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Articles 28861 - 28890 of 294411

Full-Text Articles in Physical Sciences and Mathematics

A Search For Pulsars And An Exploration Of Dispersion Measure Within The Milky Way Galaxy, Emily Ware May 2024

A Search For Pulsars And An Exploration Of Dispersion Measure Within The Milky Way Galaxy, Emily Ware

Physics Undergraduate Honors Theses

A pulsar is a rapidly rotating neutron star which emits electromagnetic radiation from its magnetic poles. Upon detection from Earth, these signals have been dispersed in phase due to electron interactions in transit. The extent of this dispersion indicates information about both the distance to and the location of the pulsar, with respect to Earth and the Galactic plane. This project makes use of radio data from the 100m Robert C. Byrd Green Bank Telescope (GBT), presented in the form of prepfold plots assembled by the Pulsar Science Collaboratory (PSC). 1,007 of these plots were analyzed in order to determine …


The Analysis Of Mechanical Exfoliation Of Graphene For Various Fabrication And Automation Techniques, Lance Yarbrough May 2024

The Analysis Of Mechanical Exfoliation Of Graphene For Various Fabrication And Automation Techniques, Lance Yarbrough

Physics Undergraduate Honors Theses

Mechanical Exfoliation


Factors Influencing Performance Of Students In Software Automated Test Tools Course, Susmita Haldar, Mary Pierce, Luiz Fernando Capretz May 2024

Factors Influencing Performance Of Students In Software Automated Test Tools Course, Susmita Haldar, Mary Pierce, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

Formal software testing education is important for building efficient QA professionals. Various aspects of quality assurance approaches are usually covered in courses for training software testing students. Automated Test Tools is one of the core courses in the software testing post-graduate curriculum due to the high demand for automated testers in the workforce. It is important to understand which factors are affecting student performance in the automated testing course to be able to assist the students early on based on their needs. Various metrics that are considered for predicting student performance in this testing course are student engagement, grades on …


Green At Eye Level: From Measurement Approaches To Simulated Models And Inequality Assessments In U.S. Major Cities, Jingjing Yan May 2024

Green At Eye Level: From Measurement Approaches To Simulated Models And Inequality Assessments In U.S. Major Cities, Jingjing Yan

Graduate Theses and Dissertations

This dissertation delves into the multifaceted dynamics of urban greenness, addressing critical aspects of sustainable urban development. Providing urban green spaces has been widely acknowledged to offer numerous benefits to individuals and communities. Recently, there has been a growing recognition of the importance of evaluating urban greenness from a human-centered perspective, partly due to the rapid development of eye-level greenness measurement. First, to provide a comprehensive overview of measurement approaches and topics related to eye-level urban greenness, a systematic review of 77 papers was conducted in this research. This review revealed that street view images are the primarily utilized data …


An Educational Resource For Particle Identification (Pid) In Experimental Particle Physics Data, Richard Dube May 2024

An Educational Resource For Particle Identification (Pid) In Experimental Particle Physics Data, Richard Dube

University Scholar Projects

Although particle physics research is typically reserved for advanced undergraduates, algebra-based physics students can readily develop the foundational skills necessary to conduct particle physics research. Despite this, there is a shortage of educational resources that introduce particle physics to algebra-based physics students. This project, Particle Identification Playground, is a collection of Python-based activities that teach students about several fundamental topics in experimental particle physics research. Through these activities, students will learn about the common detectors used in particle physics, how they work, and how we can use these detectors to identify particles. Students are able to interact with 3D models …


Murmurations And Root Numbers, Alexey Pozdnyakov May 2024

Murmurations And Root Numbers, Alexey Pozdnyakov

University Scholar Projects

We report on a machine learning investigation of large datasets of elliptic curves and L-functions. This leads to the discovery of murmurations, an unexpected correlation between the root numbers and Dirichlet coefficients of L-functions. We provide a formal definition of murmurations, describe the connection with 1-level density, and provide three examples for which the murmuration phenomenon has been rigorously proven. Using our understanding of murmurations, we then build new machine learning models in search of a polynomial time algorithm for predicting root numbers. Based on our models and several heuristic arguments, we conclude that it is unlikely for …


How Can We Explain Empirical Formulas For Shrinkage Cracking Of Cement-Stabilized Pavement Layers, Edgar Daniel Rodriguez Velasquez, Vladik Kreinovich May 2024

How Can We Explain Empirical Formulas For Shrinkage Cracking Of Cement-Stabilized Pavement Layers, Edgar Daniel Rodriguez Velasquez, Vladik Kreinovich

