This work is devoted to 2D dispersing billiards with smooth boundary, i.e. periodic Lorentz gases (with and without horizon). We revisit several fundamental properties of these systems and make a number of improvements. The necessity of such improvements became obvious during our recent studies of gases of several particles [CD]. We prove here that local (stable and unstable) manifolds, as well...

Olfactory display devices have become a recent demand and trend in human computer interaction, providing a new member in the human computer interaction peripheral devices family. These devices enrich the olfactory sense for the user stimulating him/her by means of scent stimuli in correspondence to an object or an event shown on the visual display. Some researches have been done to cover the de...

Let f : [0,+∞) −→ (0,+∞) be a sufficiently smooth convex function, vanishing at infinity. Consider the planar domain Q delimited by the positive x-semiaxis, the positive y-semiaxis, and the graph of f . Under certain conditions on f , we prove that the billiard flow in Q has a hyperbolic structure and, for some examples, that it is also ergodic. This is done using the cross section correspondin...

Dispersal delays are introduced into a competition model for two species that disperse among n identical patches. The model is formulated as a system of integro-differential equations with an arbitrary distribution of dispersal times between patches. By identifying steady states and analyzing local stability, conditions for competitive exclusion, coexistence or extinction are determined in term...

1. We discuss aspects of resource selection based on observing a given vector of resource variables for different individuals at discrete time steps. A new technique for estimating preference of habitat characteristics, applicable when there are multiple individual observations, is proposed. 2. We first show how to estimate preference on the population and individual level when only a single si...

Inelastic neutron scattering measurements on Ba(Fe0.963Ni0.037)2As2 manifest a neutron spin resonance in the superconducting state with anisotropic dispersion within the Fe layer. Whereas the resonance is sharply peaked at the antiferromagnetic (AFM) wave vector Q(AFM) along the orthorhombic a axis, the resonance disperses upwards away from Q(AFM) along the b axis. In contrast to the downward d...

There is a need for better description and heuristic understanding of the sustainability of populations connected over space by a dispersing stage, both for management purposes and to increase our basic knowledge of the dynamics of these populations. We show that persistence of such a population of connected subpopulations depends on whether the sum of the reproductive gains through all possibl...

the present study investigates the possibility of using poloxamers as solubility and dissolution rate enhancing agents of poorly water soluble bioactive constituent patchouli alcohol (pa) that can be used for the preparation of immediate release pellets formulation. two commercially available grades poloxamer 188 (p 188) and poloxamer 407 (p 407) were selected, and solid dispersions (sds) conta...

The evolutionary stability of fruit-eating birds is linked to their role in dispersing seeds