Digital Commons Network^™

Hydrogen Sulfide And Radon In And Over The Western North Atlantic Ocean, T. W. Andreae, Gregory A. Cutter, N. Hussain, J. Radford-Knoery, M. O. Andreae

OES Faculty Publications

Atmospheric measurements of radon and hydrogen sulfide, and seawater measurements of total sulfide, free sulfide, and carbonyl sulfide, were made on a cruise in the western North Atlantic Ocean (October 24 to November 9, 1989). Measured values for ²²²Rn ranged from 3 to 70 pCi m⁻³, those for atmospheric hydrogen sulfide from 1 to 85 parts per trillion, and those for dissolved total and free sulfide in seawater from 33 to 930 pmol L⁻¹ and 0 to 73 pmol L⁻¹, respectively. A positive correlation between ²²²Rn and atmospheric H₂S was observed. …

Development And Evaluation Of Tracer Particles For Use In Microzooplankton Herbivory Studies, Mary Putt

OES Faculty Publications

Two methods of preparing algae for use as tracer particles in single species measurements of microzooplankton herbivory were evaluated. Algae were either heat-killed and labelled with 5-(4,6-dichlorotriazin-2-yl amino fluorescein) (DTAF) (Rublee & Gallegos 1989; Mar, Ecol. Prog. Ser. 51: 221-227) or stained with hydroethidine (HYD). Both DTAF and HYD-stained algae were readily visible within the digestive vacuoles of most microzooplankton collected in estuarine and coastal waters of Massachusetts (USA) and preserved with Lugol's iodine. However, DTAF was ineffective at staining several chromophytic algae and the heat-kill process reduced cell volume by ≥ 50% in several of the algae which were …

Trace Elements In Estuarine And Coastal Waters: U.S. Studies From 1986-1990, Gregory A. Cutter

OES Faculty Publications

The use of specialized analytical techniques, field studies, controlled laboratory experiments, and geochemical modeling have allowed U.S. investigators to expand our understanding of trace element cycling in coastal waters and estuaries. Considerable emphasis has been placed on quantifying the flux of trace elements within and through the coastal zone. In addition, substantial progress has been made in identifying the chemical speciation of many trace elements, providing a linkage between the geochemical and biochemical behavior of these elements. Another significant advance has been the use of trace elements as tracers of geochemical processes and water masses in the coastal environment.

United States Tactical Doctrine, 1855 To 1861: The Mismeasure Of Technology, Marion Vincent Armstrong Jr.

History Theses & Dissertations

This thesis illuminates the state of United States Army tactical doctrine at the beginning of the Civil War. In 1855, the weapons available to the United States Army left much to be desired in terms of firepower. Their limited range and lack of accuracy meant that they could not be relied upon to render the final decision in battle. The tactical system of 1855, however, blended this firepower with the shock action effect of bayonets and sabres, permitting the capabilities of the weaponry to be maximized on the battlefield while at the same time minimizing the deficiencies.

This harmony between …

Overall Laughing One And The Experiences, Anina Porter Adams

Institute for the Humanities Theses

A fictional play based on the study of writings by psychotherapist Carl Gustav Jung. The action is set in the imaginary realm of archetypes, amoral personified energies which appear in tales from diverse cultures. In this play the mythical characters move in an ordered, ritualistic manner. They are dependent upon a geometrically centered black box for the provision of human forms through which they experience "being." A female is the human form provided in this instance and she combines her own energy with that of the other characters though she is not conscious of this fact. The archetypal energies focus …

Best Lp Aapproximation With Multiple Constraints For 1 ⩽ P < ∞, J. J. Swetits, S. E. Weinstein, Yuesheng Xu

Mathematics & Statistics Faculty Publications

The problem considered in this paper is best L_p approximation with multiple constraints for 1 ⩽ p < ∞. Characterizations of best L_p approximations from multiple n-convex splines and functions are established and the relationship between them is investigated. Applications to best monotone convex approximation are studied.

