330 research outputs found

    Relationship Between Selected Predictor Variables and Perceived Job Satisfaction of Oklahoma Public School Superintendents

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    Educational Administratio

    Aspects of Tragedy in the Theatre of Eugene Ionesco.

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    Buoyant AGN bubbles in the quasi-isothermal potential of NGC 1399

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    The Fornax Cluster is a low-mass cool-core galaxy cluster. We present a deep {\sl Chandra} study of NGC 1399, the central dominant elliptical galaxy of Fornax. The cluster center harbors two symmetric X-ray cavities coincident with a pair of radio lobes fed by two collimated jets along a north-south axis. A temperature map reveals that the AGN outburst has created a channel filled with cooler gas out to a radius of 10 kpc. The cavities are surrounded by cool bright rims and filaments that may have been lifted from smaller radii by the buoyant bubbles. X-ray imaging suggests a potential ghost bubble of ≳\gtrsim 5\,kpc diameter to the northwest. We find that the amount of gas lifted by AGN bubbles is comparable to that which would otherwise cool, demonstrating that AGN driven outflow is effective in offsetting cooling in low-mass clusters. The cluster cooling time scale is >30>30 times longer than the dynamical time scale, which is consistent with the lack of cold molecular gas at the cluster center. The X-ray hydrostatic mass is consistent within 10\% with the total mass derived from the optical data. The observed entropy profile rises linearly, following a steeper slope than that observed at the centers of massive clusters; gas shed by stars in NGC 1399 may be incorporated in the hot phase. However, it is far-fetched for supernova-driven outflow to produce and maintain the thermal distribution in NGC 1399 and it is in tension with the metal content in the hot gas.Comment: 11 pages, 6 figures, Matches the version published in Ap

    Upgrades to the International Space Station Urine Processor Assembly

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    The ISS Urine Processor Assembly (UPA) began operations in November 2008. Though the UPA has successfully generated distillate from crew urine, several modifications and upgrades have been implemented to improve overall system performance throughout the years. Current and future upgrades to the UPA will continue to focus on improved system performance and reliability, focusing primarily on the Distillation Assembly and upgrades to the UPA vacuum pump. Work towards a flight demonstration experiment of a vacuum pump utilizing scroll pump technologies has also continued forward. The following paper discusses progress on these various concepts, including the implementation of a more reliable drive belt, improved methods for managing condensate in the stationary bowl of the Distillation Assembly, installation of improved centrifuge bearings, implementation of a liquid level sensor, and upgrades to the UPA vacuum pump

    Availability of long-acting and permanent family-planning methods leads to increase in use in conflict-affected northern Uganda: evidence from cross-sectional baseline and endline cluster surveys

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    Humanitarian assistance standards require specific attention to address the reproductive health (RH) needs of conflict-affected populations. Despite these internationally recognised standards, access to RH services is still often compromised in war. We assessed the effectiveness of our programme in northern Uganda to provide family planning (FP) services through mobile outreach and public health centre strengthening. Baseline (n=905) and endline (n=873) cross-sectional surveys using a multistage cluster sampling design were conducted in the catchment areas of four public health centres in 2007 and 2010. Current use of any modern FP method increased from 7.1% to 22.6% (adjusted odds ratio [OR] 3.34 [95% confidence interval (CI) 2.27–4.92]); current use of long-acting and permanent methods increased from 1.2% to 9.8% (adjusted OR 9.45 [95%CI 3.99–22.39]). The proportion of women with unmet need for FP decreased from 52.1% to 35.7%. This study demonstrates that when comprehensive FP services are provided among conflict-affected populations, women will choose to use them. The combination of mobile teams and health systems strengthening can make a full range of methods quickly available while supporting the health system to continue to provide those services in challenging and resource-constrained settings

    Elemental Abundances in the X-Ray Gas of Early-Type Galaxies with XMM and Chandra Observations

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    The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the metallicity of the gas toward the inner part of the galaxy, which can be tested by measuring the gas phase abundances. We use high-quality data for 10 nearby early-type galaxy from XMM-Newton, featuring both the EPIC and the Reflection Grating Spectrometer, where the strongest emission lines are detected with little blending; some Chandra data are also used. We find excellent consistency in the elemental abundances between the different XMM instruments and good consistency with Chandra. Differences in abundances with aperture size and model complexity are examined, but large differences rarely occur. For a two-temperature thermal model plus a point source contribution, the median Fe and O abundances are 0.86 and 0.44 of the Solar value, while Si and Mg abundances are similar to that for Fe. This is similar to stellar abundances for these galaxies but supernovae were expected to enhance the gas phase abundances considerably, which is not observed.Comment: 35 pages, 10 figures, accepted for publication in Astrophysical Journa
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