Physical Sciences and Mathematics Commons^™

Hydrologic Modeling With Remote Sensing For The Estimation Of Groundwater Resources Within The Sand River Catchment, South Africa, Sophia Bakar

Electronic Theses and Dissertations

The Sand River Catchment is an important tributary of the transboundary Limpopo River in South Africa, which spans Botswana, Mozambique, South Africa, and Mozambique. Groundwater is a critical resource in the region, especially in the context of population growth and climate change. Data are needed for proper management of these water resources. In regions where groundwater data are sparse in time, space, or both, the most promising solutions come from satellites and hydrologic models. Regional literature suggests that the Soutpansberg Mountains, located within the Sand Catchment, are high-elevation water towers with uncertain groundwater resources. Improved understanding of groundwater resources in …

Assessments Of Water Chemistry And Fish Community Structure In The Buffalo Creek Watershed, Tributary To The Allegheny River In Armstrong And Butler Counties, Pennsylvania, Kathleen Wilson

Electronic Theses and Dissertations

The Buffalo Creek watershed has experienced water quality impairments for various reasons, including but not limited to, agricultural influence, abandoned mine drainage (AMD), on-site wastewater malfunction, and stormwater. The source and cause of the most prevalent impaired areas remains unknown. The goal of this study was to analyze water chemistry using state water quality standards and mass ratio analysis, then to conduct fish community analysis. We found toxic metal pollution across the watershed, with iron, cadmium, copper, and selenium frequently exceeding criteria. We determined which streams are polluted by resource extraction activities by conducting mass ratio analysis. We found conventional …

Gold (I) Tetrathiomolybdate Clusters: Synthesis, Characterization, Computational Studies, And Reactivity With Thiophenol And Selenophenol, Dhirgam Humaidy

Electronic Theses and Dissertations

This thesis describes the synthesis and reactivity of heterometallic complexes containing medicinally active Au(I) and tetrathiomolybdate, [MoS₄]^2-. The research is motivated by the idea of multifunctional drugs, which are designed to treat diseases through two or more mechanisms of action. Five clusters of the general form, [MoS₄(AuL)₂] were prepared: C-1 (L=IPr), C-2 (L=IBzMe), C-3 (L=IMes), C-4 (L=PPh₃), and C-5 (L=PEt₃). The clusters with NHC ligands, C-1, C-2, and C-3 were prepared for the first time and thoroughly characterized by ¹H NMR,¹³C{¹H} …

Secondhand Shopping Is Now The Coolest Way To Get Your Clothes, Camryn Quick

Capstones

Shopping secondhand has experienced an uptick in popularity in the past few years. There are a few reasons for this, all of which are examined in the project. One reason for the increase in secondhand shoppers is the daunting news about the state of our environment. Another reason, perhaps even more powerful than the fear of environmental collapse, is that thrifting has become a fashion phenomenon showcased and distributed throughout social media apps like TikTok. Essentially, shopping secondhand has become cool. This project explores these driving forces behind the thrifting boom, as well as the possible impacts, including "thrift store …

To Destroy Or Transform? Two Fossil Fuel Transitions Offer Glimpse Into Industry’S Future, Chloe Bennett, Sarah Kerson

Capstones

In 2019, the Philadelphia Energy Solutions oil refinery closed after a dangerous explosion. But for years before the accident, members of the local environmental justice organization Philly Thrive had been advocating for its closure. Neighborhood residents who live near the refinery site had been complaining for years of health problems, ranging from asthma to cancer. “Enough is enough,” says Sylvia Bennett, 79, who lives in the Grays Ferry neighborhood near where the refinery is located. Her two daughters have both been diagnosed with cancer.

