7,172 research outputs found

    Improved determination of the WIMP mass from direct detection data

    Full text link
    Direct detection experiments searching for weakly interacting massive particle (WIMP) dark matter typically use a simplified model of the Galactic halo to derive parameter constraints. However, there is strong evidence that this Standard Halo Model is not a good approximation to our Galaxy. We discuss previous attempts to extract the WIMP mass, cross-section and speed distribution from direct detection data and show that these lead to significant biases in the reconstructed parameter values. We develop and test an alternative model-independent method based on parametrising the momentum distribution of the WIMPs. This allows us to limit the analysis only to those regions of momentum space to which the experiments are sensitive. The method can be applied to a single experiment to extract information about the distribution function, as well as information on the degenerate WIMP mass and interaction cross-section combined in a single parameter. This degeneracy can be broken by including data from additional experiments, meaning that the WIMP mass and speed distribution can be recovered. We test the momentum parametrisation method using mock datasets from proposed ton-scale direct detection experiments, showing that it exhibits improved coverage properties over previous methods, as well as significantly reduced bias. We are also able to accurately reconstruct the shape of the WIMP speed distribution but distinguishing between different underlying distributions remains difficult.Comment: 15 pages, 16 figures. VL-2 benchmark velocity distribution modified slightly; corrected typo in XENON1T exposure time; conclusions unchanged. Matches version published in PR

    Axial-flow pump design digital computer program

    Get PDF
    FORTRAN program for computerized design of axial flow pump by blade element analysi

    Ebola and War in the Democratic Republic of Congo: Avoiding Failure and Thinking Ahead

    Get PDF
    The Ebola epidemic in the Democratic Republic of Congo (DRC) is exceptionally dangerous, occurring within active armed conflict and geopolitical volatility, including a million displaced persons. With 421 cases, 240 deaths, and the numbers increasing, this Ebola outbreak is the second deadliest in history. Recent spread to Butembo, home to 1.2 million people, raised concerns. The DRC, World Health Organization (WHO), and partners are leading a vigorous international response, yet despite deploying an experimental vaccine, cases doubled in October 2018 and many cases had unknown origin. Uncontrolled Ebola outbreaks can expand quickly, as occurred in West Africa in 2014. Averting that outcome in the DRC requires rapid action including a strengthened public health response, security, and community outreach. If violence escalates, it could compromise a fragile response. Yet resources are insufficient. The United States and other countries are not permitting personnel deployment to the epicenter, including from the Centers for Disease Control and Prevention (CDC) and US Agency for International Development (USAID). In this Viewpoint, we review recommendations of experts convened by Georgetown University and listed at the end of this article. The United States and international community should launch high-level political mobilization, with diplomatic, human, and economic resources. It is critical to recognize that future health crises will occur in fragile, insecure settings. To prepare, the international community needs long-term planning and enhanced capacities to improve the safety and effectiveness of epidemic response operations

    Developing student’s accounting competencies using Astin’s I-E-O model: an identification of key educational inputs based on Indonesian student perspectives

    Get PDF
    This paper discusses a model for developing Students’ Accounting Competencies (SAC) using Astin’s Input-Environment-Outcome (I-E-O) model. SAC based on AICPA core competency is considered important due to business and environment changes. Student Motivation, Student Previous Achievement, Student Demographic Characteristics, Learning Facilities, and Comfort of Class Size are educational inputs. Student Engagement and SAC are proxies for Environment and Outcome respectively. Empirically, the aforementioned educational inputs except Student Demographic Characteristics are important inputs for improving SAC. Student Engagement effectively mediates the influence of inputs on SAC. The I-E-O model is appropriate for analysing relationships among a single input, Student Engagement, and SAC. This model becomes less powerful for analysing simultaneous relationships among multiple inputs, Student Engagement, and SAC. Future research on using other assessments for gauging SAC, identifying other significant inputs, identifying the impact of real class size on Student Engagement and SAC, and developing Student Engagement for accounting courses are required

    XMM-Newton observation of the interacting galaxies NGC1512 and NGC1510

    Full text link
    The galaxy NGC1512 is interacting with the smaller galaxy NGC1510 and shows a peculiar morphology, characterised by two extended arms immersed in an HI disc whose size is about four times larger than the optical diameter of NGC1512. For the first time we performed a deep X-ray observation of the galaxies NGC1512 and NGC1510 with XMM-Newton to gain information on the population of X-ray sources and diffuse emission in a system of interacting galaxies. We identified and classified the sources detected in the XMM-Newton field of view by means of spectral analysis, hardness-ratios calculated with a Bayesian method, X-ray variability, and cross-correlations with catalogues in optical, infrared, and radio wavelengths. We also made use of archival Swift (X-ray) and Australia Telescope Compact Array (radio) data to better constrain the nature of the sources detected with XMM-Newton. We detected 106 sources in the energy range of 0.2-12 keV, out of which 15 are located within the D_25 regions of NGC1512 and NGC1510 and at least six sources coincide with the extended arms. We identified and classified six background objects and six foreground stars. We discussed the nature of a source within the D_25 ellipse of NGC1512, whose properties indicate a quasi-stellar object or an intermediate ultra-luminous X-ray source. Taking into account the contribution of low-mass X-ray binaries and active galactic nuclei, the number of high-mass X-ray binaries detected within the D_25 region of NGC1512 is consistent with the star formation rate obtained in previous works based on radio, infrared optical, and UV wavelengths. We detected diffuse X-ray emission from the interior region of NGC1512 with a plasma temperature of kT=0.68(0.31-0.87) keV and a 0.3-10 keV X-ray luminosity of 1.3E38 erg/s, after correcting for unresolved discrete sources.Comment: Accepted for publication in Astronomy and Astrophysics. 20 pages. Appendix B will be published electronically onl

