Physical Sciences and Mathematics Commons^™

The Photosynthetic Action Spectra Of The Phytoplankton And Their Role In Governing Spatial And Temporal Distribution: A Numerical Modeling Approach, William Morrow Willis

OES Theses and Dissertations

In the present study a numerical modeling approach is employed to examine the role of division spedific differences in photosynthetic action spectra in governing the relative size of diatom and dinoflagellate carbon synthesis along various marine light regime gradients. A radiative transfer model taking into account both Rayleigh and Mie atmospheric optical properties is employed to define the light regime incident on the sea surface. The hydrospheric light regime is defined by an exponential decay model with a correction for diffuse back scatter. Taken together, the atmospheric and hydrospheric models define the spectral composition and intensity of light in the …

Approximation By Discrete Operators, J. J. Swetits, B. Wood

Mathematics & Statistics Faculty Publications

A discrete, positive, weighted algebraic polynomial operator which is based on Gaussian quadrature is constructed. The operator is shown to satisfy the Jackson estimate and an optimal version is obtained.

The Results Of Four Oceanographic Cruises In The Georgia Bight, L. P. Atkinson

CCPO Publications

During 1973 and 1974 we conducted four oceanographic cruises in the Georgia Bight with the purpose of gaining background seasonal data with which to plan more scientific experiments. In this technical report the data are presented in graphical form with interpretation. The data itself was published in two technical reports (Atkinson, 1975 and 1976). Some of the interpretations in this report will be given in more detail in published journal articles.

The Chemical And Biological Effect Of A Gulf Stream Intrusion Off St. Augustine, Florida, Larry P. Atkinson, Gustav-Adolf Paffenhöfer, William M. Dunstan

CCPO Publications

During a 3-day anchor station in shelf waters off St. Augustine, Florida we observed the effect of an intruding mass of deeper Gulf Stream water. The shelf waters were relatively low in nutrients and salinity while the Gulf Stream waters were high in salinity and nutrients. Onshore currents correlated with increases in nitrate and chlorophyll concentrations.

The advection of higher nutrient Gulf Stream water coincided with high chlorophyll (∼ mg chl a m⁻³) concentrations and dense populations of Phaeocystis pouchetii (up to 3.12 × 10°1⁻¹). Zooplankton sampling was impossible in the bottom layer because of the …

Complementary Extremum Principles, J. Swetits, C. Rogers

Mathematics & Statistics Faculty Publications

Important complementary extremum principles are generated without recourse to general variational theory. The results are illustrated by an application to a class of boundary value problems in Magnetohydrodynamics.

The Relationship Of Bottom Sediments To The Current-Generated Topography On Crumps Bank And Willoughby Bank, Southern Chesapeake Bay, Virginia, Eugene Robert Brush

OES Theses and Dissertations

Crumps Bank and Willoughby Bank in Southern Chesapeake Bay are an area of varying topography. The area is bounded by two large bridge-tunnel spans, the dredged Thimble Shoal Channel borders it to the north, and the Ocean View section of Norfolk, Virginia lies to the south. The purpose of this investigation is to determine the relationship of the bottom sediments of Crumps Bank and Willoughby Bank.to the current-generated topography, and that this topography is the result of tidal currents.

The bathymetry, bottom sediment characteristics, bottom tidal currents, and the correlation of depth to various sediment parameters were examined to determine …

Suspended Matter And Light Attenuation In A Turbid Estuary, Daniel E. Campbell

OES Theses and Dissertations

A study was made in Hampton Roads, Virginia, to characterize the suspended matter and to investigate its relationship to the light attenuation coefficient. The study gives a detailed description of the seston and its variations with time and space. An evaluation of the light attenuation coefficient as an indicator of seston distributional parameters was made.

