## Agustín Membiela – Investigador

E-MAIL: membiela@ifimar-conicet.gob.ar

TEL: **+54 9 223 475-5507 (int 23)**

**Investigador Asistente (CONICET)**

E-MAIL: membiela@ifimar-conicet.gob.ar

TEL: **+54 9 223 475-5507 (int 23)**

**Investigador Asistente (CONICET)**

- A. D. Sánchez, G. G. Izús, M. G. Dell’Erba, and R. R. Deza,
**A reduced gradient description of stochastic-resonant spatiotemporal patterns in a FitzHugh–Nagumo ring with electric inhibitory coupling**–Physics Letters A, vol. 378, iss. 22-23, pp. 1579-1583, 2014.

[Bibtex]`@article{Sanchez2014, author = {S\'{a}nchez, A. D. and Iz\'{u}s, Gonzalo G. and Dell'Erba, Mat\'{\i}as Germ\'{a}n and Deza, Roberto R.}, doi = {10.1016/j.physleta.2014.03.048}, file = {:opt/publicaciones/mendeley/S\'{a}nchez et al. - 2014 - A reduced gradient description of stochastic-resonant spatiotemporal patterns in a FitzHugh–Nagumo ring with.pdf:pdf}, issn = {03759601}, journal = {Physics Letters A}, keywords = {neural networks and synaptic,synchronization and coupled oscillators}, number = {22-23}, pages = {1579--1583}, publisher = {Elsevier B.V.}, title = {{A reduced gradient description of stochastic-resonant spatiotemporal patterns in a FitzHugh–Nagumo ring with electric inhibitory coupling}}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0375960114003259}, volume = {378}, year = {2014} }`

- S. E. Mangioni and R. R. Deza,
**Stabilizing transient nanopatterns in heterogeneous catalysis: A comprehensive explanation of the phenomenon**–Physica A: Statistical Mechanics and its Applications, vol. 391, iss. 17, pp. 4191-4205, 2012.

[Bibtex]`@article{Mangioni2012a, abstract = {A pattern-formation mechanism driven by attractive forces - previously studied in the context of lateral interactions between adsorbates - is reassessed through a simplified model. In its original version, such a mechanism needed an additional chemical reaction to stabilize the pattern. Recently, that goal has been achieved by means of a particular multiplicative noise. However, many details of the mechanism have remained obscure. In order to clarify them, we resorted to a simplified model that reproduces qualitatively the results of the studies carried out on the complete model. Our analysis reveals that such a mechanism may largely transcend the context in which it was found. ?? 2012 Elsevier B.V. All rights reserved.}, author = {Mangioni, Sergio E. and Deza, Roberto R.}, doi = {10.1016/j.physa.2012.04.012}, file = {:opt/publicaciones/mendeley/Mangioni, Deza - 2012 - Stabilizing transient nanopatterns in heterogeneous catalysis A comprehensive explanation of the phenomenon.pdf:pdf}, issn = {03784371}, journal = {Physica A: Statistical Mechanics and its Applications}, keywords = {Pattern formation,Stabilization by noise}, number = {17}, pages = {4191--4205}, publisher = {Elsevier B.V.}, title = {{Stabilizing transient nanopatterns in heterogeneous catalysis: A comprehensive explanation of the phenomenon}}, url = {http://dx.doi.org/10.1016/j.physa.2012.04.012}, volume = {391}, year = {2012} }`

- A. D. Sánchez, G. G. Izús, and R. R. Deza,
**Formation and synchronization of autocatalytic noise-sustained structures under Poiseuille flow**–Physica A: Statistical Mechanics and its Applications, vol. 391, iss. 16, pp. 4070-4080, 2012.

[Bibtex]`@article{Sanchez2012, abstract = {The formation and synchronization of 2D noise-sustained structures are investigated for Gray-Scott kinetics in packed-bed reactors under Poiseuille flows, when identical systems are submitted to independent spatiotemporal Gaussian white noise sources. A finite-wavelength instability is theoretically predicted and numerically confirmed for uncoupled reactors. In particular, noise-sustained structures that flow with viscous boundary conditions are numerically observed above threshold. When the systems are coupled in master-slave configuration, the numerical simulations show that the slave system replicates to a very high degree of precision the convective patterns arising in the master one due to the selective amplification of noise. The nature of the synchronization and the stability of the synchronization manifold are elucidated. © 2012 Elsevier B.V. All rights reserved.}, author = {S\'{a}nchez, Alejandro D. and Iz\'{u}s, Gonzalo G. and Deza, Roberto R.}, doi = {10.1016/j.physa.2012.01.016}, file = {:opt/publicaciones/mendeley/S\'{a}nchez, Iz\'{u}s, Deza - 2012 - Formation and synchronization of autocatalytic noise-sustained structures under Poiseuille flow.pdf:pdf}, issn = {03784371}, journal = {Physica A: Statistical Mechanics and its Applications}, keywords = {DIFICI,Gray-Scott,NSS,Stability,Synchronization}, number = {16}, pages = {4070--4080}, title = {{Formation and synchronization of autocatalytic noise-sustained structures under Poiseuille flow}}, volume = {391}, year = {2012} }`

