Engineering Commons^™

Full-Potential Integral Solutions For Steady And Unsteady Transonic Airfoils With And Without Embedded Euler Domains, Hong Hu

Mechanical & Aerospace Engineering Theses & Dissertations

The integral equation solution of the full-potential equation is presented for steady and unsteady transonic airfoil flow problems. The method is also coupled with an embedded Euler domain solution to treat flows with strong shocks for steady flows.

For steady transonic flows, three integral equation schemes are well developed. The first two schemes are based on the integral equation solution of the full-potential equation in terms of the velocity field. The Integral Equation with Shock-Capturing (IE-SC) and the Integral Equation with Shock-Capturing Shock-Fitting (IE-SCSF) schemes have been developed. The IE-SCSF scheme is an extension of the IE-SC scheme, which consists …

Irish H & V News

Building Services Engineering

No abstract provided.

Structural Characterization Of A High-Temperature, Ionic Conducting Ceramic Using Perturbed Angular Correlation Spectroscopy, Gary L. Catchen, Michael Blaszkiewicz, Khalid Jamil, Dinesh K. Agrawal, Wayne Huebner, Herbert A. Mckinstry, Lorenz H. Menke Jr.

Materials Science and Engineering Faculty Research & Creative Works

Perturbed angular correlation (PAC) spectroscopy has been used to characterize several structural aspects of a high-temperature, ionic conducting ceramic, CaZr3.95Hf0.05P6O24. Hafnium was introduced into the material to provide the PAC probe nuclei, 181Hf/181Ta, which were located primarily at Zr sites. PAC measurements were made over a range of temperatures from 77 to 1180 K, and they have been analyzed and interpreted using several simple models. The distorted octahedral crystal field at the Zr site produced a (low-frequency) static electric quadrupole interaction which can be accurately described by the point-charge model. But, the temperature dependence of the associated electric field gradient …

A Simulation Study Of A Space-Borne Optical Disk Mass Memory System, Kenny G. Chen

Electrical & Computer Engineering Theses & Dissertations

Issues concerning space-borne applications of an optical disk mass memory system (ODMMS) are investigated through computer simulation. The simulation model is developed according to a current description of the ODMMS with certain application constraints. The results are examined in terms of system modularity, multi-user data rate buffering, disk module access, and read/write file management. The conditions and requirements for future disk controller designs are indicated in the simulation results.

The Effect Of Elastic Boundary Conditions On The Dynamic Response Of Rectangular Plates, Terry K. Brewer

Mechanical & Aerospace Engineering Theses & Dissertations

Natural frequencies and forced steady-state harmonic response for the vibration of uniform rectangular plates with edges elastically restrained against rotation and transverse translation are addressed. A single mode Rayleigh-Ritz solution is derived using functions that describe the normal modes of vibration of a beam whose ends are elastically restrained. The finite element solution is obtained for comparison. MACSYMA symbolic manipulation system is implemented as an aid to the mathematical rigor of the Ritz approach and NASTRAN finite element code is used to model the mechanical system. Comparisons are made to published results and the solutions of this study are found …

Large Planar Maneuvers For Articulated Flexible Manipulators, Li-Farn Yang

Mechanical & Aerospace Engineering Theses & Dissertations

An articulated flexible manipulator carried on a translational cart is maneuvered by an active controller to perform certain position control tasks. The nonlinear dynamics of the articulated flexible manipulator are derived and a transformation matrix is formulated to localize the nonlinearities within the inertia matrix. Then a feedback linearization scheme is introduced to linearize the dynamic equations for controller design. Through a pole placement technique, a robust controller design is obtained by properly assigning a set of closed loop desired eigenvalues to meet performance requirements. Numerical simulations for the articulated flexible manipulators are given to demonstrate the feasibility and effectiveness …

Self Consistent Model Of The Glow Discharge, Hao Chen

Electrical & Computer Engineering Theses & Dissertations

The strong spatial variation of the electric field intensity in the vicinity of the cathode of a gas discharge requires the use of microscopic methods to describe the nonequilibrium behavior of the electron dynamics in this region. A one-dimensional Monte Carlo code was developed. It allows one to obtain the distribution of the electron drift velocity and rate coefficients for a given electric field intensity in the cathode fall. The results of this calculation are used to find the density distribution of charged particles in this region and consequently, by means of Poisson's equation, a corrected electric field intensity. In …

A Comment On ‘Failure Modes Of Hybrid Composites …’, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper comments on an earlier paper on the failure modes of hybrid composites by Pitkethly and Bader, which appeared in the Carbon Fiber Conference issue. © 1988 IOP Publishing Ltd.

