Biomedical subjects

P Tolédano

Publications and source records attributed to P Tolédano.

15 recordsLinked to original sources

PubMed2005

Theory of the cooperative evaporation of volatile droplets.

A theoretical approach to the cooperative process of evaporation of volatile liquid droplet arrays is proposed which combines the equation of the liquid-gas interface with a Landau-type description. The spatial and temporal behaviors of the process are shown to be governed by the spontaneous symmetry breaking mechanism of a parent droplet configuration. The applicability of the approach is illustrated by the theoretical description of recent experiments in closed and open systems.

Journal Article↗

PubMed2004

Theory of the incommensurate smectic-A phases in dimesogenic liquid crystals.

A mechanism assuming a mismatch between the basic smectic periodicity and the amplitude and phase modulations periods of the mass density wave order parameter is proposed, for describing the incommensurate smectic-A structure found in dimesogenic liquid crystals. The different sequences of phases found in this family of compounds are described theoretically.

Journal Article↗

PubMed2002

Unusual sequences of tilted smectic phases in liquid crystals of bent-shape molecules.

The first theoretical description of the experimentally often-observed isotropic-polar smectic phase transitions of symmetric and asymmetric bent-shape molecules is presented. The isotropic-tilted polar smectic phase transition requires a coupling among three types of ordering processes: polar packing, director tilt, and layer ordering. For explaining the unusual triclinic-monoclinic phase transition with the lower symmetry phase at higher temperature, observed in fluoro-containing compounds recently, a mechanism is proposed in which the layer ordering triggers the simultaneous onset of the tilt and polar order.

Journal Article↗

PubMed1999

Symmetries and induced effects in bilayer and multilayer antiferroelectric and ferrielectric liquid crystal phases.

The stable antiferroelectric and ferrielectric smectic phases which may arise below a chiral SmA* phase are investigated theoretically. The symmetry and physical properties of the bilayer and multilayer configurations are worked out. Antiferroelectric and ferrielectric bilayer and multilayer configurations, possessing an induced spontaneous ferroelectric polarization component perpendicular to the smectic layers, are shown to take place, as the result of a nonlinear piezoelectric effect. These states of low polar symmetries occur when the angle between the inlayer projections of the dipoles and the director of the molecules is different from 90 degrees.

Journal Article↗

PubMed1996