In this regard, we also wish to note that there have been sharp declines in seagrasses of some polluted coastal regions ( 16, 17) that may be associated with surface contamination, which, even when the concentration of contaminants is very small, can influence the porous structure of pollen rafts. 14 and 15 that the formation of porous pollen rafts increases the probability of pollination, because the surface area of the raft is much greater than that of a single pollen grain. After this initial dispersion, the pollen particles (usually, form a single anther) cluster to form a pollen raft. Cox and Knox ( 14) did not give a reason for the initial dispersion of pollen, but in our experiments, it disperses like glass particles of the same approximate size. For example, an important first step in the formation of porous pollen structures called “pollen rafts” is the initial dispersion of pollen occurring after it comes in contact with the water surface ( 14). The sudden dispersion of particles may also have an important role in some biological and chemical processes involving fluid-fluid interfaces. In our experiments, the frequency of oscillation for a ≈1.2-mm-sized mustard seed was ≈83 Hz. Such underdamped oscillations of a particle were observed in experiments, as well as in direct numerical simulations (DNS) where particles are moved according to the fundamental equations of motion of fluids and solid particles without the use of models ( 7). This behavior of the particle is similar to that of underdamped spring-dashpot systems which oscillate about the equilibrium height a few times before coming to rest ( Figs. Hence, after moving down some additional distance, the particle reverses its direction. When the particle moves below its equilibrium height, the capillary force reverses direction and acts in the same direction as the drag. Viscous drag causes the particle to slow down, but for a small particle, the drag is not large enough to stop the particle, because its momentum carries it below the equilibrium height. High dispersion is associated with low precision.The motion of the particle is dominated by inertia, and may overshoot equilibrium. In some processes, like manufacturing or measurement, low dispersion is associated with high precision. Quartiles: Numbers that split the data into four quarters (first, second, third, and fourth quartiles).Median absolute deviation (MAD): the median of the absolute deviations from a data set’s median.Mean difference or difference in means: measures the absolute difference between the mean value in two different groups in clinical trials.range : the difference between the smallest and largest number in a set of data. ![]()
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