Grain size effects in barium titanate-revisited
The effects of grain size on the dielectric properties of barium titanate ceramics are reviewed from a historical perspective. The problem has been studied for 40 years, and great insight concerning the characteristics of fine grained materials has been gained. Nevertheless, the story has still to reach a satisfactory conclusion.
A healthy tissue tolerance study1,2 with Beagle dogs was carried out at the Finnish BNCT facility FiR 1 during February-March 1998. Three dose groups of dogs without boron carrier, each comprising five Beagles, and one dose group with BPA-F infusion were irradiated. Individual dose plans1 were done for each dog. The absorbed doses, which were actually delivered to healthy tissues, were monitored in vivo by placing the dosimeters on the shaved skin of the dogs or in the accessible cavities. In this study, absorbed gamma doses were monitored with thermoluminescent (TL) dosimeters, and neutron fluences were determined with activation foils. The obtained results were compared to the calculated values.