Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

31,389 Full-Text Articles 47,142 Authors 5,714,572 Downloads 266 Institutions

All Articles in Physics

Faceted Search

31,389 full-text articles. Page 8 of 862.

Calculating Centrality Variables And Geometric Quantities Associated With High Energy Pb+Pb And Au+Au Collisions Using A Monte Carlo Glauber Model, Anya Wolterman 2020 Macalester College

Calculating Centrality Variables And Geometric Quantities Associated With High Energy Pb+Pb And Au+Au Collisions Using A Monte Carlo Glauber Model, Anya Wolterman

Macalester Journal of Physics and Astronomy

The Glauber model provides insight into the initial state of nuclear collisions by treating them in terms of the interactions between their constituent nucleons, in accordance with theories about the scattering of composite particles. These phenomenological techniques are commonly used to determine various geometric quantities associated with such complex, femtoscopic many-body systems. The Monte Carlo Glauber approach uses a random impact parameter and measured nuclear densities to investigate quantifiable properties like particle multiplicity and average geometric eccentricity for heavy ion collisions. The former involves incorporating a particle production model to plot the total transverse energy or the number of particles ...


Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman 2020 Macalester College

Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman

Macalester Journal of Physics and Astronomy

Glancing angle deposition (GLAD) is a process in which thin films are deposited onto a substrate with obliquely incident vapor together with precisely controlled azimuthal substrate rotation. Ballistic shadowing effects due to the oblique incidence produce nanoscale structures, and a variety of feature shapes, including tilted columns, helices, and vertical columns can be achieved by varying the azimuthal rotation during the deposition process. Due to this control of morphology and the compatibility of the process with a wide variety of materials, GLAD films have found applications in a variety of fields including sensing, photonics, photovoltaics, and catalysis, where they are ...


The Leoncino Dwarf: A Neutral Hydrogen Analysis Of Agc 198691 And Its Extremely Metal-Poor Environment, Tylyn Page 2020 Macalester College

The Leoncino Dwarf: A Neutral Hydrogen Analysis Of Agc 198691 And Its Extremely Metal-Poor Environment, Tylyn Page

Macalester Journal of Physics and Astronomy

Studies of low-mass galaxies are important for populating the low-mass ends of funda- mental physical relations. Extremely metal-poor (XMP) galaxies are low-mass galaxies with gas-phase oxygen abundances of 12+log(O/H) ≤ 7.35 ( 1/20 Z⊙), and are especially interesting as proxies for studying the distant past, as their chemical makeup resembles those of galaxies in the early universe. AGC 198691, referred to as the Leoncino Dwarf, was discovered through the Arecibo Legacy Fast ALFA (ALFALFA) survey and found to have an oxygen abundance of less than 3% Z⊙. Presented here are the results of recent Karl G. Jansky ...


Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore 2020 Macalester College

Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore

Macalester Journal of Physics and Astronomy

The current energy grid in the United States is dominated by carbon intense energy generation methods that are based on production when and where it is required. However, solar and wind power have proved themselves as the most promising carbon free energy generation sources. Due to the unpredictable and uncontrollable nature of energy production from solar and wind, large scale integration of these resources into the electric grid will require robust storage capacity. In this project, we model the energy grid of the Midcontinent Independent System Operator (MISO) energy region with high concentrations of solar and wind power to analyze ...


Deposition Of Tin For Battery And Supercapacitor Electrodes For Energy Storage, Kieran M. Liming 2020 Macalester College

Deposition Of Tin For Battery And Supercapacitor Electrodes For Energy Storage, Kieran M. Liming

Macalester Journal of Physics and Astronomy

Titanium Nitride (TiN) can be sputtered into a thin film, and is a promising component for battery and supercapacitor electrodes. This research explored the relationship between Nitride partial pressure and film characteristics. We sputtered TiN into thin films in a low vacuum environment at tempuratures of approximately 70o C. Most films were deposited over the course of one hour including a five minute presputtering period where the substrate was covered. We found that film thickness, system voltage, and film restivitiy to be a function of N2 partial pressure.


