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Dissertations, Theses, and Masters Projects

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Articles 1231 - 1260 of 1876

Full-Text Articles in Physical Sciences and Mathematics

Market Interactions And Competition Between Public And Private Oyster Production And Supplies From Other States, Ya-Ke Hsu Jan 1993

Market Interactions And Competition Between Public And Private Oyster Production And Supplies From Other States, Ya-Ke Hsu

Dissertations, Theses, and Masters Projects

Oyster production in Virginia has declined dramatically in the past ten years, causing Virginia oyster processors to rely increasingly on oyster supplies from other regions. In response to the industry problems, the Virginia Marine Resources Commission (VMRC) developed and began implementing an Oyster Fishery Management Plan (OFMP) in 1985. Primarily, the plan seeks to increase Virginia oyster production from both public and leased grounds. A large increase in production could significantly affect the oyster market. There is thus a need to understand the Virginia oyster market, which derives raw material supplies primarily from public and leased-grounds production and from other …


Movements And Behavior Of Wild And Head-Started Sea Turtles, John A. Keinath Jan 1993

Movements And Behavior Of Wild And Head-Started Sea Turtles, John A. Keinath

Dissertations, Theses, and Masters Projects

Flipper-tagging, aerial surveys, and satellite telemetry was used to investigate the occurrence, migratory routes, distances traveled, swimming speeds, diving behavior, and the relation of water temperature to movements and timing of migration of wild loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) sea turtles. The behavior and movements of head-started loggerhead turtles was investigated with satellite telemetry and compared to wild turtles. Flipper-tagged loggerhead and Kemp's ridley turtles inhabit Chesapeake Bay during the warm months and many return in subsequent seasons. Aerial surveys showed that loggerhead turtles migrate from south of Cape Hatteras to northern waters during May and June, …


A Model Study Of Hydrodynamic And Water Quality Characteristics Of The Rappahannock Estuary, Virginia, Kyeong Park Jan 1993

A Model Study Of Hydrodynamic And Water Quality Characteristics Of The Rappahannock Estuary, Virginia, Kyeong Park

Dissertations, Theses, and Masters Projects

A laterally integrated, two-dimensional, real-time model, consisting of linked hydrodynamic and water quality models, is developed and applied to the Rappahannock Estuary, Virginia. The hydrodynamic model, based on the principles of conservation of volume, momentum and mass, predicts surface elevation, current velocity and salinity. The water quality model, based on the conservation of mass alone, predicts eight parameters; dissolved oxygen (DO), chlorophyll 'a', carbonaceous biochemical oxygen demand (CBOD), organic nitrogen, ammonia nitrogen, nitrite-nitrate nitrogen, organic phosphorus and inorganic phosphorus. The model equations were solved using a two time level, finite difference scheme. The hydrodynamic model was calibrated and verified using …


Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri Jan 1993

Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri

Dissertations, Theses, and Masters Projects

Otoliths, scales, dorsal spines, and pectoral fin rays, of Atlantic croaker, Micropogonias undulatus, were compared for legibility of presumed annuli and precision in repeated readings, to determine the best structure for ageing. Marks on transverse otolith sections were easiest to read and showed the best agreement between readings. Fish collected in Chesapeake Bay and in Virginia and North Carolina coastal waters during 1988-1991 were then aged using otolith sections. Ages 1-8 were recorded, but eight-year-old fish were rare. Marginal increment analysis showed that for ages 1-7 annuli are formed once a year during the period April-May. Otolith age readings were …


Effects Of The Habitat And Size-Specific Predation On The Ontogenetic Shift In Habitat Use By Newly Settled Blue Crabs, Callinectes Sapidus, Adele J. Pile Jan 1993

Effects Of The Habitat And Size-Specific Predation On The Ontogenetic Shift In Habitat Use By Newly Settled Blue Crabs, Callinectes Sapidus, Adele J. Pile

Dissertations, Theses, and Masters Projects

No abstract provided.


Comparison Of Uptake And Disposition Of Organic Pollutants In Intermolt And Ecdysial Blue Crabs, Callinectes Sapidus, Judy Lynne Haner Jan 1993

Comparison Of Uptake And Disposition Of Organic Pollutants In Intermolt And Ecdysial Blue Crabs, Callinectes Sapidus, Judy Lynne Haner

Dissertations, Theses, and Masters Projects

No abstract provided.


Amorphometric And Meristic Study Of The Halfbeak, Hyporhamphus Unifasciatus (Teleostei: Hemiramphidae) From The Western Atlantic, With The Description Of A New Species, Heidi M. Banford Jan 1993

Amorphometric And Meristic Study Of The Halfbeak, Hyporhamphus Unifasciatus (Teleostei: Hemiramphidae) From The Western Atlantic, With The Description Of A New Species, Heidi M. Banford

Dissertations, Theses, and Masters Projects

No abstract provided.


