Abstract: Apparatus for facilitating the removal of material deposited at the bottom (6) of a volume of liquid (7) the apparatus including a suction pump assembly (2) associated with a suction head/nozzle (9) mounted to a user handling element (4) and means (24) drivable by the motor for displacing sucked-in water and (8) to a delivery location (11), in such manner that when used in use the pump assembly (2) can be submerged, and wherein the suction pump assembly (2) includes means (40) for enabling controlled air escape from the vicinity of the means (24) for displacing air from of the pump assembly the arrangement being such as to prevent air blockage of and material flow through the pump following raising of the latter of water.

Abstract: Apparatus for facilitating the removal of material deposited at the bottom (6) of a volume of liquid (7) the apparatus including a suction pump assembly (2) associated with a suction head/nozzle (9) mounted to a user handling element (4) and means (24) drivable by the motor for displacing sucked-in water and (8) to a delivery location (11), in such manner that when used in use the pump assembly (2) can be submerged, and wherein the suction pump assembly (2) includes means (40) for enabling controlled air escape from the vicinity of the means (24) for displacing air from of the pump assembly the arrangement being such as to prevent air blockage of and material flow through the pump following raising of the latter of water.

Abstract: A fluorescent lamp produces light having color coordinates within an ellipse (A) about 22 standard deviation of color matching around the color coordinates (b)x=0.344 y=0.302. The luminescent layer of the lamp includes a mixture of: magnesium fluorogermanate activated by manganese as red emitter; calcium halophosphate as white emitter; and a blue emitter preferably strontium pyrophosphate activated by divalent tin. The layer may alternatively be a mixture of red emitting magnesium fluorogermanate and blue emitting barium titanium pyrophosphate. Other blue emitters are also described.