Engineering Commons^™

The Effects Of The Aging Process On The Mechanical Properties In Al-Cu-Li(2195) Alloy, Michael Abernathy

Electronic Dissertations and Theses

The Alumniurn-Copper-Lithi arn (Al-C u-Li) alloy s are used as aero space materi als du e to thei r low den sity , hig h modulus of elasticity, good resistance to fatigue crack propagation , and excelle nt cryogenic properties. In the current experime nt, Al-Cu-L i (2 195) allo y is se lected to study the effect of the ag ing process on mechanical propertie s. The 2 195 all oy in sheet form is supplied by Lockheed-Marti n, New Orleans. The as-received 2 195 alloy sheet is solution-treated at 5 10 ° C for one hour followed by …

Acuta Enews May 1997, Vol. 26, No. 5

ACUTA Newsletters

In This Issue

Slate of Nominees Approved

Be a Moderator of Monitor at ACUTA's 26th Annual Conference

Board Report

Univ. of Delaware to Host ACUTA Mid-Atlantic & New England Local Event

Dues Notices Mailed

Welcome Melanie

ACUTA Committees at Work

Spotlight

DC at a Glance

Regulation of BOC Long Distance Services Revised

Welcome New Members

Solar Water Heating: A Question And Answer Primer, Florida Solar Energy Center, David L. Block

FSEC Energy Research Center®

Solar water heating is a technology that every homeowner can use to save dollars on utility bills. Questions most frequently addressed to the Florida Solar Energy Center (FSEC) about solar water heating are answered below. Please note that many replies are general and more explanation may be required for those with individual questions. For additional information, contact the FSEC

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 5, May 1997, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Freezing Point Mobile Munitions Assessment Sytem: Thermal Chamber Redesign, Sara Gifford, Preston Harris

Undergraduate Honors Capstone Projects

The Army is actively investigating non-intrusive methods to identify six chemical weapons agents. The chemical munitions in question are often found scattered across military bases and other facilities. These non-stockpile munitions are specifically targeted for identification using the mobile munitions assessment system. This program is being administered by the Idaho National Engineering Laboratory.

Solar Water Heating Options In Florida, Florida Solar Energy Center, John Harrison

FSEC Energy Research Center®

This document is intended to acquaint Florida's general public with typical methods of heating household water by means of the sun. The types of solar systems discussed are pumped (both direct and indirect), thermosiphon and integral collector storage.

Cr9000 Measurement And Control System Pcmcia-Ata Software Device Interface, Ryan Jon Soulier

Undergraduate Honors Capstone Projects

Many industries have a need for high speed data collection of a large amount of data. For example, the auto industry extensively tests vehicles for resistance to stress, temperature, and moisture. Campbell Scientific, Inc. (CSI) has built the CR9000 measurement and control system that fills this need by being able to measure up to 252 separate sensors at a sustained rate of up to ten thousand samples per second.

The CR9000 system lacks efficiency because it has only a small, fixed amount of memory and is capable of recording data only for a short period. Older devices designed by CSI …

Optimizing Conjunctive Use And Groundwater Yield, Richard C. Peralta, Rahman Rahimzadegen, Narendra K. Tyagi

Civil and Environmental Engineering Faculty Publications

Advances in computer power and mathematical optimization procedures can improve planning and developing sustainable irrigation systems. Simulation and optimization models can help plm1 groundwater and conjunctive use strategies to best achieve management goals while satisfying mm1agement a11d physical constraints. Simulation/optimization models that couple calibrated flow and transport simulation models with optimization algorithms can help design the best water management strategies. Mm1agers can be relatively sure that the groundwater system will respond acceptably when appropriate procedures are employed to develop the water management strategies. Presented case studies illustrate situations in which developed strategies simultaneously address conflicting management goals such as: maximizing …

