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The reliability of wear/failure data of brake assemblies of a commercial aeroplane (Boeing 737) is analysed using the Weibull model. This model can be effectively integrated into an aviation maintenance facility computerized material requirement planning system to forecast the number of brake assemblies needed for a given planning horizon. Copyright © 1999 John Wiley & Sons, Ltd.

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It has become evident that the modeling of the complex dynamics of fluidelastic forces that give rise to vibrations of tube bundles requires a great deal of experimental insight. Accordingly, the prediction of the flow-induced vibration due to unsteady cross-flow can be greatly aided by semi-analytical models, in which some coefficients are determined experimentally. A laboratory test rig with an instrumented test bundle is constructed to measure the fluidelastic coefficients to be used in conjunction with the mathematical model derived in Part I of this paper. The test rig admits two different test bundles, namely, the inline-square and 45deg rotated-square tube arrays. Measurements were conducted to identify the flow-induced dynamic coefficients. The developed scheme was utilized in predicting the onset of flow-induced vibrations in two configurations of tube bundles, and results were examined in the light of Tubular Exchange Manufacturers Association (TEMA) predictions. The comparison demonstrated that TEMA guidelines are more conservative in the two configurations considered.

BACKGROUND: Hypertension is common in patients with atrial fibrillation (AF) and is an important cause of stroke. OBJECTIVES: To determine how effectively hypertension is managed among specialist-treated outpatients with AF. METHODS: Investigators reviewed the charts of patients with a diagnosis of AF cared for by medical specialists to determine the change in blood pressure, patterns of antihypertensive drug use and the role of the specialist in the management of hypertension. RESULTS: Of 209 patients with AF, 118 had a history of hypertension or an office blood pressure greater than 140/90 mmHg. Blood pressure was measured at 73% of all visits. Hypertension was identified as an important problem in 57% of patients and antihypertensive therapy was either initiated or suggested in 77%. One year after the initial specialist visit, systolic blood pressure was significantly lower (140±20 mmHg at one year versus 148±23 mmHg initially; P=0.015); however, there was no change in diastolic blood pressure (80±12 mmHg at one year versus 81±16 mmHg initially; P=0.602) and only 50% of patients had a blood pressure less than 140/90 mmHg. In contrast, the percentage of patients receiving warfarin increased from 46% to 78% (P=0.0001). CONCLUSIONS: In patients treated by specialists for AF, systolic blood pressure is significantly reduced during follow-up; however, 50% of patients continue to have suboptimal blood pressure control. In many patients, hypertension is not identified as an important comorbid illness and antihypertensive therapy is neither recommended nor initiated by the specialist. Greater specialist involvement in the identification and treatment of hypertension in patients with AF could lead to an important, additional reduction in stroke.