- M. G. Dell’Erba, G. G. Izús, R. R. Deza, and H. S. Wio,
**Stochastic resonance between propagating extended attractors**-, vol. 215, pp. 214-215, 2011.

[Bibtex]`@article{DellErba2011a, author = {Dell'Erba, Mat\'{\i}as Germ\'{a}n and Izús, G. G. and Deza, R. R. and Wio, H. S.}, doi = {10.1063/1.3569503}, file = {:opt/publicaciones/mendeley/Dell'Erba et al. - 2011 - Stochastic resonance between propagating extended attractors.pdf:pdf}, isbn = {9780735408876}, keywords = {-a,05,0d,1,40,45,been done,fluctuation phenomena in statistical,in concentrated,is a well-studied phenomenon,much of the analytical,nonlinear dynamics,pacs,physics,regarding nonlinear media,sr,stochastic resonance,sys-,tems,work in sr has}, pages = {214--215}, title = {{Stochastic resonance between propagating extended attractors}}, url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.3569503}, volume = {215}, year = {2011} }`

- M. G. Dell’Erba, G. G. Izús, R. R. Deza, and H. S. Wio,
**Stochastic resonance between counterpropagating Bloch walls**–The European Physical Journal D, vol. 62, iss. 1, pp. 103-108, 2011.

[Bibtex]`@article{DellErba2011, abstract = {The nonequilibrium Ising-Bloch front bifurcation of the FitzHugh-Nagumo model with nondiffusing inhibitor provides a beautiful instance of an extended bistable system made up of propagating (Bloch) fronts. Moreover, these fronts are chiral and parity-related, and the barrier between them is nonetheless but a stationary Ising front. By means of numerical simulation in the neighborhood of this bifurcation, we demonstrate the existence of stochastic resonance in the transition between Bloch fronts of opposite chiralities, when an additive noise is included. The signal-to-noise ratio is numerically observed to scale with the distance to the critical point. This scaling law is theoretically characterized in terms of an effective nonequilibrium potential.}, author = {Dell'Erba, Mat\'{\i}as Germ\'{a}n and Iz\'{u}s, G. G. and Deza, R. R. and Wio, H. S.}, doi = {10.1140/epjd/e2010-00269-2}, file = {:opt/publicaciones/mendeley/Dell'Erba et al. - 2011 - Stochastic resonance between counterpropagating Bloch walls.pdf:pdf}, issn = {1434-6060}, journal = {The European Physical Journal D}, number = {1}, pages = {103--108}, title = {{Stochastic resonance between counterpropagating Bloch walls}}, volume = {62}, year = {2011} }`

- G. G. Izús, R. R. Deza, and A. D. Sánchez,
**Replication of noise-sustained autocatalytic chemical structures**–Journal of Chemical Physics, vol. 132, iss. 23, pp. 1-7, 2010.

[Bibtex]`@article{Deza2010, abstract = {Autocatalytic systems in a differential-flow reactor may undergo a differential-flow-induced chemical instability toward a convectively unstable regime, in which noise-sustained structures may appear. This is the case of a system with Gray-Scott kinetics in a packed-bed reactor, as reported in [B. von Haeften and G. Izus, Phys. Rev. E 67, 056207 (2003)]. In this work, two identical copies of such a system are coupled in master-slave configuration and submitted to independent spatiotemporal Gaussian white noise sources. Numerical simulation of two-dimensional reactors with uniform and Poiseuille flows reveals that the slave system replicates to a very high degree of precision and the convective patterns arising in the master one due to the presence of noise. The quality of this synchronization is assessed through several measures. A convective instability in the synchronization manifold is theoretically predicted and numerically confirmed.}, author = {Iz\'{u}s, Gonzalo G. and Deza, Roberto R. and S\'{a}nchez, Alejandro D.}, doi = {10.1063/1.3432622}, file = {:opt/publicaciones/mendeley/Iz\'{u}s, Deza, S\'{a}nchez - 2010 - Replication of noise-sustained autocatalytic chemical structures.pdf:pdf}, isbn = {1089-7690 (Electronic) 0021-9606 (Linking)}, issn = {00219606}, journal = {Journal of Chemical Physics}, number = {23}, pages = {1--7}, pmid = {20572694}, title = {{Replication of noise-sustained autocatalytic chemical structures}}, volume = {132}, year = {2010} }`

- S. E. Mangioni and R. R. Deza,
**Nonequilibrium pattern formation by subdominant attractive forces: A simple model and a stabilization strategy by means of noise**–Physical Review E – Statistical, Nonlinear, and Soft Matter Physics, vol. 82, iss. 4, pp. 1-4, 2010.

