Oxidizing seal for a turbine tip gas path

The sealing of the gas path in a gas turbine engine at the blade tips is improved by maintaining a minimum clearance between the rotor blade tips and the gas path seal. This is accomplished by taking advantage of an increase in volume during controlled oxidation of certain intermetallic compounds which have high melting points. The increase in volume closes the clearance subsequent to a rub between the blades and the seal. Thus, these compounds re-form the tip seal surface to assure continued engine efficiency

The effects of zinc sulfate on ethyl glucuronide immunoassay urine testing

Published research in the Journal of Analytical Toxicology and the American Society for Clinical Pathology has confirmed that the presence of Zinc Sulfate in adulterated urine samples can influence the testing results using EMIT and ELISA immunoassay testing when testing for Cannabinoids (THC), Cocaine (Benzoylecgonine), Methamphetamines, Opiates (Morphine, Methadone, and Propoxyphene), Phencyclidine (PCP), and Ethanol (Alcohol Dehydrogenase). This research included adding Zinc Sulfate directly to urine samples. In 2006, the Substance Abuse and Mental Health Service Administration (SAMHSA) released an advisory that the use of Ethyl glucuronide (EtG) as a new biomarker as an indicator for the past-use of alcohol was promising and warranted more research. Ethyl glucuronide is a direct metabolite of the biotransformation of ethanol in the human body. This compound is excreted in urine and can be used as a specific biomarker for the ingestion of alcohol. Because EtG is only produced when ethanol is metabolized, there are no false positives due to fermentation and a much longer detection window exists for its detection. Scientific literature states that EtG can be present in urine long after ethanol has been eliminated. Testing for EtG is commonly referred to as the “80 hour test” for the ability of EtG to be measured up to 80 hours after consuming alcohol. It was hypothesized that if the presence of Zinc Sulfate added to urine falsely reduced urine alcohol level when measuring for Alcohol Dehydrogenase enzyme, will the presence of Zinc Sulfate added to SurineTM falsely reduce the urine alcohol level when measuring for EtG? Since it is very likely that EtG would still be present in the body after ethanol has been eliminated, samples contained either no ethanol or 5% (5g/dL) of ethanol. Samples were spiked at 10mg/mL, 15mg/mL or contained 0mg/mL of Zinc Sulfate. Additionally, duration testing was conducted to see if there was any observed differences between testing the samples fresh and then after a one week duration in a refrigerator and brought to room temperature prior to testing. Two different immunoassay EtG tests were used to perform the analysis. It was concluded that Zinc Sulfate directly added to the sample affected one of the immunoassay test regardless of whether EtG or ethanol were present, by fading the Test and Control regions. Additionally, it is concluded that SurineTM samples containing Zinc Sulfate could easily be distinguished from samples free of Zinc Sulfate because of the presence of a white cloudy precipitate

Independent Component Analysis for Improved Defect Detection in Guided Wave Monitoring

Guided wave sensors are widely used in a number of industries and have found particular application in the oil and gas industry for the inspection of pipework. Traditionally this type of sensor was used for one-off inspections, but in recent years there has been a move towards permanent installation of the sensor. This has enabled highly repeatable readings of the same section of pipe, potentially allowing improvements in defect detection and classification. This paper proposes a novel approach using independent component analysis to decompose repeat guided wave signals into constituent independent components. This separates the defect from coherent noise caused by changing environmental conditions, improving detectability. This paper demonstrates independent component analysis applied to guided wave signals from a range of industrial inspection scenarios. The analysis is performed on test data from pipe loops that have been subject to multiple temperature cycles both in undamaged and damaged states. In addition to processing data from experimental damaged conditions, simulated damage signals have been added to “undamaged” experimental data, so enabling multiple different damage scenarios to be investigated. The algorithm has also been used to process guided wave signals from finite element simulations of a pipe with distributed shallow general corrosion, within which there is a patch of severe corrosion. In all these scenarios, the independent component analysis algorithm was able to extract the defect signal, rejecting coherent noise

The Interface of Technology in Culinary Arts Education

Introduction: A culinary educator must make many decisions that affect the day-to-day activities in both the classroom and the lab. One of the more important decisions is how to select the most appropriate technology to implement for use in teaching and administrative activities. The research presented here is intended to help the educator identify specific needs, decide where the use of technology is desirable, and offer information designed to help the educator make an informed decision about using technology as a teaching tool. Purpose Statement: The purpose of this paper is to inform the culinary educator about the technology available for use in both the classroom and the lab setting. There is an ever-increasing pool of technology, making it more important than ever that the educator choose the appropriate lab/kitchen equipment and software programs for use in a specific culinary program. Making an informed decision ensures maximum usefulness of the technology in the setting

A Guide (and Advice) for Economists on the U. S. Junior Academic Job Market

This document describes the U. S. academic job market for new Ph.D. economists and offers advice on conducting an academic job search. It reports findings from published papers, describes practical details, and provides links to internet resources. Topics addressed include: preparing to go on the market, applying for academic jobs, interviewing, campus visits, offers and negotiating, diversity, and dual job searches. This paper is no longer available on this working paper archive. The paper is available as part of the September 2002 Job Openings for Economists and can be downloaded at: http://www.eco.utexas.edu/joe/junior academic economics job market guide advice

Contingent Valuation Analysis of Willingness to Pay To Reduce Childhood Obesity

Several recent surveys have asked Americans whether they support policies to reduce childhood obesity. There is reason for skepticism of such surveys because people are not confronted with the tax costs of such policies when they are asked whether they support them. This paper uses contingent valuation (CV), a method frequently used to estimate people’s willingness to pay (WTP) for goods or services not transacted in markets, applied to unique survey data from New York State to estimate the willingness to pay to reduce childhood obesity. The willingness to pay data correlate in predictable ways with respondent characteristics. The mean WTP for a 50% reduction in childhood obesity is $46.41 (95$33.45, $59.15), which implies a total WTP by New York State residents of$690.6 million (95% CI: $497.7,$880.15), which is less than that implied by previous surveys that did not use CV methods but greater than current spending on policies to reduce childhood obesity and greater than the estimated savings in external costs. The findings provide policymakers with useful information about taxpayers' support for, and preferred budget for, anti-obesity policies.

Tape casting as an approach to an all-ceramic turbine shroud seal

Gas path seals have a one-dimensional variation in material requirement. Tape casting is a method which allows the fabrication of thin ceramic sheets, which may be laminated to accommodate these requirements. Using tape casting, thin sheets of zirconia (0.25 mm) were fabricated. These castings were successfully laminated and fired without bloating or delamination, demonstrating the feasibility of this approach