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Articles 1 - 30 of 39
Full-Text Articles in Physical Sciences and Mathematics
Distribution Of Organochlorine Pollutants In Sea Turtles, Mary J. Rybitski
Distribution Of Organochlorine Pollutants In Sea Turtles, Mary J. Rybitski
Dissertations, Theses, and Masters Projects
No abstract provided.
Molecular Diffusion Coefficients For Polycyclic Aromatic Hydrocarbons In Air And Water, Kurt E. Gustafson
Molecular Diffusion Coefficients For Polycyclic Aromatic Hydrocarbons In Air And Water, Kurt E. Gustafson
Dissertations, Theses, and Masters Projects
No abstract provided.
Boundary Layer Structure In Homogeneous Tidal Flows: A Theoretical And Numerical Study, Jian Shen
Boundary Layer Structure In Homogeneous Tidal Flows: A Theoretical And Numerical Study, Jian Shen
Dissertations, Theses, and Masters Projects
No abstract provided.
The Dynamics Of An Oligohaline, Macrofaunal, Fouling Community, Michelle Lynne Thompson Neubauer
The Dynamics Of An Oligohaline, Macrofaunal, Fouling Community, Michelle Lynne Thompson Neubauer
Dissertations, Theses, and Masters Projects
No abstract provided.
Growth Response Of Eelgrass (Zostera Marina L) To Root-Rhizome And Whole Plant Exposure To Atrazine, Arthur C. Schwarzschild
Growth Response Of Eelgrass (Zostera Marina L) To Root-Rhizome And Whole Plant Exposure To Atrazine, Arthur C. Schwarzschild
Dissertations, Theses, and Masters Projects
No abstract provided.
Synthesis Of Boron-Substituted Isoxazolidines By Reaction Of Nitrones With Alkenyl Boronate Esters, Kevin P. Gwaltney
Synthesis Of Boron-Substituted Isoxazolidines By Reaction Of Nitrones With Alkenyl Boronate Esters, Kevin P. Gwaltney
Dissertations, Theses, and Masters Projects
No abstract provided.
End-To-End Analysis Of Hexagonal Vs Rectangular Sampling In Digital Imaging Systems, John Clifton Burton Ii
End-To-End Analysis Of Hexagonal Vs Rectangular Sampling In Digital Imaging Systems, John Clifton Burton Ii
Dissertations, Theses, and Masters Projects
The purpose of this study was to compare two common methods for image sampling in digital image processing: hexagonal sampling and rectangular sampling. The two methods differ primarily in the arrangement of the sample points on the image focal plane. In order to quantitatively compare the two sampling methods, a mathematical model of an idealized digital imaging system was used to develop a set of mean-squared-error fidelity loss metrics. The noiseless continuous/discrete/continuous end-to-end digital imaging system model consisted of four independent components: an input scene, an image formation point spread function, a sampling function, and a reconstruction function. The metrics …
Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri
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 …
A Model Study Of Hydrodynamic And Water Quality Characteristics Of The Rappahannock Estuary, Virginia, Kyeong Park
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 …
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
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
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.
The Oxidation Of Beta-Cyclodextrin Via The Photolysis Of 6-Beta-Cyclodextrin Benzoyl Formate, Heather Alison Creswick
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 Acetylisophthalic Acid For The Double Capping Of Beta-Cyclodextrin, Shuci Sharma
The Synthesis Of Acetylisophthalic Acid For The Double Capping Of Beta-Cyclodextrin, Shuci Sharma
Dissertations, Theses, and Masters Projects
No abstract provided.
Dielectric Relaxation In Controlled Pore Glass, David Brian Faddis
Dielectric Relaxation In Controlled Pore Glass, David Brian Faddis
Dissertations, Theses, and Masters Projects
No abstract provided.
