Reversible Transient Nucleation in Ionic Solutions as the Precursor of Ion Crystallization

Molecular dynamics simulations for aqueous sodium chloride solutions were carried out at various concentrations. Supplementary to the Debye-H\"uckel theory, reversible transient nucleation of ions was observed even in dilute solutions. The average size of formed ion clusters and the lifetime of ion pairs increase with concentration until the saturation point, when ion clusters become stable and individual ions adjust their positions to form ordered lattice structures, leading to irreversible ion crystallization, which is beyond the description of the classical nucleation theory.Comment: 4 pages, 5 figures, and 46 reference

Series expansion studies of random sequential adsorption with diffusional relaxation

We obtain long series (28 terms or more) for the coverage (occupation fraction) $\theta$, in powers of time $t$ for two models of random sequential adsorption with diffusional relaxation using an efficient algorithm developed by the authors. Three different kinds of analyses of the series are performed for a wide range of $\gamma$, the rate of diffusion of the adsorbed particles, to investigate the power law approach of $\theta$ at large times. We find that the primitive series expansions in time $t$ for $\theta$ capture rich short and intermediate time kinetics of the systems very well. However, we see that the series are still not long enough to extract the kinetics at large times for general $\gamma$. We have performed extensive computer simulations employing an efficient event-driven algorithm to confirm the $t^{-1/2}$ saturation approach of $\theta$ at large times for both models, as well as to investigate the short and intermediate time behaviors of the systems.Comment: 35 pages. revtex. 16 eps figures. Series expansion coefficients are attached at the end of the soure/LaTex file (named diff.tex). uses fleqn.st

Partial Deposit Insurance and Moral Hazard in Banking

Abstract: Countries with deposit insurances differ significantly on how much protection their insurance provides. We study the optimal coverage limit in a model of deposit insurance with capital requirements and risk sensitive premia to prevent moral hazard. Depositors have incentives to monitor the bank’s risk taking behavior, thus threatening banks with withdrawals of deposits if necessary. We find that either banking regulations or market discipline is insufficient to reduce bank’s risk. In addition, our numerical example explains the differences in coverage cross countries which agrees with empirical evidence. We show that low income countries provide more generous insurance protection than higher income countries.Depositor’s monitoring; moral hazard; optimal coverage, partial deposit insurance.