Physical Sciences and Mathematics Commons^™

Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne

Biological Sciences Theses & Dissertations

Macrobenthic invertebrates of an industrialized seaport ecosystem were studied seasonally from October, 1977 through July, 1978. Five stations were selected along the Southern Branch of the Elizabeth River, Virginia. The stations ranged from an area of heavy industrialization to a non-urbanized environment. At each station, bottom water was measured for salinity, temperature, dissolved oxygen, and pH. Within each sampling area, macrobenthic infauna! invertebrates were collected from in and out of channel sites along with sediment samples for various types of physicochemical analysis.

Community structure was spatially homogeneous at station sites and throughout the stations along the River. Slightly acidic pH …

Isolation And Enumeration Of Enteric Viruses From Primary Wastewater Sludge, Michael Wayne Nath

Biological Sciences Theses & Dissertations

The presence of large numbers of enteric viruses in wastewaters has resulted in concern regarding their significance and consequences for humans. Assessments of relative significance or consequences may most accurately be made following precise measurements of the range of virus types and amounts in wastewaters and sludges and after epidemiological considerations. In this study, results are presented pertaining to enteric virus isolation, concentration, and enumeration from primary wastewater sludges.

As an integral part of a comparison of isolation procedures, several anionic surfactants were examined for extraction of enteric viruses from primary wastewater sludges. Plaquing efficiencies for poliovirus type 2 and …

Surface Circulation And Horizontal Diffusion Processes Of The Lower Chesapeake Bay, Frederick A. Hilder

OES Theses and Dissertations

A Lagrangian method utilizing clusters of four or five buoyed drogues is used to study the surface circulation and horizontal diffusion processes of the lower Chesapeake Bay. The study area encompasses some 160 km² and includes the area north of Thimble Shoal Channel, southwest of Chesapeake Channel and west of the Chesapeake Bay Bridge and Tunnel. Eleven trials utilizing buoyed drogues were conducted in the time frame February to October, 1979. Four trials were interrupted when buoys entered neighboring channels or dispersed too far for tracking, so that a total of sixteen runs were completed on the eleven trial …

Influence Of Nonequilibrium Radiation And Shape Change On The Flowfield Of A Jupiter Probe With Ablation And Mass Injection, Sundaresa Venkata Subramanian

Mechanical & Aerospace Engineering Theses & Dissertations

The influence of nonequilibrium radiative energy transfer and the effect of probe configuration changes on the flow phenomena around a Jovian entry body is investigated. The radiating shock-layer flow is assumed to be axisymmetric, viscous, laminar and in chemical equilibrium. The radiative transfer equations are derived under nonequilibrium conditions which include multi-level energy transitions. The equilibrium radiative transfer is calculated with an existing nongray radiation model which accounts for molecular band, atomic line and continuum transitions. The nonequilibrium results are obtained with and without ablation injection in the shock layer. The nonequilibrium results are found to be influenced greatly by …

Aspects Of Larval Ecology Of Squilla Empusa (Crustacea, Stomatopoda) In Chesapeake Bay, Steven G. Morgan

OES Faculty Publications

Larvae of Squilla empusa were collected from the plankton and were laboratory-reared in 16 combinations of temperature and salinity to determine their tolerances. Larvae survived longer and molted more frequently when reared at 25%, and 20° or 25° C, which corresponds to the natural conditions of Chesapeake Bay when the larvae were collected.

A 2 year planktonic survey conducted in the lower region of the bay by the Virginia Institute of Marine Sciences was compared with a survey made at the bay mouth in 1976. The seasonal occurrence of Squilla empusa larvae extended from the last week of July until …

Ocean Chlorophyll Studies From A U-2 Aircraft Platform, Hongsuk H. Kim, Charles R. Mcclain, Lamdin R. Blaine, William D. Hart, Larry P. Atkinson, James A. Yoder

CCPO Publications

Chlorophyll gradient maps of large ocean areas were generated from U-2/OCS data obtained over test sites in the Pacific and the Atlantic Oceans. The delineation of oceanic features using the upward radiant intensity relies on an analysis method which presupposes that radiation backscattered from the atmosphere and the ocean surface can be properly modeled by using a measurement made at 778 nm. The calculation of atmospheric radiance was performed by using a method developed by J.V. Dave. An estimation of the chlorophyll concentration is performed by properly ratioing radiances measured at 472 and 548 nm after removing the atmospheric effects. …

A Note On The Degree Of Approximation With An Optimal, Discrete Polynomial, J. J. Swetits, B. Wood

Mathematics & Statistics Faculty Publications

A saturation theorem and an asymptotic theorem are proved for an optimal, discrete, positive algebraic polynomial operator. The operator is based on the Gauss-Legendre quadrature formula.

