Abstract: In one embodiment, a method for arbitrating wireless communications includes determining the nature of wireless communications to be transmitted instead of a type of packet to be transmitted, determining priorities of the wireless communications relative to the determined nature, and controlling transmission of the wireless communications according to the determined priorities.

Abstract: An interface of an option pack configured to be used in conjunction with the main unit of a Personal Digital Assistant (PDA). An option pack comprising a connector configured to mate with the main unit of a PDA and provide a plurality of signal paths and a memory storage device such as an EEPROM can be used to store identification and functionality information to be conveyed to the main unit upon insertion of the option pack connector into the main unit. The interface on the option pack provides serial and parallel exchanges between the option pack and main unit and provides safeguards against draining the power on the main unit upon insertion. Further, the interface allows a software application and associated drivers to be downloaded onto the main unit temporarily and removed when a user has no further use for the application or option to save memory space on the main unit.

Abstract: Disclosed is a method for stripping nickel aluminide coatings of up 10 weight percent aluminum from nickel base alloy substrates at room temperature. The preferred solution contains by volume percent 43-45 nitric acid, 7-12 hydrochloric acid, 0.1-1.5 sulfuric acid, balance water; it also contains 0.008-0.025 moles per liter of ferric chloride, at least 0.016 moles per liter copper sulfate. The ratio between the sulfate and chloride is 2:1 or greater.

Abstract: Disclosed is a process for machining nickel-base superalloys wherein a thermal-effect process, such as laser or electric discharge machining, is first used to remove material but leaves a recast layer. Next a chemical milling process is used wherein the etchant only attacks and removes the recast layer. The etchant is comprised by volume percent of 40-60 HNO.sub.3, 5-20 HCl, and balance H.sub.2 O, with which is included 0.008-0.025 moles/liter FeCl.sub.3 and at least 0.016 moles/liter CuSO.sub.4. The FeCl.sub.3 improves removal rate but tends to cause unwanted pitting and intergranular attack. These tendencies are inhibited by the addition of CuSO.sub.4 ; preferably the molar ratio of CuSO.sub.4 to FeCl.sub.3 is 2:1. The beneficial combination of FeCl.sub.3 and CuSO.sub.4 is usable in other etchants.

Abstract: Chemical milling of cast superalloys having high tungsten contents is advantageously accomplished with an etchant which consists by volume percent of 40-60 concentrated HNO.sub.3, 0.6-0.8 concentrated HF, 30-70 H.sub.2 O, with which is included at least 0.008 moles/liter CuSO.sub.4 and 0.0016-0.025 moles/liter FeCl.sub.3. Preferably the molar ratio of CuSO.sub.4 to FeCl.sub.3 is 2:1 and etching is accomplished in the range 50.degree.-80.degree. C.

Abstract: Nickel aluminide and like coatings are stripped from nickel base superalloy substrates using a 60.degree.-71.degree. C. solution consisting essentially by volume percent of 43-48 nitric acid, 7-12 hydrochloric acid, balance water, and containing 0.008-0.025 mole/liter ferric chloride and at least 0.016 mole/liter copper sulfate. Coating removal is rapid while significant attack of the substrate is avoided.

Abstract: The adherence and wear resistance of chromium alloy electroplates on titanium is improved by pretreating the substrate to form a chromium conversion coating, and post-treating the substrate at a temperature at about 700-820.degree. C. (1300-1500.degree. F.) for about 1-300 hours. The pretreatment is comprised of the formation of a chromium conversion coating from an acid chromate solution; a preferred solution is comprised of hydrofluoric acid, sodium chromate, and water. The post treatment causes diffusion sufficient to obtain a bond but avoids completely interdiffusing the chromium alloy electroplate, to preserve the wear resistance of the electroplate surface.

Abstract: Chemical milling of cast superalloys having high tungsten contents is advantageously accomplished with an etchant which consists by volume percent of 40-60 concentrated HNO.sub.3, 0.6-0.8 concentrated HF, .[.30.]..Iadd.40.Iaddend.-70 H.sub.2 O, with which is included at least 0.008 moles/liter CuSO.sub.4 and 0.0016-0.025 moles/liter FeCl.sub.3. Preferably the molar ratio of CuSO.sub.4 to FeCl.sub.3 is 2:1 and etching is accomplished in the range 50.degree.-80.degree. C.