Digital Commons Network^™

Goertler Instability In Compressible Boundary Layers Along Curved Surfaces With Suction And Cooling, Alok K. Verma

Mechanical & Aerospace Engineering Theses & Dissertations

The Goertler instability of the laminar compressible boundary layer flows along concave surfaces is investigated. The linearized disturbance equations for the three-dimensional, counter-rotating streamwise vortices in two dimensional boundary layers are presented in an orthogonal curvilinear coordinates. The basic approximation of the disturbance equations, that includes the effect of the growth of the boundary layer, is considered and solved numerically. The effect of compressibility on critical stability limits, growth rates, and amplitude ratios of the vortices is evaluated for a range of Mach numbers for Oto 5. The effect of wall cooling and suction of the boundary layer on the …

Continental Shelf Processes Affecting The Oceanography Of The South Atlantic Bight. Progress Report, 1 June 1980-1 June 1981, Larry P. Atkinson

CCPO Publications

(Introduction) In the past year we executed our largest field effort to date, GABEX-1. The vast amount of data gathered has now been reduced to workable form and we report on some of the first results in this report. The GABEX-1 measurements combined with other observations in the last year have greatly increased our understanding of the South Atlantic Bight during the spring transition period when the shelf goes from horizontal to vertical stratification.

This progress report contains selected reprints, drafts, and parts of technical reports that represent our work over the past three years.

A Study Of The Career Salience, Marriage/Family Plans And Sex-Role Identity Of Twelfth Grade Girls In Vocational And Academic Programs As Determinants Of Vocational Choice, Janet F. Dickinson

OTS Master's Level Projects & Papers

This research study will attempt to answer the following questions concerning senior girls at Poquoson High School: 1. Is there a significant difference in career salience of students in vocational programs and those in college preparatory programs? 2. Is there a significant difference in marriage/family plans of students in vocational programs and those in college preparatory programs? 3. Is there a significant difference in the sex-role identity of students in vocational programs and those in college preparatory programs?

A Study To Determine The Feasibility Of Offering A Vocational Education Course In Television Production At The Chesapeake Technical Center, Robert F. Head

OTS Master's Level Projects & Papers

The specific questions addressed by this study were: 1. What is the employment outlook in the television industry? 2. What is the level of student interest in taking a course in television production? 3. What other programs currently exist in television production in Virginia and the United States? 4.What equipment would be required for teaching a course in television production?

A Survey To Determine If The Goals Of Aiasa Are Being Met By Participating Aiasa Students, Hubert P. Rodriguez

OTS Master's Level Projects & Papers

The problem of this study is to determine if the goals of AIASA are being met by participating industrial arts students.

"Applied Values" And Its Perceptions At Paul D. Camp Community College, Michael J. Forrest

OTS Master's Level Projects & Papers

This study sought to identify perceptions of students that have taken a previous ethics course in "values", likewise and investigation of problems encountered prior to the commencement and upon the conclusion of such a course. Research questions central to the study were: 1. What aesthetic worth does such a program serve to occupational-technical students? 2. Does having a technologist as a member of the team of teachers (humanist) relieve non-traditional student anxieties in "Applied Ethics" courses?

Slip Dislocation Formation During Continuous Wave Laser Annealing Of Silicon, Helmut Baumgart

Electrical & Computer Engineering Faculty Publications

High-voltage electron microscopy (HVEM) has been used for the investigation of the defect structure in cw laser-annealed silicon. We report for the first time a (HVEM) analysis of the formation processes involved in the nucleation and glide of slip dislocations during epitaxial regrowth by cw laser annealing of ion-implantation damaged silicon layers. Based on the combined optical and HVEM observations a model of the dislocation generation and glide processes is presented.

Recommendations For Master's Level Programs In Computer Science: A Report Of The Acm Curriculum Committee On Computer Science, Kenneth I. Magel, Richard H. Austing, Alfs Berztiss, Gerald L. Engel, John W. Hamblen, A. A. J. Hoffmann, Robert Mathis

Computer Science Faculty Publications

The ACM Committee on Curriculum in Computer Science has spent two years investigating master's degree programs in Computer Science. This report contains the conclusions of that effort. Recommendations are made concerning the form, entrance requirements, possible courses, staffing levels, intent, library resources, and computing resources required for an academic, professional, or specialized master's degree. These recommendations specify minimum requirements which should be met by any master's programs. The Committee believes that the details of a particular master's program should be determined and continually updated by the faculty involved. A single or a small number of model programs are not as …

High Resolution Laser Absorption Spectroscopy Of Ozone Near 1129.4 Cm-1, Lawrence N. Majorana

