Separation of Lift-Generated Vortex Wakes Into Two Diverging Parts

As part of an ongoing study of the spreading rate of lift-generated vortex wakes, the present investigation considers possible reasons as to why segments of lift-generated wakes sometimes depart from the main part of the wake to move rapidly in either an upward or downward direction. It is assumed that deficiencies or enhancements of the lift carry over across the fuselage-shrouded wing are the driving mechanism for departures of wake-segments. The computations presented first indicate that upwardly departing wake segments that were observed and photographed could have been produced by a deficiency in lift carryover across the fuselage-shrouded part of the wing. Computations made of idealized vortex wakes indicate that upward departure of a wake segment requires a centerline reduction in the span loading of 70% or more, whether the engines are at idle or robust thrust. Similarly, it was found that downward departure of wake segments is produced when the lift over the center part of the wing is enhanced. However, it was also found that downward departures do not occur without the presence of robust engine-exhaust streams (i.e., engines must NOT be at idle). In those cases, downward departures of a wake segment occurs when the centerline value of the loading is enhanced by any amount between about 10% to 100%. Observations of condensation trails indicate that downward departure of wake segments is rare. Upward departures of wake segments appears to be more common but still rare. A study to determine the part of the aircraft that causes wake departures has not been carried out. However, even though departures of wake segments rarely occur, some aircraft do regularly shed these wake structures. If aircraft safety is to be assured to a high degree of reliability, and a solution for eliminating them is not implemented, existing guidelines for the avoidance of vortex wakes [1,3] may need to be broadened to include possible increases in wake sizes caused by vertical departures of wake segments. Further study may indicate that it is not possible to modify existing aircraft enough to prevent wake departures. Wake-avoidance guidelines must then be adjusted to provide the desired degree of safety. It appears that steps to avoid upwardly moving wake segments have already been incorporated into the avoidance procedures used for aircraft on approach to runways at the Frankfurt Airport [6,7]. The uncertainty in the prospects for compromises in flight safety caused by rapidly upwardly or downwardly moving wake segments suggest that it be specified that aircraft do not fly above or below each other during operations in the airport vicinity where aircraft are likely to be closely spaced [20]

Chronicles of Oklahoma

Article discusses the work of the author, an American Airlines pilot on the Butterfield Overland Mail Route. Vernon H. Brown describes the history of the route and its founder, its layout in Oklahoma, and plans for the Oklahoma Semi-Centennial Celebration that included a marking of the route

Use of a Pulsed Photomultiplier to Measure the Light Intensity Versus Time for a Spark Discharge Between Aluminum Electrodes

Higher Educatio

Socio-demographic inequalities in stage of cancer diagnosis: Evidence from patients with female breast,lung, colon, rectal, prostate, renal, bladder, melanoma, ovarian and endometrial cancer

This is the final published version. Available from Oxford University Press via the DOI in this record.Background: Understanding socio-demographic inequalities in stage at diagnosis can inform priorities for cancer control. Patients and methods: We analysed data on the stage at diagnosis of East of England patients diagnosed with any of 10 common cancers, 2006-2010. Stage information was available on 88 657 of 98 942 tumours (89.6%). Results: Substantial socio-demographic inequalities in advanced stage at diagnosis (i.e. stage III/IV) existed for seven cancers, but their magnitude and direction varied greatly by cancer: advanced stage at diagnosis was more likely for older patients with melanoma but less likely for older patients with lung cancer [odds ratios for 75-79 versus 65-69 1.60 (1.38-1.86) and 0.83 (0.77-0.89), respectively]. Deprived patients were more likely to be diagnosed in advanced stage for melanoma, prostate, endometrial and (female) breast cancer: odds ratios (most versus least deprived quintile) from 2.24 (1.66-3.03) for melanoma to 1.31 (1.15-1.49) for breast cancer. In England, elimination of sociodemographic inequalities in stage at diagnosis could decrease the number of patients with cancer diagnosed in advanced stage by 5600 annually. Conclusions: There are substantial socio-demographic inequalities in stage at diagnosis for most cancers. Earlier detection interventions and policies can be targeted on patients at higher risk of advanced stage diagnosis. ©The Author 2012.National Institute for Health Research (NIHR

Spectroscopic Measurements Of Temperature And Plasma Impurity Concentration During Magnetic Reconnection At The Swarthmore Spheromak Experiment

Electron temperature measurements during counterhelicity spheromak merging studies at the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] are presented. VUV monochromator measurements of impurity emission lines are compared with model spectra produced by the non-LTE excitation kinematics code PRISMSPECT [J. J. MacFarlane et al., in Proceedings of the Third Conference on Inertial Fusion Science and Applications (2004)] to yield the electron temperature in the plasma with 1 mu s time resolution. Average T(e) is seen to increase from 12 to 19 eV during spheromak merging. Average C III ion temperature, measured with a new ion Doppler spectrometer (IDS) [C. D. Cothran et al., Rev. Sci. Instrum. 77, 063504 (2006)], likewise rises during spheromak merging, peaking at similar to 22 eV, but a similar increase in T(i) is seen during single spheromak discharges with no merging. The VUV emission line measurements are also used to constrain the concentrations of various impurities in the SSX plasma, which are dominated by carbon, but include some oxygen and nitrogen. A burst of soft x-ray emission is seen during reconnection with a new four-channel detector (SXR). There is evidence for spectral changes in the soft x-ray emission as reconnection progresses, although our single-temperature equilibrium spectral models are not able to provide adequate fits to all the SXR data. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3099603

Community-identified strategies to increase physical activity during elementary school recess on an American Indian reservation: A pilot study

AbstractThe aim of this study was to determine the effect of an 8-week recess intervention on physical activity levels in children attending elementary school on an American Indian reservation during fall 2013.Physical activity was measured with direct observation in three zones on the playground. Lines were painted on existing pavement in zone 1. Zone 2 had permanent playground equipment and was unchanged. Zone 3 contained fields where bi-weekly facilitators led activities and provided equipment. Pre- to post-changes during recess in sedentary, moderate physical activity, moderate-to-vigorous, and vigorous physical activities were compared within zones.Females physical activity increased in Zone 1 (moderate: 100% increase; moderate-to-vigorous: 83%; vigorous: 74%, p<0.01 for all) and Zone 3 (moderate: 54% increase, p<0.01; moderate-to-vigorous: 48%, p<0.01; vigorous: 40%, p<0.05). Male sedentary activity decreased in Zone 2 (161%, p<0.01). Physical activity changes in Zone 3 were not dependent upon the presence of a facilitator.Simple and low-cost strategies were effective at increasing recess physical activity in females. The findings also suggest that providing children games that are led by a facilitator is not necessary to increase physical activity as long as proper equipment is provided