A disposable diaper includes a basic absorbent batt structure and a supplementary absorbent batt structure placed thereon. Specifically, dummy patches that are not measured are printed on the periphery of measured patches. The outcome of the second group game is determined first, but is only applied if the first game is a winner. The oxy-nitride layer behaves like a barrier, blocking the inflow of the plasma-induced charges. Raffinate obtained may be treated with oxalic acid, the precipitate dissolved in hydrochloric acid and subjected to solvent extraction for rare earth elements or the raffinate may be subjected to solvent extraction for removal of rare earth elements and then stripped with hydrochloric acid.