Structural Design Of A Crashworthy Energy Absorbing Passenger Seat For A Large Transport Aircraft Using Large Displacement, Nonlinear Material Finite Element Analysis, Javier Fuentes

Master's Theses - Daytona Beach

Federal Aviation Regulations certification criteria for transport aircraft seats require performing dynamic tests using anthropomorphic test dummies. Floor decelerations of the tests are 16g forward with the seat tracks misaligned by up to 10 degrees and 14g downward at a pitch angle of 30 degrees. In this project the dynamic response of the passenger/seat/restraint system is modeled using nonlinear finite element analysis. The interference between a dummy model and the seat is modeled using a contact interaction algorithm. This algorithm did not converge and multiple-point constraints were used to transfer the dummy's inertia load. This approach was validated with the …

Bulletin - May, 1997, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

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

Evaluating The Feasibility Of An Intermodal Transportation Facility In Chattanooga, Murugan Auruvankulam-Palani

Masters Theses and Doctoral Dissertations

This research develops a mathematical model based on linear programming techniques to evaluate the feasibility of developing an intermodal transportation facility in Chattanooga. Transportation resources in and around Chattanooga were studied, and the opportunities available for developing business by a transportation facility are analyzed. Large quantities of goods are shipped in and out of Chattanooga by trucks in either trailers or containers. In order to transfer goods in container or trailer from one mode of transportation to another, specific handling equipment is needed. Mobile cranes present in some transportation terminals in Chattanooga can transfer goods in small units only, but …

The Synthesis, Characterization, And Cell Seeding Of A Collagen/Hydroxyapatite Porous Scaffold For Treatment Of Osseous Defects, Kim Rachel Patterson

All Theses

The need for finding a bone graft substitute stems from the fact that approximately 200,000 bone grafting procedures are performed annually in the U.S. alone. Although biological grafting options (i.e. autografts & allografts) exist, they do suffer from inherent problems. These include limited resources, costly processing, and potential for pathogen transfer. Thus, investigators have sought synthetic alternatives.

The objective of this research was to utilize hydroxyapatite (HA) and collagen, both analogues to the major constituents of bone, to fabricate an optimal synthetic osteoconductive/osteoinductive bone scaffold. Current attempts by other investigators to combine the two materials have been met with some …

Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Multimedia applications are sensitive to I/O latency and jitter when accessing data in secondary storage. Transparent adaptive prefetching (TAP) uses software feedback to provide multimedia applications with file system quality of service (QoS) guarantees. We are investigating how QoS requirements can be communicated and how they can be met by adaptive resource management. A preliminary test of adaptive prefetching is presented.

Mechanism Of Anomalous Photoinduced Transient Current Peak In Amorphous Silicon Thin-Film Transistor, M. H. Chu, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

The photoinduced transient current from an amorphous silicon thin-film transistor is computed and the mechanism described in terms of trap-state filling dynamics. The direction of the current flow and the location of the transient peak depends strongly on the distributions of donorlike and acceptorlike trap states in the neighborhood of the dark Fermi level. We show that the transient current can flow in the same direction as in the crystalline transistor, as well as in the opposite direction. There is also an interesting cross-over behavior in which the transient current flows out of the drain terminal as a pulse of …

Training Strategies For Critic And Action Neural Networks In Dual Heuristic Programming Method, Christian Peter Paintz

Dissertations and Theses

This thesis discusses strategies for and details of training procedures for the Dual Heuristic Programming (DHP) methodology. This and other approximate dynamic programming approaches (HDP, DHP, GDHP) have been discussed in some detail in the literature, all being members of the Adaptive Critic Design (ACD) family. The example applications used here are the inverted pendulum problem and a fully nonlinear constant velocity bicycle steering model. The inverted pendulum has been successfully controlled using DHP, as reported in the literature. This thesis suggests and investigates several alternative D HP training procedures and compares their performance with respect to convergence speed and …

