32,506 research outputs found
Zero gravity liquid mixer
An apparatus for mixing liquids under conditions of zero gravity is disclosed. The apparatus is comprised of a closed reservoir for the liquids, with a means for maintaining a positive pressure on the liquids in the reservoir. A valved liquid supply line is connected to the reservoir for supplying the reservoir with the liquids to be mixed in the reservoir. The portion of the reservoir containing the liquids to be mixed is in communication with a pump which alternately causes a portion of the liquids to flow out of the pump and into the reservoir to mix the liquids. The fluids in the reservoir are in communication through a conduit with the pump which alternately causes a portion of the fluids to flow out of the pump and into the sphere. The conduit connecting the pump and sphere may contain a nozzle or other jet-forming structure such as a venturi for further mixing the fluids
A Note on Adult Overwintering of Dasymutilla Nigripes in Michigan (Hymenoptera: Mutillidae)
Excerpt: Although Dasymutilla nigripes (Fabricius) is one of the more common Michigan velvet ant species, little is known about its life cycle. In his summary of mutillid life cycles, Michel (1928) indicated that mutillids of northern latitudes probably overwinter in the prepupal stage within the subterranean cells of their hymenopterous hosts. Bohart and McSwain (1939) cited prepupal overwintering as normal for Dasymutilla sackenii (Cresson) in California. However, Potts and Smith (1944), also working in California, collected overwintering adult female Dasymutilla aureola pacifica (Cresson)
Polynomial treewidth forces a large grid-like-minor
Robertson and Seymour proved that every graph with sufficiently large
treewidth contains a large grid minor. However, the best known bound on the
treewidth that forces an grid minor is exponential in .
It is unknown whether polynomial treewidth suffices. We prove a result in this
direction. A \emph{grid-like-minor of order} in a graph is a set of
paths in whose intersection graph is bipartite and contains a
-minor. For example, the rows and columns of the
grid are a grid-like-minor of order . We prove that polynomial
treewidth forces a large grid-like-minor. In particular, every graph with
treewidth at least has a grid-like-minor of order
. As an application of this result, we prove that the cartesian product
contains a -minor whenever has treewidth at least
.Comment: v2: The bound in the main result has been improved by using the
Lovasz Local Lemma. v3: minor improvements, v4: final section rewritte
Air removal device
The disclosure concerns a device suitable for removing air from water under both zero and one 'g' gravity conditions. The device is comprised of a pair of spaced membranes on being hydrophobic and the other being hydrophilic. The air-water mixture is introduced into the space therebetween, and the selective action of the membranes yields removal of the air from the water
A Census of Object Types and Redshift Estimates in the SDSS Photometric Catalog from a Trained Decision-Tree Classifier
We have applied ClassX, an oblique decision tree classifier optimized for
astronomical analysis, to the homogeneous multicolor imaging data base of the
Sloan Digital Sky Survey (SDSS), training the software on subsets of SDSS
objects whose nature is precisely known via spectroscopy. We find that the
software, using photometric data only, correctly classifies a very large
fraction of the objects with existing SDSS spectra, both stellar and
extragalactic. ClassX also accurately predicts the redshifts of both normal and
active galaxies in SDSS. To illustrate ClassX applications in SDSS research, we
(a) derive the object content of the SDSS DR2 photometric catalog and (b)
provide a sample catalog of resolved SDSS objects that contains a large number
of candidate AGN galaxies, 27,000, along with 63,000 candidate normal galaxies
at magnitudes substantially fainter than typical magnitudes of SDSS
spectroscopic objects. The surface density of AGN selected by ClassX to i~19 is
in agreement with that quoted by SDSS. When ClassX is applied to the
photometric data fainter than the SDSS spectroscopic limit, the inferred
surface density of AGN rises sharply, as expected. The ability of the
classifier to accurately constrain the redshifts of huge numbers (ultimately ~
10^7) of active galaxies in the photometric data base promises new insights
into fundamental issues of AGN research, such as the evolution of the AGN
luminosity function with cosmic time, the starburst--AGN connection, and
AGN--galactic morphology relationships.Comment: Accepted for publication in The Astronomical Journal, Vol. 130, 2005;
33 pages, 10 figures, 5 tables, AASTeX v5.0. Table 5 will be electronic in
the published journal, but available now at
http://www-int.stsci.edu/~margon/table5.ascii and
http://www-int.stsci.edu/~margon/table5.ascii.g
Heat transfer device and method of making the same
Gas derived graphite fibers are generated by the decomposition of an organic gas. These fibers when joined with a suitable binder are used to make a high thermal conductivity composite material. The fibers may be intercalated. The intercalate can be halogen or halide salt, alkaline metal, or any other species which contributes to the electrical conductivity improvement of the graphite fiber. The heat transfer device may also be made of intercalated highly oriented pyrolytic graphite and machined, rather than made of fibers
MOVING FROM UNIFORM TO VARIABLE FERTILIZER RATES ON IOWA CORN: EFFECTS ON RATES AND RETURNS
This study develops a model based on the yield potential of various soil types in 12 Iowa counties to estimate the potential value of switching from uniform to variable fertilizer rates. Results indicate modest increases in the gross returns over fertilizer costs, ranging from 1.52 per acre. The net profitability of variable-rate technology (VRT) is sensitive to the per acre costs of moving to a VRT program. Under the assumptions of the model, applying variable rates would increase yield by 0.05 to 0.5 bushels per acre, and would reduce fertilizer costs by 6.83 per acre.Crop Production/Industries,
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