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2024

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Full-Text Articles in Physical Sciences and Mathematics

2024 May 9 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University May 2024

2024 May 9 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


Supercontinuum Generation With A Ti: Sapphire Laser And Photonic Crystal Fiber, Joseph Lange May 2024

Supercontinuum Generation With A Ti: Sapphire Laser And Photonic Crystal Fiber, Joseph Lange

Celebrating Scholarship and Creativity Day (2018-)

A broad spectrum of visible light was produced by focusing the 50-fs, 800-nm, 5-nJ pulses from an unamplified Ti:sapphire laser into a 20-cm-long photonic crystal fiber. A prism pair was used to compensate for material dispersion of the system. Different focusing methods were investigated including beam telescopes and lenses of various focal lengths. A 3X beam expander telescope near the laser output and a 3-cm focal length achromatic lens after the prism pair were found to work best for coupling the light into the fiber which has a core diameter of 1.7 μm.


Sunyaev-Zeldovich Effect In The Intra-Cluster Medium, Nathan Fronk May 2024

Sunyaev-Zeldovich Effect In The Intra-Cluster Medium, Nathan Fronk

Senior Seminars and Capstones

This paper covers the Sunyaev-Zeldovich effect, it’s derivation, and it’s applications in astronomy. The effect is a result of inverse Compton scattering in a cloud of hot charged particles, causing an increase in the temperature of the the cosmic microwave background radiation passing through the cloud. This change in temperature can be measured, and used to calculate the physical properties of the structure in question. This paper focuses on the a method used by Adam et al. (2017) to find a temperature map of the intra-cluster medium.


Relative Influence Of Sea State And Mean, Turbulent, And Heterogenous Refractivity On X-Band Propagation, Douglas M. Pastore, Erin E. Hackett May 2024

Relative Influence Of Sea State And Mean, Turbulent, And Heterogenous Refractivity On X-Band Propagation, Douglas M. Pastore, Erin E. Hackett

Marine Science

In predicting electromagnetic wave propagation within the marine atmospheric surface layer, it is common to assume steady homogenous conditions. However, discrepancies between predicted and measured propagation remain, which could be due in-part to turbulent fluctuations of the refractive index, spatially heterogenous evaporative ducting environments, and mischaracterization of the rough ocean bottom boundary. To better understand the relative importance of these contributors, this study explores the sensitivity of X-band propagation to parameters describing sea-state conditions and refractive environments, including turbulent fluctuations and spatially heterogenous conditions. This study employs the extended Fourier Amplitude Sensitivity Test to compute sensitivity indices that evaluate the …


Software Development And Market Research Process Of Plasma Software Distribution, Connor Moore May 2024

Software Development And Market Research Process Of Plasma Software Distribution, Connor Moore

Honors College Theses

When trying to find the right software for scientific research, one may have to comb through the internet to acquire a suitable tool. Much of the scientific software online is in mostly unknown web pages where the only way to find the software is to already know about it, be told about it, or find the software by pure chance. Even worse, with few verification systems in place they may try a new program only for it to turn out to be malware. The search for the right software takes time away from the scientists, slowing the overall pace of …


Synthesis And Analysis Of A Novel Magnetic Surfactant, Donovan Turpin May 2024

Synthesis And Analysis Of A Novel Magnetic Surfactant, Donovan Turpin

Honors Theses

Researchers in the University of Mississippi Chemical Engineering Department have suggested that chelation of a large magnetic transition metal, namely dysprosium, into the large polar head group of a surfactant could result in a magnetic surfactant. This project was aimed at synthesizing a surfactant with a large enough head group and negative charge (specifically EDTA) to support this ion and demonstrating that the chelation process was successful. If so, the molecule would ideally be capable of forming micelles which could extract oily substances from water using a strong magnet—possibly applicable to environmental crises like oil spills.

