Abstract: A vacuum cleaning appliance includes a vacuum cleaning head having a suction opening, the head having a first state and a second state, a fan unit for drawing an air flow through the suction opening, and a control assembly for controlling the state of the head.

Abstract: The invention relates to a sensor system for the identification and/or measurement of levels of target species in aqueous solution, and in particular for the identification and/or determination of levels of contaminant species such as nutrient species in the aqueous phase.

Abstract: A gas turbine engine blade tip clearance control system and method is described. An annular housing is formed about an engine casing to which an annular shroud segment assembly is secured and closely spaced about blade tips of a stage of blades. The annular housing forms an air passage means communicating with the casing for directing a cooling air stream to the casing. A thermally operable passive ring valve is formed by two overlapped metal ring segments having a dissimilar coefficient of thermal expansion selected whereby to produce a radial gap between the ring segments when the valve temperature reaches a predetermined value. The radial gap admits a cooling air flow into the housing for cooling the casing and its associated shroud segment assembly to control radial growth and thereby prevent blade tip pinching.

Abstract: A game in which an object, such as a ball, is maneuvered upon a meandering path upwardly slanting to a goal. The ball is directed along the path by a manipulating device, such as a rod. The ball is free to move laterally along an edge of the rod under the force of gravity as the rod is tilted from the horizontal, and the ball may be moved linearly (advanced or retracted) by sliding the rod forward or backward along the path.