F111 Engine Compressor Disc Cracking - A Case Study Of The Use Of Fractography To Determine Fleet Safety

In August, 1999, two separate incidences of "unusual" cracking were found by routine liquid penetrant non destructive inspection in F111 engine (TF30) titanium alloy compressor discs in quick succession. Cracking occurred in the tie rod holes of the discs which had never previously been reported. Due to the potentially serious consequences of in-flight failure of engine compressor discs, the fleet was grounded until the nature and significance of the cracking was determined. The cracks were forced fractured and subjected to fractographic analysis, the information from which providing the "key" in determining the cause and significance of the cracking and the likelihood of fleetwide implications. The analysis was interesting due to the unusual aspect ratio of one of the cracks, and the presence of cadmium which it was thought may have been significant in the incidence of cracking. Fractography and metallography was also used to aid in the development of a suitably sensitive eddy current non destructive inspection technique for specific inspection of tie rod holes in compressor discs during future overhauls. This paper will describe the circumstances of the incidences of cracking, the safety concerns, the details of fractographic analysis, and the development of the eddy current procedure

Vol. 2 Ch. 0 Contents and front matter

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Redefining Race in Saint Francis College v. Al-Khazraji and Shaare Tefila Congregation v. Cobb: Using Dictionaries Instead of the Thirteenth Amendment

In 1987 the Supreme Court unanimously extended the protections of 42 U.S.C. sections 19811 and 19822 to ethnic groups, citing Runyon v. McCrary. Runyon reinterpreted the legislative history of section 1981 to create a cause of action for blacks against both public and private discrimination in the making and enforcement of contracts. One year later a sharply divided Supreme Court ordered the parties in Patterson v. McLean Credit Union, a case in which the Court already had heard argument, to brief the Court anew and make arguments on an issue that none of the parties had raised--whether to overrule Runyonv. McCrary.\u27The Supreme Court\u27s request reminded the legal community that the constitutional authority for Runyon is and always has been in dispute. Yet Justice White, who with Justice Rehnquist wrote the vehement and widely cited dissent to Runyon, authored the unanimous opinions for the Court in Saint Francis College v. Al-Khazraji and Shaare Tefila Congregation v. Cobb, which permit ethnic groups to employ sections 1981 and 1982 in order to reach private acts of discrimination. The justices of the Supreme Court accomplished this expansion of Runyon without examining precedent or establishing a constitutional foundation. Rather, the Court defined the term race to include ethnic minorities for the purposes of sections 1981 and 1982. The American media overwhelmingly endorsed the Supreme Court\u27s decision, believing it to be a significant expansion of civil rights--a reflection of the modern belief that all ethnic minorities equally deserve freedom from discrimination. The New York Times declared that the decisions created an opportunity for many Americans to fight ethnic discrimination. If the decisions, however, are as significant an expansion of civil rights as the press perceived them to be, the Supreme Court should have based its analysis on the United States Constitution

Vol. 2 Ch. a Index

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Male earnings inequality, women’s employment and family income inequality in Australia, 1982 – 2007

This paper uses cross-sectional data to examine the relationship between the growth in earnings inequality among men, changes in women’s earnings and changes in family income inequality in Australia between 1982 and 2007-08. Male earnings inequality increased substantially across this period, as did women’s participation in paid work. Our analysis shows that both impacted on family income inequality, which rose by a relatively small amount. We also show that the impact of changes in women’s employment and earnings on family income inequality changed over the study period. During the years associated with the Hawke-Keating Labor government (1982 to 1995-96), growth in women’s earnings pushed family income inequality higher. However, during the tenure of the Howard government (1995-96 to 2007-08) the pattern reversed, with continued growth in women’s earnings contributing a moderating influence on family income inequality. These findings deliver new evidence on the importance of trends in family formation and the correlation of husbands’ and wives’ earnings to the evolution of family income inequality. They also show the potential effects of a range of policy initiatives on this evolution

Male Earnings Inequality, Women’s Employment and Family Income Inequality in Australia, 1982 - 2007

This preliminary paper uses cross-sectional data to examine the relationship between the growth inearnings inequality among men and women, and changes in family income inequality in Australia between 1982 and 2007-08. Although male earnings inequality increased substantially across this period, change in family income inequality was less significant. Our analysis shows that women?s earnings played a role in moderating the effects of rising male earnings inequality on the inequality of family income. This effect increased between 1982 and 2007-08, reflecting a pattern of change in women?s employment across households with low and high male earnings. The effects of this pattern of change are currently under-researched in the Australian context. Results presented in this paper have significance for understandings not only of the relationship between women?s earnings and family income inequality, but also the relationship between the hours that women work and family income inequality

Signal quality measures for unsupervised blood pressure measurement

Accurate systolic and diastolic pressure estimation, using automated blood pressure measurement, is difficult to achieve when the transduced signals are contaminated with noise or interference, such as movement artifact. This study presents an algorithm for automated signal quality assessment in blood pressure measurement by determining the feasibility of accurately detecting systolic and diastolic pressures when corrupted with various levels of movement artifact. The performance of the proposed algorithm is compared to a manually annotated reference scoring (RS). Based on visual representations and audible playback of Korotkoff sounds, the creation of the RS involved two experts identifying sections of the recorded sounds and annotating sections of noise contamination. The experts determined the systolic and diastolic pressure in 100 recorded Korotkoff sound recordings, using a simultaneous electrocardiograph as a reference signal. The recorded Korotkoff sounds were acquired from 25 healthy subjects (16 men and 9 women) with a total of four measurements per subject. Two of these measurements contained purposely induced noise artifact caused by subject movement. Morphological changes in the cuff pressure signal and the width of the Korotkoff pulse were extracted features which were believed to be correlated with the noise presence in the recorded Korotkoff sounds. Verification of reliable Korotkoff pulses was also performed using extracted features from the oscillometric waveform as recorded from the inflatable cuff. The time between an identified noise section and a verified Korotkoff pulse was the key feature used to determine the validity of possible systolic and diastolic pressures in noise contaminated Korotkoff sounds. The performance of the algorithm was assessed based on the ability to: verify if a signal was contaminated with any noise; the accuracy, sensitivity and specificity of this noise classification, and the systolic and diastolic pressure differences between the result obtained from the algorithm and the RS. 90% of the actual noise contaminated signals were correctly identified, and a sample-wise accuracy, sensitivity and specificity of 97.0%, 80.61% and 98.16%, respectively, were obtained from 100 pooled signals. The mean systolic and diastolic differences were 0.37 ± 3.31 and 3.10 ± 5.46 mmHg, respectively, when the artifact detection algorithm was utilized, with the algorithm correctly determined if the signal was clean enough to attempt an estimation of systolic or diastolic pressures in 93% of blood pressure measurements

Covid 19: Impacts on teaching, learning and progression for A Levels in Mathematics.

We report on ways that teaching and learning for mathematics A Levels, studied pre-university in England (by students aged 16-18), was disrupted by Covid19 in Summer 2020. Findings are contextualised within teacher and student accounts of the aspirational and time-pressured nature of these reformed qualifications. We explore the nature of engagement with mathematics achieved by year 12 and 13 students during lockdown, and the preparedness of 2019-20 year 11 and 13 students for progression into A Level/Higher Education respectively. Our findings derive from the third year of a four-year study (2017/18 to 2020/21) exploring enactment and impact of reformed mathematics A Levels, and efficacy of associated Pearson resources and assessments. Research tools were adapted to focus on impacts of Covid19. We present a snapshot (March to July 2020), of teachers and students looking to the future in a time of uncertainty and rapid change