NMR analysis has suggested, …


A Comparison Of Assessment Experiences Between Standards-Based Practices And Traditional Practices Within Secondary Mathematics Classrooms, Emily Mayes May 2024

A Comparison Of Assessment Experiences Between Standards-Based Practices And Traditional Practices Within Secondary Mathematics Classrooms, Emily Mayes

Honors Theses

The purpose of this research was to compare assessment experiences and find ways to improve those experiences for students in two mathematics classrooms: one classroom that employs Standards-Based Grading and one classroom that uses traditional grading practices. The research examines students’ perceptions regarding their level of preparation, their anxiety levels surrounding assessment, the validity of assessments, and using assessments and grading practices to give accurate indications of student progress in their learning, given the students’ perceptions. Students in both settings voluntarily and anonymously participated in completing pre- and post-assessment free-response surveys which asked questions about students’ assessment experiences. This research …


Theoretical Spectroscopic Predictions Of Electronically Excited States, Noah R. Garrett May 2024

Theoretical Spectroscopic Predictions Of Electronically Excited States, Noah R. Garrett

Honors Theses

The quest for faster computation of anharmonic vibrational frequencies of both ground and excited electronic states has led to combining coupled cluster theory harmonic force constants with density functional theory (DFT) cubic and quartic force constants for defining a quartic force field (QFF) utilized in conjunction with vibrational perturbation theory at second order (VPT2). This work shows that explicitly correlated coupled cluster theory at the singles, doubles, and perturbative triples level [CCSD(T)-F12] provides accurate anharmonic vibrational frequencies and rotational constants when conjoined with any of B3LYP, CAM-B3LYP, BHandHLYP, PBE0, and ωB97XD for roughly one-quarter of the computational time of the …


Examining Galaxy Bulge Regions With The Sloan Digital Sky Survey, Sarah E. Draves, Ariyeh Maller May 2024

Examining Galaxy Bulge Regions With The Sloan Digital Sky Survey, Sarah E. Draves, Ariyeh Maller

Publications and Research

Nearly all of the ordinary matter in the universe is located in galaxies, which are made up stars, gas, dust, and black holes, and range in size from a few thousand to a few hundred thousand light years across. Galaxies come in different shapes, but many of them are spiral shaped, and some of those have a central bulge region that is distinct from the rest of the galactic disk. This project used a large data set of galaxies that had their bulge and disk components separated to see what correlations those fractions of each galaxy have with other galaxy …


The Use Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Properties Of Green Roof Media And Granular Soils, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr. May 2024

The Use Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Properties Of Green Roof Media And Granular Soils, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr.

Publications and Research

This study investigates using repurposed whole textiles to modify the mechanical and hydrogeological properties of lightweight Green Roof media and granular pavement soils.

Green Roof Media Green roofs aim to bring the advantages of suburban agriculture to urban environments while improving energy efficiency and enhancing stormwater management in public, commercial, and residential buildings. Previous studies by City Tech undergraduate research assistants demonstrated significant modification in hydrogeological properties when incorporating textile fabric up to 3% textile by weight (%Tex) at an aspect ratio of 1:1. The effects of mixing repurposed whole textile fiber with Green Roof media is evaluated with regards …


Machine Learning: Face Recognition, Mohammed E. Amin May 2024

Machine Learning: Face Recognition, Mohammed E. Amin

Publications and Research

This project explores the cutting-edge intersection of machine learning (ML) and face recognition (FR) technology, utilizing the OpenCV library to pioneer innovative applications in real-time security and user interface enhancement. By processing live video feeds, our system encodes visual inputs and employs advanced face recognition algorithms to accurately identify individuals from a database of photos. This integration of machine learning with OpenCV not only showcases the potential for bolstering security systems but also enriches user experiences across various technological platforms. Through a meticulous examination of unique facial features and the application of sophisticated ML algorithms and neural networks, our project …


A Nlp Approach To Automating The Generation Of Surveys For Market Research, Anav Chug May 2024

A Nlp Approach To Automating The Generation Of Surveys For Market Research, Anav Chug

