Using effective temperature and metallicity derived from SDSS spectra for image60,000 F- and G-type main-sequence stars, we develop polynomial models for estimating these parameters from the SDSS ...image and image colors. These photometric estimates have similar error properties as those determined from SDSS spectra. We apply this method to SDSS photometric data for over 2 million F/G stars and measure the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, which correspond to disk and halo. The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component is spatially invariant, while the median disk metallicity smoothly decreases with distance from the Galactic plane from -0.6 at 500 pc to -0.8 beyond several kiloparsecs. The absence of a correlation between metallicity and kinematics for disk stars is in a conflict with the traditional decomposition in terms of thin and thick disks. We detect coherent substructures in the kinematics-metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of image, with an rms scatter of only image0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper-motion measurements accurate to image0.5 mas yr super(-1), for about 200 million F/G dwarf stars within a distance limit of image100 kpc.
We study Milky Way kinematics using a sample of 18.8 million main-sequence stars with r < 20 and proper-motion measurements derived from Sloan Digital Sky Survey (SDSS) and POSS astrometry, including ...{approx}170,000 stars with radial-velocity measurements from the SDSS spectroscopic survey. Distances to stars are determined using a photometric-parallax relation, covering a distance range from {approx}100 pc to 10 kpc over a quarter of the sky at high Galactic latitudes (|b|>20{sup 0}). We find that in the region defined by 1 kpc <Z< 5 kpc and 3 kpc <R< 13 kpc, the rotational velocity for disk stars smoothly decreases, and all three components of the velocity dispersion increase, with distance from the Galactic plane. In contrast, the velocity ellipsoid for halo stars is aligned with a spherical coordinate system and appears to be spatially invariant within the probed volume. The velocity distribution of nearby (Z < 1 kpc) K/M stars is complex, and cannot be described by a standard Schwarzschild ellipsoid. For stars in a distance-limited subsample of stars (<100 pc), we detect a multi-modal velocity distribution consistent with that seen by HIPPARCOS. This strong non-Gaussianity significantly affects the measurements of the velocity-ellipsoid tilt and vertex deviation when using the Schwarzschild approximation. We develop and test a simple descriptive model for the overall kinematic behavior that captures these features over most of the probed volume, and can be used to search for substructure in kinematic and metallicity space. We use this model to predict further improvements in kinematic mapping of the Galaxy expected from Gaia and the Large Synoptic Survey Telescope.
Two carbon adsorbents, Ambersorb-600 and Ambersorb-563 (A-600 and A-563), were compared for vapor-phase trichloroethylene (TCE) adsorption from humid air streams. These adsorbents retained capacity ...for TCE in humid environments and were regenerable in situ. Enhanced desorption, and hence, increased working capacities, were achieved with bimodal pore size distributions and hydrophobic surface chemistry. Vapor-phase TCE isotherms confirmed that both of these adsorbents have high capacities for TCE. Only a small difference between the micropore size distributions of A-563 and A-600 was determined by room-temperature methyl chloride adsorption and the modified Horvath−Kawazoe model. Besides differences in particle size and pore volume there was a measurable, but small change, in the fraction of the pores in the ultramicropore range (5 Å or smaller) of the A-600 adsorbent versus that of A-563. In packed-bed breakthrough curve experiments, A-600 displayed a sharper mass-transfer zone than A-563, but maintained essentially the same capacity for TCE in a humid environment. Both materials were amenable to in-situ regeneration, and the A-600 a provided higher overall working capacity than that of A-563.
Space-Savvy Teams on Call Sauer, Jeremy; Bushong, James; Klock, Kenneth
Army,
12/2022, Letnik:
72, Številka:
12
Trade Publication Article
...the Joint Staff identified these teams as part of the new command's initial operating capability in its April 5, 2019, order providing guidance for establishing Space Command. According to the ...Joint Space Integration Terms of Reference, co-signed by Space Force and Space Command on Sept. 17, 2021, the Space Force organizes, trains, equips and provides service components to combatant commands to support warfighting, while JISTs facilitate planning, operations, exercises and security cooperation. ...JISTs are Space Command's forward-deployed space integrators and problem-solvers at the strategic level. ...Army space is a combat multiplier and provides warfighters with a decisive advantage.
We present limits on transit timing variations and secondary eclipse depth variations at 8 microns with the Spitzer Space Telescope IRAC camera. Due to the weak limb darkening in the infrared and ...uninterrupted observing, Spitzer provides the highest accuracy transit times for this bright system, in principle providing sensitivity to secondary planets of Mars mass in resonant orbits. Finally, the transit data provides tighter constraints on the wavelength-dependent atmospheric absorption by the planet.
Thesis (Master of Architecture)--University of Cincinnati, 2005.
Title from electronic thesis title page (viewed Feb. 11, 2006). Includes abstract. Includes bibliographical references.
Manufacturing engineers and shop owners use reduced cycle time as the primary justification for buying new equipment. Over the years, the machine tool industry has directed its efforts toward faster, ...more efficient, and powerful equipment. However, as cycle times decrease from greater feeds and speeds, the percentage of out-of-cut machine time increases. Increased emphasis on just-in-time manufacturing, shorter product life, and more attention to inventory management has resulted in shorter production runs and, consequently, more frequent set-ups. Machine tool builders consider 3 areas when designing for quick set-ups: 1. getting the tools in and out of the turret, 2. setting the tools to the proper offset, and 3. identifying the z datum location of the workpiece in the workholding device.
We present limits on transit timing variations and secondary eclipse depth variations at 8 microns with the Spitzer Space Telescope IRAC camera. Due to the weak limb darkening in the infrared and ...uninterrupted observing, Spitzer provides the highest accuracy transit times for this bright system, in principle providing sensitivity to secondary planets of Mars mass in resonant orbits. Finally, the transit data provides tighter constraints on the wavelength- dependent atmospheric absorption by the planet.
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