Physical Sciences and Mathematics Commons^™

Crab Larval Abundance And Settlement Patterns In A Changing Chesapeake Bay, Itchika Sivaipram

Dissertations, Theses, and Masters Projects

All estuarine crabs have two larval stages, the zoea and the megalopa. Zoeae are entirely planktonic, whereas megalopae begin as plankton before beginning to search for settlement substrates as late stage megalopae. At both stages, crab larvae are subject to environmental conditions of the estuary. With changing environmental conditions due to anthropogenic activities and climate change, an understanding of how these planktonic larvae respond to environmental conditions is necessary for understanding subsequent larval supply to benthic populations and implication for fisheries management and habitat restoration. For this dissertation, I: 1) analyzed long-term timeseries in the lower Chesapeake Bay for spatial …

Radiation Shielding Bricks For Mars Using Martian Regolith Simulant And Hydrogen-Rich Polymers, Sara Sargent

Dissertations, Theses, and Masters Projects

Radiation shielding materials are an essential component of long-term space travel and habitation. The mission to Mars will require a radiation shielding material that can be produced on Mars through energy and cost-efficient means. in this study, Martian regolith simulant and hydrogen-rich polymers are used to create a radiation shielding material in the form of bricks. The bricks are capable of shielding against galactic cosmic radiation on Mars. There are three methods in which the bricks were formed: 1) a heated press, 2) a microwave oven in a CO2 atmosphere, and 3) a vacuum oven with a low CO2 pressure. …

Developing Efficient High-Order Transport Schemes For Cross-Scale Coupled Estuary-Ocean Modeling, Fei Ye

Dissertations, Theses, and Masters Projects

Geophysical fluid dynamics (GFD) models have progressed greatly in simulating the world’s oceans and estuaries in the past three decades, thanks to the development of novel numerical algorithms and the advent of massively parallel high-performance computing platforms. Study of inter-related processes on multi-scales (e.g., between large-scale (remote) processes and small-scale (local) processes) has always been an important theme for GFD modeling. For this purpose, models based on unstructured-grid (UG) have shown great potential because of their superior abilities in enabling multi-resolution and in fitting geometry and boundary. Despite UG models’ successful applications on coastal systems, significant obstacles still exist that …

Impacts Of Atmospheric Nitrogen Deposition And Coastal Nitrogen Fluxes On Chesapeake Bay Hypoxia, Fei Da

Dissertations, Theses, and Masters Projects

Although rivers are the primary source of dissolved inorganic nitrogen (DIN) inputs to the Chesapeake Bay, direct atmospheric DIN deposition and DIN fluxes from the continental shelf can also significantly impact Chesapeake Bay hypoxia. The relative role of these additional sources of DIN has not previously been thoroughly quantified. In this study, the three-dimensional Estuarine-Carbon-Biogeochemistry model embedded in the Regional Ocean Modeling System (ChesROMS-ECB) is used to examine the relative impact of these three DIN sources. Model simulations highlight that DIN inputs from the atmosphere have roughly the same impact on hypoxia as the same gram for gram change in …

Enhancing Usability, Security, And Performance In Mobile Computing, Shanhe Yi

Dissertations, Theses, and Masters Projects

We have witnessed the prevalence of smart devices in every aspect of human life. However, the ever-growing smart devices present significant challenges in terms of usability, security, and performance. First, we need to design new interfaces to improve the device usability which has been neglected during the rapid shift from hand-held mobile devices to wearables. Second, we need to protect smart devices with abundant private data against unauthorized users. Last, new applications with compute-intensive tasks demand the integration of emerging mobile backend infrastructure. This dissertation focuses on addressing these challenges. First, we present GlassGesture, a system that improves the usability …

First Measurements Of The Parity-Violating And Beam-Normal Single-Spin Asymmetries In Elastic Electron-Aluminum Scattering, Kurtis David Bartlett

Dissertations, Theses, and Masters Projects

The Qweak collaboration has made the first measurements of the elastic parity-violating and beam-normal single-spin asymmetries from the 27Al nucleus. Both are the result of ancillary measurements conducted during the Qweak experiment at Jefferson Lab. The goal of the experimental was to determine the proton's weak charge, Qp W, via a measurement of the elastic parity-violating electron-proton scattering asymmetry. During the experiment, ancillary measurements were made with different beam configurations on a separate aluminum alloy target, in an effort to directly measure the aluminum background coming from the experiment's liquid hydrogen target cell.

