A combined solvent extraction—liquid scintillation method is suggested for the determination of plutonium. The quenching by
twenty four extracting reagents was examined systematically, and the organo phosphorus extractants such as tributylphosphate
(TBP), bis-(2-ethyhexyl) phosphoric acid (HDEHP), and tri-n-octylphosphineoxide (TOPO) were shown to be least quenching compared
with amines and beta-diketones. Using TOPO, plutonium from 1 ng to 2 μg was determined within 5% of standard deviation, and
the detection limit was 3·10−10 g of239Pu. The quenching by the different ions and the effects of the radioactive elements were also shown.
Authors:N. Takahashi, D. Yano, Y. Tamiya, and H. Baba
Anomalous behavior of radioiodine was found in solvent extraction. Iodine was extracted into CS2 from acidic solution over a wide range of iodine concentration. The distribution ratio was obtained by measuring the -rays from iodine-131. The ratio drastically changed at about 10–5 mol l–1. The change is readily explained by the kinetic behavior of radioiodine.
Authors:T. Baba, T. Yamada, Y. Nishikawa, and H. Yoshida
stability of para (p--)
and ortho (o-)
isomers was investigated by CRTG and reaction kinetic analysis. The temperature
started the mass decrease of o-isomer was
about 20C lower than that of p-isomer
by CRTG. The activation energies of thermal decomposition of o-
and p-isomers were 136.9 and 153.4 kJ mol–1,
respectively. The effect of steric hindrance on heat of formation was calculated
by AM1 method using Win MOPAC3.0 for the model compound of p-
and o-isomers. The lower stability of o-isomer was the results of the steric hindrance
between the ethylene unit of aromatic ring and three alkyl chains.
Authors:S. Sugihara, S. Osaki, T. Baba, Y. Tagawa, Y. Maeda, and Y. Inokura
Activity concentrations of radionuclides,7Be,210Pb and210Po, in precipitation (rain, throughfall and stemflow), wood and soil were determined by using gamma-ray and alpha-ray spectrometry
to estimate the migration behavior of these radionuclides in the forest canopy. The activity ratios between output and input
precipitations for the forest canopy were 0.53 of7Be, 0.79 of210Pb and 1.5 of210Po for Pasania edulis forest. A dynamic model of the transport and fate of radionuclides in the forest ecosystem was constructed.
Mean residence times of radionuclides were 56 days for7Be, 765 days for210Pb and 653 days for210Po for Pasania edulis forest.
Authors:A. Yokoyama, K. Takesako, T. Saito, H. Baba, Y. Ohkubo, A. Shinohara, and M. Furukawa
Nuclear reactions of165Ho induced by 1.0 GeV15N or 1.8 GeV14N ions and those of141Pr induced by 2.3 GeV or 3.8 GeV40Ar ions have been studied by off-line -ray spectrometry. Mass distributions of the products were confirmed to reveal a limiting characteristics at projectile energies beyond 2 GeV. Longitudinal momentum transfer was measured with a thick-target-thick-catcher technique. The results demonstrated that a provisional limiting of the recoil velocity appears in the energy range of 2–10 GeV, besides the ultimate limiting condition already pointed out. The coincidence in the onset energy of the limiting behavior was interpreted as the result of the existence of the limit heating of nucleus.
Authors:K. Takamiya, T. Inoue, K. Nakanishi, A. Yokoyama, N. Takahashi, T. Saito, H. Baba, and Y. Nakagome
In order to estimate the deformation rate of fission fragment at the scission point for thermal neutron-induced fission of233,235U and239Pu, double-velocity and double-energy measurements were carried out. As the result of the estimation of the deformation rate,
two types of scission point configurations were found. One type is composed of deformed light and heavy fragments, and the
other type is a combination of deformed light and spherical heavy fragments. Mass and total kinetic energy distributions were
sorted in two distributions by means of the type of configuration.
Authors:S. Basay, A. Cimen, Y. Baba, A.B. Yildirim, and A.U. Turker
Interest in organic growing systems that means no harm to the environment, mankind, and the world’s natural ecosystem is increasing. This study evaluated the impact of organic versus conventional cultivation method on eggplants (Topan-374 and Pala-49), tomatoes (Rio Grande and Pink), and bell pepper (Kandil dolma) considering individual phenols, total phenol-flavonoid content, antioxidant capacity, and antibacterial potential. Peel and pulp of eggplants were evaluated separately. Organic cultivation enhanced trans-ferulic acid in the peels of both eggplant cultivars and the pulp of Pala-49. Organic Pala-49 had also higher amounts of cyanidin and caffeic acid in the peel, and only caffeic acid in the pulp. Chlorogenic acid was found in higher quantities in organic Rio Grande tomato and bell pepper. All organically grown vegetables in our study had significantly higher total phenol and flavonoid contents than conventional ones except Pink tomato. Organic farming significantly enhanced the antioxidant capacity of both eggplant cultivars. Only organic peel of Pala-49 eggplant cultivar had antibacterial activity against Staphylococcus epidermidis. Organic cultivation has an advantage in terms of antioxidant potential and phenolic constituents, and it enhanced the nutraceutical potential of both cultivars of eggplant, Rio Grande tomato, and bell pepper.
Authors:Y. Nagame, I. Nishinaka, Y. Zhao, K. Tsukada, S. Ichikawa, Z. Qin, H. Ikezoe, Y. Oura, K. Sueki, H. Nakahara, M. Tanikawa, T. Ohtsuki, S. Goto, H. Kudo, Y. Hamajima, K. Takamiya, K. Nakanishi, and H. Baba
The correlation among the fission threshold energy, the scission configuration and the mass yield distribution has been studied
in proton-induced fission of light actinides. It was found that there exist at least two fission paths from the threshold
region to the scission. The elongated scission configuration is related with the fission process that goes over a higher threshold
energy and results in a symmetric mass division mode, while the compact scission configuration with the process that experiences
a lower threshold and ends up with an asymmetric mass division mode.
Authors:A. Yokoyama, S. Morimoto, T. Inoue, J. Sanada, H. Araki, T. Saito, H. Baba, S. Shibata, A. Shinohara, T. Muroyama, and Y. Ohkubo
Target-like products, that is,191–200Au,185–200Pt, and183–195Ir, from197Au target bombarded with12C ions at the energies of 180, 230, and 400 MeV/u were measured by using off-line gamma-ray spectrometry combined with chemical
separation procedures. Spallation systematics by Rudstam reproduces well the measured cross sections for formation of platinum
and iridium isotopes. It was found that the cross sections of gold nuclides increase with increase of the incident energy
in the range studied and they are enhanced if compared with the reported proton-induced reaction of gold at a similar incident
energy. It is suggested that the electromagnetic dissociation process plays a role for production of such gold nuclides.