Departmental Technical Reports (CS)

In pavement construction, one of the frequent defects is shrinkage cracking of the cement-stabilized pavement layer. To minimize this defect, it is important to be able to predict how this cracking depends on the quantities describing the pavement layer and the corresponding environment. Cracking is usually described by two parameters: the average width of the crack and the crack spacing. Empirical analysis shows that the dependence of the width on all related quantities is described by a power law. Power laws are ubiquitous in physics, they describe a frequent case when the dependence is scale-invariant -- i.e., does not change …


Understanding Perspectives Of Power In A College Mathematics Classroom, Laura Seeberger May 2024

Understanding Perspectives Of Power In A College Mathematics Classroom, Laura Seeberger

Honors College Theses

Power is embedded in teacher and student actions within mathematics classrooms, whether that power is known or not. Incorporating equity and inclusiveness requires a deeper understanding of this power behind actions. In this study, we developed and administered a three part survey questioning college faculty and college students how they perceive power related to common actions within a college mathematics classroom. For example, participants were asked whether a college math teacher assigning homework increased, decreased, or did both to the teacher’s power; then whether this action increased, decreased, or did both to a student’s power. Analysis of 16 faculty and …


Lhs 475 B: A Potential Venus Analog Orbiting A Nearby M Dwarf, K. Ment, D. Charbonneau, J. Irwin, J. G. Winters, E. Pass, A. Shporer, K. A. Collins, K. I. Collins, Eric L.N. Jensen, R. P. Schwarz, K. Horne, Z. Essack, V. B. Kostov, M. Kunimoto, A. Levine, S. Seager, R. Vanderspek, J. N. Winn May 2024

Lhs 475 B: A Potential Venus Analog Orbiting A Nearby M Dwarf, K. Ment, D. Charbonneau, J. Irwin, J. G. Winters, E. Pass, A. Shporer, K. A. Collins, K. I. Collins, Eric L.N. Jensen, R. P. Schwarz, K. Horne, Z. Essack, V. B. Kostov, M. Kunimoto, A. Levine, S. Seager, R. Vanderspek, J. N. Winn

Physics & Astronomy Faculty Works

Based on photometric observations by TESS, we present the discovery of a potential Venus analog transiting LHS 475, an M3 dwarf located 12.5 pc from the Sun. The mass of the star is 0.274 ± 0.015 M☉. The planet, originally reported as TOI 910.01, has an orbital period of 2.0291010 ± 0.0000017 days and an estimated radius of 0.975 ± 0.058 R⊕. We confirm the validity and source of the transit signal with MEarth and Las Cumbres Observatory Global Telescope ground-based follow-up photometry. We present radial velocity data from CHIRON that rule out massive companions. In …


Traffic Sign Extraction From Mobile Lidar Point Cloud, Yushin Ahn, Riadh Munjy, Ziyuan Li May 2024

Traffic Sign Extraction From Mobile Lidar Point Cloud, Yushin Ahn, Riadh Munjy, Ziyuan Li

Mineta Transportation Institute

The extraction of traffic signs from Mobile Light Detection and Ranging (LiDAR) point cloud data has become a focal point in transportation research due to the increasing integration of LiDAR technologies. LiDAR, a remote sensing technology, captures detailed three-dimensional point cloud data, offering a comprehensive view of the surrounding environment. Mobile LiDAR systems mounted on vehicles enable efficient data collection, particularly for large-scale road networks. This study aims to develop and refine techniques for extracting traffic signs from Mobile LiDAR point cloud data, essential for enhancing road safety, navigation systems, and intelligent transportation solutions. By leveraging LiDAR technology, new possibilities …


On Distortion Of Surface Groups In Right-Angled Artin Groups, Lucas Bridges May 2024

On Distortion Of Surface Groups In Right-Angled Artin Groups, Lucas Bridges

Mathematical Sciences Undergraduate Honors Theses

Surfaces have long been a topic of interest for scholars inside and outside of mathe- matics. In a topological sense, surfaces are spaces which appear flat on a local scale. Surfaces in this sense have a restricted set of properties, including the behavior of loops around a surface, codified in the fundamental group.

All but 3 surface groups have been shown to embed into a class of groups called right-angled Artin groups. The method through which these embeddings are created places large restrictions on all homomorphisms from surface groups to right-angled Artin groups.

