Carbon Cycle Chemical Reactions Involved: Photosynthesis: Air and water molecules and the energy from the sun to produce a simple sugar such as glucose and oxygen molecules as a by product. During photosynthesis plants use carbon dioxide and produce oxygen.
Similar to shore power for ships, a ground power unit (GPU) may be used to supply electric power for an aircraft on the ground, to sustain interior lighting, ventilation and other requirements before starting of the main engines or the aircraft auxiliary power unit (APU).
Auxiliary power. An active alternative to engine idling. Idling a tractor engine for in-cab comfort or to ensure cold starts is very costly. It increases fuel cost, engine hours, engine maintenance, and service cost. With the Carrier auxiliary power unit (APU), you can turn off your engine, be comfortable, and turn down your operating costs.