6,143 research outputs found

    Energy conversion apparatus Patent

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    Direct conversion of thermal energy into electrical energy using crossed electric and magnetic field

    The host galaxy of the z=2.4 radio-loud AGN MRC 0406-244 as seen by HST

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    We present multicolour Hubble Space Telescope images of the powerful z=2.4 radio galaxy MRC 0406-244 and model its complex morphology with several components including a host galaxy, a point source, and extended nebular and continuum emission. We suggest that the main progenitor of this radio galaxy was a normal, albeit massive (M ~10^{11} solar masses), star-forming galaxy. The optical stellar disc of the host galaxy is smooth and well described by a S\'ersic profile, which argues against a recent major merger, however there is also a point-source component which may be the remnant of a minor merger. The half-light radius of the optical disc is constrained to lie in the range 3.5 to 8.2kpc, which is of similar size to coeval star forming galaxies. Biconical shells of nebular emission and UV-bright continuum extend out from the host galaxy along the radio jet axis, which is also the minor axis of the host galaxy. The origin of the continuum emission is uncertain, but it is most likely to be young stars or dust-scattered light from the AGN, and it is possible that stars are forming from this material at a rate of 200^{+1420}_{-110} solar masses per year.Comment: Accepted for publication in MNRA

    Element geochemistry of Cherokee Group coals (Middle Pennsylanian) from south-central and southeastern Iowa

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    Middle Pennsylvanian Cherokee Group coals from south-central and southeastern Iowa are typical high-sulfur, high-ash coals. These coals have an arithmetic mean sulfur content of 5.8 percent and a mean ash content of 15.9 percent. Apparent rank for most samples is high-volatile C bituminous coal. The relatively high contents of sulfur and 23 other elements in Iowa Cherokee Group coals are related to near neutral pH conditions (6-8) in the depositional and early diagenetic environments, and to post-depositional epigenetic sphalerite/calcite/pyrite/ kaolinite/barite mineralization. Changes from an aluminosilicate- to a sulfide-element association for U, Mo, Cr, and V, and an increase in element content for U, Mo, Cr, V, Na, Mg, and K in stratigraphically higher coals are thought to be related to differences in depositional environments of the coal-associated rocks, which change from predominantly terrestrial in the Lower Cherokee Group, to predominantly marine in the upper part of the Upper Cherokee Group. Coals overlain by marine, phosphatic, black shale lithologies have the highest content of U, Mo, Ag, Sb, Se, and V

    Hydrogen Two-Photon Continuum Emission from the Horseshoe Filament in NGC 1275

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    Far ultraviolet emission has been detected from a knot of Halpha emission in the Horseshoe filament, far out in the NGC 1275 nebula. The flux detected relative to the brightness of the Halpha line in the same spatial region is very close to that expected from Hydrogen two-photon continuum emission in the particle heating model of Ferland et al. (2009) if reddening internal to the filaments is taken into account. We find no need to invoke other sources of far ultraviolet emission such as hot stars or emission lines from CIV in intermediate temperature gas to explain these data.Comment: 9 pages, 8 figures. Accepted for publication in MNRA

    Rotational and intrinsic levels in Tm169 and Lu175

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    Nuclear levels in Tm169 excited by electron capture of Yb169, and levels in Lu175 excited by both beta decay of Yb175 and electron capture of Hf175 have been studied by using the curved-crystal gamma-ray spectrometer and the ring-focusing beta-ray spectrometer, as well as a semicircular beta-ray spectrometer for low energies. From the precision energies and the multipolarity determinations, the levels in Tm169 have the following energies in kev, and spin and parity assignments: A (ground state) (½+), B 8.42 (3/2+), C 118.20 (5/2+), D 138.95 (7/2+), E 316.19 (7/2+), F 379.31 (7/2-), G 472.91 (9/2-). Levels A, B, C, and D are members of a rotational band whose characteristic constants are given. Levels E and F are interpreted as particle excitations and level G as a rotational level based on the state F. The Lu175 excited states have the following energies in kev, spins, and parities: A (ground state) (7/2+), B 113.81 (9/2+), C 251.46 (11/2+), D 343.40 (5/2+), E 396.31 (9/2-), F 432.76 (7/2+), G 504.7 (1/2+). A, B, and C form a rotational band for which the characteristic constants are given. Some features of the levels and transition probabilities are discussed and compared with the unified model. A brief survey of second-order rotational energy constants and of intrinsic excitation levels is given
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