The distribution of the suspended matter is obtained through gravimetric, Coulter counter and microscopic analyses. Microscopic analysis is employed to determine the composition of the seston and ATP determinations give the amount of living biomass. The suspended matter is characterized in terms of weight, numbers, …

A Study Of The Gas-Solid Reaction Between Hydrogen Sulfide And Mercury(I) Chloride; Development Of A Method For Determination Of Atmospheric Hydrogen Sulfide, Eric H. De Carlo

Chemistry & Biochemistry Theses & Dissertations

The possibility of measuring hydrogen sulfide indirectly by measuring the mercury evolved from the gas-solid reaction between hydrogen sulfide and mercury(I) chloride was studied. DMCS treated glass wool was coated with mercurous chloride and used as a conversion material. The response to hydrogen sulfide was studied as a function of concentration and temperature. The possible interference of other sulfur gases and water was examined.

The studies indicated that hydrogen sulfide could be determined at concentrations as low as 15 ppb. It was found that mercaptans would actively interfere with the hydrogen sulfide to mercury conversion, but that sulfur dioxide would …

Description Of The Larval Development Of Squilla Empusa Say (Crustacea Stomatopoda) With Aspects Of Larval Ecology In Chesapeake Bay, Steven Gaines Morgan

OES Theses and Dissertations

Larvae of Sguilla empusa were collected from the plankton and were reared in the laboratory to describe the pelagic larval development and the postlarval stage. Nine pelagic stages are passed through before the postlarval stage is attained.

The larvae reared for descriptive purposes were subjected to sixteen combinations of temperature and salinity to determine their tolerance to the two parameters. Larvae survived longer and molted more frequently when reared at 25°/oo and 20°C or 25°C, which corresponds to the natural conditions of the Chesapeake Bay when the larvae were collected.

A three year planktonic survey conducted in the lower region …

A Seasonal Study Of Phytoplankton Composition Abundance And Productivity In Back Bay, Virginia, Robert Ringgold Comegys

Biological Sciences Theses & Dissertations

Phytoplankton samples were collected monthly (August 1974-June 1975) at two stations in the Back Bay system of southeastern Virginia. Measurements of phytoplankton productivity and potentially influencing environmental parameters (water and air temperature, turbidity, depth, pH, salinity, dissolved oxygen) accompanied sample collections. A total of 106 phytoplankton species, representing six algal divisions and 54 genera were identified. Cyanophyta species were dominant at both stations in the warmer months of August, September, October, and June, and in April at one station only. In all remaining months, Chlorophyta species were dominant, indicating a seasonal shift in phytoplankton composition during winter and spring. The …

Sediment Interstitial Dissolved Mercury And Carbon Relationships In An Artificial And Natural Marsh, James River, Virginia, Apostolos Katsaounis

OES Theses and Dissertations

Thirty six sediment cores were collected during August, 1976 and January, 1977 in order to examine the relationships between dissolved organic carbon and total dissolved mercury in the interstitial water of two marshes located near Windmill Point, James River, 16 km downstream from Hopewell, Virginia. The Windmill Point marsh development site is a dredged material disposal island in the James River. The reference marsh which does not contain dredged material, is located 2.3 km upstream at Ducking Stool Point.

The concentrations of dissolved organic carbon and total dissolved mercury showed no significant difference between the two marshes. Trends in the …

The Effects Of Electron Irradiation On Mosfets, Mark D. Skeldon

Physics Theses & Dissertations

The characteristics of n and p-channel MOSFETs have been investigated while irradiated with electron radiation from Strontium 9Ø. The drain current vs. gate voltage of the p-channel MOSFET and the threshold voltage changes in n and p-channel MOSFETs have been studied with and without aluminum shielding. The switching characteristics and threshold voltage changes of COS/MOS dual input NAND gates have been investigated while exposed to electron radiation. Various methods of annealing the radiation damage to these devices is discussed.

Temperature And Salinity Tolerance Of The Larvae Of The Sand Shrimp, Crangon Septemspinosa (Say), Karen Lyttle Hinsman

OES Theses and Dissertations

The effects of temperature and salinity on the larval development of the sand shrimp, Crangon septemspinosa, were investigated in the laboratory using 30 combinations of temperature and salinity in a five by six factorial experiment. The five temperatures were 5°c, 10°c, 15°c, 20°c, and 25°c and the six salinities were 10°/oo, 15°/oo, 20°/oo, 25°/oo, 30°/oo and 35°/oo. Thirty-six larvae were used for each temperature-salinity combination. Temperature and salinity produced significant differences (1% level) in survival and the duration of larval development. Highest survival occurred at 15°c and 20°/oo. At optimum temperatures (15°c to 20°c) larvae exhibited the broadest tolerance …

