Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Dissertations, Theses, and Masters Projects

Discipline
Keyword
Publication Year

Articles 991 - 1020 of 1876

Full-Text Articles in Physical Sciences and Mathematics

Diet Composition And Feeding Habits Of Large Striped Bass, Morone Saxatilis, In Chesapeake Bay, John F. Walter Jan 1999

Diet Composition And Feeding Habits Of Large Striped Bass, Morone Saxatilis, In Chesapeake Bay, John F. Walter

Dissertations, Theses, and Masters Projects

No abstract provided.


Indo-Pacific Population Structure Of The Black Marlin, Makaira Indica, Inferred From Molecular Markers, Brett Falterman Jan 1999

Indo-Pacific Population Structure Of The Black Marlin, Makaira Indica, Inferred From Molecular Markers, Brett Falterman

Dissertations, Theses, and Masters Projects

No abstract provided.


Limits To Parallelism In Scientific Computing, Dan Alvin Chrisman Jr. Jan 1999

Limits To Parallelism In Scientific Computing, Dan Alvin Chrisman Jr.

Dissertations, Theses, and Masters Projects

The goal of our research is to decrease the execution time of scientific computing applications. We exploit the application's inherent parallelism to achieve this goal. This exploitation is expensive as we analyze sequential applications and port them to parallel computers. Many scientifically computational problems appear to have considerable exploitable parallelism; however, upon implementing a parallel solution on a parallel computer, limits to the parallelism are encountered. Unfortunately, many of these limits are characteristic of a specific parallel computer. This thesis explores these limits.;We study the feasibility of exploiting the inherent parallelism of four NASA scientific computing applications. We use simple …


Accurate Visualization Of Distributed System Execution, Dennis Lee Edwards Jan 1999

Accurate Visualization Of Distributed System Execution, Dennis Lee Edwards

Dissertations, Theses, and Masters Projects

The concurrent execution of processes in a distributed system makes the interactions between them difficult to understand. A clear image of the execution sequence that occurs as well as possible alternative scenarios is paramount to providing the software engineer the understanding needed to create reliable software.;In this thesis, we examine several representation methods of presenting a pictorial view of the execution of a distributed system and evaluate each in terms of three criteria. First, only those relationships that are created during the execution can and must be presented. Second, the presentation must be such that a reasonable amount of information …


Characterization Of The Physical Properties Of Iron Polyimide Nanocomposites, Russell A. Wincheski Jan 1999

Characterization Of The Physical Properties Of Iron Polyimide Nanocomposites, Russell A. Wincheski

Dissertations, Theses, and Masters Projects

The discovery of tunneling magneto-resistance has led to a great deal of interest in the study of ferromagnet-insulator-ferromagnet (FIF) systems due to potential sensor and magnetic storage applications. An analysis of the band structure of the 3d ferromagnets shows that the conduction electrons become spin polarized by the molecular field. The transmission coefficient of these electrons across a tunneling gap therefore depends upon the relative alignment of the molecular field between the two ferromagnets.;In this work the manufacture of such tunneling gaps through compression molding of powdered ferromagnetic iron with a high performance polyimide has been studied for the first …


Dynamic Load Balancing Via Thread Migration, David Cronk Jan 1999

Dynamic Load Balancing Via Thread Migration, David Cronk

Dissertations, Theses, and Masters Projects

Light-weight threads are becoming increasingly useful for parallel processing. This is particularly true for threads running in a distributed memory environment. Light-weight threads can be used to support latency hiding techniques, communication and computation overlap, and functional parallelism. Additionally, dynamic migration of light-weight threads supports both data locality and load balancing. Designing a thread migration mechanism presents some very unique and interesting challenges. One such challenge is maintaining communication between mobile threads. A potentially more difficult challenge involves maintaining the correctness of pointers within mobile threads. Since traditional pointers have no concept of address space, moving threads from processor to …


Turbulence In Binary Fluid Flow Systems: A Lattice Boltzmann Approach, Darren M. Wah Jan 1999

Turbulence In Binary Fluid Flow Systems: A Lattice Boltzmann Approach, Darren M. Wah

Dissertations, Theses, and Masters Projects

A method for simulating a turbulent binary fluid flow system based on the Lattice Boltzmann Method (LBM) is presented. The fluid equations up to the Navier-Stokes transport level are derived for this two fluid system, and results from numerical simulations using this method are shown. Finally, grid resolution is performed in a single fluid (LBM) simulation which determines the largest valid mesh size for a simulation that seeks to resolve physical structures of all scales.


