33 research outputs found

    Monte Carlo Simulation of Age-Dependent Host-Parasite Relations

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    The death of a biological population is an extreme event which we investigate here for a host-parasitoid system. Our simulations using the Penna ageing model show how biological evolution can ``teach'' the parasitoids to avoid extinction by waiting for the right age of the host. We also show the dependence of extinction time on the population size.Comment: 8 pages including 6 figure

    Social Percolation and the Influence of Mass Media

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    Mass media shift the percolative phase transition observed in the marketing model of Solomon and Weisbuch.Comment: 6 pages including 4 figure

    Insight into Electric field-induced rupture mechanism of water-in-toluene emulsion films from a model system

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    This paper presents a model, which we have designed to get insight into the development of electro- induced instability of a thin toluene emulsion film in contact with the saline aqueous phase. Molecular dynamics (MD) simulations demonstrate the role of charge accumulation in the toluene-film rupture induced by a DC electric field. Two ensembles¿NVT and NPT ¿are used to determine the critical value of the external field at which the film ruptures, the charge distribution and capacitance of the thin film, number densities, and the film structure. The rupture mechanism as seen from this model is the following: in both NVT and NPT ensembles, condenser plates, where the charge density is maximal, are situated at the very border between the bulk aqueous (water) phase and the mixed layer. No ion penetration is observed within the toluene core, thus leaving all the distribution of charges within the mixed zone and the bulk phase that could be attributed to the formation of hydration shells. When the critical electric field is reached within a certain time after the field application, electric discharge occurs indicating the beginning of the rupturing process. The MD simulations indicate that the NPT ensemble predicts a value of the critical field that is closer to the experimental finding. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.498316
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