Evaluation Of Two-Dimensional Hydraulic Modeling In A Natural River And Implications In Instream Flow Assessment Methods, Karl L. Tarbet

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Logan River was used as a study site to assess the capabilities of two-dimensional depth-averaged hydraulic modeling in the x-y plane of a natural river for use with instream flow studies. Data were collected to spatially represent the study reach with depth, velocity, northing, easting, elevation, and substrate values using a total station and electronic velocity meter. Computational finite element meshes were generated using four different density levels of geometry data to examine the relationship between field data density and computational mesh on geometry errors. Geometry errors were found to be related to smoothing effects, which removed complex channel …

Predicting Resistance And Stability Of Vegetation In Floodplains, David E. Werth Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To calculate flow or depth in a waterway, it is necessary to accurately determine the flow resistance. Past research has made considerable progress in predicting the roughness of nonvegetated uniform channels based on both theoretical and experimental investigations. However, to determine the flow resistance associated with vegetated compound flow channels and floodplains, the effects of the vegetation must be considered.

Recent advancements have led to greater understanding of the effects of partially submerged uniform vegetation in a waterway. However, to accurately determine flow resistance, it is imperative that the effects of both submerged and partially submerged vegetation be taken into …

A Summary Of Highway Revenues, Expenses, And Distributions: 1987 Through 1996, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This report shows the history of receipts, expenses and distributions of revenues that provide funding to all local governments for highway, road and street work.

The Structure And Electrical Properties Of Srce0.95yb0.05o3 Thin Film Protonic Conductors, Igor Kosacki, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The results of a study of the structure and electrical properties of SrCe0.95Yb0.05O3 thin film protonic conductors are presented. Dense SrCe0.95Yb0.05O3 thin films (∼1000 nm) with grain size in the 30-70 nm range were obtained on Si- and Al2O3-substrates using a polymeric precursor spin coating technique. The electrical conductivity of these thin films has been studied as a function of temperature and correlated with the microstructure. The thin films showed higher electrical conductivity than dense sintered polycrystalline SrCe0.95Yb0.05O3 specimens which had grain size in the micrometer range. This electrical conductivity enhancement has been attributed to the influence of interfacial grain …

Tillage Effects On Soil Erosion Potential And Soil Quality Of A Former Conservation Reserve Program Site, John E. Gilley, J. W. Doran

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study was conducted to determine the effects of tillage on soil erosion potential and soil quality characteristics of a former Conservation Research Program (CRP) site. Following tillage, the study area in northern Mississippi was maintained in a fallow condition for nine months. Soil loss from simulated rainfall events was minimal on recently tilled plots and an adjoining, undisturbed CRP area. In contrast, soil loss from the former CRP site which had been tilled nine months previously was similar to values obtained before the CRP program when the area had been cropped for several years. Tillage and over-winter fallowing caused …

Super-Heterodyne C-Probe Design And Implementation, Scott A. Heritsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Modern advances in chip design and implementation have provided atmospheric scientists with the tools needed to advance the evolution of atmospheric probes, especially the impedance probe. The impedance probe measures the in-phase and out-of-phase components of the antenna's current with respect to the applied sinusoidal steady-state voltage. Through the integration of super-heterodyne circuitry with previous impedance probe designs, I was able to transfer the in-phase and out-of-phase components of an antenna's impedance in a plasma from 3 MHz to 23.25 KHz. By reducing the frequency of the information signal, it was easier to detect the in-phase and out-of-phase components. The …

On-Line Cartesian Trajectory Control Of Mechanisms Along Complex Curves, Edward Red, Zhaoxue Yang

Faculty Publications

New methods have been developed to control a mechanism's realtime Cartesian motion along spatially complex curves such as Non-Uniform Rational B-splines (NURBS). The methods dynamically map the critical trajectory parameters between parameter space, Cartesian space, and joint space. Trajectory models that relate Cartesian tool speeds and accelerations to joint speeds and accelerations have been generalized so that they can be applied to most classes of robots and CNC mechanisms.

