Design considerations for attaining 200-knot test velocities at the aircraft landing loads and traction facility

Design studies are presented which consider the important parameters in providing 200 knot test velocities at the landing loads and traction facility. Two major components of this facility, the hydraulic jet catapult and the test carriage structure, are considered. Suitable factors are determined to correlate analytical data for characteristics of the hydraulic jet catapult with data measured from the existing catapult system. The resulting equations are used to calculate test velocities for a range of jet nozzle diameters and carriage masses with both the current 122 m and an increased 183 m catapult stroke. Using the catapult characteristics, a target design point is selected and a carriage structure is sized to meet the target point strength requirements

Practices, Core Practices and the Work of the Holy Spirit

The recent interest in practices has created a multi-faceted discussion in theological circles that brings together insights from many disciplines such as ethics, philosophy, and cultural anthropology. However, there has been little extended analysis about how the many claims made about practices are related to quite similar claims traditionally made about the work of the Holy Spirit. In this paper, four distinctions are highlighted that can help us better conceptualize how the Holy Spirit might be related to different kinds of practices

Comparative Tuberculosis

Efforts directed against bovine tuberculosis have resulted in a reduction of specimens submitted for examination for tuberculosis. The infrequency of such specimens has made it harder to demonstrate to students fresh specimens of tuberculosis. Fresh specimens are always more interesting than preserved specimens, and it is desirable to have as many fresh specimens as possible

Some Chemical Engineering Aspects of Loss Heat from Surfaces.

Abstract Not Provided

The effect of chine tires on nose gear water-spray characteristics of a twin engine airplane

An experimental investigation was performed to evaluate the effectiveness of nose gear chine tires in eliminating or minimizing the engine spray ingestion problem encountered on several occasions by the Merlin 4, a twin-engine propjet airplane. A study of the photographic and television coverage indicated that under similar test conditions the spray from the chine tires presented less of a potential engine spray ingestion problem than the conventional tires. Neither tire configuration appeared to pose any ingestion problem at aircraft speeds in excess of the hydroplaning speed for each tire, however, significant differences were noted in the spray patterns of the two sets of tires at sub-hydroplaning speeds. At sub-hydroplaning speeds, the conventional tires produced substantial spray above the wing which approached the general area of the engine air inlet at lower test speeds. The chine tires produced two distinct spray plumes at sub-hydroplaning speeds: one low-level plume which presented no apparent threat of ingestion, and one which at most test speeds was observed to be below the wing leading edge and thus displaced from the intakes on the engine nacelle

Static and yawed-rolling mechanical properties of two type 7 aircraft tires

Selected mechanical properties of 18 x 5.5 and 49 x 17 size, type 7 aircraft tires were evaluated. The tires were subjected to pure vertical loads and to combined vertical and lateral loads under both static and rolling conditions. Parameters for the static tests consisted of tire load in the vertical and lateral directions, and parameters for the rolling tests included tire vertical load, yaw angle, and ground speed. Effects of each of these parameters on the measured tire characteristics are discussed and, where possible, compared with previous work. Results indicate that dynamic tire properties under investigation were generally insensitive to speed variations and therefore tend to support the conclusion that many tire dynamic characteristics can be obtained from static and low speed rolling tests. Furthermore, many of the tire mechanical properties are in good agreement with empirical predictions based on earlier research

Sky Variability in the y Band at the LSST Site

We have measured spatial and temporal variability in the y band sky brightness over the course of four nights above Cerro Tololo near Cerro Pachon, Chile, the planned site for the Large Synoptic Survey Telescope (LSST). Our wide-angle camera lens provided a 41 deg field of view and a 145 arcsec pixel scale. We minimized potential system throughput differences by deploying a deep depletion CCD and a filter that matches the proposed LSST y_3 band (970 nm-1030 nm). Images of the sky exhibited coherent wave structure, attributable to atmospheric gravity waves at 90 km altitude, creating 3%-4% rms spatial sky flux variability on scales of about 2 degrees and larger. Over the course of a full night the y_3 band additionally showed highly coherent temporal variability of up to a factor of 2 in flux. We estimate the mean absolute sky level to be approximately y_3 = 17.8 mag (Vega), or y_3 = 18.3 mag (AB). While our observations were made through a y_3 filter, the relative sky brightness variability should hold for all proposed y bands, whereas the absolute levels should more strongly depend on spectral response. The spatial variability presents a challenge to wide-field cameras that require illumination correction strategies that make use of stacked sky flats. The temporal variability may warrant an adaptive y band imaging strategy for LSST, to take advantage of times when the sky is darkest.Comment: 8 pages, 5 figures, accepted to PASP. Minor changes from referee report and editor's revisions

Choosing treatment for localised prostate cancer: A patient-conducted-interview study

Objectives: Treatment choice can be particularly difficult in localised prostate cancer because of the uncertainty involved. Indeed, some men prefer maintaining their masculine identity and quality of life to potentially securing longer-term survival through surgery or radiotherapy. UK health services are now obliged to leave the choice of treatment to the patient and the aim of this study is to improve understanding of patients’ experiences of choosing treatment. Methods: A one-day participative workshop where men of six months post-diagnosis design and conduct audio and video interviews on each other about their experiences of choosing treatment. Results: The findings show that treatment choice is a complex process combining emotional and rational elements. Information gathering and delegation to professional expertise were two key themes that emerged. Conclusions: The findings emphasise that treatment choice for localised prostate cancer is little like the traditional notions of consumerism from which it is derived. Importantly, the results illustrate, from a patient perspective, how health professionals can engage in their roles as information providers and as experts