Engineering Commons^™

Sept 1999, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Director's Report Curator's Report Friend's Letterhead and Logo

The Weights Of Various Features In The Magnetic Spectra Of Cuprates, G. Aeppli, S. M. Hayden, Pengcheng Dai, Herbert A. Mook, R. D. Hunt, T. G. Perring, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

We review briefly the magnetic fluctuation spectra, obtained by neutron scattering, of the high temperature superconductor YBa₂Cu₃O_6.6 (T_c = 62.7 K). The resonance at 34 meV is the most prominent spectral feature in the superconducting state. Even so, its net weight accounts for a mere 1% of the total squared moment expected for planar Cu₂₊ ions. For context, we also provide a discussion of the spectral weights associated with the magnetic order and spin waves in two-dimensional S = 1/2 Heisenberg antiferromagnets.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 7, September 1999, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Acuta Enews September 1999, Vol.28, No. 9

ACUTA Newsletters

In This Issue

What's Hot on Your Campus?

Developing Collaborative Relationship

ACUTA EVENTS

DC Update

Pipeline Comes to Appalachia

Board Report

ACUTA Fall Seminars

Patricia Todus Named Director-at-Large

Welcome New Members

Positions Available

Pesticide Residue Regulation: Analysis Of Food Quality Protection Act Implementation, Linda-Jo Schierow

RISK: Health, Safety & Environment (1990-2002)

Dr. Schierow discusses the effects of a recent statute on food safety.

The Impacts Of Using A Safety Compliance Standard In Highway Design, Paul J. Ossenbruggen

RISK: Health, Safety & Environment (1990-2002)

Dr. Ossenbruggen introduces an algorithmic method to objectively test and evaluate safety in the highway design process.

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960's. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …

The Conference Proceedings Of The 1999 Air Transport Research Group (Atrg) Of The Wctr Society, Volume 3, Anming Zhang, Brent D. Bowen, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 99-7

The Conference Proceedings Of The 1999 Air Transport Research Group (Atrg) Of The Wctr Society, Volume 4 , Anming Zhang, Brent D. Bowen, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 99-8

Flight Physician - September, 1999, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

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

Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Applications with real-rate progress requirements, such as mediastreaming systems, are difficult to deploy in shared heterogenous environments such as the Internet. On the Internet, mediastreaming systems must be capable of trading off resource requirements against the quality of the media streams they deliver, in order to match wide-ranging dynamic variations in bandwidth between servers and clients. Since quality requirements tend to be user- and task-specific, mechanisms for capturing quality of service requirements and mapping them to appropriate resource-level adaptation policies are required. In this paper, we describe a general approach for automatically mapping user-level quality of service specifications onto resource …

Bs News

Building Services Engineering

No abstract provided.

Evaluation Of Bond Using Frp Rods With Axisymmetric Deformations, Mesfer M. Al-Zahrani, Salah U. Al-Dulaijan, Antonio Nanni, Charles E. Bakis, Thomas E. Boothby

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents experimental results obtained with the direct pull-out test using machined and wrapped glass/vinyl ester, carbon/vinyl ester, and carbon/epoxy FRP rods with axisymmetric lugs. The typical results are given as nominal shear stress vs. free- and loaded-end slip. Experimental results obtained from strain probes used during the pull-out test are presented as shear stress vs. strain. Machined glass/vinyl ester FRP rods with embedded lengths including five and 10 lugs, and different lug widths and heights were studied. The failure mode consisted of the shearing off of the lugs without concrete damage. Four concrete mixtures with strengths ranging from …

Cellular/Dendritic Array Tip Morphology During Directional Solidification Of Pb-5.8 Wt Pct Sb Alloy, L. Yu, G. L. Ding, J. Reye, S. N. Ojha, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

Cellular/dendritic array tip morphology has been examined in directionally solidified and quenched Pb-5.8 wt pet Sb alloy by a serial sectioning and three-dimensional image reconstruction technique. There is a large scatter in the tip radius, the nearest neighbor spacing, and the mushy zone length, even among the immediately neighboring cells and dendrites. This scatter may be caused by the natural convection (in the mushy zone and in the bulk melt at the array tip), which also produces macrosegregation along the length of the directionally solidified samples. Even in the presence of convection, however, the tip radii are observed to be …

Galnnas Resonant-Cavity-Enhanced Photodetector Operating At 1.3 Μm, J. B. Heroux, Xiaodong Yang, W. I. Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We demonstrate a GaAs-based p-i-n resonant-cavity-enhanced (RCE) GalnNAs photodetector operating near 1.3 µm. The device design was optimized using a transfer matrix method and experimental absorption spectra obtained from p-i-n structures grown without a resonant cavity. The RCE photodetector was fabricated in a single growth step by using GaAs/AlAs distributed Bragg reflectors for the top and bottom mirrors. A 72% quantum efficiency was obtained with a full width at half maximum of 11 nm.

Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu

Electro-Optics and Photonics Faculty Publications

An optoelectronic switching network with 2-D optical fiber bundle arrays I/O access device is presented in this paper. An optoelectronic recirculating Banyan network based on CMOS/SEED smart pixel device is used in this configuration. Thirty-two X two single-mode fiber bundle array and 32 X 2 multi- mode fiber bundle array are fabricated respectively based on the features of high density, high precision and array permutation of the CMOS/SEED optoelectronic integrated devices. The measuring results show that the center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125 micrometer, and the spacing between …

An Analysis Of Wastewater Generated During Water Jetting Tests On The I-65 John F. Kennedy Bridge At Louisville, Bobby W. Meade, Theodore Hopwood Ii, Sudhir Palle

Kentucky Transportation Center Research Report

High pressure water jetting was evaluated as a surface preparation tool for bridge maintenance painting. The tests were conducted on the John F. Kennedy Bridge, which has lead containing existing paint system. The primary concerns were the surface preparation and the lead levels of the wastewater. Test areas were washed at 10,000 psi, 15,000 psi, and 20,000 psi and wastewater was collected for analysis. Lead tests were conducted on unfiltered wastewater and wastewater filtered through a variety of filter fabrics. High-pressure water jetting produces and excellent surface for painting but, on bridges with existing lead paint, the wastewater lead levels …

Professional Contracting Certification: An Examination And Model Development, Robert D. Lorton, Daniel I. Dunn

Theses and Dissertations

This study compared the elements of existing contracting certification programs to an ideal contracting certification model developed by experts. The expert panel responded to an open-ended electronic interview to convey their ideas regarding the individual elements for the model. Input received from the initial interviews was used to develop a survey for the panel members. The surveys were completed and results were recorded and conveyed back to the panel members. This process was repeated until a majority was reached on each individual element of the model, resulting in the ideal certification model. The final model contained elements of both the …

The Effect Of Action Workouts On Aircraft Mission Capability Measurements, Michael P. Allison

Theses and Dissertations

Previous studies concerning quality improvement and the Action Workout Process attempted to define and describe the difficult concept of quality. A logical next step is to study to what extent implementation of a quality improvement program, such as ACC's Action Workout Process, positively or negatively affects performance factors within an Air Force organization. This study focused on exploring the fundamental question of whether there was, as a result of the Action Workout, a noticeable, statistically verifiable, positive or negative change in the mission capability of aircraft assigned to the units carrying out this quality improvement initiative. Research questions were developed …

The Challenge Of Maintaining Or Replacing An Aging Airlift Fleet: A Cost/Capability Analysis For The Brazilian Air Force Mobility System, Julio C. Messias

Theses and Dissertations

Despite the high Operational and Support costs incurred, the Brazilian Air Force's (BAF) declining budget has led to the establishment of conservative policies that favor short run solutions for a critical BAF airlift problem of operating an aging fleet. As a result of this policy, service life extensions of older airlift aircraft are the preferred solution. Using an equal airlift capacity approach to examine the Brazilian Air Force mobility system, this research performs a cost comparison analysis between two aircraft currently in operation at Brazilian's airlift command: C-130 Hercules and C-95 Bandeirante. To accomplish the cost analysis, this research develops …

A Methodology For The Analysis And Prediction Of Air Force Enlisted Aircraft Maintenance Personnel Retention Rates Using Economic Statistics, Peter D. Lommen

Theses and Dissertations

The purpose of this study is to investigate the effects of certain national economic indicators on enlisted aircraft maintenance personnel retention rates. To fulfill this purpose, this study builds a linear regression equation that can predict the retention rate using the civilian unemployment rate and the index of 11 leading economic indicators as the independent variables. Journal literature and economic texts were reviewed to identify the indicators as good predictors for changes in employee turnover. The method of linear regression was used to build the model needed to predict the changes in the retention rate. The equation developed with this …

Space-Available Transportation: An Analysis Of The Cost Of Providing 'Free' Travel, Frank J. Long

Theses and Dissertations

The purpose of this study is to estimate the costs borne by the government for providing space-available travel to eligible uniformed services personnel and their dependents. As the primary provider of the space-available privilege, it is important that the Air Force have an estimate of the burden that the administration of that privilege places on the budget. In January 1993, the Air Force discontinued its 15-year-old practice of charging a fee for space-available travel aboard AMC-owned or controlled aircraft. The fee had been set at $10 in 1978 and was collected to recover a portion of the costs associated with …

The Privatization Of The Aerospace Guidance And Metrology Center At Newark Air Force Base, Richard H. Fillman Jr.