Secondary Dark Rings Of Internal Conical Refraction, Karl F. Warnick, David V. Arnold

Faculty Publications

This paper treats the phenomenon of internal conical refraction, in which a narrow beam propagating along an optical axis of a biaxial anisotropic medium spreads into a hollow cone. An expression is obtained for the intensity distribution produced by conical refraction that predicts additional fringes concentric to the well known Poggendorf dark ring for certain propagation distances and beam widths.

Closed Form Solution Of The Wave Equation For Piles, Don C. Warrington

Masters Theses and Doctoral Dissertations

This thesis details the research into the one-dimensional wave equation as applied to piles used in the support of structures for civil works and driven using impact equipment. Since the 1950's, numerical methods, both finite difference and finite element, have been used extensively for the analysis of piles during driving and are the most accepted method of analysis for the determination of driving stresses, dynamic and static resistance of piles. In this thesis the wave equation is solved in a relatively simple closed form without recourse to numerical methods. A review of past efforts to solve the wave equation in …

Testing Of Solid Rocket Propellants With An Ultrasonic Transducer, Bryan Rasmussen

Honors Capstone Projects and Theses

No abstract provided.

Uptake And Metabolism Of Atrazine By Poplar Trees, Joel Gerard Burken, Jerald L. Schnoor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hybrid Poplar Trees Can Uptake, Hydrolyze, and Dealkylate Atrazine to Less Toxic Metabolites. in Whole Plant Studies, the Parent Compound Atrazine and 14C Ring-Labeled Metabolites Were Extracted from Poplar Tissues and Analyzed Via High-Pressure Liquid Chromatography (HPLC) with UV and Radiochromatographic Detectors in Series. the Concurrent Separation and Identification of These Metabolites Has Not Been Previously Reported in Higher Plants for Phytoremediation Applications. Unidentified Metabolites Were Also Detected. Metabolism of Atrazine Occurred in Poplar Roots, Stems, and Leaves and Became More Complete with Increased Residence Time in Tissues. in Poplar Cuttings Exposed to Atrazine for 50 Days, the Parent Compound …

Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, Min Li, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Subcellular modeling of thin slots in the finite-difference time-domain (FDTD) method is investigated. Two subcellular algorithms for modeling thin slots with the FDTD method are compared for application to shielding end osures in electromagnetic compatibility (EMC). The stability of the algorithms is investigated, and comparisons between the two methods for slots in planes, and slots in loaded cavities are made. Results for scattering from a finite-length slot in an infinite plane employing one of the algorithms are shown to agree well with published experimental results, and power delivered to an enclosure with a slot agree well with results measured for …

Roadway Related Tort Liability And Risk Management: 4th Edition, Daniel S. Turner, Kenneth R. Agent

Kentucky Transportation Center Research Report

This training material has been prepared to address the tort liability problems faced by the Kentucky Transportation Cabinet and Kentucky local governments. The workbook defines the problem by reviewing the national picture of growing numbers of suits and escalating financial losses from suits against highway agencies.

The workbook also sets out solutions, and reviews actions which can decrease the exposure of highway agencies to these suits. This risk management concept is emphasized throughout the workbook.

Bs News

Building Services Engineering

No abstract provided.

A Robust Unit Commitment Algorithm For Hydro-Thermal Optimization, Chao-An Li, Chung-Li Tseng, E. Hsu, R. B. Johnson, A. J. Svoboda

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper presents a unit commitment algorithm which combines the Lagrangian relaxation (LR), sequential unit commitment (SUC), and optimal unit decommitment (UD) methods to solve a general hydro-thermal optimization (HTO) problem. The authors argue that this approach retains the advantages of the LR method while addressing the method''s observed weaknesses to improve overall algorithm performance and quality of solution. The proposed approach has been implemented in a version of PG&E''s HTO program, and test results are presented.