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Dissertations, Theses, and Masters Projects

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Articles 1261 - 1290 of 1876

Full-Text Articles in Physical Sciences and Mathematics

Role Of Habitat Features And Chemical Cues In Substrate Selection By Blue Crab Megalopae: Evidence From Laboratory Experiments, Bruce Clare Layman Jan 1992

Role Of Habitat Features And Chemical Cues In Substrate Selection By Blue Crab Megalopae: Evidence From Laboratory Experiments, Bruce Clare Layman

Dissertations, Theses, and Masters Projects

No abstract provided.


Measurement Of The Carbon And Nitrogen Densities Of The Marine Heterotrophic Flagellate Paraphysomonas Sp, Yongsik Sin Jan 1992

Measurement Of The Carbon And Nitrogen Densities Of The Marine Heterotrophic Flagellate Paraphysomonas Sp, Yongsik Sin

Dissertations, Theses, and Masters Projects

No abstract provided.


Land Use And Wetland Function: A Sensitivity Analysis Of The Vims Nontidal Wetland Functional Assessment Method, Martha Craig Jan 1992

Land Use And Wetland Function: A Sensitivity Analysis Of The Vims Nontidal Wetland Functional Assessment Method, Martha Craig

Dissertations, Theses, and Masters Projects

No abstract provided.


The Branching Fraction Of Long-Lived Kaon Going To Muon-Anti-Muon, Michael David Chapman Jan 1992

The Branching Fraction Of Long-Lived Kaon Going To Muon-Anti-Muon, Michael David Chapman

Dissertations, Theses, and Masters Projects

This thesis presents the results of a measurement of the branching fraction of the $K\sb{L}\to\mu\bar{\mu}$ decay. This decay is scGIM supressed in the Standard Model, and provides a useful test of that model. Additionally, the degree of deviation from the unitary limit provides a useful test for several other models. The experiment was performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron facility. The apparatus consisted of a two-magnet mass spectrometer, together with dual electromagnetic and muon particle identification systems. A total of 281 $K\sb{L}\to\mu\bar{\mu}$ events were observed. Normalizing to the 15,768 $K\sb{L}\to\pi\bar{\pi}$ events observed results in a branching fraction …


Completion Of Partial Operator Matrices, M.(Mihaly) Bakonyi Jan 1992

Completion Of Partial Operator Matrices, M.(Mihaly) Bakonyi

Dissertations, Theses, and Masters Projects

This work concerns completion problems for partial operator matrices. A partial matrix is an m-by-n array in which some entries are specified and the remaining are unspecified. We allow the entries to be operators acting between corresponding vector spaces (in general, bounded linear operators between Hilbert spaces). Graphs are associated with partial matrices. Chordal graphs and directed graphs with a perfect edge elimination scheme play a key role in our considerations. A specific choice for the unspecified entries is referred to as a completion of the partial matrix. The completion problems studied here involve properties such as: zero-blocks in certain …


Formation And Desorption Of Negative Ions From Metal Surfaces, Douglas Hugh Baker Jan 1992

Formation And Desorption Of Negative Ions From Metal Surfaces, Douglas Hugh Baker

Dissertations, Theses, and Masters Projects

Investigations of negative ion and electron emission from gas-covered metal surfaces due to the impact of low energy (30-300 eV) positive ions and, separately, photons (2-5 eV) are presented. In both cases, the negative ion formation process is thought to occur via electron tunneling from the surface or its substrate to a sputtered or photodesorbed neutral atom or molecule.;In particular, absolute total negative ion and electron yields for collisions of positive alkali ions with a gas-covered Mo substrate have been measured. Mass analysis of the sputtered negative ions show that O{dollar}\sb2\sp-{dollar} is the dominant ion at low impact energies. This …


Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr Jan 1992

Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr

Dissertations, Theses, and Masters Projects

In this dissertation, I experimentally examine predation-induced mortality upon juvenile queen conch, Strombus gigas, and assess the importance of select habitat predator and conch characteristics affecting predation intensity. Experiments were conducted during the summer and early fall of 1987, 1988, 1990 and 1991 in seagrass beds and adjacent sand flats near Lee Stocking Island, Exuma Cays, Bahamas. These experiments indicate that various factors act interactively to produce habitat-specific mortality rates in queen conch due to predation. These include (1) habitat type, whereby seagrass beds offer some protection; (2) local population dynamics, such that populated seagrass beds appear to enhance conch …


Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo Jan 1992

Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo

Dissertations, Theses, and Masters Projects

A model of zinc accumulation by the American oyster, Crassostrea virginica, is developed by relating in-situ zinc body burden to time-integration of uptake. Short-term uptake rates are estimated in laboratory by introducing &\sp{lcub}65{rcub}&Zn to oysters of various weights in aquaria with salinities of 18&\perthous& and 12&\perthous&. Uptake of &\sp{lcub}65{rcub}&Zn by an oyster: (1) varies as a power function of the body weight (soft tissue dry weight) of the oyster (&dy\over{lcub}dt{rcub}& = kW&\sp{lcub}\beta{rcub}&), (2) is inversely related to the salinity of ambient water, and (3) increases linearly with ambient concentration. Zinc body burdens of oysters of various weights from oyster beds …


The Effect Of A One-Meter Sea-Level Rise On Tidal Wetlands In Gloucester County, Virginia, Paula Lindsey Hill Jan 1992

The Effect Of A One-Meter Sea-Level Rise On Tidal Wetlands In Gloucester County, Virginia, Paula Lindsey Hill

Dissertations, Theses, and Masters Projects

No abstract provided.


An Investigation Of The Late Pleistocene Paleochannel Systems In The Continental Shelf, South Of Chesapeake Bay Mouth, Ziqiang Chen Jan 1992

An Investigation Of The Late Pleistocene Paleochannel Systems In The Continental Shelf, South Of Chesapeake Bay Mouth, Ziqiang Chen

Dissertations, Theses, and Masters Projects

No abstract provided.


Intentional Introductions Of Non-Indigenous Species: A Case Study Of Policy And Management Affecting Crassostrea Gigas, Gwynne D. Brown Jan 1992

Intentional Introductions Of Non-Indigenous Species: A Case Study Of Policy And Management Affecting Crassostrea Gigas, Gwynne D. Brown

Dissertations, Theses, and Masters Projects

No abstract provided.


Taxonomy Of Larval Blennioidei Of Belize, Central America, Martin Ray Cavalluzzi Jan 1992

Taxonomy Of Larval Blennioidei Of Belize, Central America, Martin Ray Cavalluzzi

Dissertations, Theses, and Masters Projects

No abstract provided.


Juvenile Pelagic Fish Communities In The Mattaponi And Pamunkey Rivers, Virginia, Steffany Dawson Jan 1992

Juvenile Pelagic Fish Communities In The Mattaponi And Pamunkey Rivers, Virginia, Steffany Dawson

Dissertations, Theses, and Masters Projects

No abstract provided.


Quasilinear Theory Of Laser-Plasma Interactions, Alastair John Neil Jan 1992

Quasilinear Theory Of Laser-Plasma Interactions, Alastair John Neil

Dissertations, Theses, and Masters Projects

The interaction of a high intensity laser beam with a plasma is generally susceptible to the filamentation instability due to nonuniformities in the laser profile. In ponderomotive filamentation high intensity spots in the beam expell plasma by ponderomotive force, lowering the local density, causing even more light to be focused into the already high intensity region. The result--the beam is broken up into a filamentary structure.;Several optical smoothing techniques have been proposed to eliminate this problem. In the Random Phase Plates (RPS) approach, the beam is split into a very fine scale, time-stationary interference pattern. The irregularities in this pattern …


Design And Analysis Techniques For Concurrent Blackboard Systems, John William Mcmanus Jan 1992

Design And Analysis Techniques For Concurrent Blackboard Systems, John William Mcmanus