One such restriction on these homomorphisms is …


A Comprehensive Investigation Of The Influence Of Geometric Structure On The Shape Memory Performance Of Nafion, Jade Thomas May 2024

A Comprehensive Investigation Of The Influence Of Geometric Structure On The Shape Memory Performance Of Nafion, Jade Thomas

Mechanical Engineering Undergraduate Honors Theses

While perfluorosulfonic acid (PFSA) membranes have primarily been used in fuel cells due to their chemical, thermal, and mechanical stability, one PFSA, Nafion, boasts two unique characteristics: a broad glass transition (~55 °C to 130 °C) and a temperature-persistent electrostatic network. The combination of these two characteristics endows Nafion with exceptional shape memory properties – the ability of a material to morph and transform into pre-programmed shapes when exposed to an external stimulus – with enhanced permanent shape memorization, and a potentially near-infinite number of temporary shape memorization. This study focused on expanding the base of knowledge surrounding Nafion’s shape …


Monero: Powering Anonymous Digital Currency Transactions, Jake Braddy May 2024

Monero: Powering Anonymous Digital Currency Transactions, Jake Braddy

Theses/Capstones/Creative Projects

Cryptocurrencies rely on a distributed public ledger (record of transactions) in order to perform their intended functions. However, the public’s ability to audit the network is both its greatest strength and greatest weakness: Anyone can see what address sent currency, and to whom the currency was sent. If cryptocurrency is ever going to take some of the responsibility of fiat currency, then there needs to be a certain level of confidentiality. Thus far, Monero has come out on top as the preferred currency for embodying the ideas of privacy and confidentiality. Through numerous cryptographic procedures, Monero is able to obfuscate …


The Search For Photonuclear Interactions Of Muons Utilizing Test Beam Data At The Large Hadron Collider, Miranda M. Williams May 2024

The Search For Photonuclear Interactions Of Muons Utilizing Test Beam Data At The Large Hadron Collider, Miranda M. Williams

2024 Spring Honors Capstone Projects - Archive

The ATLAS Detector is one of four different types of detectors within the Large Hadron Collider and is used to study the fundamental theories of the universe. Within the ATLAS experiment, beams of known composition and energies – otherwise known as “test beams” – are one of the many methods used to study specific physical phenomena. In this study, a test beam of muons with an energy of 160 GeV was analyzed to search for evidence of photonuclear interactions. This necessitated analyzing and filtering over 50,000 total events using specific parameters that would indicate such an event had occurred. To …


Navigate The World Of Rfid: Diversity, Capabilities, And Constraints Of Readers And Tags, Rachana Pandey May 2024

Navigate The World Of Rfid: Diversity, Capabilities, And Constraints Of Readers And Tags, Rachana Pandey

2024 Spring Honors Capstone Projects - Archive

Radio-Frequency Identification (RFID) technology, a method for storing and retrieving data through electromagnetic transmission to an RFID tag, is revolutionizing inventory and asset management in various sectors, including healthcare. This research explores the applications of RFID in a medical setting. It assesses various RFID readers and tags, focusing on their functional capabilities, ranges, and limitations within a medical environment. Employing a comprehensive approach, the study integrates an extensive literature review, comparative analysis, and empirical data from both experimental simulations and real-world healthcare scenarios. The aim is to identify RFID solutions that optimize surgical equipment management, thereby enhancing both operational efficiency …


Simulating Ice Particle Properties Under Varying Electric Fields, Joseph Thomas Cooney May 2024

Simulating Ice Particle Properties Under Varying Electric Fields, Joseph Thomas Cooney

Undergraduate Honors Capstone Projects

In this study, the interactions between atmospheric water molecules and an electrically charged dust particle were simulated in python to determine the role of electric charge and electric fields in atmospheric ice formation. Multiple levels of electric charge were tested, corresponding to different strengths of atmospheric electric fields. The TIP4P-2005 model for water was used to simulate these molecules under the influence of a central electric potential to represent the charged dust particle. These included a control group with no electric field (0 C), a group under a fair-weather strength of electric field (1.6*10-14 C), a foul-weather electric field (1.6*10-12 …


An Analysis Of Lyrical Repetition And Popularity In Popular Music Genres, Josh White May 2024

An Analysis Of Lyrical Repetition And Popularity In Popular Music Genres, Josh White