Bulletin - March, 1988, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A four page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

Stability Of Steady Cross-Waves: Theory And Experiment, Seth Lichter, Andrew J. Bernoff

All HMC Faculty Publications and Research

A bifurcation analysis is performed in the neighborhood of neutral stability for cross waves as a function of forcing, detuning, and viscous damping. A transition is seen from a subcritical to a supercritical bifurcation at a critical value of the detuning. The predicted hysteretic behavior is observed experimentally. A similarity scaling in the inviscid limit is also predicted. The experimentally observed bifurcation curves agree with this scaling.

Acuta Enews March 1988, Vol. 17, No. 3

ACUTA Newsletters

In This Issue

President's Message

Party Line

17th Annual Summer Conference

Potpourri

From the Board

Plan Now For San Diego

The University of British Columbia

The Other Side of T-1

Excessive Beam Deflections On The Ky-52 Bridge Over Dix River (Boyle-Garrard County Line), Theodore Hopwood Ii, Vishwas G. Oka, David Q. Hunsucker, James H. Havens

Kentucky Transportation Center Research Report

Upon rehabilitation, beams and deck of the Ky 52 bridge over Dix River were observed to have excessive deflections. An investigation of the problem included field inspections, structural analyses, and interviews with relevant KYDOH and other personnel.

Field measurements were made of the beam deflections. Those were compared to construction field measurements and dead-load calculations.

The beam deflection problem is attributed to 1) a failure to provide for sufficient camber in the beams to accommodate for construction dead loads, and 2) pre-existing sags in the beams when placed prior to casting the deck. Part of the deck deflection problem can …

Allocation Of Highway Costs And Revenues, Jerry G. Pigman, John A. Deacon

Kentucky Transportation Center Research Report

A continuing task related to highway financing is determination of the appropriate level of taxation for each class of highway user. Cost allocation in various forms has traditionally been the tool used to achieve an equitable assignment of user responsibility. Following is a summary of results from such a cost-allocation study undertaken by the University of Kentucky's Transportation Research Program. The objective of this study is to determine highway cost responsibility of various user classes and to assess revenues relative to costs under existing levels of taxation and under various alternatives considered in the 1988 legislative session.

Evaluation Of Procedures For Testing Aggregates, David Q. Hunsucker

Kentucky Transportation Center Research Report

This report summarizes findings of a research study conducted to evaluate aggregate testing procedures as related to aggregate soundness and durability. The objectives of the study were to determine a suitable replacement or modification of Kentucky's existing Sodium Sulfate Soundness Test for aggregates which would more accurately reflect in-service performance of concrete pavements and bridges, to correlate freezing and thawing durability data and other test data with sodium sulfate soundness data, and to develop a rational implementation criterion for use of new or modified testing procedures.

There were no observable correlations between the various test methods evaluated and the Sodium …

Hierarchical Discrete-Event Simulation On Hypercube Architecture, Roger D. Chamberlain, Mark A. Franklin

All Computer Science and Engineering Research

This paper presents model of hierarchical discrete-event simulation algorithm running on a hypercube architecture. We assume a static allocation of system components to processors in the hypercube. We also assume a global clock algorithm, with an event-based time increment. Following development of the performance model, we describe an application of the model in the area of digital systems simulation. Hierarchical levels included are gate level (NAND, NOR, and NOT gates) and MSI level (multiplexors, shift registers, etc.). Example values (gathered from simulations running on standard von Neumann architectures) are provided at the model inputs to show the effect of different …

Irish H & V News

Building Services Engineering

No abstract provided.