[Bibtex]`@article{Mangioni2010, abstract = {We introduce a simple model describing a mechanism for transient pattern formation driven by subdominant attractive forces. The patterns can be stabilized if they are confined by means of a particular multiplicative noise into the region where such mechanism is active. The scope of the results appears to transcend the original application context.}, author = {Mangioni, Sergio E. and Deza, Roberto R.}, doi = {10.1103/PhysRevE.82.042101}, file = {:opt/publicaciones/mendeley/Mangioni, Deza - 2010 - Nonequilibrium pattern formation by subdominant attractive forces A simple model and a stabilization strategy by.pdf:pdf}, issn = {15393755}, journal = {Physical Review E - Statistical, Nonlinear, and Soft Matter Physics}, number = {4}, pages = {1--4}, pmid = {21230330}, title = {{Nonequilibrium pattern formation by subdominant attractive forces: A simple model and a stabilization strategy by means of noise}}, volume = {82}, year = {2010} }`

- G. G. Izús, A. D. Sánchez, and R. R. Deza,
**Noise-driven synchronization of a FitzHugh-Nagumo ring with phase-repulsive coupling: A perspective from the system’s nonequilibrium potential**–Physica A: Statistical Mechanics and its Applications, vol. 388, iss. 6, pp. 967-976, 2009.

[Bibtex]`@article{Izus2009, abstract = {We study a one-dimensional array of N autonomous units with excitable FitzHugh-Nagumo dynamics coupled in phase-repulsive way to form a ring, and submitted to a common subthreshold harmonic signal and independent Gaussian white noises with a common intensity $\eta$. By varying $\eta$, two macroscopic regimes are observed. For some value of noise intensity, a transition from the rest state to an activated one-with almost half of the neurons excited forming an "...-activated-inhibited-activated-... " structure along the ring-takes place. For larger values of $\eta$, the inverse transition is also observed, and both states alternate in a synchronized way with the signal. Moreover, measures of activation and coherent behavior become maximal for intermediate values of $\eta$. The origin of these collective effects is explained in terms of the system's nonequilibrium potential. In particular, the levels of noise for activation and synchronization are theoretically estimated. © 2008 Elsevier B.V. All rights reserved.}, author = {Iz\'{u}s, Gonzalo G. and S\'{a}nchez, Alejandro D. and Deza, Roberto R.}, doi = {10.1016/j.physa.2008.11.031}, file = {:opt/publicaciones/mendeley/Iz\'{u}s, S\'{a}nchez, Deza - 2009 - Noise-driven synchronization of a FitzHugh-Nagumo ring with phase-repulsive coupling A perspective from t.pdf:pdf}, issn = {03784371}, journal = {Physica A: Statistical Mechanics and its Applications}, keywords = {Complex systems,Nonequilibrium potential,Synchronization}, number = {6}, pages = {967--976}, publisher = {Elsevier B.V.}, title = {{Noise-driven synchronization of a FitzHugh-Nagumo ring with phase-repulsive coupling: A perspective from the system's nonequilibrium potential}}, url = {http://dx.doi.org/10.1016/j.physa.2008.11.031}, volume = {388}, year = {2009} }`

- S. E. Mangioni, R. R. Deza, and H. S. Wio,
**Coupling-reentrant phase transition, complex hysteretic behavior, and efficiency optimization in coupled phase oscillators submitted to colored flashing potentials**–Physical Review E – Statistical, Nonlinear, and Soft Matter Physics, vol. 66, iss. 5, pp. 1-12, 2002.

