Now showing items 1-16 of 16

    • Differential susceptibility to noise of mixed Turing and Hopf modes in a photosensitive chemical medium 

      Alonso Muñoz, Sergio; Míguez, David G.; Sagués Mestres, Francesc (2007-12-31)
      Article
      Open Access
      We report on experiments with the photosensitive chlorine dioxide-iodine-malonic acid reaction (CDIMA) when forced with a random (spatiotemporally) distributed illumination. Acting on a mixed mode consisting of oscillating ...
    • Direct measurement of Lighthill’s energetic efficiency of a minimal magnetic microswimmer 

      Calero, Carles; García Torres, José Manuel; Ortiz Ambriz, Antonio; Sagués Mestres, Francesc; Pagonabarraga, I.; Tierno, Prieto (2019-09-27)
      Article
      Open Access
      The realization of artificial microscopic swimmers able to propel in viscous fluids is an emergent research field of fundamental interest and vast technological applications. For certain functionalities, the efficiency ...
    • Excitability transitions and wave dynamics under spatiotemporal structured noise 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc; Sancho Herrero, José María (2002-06-14)
      Article
      Open Access
      We present an analytic and numerical study of the effects of external fluctuations in active media. Our analytical methodology transforms the initial stochastic partial differential equations into an effective set of ...
    • Expanding scroll rings and negative tension turbulence in a model of excitable media 

      Alonso Muñoz, Sergio; Kähler, Ralf; Mikhailov, Alexander S; Sagués Mestres, Francesc (2004-11-03)
      Article
      Open Access
      Scroll waves in excitable media, described by the Barkley model, are studied. In the parameter region of weak excitability, negative tension of wave filaments is found. It leads to expansion of scroll rings and instability ...
    • Experimental evidence of localized oscillations in the photosensitive chlorine dioxide-iodine-malonic acid reaction 

      Míguez, David G.; Alonso Muñoz, Sergio; Pérez Muñuzuri, Alberto; Sagués Mestres, Francesc (American Institute of Physics (AIP), 2006-10-24)
      Article
      Open Access
      The interaction between Hopf and Turing modes has been the subject of active research in recent years. We present here experimental evidence of the existence of mixed Turing-Hopf modes in a two-dimensional system. Using ...
    • Magnetically tunable bidirectional locomotion of a self-assembled nanorod-sphere propeller 

      García Torres, José Manuel; Calero, Carles; Sagués Mestres, Francesc; Pagonabarraga, I.; Tierno, Prieto (2018-04-25)
      Article
      Open Access
      Field-driven direct assembly of nanoscale matter has impact in disparate fields of science. In microscale systems, such concept has been recently exploited to optimize propulsion in viscous fluids. Despite the great ...
    • Negative-tension instability of scroll waves and Winfree turbulence in the Oregonator model 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc; Mikhailov, Alexander S (2006-10-06)
      Article
      Open Access
      Excitable media support self-organized scroll waves which can be unstable and give rise to three-dimensional wave chaos. Winfree turbulence of scroll waves results from the negative-tension instability of scroll waves; it ...
    • Noise-induced Brownian motion of spiral waves 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc (2001-03-20)
      Article
      Open Access
      We study the erratic displacement of spiral waves forced to move in a medium with random spatiotemporal excitability. Analytical work and numerical simulations are performed in relation to a kinematic scheme, assumed to ...
    • Noise-reversed stability of Turing patterns versus Hopf oscillations near codimension-two conditions 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc (2009-09-21)
      Article
      Open Access
      Pattern formation induced by noise is a celebrated phenomenon in diverse reaction-diffusion systems. Here we report numerical simulations with the Lengyel-Epstein model for the chlorine dioxide-iodine-malonic acid reaction ...
    • Periodic forcing of scroll rings and control of Winfree turbulence in excitable media 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc; Mikhailov, Alexander S (Institute of Physics (IOP), 2006-06-23)
      Article
      Open Access
      By simulations of the Barkley model, action of uniform periodic nonresonant forcing on scroll rings and wave turbulence in three-dimensional excitable media is investigated. Sufficiently strong rapid forcing converts ...
    • Regular wave propagation out of noise in chemical active media 

      Alonso Muñoz, Sergio; Sendiña, Irene; Perez Muñuzuri, Vicente; Sancho Herrero, José María; Sagués Mestres, Francesc (American Institute of Physics (AIP), 2001-07-30)
      Article
      Open Access
      A pacemaker, regularly emitting chemical waves, is created out of noise when an excitable photosensitive Belousov-Zhabotinsky medium, strictly unable to autonomously initiate autowaves, is forced with a spatiotemporal ...
    • Scroll wave instability controlled by external fluctuations 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc; Sancho Herrero, José María (2005-06-01)
      Article
      Open Access
      Scroll waves, a characteristic dynamical pattern of three-dimensional excitable media, exhibit an instability under low excitability conditions. This unstable regime can be partially controlled by using random forcing in ...
    • Suppression of scroll wave turbulence by noise 

      Alonso Muñoz, Sergio; Sancho Herrero, José María; Sagués Mestres, Francesc (2004-12-02)
      Article
      Open Access
      Rotating scroll waves are dynamical spatiotemporal structures characteristic of three-dimensional active media. It is well known that, under low excitability conditions, scroll waves develop an intrinsically unstable ...
    • Swimming modes of self-assembled magnetic micropropeller 

      Calero, Carles; García Torres, José Manuel; Sagués Mestres, Francesc; Pagonabarraga, I.; Tierno, Prieto (2018)
      Conference report
      Open Access
    • Taming Winfree turbulence of scroll waves in excitable media 

      Alonso Muñoz, Sergio; Sagués Mestres, Francesc; Mikhailov, Alexander S (2003-03-14)
      Article
      Open Access
      Winfree turbulence of scroll waves is a special kind of spatiotemporal chaos that exists exclusively in three-dimensional excitable media and is currently considered one of the principal mechanisms of cardiac fibrillation. ...
    • Wave pattern dynamics in fluctuating media 

      Sagués Mestres, Francesc; Alonso Muñoz, Sergio; Sancho Herrero, José María (2002-11-01)
      Article
      Open Access
      Analytical and numerical results on the ordering role of external random fluctuations in excitable systems are presented. Our study focuses on a simple model for excitable systems. Regular waves are created and sustained ...