Physical Sciences and Mathematics Commons^™

Thermal Tuning Of Mid-Infrared Plasmonic Antenna Arrays Using A Phase Change Material, Mikhail A. Kats, Romain Blanchard, (...), M. M. Qazilbash, Et Al.

Arts & Sciences Articles

We demonstrate that the resonances of infrared plasmonic antennas can be tuned or switched on/off by taking advantage of the thermally driven insulator-to-metal phase transition in vanadium dioxide (VO2). Y-shaped antennas were fabricated on a 180 nm film of VO2 deposited on a sapphire substrate, and their resonances were shown to depend on the temperature of the VO2 film in proximity of its phase transition, in good agreement with full-wave simulations. We achieved tunability of the resonance wavelength of approximately 10% (>1 μm at λ ∼ 10 μm).

Projected Hg Dietary Exposure Of 3 Bird Species Nesting On A Contaminated Floodplain (South River, Virginia, Usa), Jc Wang, Mc Newman

VIMS Articles

Dietary Hg exposure was modeled for Carolina wren (Thryothorus ludovicianus), Eastern song sparrow (Melospiza melodia), and Eastern screech owl (Otus asio) nesting on the contaminated South River floodplain (Virginia, USA). Parameterization of Monte-Carlo models required formal expert elicitation to define bird body weight and feeding ecology characteristics because specific information was either unavailable in the published literature or too difficult to collect reliably by field survey. Mercury concentrations and weights for candidate food items were obtained directly by field survey. Simulations predicted the probability that an adult bird during breeding season would ingest specific amounts of Hg during daily foraging …

Synthesis And Fluorescence Studies Of Ph-Responsive Rhodamine B Derivatives, William Lawrence Czaplyski

Dissertations, Theses, and Masters Projects

No abstract provided.

Simulated Tsunami Inundation For A Range Of Cascadia Megathrust Earthquake Scenarios At Bandon, Oregon, Usa, Rc Witter, Yinglong J. Zhang, Kl Wang, Gr Priest, C Goldfinger

VIMS Articles

Characterizations of tsunami hazards along the Cascadia subduction zone hinge on uncertainties in megathrust rupture models used for simulating tsunami inundation. To explore these uncertainties, we constructed 15 megathrust earthquake scenarios using rupture models that supply the initial conditions for tsunami simulations at Bandon, Oregon. Tsunami inundation varies with the amount and distribution of fault slip assigned to rupture models, including models where slip is partitioned to a splay fault in the accretionary wedge and models that vary the updip limit of slip on a buried fault. Constraints on fault slip come from onshore and offshore paleoseismological evidence. We rank …

Regression Modeling Of The North East Atlantic Spring Bloom Suggests Previously Unrecognized Biological Roles For V And Mo, Nj Klein, Aj Beck, Da Hutchins, Sa Sanudo-Wilhelmy

VIMS Articles

In order to identify the biogeochemical parameters controlling pCO(2), total chlorophyll a, and dimethyl sulfide (DMS) concentrations during the North East Atlantic Spring Bloom (NASB), we used previously unpublished particulate and dissolved elemental concentrations to construct several linear regression models; first by hypothesis testing, and then with exhaustive stepwise linear regression followed by leave-one-out cross-validation. The field data was obtained along a latitudinal transect from the Azores Islands to the North Atlantic, and best-fit models (determined by lowest predictive error) of up to three variables are presented. Total chlorophyll a is predicted best by biomass (POC, PON) parameters and by …

Summary Tables: York County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Carl Hershner, Kory Angstadt, David Stanhope, David Weiss, Karen Duhring, Christine Tombleson

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Investigations Of The Life Cycle Of The Peritrich Ciliate Zoothamnium Intermedium In Chesapeake Bay, Sikai Peng

Dissertations, Theses, and Masters Projects

Epibiosis is a common phenomenon in aquatic environments. The chitinous exoskeletons of crustaceans provide stable surfaces for attachment and growth of epibiotic microorganisms. Epibiont ciliate colonization on copepods is commonly recorded but has rarely been studied in Chesapeake Bay; also, little is known about the life cycles of epibiont ciliates in the bay.

