Engineering Commons^™

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, April 1991, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Noise Generators For The Simulation Of Digital Communication Systems, Martina F. Schollmeyer, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

The generation of random numbers, having uniform and Gaussian distributions, with application to the time-domain simulation of communication systems is considered. The specific goal is to identify appropriate noise generation algorithms for use in system simulations for the determination of the symbol error probability of a digital communication system. Several methods of generating both uniform and Gaussian random numbers are examined. The algorithms considered were taken from those discussed in recent literature that appeared most appropriate for our problem. The algorithms were programmed in FORTRAN for use on a PC with math-coprocessor. Tests to evaluate the statistical properties of the …

Vapor-Liquid Equilibrium Data For The Nh3-H2o System And Its Description With A Modified Cubic Equation Of State, Thomas M. Smolen, David B. Manley, Bruce E. Poling

Chemical and Biochemical Engineering Faculty Research & Creative Works

New pressure-temperature-overall composition vapor-liquid equilibrium (VLE) data are reported for the ammonia-water system at five temperatures between 20 and 140 °C and up to 500 pela. These data have been converted to T-P-x data, and vapor-phase compositions have been calculated by means of a Rediich-Kwong equation of state modified to Include Peneloux's volume translation and a density-dependent mixing rule. In order to achieve agreement of calculated vapor-phase compositions with previous literature results, H was necessary to use different kij values In the vapor and liquid phases. © 1991, American Chemical Society. All rights reserved.

Diffraction Studies On Ni-Co And Ni-Cr Alloy Thin Films, A. R. Sethuraman, R. J. De Angelis, P. J. Reucroft

Nebraska Center for Materials and Nanoscience: Faculty Publications

Alloy films of Ni-Co and Ni-Cr of compositional ratios 1:1, 1:3, and 3:1 deposited by vapor deposition were studied by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). Results of TEM analysis on the Ni-Co alloy films indicated that the films were face-centered cubic (fee) in structure. XRD results confirmed the TEM observations. TEM analysis of Ni-Cr alloy films showed that the films were bodycentered cubic (bec) in structure. With increase in the Cr content more than 25%, the material contained a higher fraction of an amorphous phase. XRD studies provide limited information owing to the quasi-amorphous structure of the …

Development Of Turning Templates For Various Design Vehicles, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study was to develop the data necessary to produce the turning templates that would represent the minimum turning paths for critical design vehicles. This would include information concerning truck turning radii and offtracking for larger trucks with varying wheelbases operating in Kentucky. In order for the turning templates used for the various design vehicles to be based on the same procedure, data were produced tor design vehicles ranging from a passenger car to a combination truck with a 53 foot trailer. The simulation model used was the Truck Offtracking Model (TOM) and was developed by the …

Effect Of Acoustic Oscillations On The Burning Of Carbon, Vivek Lall

Master's Theses - Daytona Beach

This study is concerned with the investigation of the effect of oscillatory flow on the burning of carbon. This involves the study of two separate problems. The first is to obtain a solution for combustion of a carbon particle surrounded by a stationary gaseous film, and the second is to obtain a solution for combustion of the carbon particle subjected to acoustic oscillations. A computer program is developed to solve the governing equations of both problems. Comparison of the solutions to the steady and the oscillatory cases provides information on the effect of the oscillations on carbon particle combustion.