Honors College Theses

Market Research is vital but includes activities that are often laborious and time consuming. Survey questionnaires are one possible output of the process and market researchers spend a lot of time manually developing questions for focus groups. The proposed research aims to develop a software prototype that utilizes Natural Language Processing (NLP) to automate the process of generating survey questions for market research. The software uses a pre-trained Open AI language model to generate multiple choice survey questions based on a given product prompt, send it to a targeted email list, and also provides a real-time analysis of the responses …


The Effect Of Metabolic Modulators On The Rate Of Steady State Water Exchange In S. Cerevisiae Grown In Chemostat Bioreactors, Samantha Mumford, Mark Woods, Johnathan Dutra May 2024

The Effect Of Metabolic Modulators On The Rate Of Steady State Water Exchange In S. Cerevisiae Grown In Chemostat Bioreactors, Samantha Mumford, Mark Woods, Johnathan Dutra

Student Research Symposium

Water transport across the lipid bilayer due to osmotic stress causes a change in intracellular volume over time. At isotonic equilibrium there is no change in cell volume and yet water exchange does not stop. Water molecules continue to exchange rapidly with those of the extracellular space. The rate constant for steady state water efflux (kio) can be measured using contrast enhanced magnetic resonance (MR) and the two-site exchange (2SX) model. kio is known to correlate with the cellular energy molecule ATP making it a probable biomarker for metabolic diseases such as cancer. Measurements of k …


Improving Tattle-Tale K-Deniability, Nicholas G.E. Morales May 2024

Improving Tattle-Tale K-Deniability, Nicholas G.E. Morales

Student Research Symposium

Ensuring privacy for databases is an ongoing struggle. While the majority of work has focused on using access control lists to protect sensitive data these methods are vulnerable to inference attacks. A set of algorithms, referred to as Tattle-Tale, was developed that could protect sensitive data from being inferred however its runtime performance wasn’t suitable for production code. This set of algorithms contained two main subsets, Full Deniability and K-Deniability. My research focused on improving the runtime or utility of the K-Deniability algorithms. I investigated the runtime of the K-Deniability algorithms to identify what was slowing the process down. Aside …


Integration Of Agent Models And Meta Reinforcement Learning (Meta-Rl) Algorithms For Car Racing Experiment, Vidyavarshini Holenarasipur Jayashankar May 2024

Integration Of Agent Models And Meta Reinforcement Learning (Meta-Rl) Algorithms For Car Racing Experiment, Vidyavarshini Holenarasipur Jayashankar

Student Research Symposium

Introduction: Achieving optimal performance in 2D racing games presents unique challenges, requiring adaptive strategies and advanced learning algorithms. This research explores the integration of sophisticated agent models with Meta Reinforcement Learning (Meta-RL) techniques, specifically Model-Agnostic Meta-Learning (MAML) and Proximal Policy Optimization (PPO), to enhance decision-making and adaptability within these simulated environments. We hypothesize that this innovative approach will lead to marked improvements in game performance and learning efficiency.

Methods: In our experimental setup, we applied MAML for its rapid adaptation capabilities and PPO for optimizing the agents' policy decisions within a 2D racing game simulator. The objective was …


Beavers Beyond Boundaries: Perceptions Of Beaver-Related Restoration, Matthew V. Guziejka May 2024

Beavers Beyond Boundaries: Perceptions Of Beaver-Related Restoration, Matthew V. Guziejka

Student Research Symposium

The study "Beavers Beyond Boundaries: Perceptions of Beaver-Related Restoration" conducted by Matt Guziejka and Heejun Chang from the WISE Lab, Department of Geography at Portland State University, delves into the social, cultural, and environmental dimensions of Beaver-Related Restoration (BRR) within the urban setting of the Tualatin River watershed. Utilizing a voluntary survey with 187 participants across three urban watershed sites, the research aimed to analyze community perceptions concerning beavers and their impact on the environment, particularly in relation to their proximity to watercourses. Findings indicate that proximity significantly affects attitudes towards beavers, with those living closer to watercourses demonstrating more …


Securing The Internet Of Things At Scale, Steven L. Willoughby May 2024

Securing The Internet Of Things At Scale, Steven L. Willoughby

Student Research Symposium

The world of the connected “Internet of Things” (IoT), including the "Industrial Internet of Things" (IIoT) is expanding to include more devices which observe and influence our daily lives, routines, locations, and even our state of health. But have the underlying protocols by which they communicate this data kept pace with the need to protect our privacy and security?

