Instead, all these devices produce light by the transition of electrons from one energy level to another.

They said that over a period of weeks their device produced more energy than it consumed.

How the device produces a lasting effect is being investigated.

Built-in devices can be used but may not produce the desired quality.

The company says its device could produce 60 to 90 watt-hours a pound.

The device has produced much more than a mechanical effect.

Even more important is how different devices produce white and black.

Indeed, the new device does not even produce enough energy to warm the hand.

The devices do not produce O8 because there is no such animal.

Every nuclear device produces gamma rays, which pass through almost everything but lead.