Various …

An Analytical Study Of The Effects Of Age And Experience On Flight Safety, Patrick C. Guide

Master's Theses - Daytona Beach

The purpose of this study was to determine whether there are any significant decreases in the safety and effectiveness of pilots by age 60. The data for this study came from records of general aviation accidents (i.e., for private pilots, commercial pilots, and air transport pilots), and airline accidents (Part 121). These accident data were acquired from many specialized aviation data banks; these include: NTSB, AOPA, FAA, and the COMSIS Research Corporation. The data were organized into groups according to the ages of the pilots-in-command responsible for the accidents. Groupings progress in five-year increments starting at 20-24, and ending with …

Q Improvement Of A 5.2 Ghz Te011 Cavity By Incorporating Y1Ba2Cu3O7-X, R. Joseph Leclear

Electrical & Computer Engineering Theses & Dissertations

Research is undertaken to apply high temperature superconducting material to improve the quality factor (Q) of a 5.2 GHz cylindrical resonant cavity. In particular, the approach is to electrophoretically deposit polycrystalline Y₁Ba₂Cu₃O_7-x (YBCO) on the conducting surface of the cavity cylinder. Spalling of the YBCO ceramic coating due to expansion and contraction of the cavity during sintering and testing is overcome by segmenting the cylinder. Results show that the Q of the cavity is increased over that of a copper cavity at temperatures below 60 K. At 20 K, improvement exceeds a factor …

Analytical Modeling And Simulation For Investigation Of A Digital Gas Filter Correlation Radiometer, Catherine P. Mcgowan

Electrical & Computer Engineering Theses & Dissertations

This thesis investigates a digital gas filter correlation radiometer called the Tropospheric Radiometer for Atmospheric Chemistry and Environmental Research (TRACER), which will be used to remotely measure carbon monoxide at three levels in the troposphere. The nadir-viewing radiometer measures the differential absorption of radiation through the atmosphere at 4.67@m and 2.33pm wavelengths. This thesis develops an analytical model of the TRACER measurement process to evaluate the effect of varying certain system parameters on the measurement. The independent sampling criterion and the response of linear systems to random signals are explained. A parametric simulation model is also developed to evaluate the …

The Breakdown Mechanism Of Hollow Cathode Discharge, Mai Tuyet Ngo

Electrical & Computer Engineering Theses & Dissertations

In a low pressure discharge, if the cathode incorporates a cylindrical or slit shaped hole, the discharge current can be several orders of magnitude higher than in one with plane parallel electrodes under the same pressure and voltage conditions. In this work hollow cathode discharges in Helium under the influence of variable parameters such as gas pressure, applied voltage, electrode gap spacing, external magnetic field, etc., are investigated by means of electrical and optical diagnostic techniques.

The results indicate that a hollow cathode discharge develops in two stages. The initial breakdown occurs along the longest straight path of the system, …

Signal Processing Methodologies For An Acoustic Fetal Heart Rate Monitor, Robert A. Pretlow Iii

Electrical & Computer Engineering Theses & Dissertations

Research and development is presented of real time signal processing methodologies for the detection of fetal heart tones within a noise-contaminated signal from a passive acoustic sensor. A linear predictor algorithm is utilized for detection of the heart tone event and additional processing derives heart rate. The linear predictor is adaptively "trained" in a least mean square error sense on generic fetal heart tones recorded from patients. A real time monitor system is described which outputs to a strip chart recorder for plotting the time history of the fetal heart rate. The system is validated in the context of the …

An Erasable Optical Memory Based On Stimulated Electronic Transition Concept, James D. Satira

Electrical & Computer Engineering Theses & Dissertations

Erasable optical memory systems with a high storage density and a large data transfer rate are required for many real time data acquisition systems such as those placed aboard NASA's space born platforms. A new concept for erasable optical memory involving stimulated electronic transitions (SET) will meet these requirements. The SET concept useful in erasable optical storage systems was demonstrated in MgS and SrS doped with Eu and Sm. The optical properties of these materials were studied. The reading and writing wavelengths for these samples were determined to be 950 and 514 nm respectively. The peaks of the emission spectra …

Finite Element Analysis Of Thermal Post-Buckling And Vibrations Of Thermally Buckled Composite Plates, Charles Clifton Gray

Mechanical & Aerospace Engineering Theses & Dissertations

The development of supersonic and hypersonic flight vehicles such as the High Speed Civil Transport and the National Aero-Space Plane has created an increased need for analysis of structures at very high temperatures. Bisplinghoff and Pian, Yang and Han, and Dokmeci and Boley have conducted experimental and analytical studies to determine the effect of elevated temperatures on the vibration characteristics of isotropic plates, Chen and Chen, and Meyers and Hyer have clone studies on thermal buckling and post-buckling of composite plates, respectively.