My talk will introduce my research into an approach to better secure this information flow using appropriate access controls without sacrificing performance. I will assess the historical challenges and simple access controls applied to IoT networking protocols and how they can …


Extreme Precipitation Climatology Of The Contiguous U.S., Amy M. Johnson May 2024

Extreme Precipitation Climatology Of The Contiguous U.S., Amy M. Johnson

Student Research Symposium

Extreme precipitation can cause flooding, landslides, loss of life and assets. Across the Contiguous United States (CONUS), concurrent to global warming, many communities have experienced increases in the amount of rain falling during the most extreme precipitation events and climate models project further increases for most of the CONUS. There is a need to comprehensively study the extreme precipitation climatology across the CONUS to understand what is within the observed range of extreme precipitation and the weather that drives it. Modern Era Retrospective analysis for Research and Applications 2 (MERRA-2) atmospheric reanalysis data for the period of 1980-2023 is used …


A Novel Caching Algorithm For Efficient Fine-Grained Access Control In Database Management Systems, Anadi Shakya May 2024

A Novel Caching Algorithm For Efficient Fine-Grained Access Control In Database Management Systems, Anadi Shakya

Student Research Symposium

Fine-grained access Control (FGAC) in DBMS is vital for restricting user access to authorized data and enhancing security. FGAC policies govern how users are granted access to specific resources based on detailed criteria, ensuring security and privacy measures. Traditional methods struggle with scaling policies to thousands, causing delays in query responses. This paper introduces a novel caching algorithm designed to address this challenge by accelerating query processing and ensuring compliance with FGAC policies. In our approach, we create a circular hashmap and employ different replacement techniques to efficiently manage the cache, prioritizing entries that are visited more frequently. To evaluate …


Recovery Of Black Carbon Concentrations In Burned Forests, Monica V. Zapata Villegas, Kelly E. Gleason May 2024

Recovery Of Black Carbon Concentrations In Burned Forests, Monica V. Zapata Villegas, Kelly E. Gleason

Student Research Symposium

Forest fires shed light absorbing particles (LAP), such as black carbon and burned woody debris, into snowpacks, darkening snow surface albedo, and advancing snowmelt timing and snow disappearance patterns for decades following fire. Although the role of LAPs in seasonal snow has been extensively studied in recent years, the spatiotemporal variability of LAPs and contributions to snowmelt relative to years since fire and burn severity is still unknown. In the Triple Divide region of western Wyoming, the headwaters of the Colorado, Columbia, and Missouri rivers, we quantified the spatiotemporal variability of forest fire effects on snow albedo, using geochemical analysis …


Development Of A Two-Photon Laser Scanning Microscope, Jess Hollenbaugh May 2024

Development Of A Two-Photon Laser Scanning Microscope, Jess Hollenbaugh

Student Research Symposium

The objective of this project was to convert a Sarastro 2000 confocal laser scanning microscope into a system capable of imaging using two-photon excitation (TPE) fluorescence for the use of the PSU biology department. TPE microscopy operates on the ability of fluorophores to accept two photons each with half the energy of a desired transition in a single quantum event via a virtual energy state and then emit a higher energy photon upon relaxation. This is preferable to single-photon excitation (SPE) due to the lower energy photons causing less damage to delicate biological samples. The adaptation process included physically altering …


The Influence Of Soil Composition On Stormwater Retention And Runoff In Green Roofs At Portland State, Manuel Edrozo, Lily Green, Mitchell Mcdonald, Nicholas Olmos May 2024

The Influence Of Soil Composition On Stormwater Retention And Runoff In Green Roofs At Portland State, Manuel Edrozo, Lily Green, Mitchell Mcdonald, Nicholas Olmos