Undergraduate Honors Capstone Projects

This paper examines the correlation between repetitiveness and popularity in the genres of Christian, Country, EDM, Hip-Hop, Latin, Pop, R&B, and Rock. Repetitiveness is defined by the frequency of repeated words in lyrics, and the average number of streams per day defines popularity. This analysis also acknowledges the "popularity" metric provided by Spotify in calculating the correlation. To calculate this correlation, I wrote a program that accesses the Spotify and Genius APIs to gather metadata related to 76,069 songs from 1,246 artists, including data on repetitiveness, tempo, duration, and Spotify's audio metrics of "danceability," "energy," "speechiness," "acousticness," and "instrumentalness." I …


Evaluating Taxonomic Approaches: A Comparative Study Of Educational Frameworks Applied To Mathematics Assessments, Lily Roth May 2024

Evaluating Taxonomic Approaches: A Comparative Study Of Educational Frameworks Applied To Mathematics Assessments, Lily Roth

Undergraduate Honors Capstone Projects

The design of effective assessments and reporting of a student’s achievement on learning objectives are often overlooked, leaving educational stakeholders lacking the ability to create meaningful evaluations. To assist in creating substantial mathematics assessments this work seeks to answer the following research questions: ‘How can educational taxonomies be utilized to improve the design of mathematics assessments’? and ‘What are the strengths and weaknesses of applying different taxonomies onto mathematics assessments?’. The purpose of this study is to (1) develop a practical design instrument for easier identification and categorization of assessment questions within each educational taxonomy structure and (2) evaluate the …


Tasks For Learning Trigonometry, Sydnee Andreasen May 2024

Tasks For Learning Trigonometry, Sydnee Andreasen

All Graduate Reports and Creative Projects, Fall 2023 to Present

Many studies have been done using task-based learning within different mathematics courses. Within the field of trigonometry, task-based learning is lacking. The following research aimed to create engaging, mathematically rich tasks that meet the standards for the current trigonometry course at Utah State University and align with the State of Utah Core Standards for 7th through 12th grades. Four lessons were selected and developed based on the alignment of standards, the relevance to the remainder of the trigonometry course, and the relevance to courses beyond trigonometry. The four lessons that were chosen and developed were related to trigonometric ratios, graphing …


Utah Growing Water Smart: The Water-Land Use Integration Guidebook For Northern Utah, Kelly Kopp, Joanna Endter-Wada May 2024

Utah Growing Water Smart: The Water-Land Use Integration Guidebook For Northern Utah, Kelly Kopp, Joanna Endter-Wada

Utah Growing Water Smart

The Utah Growing Water Smart workshops bring together teams of key community staff and water and land use planning decision makers to help build a more resilient and sustainable water future. The workshops use a range of public engagement, planning, communication, and policy implementation tools to help community teams realize their water efficiency, smart growth, watershed health, and water resiliency goals.

This 4th edition of the Utah Growing Water Smart curriculum guidebook was prepared for the workshop focused on the Weber Basin Water Conservancy District service area and held on the campus of Utah State University in Logan, Utah …


Achieving Responsible Anomaly Detection, Xiao Han May 2024

Achieving Responsible Anomaly Detection, Xiao Han

All Graduate Theses and Dissertations, Fall 2023 to Present

In the digital transformation era, safeguarding online systems against anomalies – unusual patterns indicating potential threats or malfunctions – has become crucial. This dissertation embarks on enhancing the accuracy, explainability, and ethical integrity of anomaly detection systems. By integrating advanced machine learning techniques, it improves anomaly detection performance and incorporates fairness and explainability at its core.

The research tackles performance enhancement in anomaly detection by leveraging few-shot learning, demonstrating how systems can effectively identify anomalies with minimal training data. This approach overcomes data scarcity challenges. Reinforcement learning is employed to iteratively refine models, enhancing decision-making processes. Transfer learning enables the …


Disinfection Byproducts And Their Precursors In Drinking Water Sources: Origins, Influencing Factors, And Environmental Insights, Rong Xiao, Yang Deng, Zuxin Xu, Wenhai Chu May 2024

Disinfection Byproducts And Their Precursors In Drinking Water Sources: Origins, Influencing Factors, And Environmental Insights, Rong Xiao, Yang Deng, Zuxin Xu, Wenhai Chu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health. However, current analysis approaches are not ideal, as they tend to be laborious, time-consuming, or technically difficult. Disinfection byproducts (DBPs) are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment. Since DBP precursors have various origins (e.g., natural, domestic, industrial, and agricultural sources), and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive, we argue that DBPs and …


Proof-Of-Concept For Converging Beam Small Animal Irradiator, Benjamin Insley May 2024

Proof-Of-Concept For Converging Beam Small Animal Irradiator, Benjamin Insley

Dissertations and Theses (Open Access)

The Monte Carlo particle simulator TOPAS, the multiphysics solver COMSOL., and

several analytical radiation transport methods were employed to perform an in-depth proof-ofconcept

for a high dose rate, high precision converging beam small animal irradiation platform.

