We investigate the model of "reversible ratchet" with interacting particles, presented by us earlier [F. Slanina, EPL 84, 50009 (2008)]. We further clarify the effect of efficiency enhancement due to interaction and show that it is of energetic origin, rather than a consequence of reduced fluctuations. We also show complicated structures emerging in the interaction and density dependence of the...

In this contribution, I summarise the studies of the properties of Bose-Einstein condensed systems composed of up to twelve pions or kaons carried out by the NPLQCD collaboration. These investigations have provided precise determination the I=2 ππ and I=1 KK scattering lengths and the first determination of three-hadron interactions from QCD, finding a repulsive threepion interaction of size co...

Sensitive dependence of the electronic structure on the number of layers in few-layer phosphorene raises a question about the true nature of the interlayer interaction in so-called "van der Waals (vdW) solids". We performed quantum Monte Carlo calculations and found that the interlayer interaction in bulk black phosphorus and related few-layer phosphorene is associated with a significant charge...

We describe the liquid-gas transition in the hard sphere system with Yukawa tail interactions in the mean spherical approximation. The dependence of critical temperature and density on the range of the interaction is shown and the spinodal curve for a short-ranged potential and a long-ranged potential is presented. The compressibility, energy and virial pressures are presented for a long-ranged...

The interaction of hydrogen molecules with clean and hydrogen-precovered surfaces has been studied using ab initio molecular dynamics simulations based on density functional theory. In particular, the dependence of the dissociative adsorption probability on the hydrogen coverage and the relaxation of hot hydrogen atoms after dissociation have been addressed. The simulations unravel the crucial ...

We study exciton-polariton nonlinear optical fluids in the high momentum waveguide regime for the first time. We demonstrate the formation of dark solitons with the expected dependence of width on fluid density for both main classes of soliton-forming fluid defects. The results are well described by numerical modeling of the fluid propagation. We deduce a continuous wave nonlinearity more than ...

A saturating hamiltonian is presented in a relativisti-cally covariant formalism. The interaction is described by scalar and vector mesons, with coupling strengths adjusted to the nuclear matter. No explicit density dependence is assumed. The hamilto-nian is applied in a QMD calculation to determine the fragment distribution in O + Br collision at diierent energies (50 { 200 MeV/u) to test the ...

Population density regulation is a fundamental principle in ecology, but the specific process underlying functional expression of density dependence remains to be fully elucidated. One view contends that patterns of density dependence are largely fixed across a species irrespective of environmental conditions, whereas another is that the strength and expression of density dependence are fundame...

We consider an atomistic model defined through an interaction field satisfying a variational principle, and can therefore be considered a toy model of (orbital free) density functional theory. We investigate atomistic-to-continuum coupling mechanisms for this atomistic model, paying special attention to the dependence of the atomistic subproblem on the atomistic region boundary and the boundary...

Within the adiabatic approximation, time-dependent density functional theory yields only single excitations. Near states of double excitation character, the exact exchange-correlation kernel has a strong dependence on frequency. We derive the exact frequency-dependent kernel when a double excitation mixes with a single excitation, well separated from the other excitations, in the limit that the...