The Structure Of The Holocephalan Head And The Relationships Of The Chondrichthyes, Eileen D. Grogan
The Structure Of The Holocephalan Head And The Relationships Of The Chondrichthyes, Eileen D. Grogan
Dissertations, Theses, and Masters Projects
The interrelationship of the chondrichthyan subclasses is evaluated based on divergence in the nature of the suspensorium, the preorbital cranial anatomy, the distribution of major venous sinuses and localization of hematopoietic tissue. The anatomy of representative extant taxa was examined by radiography and/or dissection. Fossil selachians, paraselachians, and holocephalans of the Bear Gulch of Montana, U.S.A. (Mississippian, Namurian E2B) were studied for evidence of vascular pigmentation, suspensorium, and cranial, branchial, and pectoral anatomy. These studies validate the suspensorial condition of autodiastyly and suggest autodiastyly is a fundamental condition involved in the basic radiation of Chondrichthyes. The plesiomorphous condition of all …
Gill Surface Area In Relation To Growth Rates And Maximum Size In Sharks, David Noboru Hata
Gill Surface Area In Relation To Growth Rates And Maximum Size In Sharks, David Noboru Hata
Dissertations, Theses, and Masters Projects
The most commonly used equation to describe size at age in fishes is the von Bertalanffy equation (VBE), which assumes that growth rate is based on the balance of anabolic and catabolic processes: dW/dt = HW&\sp{lcub}\rm d{rcub}&-kW&\sp{lcub}\rm m{rcub}&. Anabolism, HW&\sp{lcub}\rm d{rcub}&, is considered proportional to gill surface area (A = rW&\sp{lcub}\rm d{rcub}&), and a "generalized" VBE (GVBE) has been previously determined: L&\sb{lcub}\rm t{rcub}& = L&\sb\infty&(1-exp(-KD(t-t&\sb{lcub}\rm O{rcub})))\sp{lcub}\rm 1/D{rcub}&, where D = b-bd and b is from W = qL&\sp{lcub}\rm b{rcub}&. The growth rate may be rewritten in terms of gill area, A, as dW/dt = kA/(A&\sb\infty&/W&\sb\infty\sp{lcub}\rm m{rcub}&)-kW&\sp{lcub}\rm m{rcub}&. Gill areas were …
Suspended Sediment Concentration Profiles In The Bottom Boundary Layer, Jingping Xu
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 …
A Measurement Of The Branching Ratio Of Long-Lived Neutral Kaon Going To Positive Muon Negative Muon, Michael Thomas Witkowski
A Measurement Of The Branching Ratio Of Long-Lived Neutral Kaon Going To Positive Muon Negative Muon, Michael Thomas Witkowski
Dissertations, Theses, and Masters Projects
The branching ratio $B(K\sbsp{L}{0} \to \mu\sp+\mu\sp-)$ has been measured using data obtained during running periods in 1988, 1989 and 1990. The data obtained in the 1990 running period are the latest and last from BNL experiment E791. During the three running periods, 87, 274 and 346 respective candidate events were observed, forming an overall sample of 707 $\mu\sp+\mu\sp-$ events. This number represents the largest sample to-date of $K\sbsp{L}{0} \to \mu\sp+\mu\sp-$ events. The result for the branching fraction using the total data set is $B(K\sbsp{L}{0} \to \mu\sp+\mu\sp-)$ = (6.86 $\pm$ 0.37) $\times$ 10$\sp{-9}$. This result is very near the unitarity bound …
An Integration Of Case-Based And Model-Based Reasoning And Its Application To Physical System Faults, Stamos T. Karamouzis
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
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
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. …
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 …
Characterization Of Epoxy Resins For Use In The Resin Transfer Molding Process, Christina Kaye Short
Characterization Of Epoxy Resins For Use In The Resin Transfer Molding Process, Christina Kaye Short
Dissertations, Theses, and Masters Projects
No abstract provided.