Harvester Guidance Control System, George B. Day V, Timothy D. Smith

Biosystems and Agricultural Engineering Faculty Patents

A guidance control system for a harvester or like machinery includes a steering linkage operatively connected to at least one ground engaging wheel. Harvester steering is controlled through the linkage by either an operator controlled steering wheel or a sensor responsive self-steering mechanism. The sensor responsive self-steering mechanism includes a guide assembly pivotally mounted to the harvester. The guide assembly includes a pair of laterally spaced, cooperating tines that define a path therebetween for plants being harvested. A sensor positioned on each tine senses the position of plants as they are harvested. A control circuit is responsive to the sensors …

Photodetector Arrangement For Measuring The State Of Polarization Of Light, Rasheed M.A. Azzam

University of New Orleans Patents

An apparatus and method for the measurement of at least one parameter of the state of polarization of a light beam is described. The apparatus includes only a photo detector and no other optical elements. Thedetector surface is partially specularly re?ecting and intercepts the light beam at an oblique angle of incidence. The absorbed fraction of incident radiation produces a cor responding electrical output signal that is detected and from which the at least one parameter of the state of polarization can be determined; The detector may also be rotated to modulate the electrical output signal to determine the elliptic …

Load And Resistance Factor Design Of Cold-Formed Steel Load And Resistance Factor Design Specification For Cold-Formed Steel Structural Members With Commentary, Ling-En Hsiao, Wei-Wen Yu, Theodore V. Galambos

CCFSS Library (1939 - present)

FOREWORD This progress report contains the following two parts: Part I: Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. i-101). Part II: Commentary on the Load and Resistance Factor Design Specification for Cold-Formed Steel Structural Members (pp. 103-148). The load and resistance factor design specification proposed herein is the revised version of the design recommendations prepared in September 1985 and submitted to American Iron and Steel Institute as Seventh Progress Report. This document was prepared according to the 1986 edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members. The selections of ϕ …

Load And Resistance Factor Design Of Cold-Formed Steel: Calibration Of The Aisi Design Provisions, Wei-Wen Yu, Ling-En Hsiao, Theodore V. Galambos

CCFSS Library (1939 - present)

In the design of steel buildings, the "Allowable Stress Criteria" have long been used for the design of cold-formed steel structural members in the United States and other countries.' In view of the fact that the mathematical theory of probability, which has been so successfully applied in other fields of engineering, would seem to be equally applicable to cold-formed steel design by providing a more uniform degree of structural safety, the "Limit State Design" method based on the probabilistic concept has been used in Canada and Europe for the design of cold-formed steel structural members.' In the United States, a …

Evaluation Of Stability And Rutting Potential Of Asphaltic Concrete Using Big-Stone Gradations, David L. Allen, Hossien Roghani

Kentucky Transportation Center Research Report

Considerable interest has been generated in recent years in using big stone gradations to reduce rutting and shoving in asphaltic concrete. This report documents mix design procedures and a laboratory testing program to determine the stability and rutting potential of a big-stone gradation. A series of creep tests was performed on a big-stone gradation and the results were compared to creep tests performed on a Class I base mixture. The big-stone mix average approximately 50 percent rutting potential as compared to the Class I base. One creep specimen of the big-stone mixture was compacted using polymer-modified AC-20 grade asphalt cement. …

Evaluation Of Ads Polyethylene Pipe, L. John Fleckenstein, David L. Allen

Kentucky Transportation Center Research Report

Construction and performance evaluations of ADS Polyethylene Pipe N-12 are presented. Construction procedures and visual inspection data are included. The pipe appears to be performing well.

Environmental Assessment Of Las Vegas Wash And Lake Mead Artificial Wetlands Demonstration Project, John R. Baker, R. M. Gersberg, U.S. Environmental Protection Agency

Publications (WR)

The effective use of artificial wetlands for treatment of municipal wastewater is well documented; however, design and economic data for artificial wetlands development are limited (Gersberg et al., 1984a). This is due partly to regional differences in climate, soils, and vegetation and partly to the desired waste treatment. As a result, specific treatment levels and cost benefits relative to the use of an artificial wetlands for a particular site cannot be evaluated adequately without a pilot demonstration project. Las Vegas Wash receives sewage effluent from the Las Vegas metropolitan area and has been designated as a wetlands community park. Las …

Long-Term Evaluation Of The Acoustic Emission Weld Monitor, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

The Kentucky Transportation Research Program conducted an extended 10- month evaluation of the Acoustic Emission Weld Monitor (AEWM) in a bridge fabrication shop. That device was used to detect welding flaws during typical production of butt-welds on flanges and webs used in steel bridges. A total of 153 welds were monitored.