Searching For Doublet Vectorlike Leptons Using The Atlas Particle Detector, Brynn Keller 2020 Macalester College

Searching For Doublet Vectorlike Leptons Using The Atlas Particle Detector, Brynn Keller

Macalester Journal of Physics and Astronomy

Vectorlike leptons are a simple extension of the standard model, akin to a fourth family of leptons. This paper describes aspects of the preparation for a search for VLLs at an ATLAS particle collider. During this research, signal and control regions were determined with use of a Monte Carlo simulation in order to best estimate where to measure different kinds of background and where to search for a potential signal. These signal and control regions were optimized with respect to MET, LT, and number of light and heavy leptons with a goal of a 95\% confidence limit.


A Search For Pulsars Towards The Galactic Center, Jacob W. Hetrick, Kunal Mooley, Preshanth Jagannathan 2020 Macalester College

A Search For Pulsars Towards The Galactic Center, Jacob W. Hetrick, Kunal Mooley, Preshanth Jagannathan

Macalester Journal of Physics and Astronomy

We present observations from two separate methods for observing the Galactic Center in an attempt to characterize its pulsar and neutron star populations. A persistent puzzle of the past 20 years has been the lack of pulsar detections towards the Galactic Center, specifically within a few parsecs of the central supermassive black hole Sgr A*. This object is bright in the total intensity of its polarized emission, but is very weakly linearly polarized. We take advantage of these circumstances in an experimental search technique where we utilize the Faraday effect in an attempt to detect high rotation measure (RM) point ...


Modeling Scavenging For A Hydraulic Free-Piston Engine, Nathan Davies 2020 Macalester College

Modeling Scavenging For A Hydraulic Free-Piston Engine, Nathan Davies

Macalester Journal of Physics and Astronomy

The hydraulic free-piston engine at the University of Minnesota offers a solution to improve the hydraulic efficiency and reduce emission output of off-road vehicles. We developed a MATLAB Simulink model to track the pressure, temperature, and mass profile of the fuel within the cylinder during operation. By varying different initial conditions of our model, we found that a higher intake manifold pressure and larger bottom dead center location results in higher scavenging efficiency. These results can be used to improve the controller of this engine and better maintain stable operation.


Alfalfa Harvest: Hi Imaging And 3d Modeling Of Candidate Local Group Dwarf Galaxies, Lilly Bralts-Kelly, Susie Paine, Elizabeth A. K. Adams, John M. Cannon 2020 Macalester College

Alfalfa Harvest: Hi Imaging And 3d Modeling Of Candidate Local Group Dwarf Galaxies, Lilly Bralts-Kelly, Susie Paine, Elizabeth A. K. Adams, John M. Cannon

Macalester Journal of Physics and Astronomy

Isolated neutral hydrogen (HI) clouds, or "ultra-compact high-velocity clouds" (UCHVCs), form a small subset of detections by the Arecibo Legacy Fast ALFA (ALFALFA) blind extragalactic survey. These systems, if located within ~1 Mpc, would populate the lowest-mass end of the HI mass function. Subsequent optical imaging has revealed that some of these UCHVCs harbor associated (thought sparse) stellar populations, suggesting that they may be some of the most extreme galaxies known in the Local Volume, with properties akin to ultra-faint dwarf galaxies but with significant neutral gas reservoirs. In this work, we investigate the neutral hydrogen properties of six UCHVC ...


Leoncino And Ugc 5186, Josh Bartz 2020 Macalester College

Leoncino And Ugc 5186, Josh Bartz

Macalester Journal of Physics and Astronomy

AGC 198691 is commonly known as the Leoncino Dwarf and is one of the most metal poor galax- ies known. An Arecibo observation in 2011 first suggested that Leoncino could be gravitationally interacting with its neighbor UGC 5186. In this paper new VLA data is used to examine the H I com- ponent of both galaxies to determine their gravitational relationship. Although the VLA could not confirm intragalactic gas seen by Aricebo, the H I density and velocity components are strong indirect evidence of gravitational interaction. UGC 5186 has a large gaseous arm reaching in the direction of Leoncino. Additionally ...


