1,539 research outputs found
Centrality dependence of elliptic flow and QGP viscosity
In the Israel-Stewart's theory of second order hydrodynamics, we have
analysed the recent PHENIX data on charged particles elliptic flow in Au+Au
collisions.
PHENIX data demand more viscous fluid in peripheral collisions than in
central collisions. Over a broad range of collision centrality (0-10%- 50-60%),
viscosity to entropy ratio () varies between 0-0.17.Comment: Final version to be publiashed in J. Phys. G. 8 pages, 6 figures and
3 table
Equation of State and Collective Dynamics
This talk summarizes the present status of a program to quantitatively relate
data from the Relativistic Heavy Ion Collider (RHIC) on collective expansion
flow to the Equation of State (EOS) of hot and dense strongly interacting
matter, including the quark-gluon plasma and the quark-hadron phase transition.
The limits reached with the present state of the art and the next steps
required to make further progress will both be discussed.Comment: 8 pages, 6 two-part figures. Invited talk given at the 5th
International Conference on the Physics and Astrophysics of Quark-Gluon
Plasma (ICPAQGP 2005), Kolkata (India), Feb 8-12, 2005. Proceedings to be
published in Journal of Physics: Conference Series (Jan-E Alam et al., eds.
Nuclear Segmentation, Condensation and Bilateral Symmetry in Polymorphonuclear Leukocytes Reflect Genomic Order and Favor Immunologic Function
Segmentation, condensation and bilateral symmetry of the nuclei ofpolymorphonuclear leukocytes seem related to their function.Segmentation of the nuclei into two or more lobes and their condensationfacilitate their passage (diapedesis) through the endothelial layer ofblood vessels to the extravasal space and subsequent locomotion throughthe interstitial compartment of different tissues. Bilateral symmetry ofthese nuclei along with their association to the cytoskeletal fiberscontribute to their efficiency in locomotion by alignment of the axis ofnuclear symmetry to the axis of cellular polarity, which orients towardsthe direction of locomotion in response to cytokines and other stimuli.Observations of the cytogenetic facets of intranuclear order supportthese assumptions
Direct experimental observation of binary agglomerates in complex plasmas
A defocusing imaging technique has been used as a diagnostic to identify
binary agglomerates (dimers) in complex plasmas. Quasi-two-dimensional plasma
crystal consisting of monodisperse spheres and binary agglomerates has been
created where the agglomerated particles levitate just below the spherical
particles without forming vertical pairs. Unlike spherical particles, the
defocused images of binary agglomerates show distinct, stationary/periodically
rotating interference fringe patterns. The results can be of fundamental
importance for future experiments on complex plasmas
Dissipative hydrodynamics and heavy ion collisions
Space-time evolution and subsequent particle production from minimally
viscous (=0.08) QGP fluid is studied using the 2nd order
Israel-Stewart's theory of dissipative relativistic fluid. Compared to ideal
fluid, energy density or temperature evolves slowly in viscous dynamics.
Particle yield at high is increased. Elliptic flow on the other hand
decreases in viscous dynamics. Minimally viscous QGP fluid found to be
consistent with a large number of experimental data.Comment: 8 pages, 13 figures. Revised version of the invited talk at the 20th
International conference on Ultra-Relativistic Nucleus Nucleus collisions
(Quark Matter 2008), Feb. 4-10, 2008, Jaipur, Indi
Generalization of escape rate from a metastable state driven by external cross-correlated noise processes
We propose generalization of escape rate from a metastable state for
externally driven correlated noise processes in one dimension. In addition to
the internal non-Markovian thermal fluctuations, the external correlated noise
processes we consider are Gaussian, stationary in nature and are of
Ornstein-Uhlenbeck type. Based on a Fokker-Planck description of the effective
noise processes with finite memory we derive the generalized escape rate from a
metastable state in the moderate to large damping limit and investigate the
effect of degree of correlation on the resulting rate. Comparison of the
theoretical expression with numerical simulation gives a satisfactory agreement
and shows that by increasing the degree of external noise correlation one can
enhance the escape rate through the dressed effective noise strength.Comment: 9 pages, 1 figur
Nuclear Segmentation, Condensation and Bilateral Symmetry in Polymorphonuclear Leukocytes Reflect Genomic Order and Favor Immunologic Function
Segmentation, condensation and bilateral symmetry of the nuclei ofpolymorphonuclear leukocytes seem related to their function.Segmentation of the nuclei into two or more lobes and their condensationfacilitate their passage (diapedesis) through the endothelial layer ofblood vessels to the extravasal space and subsequent locomotion throughthe interstitial compartment of different tissues. Bilateral symmetry ofthese nuclei along with their association to the cytoskeletal fiberscontribute to their efficiency in locomotion by alignment of the axis ofnuclear symmetry to the axis of cellular polarity, which orients towardsthe direction of locomotion in response to cytokines and other stimuli.Observations of the cytogenetic facets of intranuclear order supportthese assumptions
- …