A previous attempt by a different group of engineers used pulsed electromagnets.This, though, required both high pressure, which is expensive to create, and the electromagnets themselves, which are costly to buy and costly to run.Dr Vetrovec intends to perform his version of the trick at atmospheric pressure, and using permanent magnets.Both of these modifications greatly reduce power consumption. In fact, the device's only moving part is the blower which pushes air through it.The magic extra ingredient Aqwest brings to the party is an array of structures called microchannels.These are tubes less than a millimetre in diameter that are intended to carry liquids or gases.Crucially, their narrow bores ensure the laminar flow of any fluid passing through them.Translated from physics-speak, this means they cause no turbulence, and therefore no mixing of their contents.That allows them to act as gas separators in the firm's device.On the face of things, the initial results do not look that impressive.Prototypes yield a concentration increase of around 0.1% per passage, though Dr Vetrovec thinks his team can raise this to 0.4%.The key, though, is the repetition. Like the tale about a vizier who asked his king, as a reward for some service,