An Algorithm For The Electromagnetic Scattering Due To An Axially Symmetric Body With An Impedance Boundary Condition, F. Stenger, M. Hagmann, J. Scheing

Computer Science Faculty Publications

Let B be a body in R³, and let S denote the boundary of B. The surface S is described by S = {(x, y, z): (x² + Y²)^½= ƒ(z), -1≤ z ≤ I}, where ƒ analytic function that is real and positive on (-1, 1) and ƒ(±1) = 0. An algorithm is described for computing the scattered field due to a plane wave incident field, under Leontovich boundary conditions. The Galerkin method of solution used here leads to a block diagonal matrix involving 2M …

Luminescence In Slipped And Dislocation-Free Laser-Annealed Silicon, R.H. Uebbing, P. Wagner, H. Baumgart, H. J. Queisser

Electrical & Computer Engineering Faculty Publications

Photoluminescence of cw laser-annealed silicon shows a dramatic difference in electronic behavior of the reconstructed material depending upon either creation or suppression of dislocations. Beyond a critical exposure time slip appears, and the luminescence of these samples is dominated by dislocation-related defect levels.

Phytoplankton Studies Within The Virginia Barrier Islands I. Seasonal Study Of Phytoplankton In Goose Lake, Parramore Island, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton of Goose Lake, an oligohaline lake on Parramore Island, was studied for one year. The populations consisted primarily of ultraplankton and nanoplankton-sized forms with diatoms and chlorophyceans dominant most of the year. A general pattern of seasonally higher cell concentrations in early summer and fall was noted, with an unidentified ultraplankton-sized component prominent throughout the collection period. A list of 154 species is given.

The Association Of 5.8 S With 28s Ribosomal Rna, Nandita Banerjee

Chemistry & Biochemistry Theses & Dissertations

5.8S rRNA is a low molecular weight ribosomal RNA which is noncovalently bonded to the larger ribosomal subunit 28S rRNA; through its 3' end and through its 5' end. This interaction is an integral part of the ribosome, and plays an important role in the ribosome structure and function.

There is a high degree of homology between the 5.8S rRNA primary structures of rat, turtle and chicken. The base sequence of rat 5.8S rRNA differs only in one position from that of turtle and in three positions fr.om that of cl1.icken. Tl1ere is a single purine substitution at the 5' …

An Analysis Of Bathymetric Change In Lower Chesapeake Bay, John C. Ludwick

OES Faculty Publications

The purposes of the work-reported in this document are (a) to determine the magnitudes and patterns of water-depth changes in lower Chesapeake Bay within a control area centered on Thimble Shoal Channel; (b) to interpret these changes, insofar as possible, in terms of sediment movements and/or bed erosion and lateral shifting of large shoals and tidal current channels; and (c) to .deduce the relationship of these changes, insofar as possible, to changes in the Chesapeake Bay shoreline from Willoughby Spit to the area of Cape Henry. Virginia.

Feeding Morphologies And Distribution Patterns Of Marine Cladocera In The Lower Chesapeake Bay, Sandra Layne Gilchrist

OES Theses and Dissertations

Temporal and spatial distributions of marine cladocera in the lower Chesapeake Bay estuary were observed over a year-long sampling period. The distributions of cladoceran species throughout the Bay were studied in relation to temperature and salinity. A survey of the species over the entire Bay is included to establish distribution patterns of the various species during a short time period.

Theoretical mathematical principles were used to predict feeding abilities of the Bay species. Mouthparts are described qualitatively and quantitatively to infer function. A mandibular index developed by Itoh (1970) was revised and employed in evaluating feeding methods interspecifically and interspecifically. …

The Spatial And Temporal Distribution Of Fish Eggs And Larvae In Hempstead Bay Estuary, Joseph Adelard Lessard

OES Theses and Dissertations

The ichthyoplankton of Hempstead Bay estuary was sampled from December 1972 to mid March 1974. Eleven stations were sampled by towing a 0.5 meter diameter plankton net. Eggs were most abundant during June and July with an average concentration calculated to be above 5,500/100m³. Egg densities were the lowest during the fall and winter. Larvae were most frequently taken from March through July with densities varying greatly among the samples. The eggs of Brevoortia tyrannus, Anchoa mitchilli, Tautoga onitis, Tautogolabrus adspersus, and Scophthalmus aguosus and the larvae of Menidia menidia, Ammodvtes hexapterus and Pseudopleuronectes americanus constituted most …

Franck Condon Factors And R-Centeroids For Six Diatomic Molecules, Patricia M. Fazio

Physics Theses & Dissertations

The Franck Condon factor is defined as the square of the overlap integral and is so named because of its ties with the Franck Condon Principle. The r-centroid is the internuclear separation associated with the electronic transition of the diatomic molecule. The physical meaning of these integrals is discussed. Two methods for construction of the wavefunctions are presented. Both methods employ the Morse Potential Energy function. The first method calculates the integrals using the analytic wavefunction of Morse and the second method has numerically constructed wavefunct!ons. The twelve transitions and six diatomic molecules studied include; B ²Σ+ to X …