[Bibtex]`@article{Mangioni2002, abstract = {A recent mean-field analysis of a model consisting of N nonlinear phase oscillators-under the joint influence of global periodic coupling with strength K0 and of local multiplicative and additive noises-has shown a nonequilibrium phase transition towards a broken-symmetry phase exhibiting noise-induced transport, or "ratchet" behavior. In a previous paper we focused on the relationship between the character of the (mean velocity <Xdot;> vs load force F) hysteresis loop, the number of "homogeneous" mean-field solutions, and the shape of the stationary mean-field probability distribution function (PDF). Here we assume that the multiplicative noises of the model are Ornstein-Uhlenbeck with common strength Q and self-correlation time tau. By resorting to an effective Markovian approximation, we study the tau dependence of the phase boundary, and that of the line signaling the transition from the "interaction-driven regime" to the "noise-driven regime." We also study-for selected representative points of the K0 vs Q phase diagram-the tau dependence of the transport properties induced by coupling and colored multiplicative noise (including the efficiency epsilon of the mechanical rectification process) and that of the above-mentioned PDF.}, author = {Mangioni, S. E. and Deza, R. R. and Wio, H. S.}, doi = {10.1103/PhysRevE.66.051106}, file = {:opt/publicaciones/mendeley/Mangioni, Deza, Wio - 2002 - Coupling-reentrant phase transition, complex hysteretic behavior, and efficiency optimization in coupled ph.pdf:pdf}, issn = {15393755}, journal = {Physical Review E - Statistical, Nonlinear, and Soft Matter Physics}, number = {5}, pages = {1--12}, pmid = {12513466}, title = {{Coupling-reentrant phase transition, complex hysteretic behavior, and efficiency optimization in coupled phase oscillators submitted to colored flashing potentials}}, volume = {66}, year = {2002} }`

- H. S. Wio, S. E. Mangioni, and R. R. Deza, “Disordering effects of colour in a system of coupled Brownian motors: Phase diagram and anomalous to normal hysteresis transition,” in Physica D: Nonlinear Phenomena, 2002, pp. 184-192.

[Bibtex]`@inproceedings{Wio2002, abstract = {A system of periodically coupled nonlinear phase oscillators - submitted to both additive and multiplicative white noises - has been recently shown to exhibit ratchetlike transport, negative zero-bias conductance, and anomalous hysteresis. These features stem from the asymmetry of the stationary probability distribution function, arising through a noise-induced non-equilibrium phase transition which is re-entrant as a function of the multiplicative noise intensity. Using an explicit mean-field approximation we analyse the effect of the multiplicative noises being coloured, finding a contraction of the ordered phase (and a re-entrance as a function of the coupling) on one hand, and a shift of the transition from anomalous to normal hysteresis inside this phase on the other. ?? 2002 Elsevier Science B.V. All rights reserved.}, archivePrefix = {arXiv}, arxivId = {cond-mat/0109455}, author = {Wio, H. S. and Mangioni, S. E. and Deza, R. R.}, booktitle = {Physica D: Nonlinear Phenomena}, doi = {10.1016/S0167-2789(02)00508-0}, eprint = {0109455}, file = {:opt/publicaciones/mendeley/Wio, Mangioni, Deza - 2002 - Disordering effects of colour in a system of coupled Brownian motors Phase diagram and anomalous to normal.pdf:pdf}, issn = {01672789}, keywords = {Anomalous to normal hysteresis,Brownian motors,Noise-induced phase transition}, pages = {184--192}, primaryClass = {cond-mat}, title = {{Disordering effects of colour in a system of coupled Brownian motors: Phase diagram and anomalous to normal hysteresis transition}}, volume = {168-169}, year = {2002} }`

- S. E. Mangioni, R. R. Deza, and H. S. Wio,
**Transition from anomalous to normal hysteresis in a system of coupled Brownian motors: a mean-field approach.**–Physical review. E, Statistical, nonlinear, and soft matter physics, vol. 63, iss. 4 Pt 1, p. 41115, 2001.

[Bibtex]`@article{Mangioni2001, abstract = {We address a recently introduced model describing a system of periodically coupled nonlinear phase oscillators submitted to multiplicative white noises, wherein a ratchetlike transport mechanism arises through a symmetry-breaking noise-induced nonequilibrium phase transition. Numerical simulations of this system reveal amazing novel features such as negative zero-bias conductance and anomalous hysteresis, explained by performing a strong-coupling analysis in the thermodynamic limit. Using an explicit mean-field approximation, we explore the whole ordered phase finding a transition from anomalous to normal hysteresis inside this phase, estimating its locus, and identifying (within this scheme) a mechanism whereby it takes place.}, archivePrefix = {arXiv}, arxivId = {cond-mat/0012409}, author = {Mangioni, S. E. and Deza, R. R. and Wio, H. S.}, doi = {10.1103/PhysRevE.63.041115}, eprint = {0012409}, file = {:opt/publicaciones/mendeley/Mangioni, Deza, Wio - 2001 - Transition from anomalous to normal hysteresis in a system of coupled Brownian motors a mean-field approach.pdf:pdf}, issn = {1063-651X}, journal = {Physical review. E, Statistical, nonlinear, and soft matter physics}, number = {4 Pt 1}, pages = {041115}, pmid = {11308827}, primaryClass = {cond-mat}, title = {{Transition from anomalous to normal hysteresis in a system of coupled Brownian motors: a mean-field approach.}}, volume = {63}, year = {2001} }`

- S. E. Mangioni, R. R. Deza, R. Toral, and H. S. Wio,
**Nonequilibrium phase transitions induced by multiplicative noise: effects of self-correlation**–Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, vol. 61, iss. 1, pp. 223-32, 2000.