Student Research Symposium

The purpose of this study is to determine what soil composition is best for green roofs at Portland State; we aim to compare the current soil to the original substrate, to measure which composition retains the most water, and which filters out the most pollutants in stormwater runoff. Five different soil compositions were tested — original, current, layered mixed, solid mixed, and potting soils — and 1,000mL of high and low intensity rainfall (in/hr) was simulated for each of the mixtures. Water was allowed to filter through the soils for a predetermined time (10min for a high application rate and …


Reed Research Reactor Neutron Beam Characterization And Analysis, Vee Bartko, Jerry Newhouse May 2024

Reed Research Reactor Neutron Beam Characterization And Analysis, Vee Bartko, Jerry Newhouse

Student Research Symposium

Using neutron activation analysis of 99% pure gold foils, the authors characterize the neutron dose and shape of the neutron beam at the Reed Research Reactor (RRR). The experimental procedure followed extensive modeling in Monte Carlo N-Particle (MCNP) and Tool for Particle Simulation (TOPAS) simulations, in which the beam was projected to be roughly collimated. The shape, defined in terms of neutron flux, was measured by placing the foils directly on top of the neutron beam cap at powers of 1, 5, and 10 kilowatts. The flux was then converted to neutron dose via the Nuclear Regulatory Commission's neutron fluence …


Textural Investigation Into Rapid Welding Transitions In The Tuff Of Leslie Gulch Along Succor Creek At The Mahogany Mountain-Three Fingers Rhyolite Field, Southeastern Oregon, Alicia J. Martinez-Garling, Martin J. Streck May 2024

Textural Investigation Into Rapid Welding Transitions In The Tuff Of Leslie Gulch Along Succor Creek At The Mahogany Mountain-Three Fingers Rhyolite Field, Southeastern Oregon, Alicia J. Martinez-Garling, Martin J. Streck

Student Research Symposium

The Mahogany Mountain-Three Fingers Rhyolite Field (MM-TFrf) in southeastern Oregon, associated with mid-Miocene rhyolite activity and Columbia River flood basalts, has been the subject of geological scrutiny. Previous studies proposed separate origins for the tuff of Leslie Gulch (LGT) and Spring Creek, but Benson and Mahood (2006) suggested a single ignimbrite event at 15.8 Ma, prompting a reassessment of MM-TFrf's history. This research focuses on LGT, investigating textural disparities between welded and non-welded tuff formations. Petrographic examinations delve into the transformation stages of pyroclastic tuff deposition, revealing the dynamic influences of volcanological and magmatic processes on welded and non-welded tuff …


Competing Supramolecular Forces: Boron Coordination Vs Π-Π Stacking, Sidhaesh A. Agarwal, Gonzalo Campillo-Alvarado, Nicholas Lutz, Jesus Daniel Loya, Eric W. Reinheimer May 2024

Competing Supramolecular Forces: Boron Coordination Vs Π-Π Stacking, Sidhaesh A. Agarwal, Gonzalo Campillo-Alvarado, Nicholas Lutz, Jesus Daniel Loya, Eric W. Reinheimer

Student Research Symposium

This study explores the impact of fluorination levels in azopyridine Lewis bases on their ability to direct the formation of B←N coordination adducts or cocrystals with phenylboronic ester. We hypothesize that the degree of fluorination can be used as a tool to control the outcome of supramolecular bonding competition, thus influencing complex self-assembly.

A series of azopyridines with varying degrees of fluorination were synthesized and reacted with phenylboronic ester. Their structures were analyzed using Hartree-Fock calculations, Hirshfeld surface analyses, and single crystal X-ray diffraction to assess the impact of fluorination on supramolecular interactions.