Integration Of Abductive And Deductive Inference Diagnosis Model And Its Application In Intelligent Tutoring System, Jingying Zhang

Computer Science Theses & Dissertations

This dissertation presents a diagnosis model, Integration of Abductive and Deductive Inference diagnosis model (IADI), in the light of the cognitive processes of human diagnosticians. In contrast with other diagnosis models, that are based on enumerating, tracking and classifying approaches, the IADI diagnosis model relies on different inferences to solve the diagnosis problems. Studies on a human diagnosticians' process show that a diagnosis process actually is a hypothesizing process followed by a verification process. The IADI diagnosis model integrates abduction and deduction to simulate these processes. The abductive inference captures the plausible features of this hypothesizing process while the deductive …

Playdance, Gary Ryan Brown

Institute for the Humanities Theses

Playdance is a play in three acts which studies the relationships between parents and their children. The development of the script and the intended production was spurred by the pain that so many families experience as children grow away from their parents control. This look at the Denton household was an attempt to help understand the suffering and the feeling of solitude that so often accompanies this familial trauma. It was my intention to write a script that would be an exciting and insightful evening of theatre, but one that would remain accessible to a single and perhaps novice reader. …

Laureate, 1991, Old Dominion University

University Yearbooks

1991 yearbook of Old Dominion University

Effect Of Passive Flow-Control Devices On The Drug Of A Tractor-Trailer Model, Jagjit K. Ahuja

Mechanical & Aerospace Engineering Theses & Dissertations

The aerodynamic drag of tractor trailers is responsible for approximately half of the fuel consumption at highway speeds (55m.p.h.). Thus, it is important that vehicle drag be reduced in order to reduce operating costs and to conserve fuel. The purpose of the subject research conducted in the Old Dominion University Low-Speed Wind Tunnel was to determine the effect of various add-on flow-control devices, such as a cab-mounted flow deflector and gap seals between the tractor and the trailer. In addition, the effect of trailer rear-edge shaping has been studied. This was accomplished by contouring the trailer's rear end. It has …

History And Analysis Of Food Guides In The United States, Barbara B. Carlson

Health Services Research Dissertations

This work elucidates the development of nutrient-based dietary standards in the United States from the original energy and protein-based standards proposed by Atwater in 1894 to the micronutrient-based Recommended Dietary Allowances revised by the National Research Council in 1989. This qualitative historical research chronicles the development and subsequent revisions of nutrient-based food guides and food guidance models issued in the United States between 1916 and 1991. A literature search of historical food guides, research, and review papers from the fields of nutrition science and education, dietetics, and health science provided primary sources of information for the history. A literature search …

A Geophysical And Geological Study Of The Farmville Triassic Basin, Charles G. James Jr.

OES Theses and Dissertations

The Farmville basin is one of many Triassic basins which are found along the eastern coast of North America, and is the largest of the central string of basins in Virginia. Meta-volcanic and metasedimentary rocks of the Chopawamsic Formation, as well as felsic intrusives are the primary lithologies surrounding the basin. A detailed gravity survey was conducted along six roads that trend approximately NW-SE, across the basin. Geologic, gravity, magnetic, and radiometric data were used to develop a kinematic model. Gravity anomalies were isolated using two-dimensional harmonic analysis methods to isolate the local, and regional anomalies. This analysis indicates that …

The Ability Of The Special Needs Child In Comparison To The Average Child In A Beginning Computerized Keyboarding Class, Deborah K. Marshall

OTS Master's Level Projects & Papers

The problem of this study was to determine how the ability of the special needs child, when mainstreamed into a Beginning Computerized Keyboarding course, compared to that of the average child. The hypothesis was that there was no significant difference in the learning of special needs students and academically average students when taught Beginning Computerized Keyboarding.

A Study Comparing Basic Skills Of Computer Assisted Drafting Students To Traditional Drafting Students, Mark D. Pavlak

OTS Master's Level Projects & Papers

The problem will be addressed through the following hypotheses: 1. There is a significant difference in the performance of students enrolled in basic drafting who are taught CAD drafting instruction compared to those taught traditional drafting instruction in the quality of drawing; 2. There will be a significant difference in the technical proficiency of the CAD group compared to the technical proficiency of the traditional group.

Estimation In A Marked Poisson Error Recapture Model Of Software Reliability, Rajan Gupta

Mathematics & Statistics Theses & Dissertations

Nayak's (1988) model for the detection, removal, and recapture of the errors in a computer program is extended to a larger family of models in which the probabilities that the successive programs produce errors are described by the tail probabilities of discrete distribution on the positive integers. Confidence limits are derived for the probability that the final program produces errors. A comparison of the asymptotic variances of parameter estimates given by the error recapture and by the repetitive-run procedure of Nagel, Scholz, and Skrivan (1982) is made to determine which of these procedures efficiently uses the test time.

Information Technology And Wealth: Cybernetics, History And Economics, Elin Whitney-Smith

Engineering Management & Systems Engineering Theses & Dissertations

Capitalism developed where and when it did because there was high information access. There was high information access because of a major advance in information technology--the press. Where the technology was not controlled by the "powers that be" there was economic growth and a shift in the entire social structure. Where it was controlled there was no structural change and there was economic ruin. The development of capitalism is a major step change in economic growth. It is also a major change in the way people organize themselves into groups.