Dissertations, Theses, and Masters Projects

Blackboard systems are a natural progression of Artificial Intelligence based systems into a more powerful problem solving technique. They provide a way for several highly specialized knowledge sources to cooperate to solve large, complex problems. Blackboard systems incorporate the concepts developed by rule-based and expert systems programmers and include the ability to add conventionally coded knowledge sources. The small and specialized knowledge sources are easier to develop and test, and are hosted on hardware specifically suited to the task that they are solving.;Designing and developing blackboard systems is a difficult process. The designer is attempting to balance several conflicting goals …


Painleve Singularity Analysis Applied To Charged Particle Dynamics During Reconnection, Jay Walter Larson Jan 1992

Painleve Singularity Analysis Applied To Charged Particle Dynamics During Reconnection, Jay Walter Larson

Dissertations, Theses, and Masters Projects

For a plasma in the collisionless regime, test-particle modelling can lend some insight into the macroscopic behavior of the plasma, e.g conductivity and heating. A common example for which this technique is used is a system with electric and magnetic fields given by B = {dollar}\delta y{dollar}cx x + xcx y + {dollar}\gamma{dollar}cx z and E = {dollar}\epsilon{dollar}cx z, where {dollar}\delta{dollar}, {dollar}\gamma{dollar}, and {dollar}\epsilon{dollar} are constant parameters. This model can be used to model plasma behavior near neutral lines, ({dollar}\gamma{dollar} = 0), as well as current sheets ({dollar}\gamma{dollar} = 0, {dollar}\delta{dollar} = 0). The integrability properties of the particle motion …


Synthesis And Inclusion Of 1-(5-Cyanonaphthyl) Diazomethane With B-Cyclodextrin, Scott Tobias Forrest Jan 1992

Synthesis And Inclusion Of 1-(5-Cyanonaphthyl) Diazomethane With B-Cyclodextrin, Scott Tobias Forrest

Dissertations, Theses, and Masters Projects

No abstract provided.


Verification Of Fault-Tolerant Clock Synchronization Systems, Paul S. Miner Jan 1992

Verification Of Fault-Tolerant Clock Synchronization Systems, Paul S. Miner

Dissertations, Theses, and Masters Projects

No abstract provided.


A Helium Discharge Detector For The Determination Of Organosulfur And Phosphorus Compounds, Tamara L. Tieman Jan 1992

A Helium Discharge Detector For The Determination Of Organosulfur And Phosphorus Compounds, Tamara L. Tieman

Dissertations, Theses, and Masters Projects

No abstract provided.


The Imidization Reactions Of Pmr-15 Polyimide, Kerri Ann Robillard Jan 1992

The Imidization Reactions Of Pmr-15 Polyimide, Kerri Ann Robillard

Dissertations, Theses, and Masters Projects

No abstract provided.


Gender Roles And Home Computer Use By Children, Trelles Whitfield D'Alemberte Jan 1991

Gender Roles And Home Computer Use By Children, Trelles Whitfield D'Alemberte

Dissertations, Theses, and Masters Projects

No abstract provided.


Food And Feeding Of Northern Bluefin Tuna (Thunnus Thynnus) And Yellowfin Tuna (Thunnus Albarcares): A Comparative Study Of The Food And Feeding Habits Of The Northern Bluefin Tuna Off The Coast Of Virginia, Charles Gilbert Barr Jan 1991

Food And Feeding Of Northern Bluefin Tuna (Thunnus Thynnus) And Yellowfin Tuna (Thunnus Albarcares): A Comparative Study Of The Food And Feeding Habits Of The Northern Bluefin Tuna Off The Coast Of Virginia, Charles Gilbert Barr

Dissertations, Theses, and Masters Projects

No abstract provided.


