The present invention is directed to, among other things, a grinding and impeller clip for attaching to a wheel assembly mounted for rotational motion within a grinding chamber of a coal pulverizer, wherein the clip has an arcuate cross sectional profile and a protective layer on its upper surface. The wireless communicator can use carrier-to-interference ratio measurements and sector load information for each of its Active Set sectors ) to determine the best serving sector. The methods of the current invention contact the subterranean formation with downhole maleic acid solutions for a period of time sufficient to restore fluid permeability to the formation. Thereby, this invention is able to present coated particles wherein each surface of the first particles is uniformly coated with the second particles that are more microscopic than the first particles.