Biomedical subjects

S Rica

Publications and source records attributed to S Rica.

11 recordsLinked to original sources

PubMed2005

Self-diffusion of particles in gas-driven granular layers with periodic flow modulation.

We study self-diffusion of particles in gas-driven granular layers by high-speed fluorescent video microscopy. We show that periodic flow modulation results in an enhancement of the particle's diffusion. The diffusion enhancement, which in turn is an indication of more efficient fluidization of the granular layer, is associated with the onset of disordered subharmonic patterns. Our measurements provide a sensitive characterization method of the fluidization properties of particulate-gas systems.

Journal Article↗

PubMed2005

Self-organized origami.

In origami, form follows the sequential spatial organization of folds. This requires continuous intervention and raises a natural question: Can origami arise through self-organization? We answer this affirmatively by examining the possible physical origin for the Miura-ori leaf-folding patterns that arise naturally in insect wings, leaves, and other laminae-like organelles. In particular, we point out examples where biaxial compression of an elastically supported thin film, such as that due to differential growth, shrinkage, desiccation, or thermal expansion, spontaneously generates these patterns, and we provide a simple theoretical explanation for their occurrence.

Betulaceae↗

PubMed2000

Nonlinear Schrodinger flow in a periodic potential

We report a study of solutions of the defocusing nonlinear Schrodinger equation in a spatially periodic potential. The ground-state solution and the steady flows of the system are studied analytically. Above a critical current, a steady state no longer exists and time-dependent solutions are generated, which are numerically simulated and described.

Journal Article↗

PubMed1995