In the first aim of this work, a novel carbon nanotube-based compact X-ray tube optimized for

high output and high directionality was designed and characterized. In the second aim, an

optimization algorithm was developed to customize a collimator geometry for this unique Xray

source to simultaneously maximize the irradiator’s intensity and precision. Then, a full

converging beam irradiator apparatus was fit with a multitude …


The Olmsted Fault, Southernmost Illinois: A Key To Understanding Seismic Hazard In The Northern New Madrid Seismic Zone, Christopher E. Bexfield May 2024

The Olmsted Fault, Southernmost Illinois: A Key To Understanding Seismic Hazard In The Northern New Madrid Seismic Zone, Christopher E. Bexfield

Theses and Dissertations

The northernmost extent of the New Madrid seismic zone in the central USA has been investigated using an integrated approach involving both compressional-wave (P) and horizontally polarized-wave (SH) seismic reflection and regional and dedicated borehole geophysical information in order to assess seismic hazard and risk. Our study area, centered around southernmost Illinois and western Kentucky, USA, represents an area of concentrated facilities (e.g., lock and dam sites and chemical plants on the Ohio River near its confluence with the Mississippi River) as well as an area of high potential soil amplification due to earthquake shaking. Integrated high-resolution seismic reflection profiles …


Geometric Principles In Architecture Aesthetics, Vincent Gemmiti May 2024

Geometric Principles In Architecture Aesthetics, Vincent Gemmiti

Architecture Undergraduate Honors Theses

This study focuses on geometric formalism in three major monuments across different architectural eras in time. The use of three distinct geometric principles to outline the use of pure or manufactured shapes and figures helps to discover and isolate an aesthetic component of architecture within which it is contained. A collection of studies are implemented and are focused on orthographic drawings from each monument in horizontality and verticality, consisting of a dual set of overlay and interpretative drawings for each type of orthographic representation for each monument. A discussion follows and highlights the changes or similarities over time the role …


Free And Forced Vibrations Of Elastically Restrained Cantilever With Lumped Oscillator, Alireza Babaei, Johné Parker, Paria Moshaver May 2024

Free And Forced Vibrations Of Elastically Restrained Cantilever With Lumped Oscillator, Alireza Babaei, Johné Parker, Paria Moshaver

Earth and Environmental Sciences Faculty Publications

The efficiency assessment of cantilever-based energy harvesters relies on vibrational analysis, which necessitates modi- fications aimed at enhancing efficiency. These modifications involve manipulating the fundamental frequency to lower values and encompassing a wider range of resonances within a specified bandwidth. Consequently, this paper introduces an original analytical-numerical exploration into the vibratory response of a cantilever with a novel boundary condi- tion involving an elastically restrained oscillator-spring arrangement. At the microbeam’s tip, an oscillator is elastically confined by a linear spring, resulting in a novel set of coupled governing equations and a distinct shearing boundary condition. Microbeam equations is derived from …


Evaluating The Epidemiological, Hormonal, And Psychosocial Sex-Based Differences In Sports-Related Concussion Outcomes, Samantha Kanny May 2024

Evaluating The Epidemiological, Hormonal, And Psychosocial Sex-Based Differences In Sports-Related Concussion Outcomes, Samantha Kanny

All Dissertations

Sports-related concussions (SRCs) affect approximately 3.8 million athletes in the United States per year. A multitude of risk factors including age, sex, concussion history and prior medical conditions have been observed to significantly increase sports-related concussion symptom burden. Researchers have posited many reasons to explain sex-based differences in SRC outcomes, often categorized by biological characteristics or sociocultural factors, however, females are vastly underrepresented in sports-related concussion research, making it difficult to understand the true mechanisms underlying SRC sex-based differences. The goal of this dissertation is to help fill the current gap in knowledge on sex-based differences in sports-related concussion outcomes. …


Impact Of Property Covariance On Cluster Weak Lensing Scaling Relations, Zhuowen Zhang, Arya Farahi, Daisuke Nagai, Erwin T. Lau, Joshua Frieman, Marina Ricci, Anja Von Der Linden, Hao-Yi Wu, Lsst Dark Energy Science Collaboration May 2024

