Shore Erosion at Tangier Island

Tangier Island, in Accomack County, Virginia, is the southernmost of a series of islands separating Chesapeake Bay from Tangier and Pocomoke Sounds (Figure 1) . With the exception of three sand ridges, which are the populated areas, the island is low lying marsh and tidal flat deposits with elevations generally below 6 feet (MLW datum)

Baltimore Harbor and channels : surface sediments in Virginia channels

Bottom surface sediment samples in the Virginia Channels portion of the Baltimore Harbor and Channels Project and the four specified disposal sites were obtained and chemically analysed in accordance with DAC W31-78-C-0038. In addition, chemical analyses were performed on 15 sediment samples delivered to us from Maryland. In total, 90 stations were occupied in Virginia Channels and the four proposed disposal sites for bottom surface sediments for bulk chemical analyses. Samples from the Maryland Channels were supplied by the Maryland Geological Survey.

Physico-chemical properties of ionic-liquid water mixtures

In order for Ionic Liquids (ILs) to be utilized to their full potential, it is necessary to have a complete understanding of their physical properties, including phase transitions temperatures1. We have previously reported into the extent of structuring of ILs using photochromic molecular probes, and investigated the appropriate IL water content to yield hydrated IL systems for analysis of polarity and to create environments suitable for effective enzyme activity 1,2,3. In this study we investigated interactions in hydrated ILs containing variable hydrophobic and hydrophilic regions through optical and thermal analysis. The enthalpies and phase transitions of the systems were compared, between the temperature range -50°C to +30°C for the ILs with varying degrees of hydration. Reichardtʼs dye was used as a molecular probe to monitor changes in interactions in the ILs as a function of temperature. Comparisons were made between ILs and for ILs with varying degrees of hydration. Spectroscopic studies were performed using Perkin Elmer UV-Visible Spectrometer and phase transitions monitored using a Perkin Elmer Differential Scanning Calorimeter. The ILs examined are; Trihexyltetradecylphosphonium Chloride [P6,6,6,14 Cl] Tributyl-tetradecylphosphonium Chloride, [P4,4,4,14 Cl], 1-Ethyl-methyl-3-imidazolium-ethyl Sulfate [Emim][EtSO4] and Trihexyltetradecylphosphonium Dicyanamide [P6,6,6,14 DCA]. 1. Robert Byrne, Simon Coleman, Simon Gallagher, and Dermot Diamond. Designer Molecular Probes for Phosphonium Ionic Liquids. Physical Chemistry Chemical Physics, 2010. 2. Kyoko Fujita, Douglas R. MacFarlane, Maria Forsyth, Masahiro Yoshizawa-Fujita, Kenichi Murata,† Nobuhumi Nakamura, and Hiroyuki Ohno*,Solubility and Stability of Cytochrome c in Hydrated Ionic Liquids: Effect of Oxo Acid Residues and Kosmotropicity, 2007. 3. SergeiV.DzyubaandRichardA.Bartsch,Expandingthepolarityrange of ionic liquids, Tetrehedron Letters, 2002

On basin hyposmetry and the morphodynamic response of coastal inlet systems

The exchange of water and entrained material between coastal basins and the inner continental shelf reduces to the problem of polarized transport (flood +, ebb —) in the conveyance channels routing flow through a coastal inlet. Here the net long-term movement of materials is largely a function of the fluid velocity and discharge — variables whose time history at-a-station contains both periodic and aperiodic elements. In this paper the importance of the major periodic elements in coastal inlet flows and their potential contribution to the net transport of bedload materials is discussed

Dredging and Disposal in the Chesapeake Bay

The management questions involved in dredging and open water dredged material disposal revolve around three basic issues: 1) stability of the dredged material within the defined disposal area, 2) altered resource value of bottoms affected by dredged material, and 3) mobilization of toxins from contaminated dredged material. These issues encompass all aspects of the physical and biological character of a project site. The actual evaluation of dredging and dredged material disposal has generally concentrated on acute impacts to bottom dwelling organisms, benthos, and or to water column characteristics. This emphasis has resulted in ample evidence that many disposal practices have at least short term detrimental effects. With few exceptions, these studies have failed to assess the relationships between the benthos and the dredged material as a new sediment habitat, or the consequences of altering the hydrodynamic regime, or the resource value of the benthos.https://scholarworks.wm.edu/vimsbooks/1156/thumbnail.jp

Baltimore Harbor and channels aquatic benthos investigations : final technical report

This report describes work performed by the Virginia Institute of Marine Science, School of Marine Science of the College of William and Mary, Gloucester Point, VA, to document the existing preoperational conditions at four locations in the Chesapeake Bay selected as possible dredged material disposal areas for the deepening of the Baltimore Channel. The work was sponsored by the Baltimore District Corps of Engineers. The objectives of this work were at each of the four potential disposal sites: 1 -document the surface (0-15 em) sediment conditions spatially and temporally 2 - document macrobenthic communities spatially and temporally. 3 - empty the REMOTS sediment profile camera to document visible vertical sediment structure

Photo- and solvatochromic properties of nitrobenzospiropyran in ionic liquids containing the [NTf2]- anion

The photo-, thermo- and solvatochromic properties of 2,3-dihydro-10,30,30-trimethyl-6-nitrospiro- [1-benzopyran-2,20-1H-indole] (BSP-NO2) were studied in ILs containing the anion [NTf2]- by UV-Vis absorption spectroscopy, ab initio molecular orbital theory and density functional theory (DFT) calculations. It was found that the kinetics and thermodynamics of the BSP-NO2 MC (merocyanine) equilibrium was sensitive to the nature of the cation. It was also observed that the imidazolium cation can form a through-space orbital interaction with the MC isomer, rather than a simple electrostatic interaction, thus preventing the MC conversion back to the BSP-NO2 isomer. The BSP-NO2 MC equilibrium thus serves as a model system for studying modes of interaction of the cations in ionic liquids