A study has been made at 25" of the influence of pH upon the relative quantum yields for the consumption of oxalate and the production of carbon dioxide, carbon monoxide, and uranous ion by light of 254 nm absorbed by the uranyl oxalate actinometer system. The uranyl ion was at 0.01 F , the oxalate at 0.06 F , and initial pH was at 0-6. About 12% of the oxalate was decomposed. The quantum yields for the consumption of oxalate were found to be independent of the pH between 1 and 5 but to decrease outside this range. The reaction at all values of pH was found to consume acid. The moles of carbon dioxide produced in all forms (COZ, H&Oa, HCOa' , COa2-and the uranyl carbonate complexes) per mole of oxalate consumed very nearly equalled unity at pH 0 to 5. The moles of carbon monoxide produced per mole of oxalate consumed were always less than unity; they decreased with increase in pH abruptly between pH 1 and 2, and became negligible above pH 3. The mole ratio of uranous ion produced to oxalate consumed increased slowly from about 0.03 between pH 1.5 and 4 to about 0.08 at pH 6. The mechanisms of the reactions are discussed.

Diagnostic experiments were conducted on a DF chemical laser to obtain data on the reaction zone structure for laminar mixing and when the mixing has been augmented by gas jet injection at the reactant interface. DF and HF emission from the reaction zones was recorded using infrared sensitive film and an IR scanner with an InSb detector; DF small-signal gain experiments were also conducted. The IR scanner and gain measurements were used to verify the photographic data which showed a decrease in the axial mixing length from 5 cm to 0.5-1.0 cm in going from the laminar to the augmented mixing mode.

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An optical sensor system extends gas temperature measurement capability in turbine engines beyond the present generation of thermocouple technology. The sensing element which consists of a thermally emissive insert embedded inside a sapphire lightguide is capable of operating above the melting point of nickel-based super alloys. The emissive insert generates an optical signal as a function of temperature. Continued development has led to an optically averaged system by combining the optical signals from four individual sensing elements at a single detector assembly. The size of the signal processor module has been reduced to overall dimensions of 2 x 4 x 0.7 inches.The durability of the optical probe design has been evaluated in an electric-utility operated gas turbine under the sponsorship of the Electric Power Research Institute. The temperature probe was installed between the first stage rotor and second stage nozzle on a General Electric MS7001B turbine. The combined length of the ceramic support tube and sensing element reached 1 .5 inches into the hot gas stream. A total of over 2000 hours has been accumulated at probe operation temperatures near 1600°F.An optically averaged sensor system was designed to replace the existing four thermocouple probes on the upper half of a GE F404 aircraft turbine engine. The system was ground tested for 250 hours as part of GE Aircraft Engines IR&D Optical Engine Program. Subsequently, two flight sensor systems were shipped for use on the FOCSI (Fiber Optic Control System Integration) Program. The optical harnesses, each with four optical probes, measure the exhaust gas temperature in a GE F404 engine.