The present work focuses on the life cycle of Zoothamnium intermedium in Chesapeake Bay. A peritrich ciliate belonging to the genus Zoothamnium was found as an epibiont on the calanoid copepods Acartia tonsa and Pseudodiaptomus pelagicus during the summer in the York River, a tributary of the …

The Development Of Ecological Functions In Created Forested Wetlands, Sean P. Charles

Dissertations, Theses, and Masters Projects

Wetland mitigation has become a 2.4 billion dollar per year industry in the U.S. and in Virginia it leads to the replacement of 77 ha of palustrine forested wetlands (PFWs) per year with mitigation wetlands, including created forested wetlands (CFWs). Mitigation hinges on the idea that compensation wetlands lead to “no net loss of wetland function” when compared to impacted wetlands. We assessed the functions of provision of habitat and biogeochemical functions associated with production of biomass, the retention and removal of nutrients and the accumulation of soil C over 8 years in seven CFWs of approximately 11 and 20 …

Model Sensitivity In Holographic Superconductors And Their Deconstructed Cousins, Joshua X. Erlich, Zhen Wang

Arts & Sciences Articles

Holographic models of superconductors successfully reproduce certain experimental features of high-temperature superconductors, such as a large gap-to-Tc ratio compared to that of conventional superconductors. By deconstructing the extra dimension of these holographic models, similar phenomenology is described by a class of models defined in the natural dimension of the superconducting system. We analyze the sensitivity of certain observables in holographic and deconstructed holographic superconductors to details of the extra-dimensional spacetime. Our results support the notion that certain quantitative successes of simple models of this type are accidental. However, we also find a certain universal relationship between superconducting observables.

Atom Economical, One-Pot, Three-Reaction Cascade To Novel Tricyclic 2,4-Dihydro-1h-Benzo[F]Isochromenes, Robert J. Hinkle, Shane E. Lewis

Arts & Sciences Articles

A three-step domino reaction between 1-aryl-3-hexyne-2,6-diol derivatives and aldehydes is used to construct tricyclic 1,4-dihydro-2H-benzo[f]isochromenes. The cascade is initiated by BF₃·OEt₂ and involves alkynyl-Prins cyclization, Friedel–Crafts alkenylation, and dehydration/aromatization to create a new, central aromatic ring and eliminate 2 equiv. of water. Electron-donating substituents on the aryl ring of the 1-aryl-3-hexyne-2,6-diols significantly increase overall yields as do electron-rich aldehyde reaction partners. For 2,4-disubstituted 2H-benzo[f]isochromene products, diastereoselectivities in the alkynyl-Prins reaction are ∼1.4 : 1 in favor of the cis-diastereomer. The stereochemistry of one cis-product was verified by …

Eigenvalue Pairing In The Response Matrix For A Class Of Network Models With Circular Symmetry, Miriam Farber, Charles R. Johnson, Wei Zhen

Arts & Sciences Articles

We consider the response matrices in certain weighted networks that display a circular symmetry. It had been observed empirically that these exhibit several paired (multiplicity two) eigenvalues. Here, this pairing is explained analytically for a version of the model more general than the original. The exact number of necessarily paired eigenvalues is given in terms of the structure of the model, and the special structure of the eigenvectors is also described. Examples are provided.

Calcium Concentration Fluctuations And Subspace Volume Influence Calcium-Regulated Calcium Channel Gating And Subspace Dynamics, Seth H. Weinberg, Gregory D. Smith

Arts & Sciences Articles

No abstract provided.

A Population Density Domain Model For Calcium-Inactivation Of L-Type Calcium Channels, Kiah Hardcastle, Seth H. Weinberg, Gregory D. Smith

Arts & Sciences Articles

No abstract provided.

