Abstract: A gas turbine engine is provided comprising a compressor with an insulated cooling circuit. The compressor comprises a compressor casing having a compression chamber and at least one stator and at least one rotor disposed in the compression chamber, the at least one stator comprising a stator body having a plurality of tubes for transporting cooling air through passages in the stator body into the compression chamber. The plurality of tubes are surrounded by an air gap for insulating the tubes from the stator body.

Abstract: An intumescent coating in the form of an initially liquid coating which cures to a solid and adheres to a substrate. The coating includes a flexible thermosetting epoxy, such as diglycidyl ether of bisphenol-A (DGEBA), with an aliphatic amine curing agent, expandable graphite flakes with reagent chemicals that react upon heating and decompose into gaseous products, and fumed silica. In the presence of heat or flame, an intumescent layer develops at the coating surface, insulating the substrate. The coating is found to add intumescent characteristics which provide heat resistant and fire retardant qualities.

Abstract: A teaching aid comprises a frame (1), a plurality of elongate rods (2) mounted horizontally in the frame and spaced vertically from each other and a plurality of polyhedral blocks (3) rotatably mounted on each rod. Means are provided to releasably hold each block (3) in at least three discrete rotary positions on its respective rod (2).

Abstract: Methods are disclosed for producing solid phase cloned libraries of oligonucleotide tag-DNA signature sequence constructs, in which the DNA signature components are all of the same length. Such libraries are especially useful for large-scale parallel sequencing of DNA signature sequences prepared from a source population, such as mRNA or genomic DNA.

Abstract: A teaching aid comprises a frame (1), a plurality of elongate rods (2) mounted horizontally in the frame and spaced vertically from each other and a plurality of polyhedral blocks (3) rotatably mounted on each rod. Means are provided to releasably hold each block (3) in at least three discrete rotary positions on its respective rod (2).

Abstract: Apparatus for printing any line of characters comprises printing wheels on a common shaft, the wheels on the shaft together defining a printing line over a hammer. Each printing wheel is rotated by a respective stepping motor through a respective setting wheel. An aligner bar is inserted into notches in the wheels, prior to printing, to verify the alignment of the characters in printing position. The stepping motors are bi-directional and take the shortest path from a preceding printing position to the next printing position. The pulsing frequency may be ramped to give a higher stepping rate in the intermediate portion of each printing wheel movement.

Abstract: This invention is concerned with the high speed printing of a line of text on a sheet in very accurate registration with an edge of the sheet or another feature (for example an existing print line) on the sheet. The sheet is fed without preregistration on to a track (10, FIG. 1) which passes the printing station (20). A detector (16) adjacent the track senses the arrival of the edge or some other feature of the sheet and a printing control means (14) responsive to the detector signal initiates the firing of the printing hammer (22) when the print line reaches the printing station, a registered operation being thereby effected without stopping the sheet. The detector signal may start the operation of a counter (70, FIG.

Abstract: In apparatus for conveying successive stacks of sheets to a station at which an operation is to be performed on the stack, the sheets are advanced by pushing elements (14) to the station, at which a resilient finger (17) projects through a slot (16) in the track. The finger (17) aligns the leading edges of the sheets in the stack. When the stack of sheets is to be advanced, a slide (20) retracts. The finger (17) is pivotally mounted on the slide and its upper inclined edge engages the bottom rear corner of the slot when the slide is retracted, causing the finger to sink below the track until the slide is returned in time for the alignment of the next stack.

Abstract: To print on each of a number of sheets, the sheets are advanced, preferably in underlapped form, up to registering stops. When a sheet has been registered at the stops, suction is applied to an underlying conveyor, the stops are withdrawn and the sheet is advanced in steps to a printing station, the sheet being held in register by suction during this advancement. Printing takes place while the sheet is stationary and still held in register, between steps of movement. Suction may be switched on and off at the registering station by means of a movable perforated switch plate, the perforations of which are aligned, in a first position of the switch plate, with suction-conveying perforations in another plate or belt; in a second position of the switch plate its perforations are misaligned with the perforations in the other plate or belt, preventing the application of suction to an overlying sheet.