The notebooks were related to research work by Bunsaku Arakatsu, a professor at the university whom Sankei said was asked by the Japanese navy to develop an atomic bomb during the war. Also found were drawings of a turbine-based centrifuge apparently to be used for the study of uranium enrichment. It was dated March 1945. Another blueprint was found of a centrifuge that a Japanese company, Tokyo Keiki, was producing, with a notation indicating the device was scheduled to be completed Aug. 19, 1945 — four days after Japan announced that it was surrendering.