1,046,688 research outputs found
Hydraulic characteristics of flow through miniature slits
Hydraulic characteristics of micro-orifices arrayed in close proximity across the face of a liquid fuel injector are studied. Effects of geometry and flow variables on discharge coefficients and flow regimes are determined, as well as visible characteristics of the emerging liquid streams
Double window viewing chamber assembly
A viewing chamber which permits observation of a sample retained therein includes a pair of double window assemblies mounted in opposed openings in the walls thereof so that a light beam can directly enter and exit from the chamber. A flexible mounting arrangement for the outer windows of the window assemblies enables the windows to be brought into proper alignment. An electrical heating arrangement prevents fogging of the outer windows whereas desiccated air in the volume between the outer and inner windows prevents fogging of the latter
High current electrical lead
An electrical lead has insulators imbedded in an inner conductor rod to form an annulus between the rod and a surrounding outer sheath. This annular space is filled with gas which conducts heat and prevents electrical leakage
The Kinematic and Spatial Deployment of Compact, Isolated High-Velocity Clouds
We have identified a class of high-velocity clouds which are compact and
apparently isolated. The clouds are compact in that they have angular sizes
less than 2 degrees FWHM. They are isolated in that they are separated from
neighboring emission by expanses where no emission is seen to the detection
limit of the available data. Candidates for inclusion in this class were
extracted from the Leiden/Dwingeloo HI survey of Hartmann & Burton and from the
Wakker & van Woerden catalogue of high-velocity clouds. The candidates were
subject to independent confirmation using either the 25-meter telescope in
Dwingeloo or the 140-foot telescope in Green Bank. We argue that the resulting
list, even if incomplete, is sufficiently representative of the ensemble of
compact, isolated HVCs - CHVCs - that the characteristics of their disposition
on the sky, and of their kinematics, are revealing of some physical aspects of
the class. The CHVCs are in fact distributed quite uniformly across the sky. A
global search for the reference frame which minimizes the velocity dispersion
of the ensemble returns the Local Group Standard of Rest with high confidence.
The CHVCs are not stationary with respect to this reference frame but have a
mean infall velocity of 100 km/s. These properties are strongly suggestive of a
population which has as yet had little interaction with the more massive Local
Group members. At a typical distance of about 1 Mpc these objects would have
sizes of about 15 kpc and gas masses, M_HI, of a few times 10^7 M_Sun,
corresponding to those of (sub-)dwarf galaxies. (abridged)Comment: 13 page LaTeX, requires aa.cls and rotate.sty, 5 GIF figures.
Accepted for publication in A&
Solid state power mapping instrument Patent
Solid state device for mapping flux and power in nuclear reactor core
Pion Charge Exchange on Deuterium
We investigate quantum corrections to a classical intranuclear cascade
simulation of pion single charge exchange on the deuteron. In order to separate
various effects the orders of scattering need to be distinguished and, to that
end, we develop signals for each order of scattering corresponding to
quasi-free conditions. Quantum corrections are evaluated for double scattering
and are found to be large. Global agreement with the data is good.Comment: 30 pages, 12 figure
Reflections in abstract Coxeter groups
Let be a Coxeter group and a reflection. If the group of order 2
generated by is the intersection of all the maximal finite subgroups of
that contain it, then any isomorphism from to a Coxeter group must
take to a reflection in . The aim of this paper is to show how to
determine, by inspection of the Coxeter graph, the intersection of the maximal
finite sugroups containing . In particular we show that the condition above
is satisfied whenever is infinite and irreducible, and has the property
that all rank two parabolic subgroups are finite. So in this case all
isomorphisms map reflections to reflections.Comment: 25 pages, 0 figure
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