Physical Sciences and Mathematics Commons^™

Absorption Cross-Sections Of Sodium Diatomic Molecules, Zeng-Shevan Fong

Physics Theses & Dissertations

The absorption cross sections of sodium dimers were studied using a heat pipe over operating in the non-heat-pipe mode. Three wavelength regions were observed. They are in the red, the green-blue, and the near ultraviolet regions. The absorption cross section depends on the wavelength of the incident light. Representative peak values for the v"=0 progression in the red and green-blue regions are 2.59 A sup 2 (average value) and 11.77 A sup 2 (T_ave=624 K). The value for the C greater than X transitions is several tenths A sup 2. The cross sections were measured from absorption spectra …

Leachate Monitoring In Naturally Saline Groundwater Chesapeake Landfill Chesapeake Virginia, T. Britt Mcmillan

OES Theses and Dissertations

Groundwater chemistry around the Chesapeake municipal landfill was monitored over a one year period. Ten sample sites as well as two surface water sites were used to monitor water quality. Two wells, one at 3 m and the other at 10 m were located at each site. Surface water samples were taken from the Elizabeth River, north of the landfill, and a tidal channel, west of the landfill. Seven groundwater sites were downgradient of the landfill and three sites were upgradient (control sites).

The landfill overlies a tidal marsh, approximately 100 m south of the intracoastal waterway (Elizabeth River). Dredge …

Investigation Of Eddy Population And Motion In The Southern International Ice Patrol Operations Area (40°-47°N By 40°-55°W), Frank J. Williams

OES Theses and Dissertations

A study of the eddy population in the Newfoundland Basin region over the period from November 1981 to December 1984 was conducted. The study was undertaken to demonstrate the importance and basic character of eddy motion in the area patrolled by the International Ice Patrol. This is a descriptive study and no rigorous mathematical solutions are attempted. Data was collected on the number of eddies in the area, their average duration and size, formation, migration and deterioration patterns and rotational velocity. Satellite infrared imagery maintained by National Weather Service and Naval Eastern Oceanographic Center, Canadian Forces METOC Center sea surface …

Lineament Analysis And Tectonic Interpretation For The Central Tharsis Region, Mars, Robert C. Anderson

OES Theses and Dissertations

Lineament studies conducted for the Central Tharsis Region of Mars (JOON and JOOS latitude; 450w to 157.50W longitude) indicate two major events controlled the formation of the Tharsis Dome: 1) a pre-Tharsis fracture system consisting of North-West (3150) trending fractures; and 2) a Tharsian fracture system containing North-South (355°) and East-West (275°) trending fractures. The North-West (3150) trending fractures represent a crustal weakness zone which controlled the early formation of the Tharsis Dome. Analytical studies suggest four centers of uplift: 1) 6°N, 124°W; 2) 0.5°N, 114°W; 3) 5°S, 105°W; and 4) 7°S, 104°W. Each of these uplifting centers is associated …

Depositional Model For The Auriferous Gravels In The Payan Mining District Department Of Narino, Columbia, South America, Jim R. Garrett

OES Theses and Dissertations

Unlike placer deposits in arid and semi-arid environments where gold concentration is closely tied to the position of the bedrock, Payan placer deposits have no association with bedrock. Gold concentration values show highest gold concentrations occur at the contact of a coarse sand unit and its underlying gravel unit. Comparisons of the size and shape distributions of gold grain populations with their associated black sand populations indicate the gold and black sand were not deposited in hydraulic equilibrium. The mean size of each gold population is consistently coarser than the mean size of its associated black sand population despite the …

Depositional Environments Of Late Precambrian Sediments From Liberia, Sierra Leone, And Senegal, West Africa, Alfred W. Magee Iii

OES Theses and Dissertations

Field and hand sample descriptions were supplemented with petrographic and textural analyses derived from thin sections, and scanning electron microscopy (SEM) to determine environments of deposition for the late Precambrian Gibi Mountain Formation, Liberia, Tabe

Formation, Sierra Leone, and the basal Mali Group, Senegal, West Africa.

The Gibi Mountain Formation consists of a glaciomarine tillite, marine laminites with dropgrains, and shallow water arkoses. A shale facies remains unresolved in origin.

The Tabe Formation is composed of three members: Tibai, Dodo, and Taban. The Tibai Member contains a glaciomarine tillite deposited in a shallow shelf marine environment, marine laminites, and shallow …

Comparison Of An Improved Plankton Sampler To The Standard Conical Plankton Net, Ronald S. Schmidt

OES Theses and Dissertations

A comparison of field and tank tests between the standard conical plankton net and an improved version of a plankton sampler is presented. The improved sampler was shown to filter larger quantities of water than the standard net without having the filtration efficiency reduced below 85%. The improved sampler was also shown to capture an increased number of plankton per volume sampled, as a result of eliminating increased avoidance activity by zooplankton. It was not shown that. the improved sampler capture either larger maximum sizes of zooplankton or additional species.

