In PWRs - a different LWR system - control rods are withdrawn from the core, and the control is acheived with soluble B-10 in the coolant (which is buffered with LiOH) to maintain a pH above 6.9 or perhaps closer to 7.1 -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.
Definition of a Rhetorical Triangle. Aristotle wrote one of the first great treatises on rhetoric, aptly titled, Rhetoric. This treatise was written in the 4th century BCE and it outlines the three main rhetorical appeals: logos, pathos, and ethos. These three persuasive strategies make up the rhetorical triangle.