Authors:T. Fujii, H. Yamana, K. Takamiya, M. Watanabe, and H. Moriyama
Adsorption behavior of fission products in nitric acid solution on various alloys and metals was studied by using a multitracer produced by neutron irradiation of UO2. The adsorption behavior of the fission products 99Mo, 131I, 132Te, 140La, and 143Ce, and 239Np was simultaneously studied. Some chemical decontamination tests were also examined. Clear adsorption of 99Mo, 131I, and 132Te was observed, whereas adsorption of 140La, 143Ce, and 239Np was not. The adsorption characteristics were discussed by considering anion-exchange reaction and surface complexation.
Authors:T. Fujii, K. Obata, T. Kubota, M. Kamiya, and H. Yamana
The volatility of tellurium and some other fission products was radiochemically studied in heated nitric acid solutions. As tracers 121Te produced by bremsstrahlung of an electron LINAC and other fission products produced by neutron irradiation were used. The distribution rate of radionuclides between the mother solution and the condensate, was considered as volatility, and was determined. The volatility of tellurium was found to be small and close to that of cesium. Volatilization tests were also performed in the presence of large amounts of solutes.
Authors:J. Takada, K. Nishimura, Y. Tanaka, N. Fujii, and M. Akaboshi
We have investigated the concentrations of REEs in fern leaves collected indifferently to the fern species from 9 sampling sites in Japan using INAA. The results indicated a large variation in the values obtained between fern leaves. In the present investigation we applied the same analytical method on the samples (Blechnaceae, a kind of fern, mature and developing leaves were collected from the same plant) restrictively gathered from the University Forests in Ashiu, Kyoto University. It was demonstrated that the variations in the REE concentrations decreased by one to two order of magnitude, and that the REE contents in developing leaves were also one to two orders of magnitude lower than those in mature leaves. It can be considered that fern accumulates REEs with their growth stages.
Authors:F. Sakamoto, M. Izumo, K. Hashimoto, and Y. Fujii
The synthesis of [γ-32P]ATP with high specific radioactivity was investigated by the enzymatic method. We utilized a part of the glycolytic pathway
which consists of three reaction steps. First, we examined the maximum radioactivity of H332PO4 without the decrease of labeling yield. Next, we examined the minimum amount of reagent without the decrease of labeling
yield, because some reagents contain the phosphorus species as impurity. In this paper, we propose the optimum condition for
synthesis of [γ-32P]ATP with high specific radioactivity. As our calculation, we will be able to obtain about 220 TBq/mmol specific radioactivity
using 1.5 GBq of H332PO4.
Authors:M. Koyama, J. Takada, K. Kamiyama, N. Fujii, J. Inoue, K. Issiki, and E. Nakayama
In order minimize the possible contamination during storing and pre-treatment of such pure samples as ice and snow collected in Antarctica, trace elements in experimental tools such as bottles, beakers, tubings and filters were determined by neutron activation analysis. By using well certified tools, ice and snow samples from Antarctica and high mountains in China and in Japan were analyzed. Relative concentrations of volatile elements such as Zn, Cd, As, Sb or Ag to Al or Fe which are major components in the earth crust were found to be 10 to 1000 times higher than in the ordinary soil for the samples from Antarctica and Mt. Naimonanyi in China.
Authors:T. Kudou, H. Ohyama, E. Simoen, C. Claeys, J. Vanhellemont, K. Sigaki, Y. Takami, and A. Fujii
Results are presented of an extended study on the degradation of electrical and optical performance and the induced lattice
defects of In0.53Ga0.47As p-i-n photodiodes, subjected to a 20 MeV alpha-ray irradiation. The difference in radiation damage with 1 MeV fast neutrons
and 1 MeV electrons is discussed taking into account the energy transfer. The radiation source dependence of performance degradation
is attributed to the difference of mass and the probability of nuclear collision for the formation of lattice defects.
Authors:K. Fujii, Y. Matsumoto, Y. Kaieda, D. Kobayashi, Y. Umebayashi, and S. Ishiguro
chloro complexation has been studied by titration calorimetry and spectrophotometry
in solvent mixtures of N-methylformamide
(NMF) and N,N-dimethylformamide
(DMF). It revealed that a series of mononuclear CoClnn(2–n)+
(n=1–4) complexes are formed in the
mixtures of NMF mole fraction xNMF=0.05
and 0.25, and the CoCl+, CoCl3–
and CoCl42– complexes
in the mixture of xNMF=0.5,
and their formation constants, enthalpies and entropies were obtained. As
compared with DMF, the complexation is markedly suppressed in the mixtures,
as well as in NMF. The decreasing formation constant of CoCl+
with the NMF content is mainly ascribed to the decreasing formation entropy.
DMF is aprotic and thus less-structured, whereas NMF is protic to form hydrogen-
bonded clusters. In DMF-NMF mixtures, solvent clusters in neat NMF are ruptured
to yield new clusters involving DMF, the structure of which depends on the
solvent composition. The entropy of formation of CoCl+
will be discussed in relation to the liquid structure of DMF, NMF and their
Authors:T. Suzuki, K. Otake, M. Sato, A. Ikeda, M. Aida, Y. Fujii, M. Hara, T. Mitsugashira, and M. Ozawa
The separation of Am and Cm by using the tertiary pyridine resin embedded in silica beads was studied in nitric acid/methanol
mixed solvent system. This separation system of Am and Cm is very simple and easy. The adsorption and separation behaviors
of Am and Cm were investigated with changing the nitric acid and the methanol concentrations. It was confirmed that Am can
be almost completely separated from Cm.