Universality and quantum effects in one-component critical fluids

Non-universal scale transformations of the physical fields are extended to pure quantum fluids and used to calculate susceptibility, specific heat and the order parameter along the critical isochore of He3 near its liquid-vapor critical point. Within the so-called preasymptotic domain, where the Wegner expansion restricted to the first term of confluent corrections to scaling is expected valid, the results show agreement with the experimental measurements and recent predictions, either based on the minimal-substraction renormalization and the massive renormalization schemes within the $\Phi\_{d=3}^{4}(n=1)$-model, or based on the crossover parametric equation of state for Ising-like systems

Granular Media under Vibration in Zero Gravity: Transition from Rattling to Granular Gas

We report on different experimental behaviours of granular dissipative matter excited by vibration as studied during the 43rd ESA campaign of Airbus A300-0g from CNES. The effect of g-jitter is quantified through the generation of a rattle effect. The French-European team's electromagnetic set-up is used, with 20Hz cam recording and high speed camera for a short duration (1s) during each parabola.Comment: Poudres et Grains 201

Master crossover functions for the one-component fluid "subclass"

Introducing three well-defined dimensionless numbers, we establish the link between the scale dilatation method able to estimate master (i.e. unique) singular behaviors of the one-component fluid "subclass" and the universal crossover functions recently estimated [Garrabos and Bervillier, Phys. Rev. E 74, 021113 (2006)] from the bounded results of the massive renormalization scheme applied to the..

Master crossover behavior of parachor correlations for one-component fluids

The master asymptotic behavior of the usual parachor correlations, expressing surface tension $\sigma$ as a power law of the density difference $\rho_{L}-\rho_{V}$ between coexisting liquid and vapor, is analyzed for a series of pure compounds close to their liquid-vapor critical point, using only four critical parameters $(\beta_{c})^{-1}$, $\alpha_{c}$, $Z_{c}$ and $Y_{c}$, for each fluid. ... The main consequences of these theoretical estimations are discussed in the light of engineering applications and process simulations where parachor correlations constitute one of the most practical method for estimating surface tension from density and capillary rise measurements

Master singular behavior for the Sugden factor of the one-component fluids near their gas-liquid critical point

We present the master (i.e. unique) behavior of the squared capillary length - so called the Sudgen factor-, as a function of the temperature-like field along the critical isochore, asymptotically close to the gas-liquid critical point of twenty (one component) fluids. This master behavior is obtained using the scale dilatation of the relevant physical fields of the one-component fluids. The scale dilatation introduces the fluid-dependent scale factors in a manner analog with the linear relations between physical fields and scaling fields needed by the renormalization theory applied to the Ising-like universality class. The master behavior for the Sudgen factor satisfies hyperscaling and can be asymptotically fitted by the leading terms of the theoretical crossover functions for the correlation length and the susceptibility in the homogeneous domain recently obtained from massive renormalization in field theory. In the absence of corresponding estimation of the theoretical crossover functions for the interfacial tension, we define the range of the temperature-like field where the master leading power law can be practically used to predict the singular behavior of the Sudgen factor in conformity with the theoretical description provided by the massive renormalization scheme within the extended asymptotic domain of the one-component fluid "subclass"

Collision statistics in a dilute granular gas fluidized by vibrations in low gravity

We report an experimental study of a dilute "gas" of inelastically colliding particles excited by vibrations in low gravity. We show that recording the collision frequency together with the impulses on a wall of the container gives access to several quantities of interest. We observe that the mean collision frequency does not scale linearly with the number N of particles in the container. This is due to the dissipative nature of the collisions and is also directly related to the non extensive behaviour of the kinetic energy (the granular temperature is not intensive).Comment: to be pubished in Europhysics Letters (May/June 2006

Spinodal Decomposition in Binary Gases

We carried out three-dimensional simulations, with about 1.4 million particles, of phase segregation in a low density binary fluid mixture, described mesoscopically by energy and momentum conserving Boltzmann-Vlasov equations. Using a combination of Direct Simulation Monte Carlo(DSMC) for the short range collisions and a version of Particle-In-Cell(PIC) evolution for the smooth long range interaction, we found dynamical scaling after the ratio of the interface thickness(whose shape is described approximately by a hyperbolic tangent profile) to the domain size is less than ~0.1. The scaling length R(t) grows at late times like t^alpha, with alpha=1 for critical quenches and alpha=1/3 for off-critical ones. We also measured the variation of temperature, total particle density and hydrodynamic velocity during the segregation process.Comment: 11 pages, Revtex, 4 Postscript figures, submitted to PR

Scaling behaviour of the fluid subclass near the liquid-gas critical point

Non-universal scale transformations are proposed for the two relevant physical distances to the liquid-gas critical point along the critical isochore and critical isotherm. These scale transformations allow us to observe an identical singular behaviour for all pure fluids near their liquid-gas critical point.Nous proposons des transformations d'échelle non universelles pour les deux variables physiques mesurant les distances au point critique liquide-vapeur d'un fluide pur le long de son isochore critique et de son isotherme critique. Après avoir effectué ces transformations d'échelle, nous observons des comportements singuliers uniques pour tous les fluides purs proches de leur point critique liquide-vapeur

Facteurs d'échelle phénoménologiques pour la transition critique liquide-gaz des fluides purs

We discuss a phenomenological method which allows to determine the singular asymptotic behaviours for a pure fluid at equilibrium, when the liquid-gas critical point and the tangent plane to the characteristic surface of this point are localized experimentally, in the pressure, density and temperature coordinates.Nous discutons une méthode phénologique permettant de déterminer les comportements singuliers asymptotiques d'un fluide pur à l'équilibre, lorsque son point critique liquide-vapeur et le plan tangent à la surface caractéristique en ce point sont localisés expérimentalement dans l'espace des phases pression, densité et température