Exploració per autor "Sancho, Jose Maria"

Ara es mostren els items 18-37 de 47

    • First-passage times for a marginal state driven by colored noise 

      Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (The American Physical Society, 1991-01-18)
      Article
      Accés obert
      The dynamical process through a marginal state (saddle point) driven by colored noise is studied. For small correlation time of the noise, the mean first-passage time and its variance are calculated using standard methods. ...

    • Fluctuations in domain growth: Ginzburg-Landau equations with multiplicative noise 

      Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria; Hernández Machado, Aurora (The American Physical Society, 1993-07-01)
      Article
      Accés obert
      Ginzburg-Landau equations with multiplicative noise are considered, to study the effects of fluctuations in domain growth. The equations are derived from a coarse-grained 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, 2004-11-15)
      Article
      Accés obert
      We 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; Hernández-Machado, Aurora; Sancho, Jose Maria (American Physical Society, 1993-10-01)
      Article
      Accés obert
      Front 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, 1997-09-01)
      Article
      Accés obert
      A two-dimensional reaction-diffusion 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, 1992-10-01)
      Article
      Accés obert
      We develop an algorithm to simulate a Gaussian stochastic process that is non-δ-correlated in both space and time coordinates. The colored noise obeys a linear reaction-diffusion 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, 1988-06-01)
      Article
      Accés obert
      We extend the partial resummation technique of Fokker-Planck 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 Riks-Wempner, Batoz-Dhatt, Powell-Simons y otros en el programa de elementos finitos F.E.A.P 

      Sancho, Jose Maria; Ortiz, Jesús (1991)
      Article
      Accés obert
      Los 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 ...

    • Langevin dynamics of A+A reactions in one dimension 

      Sancho, Jose Maria; Romero, A. H.; Lacasta Palacio, Ana María; Lindenberg, Katja (IOP Publishing, 2007-02-28)
      Article
      Accés obert
      We propose a set of Langevin equations of motion together with a reaction rule for the study of binary reactions. Our scheme is designed to address this problem for arbitrary friction ° and temperature T. It easily ...

    • Langevin equations with multiplicative noise: application to domain growth 

      Sancho, Jose Maria; Hernández-Machado, A.; Ramírez de la Piscina Millán, Laureano; Lacasta Palacio, Ana María (Jagiellonian University, Polish Academy of Arts and Sciences, 1993-05-01)
      Article
      Accés obert
      Langevin Equations of Ginzburg--Landau form, with multiplicative noise, are proposed to study the effects of fluctuations in domain growth. These equations are derived from a coarse-grained methodology. The Cahn--Hiliard--Cook ...

    • Modelization of surface diffusion of a molecular dimer 

      Romero, A. H.; Lacasta Palacio, Ana María; Sancho, Jose Maria (American Physical Society, 2004-05-20)
      Article
      Accés obert
      A simple model for a dimer molecular diffusion on a crystalline surface, as a function of temperature, is presented. The dimer is formed by two particles coupled by a quadratic potential. The dimer diffusion is modeled by ...

    • Numerical algorithm for Ginzburg-Landau equations with multiplicative noise: application to domain growth 

      Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria; Hernández Machado, Aurora (The American Physical Society, 1993-07-01)
      Article
      Accés obert
      We consider stochastic partial differential equations with multiplicative noise. We derive an algorithm for the computer simulation of these equations. The algorithm is applied to study domain growth of a model with a ...

    • Numerical study of A+A -> 0 and A+B ->0 reactions with inertia 

      Romero, A. H.; Lacasta Palacio, Ana María; Sancho, Jose Maria; Lindenberg, Katja (American Institute of Physics, 2007-11-30)
      Article
      Accés obert
      Using numerical methods we study the annihilation reactions A + A → 0 and A + B → 0 in one and two dimensions in the presence of inertial contributions to the motion of the particles. The particles move freely following ...

    • Particle separation by external fields on periodic surfaces 

      Sancho, Jose Maria; Khoury, M.; Lindenberg, K.; Lacasta Palacio, Ana María (http://dx.doi.org/10.1063/1.478548, 2005-11-30)
      Article
      Accés obert
      Particles moving on perfect periodic surfaces under the influence of external forces may move along directions that deviate from that of the force. We briefly recall previous results for transport of particles on surfaces ...

    • Pattern and velocity selection of fronts propagating in modulated media 

      Armero, J.; Lacasta Palacio, Ana María; Ramírez de la Piscina Millán, Laureano; Casademunt, Jaume; Sancho, Jose Maria; Sagués Mestre, Francesc (EDP Sciences, 1996-02-01)
      Article
      Accés obert
      We study the problem of pattern and velocity selection of morphologically stable two-dimensional fronts propagating in a spatially modulated medium. The generic system is governed by a local equation and evolves towards a ...

    • Phase separation driven by external fluctuations 

      García Ojalvo, Jordi; Lacasta Palacio, Ana María; Sancho, Jose Maria; Toral, R. (EDP Sciences, 1998-04-30)
      Article
      Accés obert
      The influence of external fluctuations in phase separation processes is analysed. These fluctuations arise from random variations of an external control parameter. A linear stability analysis of the homogeneous state ...

    • Phase separation dynamics in a concetration gradient 

      Lacasta Palacio, Ana María; Sancho, Jose Maria; Yeung, C. (EDP Sciences, 1994-08-01)
      Article
      Accés obert
      Phase separation dynamics with an initially nonuniform concentration are studied. Critical and off-critical behavior is observed simultaneously. A mechanism for an expanding phase-separated region is demonstrated and the ...

    • Phase separation dynamics under stirring 

      Lacasta Palacio, Ana María; Sancho, Jose Maria; Sagués Mestre, Francesc (American Physical Society, 1995-08-01)
      Article
      Accés obert
      Phase separation dynamics in the presence of externally imposed stirring is stuidied. The stirring is assumed independent of the concentration and it is generated with a well-defined energy spectrum. The domain growth ...

    • Physical analysis of a processive molecular motor: the conventional kinesin 

      Alva, Aleix; Lacasta Palacio, Ana María; Sancho, Jose Maria (American Physical Society, 2005-09-29)
      Article
      Accés obert
      We present a model that allows for the derivation of the experimentally accesible observables: spatial steps, mean velocity, stall force, useful power, efficiency and randomness, etc. as a function of the adenosine triphosphate ...

    • Sorting of mesoscopic particles driven through periodic potential landscapes 

      Lacasta Palacio, Ana María; Khoury, M.; Sancho, Jose Maria; Lindenberg, Katja (World Scientific Publishing, 2006-10-01)
      Article
      Accés obert
      Sorting of colloidal particles of different sizes is of importance in the transport and delivery of such particles in biological, materials science, and other technological contexts. A successful methodology involves the ...