35,242 research outputs found
A critical survey of upper-atmosphere density measurements by means of ionization gauges
Critical survey of upper atmosphere density measurements by ionization gauge
A process yields large quantities of pure ribosome subunits
Development of process for in-vitro protein synthesis from living cells followed by dissociation of ribosomes into subunits is discussed. Process depends on dialysis or use of chelating agents. Operation of process and advantages over previous methods are outlined
Behavior of the sonic boom shock wave near the sonic cutoff altitude
Behavior of sonic boom shock wave near sonic cutoff altitud
The detection of markovian sequences of signals technical report no. 23
Detection of pure tone embedded in noise - Markov chains of signal
Media Coverage of EPA\u27s Draft Dioxin Reassessment Report
Using content analysis, the authors examine the utility of news media in democratic decision making
The Narrow-band Ultraviolet Imaging Experiment for Wide-field Surveys (NUVIEWS)-I: Dust scattered continuum
We report on the first results of the Narrow-band Ultraviolet Imaging
Experiment for Wide-field Surveys (NUVIEWS), a sounding rocket experiment
designed to map the far-ultraviolet background in four narrow bands. This is
the first imaging measurement of the UV background to cover a substantial
fraction of the sky. The narrow band responses (145, 155, 161, and 174 nm, 7-10
nm wide) allow us to isolate background contributions from dust-scattered
continuum, H2 fluorescence, and CIV 155 nm emission. In our first flight, we
mapped one quarter of the sky with 5-10 arcminute imaging resolution. In this
paper, we model the dominant contribution of the background, dust-scattered
continuum. Our data base consists of a map of over 10,000 sq. degrees with 468
independent measurements in 6.25 by 6.25 sq. degree bins. Stars and
instrumental stellar halos are removed from the data. We present a map of the
continuum background obtained in the 174 nm telescope. We use a model that
follows Witt, Friedman, and Sasseen (1997: WFS) to account for the
inhomogeneous radiation field and multiple scattering effects in clouds. We
find that the dust in the diffuse interstellar medium displays a moderate
albedo (a=0.55+/-0.1) and highly forward scattering phase function parameter
(g=0.75+/-0.1) over a large fraction of the sky, similar to dust in star
forming regions. We also have discovered a significant variance from the model.Comment: 16 pages, 3 ps figures, submitted to Astrophysical Journal Letter
Experience in feeding coal into a liquefaction process development unit
A system for preparing coal slurry and feeding it into a high pressure liquefaction plant is described. The system was developed to provide supporting research and development for the Bureau of Mines coal liquefaction pilot plant. Operating experiences are included
A review of congenital heart block
Congenital heart block is a rare disorder. It has an incidence of about 1 in 22,000 live
births. It may be associated with high mortality and morbidity. This should generate a
high index of suspicion for early diagnosis and aggressive therapy when appropriate.
The congenital heart block associated with neonatal lupus is considered a form of
passively acquired autoimmune disease in which maternal autoantibodies to the
intracellular ribonucleoproteins Ro (SS-A) and La (SS-B), cross the placenta and
injure the previously normal fetal heart. Women with serum titers of anti-Ro antibody
carry a 3% risk of having a child with neonatal lupus syndrome. Recurrence rates are
about 18%. We believe that serial echocardiograms should be acquired so that early
diagnosis is made and aggressive therapy administered, if signs of conduction
system disease such as PR interval prolongation by Doppler are found, so as to
optimize the outcome. Establishment of guidelines for therapy have been set
empirically, should signs of congenital heart block develop. Those patients whose
congenital heart block is associated with structural heart disease have a higher
morbidity and mortality, which is determined more by the underlying structural
congenital heart disease than it is by the need for a pacemaker per se.peer-reviewe
Extended Hodge Theory for Fibred Cusp Manifolds
For a particular class of pseudo manifolds, we show that the intersection
cohomology groups for any perversity may be naturally represented by extended
weighted harmonic forms for a complete metric on the regular stratum with
respect to some weight determined by the perversity. Extended weighted
harmonic forms are harmonic forms that are almost in the given weighted
space for the metric in question, but not quite. This result is akin to the
representation of absolute and relative cohomology groups for a manifold with
boundary by extended harmonic forms on the associated manifold with cylindrical
ends. As in that setting, in the unweighted case, the boundary values of
the extended harmonic forms define a Lagrangian splitting of the boundary space
in the long exact sequence relating upper and lower middle perversity
intersection cohomology groups.Comment: 26 page
Decay rate and other properties of the positronium negative ion
A new method for detecting the positronium minus ion is described, and the possibility of a long positronium mean free path in a solid is discussed
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