43,568 research outputs found
Perturbatively improving renormalization constants
Renormalization factors relate the observables obtained on the lattice to
their measured counterparts in the continuum in a suitable renormalization
scheme. They have to be computed very precisely which requires a careful
treatment of lattice artifacts. In this work we present a method to suppress
these artifacts by subtracting one-loop contributions proportional to the
square of the lattice spacing calculated in lattice perturbation theory.Comment: 7 pages, 2 figures, LATTICE 201
Entropy, non-ergodicity and non-Gaussian behaviour in ballistic transport
Ballistic transportation introduces new challenges in the thermodynamic
properties of a gas of particles. For example, violation of mixing, ergodicity
and of the fluctuation-dissipation theorem may occur, since all these processes
are connected. In this work, we obtain results for all ranges of diffusion,
i.e., both for subdiffusion and superdiffusion, where the bath is such that it
gives origin to a colored noise. In this way we obtain the skewness and the
non-Gaussian factor for the probability distribution function of the dynamical
variable. We put particular emphasis on ballistic diffusion, and we demonstrate
that in this case, although the second law of thermodynamics is preserved, the
entropy does not reach a maximum and a non-Gaussian behavior occurs. This
implies the non-applicability of the central limit theorem.Comment: 9 pages, 2 figure
Confirming EIS Clusters. Optical and Infrared Imaging
Clusters of galaxies are important targets in observationally cosmology, as
they can be used both to study the evolution of the galaxies themselves and to
constrain cosmological parameters. Here we report on the first results of a
major effort to build up a sample of distant galaxy clusters to form the basis
for further studies within those fields. We search for simultaneous
overdensities in color and space to obtain supporting evidence for the reality
of the clusters. We find a confirmation rate for EIS clusters of 66%,
suggesting that a total of about 80 clusters with z>=0.6 are within reach using
the EIS cluster candidates.Comment: 4 pages, 2 figures, to appear in the proceedings of the IGRAP
International Conference 1999 on 'Clustering at high Redshift
Tuned liquid dampers simulation for earthquake response control of buildings
This paper is focused on the study of an earthquake protection system, the Tuned Liquid Damper (TLD), which
can, if adequately designed, reduce earthquake demands on buildings. This positive effect is accomplished taking
into account the oscillation of the free surface of a fluid inside a tank (sloshing). The behaviour of an isolated
Tuned Liquid Damper, subjected to a sinusoidal excitation at its base, with different displacement amplitudes,
was studied by finite element analysis. The efficiency of the TLD in improving the seismic response of an existing building, representative of modern architecture buildings in southern European countries was also evaluated based on linear dynamic analyses
VLT and NTT Observations of Two EIS Cluster Candidates. Detection of the Early-Type Galaxies Sequence at z~1
Optical data from the ESO VLT-UT1 Science Verification observations are
combined with near-infrared data from SOFI at the NTT to obtain
optical-infrared color-magnitude diagrams for the objects in the fields of two
EIS cluster candidates. In both cases, evidence is found for a well-defined
sequence of red galaxies that appear to be significantly more clustered than
the background population. These results suggest that the two systems are real
physical associations. The (R-Ks), (I-Ks) and (J-Ks) colors of the red
sequences are used, in conjunction with similar data for spectroscopically
confirmed clusters, to obtain redshift estimates of z ~ 0.9 and z ~ 1.0 for
these two systems. These results make these EIS cluster candidates prime
targets for follow-up spectroscopic observations to confirm their reality and
to measure more accurately their redshift.Comment: 6 pages, 5 figures, to appear in Astronomy & Astrophysics (Special
Letters Edition on "First Science with the VLT"
Isolamento de proteĂnas Cyt de Bacillus thuringiensis subsp. israelensis por gradiente de sacarose.
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