Physics Theses & Dissertations

A Beer's Law experiment was performed with a tunable laser to determine self broadened line shape parameters of one infrared absorption ozone line in the v1 band for ten pressures from 0.26 to 6.29 Torr at 285K. SO₂ line positions were used for wavelength calibration. Line shapes were iteratively fitted to the Voigt function at a Doppler width of 29.54 MHz (HWHM) resulting in values for the integrated line• strength, ( S), of (0.144 +/- 0.007 ) x ·10^-20 cm-1/molecule cm-2, line center frequency, (υ_ο) of 1129.426 cm-1 and the Lorentzian contributions to half width, (α …

Sound Absorption In N2-H2O Gas Mixtures At Elevated Temperatures, Roger W. Meredith

Physics Theses & Dissertations

Sound absorption measurements were conducted in N₂ -H₂O gas mixtures at 297, 343, and 387 Kelvin to determine the location of the vibrational relaxation peak of nitrogen on the frequency/pressure, (f/P), axis as a function of humidity and temperature. At low humidities the best fit of the data is to a linear relationship between (f/P)_max and humidity (h) yields a slope of 1 .84 X 10⁴ Hz/ atm mole fraction at all three temperatures. The slope is the same as that reported by Zuckerwar and Griffin (2.00 X 10⁴ Hz/atm mole fraction) but is …

Thermodynamic And System Performance Analysis Of A Heat Pump That Employs A Two-Phase Flow Collector As Evaporator, Yu-Fang Chiang

Mechanical & Aerospace Engineering Theses & Dissertations

A thermodynamic model is developed to analyze the thermal performance of two phase flow solar collectors, The well-known equilibrium homogeneous theory is used to model the two phase flow in the solar collectors. The resultant set of coupled ordinary differential equations for saturated pressure and quality of working fluids in the collector tubes are solved by an iterative procedure using a fourth order Runge-Kutta method. The results are then applied to determine the thermal performance of a solar assisted heat pump which uses two phase flow collector as the evaporator, The results indicate that even with the use of less …

The Distribution Of Cesium-137, Copper, Lead And Zinc In Various Sedimentary Environments Of The James River Estuary, Virginia, Colin Stevenson Moy

OES Theses and Dissertations

Ten grab samples and eight cores were obtained within a short stretch of the James River estuary. The distribution of CU, Pb, Zn, Cs-137, organic carbon (TOC) and fine-grained sediments in various depositional environments were examined. Within the past quarter of a century, these measured parameters have been accumulating preferentially in the low energy environment (Burwell Bay). The inventory of Cs-137 in the cores was linearly related to the inventory of heavy metals and TOC. The concentrations of Cs-137 in the surface sediments vary linearly to those of the other parameters suggesting that Cs-137 may be used as a tracer …

Experimental Study Of Delta Wing Leading-Edge Devices For Drag Reduction At High Lift, Thomas Dwight Johnson Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

Future fighter aircraft requirements specify efficient supersonic cruise and high-g maneuverability at high lift. The slender delta wing meets the first requirement but has large lift induced drag increments at high lift. One method to alleviate the drag is to control the flow at the wing leading edge (LE) by means of small LE devices, so as to maintain locally attached flow to higher angles of attack and thus increase the level of aerodynamic thrust.

The devices selected for evaluation were the fence, slot, pylon-type vortex generator (VG), and sharp leading-edge extension (SLEE). These devices were tested on a 60° …

A Nonlinear Hybrid Vortex Method For Wings Having Side-Edge Separations, Li-Chuan Chu

Mechanical & Aerospace Engineering Theses & Dissertations

A Nonlinear Hybrid-Vortex method (NHV-method) has been developed for predicting the aerodynamic characteristics of wings exhibiting side-edge separations. The present method is a coupline between vortex-panel and vortex-line methods. In the near-field calculations, vortex panels are used while in the far-field calculat1ons, vortex lines are used.

The wing and its free-shear layers are divided into planar quadrilateral panels having first-order vorticity distribution. The aerodynamic boundary conditions and continuity of the vorticity distributions are imposed at certain nodal points on the panels. An iterative technique is used to satisfy these conditions to obtain the vorticity distributions and the wake shape as …

Feasibility Of Quasi-Random Band Model In Evaluating Atmospheric Radiance, Navin Mirakhur

Mechanical & Aerospace Engineering Theses & Dissertations

The use of the quasi-random band model in evaluating the upwelling atmospheric radiation is investigated. The spectral transmittance and total band absorptance are evaluated for selected molecular bands by using the line-by-line model, quasi-random band model, exponential sum fit method, and empirical correlations, and these are compared with the available experimental results. The atmospheric transmittance and up­ welling radiance have been calculated by using the line-by-line and quasi-random models and are compared with the results of an existing program called LOWTRAN. The results obtained by the exponential sum fit and empirical relations are not in good agreement with experimental results …