What will become of the refinery site remains to be seen as conversations between Hilco and …

Interpretable Network Representations, Shengmin Jin

Dissertations - ALL

Networks (or interchangeably graphs) have been ubiquitous across the globe and within science and engineering: social networks, collaboration networks, protein-protein interaction networks, infrastructure networks, among many others. Machine learning on graphs, especially network representation learning, has shown remarkable performance in network-based applications, such as node/graph classification, graph clustering, and link prediction. Like performance, it is equally crucial for individuals to understand the behavior of machine learning models and be able to explain how these models arrive at a certain decision. Such needs have motivated many studies on interpretability in machine learning. For example, for social network analysis, we may need …

Acetylacetone Oxidation At Room Temperature: A Multiplexed Photoionization Mass Spectrometric Investigation, Study Of The Russell Intermediates In Gas Phase Reactions, And The Investigation Of Oxidation Reaction Products Of Ethanol At Room Temperature, Sara Gallarati

Master's Theses

This thesis presents the combustion study of acetyl acetone using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at 298 K. The experiments were performed at the Chemical Dynamics Beamline 9.0.2 at the Advanced Light Source of the Lawrence Berkeley National Laboratory. The reaction of acetyl acetone with chlorine (Cl) radicals was analyzed based on their photoionization spectra and reaction kinetic profiles.

Additionally, a study of the Russell intermediate has been performed. Previous to experimentation at the Advanced Light Source, computational analysis has been investigated to evaluate compounds that could possibly lead to the formation of a stable species. The …

Understanding The Impacts Of Anthropogenic Effects An Habitat Variability Interactions On Maine's Rocky Intertidal Ecosystem, Laura Braun

Electronic Theses and Dissertations

The rocky intertidal ecosystem is an important ecological and cultural aspect of the picturesque Maine coast, playing a vital role in not only Maine’s coastal ecosystem, but also to Maine’s economy. It’s distinct community structure along the sharp elevational gradient and the presence of daily stressors (wave action, heat, and desiccation), make the rocky intertidal ecosystem an important model ecosystem to monitor for effects from anthropogenic impacts. In this thesis, I describe attempts to monitor and understand the impacts of two of these anthropogenic impacts on this system: climate change and industrial harvesting of Ascophyllum nodosum along Maine’s coast. For …

Speciated Isotope Dilution Mass Spectrometry In Combination With Thor’S Hammer Metaspike Technology For The Assessment Of Low-Level Biomarkers For Human Health Evaluation, Ashley Ebert

Electronic Theses and Dissertations

Our research team has been focused on quantifying important biological analytes in human blood samples to delineate the biochemical processes underlying certain states of dysfunction and evaluate treatment efficacy. These efforts have been guided by laboratory measurements with the input of medical experts. Speciated isotope dilution mass spectrometry (SIDMS) explained in detail in EPA Method 6800 has been successfully applied in the quantification of an important biomarker analyte for immune function and detoxification processes: glutathione. Past research has proven the molecule a biomarker for autism spectrum disorder (ASD) in the form of the reduced/oxidized glutathione (GSH/GSSG) ratio, and literature has …

Quantum Computations And Molecular Dynamics Simulations: From The Fundamentals Of Antimicrobial Resistance To Neurological Diseases, Angel Tamez

Electronic Theses and Dissertations

Biophysical phenomena are modeled using a combination of quantum and classical methods to interpret and supplement three distinct and diverse problems in this dissertation. In the first project, decarboxylation reactions are ubiquitous across chemical and biological disciplines, yet the origin of non-catalytic solvent effects remains elusive. Specific solvent structure and energetics have not been well described for the monoanion of malonate, nor corrected from the gas-phase charge-assisted intramolecular hydrogen bond model known as “pseudochair”. In the aqueous phase, a low-lying energy conformer known as the “orthogonal conformation” is computed to be preferred by a three-water cluster of hydrogen bonding over …

Utilizing Remote Sensing Technology To Relocate Lubra Village And Visualize Flood Damages, Ronan Wallace