Summary Tables: City Of Poquoson, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Tamia Rudnicky, Carl Hershner, David Stanhope, David Weiss, Julie Bradshaw, Christine Tombleson

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Assessment Of Hypoxia And Its Relationship With Nutrient Loads And Wind, And Implication To The Chesapeake Bay Management, Ping Wang, Harry V. Wang, Lewis Linker

Reports

Statistics are applied to analyze the correlations of summer hypoxia in the Chesapeake Bay with watershed input and wind conditions based on nearly three decades of monitoring data. The Pearson correlation coefficients indicate that the averaged summer hypoxia has strong positive correlation with watershed nutrient load and discharge, and moderate negative correlation with summer average wind speed. Nutrient inputs and the subsequent decay of organic matter are the primary factor that controls the oxygen demand causing summer hypoxia, while episodic wind can partly erode stratification and hypoxia. The interannual variation of hypoxia is mainly controlled by watershed input, but wind …

Recurrent Flooding Study For Tidewater Virginia, Molly Mitchell, Carl Hershner, Julie Herman, Daniel E. Schatt, Emily Eggington, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

No abstract provided.

Gis Data: York County, Virginia Tidal Marsh Inventory, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Carl Hershner, Kory Angstadt, David Stanhope, David Weiss, Karen Duhring, Christine Tombleson

Data

The 2013 Tidal Marsh Inventory update for York County, Virginia was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.

Gis Data: Charles City County, Virginia Tidal Marsh Inventory, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Kory Angstadt, Julie Bradshaw, David Weiss, Carl H. Hershner

Data

The 2013 Tidal Marsh Inventory update for Charles City County, Virginia was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.

Gis Data: Charles City County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Kory Angstadt, Julie Bradshaw, David Weiss, Carl Hershner

Data

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions:

1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. GPS registered videography was used to collect data on conditions observed in the field.

Three GIS …

Gis Data: York County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Carl Hershner, Kory Angstadt, David Stanhope, David Weiss, Karen Duhring, Christine Tombleson

Data

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions: 1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes.

The 2009 Inventory for York County was updated using on-screen, digitizing techniques in ArcMap v10.0 while …

Application Of Acoustics And Optics For The Characterization Of Suspended Particulate Matter Within An Estuarine Observing System, Grace M. Cartwright

Dissertations, Theses, and Masters Projects

As part of this dissertation work, a long term observing station at Clay Bank on the York River in Virginia has been established and maintained since 2006, and was used to gain a better understanding of sediment processes in a muddy estuary and in muddy coastal environments in general. While data from this NSF-funded Multi-Disciplinary Benthic Exchange Dynamic (MUDBED) observing system has and will be used by other students for this general purpose, this dissertation focuses specifically on better understanding and interpretation of the data collected by key instrumentation regularly deployed at the observing station, especially the acoustic Doppler velocimeter …

Acoustic And Sedimentological Investigations Of Seabed Conditions And Related Bio-Geological Parameters In A Tidally Energetic, Fine-Grained Environment: York River Estuary, Virginia, Lindsey M. Kraatz

Dissertations, Theses, and Masters Projects

The transport and fate of fine-grained sediments is a critical factor affecting the physical, chemical, and biological health of estuaries, coastal embayments, riverine, lacustrine, and continental shelf environments. A geophysical and sedimentological study of the York River as a part of the NSF Multi-disciplinary Benthic Exchange Dynamics (MUDBED) project was conducted to determine: 1) the primary drivers of sediment erodibility within a fine-grained system, 2) if these drivers can be accurately measured through sedimentological and acoustic information, and 3) the spatial and seasonal variability of erosion within the estuary. Previous studies indicate that increased erodibility within the York River Estuary …

Electroless Gold Deposition With Self-Assembled Monolayers For Gas Chromatography Stationary Phases, Jessica Lynn Belton

Dissertations, Theses, and Masters Projects

No abstract provided.

