6,028 research outputs found

    ATD-2 Integrated Arrival/Departure/Surface (IADS) System Specification - Phase 2

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    The purpose of this document is to capture the core capabilities developed in ATD-2 Phase 2

    Sodium Atoms in the Lunar Exotail: Observed Velocity and Spatial Distributions

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    The lunar sodium tail extends long distances due to radiation pressure on sodium atoms in the lunar exosphere. Our earlier observations measured the average radial velocity of sodium atoms moving down the lunar tail beyond Earth (i.e., near the anti-lunar point) to be ~ 12.5 km/s. Here we use the Wisconsin H-alpha Mapper to obtain the first kinematically resolved maps of the intensity and velocity distribution of this emission over a 15 x 15 deg region on the sky near the anti-lunar point. We present both spatially and spectrally resolved observations obtained over four nights bracketing new Moon in October 2007. The spatial distribution of the sodium atoms is elongated along the ecliptic with the location of the peak intensity drifting 3 deg east along the ecliptic per night. Preliminary modeling results suggest the spatial and velocity distributions in the sodium exotail are sensitive to the near surface lunar sodium velocity distribution. Future observations of this sort along with detailed modeling offer new opportunities to describe the time history of lunar surface sputtering over several days

    Regeneration revival? Making housing-led regeneration work across England

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    This report contains findings from a study into housing led regeneration. The report addressed three questions: What are the potential benefits of housing-led regeneration in the current context? What types of housing-led regeneration projects are currently occurring? What lessons can be learned from current housing-led regeneration projects and the barriers they face? The study found the positive benefits of regeneration expenditure and provide a series of lessons to policy makers and practitioners

    Filamentary Accretion Flows in the Embedded Serpens South Protocluster

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    One puzzle in understanding how stars form in clusters is the source of mass -- is all of the mass in place before the first stars are born, or is there an extended period when the cluster accretes material which can continuously fuel the star formation process? We use a multi-line spectral survey of the southern filament associated with the Serpens South embedded cluster-forming region in order to determine if mass is accreting from the filament onto the cluster, and whether the accretion rate is significant. Our analysis suggests that material is flowing along the filament's long axis at a rate of ~30Msol/Myr (inferred from the N2H+ velocity gradient along the filament), and radially contracting onto the filament at ~130Msol/Myr (inferred from HNC self-absorption). These accretion rates are sufficient to supply mass to the central cluster at a similar rate to the current star formation rate in the cluster. Filamentary accretion flows may therefore be very important in the ongoing evolution of this cluster.Comment: 19 pages, 8 figures, 2 tables; accepted for publication in Ap

    Determination of Additives in Cigarettes Utilizing Evolved Gas Analysis (EGA)

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    While additives to consumer products must be listed in order by amount, it is not required to report the actual amounts of these additives. Given that impacts on human health are dose dependent, knowledge of additive amounts would aid discussions of the safety of these compounds for inhalation. Additives for cigarettes include flavors, such as menthol, and propylene glycol, a humectant. Rapid determination of the amounts of menthol and propylene glycol additives in cigarettes was accomplished utilizing evolved gas analysis (EGA) – gas chromatography (GC) – flame ionization detection (FID). Careful preparation of samples and appropriate sample storage are critical components to this study. Menthol amounts in cigarettes were consistent with previous studies and this represents the first report of propylene glycol amounts

    Linking Forests and Economic Well-being: A Four Quadrant Approach

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    This paper has three main objectives: (1) to investigate whether the four-quadrant approach introduced by Maini (2003) reveals a useful typology for grouping countries by GDP and forest cover per capita, (2) to determine if the framework can enhance our understanding of the relationship between forest cover and GDP per capita, and (3) to investigate why countries in the four-quadrant world occupy different quadrants, and to determine the principal factors affecting country-movement across and within the individual quadrants. The examination reveals that countries can be classified into four broad categories, and that GDP and forest cover per capita have a low but consistent level of negative association. After regressing economic, institutional, social capital and other variables on a country’s occupancy and movement in the four-quadrant world, the results suggest that countries in each quadrant share different characteristics and that factors underlying country-movement varies according to the quadrant being observed. Overall, countries with less corruption and higher education are likely to experience increases in both forest cover and GDP per capita, while countries exporting a significant proportion of forest products have a reduced probability of increasing both variables.Economic well-being, forest cover, institutions, corruption, education

    On the Evaluation of Silicon Photomultipliers for Use as Photosensors in Liquid Xenon Detectors

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    Silicon photomultipliers (SiPMs) are potential solid-state alternatives to traditional photomultiplier tubes (PMTs) for single-photon detection. In this paper, we report on evaluating SensL MicroFC-10035-SMT SiPMs for their suitability as PMT replacements. The devices were successfully operated in a liquid-xenon detector, which demonstrates that SiPMs can be used in noble element time projection chambers as photosensors. The devices were also cooled down to 170 K to observe dark count dependence on temperature. No dependencies on the direction of an applied 3.2 kV/cm electric field were observed with respect to dark-count rate, gain, or photon detection efficiency.Comment: This is an author-created, un-copyedited version of an article accepted for publication/published in Journal of Instrumentation. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1748-0221/13/03/C0304

    Crime, policing and social order: on the expressive nature of public confidence in policing

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    Public confidence in policing is receiving increasing attention from UK social scientists and policy-makers. The criminal justice system relies on legitimacy and consent to an extent unlike other public services: public support is vital if the police and other criminal justice agencies are to function both effectively and in accordance with democratic norms. Yet we know little about the forms of social perception that stand prior to public confidence and police legitimacy. Drawing on data from the 2003/2004 British Crime Survey and the 2006/2007 London Metropolitan Police Safer Neighbourhoods Survey, this paper suggests that people think about their local police in ways less to do with the risk of victimization (instrumental concerns about personal safety) and more to do with judgments of social cohesion and moral consensus (expressive concerns about neighbourhood stability, cohesion and loss of collective authority). Across England and Wales the police may not primarily be seen as providers of a narrow sense of personal security, held responsible for crime and safety. Instead the police may stand as symbolic 'moral guardians' of social stability and order, held responsible for community values and informal social controls. We also present evidence that public confidence in the London Metropolitan Police Service expresses broader social anxieties about long-term social change. We finish our paper with some thoughts on a sociological analysis of the cultural place of policing: confidence (and perhaps ultimately the legitimacy of the police) might just be wrapped up in broader public concerns about social order and moral consensus
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