Theses and Dissertations

The Aerospace Guidance and Metrology Center (AGMC) at Newark AFB was privatized in place as a result of the 1993 BRAC process. This was a first of a kind for the DoD repair depot system. The justification was too much excess depot capacity and by closing Newark the Air Force would rid itself of this excess capacity and obtain savings by privatizing the repair workload. This thesis concentrates on whether excess capacity at AGMC was as large as it was identified and if cost saving had materialized at the depot since the privatization. To determine how well the depot repairs …

Reparable Inventory Reduction: Impacts On Air Force Fighter Aicraft Mission Capability, Gregory E. Hutson

Theses and Dissertations

During the 1990's the Air Force experienced severe declines in serviceable inventory levels and a rise in their TNMCS rates. Air Force predictions of TNMCS hours during this time period did not account for the upward trend in TNMCS rates. The Air Force uses a regression equation, consisting of possessed hours, flying hours, and sorties, to predict TNMCS hours. This research, through simple linear regression, found a significant relationship between serviceable inventory levels and TNMCS rates for 8 of the 10 aircraft studied. Using this relationship, serviceable inventory levels were then added to the Air Force equations and new multiple …

An Ex Post Facto Analysis Of E-3 Maintenance Indicators In The 552d Air Control Wing Since Reorganization Under An Aircraft Generation Squadron Concept, Larry J. Stetz

Theses and Dissertations

Organizational restructuring sometimes occurs in the aircraft maintenance field, yet seldom are in-depth analyses performed after the fact to see if productivity improved. In December 1995, the 552D Air Control Wing restructured its flight line maintenance into an aircraft generation squadron concept. This study looked at before and after maintenance indicators to see if productivity improved. Maintenance data was collected from December 1993 to December 1997. Nineteen maintenance indicators were identified, and the key indicators were analyzed using means comparison and regression analysis to determine if efficiency and effectiveness had increased. The variables Mission Capable rate and Man-hours per Flying …

Comparison Of The Effects Of Eight-Hour And Twelve-Hour Shifts On Air Force Aircraft Maintenance Production Levels, David P. Collette

Theses and Dissertations

his is a follow-on study that examined the effects of converting a large aircraft maintenance squadron from 8-hour shifts to 12-hour shifts. The squadron studied converted its 24-hour maintenance work force from three 8-hour work shifts to two 12-hour work shifts. Data was collected from four different time periods. Three time periods were used for a primary analysis and all four time periods were used for trend analysis. To determine if the 12-hour work shift was effective, workforce productivity was measured during the different work shift periods. Results showed an increase in two productivity measurements, no-change in two productivity measurements, …

An Exploratory Analysis Of The Responsiveness Capability Of The Air Expeditionary Wing (Aew) Concept, Robert L. Charlesworth

Theses and Dissertations

Seven AEF deployments have been accomplished in the Southwest Asia area of responsibility; none have met the Air Force's stringent 72 hour criterion. This exploratory study quantifies the responsiveness capability of the AEW concept. Based on a Monte Carlo simulation methodology this study concludes that the on call AEW at Mountain Home AFB does not have the capability to meet the 72 hour criterion. Additionally, this study examined the effect of three departures from the baseline model on responsiveness capability. These departures included: increasing airlift throughput capacity, incorporating limited airlift failure, and employing an air refueling scenario. The simulation models …

Cost-Benefit Analysis Of Leasing Versus Buying Air Force General Purpose Vehicles In The Continental United States, Robert J. Neal Jr.

Theses and Dissertations

Given the increasingly aging vehicle fleet and declining vehicle budget, this research performed a cost-benefit analysis of leasing versus buying various Air Force general purpose vehicles for the entire continental United States (CONUS). In contrast to previous analyses, which have examined the leasing versus buying issue on a base-by-base basis, this analysis studies the issue from an Air Force-wide perspective using a cost-buying model. Costs and benefits are calculated for three purchasing options (Air Force ownership, GSA leasing, and commercial leasing) to determine and recommend the best alternative for the Air Force. Finally, a sensitivity analysis is to test the …

Analysis Of Traffic Accident Data In Kentucky (1994 - 1998), Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

This report includes an analysis of traffic accident data in Kentucky for the years of 1994 through 1998. A primary objective of this study was to determine average accident statistics for Kentucky highways. Average and critical numbers and rates of accidents were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky's procedure to identify locations that have abnormal rates or numbers of accidents.

The other primary objective of this study was to provide data which can be used in the preparation of the problem identification portion of Kentucky's Annual Highway Safety …

Correlation Of Rock Quality Designation And Rock Scour Around Bridge Piers And Abutments Founded On Rock, Tommy C. Hopkins, Tony L. Beckham

Kentucky Transportation Center Research Report

Local scour around the base of a bridge pier or abutment occurs as the result of flow acceleration around the obstruction, formation of a vertical pressure gradient along the upstream end, and generation of vortices at the base of the structure. The flow patterns around piers and abutments are complex in detail, and the complexity increases as a scour hole forms in the bed around the structures. The potential for local scour at a bridge pier or abutment needs to be estimated so that foundations can be designed to resist failure during large floods. While procedures have been suggested for …