Physical Sciences and Mathematics Commons^™

Formation And Desorption Of Negative Ions From Metal Surfaces, Douglas Hugh Baker

Dissertations, Theses, and Masters Projects

Investigations of negative ion and electron emission from gas-covered metal surfaces due to the impact of low energy (30-300 eV) positive ions and, separately, photons (2-5 eV) are presented. In both cases, the negative ion formation process is thought to occur via electron tunneling from the surface or its substrate to a sputtered or photodesorbed neutral atom or molecule.;In particular, absolute total negative ion and electron yields for collisions of positive alkali ions with a gas-covered Mo substrate have been measured. Mass analysis of the sputtered negative ions show that O{dollar}\sb2\sp-{dollar} is the dominant ion at low impact energies. This …

Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr

Dissertations, Theses, and Masters Projects

In this dissertation, I experimentally examine predation-induced mortality upon juvenile queen conch, Strombus gigas, and assess the importance of select habitat predator and conch characteristics affecting predation intensity. Experiments were conducted during the summer and early fall of 1987, 1988, 1990 and 1991 in seagrass beds and adjacent sand flats near Lee Stocking Island, Exuma Cays, Bahamas. These experiments indicate that various factors act interactively to produce habitat-specific mortality rates in queen conch due to predation. These include (1) habitat type, whereby seagrass beds offer some protection; (2) local population dynamics, such that populated seagrass beds appear to enhance conch …

Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo

Dissertations, Theses, and Masters Projects

A model of zinc accumulation by the American oyster, Crassostrea virginica, is developed by relating in-situ zinc body burden to time-integration of uptake. Short-term uptake rates are estimated in laboratory by introducing &\sp{lcub}65{rcub}&Zn to oysters of various weights in aquaria with salinities of 18&\perthous& and 12&\perthous&. Uptake of &\sp{lcub}65{rcub}&Zn by an oyster: (1) varies as a power function of the body weight (soft tissue dry weight) of the oyster (&dy\over{lcub}dt{rcub}& = kW&\sp{lcub}\beta{rcub}&), (2) is inversely related to the salinity of ambient water, and (3) increases linearly with ambient concentration. Zinc body burdens of oysters of various weights from oyster beds …

Sediment Inventory And Characterization Summary For The Desk-Top Information System (Compas), Maynard M. Nichols, Caroline Brouwer-Riel, Et Al

Reports

In this report sediment maps are compiled together with basic data on the morphology and hydrology as well as sediment sources, pathways and sinks for 21 estuarine systems In the Virginia Province (Figure 1). Additionally, It provides a processoriented characterization summary. Supportive details, documentation and references are provided In companion characterization reports.

The Effect Of A One-Meter Sea-Level Rise On Tidal Wetlands In Gloucester County, Virginia, Paula Lindsey Hill

Dissertations, Theses, and Masters Projects

No abstract provided.

An Investigation Of The Late Pleistocene Paleochannel Systems In The Continental Shelf, South Of Chesapeake Bay Mouth, Ziqiang Chen

Dissertations, Theses, and Masters Projects

No abstract provided.

Intentional Introductions Of Non-Indigenous Species: A Case Study Of Policy And Management Affecting Crassostrea Gigas, Gwynne D. Brown

Dissertations, Theses, and Masters Projects

No abstract provided.

Taxonomy Of Larval Blennioidei Of Belize, Central America, Martin Ray Cavalluzzi

Dissertations, Theses, and Masters Projects

No abstract provided.

Juvenile Pelagic Fish Communities In The Mattaponi And Pamunkey Rivers, Virginia, Steffany Dawson

Dissertations, Theses, and Masters Projects

No abstract provided.

