Physical Sciences and Mathematics Commons^™

Exploring The Effects Of Microplastics On Marine Biota, Meredith Evans Seeley

Dissertations, Theses, and Masters Projects

There is mounting evidence that microplastics are a persistent and increasing hazard for aquatic organisms. The effects of microplastics on organisms and ecosystems are complex, however, and may be linked to a wide variety of particle characteristics including size, shape, polymer, additive chemistry, and degree of weathering. Assessing risk is complicated by the fact that many known effects of microplastics are sublethal, and that plastics have been postulated to interact with other stressors, such as pathogens. The work presented here expands our understanding of these complex effects. First, the impacts of microplastics on sedimentary microbial ecosystems and biogeochemical carbon and …

Quantum Sensing For Low-Light Imaging, Savannah Cuozzo

Dissertations, Theses, and Masters Projects

In high-precision optical measurements, noise due to quantum fluctuations in the amplitude and phase of the probing field becomes the limiting factor in detection sensitivity. While this quantum noise is fundamental and not a result of detection, it is possible to engineer a quantum state that has reduced noise in either amplitude or phase (at the cost of increasing noise in the other) called a quadrature-squeezed state. In this dissertation, we study the use of quadrature-squeezed vacuum states for low-light imaging and develop a quantum detection method to measure the spatial dependence of the quantum noise using a camera instead …

Deep Learning From Space: Methods & Applications In High-Resolution Satellite Imagery Analysis, Ethan Brewer

Dissertations, Theses, and Masters Projects

Satellite imagery analysis using deep learning methods, specifically convolutional neural networks (CNNs), has grown in popularity since 2012, with uses extending into the estimation of population, wealth, poverty, conflict, migration, education, and infrastructure, among other applications. This dissertation contributes to this body of literature in three parts. First, I explore the use of deep learning to overcome the sparsity, or complete lack, of accurate information regarding existing road infrastructure across much of the world. Using a novel labeled dataset generated by a custom-coded Android application, I show that a transfer learning approach can estimate road quality based on high-resolution satellite …

Investigation Of Stripes, Spin Density Waves And Superconductivity In The Ground State Of The Two-Dimensional Hubbard Model, Hao Xu

Dissertations, Theses, and Masters Projects

The Hubbard model is a "paradigmatic" model in the realm of condensed matter physics. Recently a work with various state-or-art methods established the ground state stripe order near 1/8 doping and strong on-site interaction. Therefore, in this thesis, we determine the spin and charge order of ground state of 2D doped Hubbard model in its simplest form (with only on site repulsion and nearest-neighbor hoping) with various doping and small to medium interaction. At half-filling, the ground state is known to be an antiferromagnetic Mott insulator. Doping Mott insulators is believed to be relevant to the superconductivity observed in cuprates. …

Enabling Practical Evaluation Of Privacy Of Commodity-Iot, Sunil Manandhar

Dissertations, Theses, and Masters Projects

There has been a massive shift towards the use of IoT products in recent years. While companies have come a long way in making these devices and services easily accessible to the consumers, very little is known about the privacy issues pertaining to these devices. In this dissertation, we focus on evaluating privacy pertaining to commodity-IoT devices by studying device usage behavior of consumers and privacy disclosure practices of IoT vendors. Our analyses consider deep intricacies tied to commodity-IoT domain, revealing insightful findings that help with building automated tools for a large scale analysis. We first present the design and …

Importance Of Muddy Bed Aggregate Processes In Cohesive Sediment Dynamics Associated With Sediment Management Projects, David Perkey

Dissertations, Theses, and Masters Projects

The erosion and transport processes of fine sediment is largely impacted by the aggregation state. Understanding fine sediment transport processes is a key component to managing the nation’s navigation channels, ports, and reservoirs. To improve its ability to apply management strategies related to fine sediments, the USACE has undertaken research that focusses on the aggregation state of fine sediment. Of particular interest is the ability to expand the use of fine-grained sediment in projects that seek to beneficially use dredge material. In this study, a newly developed camera system was used to evaluate the aggregation state of eroded sediment from …

Physiological Condition And Recruitment Of Mytilus Edulis And Donax Variabilis On Virginia Barrier Islands, Taylor Walker

Dissertations, Theses, and Masters Projects

Climate change has caused gradual changes within marine environments within the last couple decades and is expected to continue to impact these ecosystems. Changes to these ecosystems are anticipated to emerge as adverse effects reach the lowest and highest levels within trophic food webs. For example, these environmental changes may change the abundance and distribution of species within their current geographic range. In extreme cases, climate change has already resulted in range shifts of terrestrial and marine species. A need for bioindicator species has emerged, so that they may be used to indicate when climate change may impact marine communities …

