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).
What is Alternating Current. Alternating current has a constant voltage, but constantly changes position between positive and negative polarities, producing a wave when represented visually. Electric current is transmitted around the country in the form of alternating current. 120 volts and 60 cycles (position changes between polarities positive to negative to positive) per second (60 Hz) alternating current is what is the most common power source that is supplied to United States residential homes.