Abstract: A process for devulcanizing a rubber vulcanizate by desulfurization involves suspending a rubber vulcanizate crumb in a solvent which preferably swells the rubber vulcanizate before or during the devulcanization reaction and adding an alkali metal, such as sodium, to the suspension. The alkali metal cleaves mono-, di- and polysulfidic cross-linkages in the rubber vulcanizate to liberate rubber polymer having a molecular weight substantially equal to that of the rubber polymer prior to vulcanization. Carbon black may also be recovered for re-use in accordance with the process of the present invention. Devulcanized rubber may be subjected to a re-vulcanization reaction without separation of rubber polymer from the solvent by addition of an appropriate curing mixture.

Abstract: The present invention is directed toward a process for regenerating sodium hydroxide (NaOH) from aqueous solutions of sodium sulfide (Na.sub.2 S) comprising heating aqueous sodium sulfide in the presence of a metal selected from the group consisting of iron and cobalt, for a time and at a temperature sufficient to form a metal sulfide, sodium hydroxide and molecular hydrogen.

Abstract: A method is provided for wire bonding an aluminum wire to a surface of a lead of an electronics package. The method entails a nickel plating process and an ultrasonic bonding process which together cooperate to form a reliable and highly repeatable joint between the wire and the lead member. The ultrasonic bonding process is specifically tailored to the nickel plating produced by the plating process, so as to significantly enhance the bond strength of the resulting ultrasonic bond joint. The plating process is devised to produce a nickel plating which is thicker than that generally practiced, and whose surface is characterized as having a relatively smooth microfinish which unexpectedly serves to enhance the bond strength of the ultrasonic bond joint.

Abstract: A method of reducing the permeability of an area of a subterranean formation is disclosed. An alkali metal silicate foam is produced by injecting into the formation a solution of alkali metal silicate and a chemical surfactant, and a non-condensible gas. The foam hardens into a substantially impermeable solid. The foam may be used to reduce permeability in areas of the formation which have been steam swept during steam stimulation cycles. Thus, subsequent steam stimulation cycles will be directed to uncontacted areas of the formation.