Browsing by Author "Sancho, Jose Maria"

Diffusion coefficient in periodic and random potentials
Khoury, M; Gleeson, James P.; Sancho, Jose Maria; Lacasta Palacio, Ana María; Lindenberg, K (2009)
Article
Open Access 
Diffusion on Solid Surface: anomalous is Normal
Sancho, Jose Maria; Lacasta Palacio, Ana María; Lindenberg, K.; Sokolov, Igor M.; Romero, A. H. (American Physical Society, 20040623)
Article
Open AccessWe present a numerical study of classical particles diffusing on a solid surface. The particles’ motion is modeled by an underdamped Langevin equation with ordinary thermal noise. The particlesurface interaction is described ... 
Dispersionless transport in a washboard potential
Lindenberg, K.; Sancho, Jose Maria; Lacasta Palacio, Ana María; Sokolov, Igor M. (American Physical Society, 20070110)
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Open AccessWe study and characterize a new dynamical regime of underdamped particles in a tilted washboard potential. We find that for small friction in a finite range of forces the particles move essentially nondispersively, that ... 
Domain growth in binary mixtures at low temperatures
Lacasta Palacio, Ana María; Hernández Machado, Aurora; Sancho, Jose Maria; Toral Garcés, Raúl (The American Physical Society, 19920301)
Article
Open AccessWe have studied domain growth during spinodal decomposition at low temperatures. We have performed a numerical integration of the deterministic timedependent GinzburgLandau equation with a variable, concentrationdependent ... 
Dynamics of an inchworm nanowalker
Ciudad Álvarez, Aleix; Sancho, Jose Maria; Lacasta Palacio, Ana María (Elsevier Science, 20060519)
Article
Open AccessAn inchworm processive mechanism is proposed to explain the motion of dimeric molecular motors such as kinesin.We present here preliminary results for this mechanism focusing on observables like mean velocity, coupling ... 
Effective diffusion in a stochastic velocity field
Careta i Pons, Agustí; Sagués Mestre, Francesc; Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (Springer Verlag, 19930401)
Article
Restricted access  publisher's policyAnalytical results are derived for the effective dispersion of a passive scalar in a stochastic velocity field evolving in a fast time scale. These results are favorably compared with direct computer simulation of ... 
Effects of domain morphology in phaseseparation dynamics at low temperature.
Lacasta Palacio, Ana María; Sancho, Jose Maria; Hernández Machado, Aurora; Toral, Raul. (American Physical Society, 19930901)
Article
Open AccessWe present numerical results of the deterministic GinzburgLandau equation with a concentrationdependent diffusion coefficient, for different values of the volume fraction phi of the minority component. The morphology of ... 
Escape over a potential barrier driven by colored noise: large but finite correlation time
de la Rubia, Francisco Javier; PeacockLópez, E.; Tsironis, G P; Lindenberg, Katja; Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (1988)
Article
Open AccessThe recent theory of Tsironis and Grigolini for the mean firstpassage time from one metastable state to another of a bistable potential for long correlation times of the noise is extended to large but finite correlation times. 
Evaporation and coarsening dynamics with open boundaries
Lacasta Palacio, Ana María; Sagués Mestre, Francesc; Sancho, Jose Maria; Sokolov, Igor M. (Americah Physical Society, 19990131)
Article
Open AccessWe present a study of the evaporation dynamics of a substance undergoing a coarsening process. The system is modeled by the CahnHilliard equation with absorbing boundaries. We have found that the dynamics, although of ... 
Exported oscillator competition: a concept to analyze complex rhythms
Lacasta Palacio, Ana María; Sancho, Jose Maria; Sagués Mestre, Francesc (American Physical Society, 2005)
Article
Open AccessWe study the interaction between two independent nonlinear oscillators competing through a neutral excitable element. The first oscillator, completely deterministic, acts as a normal pacemaker sending pulses to the neutral ... 
External fluctuations in front propagation
Armero Rovira, J.; Sancho, Jose Maria; Casademunt, Jaume; Lacasta Palacio, Ana María; Ramírez de la Piscina Millán, Laureano; Sagués Mestre, Francesc (American Physical Society, 19960401)
Article
Open AccessWe study the effects of external noise in a onedimensional model of front propagation. Noise is introduced through the fluctuations of a control parameter leading to a multiplicative stochastic partial differential equation. ... 
Firstpassage time in a bistable potential with colored noise
Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria; de la Rubia, Francisco Javier; Lindenberg, Katja; Tsironis, G P (19890815)
Article
Open AccessA precise digital simulation of a bistable system under the effect of colored noise is carried out. A set of data for the mean firstpassage time is obtained. The results are interpreted and compared with presently available ... 
Firstpassage times for a marginal state driven by colored noise
Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (The American Physical Society, 19910118)
Article
Open AccessThe dynamical process through a marginal state (saddle point) driven by colored noise is studied. For small correlation time of the noise, the mean firstpassage time and its variance are calculated using standard methods. ... 
Fluctuations in domain growth: GinzburgLandau equations with multiplicative noise
Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria; Hernández Machado, Aurora (The American Physical Society, 19930701)
Article
Open AccessGinzburgLandau equations with multiplicative noise are considered, to study the effects of fluctuations in domain growth. The equations are derived from a coarsegrained methodology and expressions for the resulting ... 
From subdiffusion to superdiffusion of particles on solid surfaces
Lacasta Palacio, Ana María; Sancho, Jose Maria; Sokolov, Igor M.; Lindenberg, K. (American Physical Society, 20041115)
Article
Open AccessWe present a numerical and partially analytical study of classical particles obeying a Langevin equation that describes diffusion on a surface modeled by a two dimensional potential. The potential may be either periodic ... 
Front and domain growth in the presence of gravity.
Lacasta Palacio, Ana María; HernándezMachado, Aurora; Sancho, Jose Maria (American Physical Society, 19931001)
Article
Open AccessFront and domain growth of a binary mixture in the presence of a gravitational field is studied. The interplay of bulk (and surface) diffusion mechanisms is analyzed. An equation for the evolution of interfaces is derived ... 
Front propagation in spatially modulated media
Armero, J.; Lacasta Palacio, Ana María; Ramírez de la Piscina Millán, Laureano; Casademunt, Jaume; Sancho, Jose Maria; Sagués Mestre, Francesc (American Physical Society, 19970901)
Article
Open AccessA twodimensional reactiondiffusion front which propagates in a modulated medium is studied. The modulation consists of a spatial variation of the local front velocity in the transverse direction to that of the ... 
Generation of spatiotemporal colored noise
García Ojalvo, Jordi; Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (American Physical Society, 19921001)
Article
Open AccessWe develop an algorithm to simulate a Gaussian stochastic process that is nonδcorrelated in both space and time coordinates. The colored noise obeys a linear reactiondiffusion Langevin equation with Gaussian white noise. ... 
Higher order colored noise effects in multivariable systems.
Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (American Physical Society, 19880601)
Article
Open AccessWe extend the partial resummation technique of FokkerPlanck terms for multivariable stochastic differential equations with colored noise. As an example, a model system of a Brownian particle with colored noise is studied. ... 
Implementación de los métodos de RiksWempner, BatozDhatt, PowellSimons y otros en el programa de elementos finitos F.E.A.P
Sancho, Jose Maria; Ortiz, Jesús (20090309T16:16:24Z)
Article
Open AccessLos fundamentos teóricos del método de Riks y su utilidad para el paso de puntos límite en el análisis no lineal de estructuras, están actualmente bien establecidos, pero resta aún una importante labor de normalización y ...