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The Ellet Family And Riverine Warfare In The West--1861-1865, Jesse L. Chapman

History Theses & Dissertations

During the American Civil War the centuries-old concept of the naval ram as a military weapon was revived. The most active theater of battle for naval rams was the Western rivers. The Mississippi River in the vicinity of Vicksburg saw the first modern instance of ram fleet meeting ram fleet. To combat Confederate attacks on union vessels operating on the rivers, the Mississippi Marine Brigade was added to the Ram Fleet in 1863. This brigade was a combined force of infantry, cavalry, and artillery with naval transports which would land and attack at the first sign of Confederate activity. This …

Long-Term System Performance Of A Direct Expansion Solar Assisted Heat Pump, Majid Abazeri

Mechanical & Aerospace Engineering Theses & Dissertations

The long-term thermal performance of a direct expansion solar assisted heat pump is determined from the transient system simulation of the system. The system employs a bare collector which also acts as the heat pump evaporator. Of particular interest in this study is the

configuration in which the compressor and the collector area are properly matched from the long-term thermal performance viewpoint. This matching is achieved through continuous as well as two step compressor capacity modulation. In addition to examining the effects of compressor capacity modulation, the effects of various system parameters such as collector area„ storage volume, load temperature, …

Freshman Record, 1985, Old Dominion University

University Yearbooks

1985 issue of Freshman Record of Old Dominion University

Computer Aided Simulation Of A Heating, Ventilating, And Air Conditioning System In A Building, Sunil Shrikrishna Kulkarni

Mechanical & Aerospace Engineering Theses & Dissertations

The Godwin Life Science Building on the Old Dominion University campus presents an interesting problem in terms of energy conservation. The building is the maximum energy resource consumer on the campus, having a criterion value of 234 KBtu/sq.ft-year (2657 MJoules/sq. rneter-year). A Simplified Energy Analysis Method (ASEAM) loads and systems computer program was used to simulate the building and its heating, ventilating, and air conditioning (HVAC) plant in order to understand the building's high annual energy resource consumption rate, and to devise ways to overcome it. The main goal was to assess and propose energy conservation improvements to the existing …

The Direct Summation Of Totally Self-Checking Checkers, Stefean Andrew Fedyschyn

Electrical & Computer Engineering Theses & Dissertations

A new technique for reducing the complexity of designing Totally Self-Checking (TSC) checkers for m-out-of-n codes is presented. The method is based on the partitioning of the input variables into r classes, then partitioning the code groups generated into Z output partitions. Comparison with earlier results reveals improvements in design simplicity and logic and testing complexity.

This thesis also presents a new method of TSC checker design where a j-level m₁/n₁ code and a k-level m₂/n₂ code TSC checker are directly summed to form a max [j,k]-level (m₁ + m₂) / …

Groundwater Management By Linear Programming, Seungho Song

Civil & Environmental Engineering Theses & Dissertations

Three hydraulic optimization models are developed. These models combine the finite difference equations of two-dimensional groundwater flow in composite aquifers with various linear programming techniques. The hydraulic submodel employed in these hydraulic optimization models is so versatile that it accounts for time varying pumpage, leaky artesian conditions, a variety of boundary conditions, induced infiltrations from streams or rivers, and conversion from artesian to water table conditions. The objective of submodel 1 is to maximize the total hydraulic head from pumping wells at the end of a study period. The objective of submodel 2 is the same as submodel 1, but …

Effect Of Wall Temperature Control On Low-Speed Axisymmetric Body Drag, John C. Lin

Mechanical & Aerospace Engineering Theses & Dissertations

This paper presents results of a numerical study of the effect of wall temperature control on the low speed aerodynamic drag of axisymmetric bodies at turbulent Reynolds numbers and zero angle of attack.

