Digital Commons Network^™

Fiber-Optic Coupled Lidar Receiver System To Measure Stratospheric Ozone, David Brent Harper

Electrical & Computer Engineering Theses & Dissertations

A fiber-optic coupled lidar receiver system was constructed to determine ozone concentrations in the stratosphere. The system was used to make ground-based measurements of lidar returns from a UV DIAL system. A fiber-optic cable was used to couple the light from the receiver telescope to the light detector. Photon counting was implemented as the light detection technique. This technique allowed detection of 301 and 311 nm lidar returns up to 27.5 and 32.5 km respectively. A software application was developed to control the photon counting system and perform real-time data analysis of measured lidar returns. DIAL measurements of stratospheric ozone …

Direct Current High-Pressure Glow Discharges, Robert H. Stark, Karl H. Schoenbach

Bioelectrics Publications

Stabilization and control of a high-pressure glow discharge by means of a microhollow cathode discharge has been demonstrated. The microhollow cathode discharge, which is sustained between two closely spaced electrodes with openings of approximately 100 μm diam, serves as plasma cathode for the high-pressure glow. Small variations in the microhollow cathode discharge voltage generate large variations in the microhollow cathode discharge current and consequently in the glow discharge current. In this mode of operation the electrical characteristic of this system of coupled discharges resembles that of a vacuum triode. Using the microhollow cathode discharge as plasma cathode it was possible …

Direct Current Glow Discharges In Atmospheric Air, Robert H. Stark, Karl H. Schoenbach

Bioelectrics Publications

Direct current glow discharges have been operated in atmospheric air by using 100 μm microhollow cathode discharges as plasma cathodes. The glow discharges were operated at currents of up to 22 mA, corresponding to current densities of 3.8 A/cm² and at average electric fields of 1.2 kV/cm. Electron densities in the glow are in the range from 10¹² to 10¹³  cm⁻³. Varying the current of the microhollow cathode discharge allows us to control the current in the atmospheric pressure glow discharge. Large volume atmospheric pressure air plasmas can be generated by operating microhollow cathode discharges …

Design And Construction Of A Mobile Laboratory For Distance Learning In Engineering Technology, Alok K. Verma

Engineering Technology Faculty Publications

The design and construction of a mobile laboratory to be used in conjunction with the televised program in Mechanical Engineering Technology Program at Old Dominion University is discussed. The aim of this program is to offer educational opportunities to individuals currently employed with an associate degree. The merit of the concept lies in the fact that it offers a cost effective way to provide a laboratory for multiple sites. Currently, the concept is being tested for two instructional areas, such as fluid mechanics and automatic controls.

High-Performance Bus-Based Architectures - Guest Editorial, Stephan Olariu, Rong Lin

Computer Science Faculty Publications

(First paragrapg) This special issue of VLSI Design presents a collection of seven papers selected out of more than 35 submissions received following the Call for Papers. Each submission was sent to three referees, all of them experts in the area of bus-based architectures. The result is impressive. The papers featured in this Special Issue cover a wide range of topics from sorting to string matching, to load balancing, to simulation, matrix operations, to robotics, to the design of high-performance scalable architectures.

Smart Objects, Dumb Archives: A User-Centric, Layered Digital Library Framework, Kurt Maly, Michael L. Nelson, Mohammad Zubair

Computer Science Faculty Publications

Discusses digital libraries, interoperability, and interfaces to access them, and proposes one universal protocol for communication for simple archives based on the hypertext transfer protocol (http). Describes the creation of a special class of digital objects called buckets, archives based on a NASA collection, and a set of digital library services. (Author/LRW)

Compute As Fast As The Engineers Can Think! Utrafast Computing Team Final Report, Robert T. Biedron, P. Mehrotra, Michael L. Nelson, M. L. Preston, J. J. Rehder, J. L. Rogersm, D. H. Rudy, J. Sobieski, O. O. Storaasli

Computer Science Faculty Publications

This report documents findings and recommendations by the Ultrafast Computing Team (UCT). In the period 10-12/98, UCT reviewed design case scenarios for a supersonic transport and a reusable launch vehicle to derive computing requirements necessary for support of a design process with efficiency so radically improved that human thought rather than the computer paces the process. Assessment of the present computing capability against the above requirements indicated a need for further improvement in computing speed by several orders of magnitude to reduce time to solution from tens of hours to seconds in major applications. Evaluation of the trends in computer …

