54 research outputs found
Moment inequalities and high-energy tails for the Boltzmann equations with inelastic interactions
We study the high-energy asymptotics of the steady velocity distributions for
model systems of granular media in various regimes. The main results obtained
are integral estimates of solutions of the hard-sphere Boltzmann equations,
which imply that the velocity distribution functions behave in a certain
sense as for large. The values of , which we call
{\em the orders of tails}, range from to , depending on the model of
external forcing. The method we use is based on the moment inequalities and
careful estimating of constants in the integral form of the Povzner-type
inequalities.Comment: 22 page
The McKean-Vlasov Equation in Finite Volume
We study the McKean--Vlasov equation on the finite tori of length scale
in --dimensions. We derive the necessary and sufficient conditions for the
existence of a phase transition, which are based on the criteria first
uncovered in \cite{GP} and \cite{KM}. Therein and in subsequent works, one
finds indications pointing to critical transitions at a particular model
dependent value, of the interaction parameter. We show that
the uniform density (which may be interpreted as the liquid phase) is
dynamically stable for and prove, abstractly, that a
{\it critical} transition must occur at . However for
this system we show that under generic conditions -- large, and
isotropic interactions -- the phase transition is in fact discontinuous and
occurs at some \theta\t < \theta^{\sharp}. Finally, for H--stable, bounded
interactions with discontinuous transitions we show that, with suitable
scaling, the \theta\t(L) tend to a definitive non--trivial limit as
Spectral Components of SS 433
We present results from new optical and UV spectroscopy of the unusual binary
system SS 433, and we discuss the relationship of the particular spectral
components we observe to the properties of the binary. (1) The continuum
spectrum which we associate with flux from the super-Eddington accretion disk
and the dense part of its wind. (2) H-alpha moving components which are formed
far from the binary orbital plane in the relativistic jets. (3) H-alpha and He
I "stationary" emission lines which we suggest are formed in the disk wind in a
volume larger than the dimensions of the binary. (4) A weak "stationary"
emission feature we identify as a C II 7231,7236 blend that attains maximum
radial velocity at the orbital quadrature of disk recession. (5) Absorption and
emission features from outflowing clumps in the disk wind (seen most clearly in
an episode of blue-shifted Na I emission). (6) We found no clear evidence of
the absorption line spectrum of the optical star, although we point out the
presence of He I absorption features (blended with the stationary emission)
with the expected radial velocity trend at the orbital and precessional phases
when the star might best be seen. (7) A rich interstellar absorption spectrum
of diffuse interstellar bands. The results suggest that the binary is embedded
in an expanding thick disk (detected in recent radio observations) which is fed
by the wind from the super-Eddington accretion disk.Comment: Submitted to Ap
FATTY LIVER DISEASE. MODERN PATHOGENETIC APPROACH TO THERAPY
Since 1980 when L. Ludwig et al. [1] identified changes in the liver characteristic of alcohol-induced hepatitis in persons who didn’t misuse alcohol, intense study of non-alcoholic fatty liver disease (NAFLD) started. The definition of NAFLD has two major principles: a morphological pattern in biopsy ma terial microscopy completely corresponds to changes induced by alcoholic pathology and the major etiologic factors is lacking – alcoholic at hepatotoxic dosages. Obligatory condition is to rule out viral, drug, metabolic and other reasons [2]
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