Origin of line tension for a Lennard-Jones nanodroplet

The existence and origin of line tension has remained controversial in literature. To address this issue we compute the shape of Lennard-Jones nanodrops using molecular dynamics and compare them to density functional theory in the approximation of the sharp kink interface. We show that the deviation from Young's law is very small and would correspond to a typical line tension length scale (defined as line tension divided by surface tension) similar to the molecular size and decreasing with Young's angle. We propose an alternative interpretation based on the geometry of the interface at the molecular scale

Multiple Model Predictive Control on a drainage canal system

Model Predictive Control has been implemented on a large drainage canal system in the Netherlands. This water system can be represented as a reservoir with uncertain inflow due to rainfall runoff and a water level that has to be kept within a certain range by a control flow that is limited in capacity. Tests demonstrate that Model Predictive Control outperforms feedback and feedforward controls. To deal with uncertainty in the expected inflow, Multiple Model Predictive Control (MMPC) is proposed. This controller minimizes an objective function in which the risk of damage is used by applying different scenarios to multiple identical models

Formation of surface nanobubbles and universality of their contact angles: A molecular dynamics approach

We study surface nanobubbles using molecular dynamics simulation of ternary (gas, liquid, solid) systems of Lennard-Jones fluids. They form for sufficiently low gas solubility in the liquid, i.e., for large relative gas concentration. For strong enough gas-solid attraction, the surface nanobubble is sitting on a gas layer, which forms in between the liquid and the solid. This gas layer is the reason for the universality of the contact angle, which we calculate from the microscopic parameters. Under the present equilibrium conditions the nanobubbles dissolve within less of a microsecond, consistent with the view that the experimentally found nanobubbles are stabilized by a nonequilibrium mechanism.Comment: 5p,4

Liquid drops attract or repel by the inverted Cheerios effect

European Union Grant CIG 618335. S.K. acknowledges financial support from NWO through VIDI Grant 11304. A.P. and J.H.S. acknowledge financial support from European Research Council Consolidator Grant 616918

Brazil

Biological and Soft Matter Physic