Time-reversal symmetry relation for nonequilibrium flows ruled by the fluctuating Boltzmann equation

A time-reversal symmetry relation is established for out-of-equilibrium dilute or rarefied gases described by the fluctuating Boltzmann equation. The relation is obtained from the associated coarse-grained master equation ruling the random numbers of particles in cells of given position and velocity in the single-particle phase space. The symmetry relation concerns the fluctuating particle and energy currents of the gas flowing between reservoirs or thermalizing surfaces at given particle densities or temperatures.Comment: The result of this paper has been presented at the conference "Boltzmann equation: mathematics, modeling and simulations" in memory of Carlo Cercignani at the Henri Poincar\'e Institute, Paris, February 9-11, 201

J/Psi Production in Au-Au Collisions at sqrt(s_NN) = 200 GeV at the Relativistic Heavy Ion Collider

First results on charm quarkonia production in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The yield of J/Psi's measured in the PHENIX experiment via electron-positron decay pairs at mid-rapidity for Au-Au reactions at sqrt(s_NN) = 200 GeV are analyzed as a function of collision centrality. For this analysis we have studied 49.3 million minimum bias Au-Au reactions. We present the J/Psi invariant yield dN/dy for peripheral and mid-central reactions. For the most central collisions where we observe no signal above background, we quote 90% confidence level upper limits. We compare these results with our J/Psi measurement from proton-proton reactions at the same energy. We find that our measurements are not consistent with models that predict strong enhancement relative to binary collision scaling.Comment: 325 authors, 11 pages text, 6 figures, 4 tables, RevTeX 4. Accepted for publication as a regular article in Physical Review C. This version has minor changes to respond to referee suggestions. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/papers.htm

Application of a periodic table for the genetic code to influenza A/H3N2 virus

If biologists can utilize a table to have access to biological phenomena in the manner analogous to the periodic table for chemical elements, they may get hold of a directing post in life science. Currently the mutational rule of influenza viruses have remained perplexed and to reveal it should be now desired when avian influenza virus has just then threatened human beings. Here I examine the applicability of a novel periodic table for the genetic code to influenza A/H3N2 virus, while presenting two rules regarding single point mutations of its virus hemagglutinin gene. One rule is that non-synonymous single point mutations are intimately associated with the first or second base replacements between four groups (5, 6, 9, and 10) in the periodic table. Another rule is that there is a new index (inversion number) conserving in mutation. This paper will take the first step to such contribution of mutational reactions

Low-energy ion beamline scattering apparatus for surface science investigations

We report on the design, construction, and performance of a high current (monolayers/s), mass-filtered ion beamline system for surface scattering studies using inert and reactive species at collision energies below 1500 eV. The system combines a high-density inductively coupled plasma ion source, high-voltage floating beam transport line with magnet mass-filter and neutral stripping, decelerator, and broad based detection capabilities (ions and neutrals in both mass and energy) for products leaving the target surface. The entire system was designed from the ground up to be a robust platform to study ion-surface interactions from a more global perspective, i.e., high fluxes (>100 µA/cm2) of a single ion species at low, tunable energy (50–1400±5 eV full width half maximum) can be delivered to a grounded target under ultrahigh vacuum conditions. The high current at low energy problem is solved using an accel-decel transport scheme where ions are created at the desired collision energy in the plasma source, extracted and accelerated to high transport energy (20 keV to fight space charge repulsion), and then decelerated back down to their original creation potential right before impacting the grounded target. Scattered species and those originating from the surface are directly analyzed in energy and mass using a triply pumped, hybrid detector composed of an electron impact ionizer, hemispherical electrostatic sector, and rf/dc quadrupole in series. With such a system, the collision kinematics, charge exchange, and chemistry occurring on the target surface can be separated by fully analyzing the scattered product flux. Key design aspects of the plasma source, beamline, and detection system are emphasized here to highlight how to work around physical limitations associated with high beam flux at low energy, pumping requirements, beam focusing, and scattered product analysis. Operational details of the beamline are discussed from the perspective of available beam current, mass resolution, projectile energy spread, and energy tunability. As well, performance of the overall system is demonstrated through three proof-of-concept examples: (1) elastic binary collisions at low energy, (2) core-level charge exchange reactions involving 20Ne+ with Mg/Al/Si/P targets, and (3) reactive scattering of CF2+/CF3+ off Si. These studies clearly demonstrate why low, tunable incident energy, as well as mass and energy filtering of products leaving the target surface is advantageous and often essential for studies of inelastic energy losses, hard-collision charge exchange, and chemical reactions that occur during ion-surface scattering