Communication And Computation Efficient Deep Learning, Zeyi Tao

Dissertations, Theses, and Masters Projects

Recent advances in Artificial Intelligence (AI) are characterized by ever-increasing datasets and rapid growth of model complexity. Many modern machine learning models, especially deep neural networks (DNNs), cannot be efficiently carried out by a single machine. Hence, distributed optimization and inference have been widely adopted to tackle large-scale machine learning problems. Meanwhile, quantum computers that process computational tasks exponentially faster than classical machines offer an alternative solution for resource-intensive deep learning. However, there are two obstacles that hinder us from building large-scale DNNs on the distributed systems and quantum computers. First, when distributed systems scale to many nodes, the training …

Environmental Justice In The Elizabeth River Watershed: Exploring The Utility Of Environmental Justice Screening Tools, Julianna M. Ramirez

Dissertations, Theses, and Masters Projects

The Environmental Justice (EJ) movement has long highlighted the disproportionate exposure to environmental hazards experienced by Black, Indigenous, People of Color (BIPOC) and low-income communities across the country. Environmental practitioners have recently focused on utilizing EJ screening tools, which combine environmental and social data to visualize vulnerable communities, to begin to address environmental injustice rampant in BIPOC and low-income communities. This project explores EJ theoretical frameworks and the historical context of social oppression and environmental pollution in the Elizabeth River watershed (ERW) of Virginia to: 1) understand the social, political, and economic context behind environmental injustice; and 2) generate goals …

Sediment Survey: Yr060822, Station 3916, Clay Bank, York River Virginia, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Sediment Survey: Yr070523, Station 3939, Clay Bank, York River Virginia, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Sediment Survey: Yr060925, Station 3918, Gloucester Point, York River Virginia, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Sediment Survey: Yr070810, Station 3945, Gloucester Point, York River Virginia, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Tower Deployment: Yr130313 To Yr130426, Adv, Clay Bank, York River Virginia, Grace M. Massey, Kelsey A. Fall, Carl T. Friedrichs

Data

Dataset consists of data collected during a tower deployment of four Nortek Vector ADV sensors which were mounted at different depths in the water column to monitor suspended sediment concentrations and sizes. Conductivity and temperature were also monitored at corresponding depths.

Tower Deployment: Yr160831 To Yr160912, Lisst, Clay Bank, York River Virginia, Grace M. Massey, Kelsey A. Fall, Carl T. Friedrichs

Data

Dataset consists of data collected during a tower deployment of a Sequoia LISST 100-ST sensor in the surface waters to monitor suspended sediment concentrations and sizes.

Tripod Deployment: Yr131211 To Yr140225, Adv, Clay Bank, York River Virginia, Grace M. Massey, Carl T. Friedrichs

Data

Dataset consists of burst data collected as part of a tripod deployment. The tripod included the following instruments: Acoustic Doppler Velocimeter (ADV), RBR CTD, Sediment Trap.

Tripod Deployment: Yr140404 To Yr140717, Adv, Clay Bank, York River Virginia, Grace M. Massey, Carl T. Friedrichs

Data

Dataset consists of burst data collected as part of a tripod deployment. The tripod included the following instruments: Acoustic Doppler Velocimeter (ADV), two HOBOs, Sediment Trap.

Storm Surge Simulation From The 2009 Nor’Easter On The Virginia Shoreline, Karinna Nunez, Yinglong J. Zhang, Evan Hill, Catherine Riscassi Duning

Data

The November 2009 nor’easter formed from the remnants of Hurricane Ida and generated strong winds, heavy rain, and storm surge across the east coast of the United States. The height of the storm surge generated by the nor’easter was modelled throughout Virginia using SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model). SCHISM outputs were translated to GIS and processed to be overlaid upon the LUBC (land use and bank cover) shoreline of coastal Virginia.

