The invention discloses radio frequency zero crossing signal generators for optical disc drives, comprising a controllable low pass filter, a comparator, and a control circuit. The portable potty has four adjustable legs and a removable bag holder ring which holds a disposable bag for one-time use. An electromagnetic boom associated with an oil spill cleanup apparatus are used to create a magnetic field proximate to the electromagnetic boom. Each feature has an assigned bit in the bit mask. The one or more glass surfaces can be part of outer member assemblies that can be secured to other portions of the electronic device housing. argon ions, at a dose of about 1\xd71013 atomscm2 to about 9\xd71015 atomscm2 having an implantation energy of about 10 KeV to about 50 KeV.