Abstract: Firstly, a custom designed 3D printer with x-y-z gantry robot with an accuracy of 0.1 ?m was adapted with a custom designed printing head (51b). Secondly, a two component silicone elastomer suitable for RP was developed that incorporates the desired characteristics and properties similar to those commercially available for the provision of facial and body prostheses. The silicone elastomer is composed of polydimethylsiloxane (PDMS) chains, filler, catalyst and crosslinker. By varying the amount of these components the mechanical properties of the silicone elastomer can be altered, for example, tensile strength, tear strength, hardness and wettability. To achieve these desired properties consideration must also be given to the set time and viscosity of the silicone elastomer and additionally the speed at which the material is printed.

Abstract: Systems, apparatuses and methods (“utilities”) for use in “internally” cooling the compressor of a gas turbine engine so as to approximate isothermal compression and thereby increase the power and/or efficiency of the engine. In one arrangement, a “cooling jacket” or heat exchanger having coolant circulating or passing therethrough may be mounted around an outer surface of the compressor to absorb heat or thermal energy generated from the compressor. In another arrangement, the stator blades of the compressor may include passages through which a coolant may be circulated or passed to absorb heat from air passing through the compressor.