Abstract: An air purification system for purifying atmospheric air has an ionization chamber that includes a needle arrangement. The needles create a dense and strong electric field when a high voltage is passed to them by the effect of dual charge ionization due to which the suspended particles in the polluted air get clumped together and fall. The second invention is an air monitoring system facilitating a two-way communication with external information sources. It contains gas sensors comprising of an ambient noise sensor, temperature and humidity sensor, and sensors to measure the amount of oxides of nitrogen, Sulphur, carbon and size of suspended particles in the air. The third invention is a theft protection module for the safe keeping of an air purification system.

Abstract: An apparatus, computer software, and a method of determining position inside a building comprising selecting on a PDA at least two walls of a room in a digitized map of a building or a portion of a building, pointing and firing a laser rangefinder at corresponding physical walls, transmitting collected range information to the PDA, and computing on the PDA a position of the laser rangefinder within the room.

Abstract: An alignment apparatus for aligning x-ray images with a predetermined set of axes comprises means defining the axes in the form of a support arrangement which supports, at predetermined positions in space, located in at least two predetermined planes, a plurality of elements which are opaque to ex-radiation. An apparatus is also described for aligning an end effector comprising two spaced guide frames each having two parallel guide members with a carriage for movement along each of the guide members, the carriages being inter-connected by cross members, further carriages being mounted on the cross members, the further carriages supporting the end effector for guide means.