Physical Sciences and Mathematics Commons^™

Public Beach Assessment Report Gloucester Point Public Beach, Gloucester County, Virginia, Donna A. Milligan, C. Scott Hardaway Jr., George R. Thomas

Reports

Gloucester Point Public Beach is located at the southern end of Gloucester County, Virginia on the York River. It is a southeastward facing shoreline about 960 ft long and it is part of a larger stretch of moderately low shore between Sarah Creek and the George P. Coleman Bridge. While no shoreline improvement projects have taken place at the public beach, shore protection projects updrift and including the Virginia Institute of Marine Science (VIMS) affect it. In 1983, erosion along the shoreline at VIMS just updrift of the public beach led to the installation of a riprap revetment in front …

Public Beach Assessment Report Yorktown Public Beach, Yorktown, Virginia, Donna A. Milligan, C. Scott Hardaway Jr., George R. Thomas

Reports

No abstract provided.

Distribution Of Submerged Aquatic Vegetation In The Chesapeake Bay And Tributaries And Chincoteague Bay - 1995, Robert J. Orth, Judith F. Nowak, Gary F. Anderson, David J. Wilcox, Jennifer R. Whiting, Leah S. Nagy

Reports

No abstract provided.

Yellow Sea & East China Sea Bibliography, Nicole D. Scott, Patricia T. Carrier, John D. Milliman

Reports

No abstract provided.

The Virginia Wetlands Report Vol. 11, No. 3, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Great Blue Heron. Julie G. Bradshaw
• Weakfish. Lyle Varnell
• Geographic Information Systems Support Tributary Strategy Planning in Virginia. Marcia Berman
• Wetlands and Regional Watershed Management. Katie Hopkins
• Cranberries. Pam Mason
• What is a groin and how does it work? William Roberts

Detritus: Mother Nature's Rice Cake, Pamela Mason, Lyle M. Varnell, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Semiclassical Scattering In A Circular Semiconductor Microstructure, C. D. Schwieters, J. A. Alford, John B. Delos

Arts & Sciences Articles

The conductance of a microscopic junction shows fluctuations caused by quantum interference of waves that follow different paths between the leads. We give a semiclassical formula for these fluctuations. The theory utilizes trajectories which travel between the centers of the lead apertures; it also incorporates diffraction at these apertures. We extend the theory to include ‘‘ghost paths,’’ which scatter diffractively off the lead mouths. Semiclassical S-matrix elements are computed for a circular junction over a range of Fermi wave numbers, and the large-scale structure of these matrix elements shows good agreement with quantum results. Finally, we propose a hypothesis …

Slow Down, D. Chris Benner, Rodelle A. Benner

Arts & Sciences Articles

No abstract provided.

Computational Algebra Applications In Reliability, G Hartless, Lawrence Leemis

Arts & Sciences Articles

Reliability analysts are typically forced to choose between using an 'algorithmic programming language' or a 'reliability package' for analyzing their models and lifetime data. This paper shows that computational languages can be used to bridge the gap to combine the flexibility of a programming language with the ease of use of a package. Computational languages facilitate the development of new statistical techniques and are excellent teaching tools. This paper considers three diverse reliability problems that are handled easily with a computational algebra language: system reliability bounds; lifetime data analysis; and model selection.

Methods Of Risk Analysis: Traditional And Ecological Approaches, John Buie, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Research Needs For The Risk Assessment Of Health And Environmental Effects Of Endocrine Disruptors: A Report Of The Us Epa-Sponsored Workshop, Rj Kavlock, Gp Daston, C Derosa, P Fennercrisp, Le Gray, S Kaattari, Et Al

VIMS Articles

The hypothesis has been put forward that humans and wildlife species have suffered adverse health effects after exposure to endocrine-disrupting chemicals. Reported adverse effects include declines in populations, increases in cancers, and reduced reproductive function. The U.S. Environmental Protection Agency sponsored a workshop in April 1995 to bring together interested parties in an effort to identify research gaps related to this hypothesis and to establish priorities for future research activities. Approximately 90 invited participants were organized into work groups developed around the principal reported health effects-carcinogenesis, reproductive toxicity, neurotoxicity, and immunotoxicity--as well as along the risk assessment paradigm--hazard identification, dose-response …

Bifurcation Of The Periodic Orbits Of Hamiltonian Systems: An Analysis Using Normal Form Theory, D. A. Sadovskii, John B. Delos

