James M. Pope

The use of BaTiO3 as a solid-electrolyte to determine water vapor effects upon electrical transport mechanisms

Abstract Conduction of polycrystalline BaTiO 3 in the presence of water vapor has been investigated using a concentration cell with the barium titanate as a solid electrolyte. At a constant oxygen potential across the electrolyte, the transference number of ions within the electrolyte increased with higher water vapor concentrations in the anode compartment of the cell. The increased ionic conductivity (at a fixed temperature) was attributed to the presence of mobile proton and hydroxyl groups and/or an increase in the native ionic point defects of the ceramic.

Stable reactor fuel of controlled density using active UO2 powders

Abstract This paper describes a method for preparing thermally stable UO 2 fuel pellets from active starting powders with a considerable range of sintered density. This accomplishment is effected by introducing regions of large, stable porosity by variations in the powder preparation procedure. The final density is sensitively dependent on the ratio of the density reached in a prepressing (slugging) operation to the density of the presintered green pellet. As the slug density becomes greater than the green density, the sintered density falls off rapidly.