Effect Of Nitrite And Nitrate On The Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthuis, Carl Bingham Hinesman

OES Theses and Dissertations

The effects of nitrite and nitrate on survival and larval development of the grass shrimp Palaemonetes pugio were investigated in the laboratory. Nitrite concentrations assayed were 0 (control), 0.5, 1.0, 10, 25 and 50 mg NO₂/1. Nitrate concentrations tested were 0 (control), 100, 250, 500, 1000 and 2000 mg NO₃/1. Temperature and salinity conditions were 25 C and 25 ‰, respectively, and all tests occurred in the dark. Thirty-six larvae were reared in each assay, twelve from each of three adult females.

Nitrite levels of'5 and 50 mg NO₂/1 significantly reduced survival of larvae …

A Baseline Study On The Possible Mechanisms Of Larval Stomatopod Distribution On The Carolina Shelf, Carl Robert Berman Jr.

OES Theses and Dissertations

The South Carolina Marine Resources Institute provided the author with 198 station samples containing 2,193 stomatopod larvae. These larvae had been collected during ichthyoplankton Bongo tows on five separate cruises aboard the Institute's vessel R/V DOLPHIN (February, 1972 to January, 1975). The larvae were examined microscopically and divided into early, middle, and late stages according to known growth criteria. The larval distribution was plotted geographically, by seasons, and larval density (larvae/m3) was graphed against distance offshore. Using these data, together with the circulation characteristics on the Carolina Shelf, significant distributional data appeared which supported the hypothesis that the stomatopod population …

Modes Of Gulf Stream Intrusion Into The South Atlantic Bight Shelf Waters, Larry P. Atkinson

CCPO Publications

Consideration is given to the intrusion of Gulf Stream waters into the shelf waters of the South Atlantic Bight. It is observed that three modes of intrusion may occur, depending on particular ambient shelf water density. They are override, interleave, and bottom intrusion. It is noted that: (1) except in January, when the shelf water densities are relatively higher, 20°C Gulf Stream water can form a bottom intrusion anywhere along the coast, (2) Gulf Stream waters of 24°C can only form bottom intrusions from April to November, and (3) the rest of the year, 24°C waters interleave or override.

Effect Of Compliant Wall Motion On Turbulent Boundary Layers, Dennis M. Bushness, Jerry N. Hefner, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

A critical analysis of available compliant wall data which indicated drag reduction under turbulent boundary layers is presented. Detailed structural dynamic calculations suggest that the surfaces responded in a resonant, rather than a compliant, manner. Alternate explanations are given for drag reductions observed in two classes of experiments: (1) flexible pipe flows and (2) water-backed membranes in air. Analysis indicates that the wall motion for the remaining data is typified by short wavelengths in agreement with the requirements of a possible compliant wall drag reduction mechanism recently suggested by Langley. Copyright © 1977 American Institute of Physics.

Feeding Ecology Of Black Sea Bass Centropristis Striata On An Artificial Reef Off Virginia (Perciforms: Serranidae), Ping K. Chee

OES Theses and Dissertations

The feeding ecology of the black sea bass, Centropristis striata, associated with artificial reefs shows seasonal and size-related changes. Monthly collections totaling 520 black sea bass taken from an artificial reef near the Chesapeake Light Tower, Virginia, between August 1975 and May 1976, were analyzed for food habits as revealed by number, volume, frequency of occurrence and a modified Index of Relative Importance.

The black sea bass feeds on the artificial reef as well as the adjacent areas. When food was abundant on the reef, food items from the reef and the surrounding area were consumed. Upon depletion of the …

Solar Magnetoatmospheric Waves-A Simplified Mathematical Treatment, John A. Adam

Mathematics & Statistics Faculty Publications

The inhomogeneous wave equation for a special class of magnetoatmospheric waves is formally solved, and the principle of stationary phase used to provide information on the group velocity properties of such waves. General results are presented concerning the associated mechanical energy flux. The basic problem considered is relevant to waves initiated by sudden events in the solar atmosphere.