A Digital Library For The National Advisory Committee For Aeronautics, Michael L. Nelson

Computer Science Faculty Publications

We describe the digital library (DL) for the National Advisory Committee for Aeronautics (NACA), the NACA Technical Report Server (NACATRS). The predecessor organization for the National Aeronautics and Space Administration (NASA), NACA existed from 1915 until 1958. The primary manifestation of NACA's research was the NACA report series. We describe the process of converting this collection of reports to digital format and making it available on the World Wide Web (WWW) and is a node in the NASA Technical Report Server (NTRS). We describe the current state of the project, the resulting DL technology developed from the project, and the …

Algorithms For The Numerical Solution Of A Finite-Part Integral Equation, J. Tweed, R. St. John, M. H. Dunn

Mathematics & Statistics Faculty Publications

The authors investigate a hypersingular integral equation which arises in the study of acoustic wave scattering by moving objects. A Galerkin method and two collocation methods are presented for solving the problem numerically. These numerical techniques are compared and contrasted in three test problems.

Brain Sex: How The Media Report And Distort Brain Research, Janet M. Bing

English Faculty Publications

Testosterone gives men a particular advantage in that it is focusing and galvanizing a brain that is already, by its very structure, more focused than the female. Remember that the male brain is a tidier affair, each function in its special place . . . Biology, then, every bit as much as social conditioning, militates against a strongly feminine role in areas traditionally regarded as male preserves.

Warm Water Formation And Escape In The Upper Tropical Atlantic Ocean - 2. A Numerical Model Study, Sang-Ki Lee, G. T. Csanady

CCPO Publications

We seek the simplest mass and heat balance scenario within the upper tropical Atlantic Ocean using a 2.5-layer numerical model, with the help of a newly suggested entrainment formula. The model ocean is driven by the seasonal wind and heat flux associated with the movement of the Intertropical Convergence Zone (ITCZ). The entrainment rate is scaled by the product of wind stress and shear at the bottom of the mixed layer. On an annual average, the northward transport of the tropical warm water is about 11 Sv, with roughly 10 Sv associated with entrainment of upper thermocline water. Out of …

Benchmarking Financial Operations Using The Premier Operations Outlook Database, Margaret M. Thompson

Community & Environmental Health Theses & Dissertations

Acute-care hospitals have come under increased pressure to reduce costs while increasing the quality of providing care. Historically, increasing costs of providing care has had the greatest impact on the reduction of operating margins necessary to expand capital and for repayment of debt. Facilities can benchmark internal historical data to identify areas where costs have increased and are able to explain the factors that contribute to the increases. One of the challenges facing hospitals in their efforts to reduce operating costs is how, what, and where, do they obtain comparative data to benchmark the cost of operating medical facility to …

Continuous Adjoint Sensitivity Analysis For Aerodynamic And Acoustic Optimization, Kaveh Ghayour

Mechanical & Aerospace Engineering Theses & Dissertations

A gradient-based shape optimization methodology based on continuous adjoint sensitivities has been developed for two-dimensional steady Euler equations on unstructured meshes and the unsteady transonic small disturbance equation. The continuous adjoint sensitivities of the Helmholtz equation for acoustic applications have also been derived and discussed.

The highlights of the developments for the steady two-dimensional Euler equations are the generalization of the airfoil surface boundary condition of the adjoint system to allow a proper closure of the Lagrangian functional associated with a general cost functional and the results for an inverse problem with density as the prescribed target. Furthermore, it has …

Multidisciplinary Sensitivity Analysis And Design Optimization Of Flexible Wings Using The Euler Equations On Unstructured Grids, Arunkumar Satyanarayana

Mechanical & Aerospace Engineering Theses & Dissertations

Aeroelasticity is a classical discipline. However, even with recent advancement in computational technology, it still remains a challenging discipline. This is particularly true when aeroelasticity problems are solved in a loosely coupled manner. The advantage of a loosely coupled scheme is that the legacy codes of computational fluid dynamics (CFD) and computational structural mechanics (CSM) can be preserved and used as independent modules in solving the desired aeroelasticity problems. In such a scheme, maintaining proper data transfer (load transfer and deformation tracking between CFD and CSM codes) is crucial in ensuring successful coupled solutions. This can be a challenging task …