Results for both skin-friction and pressure drag were computed for slender bodies using first-order viscous-inviscid interaction theory. Computations using boundary-layer theory were conducted to evaluate the effect of wall heat transfer on bluff-body separation control. Wall heat transfer with 100 percent surface coverage (for all bodies) as well as some partial surface coverage cases were investigated. The wall-to­ tota1-freestream temperature ratio was varied between 0.08 and 2. …

Investigation Of Flow Phenomena In A Repetitively-Pulsed Gas Flow Switch, Shivakumar Srinivasan

Mechanical & Aerospace Engineering Theses & Dissertations

A two-dimensional, unsteady numerical model for analyzing the characteristics of gas flowing through a gas blown spark gap switch has been developed. The computational model is governed by the conservation equations of mass, momentum and energy in an inviscid, non-conducting, perfect, compressible fluid. The governing equations have been solved by using MacCormack's finite volume technique. The effects of rapid gas heating and subsequent changes in the fluid properties of the gas are examined in the high-pressure spark gap switch. The gas temperature, expansion velocity, density and pressure are calculated as functions of time. Air is the dielectric flowing through the …

A Survey Of Burnout Among Dental Hygiene Educators, Sandra Boggs Ricks

Dental Hygiene Theses & Dissertations

A survey was conducted on 159 full-time dental hygiene educators in order to collect data on job satisfaction, morale, and perceived institutional/program effectiveness. Educators were chosen for the study by cluster sampling from two- and four-year accredited dental hygiene programs in the United States. The programs were selected at random from stratified groups according to type of institutional setting. Participants were asked to complete a questionnaire which contained four major sections: demographic data, job satisfaction, institutional/program effectiveness, and feelings related to their position. Findings were analyzed utilizing contingency tables and Chi-Square analysis. No attempt was made to establish a cause …

Numerical Experiments With The Quasigeostrophic Potential-Vorticity Equation, Peter L. Spence

OES Theses and Dissertations

A method is developed to model the circulation of a barotropic, 8-plane ocean under an imposed steady wind stress. The model includes the effect of both horizontal and vertical friction along with nonlinear advection of vorticity. Implementing the method involves solving the unsteady quasigeostrophic potential-vorticity equation using a compact finite difference scheme (Gatski, Grosch, and Rose, 1982).

Once developed, this model is used in four separate numerical experiments. In each experiment, a model ocean with an initial flow field is driven to a steady state solution. Vertical viscosity is held constant in the first three experiments while lateral viscosity is …

Tectonic Implications Of Late Tertiary Strata Exposed Along The Piankatank River, Eastern Virginia, Daniel Stephen Lane

OES Theses and Dissertations

Biostratigraphic analysis of Late Miocene and Pliocene strata along the Piankatank River in eastern Virginia exposes a juxtaposition of the Eastover and Yorktown Formations. This structure is situated on a NE trending alignment of geological, geomorphic, and geophysical features which run from southern Virginia to northern Delaware. Tectonic jointing in isolated sandstone bodies and fracture controlled drainage patterns provide further evidence of post-middle Pliocene tectonism in the region. The lateral spacing of this structure from the Stafford and Brandywine fault zones and other linear features on the Coastal Plain strongly implies that a structural similarity exists between the Piankatank structure …

Age Tracking Performance And The Measurement Of Workload By A Secondary Tasks, Manuel Francisco Diaz

Psychology Theses & Dissertations

The purpose of this study was to investigate age differences in tracking performance and in the amount of workload imposed by the tracking task. Twelve subjects between the ages of 18 and 22, and 12 subjects between the ages of 48 and 67 performed a serial, choice-reaction-time task alone and concurrently with a pursuit rotor tracking task. The choice reaction time task served as the secondary task and the pursuit rotor tracking task as the primary task. Primary task performance was measured by time on target and number of tracking errors, and the secondary task by choice reaction time and …

Design Of Infrasound-Detection System Via Adaptive Lmstde Algorithm, Camille S. Khalaf