Causal Distributed Assert Statements, Sharon J. Simmons Jan 1999

Causal Distributed Assert Statements, Sharon J. Simmons

Dissertations, Theses, and Masters Projects

Monitoring a program's execution is fundamental to the debugging, testing and maintenance phases of program development. This research addresses the issue of monitoring the execution of a distributed program. In particular, we are concerned with efficient techniques for evaluating global state predicates for distributed programs. The global state of a distributed program is not well-defined, making the monitoring task complex compared to that of a sequential programs. Processes of a distributed program execute concurrently, and the events of the program cannot be totally ordered. Each process has its own local memory, and the local memories are physically separate.;Despite the difficulties …


Thermoelastic And Photoelastic Full-Field Stress Measurement, Deonna Faye Woolard Jan 1999

Thermoelastic And Photoelastic Full-Field Stress Measurement, Deonna Faye Woolard

Dissertations, Theses, and Masters Projects

Photoelasticity is an optical technique that measures the difference of the principal stresses plus the principal stress direction. A complementary technique is thermoelasticity which measures the sum of the principal stresses. Combining these two full-field, non-contact nondestructive evaluation techniques allows the individual stress components to be measured. One of the main difficulties in merging these two measurement systems is in identifying an appropriate surface coating. Thermoelasticity demands a highly emissive surface, while photoelasticity requires a thick, stress-birefringent, transparent coating with a retro-reflective backing. Two coatings have been identified that can be used for combined thermoelastic and photoelastic stress measurements: PMMA …


Reproductive Success Of Black Skimmers On An Artificial Island: Effects Of Hatching Date And Feeding Rate, Christopher Alan Gordon Jan 1999

Reproductive Success Of Black Skimmers On An Artificial Island: Effects Of Hatching Date And Feeding Rate, Christopher Alan Gordon

Dissertations, Theses, and Masters Projects

No abstract provided.


Additives For Increased Atomic Oxygen Resistance In Cyanate Ester Resins, Sandeep Amar Saggar Jan 1999

Additives For Increased Atomic Oxygen Resistance In Cyanate Ester Resins, Sandeep Amar Saggar

Dissertations, Theses, and Masters Projects

No abstract provided.


Artificial Societies: A Computational Model Of Disease Transmission, Nathan T. Moore Jan 1999

Artificial Societies: A Computational Model Of Disease Transmission, Nathan T. Moore

Dissertations, Theses, and Masters Projects

No abstract provided.


Carbon Cycling In The York River Estuary: An Isotopic And Mass Balance Approach Using Natural Carbon-14 And Carbon-18 Isotopes, Donald W. Linebaugh Jan 1999

Carbon Cycling In The York River Estuary: An Isotopic And Mass Balance Approach Using Natural Carbon-14 And Carbon-18 Isotopes, Donald W. Linebaugh

Dissertations, Theses, and Masters Projects

No abstract provided.


Chemical Interaction Of "Declorane Plus" With Antimony Trioxide In Nylon 66, Yum Min Kang Jan 1998

Chemical Interaction Of "Declorane Plus" With Antimony Trioxide In Nylon 66, Yum Min Kang

Dissertations, Theses, and Masters Projects

No abstract provided.


A Framework For Planning Sustainable Development In Coastal Regions: An Island Pilot Project In Croatia, Anamarija Frankic Jan 1998

A Framework For Planning Sustainable Development In Coastal Regions: An Island Pilot Project In Croatia, Anamarija Frankic

Dissertations, Theses, and Masters Projects

There have been few empirical studies demonstrating how sustainable development has been realized in a specific regime. This project developed and tested a framework for comprehensive planning including environmental, social, and economic considerations on the island Cres in the Croatian Coastal Zone. The approach defines sustainable development in coastal regions, and develops a generic framework incorporating biological, geological, chemical, physical, social, and economic factors necessary for sustainable development. The generic framework ensures that planning decisions will be based on environmental concerns of the area. A prime principle of the approach is that any plan must work with the environmental limits …


Distribution, Partitioning And Fluxes Of Dissolved And Particulate Organic Carbon, Nitrogen And Phosphorus In The Eastern North Pacific And Southern Oceans, Ai Ning Loh Jan 1998

Distribution, Partitioning And Fluxes Of Dissolved And Particulate Organic Carbon, Nitrogen And Phosphorus In The Eastern North Pacific And Southern Oceans, Ai Ning Loh

Dissertations, Theses, and Masters Projects

No abstract provided.


Calcium As A Limiting Factor In The Distribution Of The Amphipod Gammarus Pseudolimnaeus, John Kinsley Zehmer Jan 1998

Calcium As A Limiting Factor In The Distribution Of The Amphipod Gammarus Pseudolimnaeus, John Kinsley Zehmer

Dissertations, Theses, and Masters Projects

No abstract provided.


Selective Selenoxide Elimination On The Secondary Face Of Beta-Cyclodextrin, Ahmed M. Hafez Jan 1998

Selective Selenoxide Elimination On The Secondary Face Of Beta-Cyclodextrin, Ahmed M. Hafez

Dissertations, Theses, and Masters Projects

No abstract provided.


Searches For Exotic Matter, David Lee Morgan Jan 1998

Searches For Exotic Matter, David Lee Morgan

Dissertations, Theses, and Masters Projects

This research encompasses two quite distinct searches for exotic matter. The first half concerns exotic matter on the scale of elementary particles. In this chapter, I consider the production of gluinos, the supersymmetric partner of the gluon, in models where the gluino is very light. Cross sections are calculated for electroproduction and hadroproduction of gluinos and the results indicate that existing accelerators are capable of probing the region of gluino masses between 1.0 and 2.0GeV with lifetimes between 10{dollar}\sp{lcub}-10{rcub}{dollar} and 10{dollar}\sp{lcub}-6{rcub}{dollar} seconds. Such experiments could find a light gluino if it exists, or to close this unexplored mass-lifetime window. The …


Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers Jan 1998

Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers

Dissertations, Theses, and Masters Projects

No abstract provided.


