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Articles 181 - 194 of 194

Full-Text Articles in Ocean Engineering

Ecosystem Analysis Of Water Column Processes In The York River Estuary, Virginia: Historical Records, Field Studies And Modeling Analysis, Yongsik Sin Jan 1998

Ecosystem Analysis Of Water Column Processes In The York River Estuary, Virginia: Historical Records, Field Studies And Modeling Analysis, Yongsik Sin

Dissertations, Theses, and Masters Projects

Analyses of EPA long-term datasets (1985--1994) combined with field studies and ecosystem model development were used to investigate phytoplankton and nutrient dynamics in the York River estuary. Analysis of the EPA dataset showed that algal blooms occurred during winter-spring followed by smaller summer blooms. Peak phytoplankton biomass during the winter-spring blooms occurred in the mid reach of the mesohaline zone whereas during the summer bloom it occurred in the tidal fresh-mesolialine transition zone. River discharge appears to be the major factor controlling the location and timing of the winter-spring blooms and the relative degree of potential nitrogen (N) and phosphorus …


The Study Of Wave-Blocking And Current Effects On Nonlinear Interactions Of Shallow-Water Waves Using Advanced Boussinesq Models, Qin Chen Jul 1997

The Study Of Wave-Blocking And Current Effects On Nonlinear Interactions Of Shallow-Water Waves Using Advanced Boussinesq Models, Qin Chen

Civil & Environmental Engineering Theses & Dissertations

The first part of this work focuses on the derivation of enhanced Boussinesq-type equations for the combined motion of waves and currents in shallow water areas.

The strategy proposed in this work is to couple two known methods which are the sponge layer concept suitable for short waves and Sommerfeld radiation condition for currents. This coupling method provides satisfactory non-reflective boundaries for the simulation of fully coupled wave/current motion as demonstrated by the numerical experiments. We verify the model against the well known solutions based on the existing theories and good agreement has been observed. The numerical results confirm the …


A Design Of A Marine Radar Mast System For Minimum Vibration, Suey-Yueh Hu Jan 1997

A Design Of A Marine Radar Mast System For Minimum Vibration, Suey-Yueh Hu

Dissertations and Theses @ UNI

This experimental research focused on four areas: (a) the design of a new procedure for imitating the dynamic behavior of an electronic base plate on a radar mast system; (b) determination of a reasonable oscillation modal state; (c) avoidance of the destruction of the ability of the radar on the mast of a ship to receive and analyze incoming signals; and (d) design of a vibration absorber and vibration isolator based on an oscillation frequency. An adapted design for the vibration absorber and vibration isolator contributed to the prevention of excessive amplitude being produced by random forces acting upon a …


Impact Of Artificial Reef Associates On Macrobenthic Community Structure In Florida Bay, Heinz Michael Proft Jan 1995

Impact Of Artificial Reef Associates On Macrobenthic Community Structure In Florida Bay, Heinz Michael Proft

Dissertations, Theses, and Masters Projects

No abstract provided.


Crassostrea Virginica On Constructed Intertidal Oyster Reefs: The Effects Of Tidal Height And Substrate Level On Settlement, Growth, And Mortality, Ian K. Bartol Jan 1995

Crassostrea Virginica On Constructed Intertidal Oyster Reefs: The Effects Of Tidal Height And Substrate Level On Settlement, Growth, And Mortality, Ian K. Bartol

Dissertations, Theses, and Masters Projects

No abstract provided.


Directional Wave Spectra Using An Acoustic Doppler Current Profiler, William T. Stockhausen Jan 1994

Directional Wave Spectra Using An Acoustic Doppler Current Profiler, William T. Stockhausen

Dissertations, Theses, and Masters Projects

No abstract provided.


Dynamics Of Fish Assemblages Associated With An Offshore Artificial Reef In The Southern Mid-Atlantic Bight, Aaron J. Adams Jan 1993

Dynamics Of Fish Assemblages Associated With An Offshore Artificial Reef In The Southern Mid-Atlantic Bight, Aaron J. Adams

Dissertations, Theses, and Masters Projects

No abstract provided.


