2,178 research outputs found
Triple point determinations of monomethylhydrazine and nitrogen tetroxide, 2.2 percent by weight nitric oxide
A series of tests was performed to ascertain the triple points of monomethylhydrazine and nitrogen tetroxide. A laboratory method indicated a triple point for monomethylhydrazine, but tests in a large vacuum chamber indicated that a triple point does not occur in spacelike conditions because the mono-methylhydrazine tends to supercool. Instead, an effective freezing point (with agitation) was obtained. New experimental values for liquid monomethylhydrazine vapor pressure were determined for temperatures from 275.2 to 207.6 K. The values were used to derive vapor pressure equations. Tentative values were obtained for the effective freezing point of nitrogen tetroxide spacelike conditions
Leo V: A Companion of a Companion of the Milky Way Galaxy
We report the discovery of a new Milky Way dwarf spheroidal galaxy in the
constellation of Leo identified in data from the Sloan Digital Sky Survey. Leo
V lies at a distance of about 180 kpc, and is separated by about 3 degrees from
another recent discovery, Leo IV. We present follow-up imaging from the Isaac
Newton Telescope and spectroscopy from the Hectochelle fiber spectrograph at
the Multiple Mirror Telescope. Leo V's heliocentric velocity is 173.4 km/s,
which is offset by about 40 km/s from that of Leo IV. A simple interpretation
of the kinematic data is that both objects may lie on the same stream, though
the implied orbit is only modestly eccentric (e = 0.2)Comment: Submitted to ApJ (Letters
G03-1501 Prudent Use of Antibiotics in Companion Animals
This NebGuide explains why antibiotics must be used with care and how to prudently use antibiotics to treat companion animals.
Antibiotics are used to improve animal health and performance. You, as the animal owner or caregiver, make important decisions about how antibiotics are finally used in companion animals. Antibiotics should be used prudently to ensure they are effective and will continue to benefit man and animals in the future. Are you prepared to make the best decisions about using antibiotics in animals
G03-1485 Guidelines for the Prudent Use of Antibiotics in Food Animals
This NebGuide explains why antibiotics must be used with care and how to prudently use antibiotics to treat food animals.
Antibiotics are used to improve animal health and productivity. You, the animal caregiver, make important decisions about how antibiotics are finally used in food producing animals. Antibiotics should be used prudently to ensure they are effective, do not leave residues in food, and will continue to benefit man and animals in the future. Are you prepared to make the best decisions about using antibiotics in animals
Luminous X-Ray Sources in Arp 147
The Chandra X-Ray Observatory was used to image the collisional ring galaxy
Arp 147 for 42 ks. We detect 9 X-ray sources with luminosities in the range of
1.4 - 7 x 10^{39} ergs/sec in or near the blue knots of star formation
associated with the ring. A source with an isotropic X-ray luminosity of 1.4 x
10^{40} ergs/sec is detected in the nuclear region of the intruder galaxy.
X-ray sources associated with a foreground star and a background quasar are
used to improve the registration of the X-ray image with respect to HST high
resolution optical images. The intruder galaxy, which apparently contained
little gas before the collision, shows no X-ray sources other than the one in
the nuclear bulge which may be a poorly fed supermassive black hole. These
observations confirm the conventional wisdom that collisions of gas rich
galaxies trigger large rates of star formation which, in turn, generate
substantial numbers of X-ray sources, some of which have luminosities above the
Eddington limit for accreting stellar-massComment: 9 pages, 5 figure
A New Method for Searching for Free Fractional Charge Particles in Bulk Matter
We present a new experimental method for searching for free fractional charge
in bulk matter; this new method derives from the traditional Millikan liquid
drop method, but allows the use of much larger drops, 20 to 100 mm in diameter,
compared to the traditional method that uses drops less than 15 mm in diameter.
These larger drops provide the substantial advantage that it is then much
easier to consistently generate drops containing liquid suspensions of powdered
meteorites and other special minerals. These materials are of great importance
in bulk searches for fractional charge particles that may have been produced in
the early universe.Comment: 17 pages, 5 figures in a singl PDF file (created from WORD Doc.).
Submitted to Review of Scientific Instrument
Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
We present five new satellites of the Milky Way discovered in Sloan Digital
Sky Survey (SDSS) imaging data, four of which were followed-up with either the
Subaru or the Isaac Newton Telescopes. They include four probable new dwarf
galaxies -- one each in the constellations of Coma Berenices, Canes Venatici,
Leo and Hercules -- together with one unusually extended globular cluster,
Segue 1. We provide distances, absolute magnitudes, half-light radii and
color-magnitude diagrams for all five satellites. The morphological features of
the color-magnitude diagrams are generally well described by the ridge line of
the old, metal-poor globular cluster M92. In the last two years, a total of ten
new Milky Way satellites with effective surface brightness mu_v >~ 28 mag/sq.
arcsec have been discovered in SDSS data. They are less luminous, more
irregular and appear to be more metal-poor than the previously-known nine Milky
Way dwarf spheroidals. The relationship between these objects and other
populations is discussed. We note that there is a paucity of objects with
half-light radii between ~40 pc and ~ 100 pc. We conjecture that this may
represent the division between star clusters and dwarf galaxies.Comment: 10 pages, 8 figures, submitted to the Astrophysical Journa
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