AEWM test results were compared with visual inspection and double- blind results of conventional nondestructive testing routinely conducted on the welds. The AEWM did not miss any flaws detected visually or by nondestructive testing. Three AEWM flaw indications were confirmed by conventional nondestructive testing (radiography).

A large number of …

Review Of Work Zone Literature, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

A literature search was conducted with the objective of identifying sources of information related to safety in highway work zones. Included is an annotated bibliography of 165 references. From the references, a list of recommendations were made to improve safety in highway work zones. The recommendations were organized into the six categories listed below.

1. Flagging
2. Delineation
3. Traffic Control Devices
4. Accidents
5. Design
6. Policy

Lsim2 User's Manual, Roger D. Chamberlain, Mark N. Edelman

All Computer Science and Engineering Research

Lsim2 is gate/switch-level digital logic simulator. It enables users to model digital circuits both at the gate and switch level and incorporates features the support investigation of the simulation task itself. Lsim2 is an augmented version of the original lsim* with the addition of several new MSI-type components models. This user's manual describes procedures for specifying a circuit in lsim2, mechanisms for controlling the simulation, and approaches to modeling systems.

Automatic Interface Generations From Grammar Specifications, Steve B. Cousins

All Computer Science and Engineering Research

This paper presents a method for automatically generating user interfaces to programs. All possible legal strings of input to a moderately interactive program, taken together, specify the input language of that program. A grammar for such a language is fundamentally knowledge about the language, and that knowledge can be used to assist the program's user in constructing legal program input. The set of words which can appear next in an input sentence, the 'Next set', is defined and a technique for calculating it with a modified version of Prologs's Definite Clause Grammar parser is given. One type of interface this …

Plain Wire Fencing For Pastoral Lands, A Mcr Holm

Bulletins 4000 -

The need to fence for efficient livestock control was recognised early in the history of the pastoral industry in Western Australia. Fence design, materials and layout have all undergone many changes since the 1880s. Modern fences have 4 or 5 strands of high tensile light gauge wires with post spacings up to 50m, and strains up to 4000m. These modern fences contain less material and are faster to erect than traditional fences, yet they provide an equally good, if not superior, barrier. The happy coincidence of strength and cost effectiveness will be apparent through this manual.

Load And Resistance Factor Design Of Cold-Formed Steel Comparative Study Of Design Methods For Cold-Formed Steel, Ling-En Hsiao, Wei-Wen Yu, Theodore V. Galambos

CCFSS Library (1939 - present)

Allowable Stress Design is the current method used to design cold-formed steel structural members and connections. In this design approach, factors of safety are used to compute the allowable design stresses which are compared to the actual maximum stresses that will occur in the member during the life of the structure. In recent years, the Load and Resistance Factor Design (LRFD) method has been developed for the design of hot-rolled steel shapes and the design of cold-formed steel structural members. This method is based on probabilistic and statistical techniques to account for the many uncertainties involved with the actual design. …

Teaching In A Virtual Classroom : Volume 2 Of A Virtual Classroom On Eies : Final Evaluation Report, Computerized Conferencing & Communications Center, Starr Roxanne Hiltz

Computerized Conferencing and Communications Center Reports

A Virtual Classroom is a teaching and learning environment located within a computer-mediated communication system. As a teaching environment, it provides a set of tools, strengths, and limitations which are available to an instructor for delivering course materials and structuring learning experiences. Its characteristics are merely potentials, just as the empty classroom with its chalkboards and desks awaits the efforts and creativity of the instructor and the students to make it "come alive."

This is the second volume of the final research report on experiences with the prototype of a Virtual Classroom system constructed and operated on EIES, the Electronic …