Arts & Sciences Articles

We develop an analytic technique to study the dynamics in the neighborhood of a periodic trajectory of a Hamiltonian system. The theory begins with Poincaré and Birkhoff; major modern contributions are due to Meyer, Arnol'd, and Deprit. The realization of the method relies on local Fourier-Taylor series expansions with numerically obtained coefficients. The procedure and machinery are presented in detail on the example of the ‘‘perpendicular’’ (z=0) periodic trajectory of the diamagnetic Kepler problem. This simple one-parameter problem well exhibits the power of our technique. Thus, we obtain a precise analytic description of bifurcations observed by J.-M. Mao …

Advances In Wetland Status And Trends Monitoring Cumulative Error Comparisons, Stacie A.C. Nelson, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Restoration And Creation Of Forested Wetlands: A Guide, Cathy Palmintier, Bonny Lee Appleton, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

The Virginia Wetlands Report Vol. 11, No. 2, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Northern Harrier, or Marsh Hawk. Julie G. Bradshaw
• Bay Anchovy. Lyle Varnell
• Geographic Information System (GIS) Data Exchange- The State of the Problem, Part 2. Marcia Berman
• General Assembly Passes, and Governor Signs Wetlands Mitigation Banking Legislation.
• Second Edition of the Virginia Wetlands Management Handbook Now Available.
• Wetlands Management Symposium: Wetlands Compensation Survey Results
• Westmoreland State Park. Pam Mason
• Literally, what is littoral sand movement? William Roberts

Plant Adaptations To Saturated Soils And The Formation Of Hypertrophied Lenticels And Adventitious Roots In Woody Species, Kirk J. Havens, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

1996 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Effects Of Channel Geometry On Cross Sectional Variation In Along Channel Velocity In Partially Stratified Estuaries, Carl T. Friedrichs, John M. Hamrick

VIMS Books and Book Chapters

Analytic solutions for along‐channel velocity through an estuarine cross‐section with laterally varying depth are compared to observations from an array of current meters deployed over a nearly triangular cross‐section of the James River estuary. Analytic results suggest that the transverse structure of along‐channel velocity at this cross‐section is primarily due to simple density‐driven circulation modified by bathymetry. Comparisons of analytic solutions for the amplitude and phase of tidal velocity to observations suggest that linear models which include realistic lateral depth variation should also incorporate across‐channel variation in eddy viscosity. Solutions for various contributions to mean velocity are then derived which …

The Virginia Wetlands Report Vol. 11, No. 1, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Black Skimmer. Julie G. Bradshaw
• Alewife. Lyle Varnell
• Geographic Information System (GIS) Data Exchange- The State of the Problem. Marcia Berman
• Northern Neck Workshops Prove Profitable to Participants. Beth Peacock
• Grazing and Haying Activities in Wetlands. Pamela Mason
• Should I fertilize my tidal marsh? William Roberts

Radical Environmentalism And Religion, Evelyn Louise Bush

Dissertations, Theses, and Masters Projects

No abstract provided.

1996 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Structured Eigenvectors, Interlacing, And Matrix Completions, Brenda K. Kroschel

Dissertations, Theses, and Masters Projects

This dissertation presents results from three areas of applicable matrix analysis: structured eigenvectors, interlacing, and matrix completion problems. Although these are distinct topics, the structured eigenvector results provide connections.;It is a straightforward matrix calculation that if {dollar}\lambda{dollar} is an eigenvalue of A, x an associated structured eigenvector and {dollar}\alpha{dollar} the set of positions in which x has nonzero entries, then {dollar}\lambda{dollar} is also an eigenvalue of the submatrix of A that lies in the rows and columns indexed by {dollar}\alpha{dollar}. We present a converse to this statement and apply the results to interlacing and to matrix completion problems. Several corollaries …

Effects Of Periodic Environmental Hypoxia On Predator Utilization Of Macrobenthic Infauna, Janet A. Nestlerode

Dissertations, Theses, and Masters Projects

Hypoxia and anoxia have significant deleterious ecological effects on living resources throughout many estuarine and marine ecosystems worldwide. Brief periods of low oxygen facilitate transfer of benthic production to higher trophic levels as many benthic infaunal species have shallower sediment depth distributions during hypoxic events. A baited time-lapse camera equipped with a water quality datalogger was used to document in situ exploitation of oxygen-stressed benthic invertebrate prey organisms by mobile fish and crustacean predators during alternating normoxia-hypoxia cycles in the York River. Based on photographic and diver observations, this hypoxiainduced benthic-pelagic transfer of production is more likely to occur when …

Virginia Game Fish Tagging Program Annual Report 1995, Cm Bain Iii, John A. Lucy

Reports

The Virginia Came Fish tagging Program (VGFTP) was established in 1995 as an ongoing, cooperative project of the Virginia Marine Resources Commission and the Virginia Institute of Marine Science of the College of William and Mary The project is funded with revenues generated by Virginia's marine recreational fishing license.

