17,685 research outputs found
A semi-implicit numerical method for treating the time transient gas lubrication equation
Numerical method for treating time transient gas lubrication equatio
Application of remote sensing for fishery resource assessment and monitoring
There are no author-identified significant results in this report
Nonequilibrium electron rings for synchrotron radiation production
Electron storage rings used for the production of synchrotron radiation (SR)
have an output photon brightness that is limited by the equilibrium beam
emittance. By using interleaved injection and ejection of bunches from a source
with repetition rate greater than 1 kHz, we show that it is practicable to
overcome this limit in rings of energy ~1 GeV. Sufficiently short kicker pulse
lengths enable effective currents of many milliamperes, which can deliver a
significant flux of diffraction-limited soft X-ray photons. Thus, either
existing SR facilities may be adapted for non-equilibrium operation, or the
technique applied to construct SR rings smaller than their storage ring
equivalent.Comment: 5 pages, 2 figures; accepted for publication in Physical Review
Letter
Application of remote sensing for fishery resource assessment and monitoring. Skylab oceanic gamefish project
There are no author-identified significant results in this report
Evolution of Ohmically Heated Hot Jupiters
We present calculations of thermal evolution of Hot Jupiters with various
masses and effective temperatures under Ohmic dissipation. The resulting
evolutionary sequences show a clear tendency towards inflated radii for
effective temperatures that give rise to significant ionization of alkali
metals in the atmosphere, compatible with the trend of the data. The degree of
inflation shows that Ohmic dissipation, along with the likely variability in
heavy element content can account for all of the currently detected radius
anomalies. Furthermore, we find that in absence of a massive core, low-mass hot
Jupiters can over-flow their Roche-lobes and evaporate on Gyr time-scales,
possibly leaving behind small rocky cores.Comment: Accepted to The Astrophysical Journal (2011) 735-2, 9 pages, 8
figures, updated figures 2-
Pathologies in the sticky limit of hard-sphere-Yukawa models for colloidal fluids. A possible correction
A known `sticky-hard-sphere' model, defined starting from a
hard-sphere-Yukawa potential and taking the limit of infinite amplitude and
vanishing range with their product remaining constant, is shown to be
ill-defined. This is because its Hamiltonian (which we call SHS2) leads to an
{\it exact}second virial coefficient which {\it diverges}, unlike that of
Baxter's original model (SHS1). This deficiency has never been observed so far,
since the linearization implicit in the `mean spherical approximation' (MSA),
within which the model is analytically solvable, partly {\it masks} such a
pathology. To overcome this drawback and retain some useful features of SHS2,
we propose both a new model (SHS3) and a new closure (`modified MSA'), whose
combination yields an analytic solution formally identical with the SHS2-MSA
one. This mapping allows to recover many results derived from SHS2, after a
re-interpretation within a correct framework. Possible developments are finally
indicated.Comment: 21 pages, 1 figure, accepted in Molecular Physics (2003
Chemokine-induced secretion of gelatinase B in primary human monocytes
Chemokines help control normal leukocyte trafficking as well as their infiltration into tissues during acute and chronic inflammation. Matrix metalloproteinases (MMPs) help support the extravasation and infiltration of leukocytes through limited proteolysis of basement membranes and matrix material. The effect of the chemokines RANTES/CCL5, MCP-1/CCL and SDF-1 /CXCL12 on secretion of the matrix metalloproteinase B and its endogenous inhibitor TIMP-1 was studied. RANTES/CCL5 and SDF-1/CXCL12 were found to induce MMP-9 secretion in primary human monocytes while TIMP-1 secretion was not affected. RANTES/CCL5 effects were mediated through CCR1 because the CCR1 antagonist BX471 was found to effectively block RANTES/CCL5-induced MMP-9 secretion
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