Quasilinear Theory Of Laser-Plasma Interactions, Alastair John Neil

Dissertations, Theses, and Masters Projects

The interaction of a high intensity laser beam with a plasma is generally susceptible to the filamentation instability due to nonuniformities in the laser profile. In ponderomotive filamentation high intensity spots in the beam expell plasma by ponderomotive force, lowering the local density, causing even more light to be focused into the already high intensity region. The result--the beam is broken up into a filamentary structure.;Several optical smoothing techniques have been proposed to eliminate this problem. In the Random Phase Plates (RPS) approach, the beam is split into a very fine scale, time-stationary interference pattern. The irregularities in this pattern …

Design And Analysis Techniques For Concurrent Blackboard Systems, John William Mcmanus

Dissertations, Theses, and Masters Projects

Blackboard systems are a natural progression of Artificial Intelligence based systems into a more powerful problem solving technique. They provide a way for several highly specialized knowledge sources to cooperate to solve large, complex problems. Blackboard systems incorporate the concepts developed by rule-based and expert systems programmers and include the ability to add conventionally coded knowledge sources. The small and specialized knowledge sources are easier to develop and test, and are hosted on hardware specifically suited to the task that they are solving.;Designing and developing blackboard systems is a difficult process. The designer is attempting to balance several conflicting goals …

Painleve Singularity Analysis Applied To Charged Particle Dynamics During Reconnection, Jay Walter Larson

Dissertations, Theses, and Masters Projects

For a plasma in the collisionless regime, test-particle modelling can lend some insight into the macroscopic behavior of the plasma, e.g conductivity and heating. A common example for which this technique is used is a system with electric and magnetic fields given by B = {dollar}\delta y{dollar}cx x + xcx y + {dollar}\gamma{dollar}cx z and E = {dollar}\epsilon{dollar}cx z, where {dollar}\delta{dollar}, {dollar}\gamma{dollar}, and {dollar}\epsilon{dollar} are constant parameters. This model can be used to model plasma behavior near neutral lines, ({dollar}\gamma{dollar} = 0), as well as current sheets ({dollar}\gamma{dollar} = 0, {dollar}\delta{dollar} = 0). The integrability properties of the particle motion …

Synthesis And Inclusion Of 1-(5-Cyanonaphthyl) Diazomethane With B-Cyclodextrin, Scott Tobias Forrest

Dissertations, Theses, and Masters Projects

No abstract provided.

Verification Of Fault-Tolerant Clock Synchronization Systems, Paul S. Miner

Dissertations, Theses, and Masters Projects

No abstract provided.

A Helium Discharge Detector For The Determination Of Organosulfur And Phosphorus Compounds, Tamara L. Tieman

Dissertations, Theses, and Masters Projects

No abstract provided.

The Imidization Reactions Of Pmr-15 Polyimide, Kerri Ann Robillard

Dissertations, Theses, and Masters Projects

No abstract provided.

Oyster Spatfall In Virginia Waters: 1991 Annual Summary, Bruce J. Barber

Reports

The Virginia Institute of Marine Science (VIMS) conducts surveys of oyster spatfall (or "setting") in Virginia waters throughout the summer reproductive period. This survey provides an estimate of the potential of a particular area for receiving a "strike" or set of oysters on the bottom and helps define the timing of setting events. Information obtained from this effort is valuable to the Virginia Marine Resources Commission (VMRC) for its shell repletion program, and to private oyster growers, both of which are interested in maximizing the timing of shell planting. In addition, by maintaining a long-term data base, trends in spatfall …

Sediment Characterization Of Coastal Lagoons And Bays, Mid-Atlantic Region, Maynard N. Nichols, C. M. Brouwer-Riel

Reports

Sediment characterizations for the following lagoons and bays:

• Great South Bay
• Barnegat Bay
• New Jersey Inland Bays, Great Sound
• Delaware Inland Bays
• Chincoteague Bay

Sediment Characterization Of Chesaapeake Bay And Its Tributaries, Maynard M. Nichols, S. C. Kim, C. M. Brouwer

Reports

Sediment characterizations for the following estuaries and rivers:

• Chesapeake Bay
• Potomac River
• Rappahannock River
• York River
• James River
• Chester River
• Choptank River

Water Quality In Chesapeake Bay : Virginia Portion, Water Year 1990 : A Report To The Virginia Water Control Board, Kevin Curling, Bruce Neilson

