3.303(0.30)(0.50 -0.085) f480X0.50 -0.30) log (0.50)f0.30 -0.085) ' k = . I . k = 0.02399 log 1.158.' k = 15.28 X lo-' per mole per second. ( B ) Where a = bFor those specimens where the initial concentrations, a and b, were equal, the equation for calculation of the specific reaction rate k takes the formTo illustrate the use of this equation, a sample calculation is given for an addition of 0.50 mole of cobalt to the frit containing 0.50 mole of CuO. This specimen was also fired for 8 minutes at 871'C. and showed a 2.15% (0.105 mole) reduction of copper. a = 0.50 mole. 2 = 0.105 mole. t = 480 seconds. 1 0.105 k = -. 480 (0.50)(0.50-0.105)' k = 11.08 x lo-' per mole per second.
AcknowledgmentThe writers wish to express their sincere gratitude to the Armco Steel Corporation, whose fellowship in the Department of Ceramic Engineering at the University of Illinois helped make this work possible.The dielectric constant and dissipation factor of both single-crystal and polycrystalline alumina were measured in air over the frequency range lo2 t o 3 X 105 cycles per second, in the temperature interval 900' to 1300'C. The three-electrode guard-ring method was used. The observed dielectric losses were due predominately to freeelectron conduction mechanisms. The volume conductivity of single-crystal and polycrystalline alumina was calculated from the high-frequency data. The temperature dependences of the volume conductivity for two single crystals of different thicknesses were similar. The large thermal activation energy indicated intrinsic conductivity ; the energy band gap of alumina was calculated to be approximately 7.3 electron volts. The bulk conductivities of the polycrystalline alumina were considerably higher than the single-crystal values, presumably because of impurities in the polycrystalline material. The results were compared with values previously reported in the literature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.