15,531 research outputs found

    HAT-P-30b: A Transiting Hot Jupiter on a Highly Oblique Orbit

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    We report the discovery of HAT-P-30b, a transiting exoplanet orbiting the V = 10.419 dwarf star GSC 0208-00722. The planet has a period P = 2.810595 ± 0.000005 days, transit epoch Tc = 2455456.46561 ± 0.00037 (BJD), and transit duration 0.0887 ± 0.0015 days. The host star has a mass of 1.24 ± 0.04 M_⊙, radius of 1.21 ± 0.05 R_⊙, effective temperature of 6304 ± 88 K, and metallicity [Fe/H] = +0.13 ± 0.08. The planetary companion has a mass of 0.711 ± 0.028 M J and radius of 1.340 ± 0.065 R J yielding a mean density of 0.37 ± 0.05 g cm^(–3). We also present radial velocity measurements that were obtained throughout a transit that exhibit the Rossiter-McLaughlin effect. By modeling this effect, we measure an angle of λ = 73.°5 ± 9.°0 between the sky projections of the planet's orbit normal and the star's spin axis. HAT-P-30b represents another example of a close-in planet on a highly tilted orbit, and conforms to the previously noted pattern that tilted orbits are more common around stars with T_(eff*) ≳ 6250 K

    Clinical results of entrance dose in vivo dosimetry for high energy photons in external beam radiotherapy using MOSFETs

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    Copyright © 2007 ACPSEM. All rights reserved. The document attached has been archived with permission from the publisher.Thomson and Nielsen TN-502 RD MOSFETs were used for entrance dose in vivo dosimetry for 6 and 10 MV photons. A total of 24 patients were tested, 10 breast, 8 prostate, 5 lung and 1 head and neck. For prostates three fields were checked. For all other plans all fields were checked. An action threshold of 8% was set for any one field and 5% for all fields combined. The total number of fields tested was 56, with a mean discrepancy of 1.4% and S.D. of 2.6%. Breasts had a mean discrepancy of 1.8% and S.D. of 2.8%. Prostates had a mean discrepancy of 1.3% and S.D. of 2.9%. For 3 fields combined, prostates had a mean of 1.3% and S.D. of 1.8%. These results are similar to results obtained with diodes and TLDs for the same techniques.J. P. Morton, M. Bhat, T. Williams and A. Kovend

    Space-Time Variation of Physical Constants and Relativistic Corrections in Atoms

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    Detection of high-redshift absorption in the optical spectra of quasars have provided a powerful tool to measure spatial and temporal variations of physical ``constants'' in the Universe. It is demonstrated that high sensitivity to the variation of the fine structure constant alpha can be obtained from a comparison of the spectra of heavy and light atoms (or molecules). We have performed calculations for the pair FeII and MgII for which accurate quasar and laboratory spectra are available. A possibility of 10510^5 times enhanced effects of the fundamental constants variation suitable for laboratory measurements is also discussed.Comment: 8 pages; LaTeX; Submitted to Phys. Rev. Let

    Ariel - Volume 5 Number 5

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    Editors Mark Dembert J. D. Kanofsky Entertainment Robert Breckenridge Joe Conti Gary Kaskey Photographer Scot Kastner Overseas Editor Mike Sinason Circulation Jay Amsterdam Humorist Jim McCann Staff Ken Jaffe Bob Sklaroff Janet Welsh Dave Jacoby Phil Nimoityn Frank Chervane

    Systematics of the obligate ant-following clade of antbirds (Aves: Passeriformes: Thamnophilidae)

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    © 2014 by the Wilson Ornithological Society. Results of a comprehensive molecular phylogeny of the family Thamnophilidae were consistent with earlier findings that almost all obligate army-ant-followers of the family form a monophyletic group that contains five well-supported clades and encompasses six currently recognized genera: Phaenostictus, Pithys, Willisornis, Gymnopithys, Rhegmatorhina, and Phlegopsis. A comparative analysis of seven suites of morphological, behavioral, and ecological traits within the context of the phylogeny reinforced the validity of five of these genera, but results for the sixth, Gymnopithys, were internally inconsistent and required the description of a new genus, Oneillornis

    Thin-film flow in helically wound rectangular channels with small torsion

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    Laminar gravity-driven thin-film flow down a helically-wound channel of rectangular cross-section with small torsion in which the fluid depth is small is considered. Neglecting the entrance and exit regions we obtain the steady-state solution that is independent of position along the axis of the channel, so that the flow, which comprises a primary flow in the direction of the axis of the channel and a secondary flow in the cross-sectional plane, depends only on position in the two-dimensional cross-section of the channel. A thin-film approximation yields explicit expressions for the fluid velocity and pressure in terms of the free-surface shape, the latter satisfying a non-linear ordinary differential equation that has a simple exact solution in the special case of a channel of rectangular cross-section. The predictions of the thin-film model are shown to be in good agreement with much more computationally intensive solutions of the small-helix-torsion Navier–Stokes equations. The present work has particular relevance to spiral particle separators used in the mineral-processing industry. The validity of an assumption commonly used in modelling flow in spiral separators, namely that the flow in the outer region of the separator cross-section is described by a free vortex, is shown to depend on the problem parameters

    Anthropometric and Performance Characteristics of Elite Hurling Players

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    The purpose of the present study was to examine variations in the anthropometric and performance characteristics of elite hurling players in relation to playing position. Forty-one male, elite intercounty hurlers (25 ± 4 years), 4 goalkeepers, 8 full-backs, 8 halfback, 6 midfielders, 8 half-forwards and 7 full-forwards underwent measurements of standard anthropometric (stature, body mass, sum of five skinfolds and adipose tissue percentage estimates (%AT)) and performance characteristics (counter-movement jump (CMJ), CMJ peak power, CMJ relative peak power, 5-, 10-, 20-m sprint times and estimated V•O2max) during the later stages of the competitive season. A clear hierarchical anthropometric profile is evident with goalkeepers being the taller (184.3 ± 3.7 m), possessing the highest body mass (88.7 ± 5.7 kg) and adiposity (13.2 ± 3.1 %AT) than their outfield colleagues. Half-backs (47.4 ± 2.4 cm) and half-forwards (50.7 ± 5.9 cm) produced the highest CMJ scores; a similar profile was evident for sprint times. Midfielders (60.1 ± 1.4 mL.kg-1.min-1) exhibited a significantly (p<0.05) greater maximal oxygen uptake than all other playing positions. Differences in the anthropometric and performance characteristics of other playing positions whilst evident were non-significant. This study provides novel data, as it is the first report to present normative anthropometric and performance data for elite hurling players which to date has not been present in the literature. The enhanced maximal oxygen uptake in midfield players is likely due to different performance, technical and tactical demands associated with this position
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