Bacterial activity hinders particle sedimentation

Dynamic stereo microscopy for studying particle sedimentation.

We demonstrate a new method for measuring the sedimentation of a single colloidal bead by using a combination of optical tweezers and a stereo microscope based on a spatial light modulator. We use optical tweezers to raise a micron-sized silica bead to a fixed height and then release it to observe its 3D motion while it sediments under gravity. This experimental procedure provides two independe...

Non-equilibrium pattern selection in particle sedimentation

In this paper, we explain some well known experimental observations in fluid solid interaction from a thermodynamic perspective. In particular we use the extremum of the rate of entropy production to establish the stability of specific patterns observed in single and multiparticle sedimentation in an infinite fluid and the sedimentation of spheres in the presence of walls. While these phenomena...

Hinders Development of Acquired Immunity Successful Treatment of Bacterial Infection

Sedimentation from particle-bearing plumes in a stratified ambient

Laboratory experiments are performed to examine the sedimentation of particles that initially rise in a plume, then spread radially and settle in uniformly stratified fluid. Using light attenuation, the depth of the sediment bed is measured nonintrusively as a function of radius from the center of the plume. To gain some insight into these dynamics, an idealized model is developed by adapting w...

Flow patterns in the sedimentation of an elliptical particle

ZHENHUA XIA, KEVIN W. CONNINGTON, SAIKIRAN RAPAKA, PENGTAO YUE , JAMES J. FENG AND SHIYI CHEN† State Key Laboratory for Turbulence & Complex Systems, CAPT and CCST, College of Engineering, Peking University, Beijing, China Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA Department of Chemical and Biological Engineering and Department of Mathematics, ...