Conodont Biostratigraphy Of The Cambrian-Ordovician Boundary Interval In The Northern Shenandoah Valley Of Virginia, U.S.A., Randall C. Orndorff

OES Theses and Dissertations

Conodonts collected from two measured sections in the northern Shenandoah Valley of Virginia indicate that locally the Cambrian-Ordovician boundary is within the upper part of the Conococheague Formation and that the Conococheague-Stonehenge formational contact as defined in this study, is diachronous in relation to the boundary. Using the generally accepted definition of the CambrianOrdovician boundary as at the base of the trilobite Missisguoia Zone or within the conodont Hirsutodontus hirsutus Subzone of the Cordylodus proavus Zone, it is found here that the boundary is 230 ft (70 m) below the formational contact at the Narrow Passage Creek section. Several North …

Development Of An On-Line Computer System For Cyclic Voltammetry Studies, Tai-Lee Leo Huo

Chemistry & Biochemistry Theses & Dissertations

An Apple II Plus microcomputer was interfaced to a PAR 174A Polarographic Analyser, an HP 7O4OA X-Y recorder and a three-electrode system. This on-line computer system was applied to Cyclic Voltammetry (CV) studies. The interfacing involved both hardware and software development. Various hardware components were used to amplify and transmit the analog signal both going into the computer and coming from the computer. Software programs were written for staircase waveform generation, data acquisition, and plotting the voltammograms obtained.

A package was designed for CV experiments to be used by the students in the instrumental analysis laboratory. This package contains several …

The Apparent Dissociation Constants Of Carbonic Acid In Low Salinity Waters, Ching-Hui Hsu

OES Theses and Dissertations

The first and second apparent dissociation constants of carbonic acid in artificial seawater and diluted artificial seawater, K₁ ' and K₂ 1 were determined at selected combinations of temperatures and salinities between 2 to 30° C and 0 to 35 o/oo with special attentions to waters with salinities below 20 o/oo at atmospheric pressure by measuring K₁ ' and the product of K₁ ' and K₂.

The results can be expressed as functions of temperature and salinity by the following equations, pK₁ '=3360.206T^-1 +0. 033331 T-14.8303-0.09633x (Cl^1/2) pK₂ '=14911.671 …

Minimal Norm Constrained Interpolation, Larry Dean Irvine

Mathematics & Statistics Theses & Dissertations

In computational fluid dynamics and in CAD/CAM a physical boundary, usually known only discreetly (say, from a set of measurements), must often be approximated. An acceptable approximation must, of course, preserve the salient features of the data (convexity, concavity, etc.) In this dissertation we compute a smooth interpolant which is locally convex where the data are locally convex and is locally concave where the data are locally concave.

Such an interpolant is found by posing and solving a minimization problem. The solution is a piecewise cubic polynomial. We actually solve this problem indirectly by using the Peano kernel theorem to …

Algebraic Grid Generation Using Tensor Product B-Splines, Bonita Valerie Saunders

Mathematics & Statistics Theses & Dissertations

In general, finite difference methods are more successful if the accompanying grid has lines which are smooth and nearly orthogonal. This thesis discusses the development of an algorithm which produces such a grid when given the boundary description.

Topological considerations in structuring the grid generation mapping are discussed. In particular, this thesis examines the concept of the degree of a mapping and how it can be used to determine what requirements are necessary if a mapping is to produce a suitable grid.

The grid generation algorithm uses a mapping composed of bicubic B-splines. Boundary coefficients are chosen so that the …

Feasibility Studies Of Conversion Electron Mossbauer Spectroscopy (Cems) Of Iron-Doped Inp, Edward Agyekum

Physics Theses & Dissertations

An electron detector for conversion electron Mossbauer spectroscopy (CEMS) has been designed and built. Tests have been performed to study the effects on the electron detector resolution with respect to high anode voltage, He/CH₄ gas flow rate, and counting rate. These parameters have been optimized to detect the 7.3 keV conversion electrons emitted following resonant absorption of the 14.4 keV source gamma-rays associated with the Mossbauer effect using ⁵⁷Fe nuclei. CEMS spectra have been obtained using standard ⁵⁷Fe enriched and natural iron samples. CEMS spectra and Mossbauer transmission spectra have also been obtained for iron-compensated InP (InP:Fe) …

Foraminiferal Paleoenvironments Of The Eastover Formation (Upper Miocene Virginia), Joann H. Goshorn

