We propose a reaction-diffusion extension of a two species ecotoxicological model with time-delays proposed by Chattopadhyay et al (1997). Each species has the capacity to produce a substance toxic to its competitor, and a distributed time-delay is incorporated to model lags in the production of toxin. Additionally, nonlocal spatial effects are present because of the combination of delay and di...

We study numerical approximations of a recently proposed phase field model for the vesicle membrane deformations governed by the variation of the elastic bending energy. Both the spatial discretization for the equilibrium problem with given volume and surface area constraints and the time discretization of a dynamic problem via gradient flow are considered. Convergence results of the numerical ...

We consider a model of platform adaptation in spatial voting focussing on the effect of abstention on the stability of the mean voter equilibrium. Two distinct approaches for modeling abstention are explored: (1) voters abstain if party platforms are too similar to each other and (2) voters abstain if both party platforms are far away from their ideal points.

Relaxation of the thermal Casimir or van der Waals force (the high temperature limit of the Casimir force) for a model dielectric medium is investigated. We start with a model of interacting polarization fields with a dynamics that leads to a frequency dependent dielectric constant of the Debye form. In the static limit, the usual zero frequency Matsubara mode component of the Casimir force is ...

There is a growing awareness in recent years that the interdependencies among the civil infrastructure systems have significant economic, security and engineering implications that may influence their resiliency, efficiency and effectiveness. To capture the various types of infrastructure interdependencies and incorporate them into decision-making processes in various application domains, Zhang...

In this paper we analyze the spatial dynamics of a class of systems in which many agents continually reassess decisions of where to locate in a given region. Each agent gives rise to an externality whose impact diffuses to other agents. Thus every agent experiences a composite of externalities emitted by other agents. We term this composite a spatial externality. On the one hand, the level of t...

We study the strategic behavior of voters in a spatial model of proportional representation, in which the policy space is multidimensional. Our main finding is that in large electorate, under some assumptions on voters’ preferences, voters essentially vote, in any equilibrium, only for the extreme parties.

By using differential equations, evolutionary game theory shows that most of the games of competition for resources have equilibrium strategies named Evolutionary Stable. Although this approach can deduce these points, it is not possible to say how or whether a population will reach such equilibrium. We present an evolutionary agent-based model where individuals compete for space using mixed st...

In this study, nano-TiO2 was employed for the adsorption of chloroform from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. The effects of pH, initial chloroform concentration and nano-TiO2 dosage were also investigated. Optimal conditions for chloroform removal by nano-TiO2 have been then identified. Results of equilibrium experiments showed that the...