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Articles 1201 - 1230 of 1876
Full-Text Articles in Physical Sciences and Mathematics
The Role Of Predation On Zostera Marina L (Eelgrass) Seed Abundance, James Fishman
The Role Of Predation On Zostera Marina L (Eelgrass) Seed Abundance, James Fishman
Dissertations, Theses, and Masters Projects
No abstract provided.
Mitochondrial Dna Variation In Natural And Cultured Populations Of The Bay Scallop, Argopecten Irradians (Lamarck) And The Calico Scallop, Argopecten Gibbus (Dall), Sandra Grace Blake
Mitochondrial Dna Variation In Natural And Cultured Populations Of The Bay Scallop, Argopecten Irradians (Lamarck) And The Calico Scallop, Argopecten Gibbus (Dall), Sandra Grace Blake
Dissertations, Theses, and Masters Projects
No abstract provided.
Measurement Of In Situ Eelgrass Community Metabolism In Standing And Flowing Waters: Methods And Models, William James Seufzer
Measurement Of In Situ Eelgrass Community Metabolism In Standing And Flowing Waters: Methods And Models, William James Seufzer
Dissertations, Theses, and Masters Projects
No abstract provided.
Investigations Into Cataract Formation In Sciaenid Fish Species From The Elizabeth River, Chesapeake Bay, Virginia, Christopher D. Williams
Investigations Into Cataract Formation In Sciaenid Fish Species From The Elizabeth River, Chesapeake Bay, Virginia, Christopher D. Williams
Dissertations, Theses, and Masters Projects
Cataract formation in the Elizabeth River (ER) has been reported since 1986. Previous studies have concentrated on describing cataract as a function of exposure to polluted sediments, especially polycyclic aromatic hydrocarbons (PAH). These studies, however, have not examined what processes might be involved in fish cataractogenesis. The overall objective of this research was to identify important processes associated with the early development of cataract in feral fish populations. Field studies were used to systematically examine cataract development. Cataract in sciaenids was not associated with previously described cataractogenic factors, but could be linked to contaminated sediments of the ER. Cataract was …
Polarization Transfer Coefficient Measurements In The Deuteron Breakup Reaction Hydrogen-1(Polarized Deuteron,Polarized Proton)X At 2.1 Gev, Naipor Eric Cheung
Polarization Transfer Coefficient Measurements In The Deuteron Breakup Reaction Hydrogen-1(Polarized Deuteron,Polarized Proton)X At 2.1 Gev, Naipor Eric Cheung
Dissertations, Theses, and Masters Projects
The polarization of the protons emerging at 0$\sp\circ$ from the inclusive deuteron breakup reaction $\sp1$H($\vec d,\vec p$)X was measured using a deuteron beam with kinetic energy of 2.1 GeV. The momentum of the protons was selected by the magnetic spectrometer SPES4 and the polarization was measured with the polarimeter POMME. This experiment was performed at eight different proton momenta. When those momenta are Lorentz transformed to the deuteron rest frame, they corresponded to values from 0.00 to 0.34 GeV/c. The result of the measurements is expressed in terms of polarization transfer coefficient which is defined as the ratio of the …
Glueball Wave Functions And Production Cross Sections, Anthony B. Wakely
Glueball Wave Functions And Production Cross Sections, Anthony B. Wakely
Dissertations, Theses, and Masters Projects
Three topics are studied in this dissertation.;Using QCD sum rules, I first calculate the first few moments of the distribution amplitude of the pseudoscalar glueball, a bound state of gluons. The distribution amplitude is the momentum wave function integrated over the transverse momentum. QCD sum rules are a method of finding hadronic parameters using perturbative QCD. I use an approximation in which the glueball is treated as a narrow resonance. The moments of the distribution amplitude then give the corresponding first few coefficients of the distribution amplitude for the glueball expanded in Gegenbauer polynomials. The distribution amplitude is rather close …
Causal Synchrony In The Design Of Distributed Programs, Sandra L. Peterson
Causal Synchrony In The Design Of Distributed Programs, Sandra L. Peterson
Dissertations, Theses, and Masters Projects
The outcome of any computation is determined by the order of the events in the computation and the state of the component variables of the computation at those events. The level of knowledge that can be obtained about event order and process state influences protocol design and operation. In a centralized system, the presence of a physical clock makes it easy to determine event order. It is a more difficult task in a distributed system because there is normally no global time. Hence, there is no common time reference to be used for ordering events. as a consequence, distributed protocols …
Models For Water Outgassing From Metal Surfaces, Minxu Li
Models For Water Outgassing From Metal Surfaces, Minxu Li
Dissertations, Theses, and Masters Projects
In this study, the outgassing rate from an electropolished stainless steel surface following exposures to H{dollar}\sb2{dollar}O vapor under various conditions was measured. The results of the experiments showed that the outgassing rate is proportional to {dollar}p\sb0\sp{lcub}n{rcub}{dollar}, where {dollar}p\sb0{dollar} is the H{dollar}\sb2{dollar}O exposure pressure and n is about 0.25. The outgassing rate is not as strongly dependent on the system temperature as one would expect if the temperature is kept the same during exposure and pump-down. The outgassing rate is also a function of the exposure time for the first several hours of exposure, indicating that the adsorption saturation time is …
Effects Of Methyl Parathion On The Cellular Immune Responses In Giant Black Tiger Shrimp, Penaeus Monodon, Nantarika. Bodhipaksha
Effects Of Methyl Parathion On The Cellular Immune Responses In Giant Black Tiger Shrimp, Penaeus Monodon, Nantarika. Bodhipaksha
Dissertations, Theses, and Masters Projects
The effects of an organophosphorus pesticide, methyl parathion, on cellular immune defense mechanisms of the giant black tiger shrimp (Penaeus monodon) were studied. Animals were exposed for 96 hours at concentrations equal to, above and below the LC&\sb{lcub}50{rcub}& (3 ppb). Phagocytes were obtained from the heart and circulating hemolymph. Cellular immune responses, including chemotaxis, phagocytosis and the respiratory burst were examined. Chemotactic activity was determined by means of a modified Boyden double chamber technique. There was a dose-dependent decrease in the chemotactic activities of both circulating hemocytes and cardiac phagocytes. Phagocytic activity (percent phagocytosis) was examined by the microscopic enumeration …
Direct Determination Of Trace Metals In Saline Water Samples Using Gfaas, Michael Joseph Wassell
Direct Determination Of Trace Metals In Saline Water Samples Using Gfaas, Michael Joseph Wassell
Dissertations, Theses, and Masters Projects
No abstract provided.
Characterization And Modeling Of Amino Epoxide Resins, Maria Anastasia Argiriadi
Characterization And Modeling Of Amino Epoxide Resins, Maria Anastasia Argiriadi
Dissertations, Theses, and Masters Projects
No abstract provided.
Low Internal Magnetic Fields In Anisotropic Superconductors, Allan J. Greer Jr.
Low Internal Magnetic Fields In Anisotropic Superconductors, Allan J. Greer Jr.
Dissertations, Theses, and Masters Projects
This thesis is a theoretical, numerical study of the magnetic fields which exist in the anisotropic, high temperature superconductors like $YBa\sb2Cu\sb3O\sb{7-\delta}$, or YBCO for short, using both the anisotropic London theory and simulations based on existing muon spin rotation techniques. The thesis first describes the muon spin rotation ($\mu$SR) techniques, and then gives a brief discussion of superconductivity with regard to the London theory of anisotropic, type II superconductors. Next, numerical results of the application of this theory to YBCO are presented. Three dimensional surface plots of the magnetic field components within the flux line lattice (FLL) are shown, as …
The Requirements Of Patentability As Applied To The Chemical Arts, Joy L. Bryant
The Requirements Of Patentability As Applied To The Chemical Arts, Joy L. Bryant
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 …
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 …
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 …
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.
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.
In Situ Dielectric Monitoring And Kinetic Analysis Of Phase Separation, Theodore Joon Kim
In Situ Dielectric Monitoring And Kinetic Analysis Of Phase Separation, Theodore Joon Kim
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.
Cross-Linking Additives As Smoke Suppressants For Poly(Vinyl Chloride), Steven Alfred Terranova
Cross-Linking Additives As Smoke Suppressants For Poly(Vinyl Chloride), Steven Alfred Terranova
Dissertations, Theses, and Masters Projects
No abstract provided.
Responses Of Cytochrome P450ia In Freshwater Fish Exposed To Pulp Mill Effluents In Experimental Stream Channels, Laura Anne Bankey
Responses Of Cytochrome P450ia In Freshwater Fish Exposed To Pulp Mill Effluents In Experimental Stream Channels, Laura Anne Bankey
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.
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 …
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 …
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 …
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 …
The Metompkin Islands: A Case Study In Ownership And Management Of A Dynamic Barrier System, David Harold Niebuhr
The Metompkin Islands: A Case Study In Ownership And Management Of A Dynamic Barrier System, David Harold Niebuhr
Dissertations, Theses, and Masters Projects
No abstract provided.
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 …