Random sequential adsorption of lattice animals on a three-dimensional cubic lattice.

The properties of the random sequential adsorption of objects of various shapes on simple three-dimensional (3D) cubic lattice are studied numerically by means of Monte Carlo simulations. Depositing objects are "lattice animals," made of a certain number of nearest-neighbor sites on a lattice. The aim of this work is to investigate the impact of the geometrical properties of the shapes on the jamming density θ_{J} and on the temporal evolution of the coverage fraction θ(t).

Goal-oriented attentional self-regulation training in individuals with acquired brain injury in a subacute phase: a pilot feasibility study.

The primary aim of this prospective pilot study was to assess feasibility of implementing goal-oriented attentional self-regulation (GOALS) training in Slovenia with patients with multiple cognitive deficits after acquired brain injury in acute phase of recovery. Seven patients with acquired brain injury (i.e.

A Cloud-Based Virtual Reality App for a Novel Telemindfulness Service: Rationale, Design and Feasibility Evaluation.

Background: Worldwide, there has been a marked increase in stress and anxiety, also among patients with traumatic brain injury (TBI). Access to psychology services is limited, with some estimates suggesting that over 50% of sufferers are not accessing the existing services available to them for reasons such as inconvenience, embarrassment, or stigmatization concerns around mental health. Health service providers have increasingly been turning to drug-free therapies, such as mindfulness programs, as complementary treatments.

Particle morphology effects in random sequential adsorption.

The properties of the random sequential adsorption of objects of various shapes on a two-dimensional triangular lattice are studied numerically by means of Monte Carlo simulations. The depositing objects are formed by self-avoiding lattice steps, whereby the size of the objects is gradually increased by wrapping the walks in several different ways. The aim of this work is to investigate the impact of the geometrical properties of the shapes on the jamming density θ_{J} and on the temporal evolution of the coverage fraction θ(t).

Adsorption-desorption processes of polydisperse mixtures on a triangular lattice.

Adsorption-desorption processes of polydisperse mixtures on a triangular lattice are studied by numerical simulations. Mixtures are composed of the shapes of different numbers of segments and rotational symmetries. Numerical simulations are performed to determine the influence of the number of mixture components and the length of the shapes making the mixture on the kinetics of the deposition process.

Structural characterization of submerged granular packings.

We consider the impact of the effective gravitational acceleration on microstructural properties of granular packings through experimental studies of spherical granular materials saturated within fluids of varying density. We characterize the local organization of spheres in terms of contact connectivity, distribution of the Delaunay free volumes, and the shape factor (parameter of nonsphericity) of the Voronoï polygons. The shape factor gives a clear physical picture of the competition between less and more ordered domains of particles in experimentally obtained packings.

Optimization of the monolayer growth in adsorption-desorption processes.

Kinetics of the deposition process of dimers in the presence of desorption is studied by Monte Carlo method on a one-dimensional lattice. The aim of this work is to investigate how do various temporal dependencies of the desorption rate hasten or slow down the deposition process. The growth of the coverage θ(t) above the jamming limit to its steady-state value θ(∞) is analyzed when the desorption probability P(des) decreases both stepwise and linearly (continuously) over a certain time domain.

Percolation in random sequential adsorption of extended objects on a triangular lattice.

The percolation aspect of random sequential adsorption of extended objects on a triangular lattice is studied by means of Monte Carlo simulations. The depositing objects are formed by self-avoiding lattice steps on the lattice. Jamming coverage θ{jam}, percolation threshold θ{p}, and their ratio θ{p}/θ{jam} are determined for objects of various shapes and sizes.

Simulation study of anisotropic random sequential adsorption of extended objects on a triangular lattice.

The properties of the anisotropic random sequential adsorption (RSA) of objects of various shapes on a two-dimensional triangular lattice are studied numerically by means of Monte Carlo simulations. The depositing objects are formed by self-avoiding lattice steps, whereby the first step determines the orientation of the object. Anisotropy is introduced by positing unequal probabilities for orientation of depositing objects along different directions of the lattice.