Impact Of Property Covariance On Cluster Weak Lensing Scaling Relations, Zhuowen Zhang, Arya Farahi, Daisuke Nagai, Erwin T. Lau, Joshua Frieman, Marina Ricci, Anja Von Der Linden, Hao-Yi Wu, Lsst Dark Energy Science Collaboration

Physics Faculty Publications and Presentations

We present an investigation into a hitherto unexplored systematic that affects the accuracy of galaxy cluster mass estimates with weak gravitational lensing. Specifically, we study the covariance between the weak lensing signal, ΔΣ, and the ‘true’ cluster galaxy number count, Ngal, as measured within a spherical volume that is void of projection effects. By quantifying the impact of this covariance on mass calibration, this work reveals a significant source of systematic uncertainty. Using the MDPL2 simulation with galaxies traced by the SAGE semi-analytic model, we measure the intrinsic property covariance between these observables within the three-dimensional vicinity of …


The Jwst Early Release Science Program For Direct Observations Of Exoplanetary Systems. V. Do Self-Consistent Atmospheric Models Represent Jwst Spectra? A Showcase With Vhs 1256-1257 B, Simon Petrus, Niall Whiteford, Polychronis Patapis, Beth A. Biller, Andrew Skemer, Sasha Hinkley, Genaro Suárez, Paulina Palma-Bifani, Caroline V. Morley, Pascal Tremblin, Benjamin Charnay, Johanna M. Vos, Jason J. Wang, Jordan M. Stone, Mickaël Bonnefoy, Gaël Chauvin, Brittany E. Miles, Aarynn L. Carter, Anna Lueber, Christiane Helling, Ben J. Sutlieff, Markus Janson, Eileen C. Gonzales, Kielan K.W. Hoch, Olivier Absil, William O. Balmer, Anthony Boccaletti, Mariangela Bonavita, Mark Booth, Brendan P. Bowler, Et Al, Kimberly Ward-Duong May 2024

The Jwst Early Release Science Program For Direct Observations Of Exoplanetary Systems. V. Do Self-Consistent Atmospheric Models Represent Jwst Spectra? A Showcase With Vhs 1256-1257 B, Simon Petrus, Niall Whiteford, Polychronis Patapis, Beth A. Biller, Andrew Skemer, Sasha Hinkley, Genaro Suárez, Paulina Palma-Bifani, Caroline V. Morley, Pascal Tremblin, Benjamin Charnay, Johanna M. Vos, Jason J. Wang, Jordan M. Stone, Mickaël Bonnefoy, Gaël Chauvin, Brittany E. Miles, Aarynn L. Carter, Anna Lueber, Christiane Helling, Ben J. Sutlieff, Markus Janson, Eileen C. Gonzales, Kielan K.W. Hoch, Olivier Absil, William O. Balmer, Anthony Boccaletti, Mariangela Bonavita, Mark Booth, Brendan P. Bowler, Et Al, Kimberly Ward-Duong

Astronomy: Faculty Publications

The unprecedented medium-resolution (R λ ∼ 1500-3500) near- and mid-infrared (1-18 μm) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12-20 M Jup) L-T transition (L7) companion VHS 1256 b gives access to a catalog of molecular absorptions. In this study, we present a comprehensive analysis of this data set utilizing a forward-modeling approach applying our Bayesian framework, ForMoSA. We explore five distinct atmospheric models to assess their performance in estimating key atmospheric parameters: T eff, log(g), [M/H], C/O, γ, f sed, and R. Our findings reveal that each parameter’s estimate is significantly influenced by factors …


Volcanic Glass As A Proxy For Paleotopography Suggests New Features In Late-Miocene Oregon, Julian Cohen, John Bershaw, Richard Hugo May 2024

Volcanic Glass As A Proxy For Paleotopography Suggests New Features In Late-Miocene Oregon, Julian Cohen, John Bershaw, Richard Hugo

Geology Faculty Publications and Presentations

Volcanic glass has been used extensively as a paleoaltimeter. Deuterium (2H) concentrations in glass have been found to be stable over geologic timescales, making δ2H (also known as δD) a reliable proxy for ancient water chemistry. However, continued work revolves around better understanding how different factors affect preserved water in volcanic ash. Here, we analyze δD in the Rattlesnake Tuff (RST), a widespread ca. 7 Ma ash-flow tuff, and create a paleoisoscape to assess variations in δD across Oregon during that time. To this end, 16 ash samples were collected across central and eastern Oregon from …