Reports

The purpose of this report is to characterize water quality conditions during the 1990 water year, October 1989 through September 1990. For the most part, the information is provided in graphical format. Only data for the Virginia portion of Chesapeake Bay is included. No data analysis or interpretation is included, since this is the stated purpose of a number of other reports. This report will be useful to both scientists and managers who need ready access to some portion of the data on a regular basis. With this report it is possible to quickly examine seasonal patterns, compare conditions at …

Public Beach Assessment Report Aqua-Po Stafford County, Virginia, Deborah Linden, Donna Radcliffe, C. Scott Hardaway Jr., Suzette Kimball

Reports

The Aqua-Po Public Beach report is the first in a series of reports on the public beaches in the Commonwealth of Virginia. There are 14 localities with public beaches totaling about 23 miles of shoreline. The public beach reports are an assessment of the history of each public beach and their current status in terms of loss of beach fill and maintenance needed. This is measured by the beach monitoring program sponsored by the Virginia Board on the Conservation and Development of Public Beaches.

Nontidal Wetland Functions And Values, Maryann Wohlgemuth, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

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

Virginia Wetlands Reports

• Black Duck. Walter I. Priest, III
• Atlantic Menhaden. Lyle Varnell
• Back Bay Wetlands Inventory. Walter I. Priest, III and Sharon Dewing
• Mean High Water Mark and How to Locate it. Carvel Blair

Primary Producers And Decomposers Of Intertidal Flats, Maryann Wohlgemuth, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Water Quality In Chesapeake Bay : Virginia Portion, Water Year 1989 : A Report To The Virginia Water Control Board, Kevin Curling, Bruce Neilson

Reports

The purpose of this report is to characterize water quality conditions during the 1909 water year, October 1988 through September 1989. For the most part, the information is provided in graphical format. Only data for the Virginia portion of Chesapeake Bay is included. No data analysis or interpretation i:s included, since this is the stated purpose of a number of other reports a. We believe that the report will be useful to both scientists and managers who need ready access to some portion of the data on a regular basis. With this report one could, for example, quickly examine seasonal …

Water Quality In Chesapeake Bay : Virginia Portion, Water Year 1985 : A Report To The Virginia Water Control Board, Kevin Curling, Bruce Neilson

Reports

The purpose of this report is to characterize water quality conditions during the 1985 water year, October 1984 through September 1985. For the most part, the information is provided in graphical format. Only data for the Virginia portion of Chesapeake Bay is included. No data analysis or interpretation is included, since this is the stated purpose of a number of other reports. We believe that the report will be useful to both scientists and managers who need ready access to some portion of the data on a regular basis. With this report one could, for example, quickly examine seasonal patterns, …

Oyster Spatfall In Virginia Waters: 1990 Annual Summary, Bruce J. Barber

Reports

The Virginia Institute of Marine Science (VIMS) conducts surveys ofoyster spatfall (or "setting") in Virginia waters throughout the summer reproductive period. This survey provides an estimate of the potential of a particular area for receiving a "strike" or set of oysters on the bottom and helps define the timing of setting events. Information obtained from this effort is valuable to the Virginia Marine Resources Commission (VMRC) for its shell repletion program, and to private oyster growers, both of which are interested in maximizing the timing of shell planting. In addition, by maintaining a long-term data base, trends in spatfall throughout …

Status Of The Major Oyster Diseases In Virginia 1990 A Summary Of The Annual Monitoring Program, Eugene M. Burreson

Reports

No abstract provided.

Coastal Resources And The Permit Process: Definitions And Jurisdictions, Julie G. Bradshaw, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Ecological Risk Assessment For Highways In The Chesapeake Bay Watershed, Robert B. Atkinson, J. Cairns Jr., Bruce Wallace, James E. Perry

VIMS Books and Book Chapters

The population of coastal counties in the United States is over six-fold higher than non-coastal counties and population density along the Atlantic coast is much greater than all other coasts in the nation. Many areas around the Chesapeake Bay watershed are participating in this growth and extensive interstate construction is planned for this region. A wide array of primary ecological risks to the Chesapeake Bay exists, and may be classified as biological, physical, or chemical. Biological risks range from physical threats to motorists and animals to genetic risks to local flora and fauna populations. Island biogeography theory can be used …