Abstract: A camera is set up to survey an area of water, recording images of the whole area, or scanning it section by section. Each image is compared with a previous one of the same area, captured under the same ambient conditions in the past and selected from a library holding images of the area under many different ambient condition, all without pollution or contaminants affecting the surface signature. Alternatively, the comparison is made with a recent image, taken as part of a sequence. Image analysis software can determine if there are differences between the images indicative of pollution, such as by an oil slick, ad an alarm can then be raised to prompt more detailed investigation. The system can have applications to other environments where changes may be determined or at least need to be monitored.

Abstract: A spray generator has a gas duct (1, 6, 10, 14, 16, 21) from which issues a stream of gas in various configurations according to the shape of the delivery end. Liquid is directed by nozzles (3, 11) or other means (13, 18, 22) transversely into the gas stream, although it may have a directional component going with that stream and/or a component to generate swirl. The relative speeds and amounts of gas and liquid cause the liquid to break up into droplets (9, 24) which form discrete clusters (5, 8) in a compact spray pattern. Secondary gas streams (17, 23) can be applied further to shape the spray pattern.

Abstract: A spray generator has a gas duct (1, 6, 10, 14, 16, 21) from which issues a stream of gas in various configurations according to the shape of the delivery end. Liquid is directed by nozzles (3, 11) or other means (13, 18, 22) transversely into the gas stream, although it may have a directional component going with that stream and/or a component to generate swirl. The relative speeds and amounts of gas and liquid cause the liquid to break up into droplets (9, 24) which form discrete clusters (5, 8) in a compact spray pattern. Secondary gas streams (17, 23) can be applied further to shape the spray pattern.