An Apparatus For Measuring The Thermal Conductivity Of Cast Insulation Materials, Christine A. Wilkins, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

A steady-state apparatus has been developed for measuring the thermal conductivity of cast materials. The design has employed a novel thermal symmetry arrangement which can permit total electrical isolation of the test material from its surroundings. © 1980 American Institute of Physics

Dr. Félix-Roland Moumié And The Revolution In French Cameroon, 1948-1960, Gregory Kurt Glassner

History Theses & Dissertations

This thesis is an examination of the life of Dr. Felix-Roland Moumie and his political movement, the Union des Populations du Cameroun (UPC). An early nationalist in French West Africa, Moumie fought for the independence of his country within the French colonial system, at the United Nations and through a lengthy guerrilla war. Moumie and the UPC will be examined in the context of other African movements, the decolonization of Africa and the United Nations Trusteeship system.

Natural Convection In Shallow Inclined Enclosures, Effendy Arif

Mechanical & Aerospace Engineering Theses & Dissertations

A two dimensional natural convective flow in a shallow inclined enclosure has been considered. A mathematical model has been developed to simulate the flow. The system of governing equations has been solved using finite-differencing techniques and the alternating direction implicit method.

The effect of the Raleigh number, the enclosure aspect ratio and orientation on the heat transfer and flow development have been studied by determining the Nusselt numbers and analyzing a number of contour maps of temperature and stream function fields, and velocity profiles. The Nusselt number has been found to increase with the Raleigh number, the enclosure aspect ratio, …

Coherence Between Wind And Current Events In A Nearshore, Shallow Water, Wave Dominated Environment, George Milton Hecker

OES Theses and Dissertations

Five days of observation were made of the current at four depths in a water depth of eight meters, and accompanying record of local wind one-half Kilometer from shore at the U.S. Army Corps of Engineers Coastal Engineering Research Center field facility at Duck, North Carolina beginning five May 1978. The current was measured with a state-of-the-art electromagnetic current meter having a 0.2-second response time and an accuracy of (+/-) 2 centimeters per second. At each depth a ten-minute record was made each hour with a sampling interval of one-eighth second. The frequency components of the record were analyzed and …

The Effect Of The Herbicide Metolachlor On Nutrient Levels In Zea Mays L., Tamsey Dawn Warren Ellis

Biological Sciences Theses & Dissertations

An investigation of the effect of metolachlor, a chloracetamide herbicide released for agricultural purpose during the Spring of 1977, on plant tissue levels of phosphorus, potassium, calcium and magnesium in juvenile sweet corn and the recovery rate of sweet corn exposed to metolachlor from any plant nutrient effects when the herbicide was removed.

An increase of metolachlor concentration caused a progressive reduction in growth (height and dry weight) of the leafy portion of juvenile sweet corn. At metolachlor concentrations of 0.16 ppm and higher pronounced stunting and twisting were observed in the plants.

There was a progressive reduction in the …

Effects Of Sleep Loss On Information-Processing In An Absolute Judgment Task As A Function Of Task Difficulty, Frieda O'Steen Carlton

Psychology Theses & Dissertations

The effects of 36 hours of sleep loss on information-processing were assessed in an absolute judgment task. Of the 24 subjects employed, 12 served in the sleep-loss (experimental) and control conditions, respectively. All subjects were tested individually for a total of ten sessions; the control group was tested on ten consecutive days, whereas the experimental subjects were tested every four hours over a 36-hour period of sleep loss, and at a recovery session following approximately 12 hours of rest and recovery. The task required subjects to make absolute judgments of the size of two small circles of light and to …

Eigensystem Assignment Using Singular Value Decomposition, Ronald Dean Alley

Electrical & Computer Engineering Theses & Dissertations

An interactive approach to computer-based control system design is formulated and presented. There are four key features to this approach. Singular value decomposition is used for several matrix operations, rather than Gaussian methods, for improved numerical accuracy. Dynamic memory allocation is implemented to reduce system core requirements for matrix storage. Interactive plant parameter modification is implemented to allow user interaction with the program~ reducing design time. Finally, disk input-output is minimized to increase response time.

