Assessment of Unsteady Propagation Characteristics and Corrections in Aeroacoustic Wind Tunnels Using an Acoustic Pulse

Two types of aeroacoustic wind tunnel test section configurations have been tested in the NASA Langley Quiet Flow Facility. The first is a more traditional open-jet configuration, where test section flow passes unbounded through the facility anechoic chamber. The second is the more recent Kevlar wall configuration, where a tensioned Kevlar sheet bounds the test section flow from the facility anechoic chamber. For both configurations, acoustic instrumentation is in the surrounding quiescent space. Both configurations are evaluated with a laser-based pulsed acoustic source, which provides unique capability for assessing the facility unsteady acoustic propagation characteristics. Metrics based on the wander and spread of the pulses are evaluated and show that measurements using Kevlar walls experience dramatically reduced unsteady effects when compared to the open-jet configuration. This leads to a corresponding improvement in coherence between microphones with the Kevlar configuration. Corrections for magnitude and phase for propagation through Kevlar as compared to open-jet propagation are calculated. While limitations in the experimental setup make quantitative analysis difficult, qualitative analysis shows Kevlar magnitude corrections similar to those determined in previous literature. Directivity effects beyond those already present for open-jet configurations are minimal. Phase corrections relative to open-jet configurations are indeterminate within the limitations of the experiment, though data suggest such corrections are not extreme. The background noise produced by the Kevlar is found to be its one drawback when compared with the open-jet configuration, showing significantly greater levels at high frequencies

The RMS Survey: Far-Infrared Photometry of Young Massive Stars

Context: The Red MSX Source (RMS) survey is a multi-wavelength campaign of follow-up observations of a colour-selected sample of candidate massive young stellar objects (MYSOs) in the galactic plane. This survey is returning the largest well-selected sample of MYSOs to date, while identifying other dust contaminant sources with similar mid-infrared colours including a large number of new ultra-compact (UC)HII regions. Aims:To measure the far-infrared (IR) flux, which lies near the peak of the spectral energy distribution (SED) of MYSOs and UCHII regions, so that, together with distance information, the luminosity of these sources can be obtained. Methods:Less than 50% of RMS sources are associated with IRAS point sources with detections at 60 micron and 100 micron, though the vast majority are visible in Spitzer MIPSGAL or IRAS Galaxy Atlas (IGA) images. However, standard aperture photometry is not appropriate for these data due to crowding of sources and strong spatially variable far-IR background emission in the galactic plane. A new technique using a 2-dimensional fit to the background in an annulus around each source is therefore used to obtain far-IR photometry for young RMS sources. Results:Far-IR fluxes are obtained for a total of 1113 RMS candidates identified as young sources. Of these 734 have flux measurements using IGA 60 micron and 100 micron images and 724 using MIPSGAL 70 micron images, with 345 having measurements in both data sets.Comment: 10 pages, 10 figures, 2 Tables, accepted to A&A. A full version of table 1 is available from the lead author or at the CDS upon publicatio

Awareness of lifestyle and colorectal cancer risk:findings from the BeWEL study

It is estimated that 47% of colorectal cancers (CRC) could be prevented by appropriate lifestyles. This study aimed to identify awareness of the causes of CRC in patients who had been diagnosed with a colorectal adenoma through the Scottish Bowel Screening Programme and subsequently enrolled in an intervention trial (using diet and physical activity education and behavioural change techniques) (BeWEL). At baseline and 12-month follow-up, participants answered an open-ended question on factors influencing CRC development. Of the 329 participants at baseline, 40 (12%) reported that they did not know any risk factors and 36 (11%) failed to identify specific factors related to diet and activity. From a potential knowledge score of 1 to 6, the mean score was 1.5 (SD 1.1, range 0 to 5) with no difference between intervention and control groups. At follow-up, the intervention group had a significantly greater knowledge score and better weight loss, diet, and physical activity measures than the control group. Awareness of relevant lifestyle factors for CRC remains low in people at increased risk of the disease. Opportunities within routine NHS screening to aid the capability (including knowledge of risk factors) of individuals to make behavioural changes to reduce CRC risk deserve exploration.Additional co-author: The BeWEL team. The BeWEL Team consists of Shaun Treweek, Fergus Daly, Jill Belch, Jackie Rodger, Alison Kirk, Anne Ludbrook, Petra Rauchhaus, Patricia Norwood, Joyce Thompson, and Jane Wardle

The RMS Survey: The Bolometric Fluxes and Luminosity Distributions of Young Massive Stars