Major step changes in the growth and in the organization …

Feeding By Reticulitermes Spp., Deborah A. Waller

Biological Sciences Faculty Publications

No abstract provided.

Observations Of The Phytoplankton Standing Crop At The Shelf Margin Of The Mid Atlantic Bight, Bruce B. Wagoner, Harold G. Marshall

Biological Sciences Faculty Publications

A comparison of the total percentage cell abundance and cell biovolume relationships of major phytoplankton categories was made between two station sets across the shelf margin. Diatom values for abundance and biovolume were greater at oceanic stations compared to the outer shelf stations, with dinoflagellates having the reverse pattern. The composite contributions to biovolume and abundance in the standing crop from other phytoplankton categories were greater over the outer shelf than beyond the shelf margin. The major source of biovolume (biomass) from the outer shelf and these oceanic stations came from the diatoms and dinoflagellates, with an average mean of …

Numerical Modeling Of Flame Lift-Off Phenomenon And Calculation Of Thermal Loads On A Methane Fuel Injector With Complex Geometry, Taj O. Mohieldin

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical study has been conducted to analyze a fuel injector with three in-line cylinder geometry that has been adopted as a model for investigating the combustion phenomenon in the 8-Foot High Temperature Tunnel (HTT) combustor at the NASA Langley Research Center. The primary objective here is to analyze the flame lift-off phenomenon in the three cylinder fuel injector geometry in two-dimensions. The fluid mechanics model used in the analysis includes time-averaged Navier-Stokes equations that are employed in conjunction with a two-equation k-$\epsilon$ model for predicting the effects of turbulence. Calculations were performed with three chemistry models, namely fast chemistry, …

Identification Of The Potential High School Dropout, Alan L. Vaughan

Theses and Dissertations in Urban Services - Urban Education

This research was conducted to determine a methodology for the early identification of potential dropouts in the Chesapeake Public School System. A review of research literature determined that many discriminating characteristics had been identified as influential in a student's decision to drop out or stay in school. This study sought to be useful in a practical school setting. Therefore, the study limited its scope to those discriminating characteristics available in student records and thus readily accessible to school personnel. The predictor variables listed below are well documented in the research as discriminating characteristics relating to a student dropping out of …

Compressed Digital Video Instructional Delivery: A Study Of Student Achievement, Student Attitude, And Instructor Attitude, Eddyth Niceler Worley

Theses and Dissertations in Urban Services - Urban Education

The purpose of this study was to investigate compressed digital video as an instructional delivery system for distance learning. The independent variable was delivery mode. Two levels of this variable were considered. Level 1 was one-way video/two-way audio. Level 2 was two-way video/two-way audio. Student achievement, student attitude, and instructor attitude were measured as dependent variables.

A quasi-experimental study comparing the two delivery modes was conducted. Two treatment groups were established. Both groups received instruction simultaneously from the same instructors. Instructors used both treatment modes (delivery systems) during instruction.

Instructor and student subjects were naval, civilian and military personnel involved …

Second Coefficient Of Viscosity In Air, Robert L. Ash, Allan J. Zuckerwar, Zhonquan Zheng

Mechanical & Aerospace Engineering Faculty Publications

Acoustic attenuation measurements in air were analyzed in order to estimate the second coefficient of viscosity. Data over a temperature range of 11 C to 50 C and at relative humidities between 6 percent and 91 percent were used. This analysis showed that the second coefficient of viscosity varied between 1900 and 20,000 times larger than the dynamic or first coefficient of viscosity over the temperature and humidity range of the data. In addition, the data showed that the molecular relaxation effects, which are responsible for the magnitude of the second coefficient of viscosity, place severe limits on the use …

Role Of Surface Morphology In Wafer Bonding, W.P. Maszara, B.L. Jiang, A. Yamada, G.A. Rozgonyi, H. Baumgart, A.J.R. De Kock

Electrical & Computer Engineering Faculty Publications

The strain patterns detected by x-ray topography in wafers bonded for silicon-on-insulator (SOI) technology were found related to the flatness nonuniformity of the original wafers. Local stresses due to the bonding process are estimated to be about 1×10⁸ dynes/cm². The stress is reduced about 100 times for the thin (0.5 μm) SOI films. Most of the wafer deformation occurs during room temperature mating of the wafers. The deformation is purely elastic even at 1200 °C. The magnitude of the stress appears insignificant for complimentary metal-oxide-semiconductor devices performance.

