A signal detector includes a detector to generate raw decisions based on a read back signal. At the top of the de-ethanizer the vapor of the column distillate is treated directly in an acetylene hydrogenation reactor, the effluent containing virtually no acetylene being separated by a distillation column called a de-methanizer, into an ethylene- and ethane-enriched tail product, while the head product is recycled by compression or treated for subsequent recovery of ethylene. To erase the memory cell, the first voltage is applied on a first side of the floating gate and th second voltage is on a second, opposite side of the floating gate. The coating is harder and more abrasive than the mating surfaces of the planet gear teeth. A plurality of reconstruction parities is computed. The storage electrode part includes at least one side having an angle of about forty degrees to about fifty degrees with respect to the alignment direction.