Studies Related To The Design Of A Magnetic Suspension And Balance System For An Ultra-High Reynolds Number Flow Facility, Oscar Magno Michael Gomeiz

Mechanical & Aerospace Engineering Theses & Dissertations

The basic design principles for a magnetic suspension and balance system applied to the test section of an ultra-high Reynolds number facility are defined. The design of the cross-sectional area to be used in the test section is analyzed. The parameters of the permanent magnet to be used in the model inside the test section are investigated. The testing of magnetic fields at the center of a test pipe and validation of data by computer finite element analysis is described with the purpose of finding common results. The performance of the magnet configuration is evaluated with relation to the magnetic …

Setpoint Tracking Predictive Control In Chemical Processes Based On System Identification, Sinchai Chinvorarat

Mechanical & Aerospace Engineering Theses & Dissertations

A Kraft recovery boiler in a pulp-paper mill provides a means for recovery of the heat energy in spent liquor and recovery of inorganic chemicals while controlling emissions. These processes are carried out in a combined chemical recovery unit and steam boiler that is fired with concentrated black liquor and which produces molten smelt. Since the recovery boiler is considered to be an essential part of the pulp-paper mill in terms of energy resources, the performance of the recovery boiler has to be controlled to achieve the highest efficiency under unexpected disturbances.

This dissertation presents a new approach for combining …

Computational Modeling Of Airborne Noise Demonstrated Via Benchmarks, Supersonic Jet, And Railway Barrier, Moumen Idres

Mechanical & Aerospace Engineering Theses & Dissertations

In the last several years, there has been a growing demand for mobility to cope with the increasing population. All kinds of transportation have responded to this demand by expanding their networks and introducing new ideas. Rail transportation introduced the idea of high-speed trains and air transportation introduced the idea of high-speed civil transport (HSCT). In this expanding world, the noise legislation is felt to inhibit these plans. Accurate computational methods for noise prediction are in great demand.

In the current research, two computational methods are developed to predict noise propagation in air. The first method is based on the …

Nonlinear Constrained Optimizer And Parallel Processing For Golden Block Line Search, Duc T. Nguyen, Wilson H. Tang, Yeou K. Tung, Hakizumwami B. Runesha

Civil & Environmental Engineering Faculty Publications

Generalized exponential penalty functions are constructed for the multiplier methods in solving nonlinear programming problems. The non-smooth extreme constraint Gext is replaced by a single smooth constraint Gs by using the generalized exponential function (base a>1). The well-known K.S. function is found to be a special case of our proposed formulation. Parallel processing for Golden block line search algorithm is then summarized, which can also be integrated into our formulation. Both small and large-scale nonlinear programming problems (up to 2000 variables and 2000 nonlinear constraints) have been solved to validate the proposed algorithms.

Circulation, Vol. 6, No. 2, Center For Coastal Physical Oceanography, Old Dominion University

CCPO Circulation

Winter 1999 issue of CCPO Circulation featuring article "Identifying Different Flow Constituents in Estuaries"

Continental Runoff And Effects On The North Atlantic Ocean Subtropical Mode Water, Larry P. Atkinson, Chester E. Grosch

CCPO Publications

Interannual salinity variations in North Atlantic Subtropical Mode Water (STMW) are well known although the cause is less well understood. Attempts to model local salinity variation with local evaporation and precipitation have not been successful and some authors invoke advection of low salinity water as the cause. Examination of the STMW and North American river runoff data suggests that runoff may partly explain the salinity variations. It is known that low salinity water resulting from Mississippi River outflow is transported well past Cape Hatteras. Spearman Rank Correlation analysis and spectra and cross-spectra Fourier correlation analysis both show that river flow …

Warm Water Formation And Escape In The Upper Tropical Atlantic Ocean - 1. A Literature Review, Sang-Ki Lee, G. T. Csanady

CCPO Publications

We review current understanding of the warm water formation and escape process in the tropical Atlantic Ocean and point out the physical aspects of the process not yet fully explored. From this review, we found a need for a simple model capable of describing the first-order heat and mass balance in the tropical Atlantic Ocean. This line of work is continued in part 2 [Lee and Csanady, this issue]. Copyright 1999 by the American Geophysical Union.

The Biotech Century (Book Review), Philip A. Reed

STEMPS Faculty Publications

No abstract provided.