Effect Of The Chesapeake-Elizabeth Sewage Outfall Virginia Beach, Virginia On The Distribution And Ecology Of Benthic Foraminifera, James M. Bates Jr.

OES Theses and Dissertations

Sediment and bottom water samples from seven stations at the Chesapeake Elizabeth sewage outfall, Virginia Beach, Virginia were collected in order to evaluate the effect of the outfall on benthic foraminifera. The top centimeter of sediment was analyzed for living and total (live plus dead) foraminiferal densities, chlorophyll a, sediment grain size, ATP, percentage of silt and clay, and total organic carbon. Bottom water salinity, temperature, and ammonia were also analyzed.

Living foraminiferal density increased from March to July and with distance from the outfall. Total foraminiferal density also increased from March to July. The set of environmental variables was …

The Effects Of Dredging On The Stability Of An Ebb-Tidal Delta, Lynnhaven Inlet, Virginia, Donald Keith Riggenbach

OES Theses and Dissertations

A channel was dredged in 1965 through the ebb-tidal delta of Lynnhaven Inlet, Virginia. The purpose of this study was to determine if this channel has affected the morphological configuration of the delta. It was proposed that the channel caused the dynamically stable delta to become unstable and change its morphology.

Bathymetric comparisons of seven surveys during the last 122 years, including one conducted during this investigation, show that prior to 1962 and the dredging operations, the delta had become dynamically stable. The present survey shows that the delta has changed its shape in response to the interaction of the …

Seasonal Distribution And The Retention Of Some Decapod Crustacean Larvae Within The Chesapeake Bay, Virginia, Joseph William Goy

OES Theses and Dissertations

Planktonic stages or 45 genera and species or decapod larvae were identified and staged from samples taken over a three year period in the lower portion and entrance area or Chesapeake Bay. The distribution of each larval stage of the decapod crustaceans found in the bay was determined and from this, the extent of the respective breeding season was deduced. In 1975, samples were taken monthly from stations along a transect at the baymouth, both at the surface and bottom. Two stations were also occupied over the tidal cycle in daylight and darkness. Evidence is presented that larvae of some …

A Comparative Study Of A Salt Water Impoundment With Its Adjacent Tidal Creek Pertinent To Culture Of Crassostrea Virginica (Gmelin), William D. Anderson Iii

OES Theses and Dissertations

Certain physical, chemical and biological characteristics associated with the culture of subtidal Crassostrea virginica were assessed in a salt water impoundment and its adjacent tidal feeder creek. Large seed oysters (initial y = 57.3 mm) were transferred from a somewhat polluted estuary of Charleston Harbor to floating, mid-water, and bottom hardware cloth trays (200/tray) in a four hectare pond. Identical trays at comparable depths were placed in the tidal creek and each location was sampled monthly for growth and survival. Surface and bottom water samples were collected weekly throughout the study and hourly during four seasonal 25 hour stations. Standard …

Evaluation Of Upwelling Infrared Radiance In A Nonhomogeneous Nonequilibrium Atmosphere, Sundaresa Venkata Subramanian

Mechanical & Aerospace Engineering Theses & Dissertations

The primary purpose of this study was to investigate the influence of vibrational nonequilibrium upon upwelling infrared radiance from the earth's atmosphere. Basic equations are presented for calculating the atmospheric transmittance, heating rates, and equilibrium and nonequilibrium upwelling radiances. By employing the Lorentz line-by-line model for spectral absorption, heating rates and upwelling radiances were calculated for equilibrium as well ·as nonequilibrium conditions in the spectral range of 4.6 μ CO and 3.3 μ 'CH₄ bands. For the spectral range of CO fundamental band, the influence of different 1~arameters on the upwelling radiance was also investigated. The results indicate that …

The Effect Of 4-Chlororesorcinol On The Growth Potential Of Dunaliella Tertiolecta Butcher (Dun Clone), John Anthony Chigges

OES Theses and Dissertations

Jolley (1973) identified and quantified 4-chlororesorcinol at the 1.2 μg/1 level in secondary treated sewage effluent as one of 17 stable organochlorine compounds. The present report presents the first data on the effect of 4-chlororesorcinol on the growth potential of the marine phytoplankter, Dunaliella tertiolecta Butcher (Dun clone).