Mathematics, Statistics, and Computer Science Honors Projects

As weather patterns change worldwide, isolated communities impacted by climate change go unnoticed and we need community and habitat-conscious solutions. In Himalayan Mustang, Nepal, indigenous Lubra village faces threats of increasing flash flooding. After every flood, residual concrete-like sediment hardens across the riverbed, causing the riverbed elevation to rise. As elevation increases, sediment encroaches on Lubra’s agricultural fields and homes, magnifying flood vulnerability. In the last monsoon season alone, the village witnessed floods swallowing several fields and damaging two homes. One solution considers relocating the village to a new location entirely. However, relocation poses a challenging task, as eight centuries …

Coordination Chemistry Of Uranyl Ions With Surface-Immobilized Peptides: An Xps Study, Esha Mishra, Cody M. Schultz, Rebecca Lai, Peter A. Dowben

Department of Physics and Astronomy: Faculty Publications

The coordination chemistry of uranyl ions with surface immobilized peptides was studied using X-ray photoemission spectroscopy (XPS). All the peptides in the study were modified using a six-carbon alkanethiol as a linker on a gold substrate with methylene blue as the redox label. The X-ray photoemission spectra reveal that each modified peptide interacts differently with the uranyl ion. For all the modified peptides, the XPS spectra were taken in both the absence and presence of the uranium, and their comparison reveals that the interaction depends on the chemical group present in the peptides. The XPS results show that, among all …

First-Row Transition Element Distribution Across The Blueschist-Eclogite Transition: A Case Study From New Caledonia, Natalie M. Harmon

Electronic Theses and Dissertations

The first-row transition elements (FRTE), namely Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, are potential redox tracers in the solid Earth due to their general compatibility during crustal processes, and the redox-sensitive nature of certain elements. Despite widespread interest in the FRTEs, their distribution and behavior in subduction zones, particularly across the blueschist-eclogite transition, are still poorly constrained. New Caledonia preserves a prograde subduction zone with largely coherent continuous progression in metamorphic grade. Although the metamorphic sequence has been disrupted to some extent, this is the closest natural example of blueschist and eclogite that was sourced …

Carbon Dioxide Emissions From Deadwood In Forests Of The Northeastern United States, Zoe Read

Electronic Theses and Dissertations

As the climate changes, understanding the sources and sinks of greenhouse gases such as carbon dioxide (CO₂) is increasingly important. However, several components of the carbon cycle within forests remain poorly understood. For example, knowledge gaps exist in our understanding of CO₂ emissions from coarse woody material (CWM; logs and stumps), including how emissions change over time, how they are influenced by environmental variables, and how they compare to soil and ecosystem-level CO₂ emissions.

To fill these knowledge gaps, we examined CO₂ emissions from CWM at three sites. We sampled 18 red spruce (Picea …

Investigation Of Cryptotephra In Polar Ice Cores, Meredith Helmick

Electronic Theses and Dissertations

Volcanic ash (tephra) present within polar ice cores greatly supplements our understanding of past volcanism and its impacts on society and the state of the climate system. This thesis investigates the utility and limitations of ice core tephrochronology in answering questions related to volcanic source identification of ice core glaciochemical signals, tephrostratigraphy of an Antarctic ice core, and the timing of major and climate forcing eruptions. This thesis explores the efficacy of SEM-EDS measurements on ultra-fine (µm) volcanic particles for the purpose of geochemically characterizing a non-visible ice-embedded tephra and the subsequent identification of the volcanic source. In combination with …

Regional Scale Generalizations Of Firn Thickness And Snow Accumulation In Southeast Alaska: An Applied Deep Learning Framework, Jonathan Maurer

Electronic Theses and Dissertations

High elevation mountain glaciers are referred to as the “water towers of the world” due to their ability to store water internally and release it later through melt and runoff. Much of the work to understand these complex environments has focused on cold based polar glaciers in high latitude regions, neglecting temperate glaciers and associated snowpack which are more responsive than polar systems to minor climatic changes. Advancements in the availability of open source data, deep learning theory, and computational efficiency has opened up new methods of “data hungry” modeling that may be well suited to the type of complex …