Habitat And Fish Population Dynamics: Advancing Stock Assessments Of Highly Migratory Species, Patrick D. Lynch

Dissertations, Theses, and Masters Projects

Fisheries sustainability is inherently linked to an understanding of the population-level effects of fishing. With an accurate characterization of historical fish and fishery dynamics, management agencies are more equipped to create regulations that sustain fishery resources over the long term. The overarching goal of this dissertation is to contribute to the advancement of fisheries stock assessment and promote resource sustainability. My research focused on highly migratory species (HMS), particularly fishes that reside in the open ocean. These species constitute some of the highest valued global fisheries; however, numerous factors compromise HMS stock assessment and management. These challenges are fully described …

Surface Modifications For Gas Chromatography Micro Columns, Daniel Andre Hirtenstein

Dissertations, Theses, and Masters Projects

No abstract provided.

Distribution And Impacts Of Invasive Bivalve Corbicula Fluminea In Tidal Freshwater York River Tributaries, Matthew Ryan Freedman

Dissertations, Theses, and Masters Projects

The Asian clam, Corbicula fluminea, is one of the most invasive bivalves in the world but there is limited research on its presence in tidal freshwater systems. Despite its introduction into Chesapeake Bay tributaries in the 1970s, the initial colonization and subsequent development of populations of C. fluminea in the Mattaponi and Pamunkey sub-tributaries of the York River, Virginia, is mostly undocumented. This study assessed the spatial distribution and population structure of C. fluminea in tidal freshwater sections of these rivers (~45km) with benthic surveys during summer 2011 – 2012. Benthic grabs (2.4L, 0.023m2) taken at 40 sites in each …

Optical Characterization Of Magnetism In Magnetic/Nonmagnetic Heterostructures, Yichun Fan

Dissertations, Theses, and Masters Projects

This thesis focuses on the study of the static and dynamic magnetic interactions in ferromagnetic/nonmagnetic heterostructures using interface-specific and time-resolved optical techniques. The goal of this thesis is to elucidate the interface exchange coupling, magnetic anisotropy, and coherent spin dynamics in these advanced material systems, crucial to the realization of high performance spintronic devices.;First, a pronounced exchange bias (EB) phenomenon is observed in Fe/MgO (001) by magnetic second harmonic generation. The bulk magnetization does not, in marked contrast to typical systems where EB is manifested only in the net magnetization. The magnitude of the exchange bias varies with interface oxygen …

Multi-Meson Systems From Lattice Quantum Chromodynamics, Zhifeng Shi

Dissertations, Theses, and Masters Projects

Systems of non-zero isospin chemical potential ( muI), where the chemical potential for up and down quarks is equal in magnitude but of opposite sign, do not suffer from the sign problem, and normal LQCD techniques can be successfully adapted to study such systems. From chiral perturbation theory (chiPT), in addition to the deconfined phase transition at high temperature at zero chemical potential, another phase transition from ordinary hadronic states to a Bose Einstein Condensate (BEC) state has been conjectured [1] at non-zero isospin chemical potential. Such a BEC phase is of phenomenological relevance in the interior of neutron stars.;In …

Applications Of Holographic Dualities, Dylan Judd Albrecht

Dissertations, Theses, and Masters Projects

We introduce and review some of the building blocks to what is known as the AdS/CFT correspondence. We then present, using the framework of the correspondence, two applications: one to QCD (Chapters 2 and 3) and one to superconductivity (Chapter 4). The work presented in these chapters was carried out by the author and collaborators during the author's graduate studies.

Improving Security And Privacy In Online Social Networks, Wei Wei

Dissertations, Theses, and Masters Projects

Online social networks (OSNs) have gained soaring popularity and are among the most popular sites on the Web. With OSNs, users around the world establish and strengthen connections by sharing thoughts, activities, photos, locations, and other personal information. However, the immense popularity of OSNs also raises significant security and privacy concerns. Storing millions of users' private information and their social connections, OSNs are susceptible to becoming the target of various attacks. In addition, user privacy will be compromised if the private data collected by OSNs are abused, inadvertently leaked, or under the control of adversaries. as a result, the tension …