A Study Of The Guiding Center Approximation, Qun Yao
A Study Of The Guiding Center Approximation, Qun Yao
Dissertations, Theses, and Masters Projects
A Hamiltonian treatment for the motion of a charged particle in a toroidal magnetic field is given. Assuming the plasma equilibrium, Boozer coordinates are used. The Hamiltonian of the exact trajectory is given in the guiding center coordinates. The higher order corrections to the standard drift Hamiltonian are derived. It is shown that the exact Hamiltonian depends on both the field strength and the shape of the magnetic surfaces (the metric of Boozer coordinates) while the standard drift Hamiltonian depends only on the field strength. The first order correction to the standard drift Hamiltonian, in gyroradius to system size, depends …
Beyond The Standard Model: New Scalars And New Leptons, Yao Yuan
Beyond The Standard Model: New Scalars And New Leptons, Yao Yuan
Dissertations, Theses, and Masters Projects
Physics that might lie beyond the standard model is discussed, with special emphasis on two possible extensions of the standard model: multi-Higgs extension, and the fourth generation leptons.;In multi-Higgs-boson extensions of the standard model, tree-level flavor-changing neutral currents exist naturally. It is often believed that the presence of the tree-level FCNC in this model is fatal, unless a discrete symmetry is added, since it requires the exchanged scalar to be extremely heavy. This follows, however, from the assumption that the flavor-changing coupling is quite large. Using a more natural value for the flavor-changing coupling, much smaller bounds were obtained. Unlike …
A Study Of Molecular Order And Motion In Nematic Liquid Crystal Mixtures, Jon Michael Goetz
A Study Of Molecular Order And Motion In Nematic Liquid Crystal Mixtures, Jon Michael Goetz
Dissertations, Theses, and Masters Projects
Materials which flow like fluids, but possess anisotropic properties like molecular crystals, are called 'liquid crystals'. Studies of liquid crystals contribute to our understanding of how molecular orientation influences macroscopic properties. This thesis presents experimental and theoretical investigations of molecular order and dynamics in nematic liquid crystal systems. First, deuterium nuclear magnetic resonance is used to determine the degree of orientational order of both components of a liquid crystal mixture simultaneously. The temperature dependence of the four order parameters is interpreted using a newly developed mean field theory of nematic binary mixtures composed of biaxial molecules. Next, mean field theory …
Photoabsorption Spectra Of Hydrogen In Magnetic Fields, John A. Shaw
Photoabsorption Spectra Of Hydrogen In Magnetic Fields, John A. Shaw
Dissertations, Theses, and Masters Projects
Measurements of the absorption spectrum of atomic H in strong magnetic fields have been analyzed. The measurements, performed by the Bielefeld, Germany experimental group, investigated the photoabsorption to levels near the ionization threshold in magnetic fields ranging from 2.7 to 6 Tesla. Taking advantage of a classical scaling law, the photon energy and the magnetic field strength were varied simultaneously in the experiment and the absorption rate vs. B{dollar}\sp{lcub}-1/3{rcub}{dollar} at fixed scaled-energy, {dollar}\varepsilon{dollar} = E/(B/B{dollar}\sb{lcub}\rm o{rcub})\sp{lcub}2/3{rcub}{dollar} was measured. The absorption rate was observed to exhibit sinusoidal fluctuations which we correlate with closed classical orbit of the electron. A Fourier transformation …
Flush Communication Channels: Effective Implementation And Verification, Tracy Kay Camp
Flush Communication Channels: Effective Implementation And Verification, Tracy Kay Camp
Dissertations, Theses, and Masters Projects
Flush communication channels, or F-channels, generalize more conventional asynchronous communication paradigms. A distributed system which uses an F-channel allows a programmer to define the delivery order of each message in relation to other messages transmitted on the channel. Unreliable datagrams and FIFO (first-in-first-out) communication channels have strictly defined delivery semantics. No restrictions are allowed on message delivery order with unreliable datagrams--message delivery is completely unordered. FIFO channels, on the other hand, insist messages are delivered in the order of their transmission. Flush channels can provide either of these delivery order semantics; in addition, F-channels allow the user to define the …
Movements And Behavior Of Wild And Head-Started Sea Turtles, John A. Keinath
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, …