Chemical Elements, Flavor Chemicals, And Nicotine In Unused And Used Electronic Cigarettes Aged 5–10 Years And Effects Of Ph, Monique Williams, Wentai Luo, Kevin J. Mcwhirter, Omeka Ikegbu, Prue Talbot

Chemistry Faculty Publications and Presentations

The concentrations of elements/metals, nicotine, flavor chemicals and acids were compared in the e-liquids of unused and used first-generation electronic cigarettes (ECs) that were stored for 5–10 years. Metal analysis was performed using inductively coupled plasma optical emission spectroscopy; nicotine and flavor chemical analyses were performed using gas chromatography/mass spectroscopy. Of the 22 elements analyzed, 10 (aluminum, chromium, copper, iron, lead, nickel, selenium, silicon, tin, zinc) were often found in the e-liquids. Five elements had the highest average concentrations: copper (1161.6 mg/L), zinc (295.8 mg/L), tin (287.6 mg/L), nickel (71.1 mg/L), and lead (50.3 mg/L). Nicotine concentrations were always lower …

Bio-Based Uv-Curable Films And The Effect Of Bio-Content On The Properties Of The Films, Sahilkumar Chaudhary

Electronic Theses & Dissertations

The use of renewable resources in film formation has become a new focal point for industry because it is abundantly available and has less carbon emission during production than traditional ones. This has drawn researchers to investigate the functionality of bio-based raw materials and their end-usage. By modifying their chemical structures, the properties of these films like thermal resistance, impact resistance, and chemical resistance can be increased. In this research, limonene was used as a partial replacement for petroleum-based chemicals in film formation. A two-step chemical process was carried out to modify the limonene and the final product was used …

Sunflower Oil-Based Polyol In Flame-Retardant Rigid Polyurethane Foams, Magdalene Asare

Electronic Theses & Dissertations

The current shift from solely depending on petroleum sources to seeking renewable alternatives is due to their fast depletion, spike in prices, and the need to reduce our carbon footprint. For instance, the polyurethane industry currently calls for renewable and less toxic polyols and isocyanates for their synthesis over the traditionally used ones. To tackle an aspect of this matter, this work investigates the generation of polyol from sunflower oil, and further probes their use in rigid foams, one of the widely utilized polyurethanes. Epoxidation and ring-opening reactions were used to convert the sunflower oil into a more reactive form, …

Analyzing The Effects Of Climate Impacts In El Salvador And How They Influence Pollution, Ecosystems And Communities, Veronica Norio-Tomasino

Master's Projects and Capstones

Due to projections of rising temperatures and increased frequency and severity of extreme weather events, the rate at which climate change is impacting nations is devastating. However, developing countries and vulnerable communities are not the primary contributors to climate change, but they are at a greater risk for climate impacts by industrialized nations. As a result of increased human activity, developing nations such as El Salvador are particularly susceptible to climate-related events. Deforestation, water pollution, and human health risks are some activities that have contributed to El Salvador's vulnerability to climate change, drastically affecting rural communities suffering from multidimensional poverty. …

Evaluating Equity In Transportation Greenhouse Gas Emission Reduction Strategies In Local Climate Action Planning In Oakland, California, Eliza J. Kane

Master's Projects and Capstones

Emissions from California’s transportation sector contribute to global climate change and impact local air quality and public health. Forty-one percent of California’s greenhouse gas emissions in 2019 were from transportation. Transportation emissions are also a source of many health-harming air pollutants such as carbon monoxide, volatile organic compounds, and particulate matter. Disadvantaged communities in California experience disproportionate impacts from transportation emissions and suffer worse health effects, including higher incidences of asthma, cardiovascular disease, and premature death. Cities have led the way in policymaking to mitigate and adapt to climate change, including creating Climate Action Plans (CAPs) to propose strategies to …