Elasto-Plastic Responses Of Buried Pipeline Systems Under Wave Propagation, Yuean-Chen Lau

Civil & Environmental Engineering Theses & Dissertations

The purpose of this research is to study the elastic and inelastic behavior of buried pipeline system under arbitrary seismic wave propagation. Both continuous and segmented pipes with joints and junctions are included. The surrounding soil is simulated by a series of elasto-plastic springs uniformly distributed longitudinally and laterally along the pipes. To the joints, elasto-plastic longitudinal springs and bilinear rotational springs are adopted. It is assumed that the pipes remain linearly elastic. The effects of soil liquefaction and fault movement are not considered.

Since the dynamic effect has been found to be negligible, a quasi-static analysis is adopted in …

Surface Resistance Measurements Of Superconducting Niobium Samples With A Triaxial Cavity, Paul Martin Boccard

Physics Theses & Dissertations

This experimental study has revealed and investigated many of the physical issues that affect accurate measurement of the surface resistance for small samples consisting of superconducting niobium films on copper substrates. It is believed that this work provides the groundwork for future research directed towards solving this important problem. Accurate measurement of surface resistance for such samples is needed to allow the rapid evaluation and optimization of the deposition parameters necessary for manufacturing low-loss superconducting niobium films.

A superconducting niobium triaxial cavity was investigated to determine its suitability for measuring the residual surface resistance of copper samples that were sputter-coated …

First Mover Advantage: An Industrial Buyer Behavioral Perspective, Howard G. Ling

Theses and Dissertations in Business Administration

Contemporary order-of-entry research has shifted from econometric investigations to research grounded in quasi-experimental and empirical consumer behavior studies. In the marketing literature, Carpenter and Nakamoto (1988), Kardes and Kalyanaram (1992), and particularly Alpert and Kamins (1992, 1994, 1995) have examined the role of consumer behavior as a potential explanation of first mover advantage. However, little or no research has been devoted to an understanding of pioneer advantage as it relates to industrial markets.

This dissertation investigated the effect of order of entry on the attitudes of industrial purchasing managers. Six major hypotheses were proposed to examine the cognitive beliefs, attitudes, …

Classification Of Participants Into Two Health Resource Utilization Groups By The Health Enrollment Assessment Review (Hear) Survey, Jody W. Donehoo

Health Services Research Dissertations

The study examined the ability of the Health Enrollment Assessment Review (HEAR) survey instrument to classify participants into one of two groups according to utilization of health resources anticipated in the following year. Developed by the U.S. Air Force, the HEAR survey is used worldwide by the Department of Defense for enrollees in TRICARE Prime, the military's adaptation of the HMO model of managed care. Individual HEAR reports are prepared for survey participants and their primary care providers in TRICARE Prime. Although it is currently administered worldwide to a majority of the 8.4 million health care beneficiaries of the Department …

The Effects Of Applied Technology Instruction On Mathematics And Science Achievement Of Eighth Grade Students, John D. Hammons

OTS Master's Level Projects & Papers

The problem of this study was to evaluate the effectiveness of he Grafton Middle School technology education program's interdisciplinary activities in improving math and science grades of its students.

A Study To Determine The Effect That A Local Recycling Program Had On The Amount Of Household Solid Waste That Was Disposed Of In The Carrollton, Virginia Area, Donald Aubuchon

OTS Master's Level Projects & Papers

The following research goals were established to provide guidelines to conduct research and answer the problem: 1. Identify the present amount of recycling that is being done in the Carrollton, Virginia area; 2. Identify the current amount of household solid waste that is being produced in the Carrollton, Virginia area; 3. Identify the specific types of solid waste that are being recycled; 4. Identify how successful the recycling program has been.

A Study To Determine Why Middle School Students Enrolled In Technology Education Classes, David Jr. Locklear

OTS Master's Level Projects & Papers

To answer this problem, the following goals were developed; 1. Determine why students take technology classes as an elective; 2. Determine what specific reasons attracted students to technology education.

A Descriptive Follow-Up Study Of Piedmont Virginia Community College Electronics Technology Graduates From 1995-1999, Mark S. Fitzgerald

OTS Master's Level Projects & Papers

The goals of this study were to answer the following questions: Did the students find employment (or earn a promotion) in an Electronics related career upon graduation? Did the students feel that the Piedmont Virginia Community College (PVCC) Electronics program provided them with an adequate level of workplace preparation? What aspects of the Electronics program could be changed to better prepare future students for the workplace?