The Relationship Between Dominant Macrobenthos And Cyclical Hypoxia In The Lower York River, R. Joseph Neubauer Jan 1993

The Relationship Between Dominant Macrobenthos And Cyclical Hypoxia In The Lower York River, R. Joseph Neubauer

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.


Molecular Diffusion Coefficients For Polycyclic Aromatic Hydrocarbons In Air And Water, Kurt E. Gustafson Jan 1993

Molecular Diffusion Coefficients For Polycyclic Aromatic Hydrocarbons In Air And Water, Kurt E. Gustafson

Dissertations, Theses, and Masters Projects

No abstract provided.


Distribution Of Organochlorine Pollutants In Sea Turtles, Mary J. Rybitski Jan 1993

Distribution Of Organochlorine Pollutants In Sea Turtles, Mary J. Rybitski

Dissertations, Theses, and Masters Projects

No abstract provided.


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 …


An Integration Of Case-Based And Model-Based Reasoning And Its Application To Physical System Faults, Stamos T. Karamouzis Jan 1993

An Integration Of Case-Based And Model-Based Reasoning And Its Application To Physical System Faults, Stamos T. Karamouzis

Dissertations, Theses, and Masters Projects

Case-Based Reasoning (CBR) systems solve new problems by finding stored instances of problems similar to the current one, and by adapting previous solutions to fit the current problem, taking into consideration any differences between the current and previous situations. CBR has been proposed as a more robust and plausible model of expert reasoning than the better-known rule-based systems.;Current CBR systems have been used in planning, engineering design, and memory organization. There has been minimal work, however, in the area of reasoning about physical systems. This type of reasoning is a difficult task, and every attempt to automate the process must …


Fourier Analysis Of Frequency Domain Discrete Event Simulation Experiments, Mousumi Mitra Hazra Jan 1993

Fourier Analysis Of Frequency Domain Discrete Event Simulation Experiments, Mousumi Mitra Hazra

Dissertations, Theses, and Masters Projects

Frequency Domain Experiments (FDEs) were first used in discrete-event simulation to perform system parameter sensitivity analysis for factor screening in stochastic system simulations. FDEs are based on the intuitive assertion that if one or more system parameters are oscillated at fixed frequencies throughout a simulation run, then oscillations at the same frequencies will be induced in the system's response. Spectral (Fourier) analysis of these induced oscillations is then used to characterize and analyze the system. Since their introduction 12 years ago, significant work has been done to extend the applicability of FDEs to regression analysis, simulation optimization and gradient estimation. …


The Effects Of Granularity On The Microwave Surface Impedance Of High Kappa Superconductors, Stephen Keith Remillard Jan 1993

The Effects Of Granularity On The Microwave Surface Impedance Of High Kappa Superconductors, Stephen Keith Remillard

Dissertations, Theses, and Masters Projects

The microwave surface impedance of granular high temperature superconductors is an important figure of merit for technological applications. Because the behavior of the granular materials deviates significantly from that of the ideal defect free superconductors, the loss mechanisms are not fully understood. This dissertation seeks to quantify the contribution of granularity to centimeter wave and millimeter wave losses. By understanding these losses, the superconductive coupling between neighboring grains can also be understood.;The weakly coupled grain model is used as a phenomenological description of the microwave surface impedance. The granular superconducting surface is modelled as an effective resistively shunted Josephson junction. …


The Oxidation Of Beta-Cyclodextrin Via The Photolysis Of 6-Beta-Cyclodextrin Benzoyl Formate, Heather Alison Creswick Jan 1993

The Oxidation Of Beta-Cyclodextrin Via The Photolysis Of 6-Beta-Cyclodextrin Benzoyl Formate, Heather Alison Creswick

Dissertations, Theses, and Masters Projects

No abstract provided.


The Synthesis Of N,N-Disubstituted Hydroxylamines Via Rearrangement Reactions Between Trialkylboranes And Nitrones, Stacie M. Cook Jan 1993

The Synthesis Of N,N-Disubstituted Hydroxylamines Via Rearrangement Reactions Between Trialkylboranes And Nitrones, Stacie M. Cook

Dissertations, Theses, and Masters Projects

No abstract provided.


Characterization Of Epoxy Resins For Use In The Resin Transfer Molding Process, Christina Kaye Short Jan 1993

Characterization Of Epoxy Resins For Use In The Resin Transfer Molding Process, Christina Kaye Short

Dissertations, Theses, and Masters Projects

No abstract provided.


Synthesis Of Boron-Substituted Isoxazolidines By Reaction Of Nitrones With Alkenyl Boronate Esters, Kevin P. Gwaltney Jan 1993

Synthesis Of Boron-Substituted Isoxazolidines By Reaction Of Nitrones With Alkenyl Boronate Esters, Kevin P. Gwaltney

Dissertations, Theses, and Masters Projects

No abstract provided.


Participation Of Alkenylboronate Esters In [2+2] Enone-Olefin Photocycloadditions, William Charles Lappenbusch Jan 1993

Participation Of Alkenylboronate Esters In [2+2] Enone-Olefin Photocycloadditions, William Charles Lappenbusch

Dissertations, Theses, and Masters Projects

No abstract provided.


