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A CO2 gas sensor using a combined solid electrolyte of a Na conducting Na20-A1203-4SiO2 glass and an yttria-stabilized zirconia was prepared, and its sensing properties in dry and wet gases were investigated using a variable flow rate of the test gases. The glassy electrolyte in the sensor was suitable as a CO2 sensing material because of its high density and good contact between the electrolytes. In a dry atmosphere, excellent results were obtained for the CO2 gas concentration dependence of the electromotive force (EMF), expressed by EMF (mV) = 547.5 -74.0 log [C0Jppm] at 470°C in which the sensitivity of 74.0 mV/decade was in fair agreement with the theoretical value based on a two-electron electrochemical reaction. In the case of wet CO. gas, the sensitivities and response time were depressed even for a high CO2 gas concentration. The decomposition of Na2CO3 into sodium oxide on the Pt electrode was accelerated in the presence of H9O. The reason for the depression of the sensing properties in a humid condition could be ascribed to its reformation reaction as a side reaction.

Abstract. Composite solid propellants experience aging process during storage, and their properties will alter. The stabilizer added was used to reduce the effects of aging. This research studied the influence of the stabilizer on changes of the composite solid propellant thermal decomposition due to the onset of aging during the 40 days of storage at a temperature of 333 K. AO 2246 as a stabilizer added by as much as 0 to 1% by weight of propellant binders. The testing method used is heating the samples at various heating rate using DSC. And the Ozawa method was used to determine the values of the activation energy and frequency factor on the Arrhenius parameters. The optimal composition of stabilizer was 0.5 wt% for those on the value of activation energy and frequency factors for unaged and aged propellants were nearly the same i.e. 196 kJ/mol and 1.22 x10 12 min -1 .