The disorder results from overproduction of collagen, a naturally occurring protein found in the skin. It is unknown what causes this overproduction of collagen to occur but the immune system is believed to play a significant role. Morphea is not contagious or passed down in families.
A typical US household voltage is 120/240 V, 60 hz, single phase. There is a tolerance and the actual measured voltage is rarely exactly 120 volts. A common reading at my house is 117 volts. Industrial motors are made and rated in multiples of 115V (115, 230, 460, and 550Vac) for use on line voltages in multiples of 120 V (120, 240, 480, and 600 Vac).
Dual voltage appliances are those appliances that are designed to operate safely on both 110 volt and 220 volt electricity. Some items make the switch automatically, but most dual voltage appliances have a switch, knob, or other mechanism that must be adjusted from the 110 setting to the 220 setting.