OES Theses and Dissertations

Sixty-two taxa representing 29 genera from 39 foraminiferal sample pairs have been documented and analyzed in a paleoenvironmental study of the Eastover Formation in southeastern Virginia. The Eastover Formation consists of a lower Claremont Manor Member, a silt fine-grained sand and an upper Cobham Bay Member, a shelly fine grained sand. Planktonic specimens were rare and indicated a late Miocene to early Pliocene age for the Eastover Formation. Benthics were used to interpret paleoenvironments by comparison with data from the distribution of Recent foraminifera, species diversity, planktonic to benthic ratios, and sediment analyses. The foraminifera indicate that the Eastover Formation …

Fluvial Depositional Processes Of A Tropical River, Colombia, South America, Michael L. Babuin

OES Theses and Dissertations

Fluvial depositional processes along the Rio Magui in south-western Columbia are primarily controlled by localized uplift downstream of the mouth of the river, sediment sources that produce both coarse-and-fine-grained load, and numerous over-bank flows caused by torrential rainfall.

The Synthesis And Evaluation Of A New Analog Of Phencyclidine (Pcp), William H. Johnson Jr.

Chemistry & Biochemistry Theses & Dissertations

Based on an interpretation of the literature of phencyclidine (PCP) together with an examination of the relevant models or prototype structures, this research has attempted to design and synthesize a rigid analog of the phencyclidine structure. The parent ring systems suggested for this study were the 1-arnino and 2-arninornethyltetralins, 10 and, 12.

Several organic compounds, based on this design, have been prepared by classical examples of reductive alkylation reactions of the corresponding 2-hydroxyciethylene-1-tetralones, 11, and by the condensation and subsequent reductive alkylation of the 1-arninotetralin, 9. These arninomethyltetralones, 28, 29 and 30, together with an example of a substituted 1-arninotetralin, …

Statistical Calibration Theory, James John Mckeon

Mathematics & Statistics Theses & Dissertations

A calibration method substitutes for measurements, X(,i), that are accurate but impractical or costly, a set of measurements, Y(,i), that are less accurate but simpler or less costly. There are two general types of calibration methods. The classical approach in which once the calibration sample is drawn, the estimates of the X values for a given unit is found without any consideration of the distribution of X values for the other units to be measured. This corresponds best to the literal meaning of the word "calibration". Maximum likelihood estimation is the statistical formulation of the classical approach.

The second approach …

A Geophysical Model Of The Gravity-Magnetic High, Virginia Coastal Plan, Gordon Everett Davison

OES Theses and Dissertations

The coastal plain province of Virginia is characterized by a coincidental gravity and magnetic high separating Appalachian-trend geophysical signatures to the west from non-Appalachian signatures to the east. Two cross-trend gravity and magnetic profiles, one on the Northern Neck of Virginia and one along Interstate Highway 64, were used to interpret the anomalous high. The profile models suggests that the anomaly is characterized by high-density, variably magnetic, east-dipping (60°) crustal blocks. Further information from well-logs indicate that the anomaly is due to meta-mafic rocks of oceanic origin, flanked by low-density, lower susceptibility, granitic units. This suggests that the anomalous gravity-magnetic …

Sedimentologic And Stratigraphic Significance Of Boulder Layers In The Outer Coastal Plain Of Southeastern Virginia, Robert C. Mcdaniel

OES Theses and Dissertations

In southeastern Virginia one to two discontinuous boulder layers occur at the base of the Pleistocene Norfolk Formation. The sediments, heavy minerals and microfossils within the boulder layers in addition to boulder lithologies, dimensions and orientations were studied to determine the origin of these layers. These data indicate the boulder layers were separated into two similar yet distinct layers.

The ancestral James River with sea-level 100 meters lower than today probably had the capacity to entrain 70-80 percent of the clasts in the boulder layers, but probably not the capacity to entrain the larger cobbles and boulders in the boulder …

The Use Of Ilmenite Element Composition For The Determination Of Provenance, Yu W. Tsang

OES Theses and Dissertations

Fifty three samples were taken from three major rivers and their tributaries in Virginia: the James, Roanoke. and Potomac-Shenandoah Rivers. Samples were obtained from the Valley and Ridge. Blue Ridge and Piedmont provinces. The possible source rock types for these samples were determined by comparison of tributary ilmenite composition with drainage basin rock types. Ilmenite element concentration varied with different rock types. Ti was usually high for the ilmenite derived from non-mafic igneous rocks. Mg and Cr were high for the ilmenite from mafic igneous rocks. Zn was low for metamorphic ilmenite. The ilmenite from sedimentary rocks tended to have …