thermal stress, packaging, and manufacturing-related defects: if undetected, these could lead to long-term reliability and performance problems. This paper reports an investigation into non-destructive evaluation ...
Zeta Function Regularization And Its Relationship To Number Theory,
2021
East Tennessee State University
Zeta Function Regularization And Its Relationship To Number Theory, Stephen Wang
Electronic Theses and Dissertations
While the "path integral" formulation of quantum mechanics is both highly intuitive and far reaching, the path integrals themselves often fail to converge in the usual sense. Richard Feynman developed regularization as a solution, such that regularized path integrals could be calculated and analyzed within a strictly physics context. Over the past 50 years, mathematicians and physicists have retroactively introduced schemes for achieving mathematical rigor in the study and application of regularized path integrals. One such scheme was introduced in 2007 by the mathematicians Klaus Kirsten and Paul Loya. In this thesis, we reproduce the Kirsten and Loya approach to ...
