Helicopter main-rotor noise: Determination of source contributions using scaled model data

Acoustic data from a test of a 40 percent model MBB BO-105 helicopter main rotor are scaled to equivalent full-scale flyover cases. The test was conducted in the anechoic open test section of the German-Dutch Windtunnel (DNW). The measured data are in the form of acoustic pressure time histories and spectra from two out-of-flow microphones underneath and foward of the model. These are scaled to correspond to measurements made at locations 150 m below the flight path of a full-scale rotor. For the scaled data, a detailed analysis is given for the identification in the data of the noise contributions from different rotor noise sources. Key results include a component breakdown of the noise contributions, in terms of noise criteria calculations of a weighted sound pressure level (dBA) and perceived noise level (PNL), as functions of rotor advance ratio and descent angle. It is shown for the scaled rotor that, during descent, impulsive blade-vortex interaction (BVI) noise is the dominant contributor to the noise. In level flight and mild climb, broadband blade-turbulent wake interaction (BWI) noise is dominant due to the absence of BVI activity. At high climb angles, BWI is reduced and self-noise from blade boundary-layer turbulence becomes the most prominent

Job Displacement’s Long-run Effect on Access to Employer-provided Health Insurance and Other Fringe Benefits

This paper investigates the effect of job displacement on access to employer-provided fringe benefits. We find that displacement is associated with lost access to all seven employer-provided benefits investigated. These losses increase the cost of displacement by 10% per year

High Resolution HST-STIS Spectra of CI and CO in the Beta Pictoris Circumstellar Disk

High resolution FUV echelle spectra showing absorption features arising from CI and CO gas in the Beta Pictoris circumstellar (CS) disk were obtained on 1997 December 6 and 19 using the Space Telescope Imaging Spectrograph (STIS). An unsaturated spin-forbidden line of CI at 1613.376 A not previously seen in spectra of Beta Pictoris was detected, allowing for an improved determination of the column density of CI at zero velocity relative to the star (the stable component), N = (2-4) x 10^{16} cm^{-2}. Variable components with multiple velocities, which are the signatures of infalling bodies in the Beta Pictoris CS disk, are observed in the CI 1561 A and 1657 A multiplets. Also seen for the first time were two lines arising from the metastable singlet D level of carbon, at 1931 A and 1463 A The results of analysis of the CO A-X (0-0), (1-0), and (2-0) bands are presented, including the bands arising from {13}^CO, with much better precision than has previously been possible, due to the very high resolution provided by the STIS echelle gratings. Only stable CO gas is observed, with a column density N(CO) = (6.3 +/- 0.3) x 10^{14} cm{-2}. An unusual ratio of the column densities of {12}^CO to {13}^CO is found (R = 15 +/- 2). The large difference between the column densities of CI and CO indicates that photodissociation of CO is not the primary source of CI gas in the disk, contrary to previous suggestion.Comment: 13 pages, including 6 figures. LaTex2e (emulateapj5.sty). Accepted for publication in Ap

Volumes of cancer surgery for breast, colorectal and ovarian cancer 1992–97: is there evidence of increasing sub-specialization by surgeons?

The ‘Calman–Hine Report’ (1995) recommended that cancer surgery should be limited to ‘high-volume’ consultants. Through an analysis of 5 years of Hospital Episode Statistics for the West Midlands region (1992–1997), we have investigated whether there is evidence of increasing numbers of patients with breast, colorectal or ovarian cancer being treated by high throughput, i.e. sub-specialist surgeons, who carry out more than a threshold level of primary cancer resections annually. The proportion of cases treated by the high-volume breast, colorectal and ovarian cancer surgeons increased annually during the 5 years. The absolute number of consultant firms who undertook breast cancer resections reduced during the 5 years; but the number doing colorectal and ovarian surgery increased. Throughout the 5 years, half of the ovarian cancer resections were carried out by consultant firms who did very few procedures – less than 5 of these procedures annually. The relatively high case-load, the elective nature of breast cancer surgery and an early policy change have undoubtedly facilitated the move towards sub-specialization. The weaker trends for colorectal and ovarian cancer surgery suggest continued monitoring is required to ensure that there is a reduction in the proportion of people treated by surgeons who undertake few cancer resections annually. © 2001 Cancer Research Campaign www.bjcancer.co

