Specific activities 60Co/Co in a steel sample from Yokogawa Bridge, 1295 m NNW, and three steel samples from the Atomic-Bomb Dome, 161 m NW from the hypocenter were measured by gamma-ray spectrometry and neutron activation analysis. The results expressed in a unit of dpm/mgCo were, 0.212±0.06 for Yokogawa Bridge, and 529±40, 561 ±38, and 524±74 for the Atomic Bomb Dome, at the time of bombing, which are consistent with previous data by Hashizume et al. for steel rings on the surface of roofs of buildings. The data are expected to serve for verification of the bomb neutron transport calculation.
An automatic synthesis equipment for 18FDG by micro-computer control was manufactured for trial. In order to perfectly prevent a mistaken action, new methods were introduced in the hardwires and the softwares. Moreover, if a part of the control becomes out of order, only that action is changed over to manual operation immediately, and it was made so that the synthesis can be continued. By this means, the synthesis became feasible without fail.
Water hydrology was studied by neutron radiography when water absorbing polymer was added into soil. The water movement near the root of soybean during its growth was obtained, nondestructively, from the change of the darkness in the image. It was shown that the water was mainly supplied from the upper part of the sand. Two kinds of water absorbing polymers (polyacrylic polymer and polyvinyl alcohol copolymer), which were expected to improve the desert for the water sustainability, were added to the sand and then the water movement around the root was analyzed. When polyacrylic water absorbing polymer was mixed with the sand, water was supplied only from the sand and not from the polymer, therefore the root was not developed well. However, in the case of polyvinyl polymer, water was first supplied from the sand and then from the polymer, which phenomenon was suggested by the shrinking image of the polymer.
In order to evaluate the usefulness of volume mesurement of small organ using single photon emission computed tomography (SPECT), phantom study with six cylinder (1-50ml) and three thyroid phantoms (12-34 ml) with various131I concentration were performed. The optimal threshold level was quite changed according of the shape, size of phantoms and131I activity: small change of the threshold level resulted in considerable difference of the volume. The volume measurement of the small organ such as thyroid using SPECT might not accurate.