Anthropogenic Effects On Tidal Distortion In A Tidal River, Matthew D. Fischer

Electronic Theses and Dissertations

Tidal rivers are landward portions of estuarine systems constituting the union between coastal, tidally controlled settings and rivers, where fluvial processes dominate. In these reaches, river discharge (mean flow) and tides are the two most important mechanisms in controlling geophysical flows. The processes governing water levels and current amplitudes in tidal rivers are highly nonlinear and modulated by external forcings- thus requiring sophisticated techniques for accurate prediction and forecasting. Physical oceanographers and estuarine physicists tend to limit their study area to the maximum extent of the horizontal tide (salinity intrusion), not the most landward point influenced by tidal water levels. …

Holocene And Last Glacial Period Atmospheric Dynamics And Biogeochemistry Based On South Pole Ice Core Microparticle And Trace Element Records, Aaron Chesler

Electronic Theses and Dissertations

I develop and interpret a record of dust deposition from the South Pole ice core (SPC14) to identify changes in atmospheric variability. The SPC14 core was drilled during 2014 – 2016 and provides a high accumulation (~7 cm w.e.q. per year) record in central Antarctica that reaches a depth of 1751 m (~54 ka). My analysis combines microparticle (dust) concentration, size, and shape metrics using continuous and discrete methodologies and high- and low-resolution multifractional Fe analyses that span the past 54 ka.

Results from my dust shape analysis suggest the common assumption of spherical dust particle shape in incorrect and …

Barriers To And Opportunities For Adoption In Maine’S Aquaculture Industry, Caitlin Cleaver

Electronic Theses and Dissertations

Aquaculture, or the farming of marine species, can diversify coastal economies, but development of this industry is hindered by negative perceptions or regulatory constraints. Commercial fishers are logical adopters of aquaculture, but can also mount opposition to its growth. This dissertation utilized innovation theory to understand fishers’ perceptions of and willingness to adopt aquaculture and drivers of and barriers to scallop aquaculture development in Maine (USA). Through a mail survey, lobster fishers’ perceptions of Maine’s aquaculture industry and their willingness to adopt aquaculture were assessed (Chapter 2). Individuals who were more satisfied with government management of aquaculture held more positive …

Possible Overestimation Of Nitrogen Dioxide Outgassing During The Beirut 2020 Explosion, Ashraf Farahat, Nayla El-Kork, Ramesh P. Singh, Feng Jing

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

On 4 August 2020, a strong explosion occurred near the Beirut seaport, Lebanon and killed more than 200 people and damaged numerous buildings in the vicinity. As Amonium Nitrate (AN) caused the explosion, many studies claimed the release of large amounts of NO₂ in the atmosphere may have resulted in a health hazard in Beirut and the vicinity. In order to reasonably evaluate the significance of NO₂ amounts released in the atmosphere, it is important to investigate the spatio-temporal distribution of NO₂ during and after the blast and compare it to the average day-to-day background emissions from …

Plasma-Assisted Growth And Characterization Of Piezoelectric Aln And Sc(X)Al(1-X)N Films For Microwave Acoustic Sensor Applications, Morton Greenslit

Electronic Theses and Dissertations

The use of surface acoustic wave (SAW) sensors in high temperature harsh environments such as those found in power plants, industrial manufacturing, or aerospace applications allows for monitoring of internal conditions at locations where traditional sensors do not operate or are unreliable. Surface acoustic wave resonator (SAWR) sensors are based on piezoelectric materials and feature a small passive low-profile self-powered design that can operate and wirelessly transmit data to monitor parameters such as temperature, pressure, or strain. SAWR sensors typically consist of a series of metal electrodes fabricated onto a bulk crystal piezoelectric such as langasite (La3Ga5SiO14). However, there are …