Characterization Of Anti-Tumor Immunity In Oyster Toadfish (Opsanus Tau), And The Effects Of 7,12 -Dimethylbenz(A)Anthracene On This Immune Response, Kenneth R. Seeley Jan 1993

Characterization Of Anti-Tumor Immunity In Oyster Toadfish (Opsanus Tau), And The Effects Of 7,12 -Dimethylbenz(A)Anthracene On This Immune Response, Kenneth R. Seeley

Dissertations, Theses, and Masters Projects

Cell-mediated lysis of cultured tumor target cells by nonspecific cytotoxic cells (NCC) was examined in the oyster toadfish (Opsanus tau), an estuarine teleost. NCC activity was evaluated in cells taken from the head kidney, peripheral blood, spleen and peritoneal cavity. NCC activity was a property of plastic nonadherent cells which lacked phagocytic activity, indicating that in terms of their functional capacity, the cells which mediate nonspecific cytoxic immune responses in oyster toadfish do not appear to be monocytes or macrophages. However, light and electron microscopic examination of these cells revealed that morphologically, they resemble monocytes and macrophages. A new technique …


Interspecific And Intraspecific Variability In Placoid Scale Morphology In Relation To Body Form Variability In Squaliformes, Christopher R. Tabit Jan 1993

Interspecific And Intraspecific Variability In Placoid Scale Morphology In Relation To Body Form Variability In Squaliformes, Christopher R. Tabit

Dissertations, Theses, and Masters Projects

An ontogenetic series of nine species; Centrophorus granulosus, Centroscymnus coelolepis, Dalatias licha, Deania calcea, Echinorhinus cookei, Isistius brasiliensis, Oxynotus centrina and Squalus acanthias were studied to determine swimming capabilities, boundary-layer flow conditions and placoid scale functional morphologies. Body morphometric variables included the girth and the distance from snout to the orbitals, origin of the median and paired fins, and the caudal peduncle, body and fin surface area, fin aspect ratios and caudal fin angles. Placoid scales were sampled from sixteen regions across the body. Morphometric variables included the number of scales per area of integument, scale crown width, length and …


Beach Forms Induced By Coastal Structures Forming Embayments In Fetch-Limited Environments, Jian Hua Li Jan 1990

Beach Forms Induced By Coastal Structures Forming Embayments In Fetch-Limited Environments, Jian Hua Li

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effects Of Shading By Open-Pile Structures On The Density Of Spartina Alterniflora, Heather L. Mcguire Jan 1990

The Effects Of Shading By Open-Pile Structures On The Density Of Spartina Alterniflora, Heather L. Mcguire

Dissertations, Theses, and Masters Projects

No abstract provided.


Recommendations For Amelioration Of Legal And Environmental Concerns About Mining Of Deepsea Deposits Of Polymetallic Sulfides, Michael P. De Luca Jan 1986

Recommendations For Amelioration Of Legal And Environmental Concerns About Mining Of Deepsea Deposits Of Polymetallic Sulfides, Michael P. De Luca

Dissertations, Theses, and Masters Projects

No abstract provided.


Late Cenozoic Landforms, Stratigraphy And History Of Sea Level Oscillations Of Southeastern Virginia And Northeastern North Carolina, Pamela Crowson Peebles Jan 1984

Late Cenozoic Landforms, Stratigraphy And History Of Sea Level Oscillations Of Southeastern Virginia And Northeastern North Carolina, Pamela Crowson Peebles

Dissertations, Theses, and Masters Projects

A depositional model accounting for the stratigraphic sequences which accumulate during a marine transgression across a dissected coastal plain aids in understanding the geologic history of southeastern Virginia and northeastern North Carolina. Application of this model to the Shirley Formation (middle Pleistocene) and the Sedgefield and Lynnhaven members of the Tabb Formation (late Pleistocene) allows delineation of (1) the facies within, (2) the areal extent of, and (3) the landforms associated with these lithostratigraphic units. Facies within each lithostratigraphic unit consist of (1) a vertical succession from local, basal, channel-fill deposits and coarse, basal, lag deposits which grade upward into …


Water Wave Refraction With Non-Linear Theory, Im Sang Oh Oct 1981

Water Wave Refraction With Non-Linear Theory, Im Sang Oh

OES Theses and Dissertations

Two different kinds of wave refraction models are formulated in the present study using Stokes' third order wave theory. One type of model is utilized in a parametric study employing several different topographies. Wave trajectories obtained from this model, when obtained by using first and third order wave theory with and without the consideration of energy dissipation, show considerable differences. These differences are examined in more detail for a bottom of constant slope: (1) An approximate 10% difference occurs between the refraction coefficients obtained using the first and the third order wave theory. (2) Considerably different ray trajectories are detected …