Sinking, gravitational

The problem of estimating the diffusion layer thickness therefore reduces to that of estimating u and We have considered three possible mechanisms for the movement of phytoplankton through the water gravitational sinking, convective water movements and the swimming of flagellates. 

Gravitational sinking. Phytoplankton cells are generally denser than the surrounding sea water and therefore sink unless kept in suspension by convective water movements (35). ( for... 

Figure 2. Histogram of estimated values of (8)av for gravitational sinking of phytoplankton cells. Estimates obtained from data given for live cells by Smayda...

This equation gives Sav values in much the same range as gravitational sinking and open water turbulence (Figure 5),... 

Note When precipitation occurs in sol-gel processing, sol particles have aggregated to a size where gravitational forces cause them to sink or float. Generally, aggregation arises from a change in the sol that reduces the interparticle repulsion. 

Although there is no need for a certain size cylinder, the cylinder should have a sufficient height to clearly detect the visible boundary that forms as droplets rise to the top or sink to the bottom under the influence of the gravitational field. Throughout the experimental series, the type of glass cylinder used should be consistent. 

Figure 7.4 Small spherical particle in a liquid-gas interface for which gravitation is negligible (left). The shape of the interface remains unchanged by the presence of the particle. For larger particles (right) the liquid interface is deformed and a net capillary force stabilizes the particle and prevents it from sinking.

The sedimentation of particles in the water column represents an important mechanism for sediment transport and is most fundamentally controlled by gravitational setting. Gravitational forces, which act in a downward direction, are also opposed by the viscous resistance of water in an upward direction. The sinking speed for spherical, slow sinking, single particles is described by Stoke s law (Allen, 1985) ... 

There are three major sinks that act to remove particles from the atmosphere diffusion (Brownian motion), wet deposition, and gravitational settling. The relative importance of each mechanism depends primarily upon particle size (Seinfeld and Pandis 1998 Kreidenweis et al. 1999 Friedlander 2000). As shown in Figure 4, diffusion is the... 

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