1,932 research outputs found

    Launch window analysis of satellites in high eccentricity or large circular orbits

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    Numerical methods and computer programs for studying the stability and evolution of orbits of large eccentricity are presented. Methods for determining launch windows and target dates are developed. Mathematical models are prepared to analyze the characteristics of specific missions

    Nutritional Aspects of High Altitude and Snow Bound Areas

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    The precise nutritional requirement of humans at high altitude area is not well defined. Further there are many conflicting reports on the effects of hypoxia on digestion, absorption and utilization of food at high altitude. In this review the nutritional requirements at high altitude and the effects of hypoxia on humans in relation to nutrition have been discussed

    4,8-Dimethyl­pyrano[2,3-a]carbazol-2(11H)-one

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    The mol­ecule of the title compound, C17H13NO2, is nearly planar, the r.m.s. deviation for all non-H atoms excluding the two methyl C atoms being 0.089 Å. Inter­molecular N—H⋯O and C—H⋯O hydrogen bonds are found in the crystal structure. C—H⋯π inter­actions are also found. The H atoms of the methyl group attached to the benzene ring are disordered equally over two positions

    Hot Core, Outflows and Magnetic Fields in W43-MM1 (G30.79 FIR 10)

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    We present submillimeter spectral line and dust continuum polarization observations of a remarkable hot core and multiple outflows in the high-mass star-forming region W43-MM1 (G30.79 FIR 10), obtained using the Submillimeter Array (SMA). A temperature of ∼\sim 400 K is estimated for the hot-core using CH3_3CN (J=19-18) lines, with detections of 11 K-ladder components. The high temperature and the mass estimates for the outflows indicate high-mass star-formation. The continuum polarization pattern shows an ordered distribution, and its orientation over the main outflow appears aligned to the outflow. The derived magnetic field indicates slightly super-critical conditions. While the magnetic and outflow energies are comparable, the B-field orientation appears to have changed from parsec scales to ∼\sim 0.1 pc scales during the core/star-formation process.Comment: accepted, ApJ Letter

    Direct Detection of a (Proto)Binary-Disk System in IRAS 20126+4104

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    We report the direct detection of a binary/disk system towards the high-mass (proto)stellar object IRAS20126+4104 at infrared wavengths. The presence of a multiple system had been indicated by the precession of the outflow and the double jet system detected earlier at cm-wavelengths. Our new K, L' & M' band infrared images obtained with the UKIRT under exceptional seeing conditions on Mauna Kea are able to resolve the central source for the first time, and we identify two objects separated by ~ 0.5'' (850 AU). The K and L' images also uncover features characteristic of a nearly edge-on disk, similar to many low mass protostars with disks: two emission regions oriented along an outflow axis and separated by a dark lane. The peaks of the L' & M' band and mm-wavelength emission are on the dark lane, presumably locating the primary young star. The thickness of the disk is measured to be ~ 850 AU for radii < 1000 AU. Approximate limits on the NIR magnitudes of the two young stars indicate a high-mass system, although with much uncertainty. These results are a demonstration of the high-mass nature of the system, and the similarities of the star-formation process in the low-mass and high-mass regimes viz. the presence of a disk-accretion stage. The companion is located along the dark lane, consistent with it being in the equatorial/disk plane, indicating a disk-accretion setting for massive, multiple, star-formation.Comment: 12 pages, 3 figures (1 pseudo colour), 1 table; colour figure replaced with jpg file; to be published in ApJL; (back after temoprary withdrawal due to non-scientific reasons.

    4-Methyl-7,8,9,10-tetra­hydro­cyclo­hepta­[b]indol-6(5H)-one

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    In the title compound, C14H15NO, the seven-membered ring exhibits a slightly distorted twist-boat conformation. The pyrrole ring forms a dihedral angle of 1.44 (10)° with the fused benzene ring. N—H⋯O hydrogen bonds form a centrosymmetric dimer and weak C—H⋯π inter­actions are also found in the crystal structure
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