Abstract: A planographic printing member comprising a substrate, an oleophilic layer, an infra-red sensitive/ablatable layer, and a hydrophilic layer. The hydrophilic layer is derived from a silicate solution, optionally containing particulate materials such as alumina and/or titania. The printing member may be exposed to radiation from a laser which ablates the infra-red sensitive/ablatable layer to reveal areas of the oleophilic layer. An exposed printing member may be used in wet lithographic printing.

Abstract: A control system for an aircraft gas-turbine engine has positive and negative acceleration control units. Each control unit has a memory storing values of the maximum or minimum desired rate of change of fuel flow at different speeds beyond which surge or extinction will occur. The control units produce output signals, in accordance with the engine speed and acceleration, for controlling fuel flow so that it follows closely within the surge or extinction curves. The system also has amplitude gates that pass one or the other of these output signals to the engine if the speed of engine demanded by the pilot is such as to cause surge or extinction.