The thermal loads which will be imposed on the new high speed aircraft will be too great for …

Simulation Of 3-D Viscous Flow Around A Nozzle-Afterbody At High Speeds, Wendy B. Hoffman

Mechanical & Aerospace Engineering Theses & Dissertations

Turbulent shear flows at supersonic and hypersonic speeds around a nozzle-afterbody are numerically simulated and investigated. The specific application is for the flow around the nozzle-afterbody of a generic hypersonic vehicle. Accurate simulation of viscous, separating flows is not an easy task, and it is complicated by turbulence modeling concerns. A main objective of this study is to numerically simulate the afterbody flowfield while addressing the turbulence modeling problem. The viscous flow considered i~ this study is characterized by three-dimensional corner flows, shock boundary layer interactions, plume flow, shear layers, and cross-flow separations. Accurate simulation of this flow requires solution …

A Simulation Analysis Of The Usaf Commissary Customer Service Environment In Support Of Afcoms Store-Level Staff Sizing, Bruce H. Fritz Ii

Theses and Dissertations

This Thesis sought to determine the probable impact of the proposed Air Force Commissary Service (AFCOMS) manpower standard for customer service (manpower standard) upon commissary operating environments and to investigate the sensitivity of performance parameters within the customer service system. Specific problems addressed were: (1) Comparison of the cashier manpower requirements calculated by the proposed AFCOMS manpower standard to those determined by a simulation model under similar conditions; (2) Calculation of the expected mean and maximum waiting times in the commissary given the proposed standard; and (3) Determination of the sensitivity of customer waiting time performance measures to variations in …

Investigation Of Effects Of Nose Bluntness And Angle Of Attack On Slender Bodies In Viscous Hypersonic Flows, Ashwini Kumar Sehgal

Mechanical & Aerospace Engineering Theses & Dissertations

Hypersonic flows over cones and straight biconic configurations are calculated for a wide range of free stream conditions in which the gas behind the shock is treated as perfect. Effect of angle of attack and nose bluntness on these slender bodies in air is investigated extensively. The numerical procedures are based on the solution of complete Navier-Stokes equations at the nose section and parabolized Navier Stokes equations further downstream. The flow field variables and surface quantities show significant differences when the angle of attack and nose bluntness are varied. The complete flow field is thoroughly analyzed with respect to velocity, …

Development And Characterization Of Monoclonal Antisperm Antibodies: Potential For Contraception, Dilrowshan H. Haque

Theses and Dissertations in Biomedical Sciences

There is an expressed need to develop a greater variety of safe contraceptive methods which would find acceptance worldwide, particularly in developing countries. Immunization against spermatozoa might be such a method as judged by the accumulated evidence from studies on human females and in a number of female animal species.

Two extraction techniques were used for sperm membrane antigen isolation. The first technique involved NP-40 detergent for antigen extraction from human motile sperm and the second technique employed homogenized human testis for antigen extraction. Using these immunogens, sperm membrane-specific monoclonal antibodies (MAbs) were developed. When these antisperm MAbs were subjected …

Large-Amplitude Finite Element Flutter Analysis Of Composite Panels In Hypersonic Flow, Carl E. Gray Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

A finite-element approach is presented for determining the nonlinear flutter characteristics of two-dimensional isotropic and three-dimensional composite laminated thin panels using the third-order-piston, transverse loading, aerodynamic theory. The unsteady, hypersonic, aerodynamic theory and the von Karman large deflection plate theory are used to formulate the aeroelastic problem. Nonlinear flutter analyses are performed to assess the influence of the higher-order aerodynamic theory on the structure's limit-cycle amplitude and the dynamic pressure of the flow velocity. A solution procedure is presented to solve the nonlinear panel flutter and large-amplitude free vibration finite element equations. This procedure is a linearized updated mode with …