Production Of A Population Of The Stout Razor Clam (Tagelus Plebeius Solander) In A Virginia Estuary, Mark James Grussendorf

OES Theses and Dissertations

The annual net secondary production of the stout razor clam, Tagelous plebeius, was estimated at three sites on an intertidal sand flat at Lynnhaven Inlet, Virginia. Samples were taken at six week intervals for one year. The range of net production (P), mean annual biomass (B), and P/B ratios was 18.3-28.7 g m^-2year^-1, 27.2-53.3 g m^-2, and 0.54-0.67, respectively. The total biomass did not show significant seasonal variation though differences between sites were significant. Production varied temporally but was not significantly different between sites.

The Effects Of Proton Irradiation On The Absorption Of Multi Component Glasses, Marcia Frances Bartusiak

Physics Theses & Dissertations

Three Schott glasses typically used in space technology -­ LaK 21, KzFS N4, and LF 5 -- were irradiated with 85 MeV protons. Induced absorption spectra were determined for each glass after varying fluences of radiation. It was found that the spectra for each glass can be fitted with three Gaussian shaped bands in the near ultraviolet-visible region, while a fourth Gaussian characterizes the absorption edge. For doses up to 10⁷ rads, the dependence of the induced absorption a on total dose is accurately described by the saturating exponential function a(Φ)= a_s (1 - e-^{-b Φ} ) …

Turbulence Spectra In A Well-Mixed Estuary, Jong Yul Chung

OES Theses and Dissertations

This dissertation is an attempt to determine and describe some of the turbulent process in a well-mixed estuary. The processes are identified by the study of turbulent velocity fluctuations. These velocity records have been analyzed using standard digital methods to obtain spectral density, spectral energy, and cross-spectra of velocity. In order to study the generation and transfer of the turbulent moment and energy, and the intermittent nature of the so-called "Bursting or "ejections and sweeps," the distribution of u, v, w, and the Reynolds stress has been studied.

Note: On Summability And Positive Linear Operators, J. J. Swetits

Mathematics & Statistics Faculty Publications

Quantitative estimates for approximation by positive linear operators are obtained with the use of a summability method which includes both convergence and almost convergence.

Additional Comments On Reproductive Strategies And Population Fluctuations In Microtine Rodents, Michael S. Gaines, William M. Schaffer, Robert K. Rose

Biological Sciences Faculty Publications

Recently, Schaffer and Tamarin (1973) proposed a model relating changes in reproductive effort (RE) to fluctuating densities in microtine rodents (lemmings and voles). They assumed (and presented data supporting this assumption) that the major effect of increased crowding would be a reduction in survival among prereproductives, thereby lowering the effective fecundity (Schaffer and Rosenzweig 1977) of their parents. As a consequence, Schaffer and Tamarin argued that the optimal reproductive expenditure, E(N), should decline with increasing population size, N. They also deduced the shape of the zero-growth isocline, N*(E), for differing levels of RE and plotted both E(N) and N*(E) on …

Sufficiency Of A Numerical Downstream Continuation, Charlie H. Cooke

Mathematics & Statistics Faculty Publications

(First paragraph) Customarily one does not impose n-th order boundary conditions on the solution of initial/boundary value problems whose characterizing partial differential equations are also n-th order. However, conjecture that such problems are not well-posed, or that a solution might not exist, is not always justified [l]. Perhaps a physically more natural example is provided by problems of computational fluid dynamics. Here boundary conditions which correctly should be applied at an infinite distance downstream from the region of interest are for computational convenience often applied at a finite location [2]. Results of numerical experimentation on viscous flows governed by …

Alkalinity And Ph In The Southern Chesapeake Bay And The James River Estuary, George T. F. Wong

OES Faculty Publications

The ranges of alkalinity and pH in the southern Chesapeake Bay and the James River estuary were 2.25 meq·liter⁻¹ at 32‰ to

Stable Equilibrium Statistical States For Spheromaks, George Vahala, Linda L. Vahala

Electrical & Computer Engineering Faculty Publications

Incompressible nondissipative magnetohydrodynamic turbulence is treated for spherical systems. From the absolute equilibrium expectation values of the fields one can investigate those initially quiescent states for which no large mean square velocity will develop. This stable state is force-free and gives rise to the Hill vortex structure for the magnetic flux surfaces.