This design system is demonstrated in examples in which distinct user specified eigenvalues are achieved, and eigenvectors close to a user specified set of eigenvectors~ …

Influence Of Nonequilibrium Radiation And Shape Change On The Flowfield Of A Jupiter Probe With Ablation And Mass Injection, Sundaresa Venkata Subramanian

Mechanical & Aerospace Engineering Theses & Dissertations

The influence of nonequilibrium radiative energy transfer and the effect of probe configuration changes on the flow phenomena around a Jovian entry body is investigated. The radiating shock-layer flow is assumed to be axisymmetric, viscous, laminar and in chemical equilibrium. The radiative transfer equations are derived under nonequilibrium conditions which include multi-level energy transitions. The equilibrium radiative transfer is calculated with an existing nongray radiation model which accounts for molecular band, atomic line and continuum transitions. The nonequilibrium results are obtained with and without ablation injection in the shock layer. The nonequilibrium results are found to be influenced greatly by …

Analytic And Experimental Studies Of A True Airspeed Sensor, Joseph Yao-Cheng Shen

Mechanical & Aerospace Engineering Theses & Dissertations

The objective of this study was to analyze and design a true airspeed sensor which will replace the conventional pitot-static pressure transducer. This sensor should have the following characteristics: the flow phenomenon is vortex procession, or the "vortex whistle", it should have no moving parts, and also is to be independent of temperature, density, altitude or humidity changes. This sensor has been designed mainly for small commercial aircraft with the airspeed up to 321.9 km/hr (200 mph).

In an attempt to model the complicated fluid mechanics of the vortex precession, three-dimensional, inviscid, unsteady, incompressible fluid flow was studied by using …

The Carter Administrative Elite: A Background Analysis, Susan Adomaitis Armstrong

Institute for the Humanities Theses

This study is an inter-disciplinary analysis of the backgrounds of the Carter administrative elite. Various theories of political science, public administration, and ethics are presented in relation to Jimmy Carter's appointees. A background composite is presented of the elites' education, career before government service, age, sex, and geographic region of birth and socialization. Information about the elites was obtained from biographical listings, and was stored and processed by an electronic data processing system.

The Carter administrative elite has included persons who have been named to positions that do not maximize their experiences and qualifications in the most appropriate manner. This …

The Retention And Maintenance Of An Information Processing Skill, Jerry Willard Hedge

Psychology Theses & Dissertations

In the performance of most skilled activities, there are definite limits to the proficiency attainable by an individual. These limits and how they affect the retention and maintenance of a skill are of major interest to performance-- assessment research. While much is known about verbal and motor skill retention, very little research has focused on the long~term retention and maintenance of information processing skills. The purpose of the present investigation was to determine the extent to which the information processing skills involved in a typical choice reaction time (CRT) task are retained and maintained over periods of two to eight …

The Significance Of Peel Stresses In Cyclic Debonding, Richard A. Everett Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

One of the possible failure modes in adhesively bonded joints is cyclic debonding -- progressive separation of the adherends by cyclic failure of the adhesive bond. In this study cyclic debonding in an adhesively bonded crack-lap shear specimen has been investigated by means of a linear elastic finite-element analysis and a series of constant­ amplitude axial fatigue tests. The primary purpose of this study was to test the hypothesis that cyclic debonding is due largely to tensile peel stresses in the adhesive.

The results of this study have indicated that not all of the tensile peel stresses in the adhesive …

Attitudes Of Students In Selected Virginia Colleges And Universities Related To Death And Dying, Jacqueline J. Rochele

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to determine the attitudes toward death and dying of college students in selected colleges and universi­ties in Virginia. The purpose was to identify attitudinal differences relating to the characteristics of sex, race, age, religious preference, degree of religiosity, socio-economic area, income level, marital status, political viewpoints, imminent personal death, and personal death experience.

The Complete Inventory Price Death Attitude Scale was administered to 886 college students during the 1979-80 academic school year. Data were statistically analyzed by the Discriminant Analysis Technique and the Cattell Coefficient of Profile Similarity.

Data were analyzed in terms of …

Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne

Biological Sciences Theses & Dissertations

Macrobenthic invertebrates of an industrialized seaport ecosystem were studied seasonally from October, 1977 through July, 1978. Five stations were selected along the Southern Branch of the Elizabeth River, Virginia. The stations ranged from an area of heavy industrialization to a non-urbanized environment. At each station, bottom water was measured for salinity, temperature, dissolved oxygen, and pH. Within each sampling area, macrobenthic infauna! invertebrates were collected from in and out of channel sites along with sediment samples for various types of physicochemical analysis.

Community structure was spatially homogeneous at station sites and throughout the stations along the River. Slightly acidic pH …

A Dimensionality Reduction Algorithm For The Karhunen Loeve Transform, Salomi T. Charalambous

Computational Modeling & Simulation Engineering Theses & Dissertations

The Karhunen Loeve Transform has conclusively been shown to be the optimum data compression algorithm for signals belonging to the same second order stationary process. Consequently, researchers have been searching for a fast implementation for the transform. Fast imple­mentation methods similar to those developed for other orthogonal transforms are generally not applicable to the Karhunen Loeve Transform (KLT). Also, since the basis vectors composing the transformation matrix of the KLT are the eigenvectors of the covariance matrix of the input process, they must be computed first. The research re­ ported here is an attempt to reduce the dimensionality of the …