Coherent Captain Mills: The Search For Sterile Neutrinos, Ashley Elliott, Jeramy Gordon, Jonah Greenwood, Rachel Lake, Ryder Moreno, Emily Strawn, Kate Walker 2020 Embry-Riddle Aeronautical University

Coherent Captain Mills: The Search For Sterile Neutrinos, Ashley Elliott, Jeramy Gordon, Jonah Greenwood, Rachel Lake, Ryder Moreno, Emily Strawn, Kate Walker

Discovery Day - Prescott

The observation of neutrino oscillations confirms that the active neutrinos (νe, νμ, ντ) are comprised of three mass eigenstates with Δm2 values between 10-3 to 10-5 eV2 . However, a persistent phenomenon has been observed at LSND, MiniBooNE and other shortbaseline experiments (SBE) where Δm2 ~ 1eV2 and is not compatible with the current mixing between mass eigenstates. However, a 4th neutrino, a sterile neutrino (νs) that doesn’t participate in weak interactions could explain the phenomena observed as SBE’s. An experiment has been constructed at TA-53 at Los Alamos National Laboratory to investigate this large Δm2 ~ 1eV2 and determine conclusively ...


The Effect Of Chirality On Dna Threading: Exploring Binuclear Ruthenium Lntercalators Using Optical Tweezers, Adam A. Jabak 2020 Bridgewater State University

The Effect Of Chirality On Dna Threading: Exploring Binuclear Ruthenium Lntercalators Using Optical Tweezers, Adam A. Jabak

Honors Program Theses and Projects

Using optical tweezers, we have been able to study the interactions of small molecules and prospective cancer drugs with DNA. One type of these molecules, known as threading intercalators, has a flat planar intercalating moiety in between the molecule’s bulky ancillary supporting ligands. In order to bind with DNA, they have to thread their bulky ancillary ligands in between the DNA base pairs. Due to this requirement for binding, these molecules tend to have high binding affinities and slow kinetics. In this thesis, we explore the binding properties of a ruthenium-based threading intercalator -[μ-bidppz(phen)4Ru2]4+, or -P ...


Examining The Effect Of El Nino Phenomena And Pacific Sea Surface Temperature On The Climate Of The Glacierized White Mountains In Peru, Emily Reardon 2020 Bridgewater State University

Examining The Effect Of El Nino Phenomena And Pacific Sea Surface Temperature On The Climate Of The Glacierized White Mountains In Peru, Emily Reardon

Honors Program Theses and Projects

The purpose of this study is to determine if there is a correlation between the El Ni~no Southern Oscillation, sea surface temperatures (SST) and the climate of the Rio Santa Basin. This study is an important step in understanding the dynamics of the glaciers as a critical control on hydrological features in alpine Andes Valleys. Temperature and precipitation measurements pulled from ground based weather stations in the Rio Santa drainage basin were aggregated, synchronized, and correlated with the changes in the Pacific ocean SST o the coast of Peru and into the central Pacific. The expectation is that we ...


Spectral Observations Of The 2019 South American Total Solar Eclipse, Sarah Auriemma 2020 Bridgewater State University

Spectral Observations Of The 2019 South American Total Solar Eclipse, Sarah Auriemma

Honors Program Theses and Projects

On July 2, 2019, a total solar eclipse was visible in parts of Chile and Ar-gentina. I joined the Solar Wind Sherpas, an international group of scientists,engineers, students, and eclipse enthusiasts, to South America to make obser-vations of the solar corona (the Sun’s upper atmosphere) during the eclipse.The Sherpas were split into three teams along the path of totality and my groupwas stationed at Mamalluca Observatory in Vicuna, Chile. One of the instru-ments we used at this side was a three-channel (red, green, and blue) spectrom-eter designed by A. Ding, of Hawai’i’s Institute for Astronomy ...


Demonstrating And Testing The Deutsch-Jozsa Quantum Algorithm Towards The Realization Of Quantum Computing At Bsu, John J. Gilmore Jr. 2020 Bridgewater State University

Demonstrating And Testing The Deutsch-Jozsa Quantum Algorithm Towards The Realization Of Quantum Computing At Bsu, John J. Gilmore Jr.