    Identification Of Environmental Variables For Use In Monitoring For The Evaluation Of The Rural Environment Protection Scheme

    Get PDF
    Teagasc wishes to acknowledge the support of the Environmental RTDI Programme 2000–2006 in financing this research project.End of project reportThe aim of this study was to identify and select quantitative environmental attributes for a monitoring programme that may be integrated into an environmental evaluation of Ireland’s agri-environmental scheme. This was achieved primarily by reviewing a range of agri-environmental indicators and suggesting indicators that would be appropriate for monitoring the REPS. The study conducted a desk review to collate information on current best practice in monitoring for environmental quality. A Project Group (comprising representatives from the Environmental Protection Agency [EPA], Department of Agriculture and Food [DAF], Teagasc, and the project supervisors) advised on the ongoing development of the project. There was a consultation process with national experts, and with a selection of stakeholder organisations with an interest in monitoring the environmental impact of the REPS.Environmental Protection Agenc

    XMM-Newton observation of SNR J0533-7202 in the Large Magellanic Cloud

    Get PDF
    Aims. We present an X-ray study of the supernova remnant SNR J0533-7202 in the Large Magellanic Cloud (LMC) and determine its physical characteristics based on its X-ray emission. Methods. We observed SNR J0533-7202 with XMM-Newton (flare-filtered exposure times of 18 ks EPIC-pn and 31 ks EPIC-MOS1/MOS2). We produced X-ray images of the SNR, performed an X-ray spectral analysis, and compared the results to multi-wavelength studies. Results. The distribution of X-ray emission is highly non-uniform, with the south-west region brighter than the north-east. The X-ray emission is correlated with the radio emission from the remnant. We determine that this morphology is likely due to the SNR expanding into a non-uniform ambient medium and not an absorption effect. We estimate the size to be 53.9 (\pm 3.4) x 43.6 (\pm 3.4) pc, with the major axis rotated ~64 degrees east of north. We find no spectral signatures of ejecta and infer that the X-ray plasma is dominated by swept-up interstellar medium. Using the spectral fit results and the Sedov self-similar solution, we estimate an age of ~17-27 kyr, with an initial explosion energy of (0.09-0.83) x 10^51 erg. We detected an X-ray source located near the centre of the remnant, namely XMMU J053348.2-720233. The source type could not be conclusively determined due to the lack of a multi-wavelength counterpart and low X-ray counts. We find that it is likely either a background active galactic nucleus or a low-mass X-ray binary in the LMC. Conclusions. We detected bright thermal X-ray emission from SNR J0533-7202 and determined that the remnant is in the Sedov phase of its evolution. The lack of ejecta emission prohibits us from typing the remnant with the X-ray data. Therefore, the likely Type Ia classification based on the local stellar population and star formation history reported in the literature cannot be improved upon.Comment: 7 pages, 4 figures, accepted for publication in Astronomy and Astrophysic

    Emotional and behavioral reaction to intrusive thoughts.

    Get PDF
    A self-report measure of the emotional and behavioral reactions to intrusive thoughts was developed. The article presents data that confirm the stability, reliability, and validity of the new seven-item measure. Emotional and behavioral reactions to intrusions emerged as separate factors on the Emotional and Behavioral Reactions to Intrusions Questionnaire (EBRIQ), a finding confirmed by an independent stress study. Test-retest reliability over 30 to 70 days was good. Expected relationships with other constructs were significant. Stronger negative responses to intrusions were associated with lower mindfulness scores and higher ratings of experiential avoidance, thought suppression, and intensity and frequency of craving. The EBRIQ will help explore differences in reactions to intrusive thoughts in clinical and nonclinical populations, and across different emotional and behavioral states. It will also be useful in assessing the effects of therapeutic approaches such as mindfulness

    Strategic Outsourcing: Evidence from the British Companies

    Get PDF
    Outsourcing has become an increasingly popular option for many organisations. But they vary in terms of activities being outsourced, reasons for and benefits from outsourcing, and how the decision was made. This article presents an empirical research on fourteen companies. It found out, a) in most cases it was the ‘peripheral’ support activity being outsourced with cost reduction as the primary driver; b) outsourcing decision was being made early in the process without active involvement of the in-house provider; and c) there were problems in supplier selection and management. The research identified pre-outsourcing decision process and post-outsourcing management as the two key areas that gave cause for concern, and offered recommendations for improvement
    corecore