Physical Sciences and Mathematics Commons^™

An Evaluation Of A Stable Isotope Of Dysprosium For Labeling And Tracing Sedimentary Particles, Charles Glenn Boone

OES Theses and Dissertations

An evaluation of the application of dysprosium oxide as a tracer coating to surface label sedimentary particles is made. Physical and chemical properties of the labeled sand are studied. Effective diameters and settling properties of the tracer sand are compared with unlabeled sand. A total of 8.51 kg of labeled sand was placed on the beach at Camp Pendleton. Dispersal patterns obtained 1 and 4 hours after tracer injection indicate a general down current mean tracer migration rate of 0.21 cm/sec (0.42ft/sec). An absolute detection limit of 4 or 5 parts per 100,000 and a real detection limit, after field …

An Application Of Spectroscopic Techniques To The Measurement Of Electron Density And Temperature In A Brush Cathode Plasma, Ramabhai M. Patel

Physics Theses & Dissertations

A brief review of the Langmuir probe, microwave and spectroscopic techniques most commonly used to make measurements .of plasma electron temperature and density is presented. Of these various methods, certain spectroscopic methods are applied to the measurements of electron density and temperature in a helium brush cathode plasma. The density measurement is based on the manner in which a series of Stark broadened spectral lines merges into an apparent continuum before the normal series limit is reached. This approach met with only limited success in that the density could be determined only by extrapolating the data obtained. Primarily because of …

Analysis Of Littoral Transport By Wave Energy: Cape Henry, Virginia To The Virginia, North Carolina Border, Zvi Henry Weinman

OES Theses and Dissertations

An investigation of the rate of littoral transport by an analysis of wave energy for the area from Cape Henry, Virginia to the Virginia, North Carolina border is made. Wave refraction diagrams are done by digital computer. Total upcoast (northerly) transport is determined to be 2.05 x 10⁶ yds³/year. Total downcoast (southerly) transport is determined to be 1.07 x 10⁶ yds³/year. Net transport is determined to be 9.8 x 10⁵ yds³/year in an upcoast (northerly) direction. The values obtained are compared with those of similar areas. The general efficacy of the …

Observations On The Hydraulic Regime Of The Ridge And Swale Topography Of The Inner Virginia Shelf, Barry W. Holliday

OES Theses and Dissertations

The Virginia inner shelf is dominated by southwest-trending sand ridges. Wavelengths are 2 to 4 km; amplitudes are up to 10 m; crests can be traced for up to 10 cm, Nearshore ridges trend southwest into the shore face and merge with it at depths as shoal as 5 m. The ridges have been examined by bathymetric mapping, grab sampling, coring, seismic profiling, SCUBA diving, and current monitoring. They are hemi-cylindrical sand bodies of recent age, resting on a pre-recent substrate. In troughs a thin, medium- to coarse-gained, pebbly lag veneers the substrate. Crests consist of a better sorted, medium- …

A Graphic Analysis Of Current Velocity Salinity Density And Temperature During Periods Of Ebb And Flood In The Entrance To Thimble Shoals Channel, Stanley Hecker

OES Theses and Dissertations

A graphic analysis is presented of the observed patterns of longitudinal current velocity, salinity, density and temperature through a group of tidal cycles in Thimble Shoals Channel. Graphs of the properties indicate that this estuary passes through a sequence of estuarine types during a tidal cycle. In spite of this observation, the net non-tidal profiles of salinity are patterns of a partially mixed estuary.

The most noteworthy observation in this study was that longitudinal velocity was essentially constant throughout the water column at any increment of a tidal cycle as well as in the net non-tidal profile of the water …

Phytoplankton Composition At Lake Drummond In The Dismal Swamp, Virginia, William Howard Poore Jr.

Biological Sciences Theses & Dissertations

Abstract unavailable.

Spectroscopic Measurement Of The Electron Temperature In The Tenuous Argon Ion Laser Plasma, Dane Danijel Bicanic

Physics Theses & Dissertations

The validity of the line intensity ratio technique for measuring the electron temperature was examined for an argon plasma with a "population inversion" i.e., the number of ions with electrons in the upper 4p levels was greater than in the lower 4s levels. The line intensities from these levels, the argon ion lasing transitions, were measured in a pulsed tenuous plasma at 110μ Hg produced by discharging a capacitor through a tube 2m long and 7mm inside diameter. The electron impact cross sections for simultaneous excitation and ionization as measured by Latimer and St. John were used and averaged over …

Nutrient-Density Relationships In The Western North Atlantic Between Cape Lookout And Bermuda, Unnsteinn Stefánsson, Larry P. Atkinson

CCPO Publications

A study of the nutrient-density relationships of Sargasso Sea water reveals a close correlation; Gulf Stream waters are anomalously higher and more variable in nutrients for a given density. Nutrient anomalies can be used in the same way as oxygen anomalies to map the distribution of Caribbean water in sections across the Gulf Stream. They show that contributions of Caribbean water to the Gulf Stream vary greatly from time to time. Oxidative ratios of ΔO : ΔN : ΔP = (−233) : 16.3 : 1.0 were derived from the correlation between oxygen anomalies and nutrients anomalies of Gulf Stream water …