Honors Program Theses and Projects

The world is changing, and fast. Quantum computing and photonic engineering are revolutionary new technologies that could change the way humans interact with information; though the eld hasn't always been that way. As with most new elds, proof of concept is needed to show that this new technology isn't just hear to stay, but it's hear to take the lead. In this, nothing is more important the the Deutsch-Jozsa Quantum algorithm; as it did just that . The majority of this research paper revolves around understanding the very essence of quantum computing. As the eld of quantum computing ...


Image Processing Of Narrow Band Solar Eclipse Data Using Python And Maxim Dl, Rydia Hayes-Huer 2020 Bridgewater State University

Image Processing Of Narrow Band Solar Eclipse Data Using Python And Maxim Dl, Rydia Hayes-Huer

Honors Program Theses and Projects

On July 2, 2019, a total solar eclipse (TSE) was observable from Chile and Argentina. In Chile, I worked alongside the Solar Wind Sherpas, an international group led by Dr. Shadia Habbal from the University of Hawai'i Institute for Astronomy, to make observations of the solar corona and gather information about its elemental composition. Narrow band data were collected for Fe XI, Fe XIV, and Ar X. Data collected during TSE observations can be used to help solve two puzzles in solar physics: the coronal heating problem and the mechanisms responsible for the fast and slow solar winds. Narrow ...


Determining The Kinetic Isotope Effect Of Ruthenium Compound Ru(Bpy)₂(Bpyno)(Pf₆)₂ Using Artificial Photosynthesis, Alexandra I. Kirkvold 2020 University of South Dakota

Determining The Kinetic Isotope Effect Of Ruthenium Compound Ru(Bpy)₂(Bpyno)(Pf₆)₂ Using Artificial Photosynthesis, Alexandra I. Kirkvold

Honors Thesis

The world’s demand for energy is ever-increasing, but its fuel resources are being depleted at an alarming rate. A potential solution for this crisis lies in using ruthenium-based compounds to produce hydrogen for use in fuel cells. This research uses the process of artificial photosynthesis to learn more about a promising ruthenium-based compound, Ru(bpy)₂(bpyNO)(PF₆)₂. The experiment tests the reaction for oxygen production in both H2O and D2O to determine the Kinetic Isotope Effect of the compound and, thus, aid future research working to understand the reaction mechanisms. The analysis shows ...


Investigatin Actin-Myosin Mechanics To Model Heart Disease Using Fluorescence Microscopy And Optical Trapping, Justin Edward Reynolds 2020 University of Mississippi

Investigatin Actin-Myosin Mechanics To Model Heart Disease Using Fluorescence Microscopy And Optical Trapping, Justin Edward Reynolds

Honors Theses

Hypertrophic cardiomyopathy (HCM) is a hereditary disease in which the myocardium becomes hypertrophied, making it more difficult for the heart to pump blood. HCM is commonly caused by a mutation in the β-cardiac myosin II heavy chain. Myosin is a motor protein that facilitates muscle contraction by converting chemical energy from ATP hydrolysis into mechanical work and concomitantly moving along actin filaments. Optical tweezers have been used previously to analyze single myosin biophysical properties; however, myosin does not work as a single unit within the heart. Multiple myosin interacts to displace actin filaments and do not have the same properties ...


Heel Down And Toe-Off Time Measured With Ultrasonic Doppler System And Force Plate Sensor, Sabin Timsina 2020 University of Mississippi

Heel Down And Toe-Off Time Measured With Ultrasonic Doppler System And Force Plate Sensor, Sabin Timsina

Honors Theses

Collie Box is a medical device that measures the gait parameters of the person walk- ing in front of it. This device uses the Ultrasonic Doppler system to extract the heel-contact and toe-off times of a person walking within the range of 2-10 meters. These times are used to determine the leg’s swing phase and double stance times. The ultrasonic transducer of 10mm diameter is driven at 40kHz. At the time of the heel-contact and toe-off, foot velocity is zero while the torso part of the human body is still in motion. The wide directivity of 10mm diameter ultrasonic ...


Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr. 2020 University of Mississippi

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized ...


Digital Commons powered by bepress