arXiv subjects

Paul V. Quinn

Publications and source records attributed to Paul V. Quinn.

6 recordsLinked to original sources

arXiv2002

Hong et al. reply to Walliser

We find it absurd that Walliser [1] essentially used the same analysis and obtained identical results as reported in [3], yet arrived at different conclusions. Namely, based on an incomplete theory and using erroneous arguments, he not only disputes the original results [2], but also claims them wrong. A more complete theory and much more detailed studies were published in [3], from which we concluded that such results support the mechanism of segregation introduced in ref. [2]. We want to make it clear that Walliser obtained partial results of ref. [3] and arrived at the opposite conclusion. In the following we discuss his comment and its relevance, but at the same time point out what went wrong with his arguments.

cond-mat.stat-mech↗

arXiv2002

Hong et al reply to Canul-Chay et al

Canul-Chay et al. [1] have conducted the segregation experiment of binary granular mixtures in a bed and subjected the bed to vibration. They report that the reverse Brazil-Nut phenomenon (RBNP) was never observed in their experiments and thus conclude that such does not exist. However, we have clearly demonstrated in [2] by Molecular Dynamics simulations that the reverse Brazil-Nut problem not only exists, but can be determined from the solid-liquid phase boundary by a scaling theory for the crossover from RBNP. Hence, instead of disputing Canul-Chay et al.'s sound experimental results [1], in this reply we want to draw the reader's attention to the experimental set up and the interpretation of the experimental results.

cond-mat.stat-mech↗

arXiv2000

The Reverse Brazil Nut Problem: Competition between Percolation and Condensation

In the Brazil nut problem (BNP), hard spheres with larger diameters rise to the top. There are various explanations (percolation, reorganization, convection), but a broad understanding or control of this effect is by no means acheived. A theory is presented for the crossover from the BNP to the reverse Brazil nut problem (RBNP) based on a competition between the percolation effect and the condensation of hard spheres. The crossover condition is determined, and the theoretical predictions are compared to Molecular Dynamics simulations in two and three dimensions.

cond-mat.mtrl-sci↗

arXiv2000

Liquid-Solid Transition of Hard Spheres Under Gravity

We investigate the liquid-solid transition of two dimensional hard spheres in the presence of gravity. We determine the transition temperature and the fraction of particles in the solid regime as a function of temperature via Even-Driven molecular dynamics simulations and compare them with the theoretical predictions. We then examine the configurational statistics of a vibrating bed from the view point of the liquid-solid transition by explicitly determining the transition temperature and the effective temperature, T, of the bed, and present a relation between T and the vibration strength.

cond-mat↗

arXiv1999

Fermi Statistics of Weakly Exicted Granular Systems in a Vibrating Bed I: Molecular Dynamics Simulations

Molecular dynamics simulations were carried out to test the thermodynamic theory of weakly excited, two-dimensional granular systems [Hayakawa and Hong, Phys. Rev. Lett. 78, 2764 (1997)], where granular materials are viewed as a collection of spinless Fermions. We first determine the global temperature T by fitting the steady state density profile to the Fermi distribution function, and then measure the center of mass, , and its fluctuations, <(Δz(T))^2> as a function of T. We find a fairly good agreement between theory and simulations, in particular, in the estimation of the temperature and the scaling behavior of and <(Δz(T))^2>.

cond-mat.stat-mech↗

arXiv1999

Fermi Statistics of Weakly Excited Granular Materials in a Vibrating Bed II: One Dimensional Experiment

A one dimensional experiment in granular dynamics is carried out to test the thermodynamic theory of weakly excited granular systems [Hayakawa and Hong, Phys. Rev. Lett. {\bf 78}, 2764(1997)] where granular particles are treated as spinless Fermions. The density profile is measured and then fit to the Fermi distribution function, from which the global temperature of the system, T, is determined. Then the center of mass, , and its fluctuations, <(Δz(T))^2>, are measured and plotted as functions of T. The Fermi function fits the density profile fairly well, with the value of T being fairly close to the predicted value. The scaling behavior of and <(Δz(T))^2> is in excellent agreement with the theory.

cond-mat.mtrl-sci↗