The Synthesis Of Acetylisophthalic Acid For The Double Capping Of Beta-Cyclodextrin, Shuci Sharma Jan 1993

The Synthesis Of Acetylisophthalic Acid For The Double Capping Of Beta-Cyclodextrin, Shuci Sharma

Dissertations, Theses, and Masters Projects

No abstract provided.


Suspended Sediment Concentration Profiles In The Bottom Boundary Layer, Jingping Xu Jan 1993

Suspended Sediment Concentration Profiles In The Bottom Boundary Layer, Jingping Xu

Dissertations, Theses, and Masters Projects

Near-bottom suspended sediment concentrations and velocities were measured on the inner shelf off Duck, N.C. from late October to early November, 1991. This period embraced both fair and storm conditions. Four bottom roughness models are tested using field data together with a wave-current boundary layer model. Bottom roughness plays a significant role in calculations of sediment concentration profiles and current velocity profiles. The importance of each of the three parts in the roughness models (grain roughness, ripple roughness, and sediment motion roughness) vary depending on forcing conditions. A new bottom roughness model is established and tested. The calculated concentration and …


Code Generation Using A Backtracking Lr Parser, Laurie Anne Smith King Jan 1992

Code Generation Using A Backtracking Lr Parser, Laurie Anne Smith King

Dissertations, Theses, and Masters Projects

Although the parsing phase of the modern compiler has been automated in a machine independent fashion, the diversity of computer architectures inhibits automating the code generation phase. During code generation, some intermediate representation of a source program is transformed into actual machine instructions. The need for portable compilers has driven research towards the automatic generation of code generators.;This research investigates the use of a backtracking LR parser that treats code generation as a series of tree transformations.


Allozyme Analysis Of Billfish Population Structure, Lee W. Morgan Jan 1992

Allozyme Analysis Of Billfish Population Structure, Lee W. Morgan

Dissertations, Theses, and Masters Projects

No abstract provided.


Survival And Abundance Of Juvenile Caribbean Spiny Lobster: Effects Of Shelter Size And Geographic Location, Jonathon Daniel Mintz Jan 1992

Survival And Abundance Of Juvenile Caribbean Spiny Lobster: Effects Of Shelter Size And Geographic Location, Jonathon Daniel Mintz

Dissertations, Theses, and Masters Projects

No abstract provided.


Generic Identification And Patterns Of External Pigment In Larval Gobies (Pisces: Gobiidae) From The Belize Barrier Reef, Elizabeth D. Maddox Jan 1992

Generic Identification And Patterns Of External Pigment In Larval Gobies (Pisces: Gobiidae) From The Belize Barrier Reef, Elizabeth D. Maddox

Dissertations, Theses, and Masters Projects

No abstract provided.


Shoreline Habitat Selection By Bald Eagles (Haliaeetus Leucocephalus) In A Non-Breeding Eagle Concentration-Area On The James River, Virginia, Kennedy H. Clark Jan 1992

Shoreline Habitat Selection By Bald Eagles (Haliaeetus Leucocephalus) In A Non-Breeding Eagle Concentration-Area On The James River, Virginia, Kennedy H. Clark

Dissertations, Theses, and Masters Projects

No abstract provided.


Intelligent Processing Of Pmr-15, Sean Michael Hart Jan 1992

Intelligent Processing Of Pmr-15, Sean Michael Hart

Dissertations, Theses, and Masters Projects

No abstract provided.


Distribution, Abundance, And Behavior Of The Cownose Ray, Rhinoptera Bonasus (Mitchill 1815), In Lower Chesapeake Bay, Robert A. Blaylock Jan 1992

Distribution, Abundance, And Behavior Of The Cownose Ray, Rhinoptera Bonasus (Mitchill 1815), In Lower Chesapeake Bay, Robert A. Blaylock

Dissertations, Theses, and Masters Projects

Aspects of the ecology of the cownose ray, Rhinoptera bonasus, in the lower Chesapeake Bay and its tributaries were studied using aerial surveys, biotelemetry, and examination of stomach contents. The Chesapeake Bay was surveyed by airplane during 1986-1989, to examine the distribution of cownose rays and estimate their abundance using line transect methods. Cownose rays resided in Chesapeake Bay throughout the summer months, entering in early June and emigrating in late September. They were usually absent, or nearly so, by late October. Mean monthly abundance ranged from none present in May and November, to a September average of 9.3 &\cdot& …


A Comparison Of Grow-Out Methods For The Bay Scallop, Argopecten Irradians Irradians, At Two Sites In Virginia, Mark J. Brotman Jan 1992

A Comparison Of Grow-Out Methods For The Bay Scallop, Argopecten Irradians Irradians, At Two Sites In Virginia, Mark J. Brotman

Dissertations, Theses, and Masters Projects

No abstract provided.