Stock Enhancement Of Caribbean Spiny Lobster, Panulirus Argus Latrielle, Using Artificial Shelters: Patterns Of Survival And Dynamics Of Shelter Selection, David Bryan Eggleston Jan 1991

Stock Enhancement Of Caribbean Spiny Lobster, Panulirus Argus Latrielle, Using Artificial Shelters: Patterns Of Survival And Dynamics Of Shelter Selection, David Bryan Eggleston

Dissertations, Theses, and Masters Projects

Field tethering experiments in seagrass beds of Bahia de la Ascension, Mexico examined the impact of different-sized artificial shelters upon survival of three juvenile size-classes of the Caribbean spiny lobster, Panulirus argus. The artificial shelters were concrete structures (casitas) that simulate lobster dens. In the tethering experiments, spiny lobster survival was generally higher in smaller than larger casitas, though the effect depended upon the relationship between lobster and shelter size. Thus, spiny lobster survival depends not only upon the availability of shelter, but also on the scaling between shelter size and lobster size. These results suggest that placement of appropriately-scaled …


Vegetation Ecology Of Tidal Freshwater Swamps Of The Lower Chesapeake Bay, United States Of America, Richard D. Rheinhardt Jan 1991

Vegetation Ecology Of Tidal Freshwater Swamps Of The Lower Chesapeake Bay, United States Of America, Richard D. Rheinhardt

Dissertations, Theses, and Masters Projects

Woody and herbaceous vegetation were sampled in 23 tidal swamps along a tidal freshwater tributary of lower Chesapeake Bay. Four vegetative categories were ordinated with Detrended Correspondence Analysis (DECORANA). Species distribution patterns of each strata were compared with respect to edaphic factors, a wetness index, and mean water table depth. Woody species are restricted to hummocks (topographic highs). Hummocks drain as quickly as the tide drops and so are partially inundated for only short periods each day. Although low in canopy diversity, tidal swamps are floristically rich in herbaceous and woody understory species, ranking them among the most speciose in …


U(1) String Tension, Arthur F. Griesser Jan 1991

U(1) String Tension, Arthur F. Griesser

Dissertations, Theses, and Masters Projects

The long distance force between quarks in the U(1) approximation to quantum chromodynamics is calculated on a home made reduced instruction set computer optimized for that purpose. It is found that previous calculations were in error by as much as 85% due to contamination by the Coulomb interaction. The Coulomb constant, measured for the first time in this work, agrees with analytically obtained values.


The Relationship Of Habitat And Spatial Scale Upon The Developmental State And Settlement Of Blue Crab Postlarvae In Chesapeake Bay, Karen S. Metcalf Jan 1991

The Relationship Of Habitat And Spatial Scale Upon The Developmental State And Settlement Of Blue Crab Postlarvae In Chesapeake Bay, Karen S. Metcalf

Dissertations, Theses, and Masters Projects

No abstract provided.


Dielectric Monitoring Of The Chemical, Rheological, And Morphological Changes Incurred During Cure Of Epoxide-Amine Systems, Dara Elyn Levy Jan 1991

Dielectric Monitoring Of The Chemical, Rheological, And Morphological Changes Incurred During Cure Of Epoxide-Amine Systems, Dara Elyn Levy

Dissertations, Theses, and Masters Projects

No abstract provided.


The Investigation Of Organoboron Compounds And Organoboron/Nitrone Reactions, David Kent Hood Jan 1991

The Investigation Of Organoboron Compounds And Organoboron/Nitrone Reactions, David Kent Hood

Dissertations, Theses, and Masters Projects

No abstract provided.


Evaluation Of Scavenger Gases In A Helium Discharge Detector, Sandra Lynn Poteat Jan 1991

Evaluation Of Scavenger Gases In A Helium Discharge Detector, Sandra Lynn Poteat

Dissertations, Theses, and Masters Projects

No abstract provided.


Preparation And Characterization Of (E)-1-Alkenylboranes And(E)-1-Alkenylboronates An Investigation Of Borane/Nitrone Reactions, Philip Louis Smith Jan 1991

Preparation And Characterization Of (E)-1-Alkenylboranes And(E)-1-Alkenylboronates An Investigation Of Borane/Nitrone Reactions, Philip Louis Smith

Dissertations, Theses, and Masters Projects

No abstract provided.