Ultrasound technicians may expect to perform some of their work in rooms with low lighting. They can expect to be on their feet for a majority of their work time, and must be able to do some lifting or turning of patients who require assistance.
semiconductor diode A diode made of semiconductor components, usually silicon. The cathode, which is negatively charged and has an excess of electrons, is placed adjacent to the anode, which has an inherently positive charge, carrying an excess of holes. At this junction a depletion region forms, with neither holes nor electrons.
A very basic introduction to how a light-emitting diode works. In the simplest terms, a light-emitting diode (LED) is a semiconductor device that emits light when an electric current is passed through it. Light is produced when the particles that carry the current (known as electrons and holes) combine together within the semiconductor material. Since light is generated within the solid semiconductor material, LEDs are described as solid-state devices.