Science with the World Space Observatory - Ultraviolet

The World Space Observatory-Ultraviolet (WSO-UV) will provide access to the UV range during the next decade. The instrumentation on board will allow to carry out high resolution imaging, high sensitivity imaging, high resolution (R~55000) spectroscopy and low resolution (R~2500) long slit spectroscopy. In this contribution, we briefly outline some of the key science issues that WSO-UV will address during its lifetime. Among them, of special interest are: the study of galaxy formation and the intergalactic medium; the astronomical engines; the Milky Way formation and evol ution, and the formation of the Solar System and the atmospheres of extrasolar p lanets.Comment: Just one text file (aigomezdecastro.tex). To be published in the proceeding of the conference: "New Quest in Stellar Astrophysics II: UV properties of evolved stellar populations" held in Puerto Vallarta - Mexico, in april 200

An investigation into the psychosocial impact of therapeutic recreation summer camp for youth with serious illness and disability

OBJECTIVES: This study aimed to evaluate the impact on emotional, social, physical and educational functioning of a therapeutic recreation camp provided by ‘Over The Wall’, a UK charity for children and young people with chronic illness or disability. METHOD: Two hundred and sixty four people registered to attend camp were sent the Pediatric Quality of Life Inventory version Child Self-Report Scale before camp, immediately after camp, 1 month after camp and 3 months after camp. RESULTS: Of those invited to participate, 178 children completed the pre-camp survey (67% response rate). Of those, 105 completed both the post-camp 1 and pre-camp questionnaires (59% of pre-camp respondents), and 60 of those participants subsequently completed the 1-month post-camp questionnaire as well (34% of pre-camp respondents). Only 32 participants completed the 3-month follow-up data (18% of pre-camp respondents). Across the first three timepoints (pre-Camp, post-Camp and 1 month follow-up), a repeated measures ANOVA indicated a significant improvement in emotional and social functioning, but not physical or school functioning (p < 0.05). Post-hoc analyses on pre-camp and post-camp scores revealed small-medium effect sizes of 0.317 and 0.272 for emotional and social functioning, respectively. DISCUSSION: The therapeutic recreation summer camp provided for children and young people with health challenges had a significant, positive impact on emotional and social functioning. Such camps can therefore be considered as having empirical support for their aims. Further work is warranted to increase the response rate to establish the longer term impact of the camps and the wider impact of the camps on the wider family

Hyperbolicity and the effective dimension of spatially-extended dissipative systems

We show, using covariant Lyapunov vectors, that the chaotic solutions of spatially extended dissipative systems evolve within a manifold spanned by a finite number of physical modes hyperbolically isolated from a set of residual degrees of freedom, themselves individually isolated from each other. In the context of dissipative partial differential equations, our results imply that a faithful numerical integration needs to incorporate at least all physical modes and that increasing the resolution merely increases the number of isolated modes.Comment: 4 pages, 4 figure

Firewalls as a resource for resistance: separating border policing from social service provision in Sweden and the UK

Firewalls separate rights provision for undocumented migrants from the border policing of migration authorities. In this article, we compare how firewalls have been negotiated during recent years in Sweden and the UK. Firewalls have been partly strengthened in the UK as a result of the ‘Windrush scandal’. Simultaneously, firewalls have been increasingly contested in Sweden after the 2015 ‘long summer of migration’ as a result of continuously more repressive migration policies. On the basis of this detailed comparison, we argue that firewalls are a useful conceptual lens to understand migrant struggles and the development of migration policies. Moreover, we suggest that firewalls can be a useful resource for social service providers using their discretion to resist repressive migration governing at different levels and scales and for organizing political work by and for people at risk of deportation

Central African biomes and forest succession stages derived from modern pollen data and plant functional types

New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo) including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs) and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1) modern potential biomes and (2) potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites) and tropical rain forest (TRFO biome) is well identified from tropical seasonal forest (TSFO biome). When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe) evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map should be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO) is well differentiated from the secondary forest (TSFE), but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions