The frequency components of the groove wobbles of disks are extracted from push-pull signals SPP by first and second filters in a wobble detecting section. A protective layer is then formed on the patterned epitaxy layer, exposing a top surface of the pier structure. 916 gcm3, the mVLDPE polymer preferably being linear and without long chain branching, a polypropylene homopolymer, random copolymer, or impact copolymer, and optionally flame retardant additives. 9 cc liquidsecond at an 80% absorbent composite saturation level and a liquid lock-up fraction of at least about 0.