Biomedical subjects

IM Sokolov

Publications and source records attributed to IM Sokolov.

15 recordsLinked to original sources

PubMed2000

Two-photon coherent control of atomic collisions by light with entangled polarization

We describe a new method of coherent optical control of internal dynamics of atomic collisions by means of two correlated light beams having entangled polarizations. We show that, if excitation of a colliding pair of atoms is by two photons having entangled polarizations, it is possible to redirect the output fragments of the collision into certain channels with a selected type of internal transition symmetry. The transition symmetry is defined in the body-fixed coordinate frame which has random and originally unknown orientation in space.

Journal Article↗

PubMed2000

Front propagation in one-dimensional autocatalytic reactions: the breakdown of the classical picture at small particle concentrations

The autocatalytic scheme A+B-->2A in a discrete particle system is studied in one dimension via Monte Carlo simulations. We find considerable differences in the results for the front velocities and front forms compared to the classical, continuous picture, which is only valid in the limit of very small reaction probabilities p. Interestingly, we also obtain front propagation velocities fairly below the classical minimal velocity.

Journal Article↗

PubMed2000

Relaxation properties of small-world networks

Recently, Watts and Strogatz introduced the so-called small-world networks in order to describe systems that combine simultaneously properties of regular and random lattices. In this work we study diffusion processes defined on such structures by considering explicitly the probability for a random walker to be present at the origin. The results are intermediate between the corresponding ones for fractals and Cayley trees.

Journal Article↗

PubMed2000

Particle dispersion in synthetic turbulent flows

We study particle dispersion advected by a synthetic turbulent flow from a Lagrangian perspective and focus on the two-particle and cluster dispersion by the flow. It has been recently reported that Richardson's law for the two-particle dispersion can stem from different dispersion mechanisms, and can be dominated by either diffusive or ballistic events. The nature of the Richardson dispersion depends on the parameters of our flow and is discussed in terms of the values of a persistence parameter expressing the relative importance of the two above-mentioned mechanisms. We support this analysis by studying the distribution of interparticle distances, the relative velocity correlation functions, as well as the relative trajectories.

Journal Article↗

PubMed2000

Two scaling domains in multiple cracking phenomena

The fragmentation of two-phase composite systems such as coatings on substrates and fibers in matrices under uniaxial tension shows two regimes: the evolution of the mean fragment length with applied strain displays different power laws for small and for large strains. From theoretical arguments, we find that in both cases the scaling exponent depends on the shape parameter of the strength distribution. The exponent for large applied strains depends also, as we show, on the way (linear or nonlinear) in which the stress transfer between the two constituents takes place. We present experimental data on the sequential cracking of SiOx coatings on thermoplastic substrates that indeed show the two regimes; the detailed analysis of the data supports our theory.

Journal Article↗

PubMed1996