This dissertation discusses three primary results: the …

Applications Of Lattice Qcd To Hadronic Cp Violation, David Brantley

Dissertations, Theses, and Masters Projects

Experimental tests of the Standard Model are reaching a precision in which they are probing beyond Standard Model parameter spaces. Increasingly precise experimental tests of the Standard Model (SM) require a concurrent theoretical push to provide ever more precise predictions to interpret experimental results. For example, future direct dark matter detection experiments, searches for Majorana neutrinos, and neutron electric dipole moment searches, all require a fundamental understanding of nuclear physics in the low-energy regime. Nuclear physics emerges from non-perturbative dynamics of the fundamental theory of the strong interaction, QCD, at low energies. Lattice QCD is currently our only systematically controllable …

Lattice Qcd For Neutrinoless Double Beta Decay: Short Range Operator Contributions, Henry Jose Monge Camacho

Dissertations, Theses, and Masters Projects

The Standard Model (SM), the fundamental theory of particle physics, very success- fully describes the world around us, and with a only a few tantalizing exceptions, all the experiments we have performed to understand the fundamental laws of nature. However, the SM accounts for only 4-5% of the matter and energy in the universe, with approxi- mately 25% composed of dark matter (DM) and the remaining 70% composed of the more mysterious dark energy. Further, the SM content of the universe is composed of an excess of matter over anti-matter of about 1 part per billion. Despite being a small …

Charge Dynamics In The Metallic And Superconducting States Of The Electron-Doped 122-Type Iron Arsenides, Zhen Xing

Dissertations, Theses, and Masters Projects

Understanding charge dynamics and the origin of superconductivity in iron-based materials is one of the most important topics in condensed matter physics. Among different structures of iron-based materials, 122-type iron arsenides are of considerable interest due to their diverse phase diagrams, relatively high superconducting transition temperatures, and the availability of high quality single crystals. In this dissertation, we study temperature and frequency dependence of charge dynamics of the electron-doped 122-type iron arsenides in the metallic and superconducting states using broadband infrared spectroscopy at cryogenic temperatures. We have investigated the charge dynamics and the nature of many-body interactions in metallic La- …

Automating Software Development For Mobile Computing Platforms, Kevin Patrick Moran

Dissertations, Theses, and Masters Projects

Mobile devices such as smartphones and tablets have become ubiquitous in today's computing landscape. These devices have ushered in entirely new populations of users, and mobile operating systems are now outpacing more traditional "desktop" systems in terms of market share. The applications that run on these mobile devices (often referred to as "apps") have become a primary means of computing for millions of users and, as such, have garnered immense developer interest. These apps allow for unique, personal software experiences through touch-based UIs and a complex assortment of sensors. However, designing and implementing high quality mobile apps can be a …

The Development And Proliferation Of Summer Algal Blooms In The Oligo/Poly-Haline Portion Of The Chesapeake Bay - Observational And Numerical Modeling Studies, Zhengui Wang

Dissertations, Theses, and Masters Projects

Algal blooms occur annually in many parts of the Chesapeake Bay. The causes of algal blooms are complex and can be different in different regions. In this study, we will conduct data analysis for the observed data and adopt various methods to investigate algal bloom phenomenon in three separate regions in the oligo/poly-haline portion of the Bay. Chapter 1 provides a general introduction of the algal bloom research in the Chesapeake Bay. In Chapter 2, an observational analysis and a numerical study on the algal blooms in Back River were conducted. A hypothesis was made that high pH can trigger …