Time scale of magmatic processes in the 1707 eruptive activity of Fuji volcano, Japan, was estimated by the 238U-230Th-226Ra disequilibria observed in the 1707 volcanic products. The activity ratios of 226Ra/230Th in the products were larger than unity, being enriched in 226Ra relative to 230Th. The decay-corrected 226Ra/230Th activity ratio to the time of the eruption versus 238U/230Th activity ratio diagram for the 1707 volcanic products showed a positive correlation, suggesting that the 238U-230Th-226Ra disequilibria occurred during the magma genesis of Fuji volcano. The 230Th-226Ra disequilibria in the 1707 volcanic products suggested that the time scale from the magma genesis to the eruption, including the melting of the mantle wedge, magma storage and magmatic differentiation from basalt to andesite, was less than 8000 years.
Black pepper is easy to be contaminated by microorganism and often processed to γ-irradiation. ESR has been used for the detection of radicals induced in irradiated spices. Using ESR, we revealed the effects of moisture condition during storage of irradiated black pepper on the saturation behavior of ESR signal. The ESR spectrum of black pepper consists of a broad sextet centered at g=2.0, a singlet at same g-value and a singlet at g=4.0. The irradiation causes two new signals, one is the strong and sharp singlet signal at g=2.0 and the other is the side signal. We found that the signal intensity originated by the radicals of black pepper with and without radiation decayed in the high humidity condition during storage. The ESR signal intensity of irradiated black pepper decayed during storage and showed almost the same intensity level as that of non-irradiated black pepper during storage.
The Subcommittee of Japan Radioisotope Association on Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey every five years since 1982. The 6th survey was performed in June 2007. The estimated total annual number of examinations was 1.41 million, 11.5% less than the previous survey (2002). The scintigraphy most frequently performed was bone (38%), followed by myocardium and brain perfusion scintigraphy. 18F-FDG-PET dramatically increased. 131I therapy for thyroid cancer and hyperthyroidism has been also increasing steadily, while the number of in vitro radioassays has been decreasing continuously since 1992.