Maximum Likelihood Estimation For Distributed Parameter Models Of Large Beam-Like Structures, Ji Yao Shen

Mechanical & Aerospace Engineering Theses & Dissertations

Proposed large space structures have many characteristics that give an advantage to modeling their structural dynamics by a set of partial differential equations (PDE's). By far, the most effort put forth in studying system identification and control to date has been based on finite element models. Despite its acceptability, such lumped parameter models have inevitable deficiencies primarily because of their complexity. Both approaches are complementary and each should be used where it is most effective. But the fact is that the distributed parameter approach has not been developed to the level of maturity as for the lumped parameter approach.

Motivated …

Two-Dimensional Heat Loss From A Building Slab Including Convective Effects In Saturated Soil, William W. Rust Iii

Mechanical & Aerospace Engineering Theses & Dissertations

The heat loss from a building slab was investigated. The continuity equation, Darcy's Law and the energy equation were formulated to include the temperature dependence of viscosity and density of water. The governing equations and appropriate boundary conditions were transformed into dimensionless variables. A finite difference numerical scheme was constructed based on the Gauss-Seidel method by lines and solved iteratively in alternating directions. A correlation between the geometrical characteristics of the domain, the convective surface heating parameters, and the total nondimensional slab heat loss in two dimensions was discovered. Furthermore, the correlation was extended to three-dimensional slabs and produced good …

Kinematic Synthesis Of Deployable-Foldable Truss Structures Using Graph Theory, Dirk B. Warnaar

Mechanical & Aerospace Engineering Theses & Dissertations

A graph theoretic approach is applied to the conceptual design of deployable truss structures. The characteristics that relate to the inter-connectivity of the elements of a deployable truss structure can be captured in a schematic representation, called a graph. A procedure is presented that enables the exhaustive generation of these graphs for structures of any given number of nodes and links and which are foldable onto a plane or onto a line.

A special type of truss structures, called truss modules, is presented. Graphs of this class of structures form a subset of the graphs of truss structures. Two procedures …

Prediction And Control Of Asymmetric Vortical Flows Around Slender Bodies Using Navier-Stokes Equations, Tin-Chee Wong

Mechanical & Aerospace Engineering Theses & Dissertations

Steady and unsteady vortex-dominated flows around slender bodies at high angles of attack are solved using the unsteady, compressible Navier-Stokes equations. An implicit upwind, finite-volume scheme is used for the numerical computations.

For supersonic flows past pointed bodies, the locally-conical flow assumption has been used. Asymmetric flows past five-degree semiapex cones using the thin-layer Navier-Stokes equations at different angles of attack, freestream Mach numbers, Reynolds numbers, grid fineness, computational domain size, sources of disturbances and cross-section shapes have been studied. The onset of flow asymmetry occurs when the relative incidence of pointed forebodies exceeds certain critical values. At these critical …

Center For Computer And Information Sciences Master Of Science In Computer Science Spring 1991, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

A Modified Parallel Fault Simulator For Combinational Circuits, Shih-Ming Li

Masters Theses

The most commonly used model for fault analysis is called the "Stuck-At" model. With this model, a faulty gate input and/or output is modeled as Stuck-at-0 (s--a-0) or Stuck-at-1 (s-a-1). After a certain number of test vectors are applied to a network, the percentage fault coverage is computed. This computed value relates to the percentage of stuck-at faults detectable at the output. Various studies have been made to enhance the performance of fault simulators. In this paper, a modified parallel simulator MODPAR for combinational circuits is presented. A comparison of simulation results from MODPAR is made with that of SCIRTSS …

Removal Of Chlorine From Chlorine-Nitrogen Mixture In A Film Of Liquid Water, Sarwan S. Sandhu