Coastal Virginia Flooding Duration Maps Current And Projected For 2020, 2050 And 2100, Molly Mitchell, Daniel Schatt, Jessica Hendricks

Data

Geospatial layers displaying annual flooding duration in the coastal zone of Virginia. These were generated from publicly available historical hourly tidal data from the NOAA Tides and Currents website from various tide gauges in the Chesapeake Bay region for the last 20 years. Particular tide gauges were linked to specific localities depending on location. The data was processed to determine average annual flooding duration at various flooding levels. Flood levels corresponding to specified average annual duration levels were then determined and used with lidar-derived digital elevation models to extract flood areas corresponding to the specified ranges of flood duration. Specifically, …

Partial Wave Analysis Of Strange Mesons Decaying To K + Π − Π + In The Reaction Γp → K + Π + Π − Λ(1520) And The Commissioning Of The Gluex Dirc Detector, Andrew Hurley

Dissertations, Theses, and Masters Projects

Hadron spectroscopy is a cornerstone of our understanding of the strong nuclear interac-tions. Studying the hadron spectrum led to the postulation of quarks and gluons, and the development of Quantum Chromodynamics (QCD), the theory of the strong nuclear force. Today hadron spectroscopy provides an important test of QCD, particularly in the non-perturbative energy regime. One such test is the existence of hybrid hadrons that have gluonic degrees of freedom, e.g. qq̄g states, that are allowed by QCD but have remained elusive in experimental searches. The GlueX experiment located at Thomas Jefferson National Accelerator Facility, is designed to map the light …

Sediment Survey: Yr110518, Station S4914-S4918, Clay Bank, York River Virginia, Grace M. Massey, Kelsey A. Fall, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Sediment Survey: Yr120712, Station S5022-S5025, Clay Bank, York River Virginia, Grace M. Massey, Kelsey A. Fall, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Sediment Survey: Yr061120, Station 3924, Gloucester Point, York River Virginia, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Tripod Deployment: Yr110506 To Yr110705, Adv, Clay Bank, York River Virginia, Grace M. Massey, Carl T. Friedrichs

Data

Dataset consists of burst data collected as part of a tripod deployment. The tripod included the following instruments: Two Acoustic Doppler Velocimeters (ADV), YSI6600 CTD.

Tripod Deployment: Yr120319 To Yr120706, Adv, Clay Bank, York River Virginia, Grace M. Massey, Carl T. Friedrichs

Data

Dataset consists of burst data collected as part of a tripod deployment. The tripod included the following instruments: Acoustic Doppler Velocimeter (ADV), Sediment Trap.

Marsh Vulnerability Index And Index Applied To Coastal Shorelines, Molly Mitchell, Donna Marie Bilkovic, Julie Herman, Jessica Hendricks, Evan Hill

Data

The Marsh Vulnerability Index (MVI) is a spatially-resolved assessment of Virginia tidal marsh vulnerabilities from important climate-change drivers – erosion vulnerability, inundation from sea level rise, and salinity intrusion from sea level rise – that can support management decisions. Effects were evaluated for two time-steps (near and longer-term planning horizons): 2050 and 2100.

The Marsh Vulnerability Index Applied to Coastal Shorelines layer extends the MVI evaluation for use in evaluating living shoreline (i.e., created or enhanced shoreline marshes) vulnerability and applies it to tidal shorelines in coastal Virginia. Outputs from this analysis were intended to evaluate the vulnerability of areas …

Management Practices For Urban Areas In The Hampton Roads Vicinity: Data Files, Gary F. Anderson

Data

During 1980 through 1981, the Virginia Institute of Marine Science conducted studies in the Hampton Roads Virginia vicinity to assess pollutant loading in runoff from various land use types. The 13 urban study areas also included established BMPs such as grassy swales and retention ponds to measure their effectiveness in reducing pollutant loads to the Chesapeake Bay. The focus was on nutrients, BOD and suspended solids. The studies were conducted with support of the U.S. EPA under section 208 of the Federal Clean Water Act.

Methods and results are documented in the associated publication. Data files were processed using SPSS …

Cruise: Yr071217, Stations S4408-S4420, Gloucester Point, York River Virginia 6-Hour Mudbed Calibration Survey Bracketing A Flood Tide, Grace M. Massey, Carl T. Friedrichs

Data

Dataset consists of profile and water column burst data and bottom burst data collected as part of a 6-hour anchor station survey in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Cruise: Yr150825, Stations S5534-S5540, Yorktown, York River Virginia 6-Hour Mudbed Calibration Survey Bracketing An Ebb Tide, Grace M. Massey, Carl T. Friedrichs

Data

Dataset consists of profile and water column burst data and bottom burst data collected as part of a 6-hour anchor station survey in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.

Sediment Survey: Yr060503 , Station 3908, Clay Bank, York River Virginia, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

This dataset consists of sediment properties including grain size distribution, percent moisture, percent organic matter, sediment bed erodibility, as well as (in most cases) x-ray images of the sediment structure. Most samples were taken in support of an Acoustic Doppler Velocimeter (ADV) tripod deployed in nearby location.