Relaxation properties in a diffusive model of k-mers with constrained movements on a triangular lattice.

We study the relaxation process in a two-dimensional lattice gas model, based on the concept of geometrical frustration. In this model the particles are k-mers that can both randomly translate and rotate on the planar triangular lattice. In the absence of rotation, the diffusion of hard-core particles in crossed single-file systems is investigated.

Adsorption, desorption, and diffusion of k-mers on a one-dimensional lattice.

Kinetics of the deposition process of k -mers in the presence of desorption or/and diffusional relaxation of particles is studied by Monte Carlo method on a one-dimensional lattice. For reversible deposition of k-mers, we find that after the initial "jamming," a stretched exponential growth of the coverage theta(t) toward the steady-state value theta(eq) occurs, i.e.

Random sequential adsorption of polydisperse mixtures on discrete substrates.

We study random sequential adsorption of polydisperse mixtures of extended objects both on a triangular and on a square lattice. The depositing objects are formed by self-avoiding random walks on two-dimensional lattices. Numerical simulations were performed to determine the influence of the number of mixture components and length of the shapes making the mixture on the kinetics of the deposition process.

Upward penetration of grains through a granular medium.

We study experimentally the creeping penetration of guest (percolating) grains through densely packed granular media in two dimensions. The evolution of the system of the guest grains during the penetration is studied by image analysis. To quantify the changes in the internal structure of the packing, we use Voronoï tessellation and a certain shape factor which is a clear indicator of the presence of different underlying substructures (domains).

Reversible random sequential adsorption of mixtures on a triangular lattice.

Reversible random sequential adsorption of binary mixtures of extended objects on a two-dimensional triangular lattice is studied numerically by means of Monte Carlo simulations. The depositing objects are formed by self-avoiding lattice steps. We concentrate here on the influence of the symmetry properties of the shapes on the kinetics of the adsorption-desorption processes in two-component mixtures.

Simulation study of random sequential adsorption of mixtures on a triangular lattice.

Random sequential adsorption of binary mixtures of extended objects on a two-dimensional triangular lattice is studied numerically by means of Monte Carlo simulations. The depositing objects are formed by self-avoiding random walks on the lattice. We concentrate here on the influence of the symmetry properties of the shapes on the kinetics of the deposition processes in two-component mixtures.

Simulation study of granular compaction dynamics under vertical tapping.

We study, by numerical simulation, the compaction dynamics of frictional hard disks in two dimensions, subjected to vertical shaking. Shaking is modeled by a series of vertical expansion of the disk packing, followed by dynamical recompression of the assembly under the action of gravity. The second phase of the shake cycle is based on an efficient event-driven molecular-dynamics algorithm.

Symmetry effects in reversible random sequential adsorption on a triangular lattice.

Reversible random sequential adsorption of objects of various shapes on a two-dimensional triangular lattice is studied numerically by means of Monte Carlo simulations. The growth of the coverage rho(t) above the jamming limit to its steady-state value rho(infinity) is described by a pattern rho(t) = rho(infinity - deltarhoE(beta)[-(t/tau)beta], where E(beta) denotes the Mittag-Leffler function of order beta element of (0, 1). The parameter tau is found to decay with the desorption probability P_ according to a power law tau = AP_(-gamma).

Memory effects in vibrated granular systems: response properties in the generalized random sequential adsorption model.

We investigate, by numerical simulation, the dynamical response of a granular system to an abrupt change in shaking intensity within the framework of the reversible random sequential adsorption models. We analyse the two-dimensional lattice model in which, in addition to the adsorption-desorption process, there is diffusion of the adsorbed particles on the surface. Our model reproduces qualitatively the densification kinetics and the memory effects of vibrated granular materials.

Transport theory of granular swarms.

The transport of trace granular gas (swarm) in a carrier granular fluid is studied by means of the Boltzmann-Lorentz kinetic equation. Time-dependent perturbation theory is used to follow the evolution of the granular swarm from an arbitrary initial distribution. A nonhydrodynamic extension of the diffusion equation is derived, with transport coefficients that are time dependent and implicitly depend on the wave vector.