Pyseg: A Python Package For 2d Material Flake Localization, Segmentation, And Thickness Prediction, Diana B. Horangic

Student Research Projects

Thin materials are of interest for their extraordinary physical, mechanical, thermal, electrical, and optical properties. Monolayers and bilayers of 2D materials can be manufactured through a variety of exfoliation methods. To determine layer thickness, Raman spectroscopy or other methods like Rayleigh scattering are used. These methods are, however, slow, and they require equipment beyond an optical microscope. A Python package that automates flake identification processes was built, with access solely to RGB data from an optical microscope assumed. My package, pyseg, localizes flakes on a substrate and then makes a rough estimate of their thickness from first principles. It can …

Uncertainty Of Icesat-2 Atl06- And Atl08-Derived Snow Depths For Glacierized And Vegetated Mountain Regions, Ellyn M. Enderlin, Colten M. Elkin, Madeline Gendreau, H.P. Marshall, Shad O'Neel, Christopher Mcneil, Caitlyn Florentine, Louis Sass

Geosciences Faculty Publications and Presentations

Seasonal snow melt dominates the hydrologic budget across a large portion of the globe. Snow accumulation and melt vary over a broad range of spatial scales, preventing accurate extrapolation of sparse in situ observations to watershed scales. The lidar onboard the Ice, Cloud, and land Elevation, Satellite (ICESat-2) was designed for precise mapping of ice sheets and sea ice, and here we assess the feasibility of snow depth-mapping using ICESat-2 data in more complex and rugged mountain landscapes. We explore the utility of ATL08 Land and Vegetation Height and ATL06 Land Ice Height differencing from reference elevation datasets in two …

Socio‑Economic Inequalities In Minimum Dietary Diversity Among Bangladeshi Children Aged 6–23 Months: A Decomposition Analysis, Satyajit Kundu, Pranta Das, Ashfikur Rahman, Hasan Al Banna, Kaniz Fatema, Akhtarul Islam, Shobhit Srivastava, T. Muhammad, Rakhi Dey, Ahmed Hossain

Department of Statistics: Faculty Publications

This study aimed to measure the socio-economic inequalities in having minimum dietary diversity (MDD) among Bangladeshi children aged 6–23 months as well as to determine the factors that potentially contribute to the inequity. The Bangladesh Demographic and Health Survey (BDHS) 2017–2018 data were used in this study. A sample of 2405 (weighted) children aged 6–23 months was included. The overall weighted prevalence of MDD was 37.47%. The concentration index (CIX) value for inequalities in MDD due to wealth status was positive and the concentration curve lay below the line of equality (CIX: 0.1211, p < 0.001), where 49.47% inequality was contributed by wealth status, 25.06% contributed by the education level of mother, and 20.41% contributed by the number of ante-natal care (ANC) visits. Similarly, the CIX value due to the education level of mothers was also positive and the concentration curve lay below the line of equality (CIX: 0.1341, p < 0.001), where 52.68% inequality was contributed by the education level of mother, 18.07% contributed by wealth status, and 14.69% contributed by the number of ANC visits. MDD was higher among higher socioeconomic status (SES) groups. Appropriate intervention design should prioritize minimizing socioeconomic inequities in MDD, especially targeting the contributing factors of these inequities.

Predictors Of Covid-19 Vaccination Rate In Usa: A Machine Learning Approach, Syed M. I. Osman, Ahmed Sabit

WCBT Faculty Publications

In this study, we examine state-level features and policies that are most important in achieving a threshold level vaccination rate to curve the effects of the COVID-19 pandemic. We employ CHAID, a decision tree algorithm, on three different model specifications to answer this question based on a dataset that includes all the states in the United States. Workplace travel emerges as the most important predictor; however, the governors’ political affiliation (PA) replaces it in a more conservative feature set that includes economic features and the growth rate of COVID-19 cases. We also employ several alternative algorithms as a robustness check. …