Electrical & Computer Engineering Theses & Dissertations

A proposed solution to an aviation safety problem is based on passive detection of turbulent weather phenomena through their infrasonic emission. This thesis describes a system design that is adequate for detection and bearing evaluation of infrasounds. An array of four sensors, with the appropriate hardware, is used for the detection part. Bearing evaluation is based on estimates of time delays between sensor outputs. The generalized cross correlation (GCC), as the conventional time-delay estimation (TOE) method, is first reviewed. An adaptive TUt approach, using the least mean square (LMS) algorithm, is then discussed. A comparison between the two techniques is …

The Gift Of The Gods: The Impact Of The Korean War On Japan, John P. Bowen

Graduate Program in International Studies Theses & Dissertations

The Korean War was a benchmark in the modern history of Japan. It became a catalyst for political action, and the fountainhead of the "economic miracle" that raised Japan once again to a prominent position among nations. The Korean War helped solve many political problems, including the tricky question of a peace treaty. It confirmed Japan's commitment to a no-war constitution. It also permitted the Japanese government to relax the restrictions imposed by occupation authorities. The war created a fortuitous economic stimulus that permitted Japan to emerge from the recessionary period that followed World War II and to establish the …

I.G. Farben's Petro-Chemical Plant And Concentration Camp At Auschwitz, Robert Simon Yavner

History Theses & Dissertations

This study examines the history of the petrochemical plant and concentration camp run by I.G. Farbenindustrie (the dominant German chemical company during World War II) at Auschwitz to decide upon the degree of Farben’s involvement with Hitler and the Holocaust. The study traces the construction of the plant to determine Farben's participation at Auschwitz. The main sources consulted were the transcripts of the postwar Farben trial at Nuremberg along with eyewitness accounts of members of the prosecution staff. Based on the court's verdict, one might conclude that I.G. Farben operated in a state of coercion during the war and could …

Selection Of Sludge Conditioning Chemicals And Filter Media For Vacuum Filter Dewatering Of Sludge At The Atlantic Wastewater Treatment Plant, Douglas W. Fredericks

Civil & Environmental Engineering Theses & Dissertations

A literature review was conducted to determine the types of vacuum filter systems available for sludge dewatering, the characteristics of wastewater sludge which are important to dewatering, and the methods of sludge conditioning for vacuum filtration which are available. Capillary suction time and Buchner funnel tests were performed to determine the dewatering characteristics of sludge conditioned with ferric chloride and lime, polymer, polymer and lime, and polymer and incinerator ash. Filter leaf tests were performed to determine filter cake release characteristics of various conditioned sludge and the performance characteristics of several filter media. It was determined that ferric chloride and …

An Experimental And Analytical Investigation Of Friction Factors For Fully Developed Flow In Internally Finned Triangular Ducts, Hoshang Chegini

Mechanical & Aerospace Engineering Theses & Dissertations

Friction factors for fully-developed flow in triangular ducts with fins of various sizes are investigated for Reynolds numbers ranging from 150 to 90,000. Two triangular ducts having apex angles of 60 and 38.8 degrees are studied. Results are presented in the form of standard plots of friction factor as a function of Reynolds number. Friction factor values for the smooth triangular-duct cases are in good agreement with the existing results. For the finned-duct cases, the fully developed axial-velocity profiles in laminar flow are determined by solving the x-momentum equation iteratively by the Gauss-Seidel finite difference technique. The theoretically determined friction …

The Electrocortical Correlates Of Fluctuating States Of Attention During Vigilance Tasks, Stephen G. Cunningham

Psychology Theses & Dissertations

This study investigated the electrocortical correlates of attention. Sixteen subjects (seven females, nine males) engaged in a forty-minute target-detection vigilance task. In addition to the demands of the vigilance task, the subjects were asked to press a button during the vigilance task if they had experienced task-unrelated thoughts (TUTs) or daydreams. Continuous electroencephalograms (EEG) were recorded from the subjects during the entire task. During the vigilance task, task-irrelevant tones were presented every 2-4 seconds. Event-related potentials (ERPs) elicited by these tones were generated.

The task was divided into four ten-minute periods. The analysis of the performance data indicated performance decrements …

Combined Forced And Free Convection In The Trombe Wall Channel, Jim Ginchaun Huang

Mechanical & Aerospace Engineering Theses & Dissertations

A vertical channel connected by horizontal exit and entrance segments is simulated and represents a flow passage for a Trombe wall solar collector. The two-dimensional combined forced and free convection mode is investigated for the laminar regime. The vertical walls of the channel are maintained at a constant but different temperature while horizontal walls are insulated. A finite difference method using up-wind differencing for the non-linear convective terms and central differencing for the second order derivatives is employed to solve the governing differential equations for mass, momentum, and energy balances. The solution is obtained for stream function, vorticity, and temperature …

An Experimental And Analytical Investigation Of The Iosipescu Shear Test For Composite Materials, Barry Stuart Spigel

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical properties of composite materials under shear loading are difficult to determine. The Iosipescu Shear test, originally proposed for metals, has in recent years been applied to composites. It has the advantages of small specimen size, simple loading and a reasonably uniform shear stress in the test section.

The purpose of this work is to study the validity of the Iosipescu test method for measuring the shear modulus and shear strength of composites. Finite element analyses indicate that optimum specimen geometry and load locations depend upon the degree of orthotropy of the composite. Test results for a quasi-isotropic graphite/epoxy laminate …

Implementation Of Uniform Perturbation Method For Potential Flow Past Axisymmetric And Two-Dimensional Bodies, Tin Chee Wong

Mechanical & Aerospace Engineering Theses & Dissertations

The aerodynamic characteristics of potential flow past an axisymmetric slender body and a thin airfoil are calculated by using a uniform perturbation analysis method. The method is based on the superposition of potentials of point singularities distributed inside the body. The strength distribution satisfies a linear integral equation by enforcing the flow tangency condition on the surface of the body. The complete uniform asymptotic expansion of its solution is obtained with respect to the slenderness ratio by modifying and adapting an existing technique. Results calculated by the perturbation analysis method are compared with the existing surface-singularity-panel method and some available …

Block Encoding Of Speech Spectral Principal Components, James R. Holland Jr.

Electrical & Computer Engineering Theses & Dissertations

A Karhunen-Loeve series expansion was used to block encode speech spectral principal components as a function of time. Each of ten principal components was first obtained as a linear combination of 2© speech spectral band energies. Using a fixed block length of 10 frames (0.128 s), the K-L basis vectors were computed separately for various speakers for each principal component. In all cases the resulting basis vectors were essentially a set of discrete cosine basis vectors. Synthesis of speech from the block encoded parameters showed that very little information is lost with up to 70% data reduction. The block encoding …

Suboptimal Algorithms For Improvement Of Pipeline Through Insertion Of Delays, Sukhamoy Som

Electrical & Computer Engineering Theses & Dissertations

Pipelining is now widely used in the design of high speed processors in order to overcome the intrinsic speed limitations imposed by the technology. For a good performance and avoidance of internal conflicts, the concurrent operations within different subunits of a pipeline architecture should be properly scheduled This scheduling problem is known to be intrinsically difficult" and a member of the "NP complete class of problems. The aim of this thesis is to develop heuristic suboptimal algorithms whose execution time is a polynomial function of the number of items to be scheduled. Insertion of delay is used as a basic …

Triple Trigonometric Series And Their Application To Mixed Boundary Value Problems, Gordon Melrose

Mathematics & Statistics Theses & Dissertations

In this dissertation the author investigates some triple trigonometric series which occur in the solution of mixed boundary value problems in elasticity and potential theory. By choosing a suitable integral representation for the sequence of unknown constants, the problem is reduced to solving a singular integral equation of the first kind. Twenty four cases in which the integral equation can be solved in closed form are discussed in detail.

In later chapters, the application of triple trigonometric series to problems in physics and engineering is demonstrated and closed form solutions for the physical parameters of interest are obtained.

Studies On The Interference Of Wings And Propeller Slipstreams, Ramadas K. Prabhu

Mechanical & Aerospace Engineering Theses & Dissertations

The small disturbance potential flow theory is applied to determine the lift of an airfoil in a nonuniform parallel stream. The given stream is replaced by an equivalent stream with a certain number of velocity discontinuities, and the influence of these discontinuities is obtained by the method of images. Next, this method is extended to the problem of an airfoil in a nonuniform stream of smooth velocity profile. This model allows perturbation velocity potential in a rotational undisturbed stream. A comparison of these results with numerical solutions of Euler equations indicates that, although approximate, the present method provides useful information …

A 250-Kv Two-Pulse Modulator For The Gas Flow Switch Test Facility, David Michael Barrett

Electrical & Computer Engineering Theses & Dissertations

High-pressure spark gap switches are often used in pulsed power systems because of their high power capabilities. Unfortunately, these switches cannot be operated at high repetition rates because of the time required for the switch to recover. However, the recovery rate of a spark gap may be improved by flowing a gas through the interelectrode region so as to remove the hot gases and debris.

A test facility has been designed and constructed at Old Dominion University to evaluate the performance of gas-flow spark gap switches operating over a wide range of voltages and flow parameters. The facility consists of …

Research To Develop A Consensus Self-Evaluation Model Of National Norms Of Excellence For Alternating Cooperative Education Programs At Four-Year Colleges And Universities, Constance F. Brothers

Theses and Dissertations in Urban Services - Urban Education

The research described in this dissertation was conducted in response to an expressed need for the development of national norms of excellence for cooperative education programs in the United States in 1980. In academic year 1981-1982 a Delphi technique was used with 12 cooperative education experts, who identified 155 cooperative education program norms of excellence specifically for four-year alternating cooperative education programs.

In academic year 1982-1983, the 155 norms identified were transposed into a 90-item self-evaluation questionnaire which was field tested and sampled at 14 colleges and universities with alternating cooperative education programs in the United States. Of 900 college …

Admissions Criteria As Predictors Of Students' Successful Completion Of A Dental Hygiene Program, M. Linda Brown

Dental Hygiene Theses & Dissertations

The purpose of this study was to investigate the criteria used to select dental hygiene students and to determine the ability of these criteria to predict students' successful completion of a dental hygiene program. One hundred sixteen graduates of the certificate level dental hygiene program at Old Dominion University between 1971- 1981, inclusive, comprised the sample. The majority of the subjects were Caucasian females, ages 20 to 24. The admissions criteria examined were (1) Dental Hygiene Aptitude Test scores, (2) Scholastic Aptitude Test scores, (3) preadmission quality point average, (4) college chemistry quality point average, and (S) percentile rank in …

Shape Optimization For Elastic Hollow Bars In Torsion, Jahau Lewis Chen

Mechanical & Aerospace Engineering Theses & Dissertations

The problem of finding optimal cross-sectional shapes of elastic hollow bars in torsion is formulated and solved numerically. A variational formulation for the state equation is presented, and the material derivative of continuum mechanics is used for the shape design sensitivity analysis. Performance criteria include the bending stiffness, the torsional rigidity, and the weight of the bar. The existence of a keyway, an example of geometric irregularity, can be considered as well. The material can be either isotropic or anisotropic. The finite element method is used for the numerical solution of the variational state equation and is integrated into an …

Finite Element Thermal-Structural Analysis Of Cable-Stiffened Space Structures, Ajay Kumar Pandey

Mechanical & Aerospace Engineering Theses & Dissertations

Finite element thermal-structural analyses of cable-stiffened space structures are presented. A computational scheme for calculation of prestresses in the cable-stiffened structures is also described. The determination of thermal loads on orbiting space structures due to environmental heating is described briefly. Three finite element structural analysis techniques are presented for the analysis of prestressed structures. Linear, stress stiffening and large displacement analysis techniques are investigated.

The three techniques are employed for structural analysis of prestressed cable structures at different prestress levels. The three analyses produce similar results at small prestress. but at higher prestress differences between the results become significant. For …