Abstract: A method and system for purifying contaminated refrigerants is described. The refrigerant is heated in a controlled manner to separate it into fractions, one fraction having the pure refrigerant and the remaining fractions containing the contaminants. The temperature of the refrigerant fraction output being closely monitored and controlled to ensure that it is the correct required fraction.

Abstract: There is provided a system for monitoring a replaceable unit. The system comprises a passive memory device attached to the replaceable unit forming part of an assembly such as an engine. The passive memory is for storing and for providing access to replaceable unit information comprising unit identification and usage information. The system may further comprise an event detector which may be embodied as an electronic engine controller (EEC) operatively connected to the engine, for accumulating the usage information related to the replaceable unit, and for communicating with the passive memory device to update the unit information stored in the passive memory device with the usage information.

Abstract: Disclosed are methods for solution mining of evaporite minerals, such as trona, comprising drilling an access well and at least two lateral boreholes; injecting a fluid; circulating the fluid through the lateral boreholes with a controlled fluid flow; and collecting a pregnant solution. Also disclosed are methods of solution mining that include injecting an aqueous solution into an underground trona cavity at a temperature sufficient to maintain at least a portion of the solution in the cavity in the Wegscheiderite solid phase region; removing aqueous solution from the cavity; and recovering alkaline values from the removed aqueous solution. Also disclosed are methods of solution mining that include injecting an aqueous solution into an underground trona cavity; removing aqueous solution from the cavity, wherein the temperature of the removed aqueous solution is at about the TWA point temperature; and recovering alkaline values from the removed aqueous solution.

Abstract: There is provided a method for welding together two metal components to form a large structure suitable for use as an aerospace component. The method comprises the steps of providing two metal components to be welded together, each component having a length, a width, a height and a surface to be welded, the surface to be welded of at least one of the metal components including a feature extending substantially the length of the component, the feature reducing the contact width of the surfaces to be welded of the two components to less than the width of each component; and welding together the components. There is also provided a large structure so created. There is also provided a method for welding together two metal components to form a part or a whole of a spar for a wing for an aircraft and a spar so created.