While electric hybrid vehicles are becoming increasingly popular in the US, the government鈥檚 Environmental Protection Agency thinks they are the wrong type. Most drivers are buying hybrids that work using a 鈥減arallel鈥� system. In them the wheels are driven by a battery-powered electric motor, and a conventional fuel-burning engine takes over when the battery charge falls too low. The EPA thinks a 鈥渟eries鈥� system is better, and is patenting a control system for a hybrid in which the wheels are driven by the electric motor powered by a battery that the fuel engine keeps charged up. The trick is to smoothly adjust the running of the fuel engine depending on the level of charge in the battery so that it never goes flat (WO application 2005/032875).
Advertisement
Repair crews often have to dig up the road to find out whether a leak in a mains water pipe is serious. British company Metrika of Badminton, Gloucestershire, says there is a simpler way. By clamping an accelerometer to the ground over a damp patch, an engineer can record the vibrations caused by the water flow. Because the strength of the vibration is directly proportional to the rate at which water is escaping, this reveals the severity of the leak. Measurements are taken in 1-second bursts for 30 seconds to eliminate traffic vibration (GB 2406654).
Banks and passport agencies should dope notes and documents with rare earth elements to prevent forgeries. So says Australian company Securency of Craigieburn, Victoria, which is patenting the idea of blending ytterbium and thulium into a thin film of polypropylene, sandwiched inside a document or note. These elements absorb infrared light and re-radiate it as visible light, so the documents will glow when scanned by a red laser.
Each element could be mixed in secret ratios to emit telltale hues that could be checked by a light sensor (WO 2005/032831).
