31,267 research outputs found
Kaon Phase Space Density in Heavy Ion Collisions
The first measurement of kaon phase space densities are presented as a
function of transverse mass, center of mass energy and the number of
participants. The kaon phase space density increases with the number of
participants from e+e- to Pb+Pb collisions. However the ratio of the kaon and
pion phase space densities at low transverse momentum is independent of the
number of participants for sqrt{s}=17GeV/nucleon
This paper is dedicated to Francis Riccardelli, engineer for the Port
Authority, who died on September 11th 2001 while evacuating others.Comment: 4 pages, 2 eps figures, proceedings of Strange Quarks in Matter,
Frankfurt 2001, submitted to J. Phys. G In response to referees comments I
derived an expresion for the ratio of kaon and pion phase space densites and
made several clarifications in the tex
Thermal and structural modeling of superinsulation
Model permits direct physical measurement of the thermal response of critical components of space telescopes, thus providing flexibility for systems studies and design changes
Theoretical Analysis of STM Experiments at Rutile TiO_2 Surfaces
A first-principles atomic orbital-based electronic structure method is used
to investigate the low index surfaces of rutile Titanium Dioxide. The method is
relatively cheap in computational terms, making it attractive for the study of
oxide surfaces, many of which undergo large reconstructions, and may be
governed by the presence of Oxygen vacancy defects. Calculated surface charge
densities are presented for low-index surfaces of TiO, and the relation of
these results to experimental STM images is discussed. Atomic resolution images
at these surfaces tend to be produced at positive bias, probing states which
largely consist of unoccupied Ti 3 bands, with a small contribution from O
2. These experiments are particularly interesting since the O atoms tend to
sit up to 1 angstrom above the Ti atoms, so providing a play-off between
electronic and geometric structure in image formation.Comment: 9 pages, Revtex, 3 postscript figures, accepted by Surf. Scienc
Chemistry in Bioinformatics
A preprint of an invited submission to BioMedCentral Bioinformatics. This short manuscript is an overview or the current problems and opportunities in publishing chemical information. Full details of technology are given in the sibling manuscript http://www.dspace.cam.ac.uk/handle/1810/34579
The manuscript is the authors' preprint although it has been automatically transformed into this archived PDF by the submission system. The authors are not responsible for the formattingChemical information is now seen as critical for most areas
of life sciences. But unlike Bioinformatics, where data is
Openly available and freely re−usable, most chemical
information is closed and cannot be re−distributed without
permission. This has led to a failure to adopt modern
informatics and software techniques and therefore paucity of
chemistry in bioinformatics. New technology, however, offers
the hope of making chemical data (compounds and properties)
Free during the authoring process. We argue that the technology
is already available; we require a collective agreement to
enhance publication protocols
Thermal and structural modeling of a large aperture space telescope Technical summary report, 22 Jun. - 22 Sep. 1968
Thermal and structural modeling for large aperture space telescop
A survey of low-velocity collisional features in Saturn's F ring
Small (~50km scale), irregular features seen in Cassini images to be
emanating from Saturn's F ring have been termed mini-jets by Attree et al.
(2012). One particular mini-jet was tracked over half an orbital period,
revealing its evolution with time and suggesting a collision with a local
moonlet as its origin. In addition to these data we present here a much more
detailed analysis of the full catalogue of over 800 F ring mini-jets, examining
their distribution, morphology and lifetimes in order to place constraints on
the underlying moonlet population. We find mini-jets randomly located in
longitude around the ring, with little correlation to the moon Prometheus, and
randomly distributed in time, over the full Cassini tour to date. They have a
tendency to cluster together, forming complicated `multiple' structures, and
have typical lifetimes of ~1d. Repeated observations of some features show
significant evolution, including the creation of new mini-jets, implying
repeated collisions by the same object. This suggests a population of <~1km
radius objects with some internal strength and orbits spread over 100km in
semi-major axis relative to the F ring but with the majority within 20km. These
objects likely formed in the ring under, and were subsequently scattered onto
differing orbits by, the perturbing action of Prometheus. This reinforces the
idea of the F ring as a region with a complex balance between collisions,
disruption and accretion.Comment: 21 pages, 12 figures. Accepted for publication in Icarus.
Supplementary information available at
http://www.maths.qmul.ac.uk/~attree/mini-jets
Anomalous reaction-transport processes: the dynamics beyond the Mass Action Law
In this paper we reconsider the Mass Action Law (MAL) for the anomalous
reversible reaction with diffusion. We provide a
mesoscopic description of this reaction when the transitions between two states
and are governed by anomalous (heavy-tailed) waiting-time
distributions. We derive the set of mesoscopic integro-differential equations
for the mean densities of reacting and diffusing particles in both states. We
show that the effective reaction rate memory kernels in these equations and the
uniform asymptotic states depend on transport characteristics such as jumping
rates. This is in contradiction with the classical picture of MAL. We find that
transport can even induce an extinction of the particles such that the density
of particles or tends asymptotically to zero. We verify analytical
results by Monte Carlo simulations and show that the mesoscopic densities
exhibit a transient growth before decay.Comment: 4 pages, 3 figure
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