where v i-- velocity at point of gypsum block attachment (i) on the horizontal
axis of the bar, d--diameter (cm) of the circle inscribed by the
point i as the bar rotated, and t-- time for 1 revolution (s). It was assumed
that the velocity of the blocks was equal to the velocity of water moving
over the surface of the blocks.
Pond circulation study
This study was conducted in four, 0.04-ha earthen ponds located at
the Fisheries Research Unit of the Alabama Agricultural Experiment
Station, Auburn University, Alabama. Bottom contours for a representative
pond are shown in Fig. 3. The average depth of the ponds was 0"90
m and maximum depths were 1.6 m. One pond was unaerated, and the
others were aerated with a 0.5-hp paddle wheel aerator, a 0.33-hp vertical
pump aerator, and a 0.75-hp vertical pump aerator, respectively. In
each pond, 2-m-long wooden stakes were driven into the pond bottom in