[Bibtex]`@article{Mangioni2000, abstract = {A recently introduced lattice model, describing an extended system which exhibits a reentrant (symmetry-breaking, second-order) noise-induced nonequilibrium phase transition, is studied under the assumption that the multiplicative noise leading to the transition is colored. Within an effective Markovian approximation and a mean-field scheme it is found that when the self-correlation time tau of the noise is different from zero, the transition is also reentrant with respect to the spatial coupling D. In other words, at variance with what one expects for equilibrium phase transitions, a large enough value of D favors disorder. Moreover, except for a small region in the parameter subspace determined by the noise intensity sigma and D, an increase in tau usually prevents the formation of an ordered state. These effects are supported by numerical simulations.}, author = {Mangioni, Sergio E. and Deza, Roberto R. and Toral, R. and Wio, Horacio S.}, file = {:opt/publicaciones/mendeley/Mangioni et al. - 2000 - Nonequilibrium phase transitions induced by multiplicative noise effects of self-correlation.pdf:pdf}, issn = {1063-651X}, journal = {Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics}, number = {1}, pages = {223--32}, pmid = {11046259}, title = {{Nonequilibrium phase transitions induced by multiplicative noise: effects of self-correlation}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/11046259}, volume = {61}, year = {2000} }`

- S. E. Mangioni, R. R. Deza, H. S. Wio, and R. Toral,
**Disordering effects of color in nonequilibrium phase transitions induced by multiplicative noise**-, iss. September, p. 4, 1997.

[Bibtex]`@article{Mangioni1997, abstract = {The model introduced by Van den Broeck, Parrondo and Toral [Phys. Rev. Lett.73, 3395 (1994)] -- leading to a second-order-like noise-induced nonequilibrium phase transition which shows reentrance as a function of the (multiplicative) noise intensity \$\backslash sigma\$-- is investigated beyond the white-noise assumption. Through a Markovian approximation and within a mean-field treatment it is found that -- in striking contrast with the usual behavior for equilibrium phase transitions -- for noise self-correlation time \$\backslash tau>0\$, the stable phase for (diffusive) spatial coupling \$D\backslash to\backslash infty\$ is always the disordered one. Another surprising result is that a large noise "memory" also tends to destroy order. These results are supported by numerical simulations.}, archivePrefix = {arXiv}, arxivId = {cond-mat/9707308}, author = {Mangioni, S. E. and Deza, R. R. and Wio, H. S. and Toral, R.}, doi = {10.1103/PhysRevLett.79.2389}, eprint = {9707308}, file = {:opt/publicaciones/mendeley/Mangioni et al. - 1997 - Disordering effects of color in nonequilibrium phase transitions induced by multiplicative noise.pdf:pdf}, isbn = {0031-9007}, issn = {0031-9007}, number = {September}, pages = {4}, primaryClass = {cond-mat}, title = {{Disordering effects of color in nonequilibrium phase transitions induced by multiplicative noise}}, url = {http://arxiv.org/abs/cond-mat/9707308}, year = {1997} }`

E-MAIL: asanchez@ifimar-conicet.gob.ar

TEL: **+54 9 223 475-5507 (int 39)**

**Investigador Adjunto (CONICET)**

E-MAIL: megevand@ifimar-conicet.gob.ar

TEL: **+54 9 223 475-5507 (int 20)**

**Investigador Adjunto (CONICET)**

E-MAIL: claroca@ifimar-conicet.gob.ar

TEL: **+54 9 223 475-5507 (int 35)**

**Investigador Asistente (CONICET)**

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My about is all about complex physical and biological systems.

In this context I deal mainly with two topics:

- Analysis of interface growth models and
- Modeling the dynamics of collective movements within bacterial colonies.

E-MAIL: gzarza@ifimar-conicet.gob.ar

TEL: **+54 9 223 475-5507 (int 41)**

**Ingeniero Electrónico – CPA Profesional (CONICET)**