Development Of A Quantitative Competetive Polymerase Chain Reaction Assay For The Detection And Quantitation Of Perkinsus Marinus In Oyster Tissues And Environmental Water Samples, Heather A. Yarnall Jan 1998

Development Of A Quantitative Competetive Polymerase Chain Reaction Assay For The Detection And Quantitation Of Perkinsus Marinus In Oyster Tissues And Environmental Water Samples, Heather A. Yarnall

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effects Of Increased Inundation And Wrack Deposition On Photosynthesis And Respiration In A Virginia Salt Marsh, W. David Miller Jan 1998

The Effects Of Increased Inundation And Wrack Deposition On Photosynthesis And Respiration In A Virginia Salt Marsh, W. David Miller

Dissertations, Theses, and Masters Projects

No abstract provided.


A Study Of 3-Tropylium-1,5-Hexadiene, Elise Noma Hattersley Jan 1998

A Study Of 3-Tropylium-1,5-Hexadiene, Elise Noma Hattersley

Dissertations, Theses, and Masters Projects

No abstract provided.


The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins Jan 1998

The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins

Dissertations, Theses, and Masters Projects

No abstract provided.


Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford Jan 1998

Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford

Dissertations, Theses, and Masters Projects

Phylogenetic and historical biogeographic hypotheses were explored for three groups of teleost fishes that are hypothesized to share a common biogeographic track. Distributed across the eastern Pacific/eastern Atlantic (EP/EA) biogeographic track of Rosen (1975) are the Scomberomorus regalis (Scombridae), Strongylura marina (Belonidae) and Hyporhamphus unifasciatus (Hemiramphidae) species groups comprised of one eastern Atlantic; three, three and four western Atlantic; and two, two and four eastern Pacific species, respectively, for each group. In addition, two species in the Strongylura marina and Hyporhamphus unifasciatus groups, have invaded freshwater drainages of Central and South America. Each of the three species groups were found …


Interactive Effects Of Cadmium And Benzo(A)Pyrene In Mummichog (Fundulus Heteroclitus), Peter Van Den Hurk Jan 1998

Interactive Effects Of Cadmium And Benzo(A)Pyrene In Mummichog (Fundulus Heteroclitus), Peter Van Den Hurk

Dissertations, Theses, and Masters Projects

When animals are exposed to mixtures of environmental pollutants, it is generally assumed that the toxic effects of the individual components are additive. However, examples of synergistic and antagonistic effects have been described. to study the mechanisms of interaction between a metal and a polycyclic aromatic hydrocarbon, mummichog (Fundulus heteroclitus) were injected with combinations of cadmium (Cd) and benzo (a) pyrene (BP). Measured effect parameters were: mortality, BP-metabolite production in isolated hepatocytes and microsomes, hepatic induction of CYP1A (the BP metabolizing enzyme) and metallothionein (the Cd binding protein), and biliary excretion of BP-metabolites. The mortality data demonstrated that both synergistic …


Development And Analysis Of A Nutrient Trading Program For The James River Watershed, Jennifer M. Reid Jan 1998

Development And Analysis Of A Nutrient Trading Program For The James River Watershed, Jennifer M. Reid

Dissertations, Theses, and Masters Projects

No abstract provided.


Tagging And Habitat Utilization Of Juvenile Summer Flounder, Paralichthys Dentatus, Richard Thomas Kraus Jan 1998

Tagging And Habitat Utilization Of Juvenile Summer Flounder, Paralichthys Dentatus, Richard Thomas Kraus

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effect Of Phragmites Australis Invasion On Community Processes In A Tidal Freshwater Marsh, Michael Leadbeater Campana Jan 1998

The Effect Of Phragmites Australis Invasion On Community Processes In A Tidal Freshwater Marsh, Michael Leadbeater Campana

Dissertations, Theses, and Masters Projects

No abstract provided.


Africa As A Regional And Global Source Of Atmospheric Gases And Particulates, Lawrence Mtetwa Jan 1998

Africa As A Regional And Global Source Of Atmospheric Gases And Particulates, Lawrence Mtetwa

Dissertations, Theses, and Masters Projects

The role of the continent of Africa as a source of gaseous and particulate emissions to the atmosphere is investigated in this study. Sources of gases and particulates from Africa include fossil fuel combustion, biomass burning, and biogenic soil emissions of nitric oxide. This study represents the first comprehensive database of gaseous and particulate emissions developed for the continent of Africa on a country by country basis and establishes the framework for country-by-country, assessment of greenhouse gases emissions as required by the Kyoto Conference on Global Warming, which was attended by representatives from more than 100 countries. Calculations of gases …