Temporal Variablity Of The Pycnocline In The Mid-Chesapeake Bay, Linda Jane Frizzell-Makowski

Dissertations, Theses, and Masters Projects

Mixing and dispersion in a partially mixed estuary are driven by, among other processes, the gravitational circulation, wind-events and tides. These processes are important in the vertical and horizontal distribution and exchange of salinity, oxygen, nutrients, and organisms. The objective of this research was to examine the temporal variability of the pycnocline in the mid-Chesapeake Bay in response to forcing at subtidal and higher frequencies as observed in the spring of 1993. The largest change in the pycnocline was associated with meteorological forcing. Up-Bay wind stress and subsequent abatement of the wind stress produced a 5 meter displacement of the …

The Role Of Epibenthic Predators In Structuring Marine Soft-Bottom Communities Along An Estuarine Gradient, Rochelle D. Seitz

Dissertations, Theses, and Masters Projects

A unifying theory of community regulation in soft-bottom systems remains elusive, despite extensive field studies on factors controlling community structure. Here, I have (1) reviewed models of community regulation, (2) examined the role of predation in controlling benthic diversity along a salinity gradient, (3) examined effects of predation upon an abundant bivalve, Macoma balthica, and (4) revised a model of community regulation in an estuarine soft-bottom system. The Menge and Sutherland (MS) "consumer stress model" posits that consumers feed ineffectively in harsh environments, and the importance of physical disturbance, competition and predation varies with recruitment, environmental conditions, and trophic position. …

Water Quality Modeling As An Inverse Problem, Jian Shen

Dissertations, Theses, and Masters Projects

An inverse mathematical estuarine eutrophication model has been developed. The model provides a framework to estimate unknown parameters by assimilation of the concentration data of those state variables. The inverse model developed is a laterally integrated, two-dimensional, real-time model which consists of a hydrodynamic model, an eutrophication model and an adjoint model. The hydrodynamic model provides the dynamic fields for both the eutrophication model and the adjoint model. The eutrophication model simulates eight water quality state variables which are phytoplankton, organic nitrogen, ammonium nitrogen, nitrite-nitrate nitrogen, organic phosphorus, inorganic (ortho) phosphorus, carbonaceous biochemical oxygen demand and dissolved oxygen. The adjoint …

Field And Laboratory Evidence Of Pheromone Mediated Mating Behavior In The Blue Crab, Callinectes Sapidus, Donald S. Gibbs

Dissertations, Theses, and Masters Projects

No abstract provided.

Synthesis And Characterization Of Cyclic Arylene Ether Oligomers, David Lewis Eldridge

Dissertations, Theses, and Masters Projects

No abstract provided.

Synthesis And Characterization Of Boron-Containing Polymeric Materials For Neutron Shielding Applications, Michael B. Glasgow

Dissertations, Theses, and Masters Projects

The development of boron-containing polymeric materials for neutron shielding applications was undertaken. Three types of materials were characterized for physical and thermal properties: boron powder-filled epoxy composites, carborane polyamides having boron chemically bonded into the polymer, and boron-loaded polyimide thin films. Addition of amorphous submicron boron powder did not affect significantly the thermal performance of the epoxy. The 17% boron loading produced a 26% increase in compressive failure strength and a 68% increase in the compressive modulus. 0.125 inch thick specimens containing 17% boron absorbed 92% of incident neutrons from a 5-Curie Pu/Be source compared with {dollar}<{dollar}1% for the neat epoxy. Dispersion of the boron in the epoxy was improved with the addition of larger size crystalline boron powders. Carborane polyamides containing up to 35% boron were thermally stable up to 400{dollar}\sp\circ{dollar}C in air. The polymers had hydrogen/boron ratios from 2.0 to 3.8 and were soluble in several organic solvents. Polymer solutions were processed into clear, colored thin films. Boron-filled polyamic acid solutions of a PMDA-ODA polyimide containing up to 10% boron were processed into thin films. Neutron absorption of the opaque films measured in a 5-Curie Pu/Be neutron source was linear with boron concentration and film thickness. The fraction of neutrons absorbed varied linearly with boron concentration and film thickness. The applicability of boron-containing materials to the aerospace, nuclear power and accelerator industries was investigated.