Context: The Red MSX Source (RMS) survey is returning a large sample of massive young stellar objects (MYSOs) and ultra-compact (UC) \HII{} regions using follow-up observations of colour-selected candidates from the MSX point source catalogue. Aims: To obtain the bolometric fluxes and, using kinematic distance information, the luminosities for young RMS sources with far-infrared fluxes. Methods: We use a model spectral energy distribution (SED) fitter to obtain the bolometric flux for our sources, given flux data from our work and the literature. The inputs to the model fitter were optimised by a series of investigations designed to reveal the effect varying these inputs had on the resulting bolometric flux. Kinematic distances derived from molecular line observations were then used to calculate the luminosity of each source. Results: Bolometric fluxes are obtained for 1173 young RMS sources, of which 1069 have uniquely constrained kinematic distances and good SED fits. A comparison of the bolometric fluxes obtained using SED fitting with trapezium rule integration and two component greybody fits was also undertaken, and showed that both produce considerable scatter compared to the method used here. Conclusions: The bolometric flux results allowed us to obtain the luminosity distributions of YSOs and UC\HII{} regions in the RMS sample, which we find to be different. We also find that there are few MYSOs with L $\geq$ 10$^{5}$\lsol{}, despite finding many MYSOs with 10$^{4}$\lsol{} $\geq$ L $\geq$ 10$^{5}$\lsol{}.Comment: 12 pages, 12 figures, 3 tables, accepted to A&A. The full versions of tables 1 and 2 will be available via the CDS upon publicatio

A combined field/remote sensing approach for characterizing landslide risk in coastal areas

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Understanding the key factors controlling slope failure mechanisms in coastal areas is the first and most important step for analyzing, reconstructing and predicting the scale, location and extent of future instability in rocky coastlines. Different failure mechanisms may be possible depending on the influence of the engineering properties of the rock mass (including the fracture network), the persistence and type of discontinuity and the relative aspect or orientation of the coastline. Using a section of the North Coast of Cornwall, UK, as an example we present a multi-disciplinary approach for characterizing landslide risk associated with coastal instabilities in a blocky rock mass. Remotely captured terrestrial and aerial LiDAR and photogrammetric data was interrogated using Geographic Information System (GIS) techniques to provide a framework for subsequent analysis, interpretation and validation. The remote sensing mapping data was used to define the rock mass discontinuity network of the area and to differentiate between major and minor geological structures controlling the evolution of the North Coast of Cornwall. Kinematic instability maps generated from aerial LiDAR data using GIS techniques and results from structural and engineering geological surveys are presented. With this method, it was possible to highlight the types of kinematic failure mechanism that may generate coastal landslides and highlight areas that are more susceptible to instability or increased risk of future instability. Multi-temporal aerial LiDAR data and orthophotos were also studied using GIS techniques to locate recent landslide failures, validate the results obtained from the kinematic instability maps through site observations and provide improved understanding of the factors controlling the coastal geomorphology. The approach adopted is not only useful for academic research, but also for local authorities and consultancy's when assessing the likely risks of coastal instability

Identification and analysis of large paleo-landslides at Mount Burnaby, British Columbia

This is the author accepted manuscript. The final version is available from Geological Society of America via the DOI in this recordThis paper presents a multi-scale and multidisciplinary study of large, late Pleistocene or early Holocene slumps in Eocene sedimentary rocks at Mount Burnaby, just east of Vancouver, British Columbia (BC). Airborne LiDAR and field data were integrated into a GIS to understand the origin, kinematics, and subsequent history of the landslides. Products derived from the bare-earth LiDAR data include an engineering geomorphology map, shaded relief maps, and several LiDAR slope profiles. To understand the landslides better, we analyzed discontinuities and structural lineaments. The structure of the Eocene rocks underlying Mount Burnaby was compared with trends of local lineaments, and the shape of the coastline of Burrard Inlet and Indian Arm, and trends of regional faults and lineaments identified by previous researchers working in southwest BC. Two main joint systems likely played a key role in conditioning the north slope of Mount Burnaby for failure. The landslides probably happened during or soon after deglaciation of the area at the end of the Pleistocene on the steep north face of Mount Burnaby after a 200-m fall in relative sea level caused by glacio-isostatic uplift of the crust.We are grateful to BGC Engineering for its support of our research, and in particular acknowledge Alex Baumgard, who helped us secure LiDAR imagery and funding that allowed us to undertake the project. The research was supported with grants provided by Kinder Morgan Canada and the Natural Sciences and Engineering Research Council of Canada (NSERC Discovery Grants to ds and jjc)

Meeting the challenges of recruitment to multicentre, community-based, lifestyle-change trials : a case study of the BeWEL trial

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