Chemical and Materials Engineering Faculty Publications

In industry there are many examples of absorption of a gas with or without chemical reaction in the liquid phase. In physical absorption, a particular gaseous component is removed from a gas mixture due to its larger solubility in the liquid phase solvent. The removal of butane and pentane from a refinery gas mixture by a heavy oil in the liquid phase is an example of physical absorption. In absorption with chemical reaction, the gaseous component to be removed transfers across the gas-liquid interface due to a difference in the bulk chemical potentials or concentrations in the two phases. The …

An Improved Method For Online Calculation And Compensation Of The Static Deflection At A Robot End-Effector, Paul P. Lin, Hsiang-Dih Chiang, Xiu Xun Cui

Mechanical Engineering Faculty Publications

Traditionally, robotic deflection analysis for a low-weight robot has been performed based on an assumption that each link is treated as a cantilever beam, which leads to no angular deflection at a joint. In practice, a robotic intermediate joint is linearly and angulary deflected when a load is applied at the end-effector. It is found in this study that the additional link deflection resulting from the angular deflection of a robotic revolute joint substantially contributes to the end-effector's total deflection. This article presents an improved method via a combination of classical beam theory, energy methods and the concepts of differential …

Sedimentology Of The Bedford-Berea Sequence (Early Mississippian), Williams Field, Michigan, David Alan Balthazor

Masters Theses

The Berea Sandstone has produced in excess of 1.6 million barrels of oil in the Williams field since discovery in 1980. Seven lithofacies are identified from conventional core in the Bedford-Berea sequence. These facies are interpreted as deltaic deposits comprising prodelta (Bedford Shale), delta front, destructive marine shale, abandoned distributary channel-fill, interdistributary bay-fill, transgressive marine sandstone, and marine shale (Sunbury Shale) facies. Passive channel-fill facies truncate reservoir sandstone bodies and compartmentalize the field NW-SE across the trend of the northwestplunging anticline.

The two reservoir facies in the Williams field are the delta front and transgressive marine sandstones. The sandstone framework …

Channel Routing And Compaction: An Integrated Approach, Roshan A. Gidwani

Masters Theses

An attempt is made at integrating channel routing gnd compaction. A new gridless three-layer channel router based on an integrated approach to channel routing and compaction is presented. Routing is based on combined constraint graphs. Nets are selected from the input net list based on the criteria of ancestor and descendant weights in the combined constraint graphs. Compaction is done immediately after some nets are routed by using a via-segment graph. The router and compacter work hand-in-hand, i.e., the changes made by the compacter are available to the router, which enables the router to route more efficiently. Experimental results show …

Magnetic-Field Distributions In Zinc-Nickel Ferrite, T. A. Dooling, Desmond C. Cook

Physics Faculty Publications

The Mössbauer effect has been used to study the microscopic magnetic properties of the cubic microwave ferrite (Zn_0.41Ni_0.59)Fe₂O₄ at 300 K. The magnetically split spectrum is broad and unresolved due to the overlap of the hyperfine magnetic fields at the tetrahedral and octahedral sites. This is caused by a distribution of magnetic fields at each site. The distribution is especially large and asymmetric at the octahedral site and is due to the fact that the iron atoms at this site are influenced by the presence of both iron and zinc at the tetrahedral …

Simulator For Concurrent Processing Data Flow Architectures, Mahyar R. Malekpour

Electrical & Computer Engineering Theses & Dissertations

A software simulator capable of simulating execution of an algorithm graph on a given system under the Algorithm To Architecture Mapping Model (ATAMM) rules is presented in this thesis. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. Investigating the behavior and determining the performance of an ATAMM based system requires the aid of software tools. The ATAMM Simulator presented in this thesis is capable of determining the behavior, performance, and reliability of a system without having to build a hardware prototype. Case studies are performed on four algorithms to demonstrate the capabilities of …