The study reveals that azopyridines with up …


Multiscale Variability Of Heavy Metals In A Western U.S. Snowpack, Kelsey Hefner May 2024

Multiscale Variability Of Heavy Metals In A Western U.S. Snowpack, Kelsey Hefner

Student Research Symposium

Natural and anthropogenically sourced particulates are deposited from the atmosphere to landscapes via dry and wet deposition, making frozen winter snowpack a natural archive of atmospheric elemental composition. Wildfires in the Western United States are increasing in extent, duration, and severity, especially in alpine regions. Severe fires remove forest canopy and can impact how atmospheric elements are dispersed and stored across snow-dominated watersheds. We evaluated Al, V, Cr, Mn, Ni, Cu, As, Zn, Se, Mo, Cd, and Pb concentrations in 394 winter snow core samples. We collected samples in 2019 and 2020 from a chronosequence of eight forests that burned …


Neutron Time Of Flight Spectrometry As A Diagnostic Tool For Inertial Electrostatic Confinement Fusion Plasmas, Andrew H. Dempsey, Erik J. Sanchez May 2024

Neutron Time Of Flight Spectrometry As A Diagnostic Tool For Inertial Electrostatic Confinement Fusion Plasmas, Andrew H. Dempsey, Erik J. Sanchez

Student Research Symposium

Inertial electrostatic confinement (IEC) is a method for achieving fusion of light nuclei wherein ions are injected into a spherically symmetric system of concentric electrodes. When the innermost electrode is held at negative high voltage with respect to the outer electrode, ions injected into the reactor at cathode (ground) potential accelerate toward the anode where they may undergo collisions with sufficient energy to overcome Coulomb repulsion and achieve nuclear fusion. The most commonly used IEC fusion fuels are deuterium-deuterium (D-D) and deuterium-tritium (D-T). Both fuels undergo fusion reactions that result in production of fast neutrons with distinct energies. Neutron production …


Wildland Urban Interface Growth And Development Potentials In Deschutes County, Samantha Hall May 2024

Wildland Urban Interface Growth And Development Potentials In Deschutes County, Samantha Hall

Student Research Symposium

Policy can and has been used as a tool to reduce the risk communities experience from natural hazards by limiting development in areas most vulnerable. How and where development occurs directly influences the amount of risk a community experiences from natural hazards like hurricanes, earthquakes, flash floods, and wildfire among others. Development patterns that contribute to increased wildfire risk mostly occur within the wildland urban interface, a land use type where development is at the fringes or intercept of wildland areas and is more flammable due to surrounding vegetation, slope, local climate, and other factors. For this research, Deschutes County …


Computationally Assisted Mechanistic Analysis Of The Protonolysis Of A Pt–Me Bond, Clement Dasilva May 2024

Computationally Assisted Mechanistic Analysis Of The Protonolysis Of A Pt–Me Bond, Clement Dasilva

Student Research Symposium

Mechanistic study of the protonolysis of (cod)PtMe2 could give insight into the activation of C-H bonds by platinum because it is the microscopic reverse reaction. Two possible mechanisms for the protonolysis of dimethyl platinum complexes have been proposed, with experimental and computational data supporting the single step, SE2, over the multistep, SE(ox) mechanism. New experimental work from our group supports a multi-step mechanism with multiple acid molecules. In this work, the SE2 mechanism as well as a proposed SE(ox) mechanism were computationally modeled with a single equivalent of acid, TFAH, and two equivalents using density functional theory. The modeled pathways …


Method Validation Of Metals In Environmental Soil Samples, Sofia Deangelis, Nana Nguyen May 2024

Method Validation Of Metals In Environmental Soil Samples, Sofia Deangelis, Nana Nguyen

Student Research Symposium

Vehicles are a major source of metal accumulation in terrestrial environments. Green infrastructure, such as bioswales, has been implemented as a way to mitigate this damage. However, there is a limited understanding of the processes that occur in these bioswales as few go back after implementation to identify areas in the bioswale with accumulation of pollutants. Inductively coupled mass spectrometry (ICP-MS) has the potential to be used in this type of study due to the machine’s high sensitivity and selectivity. However complications can arise while using the ICP-MS to characterize complex environmental samples. This study seeks to optimize microwave assisted …