Parametric Instability Of Supersonic Shear Layers Induced By Periodic Mach Waves, Fang Q. Hu, Christopher K. W. Tam

Mathematics & Statistics Faculty Publications

It is suggested that parametric instability can be induced in a confined supersonic shear layer by the use of a periodic Mach wave system generated by a wavy wall. The existence of such an instability solution is demonstrated computationally by solving the Floquet system of equations. The solution is constructed by means of a Fourier-Chebyshev expansion. Numerical convergence is assured by using a very large number of Fourier and Chebyshev basis functions. The computed growth rate of the induced flow instability is found to vary linearly with the amplitude of the mach waves when the amplitude is not excessively large. …

Nonlinear-Interaction Of A Detonation Vorticity Wave, D. G. Lasseigne, T. L. Jackson, M. Y. Hussaini

Mathematics & Statistics Faculty Publications

The interaction of an oblique, overdriven detonation wave with a vorticity disturbance is investigated by a direct two-dimensional numerical simulation using a multidomain, finite-difference solution of the compressible Euler equations. The results are compared to those of linear theory, which predict that the effect of exothermicity on the interaction is relatively small except possibly near a critical angle where linear theory no longer holds. It is found that the steady-state computational results whenever obtained in this study agree with the results of linear theory. However, for cases with incident angle near the critical angle, moderate disturbance amplitudes, and/or sudden transient …

A Duality Approach To Best Uniform Convex Approximation, S. E. Weinstein, Yuesheng Xu

Mathematics & Statistics Faculty Publications

Let C[a, b] be the space of continuous functions on [a, b] endowed with the uniform norm llƒll _∞ = sup{ Iƒ(x)1 :x∈ [a, b]}. Let K be the set of convex functions defined on [a, b]. A function g* ∈ K is said to be a best uniform convex approximation to ƒ ∈ C[a, b] if ∥ƒ - g*∥ _∞ = inf { ∥ƒ - g∥_∞ : g ∈ K}.

Comparison Of Digital Controllers Used In Magnetic Suspension And Balance Systems, William A. Kilgore

Mechanical & Aerospace Engineering Faculty Publications

Dynamic systems that were once controlled by analog circuits are now controlled by digital computers. Presented is a comparison of the digital controllers presently used with magnetic suspension and balance systems. The overall responses of the systems are compared using a computer simulation of the magnetic suspension and balance system and the digital controllers. The comparisons include responses to both simulated force and position inputs. A preferred digital controller is determined from the simulated responses.

Trace Metals And Pyrite In Sediments Of Chesapeake Bay, Robert S. Kluckhohn

OES Theses and Dissertations

The formation and cycling of iron sulfides within anoxic sediments can affect the cycling of trace metals. The sediments at station CB-27 (near Annapolis, Maryland) in Chesapeake Bay were rich in FeS (39% of TS), low in greigite (3.6% of TS), and has a relatively constant pyrite concentration (50 - 60% of TS) with depth. The percent composition of total metals in pyrite were 25.7% cu, 11.8% Zn, 15.8% Fe, and non-detectable to 2.1% Cd. At Station CB- 28 (near the Choptank River), the sediments were low in FeS (1.7% of TS), richer in greigite (up to 14% of TS), …

Integrated Control Of Thermally Distorted Large Space Antennas, Robert H. Tolson

Mechanical & Aerospace Engineering Theses & Dissertations

Studies on controlling the thermal distortion of large space antennae have generally investigated a single orbital position and have optimized actuator locations based on minimizing the RMS surface deviation from the original parabolic shape. One study showed the benefits of directly using far zone electric field characteristics as the performance measure; but, this approach resulted in a nonlinear programming problem. The objective of the current study is to develop an approach to designing a control system that (1) recognizes the time dependence of the distortion and (2) controls variables that are directly related to far field performance in a quadratic …

The Effectiveness Of Viscoelastic Damping Treatments On A Flexible Manipulator Subjected To Torsional Loads, Leah L. Remias

Mechanical & Aerospace Engineering Theses & Dissertations

The advent of new technology has led to an increasing number of missions in space. The space shuttle Remote Manipulator System (RMS) is a lightweight flexible manipulator currently used in NASA space missions. The future role of the RMS and similar flexible manipulators may include in-space construction and assembly tasks. Because these tasks require precise motion and short settling time of the end-point oscillations, effective vibration control schemes are being investigated.

Passive damping techniques have shown to provide a considerable amount of damping in controlling flexural vibrations. In this research passive damping via constrained viscoelastic damping treatments is explored as …