The Comparative Ecology Of Two Populations Of The Troglobitic Isopod Crustacean Lirceus Usdagalun (Asellidae), James Alexander Estes

Biological Sciences Theses & Dissertations

Aquatic communities of two caves in Lee Co., Virginia, were compared, and an examination was made of the life history phenomena of the troglobitic isopod Lirceus usdagalun. Measurements of physical and biological parameters were made in Thompson Cedar Cave and Gallohan Cave No. l. A contagious distribution was exhibited by populations of L. usdagalun in both caves and also by the population of another troglobitic isopod, Caecidotea recurvata, in Gallohan Cave No. 1. This distribution was attributed to aggregations of individuals which were considered to occur in areas of preference or optimal habitat patches. Lirceus usdagalun exhibited a …

Spring Phytoplankton Composition And Distribution In Coastal Waters Between Nova Scotia And The Chesapeake Bay, Larry William Neal

OES Theses and Dissertations

This investigation was directed toward satisfying a recognized lack of informat on regarding phytoplankton composition and density in shelf waters between Nova Scotia and the Chesapeake Bay. A sedimentation technique was used in determining the phytoplankton composition of 99 samples collected between 2 March and 3 April 1971. Chlorophyll-a samples collected concurrently were analyzed fluorometrically. Simple correlation analyses were utilized in describing distributional patterns of phytoplankton density and chlorophyll-a concentration with respect to water temperature, salinity, density, depth, distance from shore and latitude. Analysis of variance was employed in assessing regional differences in phytoplankton density and chlorophyll-a.

The phytoplankton flora …

The Distribution Of Several Metals And Cation Exchange Capacity In Sediment Fractions From An Artificial And Natural Marsh, James River, Virginia, William Nivens

OES Theses and Dissertations

In order to examine the mechanisms by which Fe, Mn, Ca, Zn, Cu, Ni and Pb are bound in sediments, a sequential selective extraction procedure was employed on sediment samples collected at an experimental dredge disposal marsh and a neighboring natural marsh located near Windmill Point, James River, Va. The metal concentrations were determined in six phases, interstitial water, exchangeable, easily reducible (oxides of Mn), organic, moderately, reducible (oxides of Fe), and residual fractions. In addition, the cation exchange capacity (CEC) of the sediments was determined as well as the actual role of organics and colloidal iron coatings as they …

Mercury, Copper, And Zinc In Selected Ichthyofauna Of Lower Chesapeake Bay And Hampton Roads, Virginia, W. Bruce Aitenhead

OES Theses and Dissertations

Anchovys, croaker, spat, summer flounder and hogchokers were collected monthly to seasonally from November 1972 to October 1973 at three locations in the southern Chesapeake Bay region of Virginia.

The concentrations of mercury, copper and zinc were determined by atomic absorption spectrophotometry in whole fishes. Metal concentration varied with species and location. Anchovys had the highest mean concentrations of mercury and zinc while hog- chokers had the highest mean copper concentration. Mercury levels exceeding O.5 ppm were observed in species from all three loca- tions, but maximum heavy metal concentrations per species were highest in Craney Island fishes.

Temporal variations …

Conservation According To The Pure Theory Of Exhaustible Resources, George Lymbouris

Economics Theses & Dissertations

The objective of this thesis is to develop a theory for defining optimal conservation and applying definition to the prevailing rate of domestic petroleum production. Optimal conservation is defined as action designed to achieve or to maintain, from the point of view of society as a whole, the maximum present value of natural resources (or of a natural resource). The proper "action" is defined according to the pure theory of exhaustible resources. The literature survey is a chronological series of articles concerning this theory.

Through building a model which shows that optimal conservation occurs when the marginal internal rate of …

The Response Of An Idealized Continental Shelf To Atmospheric Forcing, Paul Francis Moersdorf

OES Theses and Dissertations

The response of continental shelf water to cooling and wind stress is investigated using a two-dimensional numerical model. The topography of the east coast continental shelf was idealized by connecting a shallow (50 m) rectangular nearshore basin to a deeper (100 m) rectangular offshore basin. Numerous cases were examined using a wide range of values for both the air•sea temperature difference and the Wind speed, although the direction of the wind was always perpendicular to the coast.

The model predicts large excursions of shelf water offshore, and the subsequent surfacing of lower waters. Upwelling velocities of close to five meters …

Experiments In Attempted Interspecific And Interpopulational Hybridzation Of Grass Shrimp Of The Genus Palaemonetes (Caridea Palaemonidae), Mark Andrew Boston

OES Theses and Dissertations

The present study investigates the interfertility of Palaemonetes populations, Interspecific crosses were attempted between representatives of sympatric :populations of P. pugio, P. vulgaris, and P. intermedius, Intraspecific crosses were undertaken between geographically separated :populations of P. pugio. Laboratory conditions of 25°c, 25°/oo, and 14.5 hour photoperiod per day were maintained for all breeding attempts, Under these conditions interspecific hybridization of Palaemonetes pugio and P. vulgaris was not feasible. P. intermedius could not be hybridized with P. pugio and P. vulgaris. At 40 days of age P. pugio juveniles were significantly larger than P. vulgaris juveniles of …