Foam Generation,Propagation and Stability in Porous Medium

Transport in Porous Media - There have been several foam field applications in recent years. Foam treatments targeting gas mobility control in injectors as well as gas blocking in production wells...     

Amphiphilic Lipopeptide Microparticles as Contrast Agents for Medical Ultrasound Imaging

In this study we investigated the utility of complementary amphiphilic lipopeptides as a new membrane formulation suitable for the preparation of gas‐filled microbubbles. Through primarily ion pairing and hydrophobic interactions we rationalized that the stacking of synthetic lipopeptides into the surface of microbubbles would make bubble suspensions useful as ultrasound contrast agents. By mixing charged lipopeptides in propylene glycol/glycerol solutions in the presence of a perfluorocarbon gas followed by vigorous shaking, microbubble suspensions were formed in good yield with a size distribution spanning the range 1–7 × 10^?6 m. The microbubbles were studied in an in vivo model and provided imaging efficacy comparable with conventional ultrasound contrast agents.

Crude sample (before flotation) of Formulation A analyzed at ×40 magnification. The solid bar indicates 10 × 10^?6 m.     

Slip-Flow over Lubricated Surfaces

Slip-flow boundary conditions have been used in a direct numerical simulation of incompressible turbulent flow in a plane lubricated channel to mimic the unsteady dynamics of the thin lubricating films present at both channel walls. The results are compared with data from a full simulation, in which also the flow inside the lubrication layers was resolved. By replacing the lubrication layers with the slip-flow conditions, both turbulence statistics and coherent near-wall structures in the bulk-fluid are surprisingly well reproduced. In this approach the need to resolve the flow within the lubricating films is eliminated and the computational efforts are therefore reduced.