The assay method used herein was that of the Marine Algal Assay Procedure: Bottle Test (EPA, 1974). An algal culture chamber was constructed capable of providing controlled temperature (18 ± 2°C) and light (400-500 ft-c) conditions. Four parameters were used to describe the growth response of D. tertiolecta including maximum specific growth …

Topography, Shallow Structure, And Sedimentary Processes Of The Atlantic Continental Slope Off The Carolina Coast, Robert Michael Fitchko

OES Theses and Dissertations

Analysis of 58 closely-spaced bathymetric and seismic profiles of the Carolina continental slope from the northern Blake Plateau to the vicinity of the North Carolina-Virginia state line (latitude 32• 30 'N to 36• 30 'N) indicates sharp contrasts in quantity of slumping and outcrop ledge continuity.

Terrestrial progradation and a relatively gentle slope characterize the area south of Cape Lookout, especially between Cape Romain and Cape Fear where sediment mantling is the greatest. Submarine canyons, slumps, and a steep slope are characteristic Between Cape Lookout and Cape Hatteras. North of Cape Hatteras, canyons and slumps are also common, though sediment …

Numerical Simulation Of Thermohaline Convection In The Mixed Layer Of The Ocean, Victor Eli Delnore

OES Theses and Dissertations

The intradiumal heating and cooling cycle of the mixed layer of a tropical ocean is investigated through the use of a pseudo-two-dimensional numerical model. Particular emphasis is given to two-component diffusion resulting from dynamic instabilities in the water column. The conservation equations for salt and heat include the effects of solar heating, horizontal advectlon, and turbulent fluxes at the sea surface, while wind mixing enter through the use of depth-dependent eddy diffusion coefficients resulting from the wave-orbital shear model of KitaigorodsldLy. All inputs are treated as functions of time-of-day, or calculated via the bulk aerodynamic method.

The entrainment fluxes of …

Stability And Local Effects Of An Offshore Sand Storage Mound, Dam Neck Disposal Site, Virginia Inner Continental Shelf, William Joslyn Saumsiegle

OES Theses and Dissertations

From 1967 to 1974 medium to coarse sand dredged from the Chesapeake Bay was stockpiled approximately three miles offshore of Dam Neck, Virginia in hopes that the sand could be recovered for local beach renourishment projects. The resulting mound was surveyed over a two year period to determine if the sand is being removed by wave and current action and if the creation of a new feature on the ocean bottom changes the wave refraction patterns and perhaps creates local erosion.

Bathymetric profiles across the storage mound show some apparent morphological changes, but a detailed analysis of this data is …

A Numerical Model For The Prediction Of Tides And Tidal Currents In The Lafayette River, Norfolk, Virginia, G. Mcallister Sisson

OES Theses and Dissertations

A prediction technique for tidal heights and currents in the Lafayette River of Norfolk, Virginia has been formulated and tested by the implementation of a two-dimensional numerical model employing the Navier-Stokes momentum equations and conservation of mass. The model operates on a spatially-fixed rectangular grid system by utilizing a multi-operation finite difference scheme which employs implicit and explicit solutions to the aforementioned equations. Forces due to bottom friction and Coriolis are taken into account. The only open boundary considered in the model is the river mouth, across which tidal height is specified temporally. Collected tidal height and current data at …

Test Variation In The Sand Dollar, Mellita Quinquiesperforata (Leske), George Glynn Rountree

OES Theses and Dissertations

Mellita quinguiesperforata is a common member of the benthos along the eastern coast of North America. This study considers variation of the test within the species, specifically: 1) variation in test weight, 2) variation in the length-width relationship, and 3) the average number of pore pairs in the ambulacral petals.

A total of 844 sand dollars from three localities was utilized: 1) Pass-a-Grill Beach, St. Petersburg, Florida,2) Bird Shoal, Beaufort, North Carolina, and 3) Fisherman Island, Virginia.

Animals were measured for length and width and the dry weight determined. Prediction equations for the size-weight relat1onships were computed for the three …