In PWRs - a different LWR system - control rods are withdrawn from the core, and the control is acheived with soluble B-10 in the coolant (which is buffered with LiOH) to maintain a pH above 6.9 or perhaps closer to 7.1 - 7.4 for purposes of minimizing the accumulation of crud (metal corrosion products) on the fuel.
Rhetorical patterns have an additional function of helping writers to organize information in ways their readers can understand easily (425). Another term for these patterns is topoi (commonplaces). Many of these topoi are useful in numerous situations.
Quick Answer. In graphic design, a repeat pattern is a software-generated pattern that can be tiled and does not repeat or overlap itself. Repeat patterns can be generated in Illustrator or Photoshop. Repeat patterns can be geometric designs, fractal simulations or simple seamless graphics.