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Idesaki, Akira; Seguchi, Tadao*; Tamura, Kiyotoshi; Oshima, Takeshi; Shimada, Akihiko; Kudo, Hisaaki*
no journal, ,
The degradation of polyvinylchloride (PVC) of cable insulation was investigated by accelerated radiation and thermal ageing. The sheets of PVC as same formulation as cables were subjected to thermal ageing at temperature range 100-135
C and/or to radiation ageing by Co-60 
-rays at a dose rate of 1kGy/h in air. The degradation was evaluated by the tensile test and by the weight change. The relations between elongation at break and change of weight by loss of plasticizer were analyzed. At higher temperature, the plasticizer evaporates to cause the decay of tensile properties.
Shimada, Akihiko; Seguchi, Tadao*; Tamura, Kiyotoshi; Oshima, Takeshi; Idesaki, Akira; Kudo, Hisaaki*
no journal, ,
Silicone rubber (SiR) sheets with different formulation were examined on the two points, specimen's thickness and thermal and radiation combined accelerated ageing. The 0.5 and 2 mm thick sheets were aged by thermal at up to 235C and Co-60 rays radiation with 1 kGy/h up to 800 kGy. The degradation was measured by tensile testing and gel fraction and swelling experiments. For check the distribution of degradation in depth of sheet, the 2 mm sheet sample was sliced by 0.3 mm thickness after ageing. The results indicated that the degradation progressed uniformly throughout the 2 mm thick sheet. For the ageing combination, the degradation by three different combinations was examined, that is, (a) simultaneous ageing, (b) thermal and radiation sequential ageing, and (c) radiation and thermal reversed sequential ageing. Elongation at break indicated that the order of degradation mild to severe was reverse sequential, sequential, simultaneous ageing.
Lu for radioimmunotherapyWatanabe, Satoshi; Hashimoto, Kazuyuki; Watanabe, Shigeki; Iida, Yasuhiko*; Hanaoka, Hirofumi*; Endo, Keigo*; Ishioka, Noriko
no journal, ,
Br-MBBGWatanabe, Shigeki; Hanaoka, Hirofumi*; Liang, J. X.; Watanabe, Satoshi; Iida, Yasuhiko*; Endo, Keigo*; Ishioka, Noriko
no journal, ,
Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Kitatsuji, Yoshihiro; Ishii, Yasuo; Sato, Tetsuya; Li, Z.; Sato, Nozomi; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.
no journal, ,
Electrochemical studies of nobelium (No) and mendelevium (Md) using an electrolytic column chromatography at JAEA will be presented. The isotopes 
No and Md were produced in the 
Cm(
C, 5n) and Cm(
B, 4n) reactions, respectively, at the JAEA tandem accelerator. In the experiment of No, the oxidation of No
to No
in 0.1 M 
-hydroxyisobutyric acid (-HIB) was studied with comparing with the elution of Sr and Yb. At the applied potential of 0.2 V, No was not eluted with -HIB. This adsorption of No was the same as that of Sr, indicating that No was bound in its stable divalent state. On the other hand, the elution of No in -HIB was observed at 1.2 V at the position of Yb, which demonstrated that No was successfully oxidized to No. Reduction of Md to Md was also successfully carried out with the apparatus in 0.1 M HCl.
Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Shimizu, Takao*
no journal, ,
The uranium dissolved in seawater is extremely low concentration of 3.3 ppb. However, the total amount of uranium resource in seawater is 4.5 billons tons which is one thousand times of that in terrestrial ores. For uranium collection from seawater, amidoxime group was selected as a high affinity group in adsorbent. This adsorbent was synthesized by grafting of acrylonitrile and subsequent chemical treatment with hydroxylamine. The collection of uranium from seawater was performed in marine experiments at Aomori and Okinawa, Japan. In Aomori, 350 kg of the fibrous adsorbent stacks were dipped at 7 km offing of Aomori seashore. In total 9 tests over three years, 1 kg of uranium could be collected successfully as a yellow cake. A new braid type adsorbent has been developed to achieve the practical cost of uranium collection. The adsorption performance in Okinawa marine experiment indicated 1.5 g-U/kg-ad for 30 day soaking. The promising collection cost reached 25 thousand yen/kg-U which is equivalent to 
96/lb-U
O
.
Tsukui, Narutaka; Yamada, Keiichi*; Watanabe, Shigeki; Hanaoka, Hirofumi*; Oku, Hiroyuki*; Endo, Keigo*; Ishioka, Noriko; Matsuo, Ichiro*
no journal, ,
Sch
del, M.
no journal, ,
Experimental achievements and perspectives of the chemistry of superheavy elements will be presented.
Seguchi, Tadao*; Tamura, Kiyotoshi; Shimada, Akihiko; Idesaki, Akira; Oshima, Takeshi; Kudo, Hisaaki*
no journal, ,
The degradation mechanisms of polymer materials as PE, EPR for cable insulations in a nuclear power plant were studied by accelerated thermal and radiation ageing. The contribution of stabilizers to polymer degradation was investigated by the measurements of oxidation products, content of stabilizers, and also mechanical properties. It was found that an antioxidant among the stabilizers was very effective to decrease the thermal oxidation but less effective to the radiation induced oxidation. The content of the antioxidant decreases by evaporation during thermal ageing and by decomposition with dose during radiation ageing. The new degradation mechanisms in polymer ageing are proposed.
Shimojo, Kojiro; Mitamura, Hisayoshi; Naganawa, Hirochika
no journal, ,
no abstracts in English
Endo, Hitoshi; Nishida, Toshihiko*; Shibayama, Mitsuhiro*; Li, H.-J.*; Haraguchi, Kazutoshi*
no journal, ,
Poly(N-isopropylacrylamide) (PNIPA)clay nanocomposite hydrogels (NC gels) possess extraordinary superior mechanical properties. We have investigated the structure of NC gel by means of contrast variation small-angle neutron scattering (CV-SANS) technique. By applying CV-SANS in a sophisticated manner, the partial scattering functions of each component can be decomposed quantitatively. The extracted partial scattering functions of clay, polymer, and the polymer-clay cross-term were analyzed in detail, and the selective interaction between clay and polymer is revealed. On the basis of these structural observations, it is confirmed that the clay nanoparticles serve as 2-dimensional cross-linkers. Furthermore, the detailed structure of uniaxially-stretched NC gel was also studied by applying CV-SANS, and microscopic origin of the deformation mechanism of NC gel was explored.
Esaka, Fumitaka; Magara, Masaaki; Suzuki, Daisuke; Miyamoto, Yutaka; Lee, C. G.; Kimura, Takaumi
no journal, ,
In this study, inductively coupled plasma - mass spectrometry (ICP-MS) is applied to the analysis of plutonium isotope ratios in individual particles. Prior to the measurement, individual plutonium particles in samples are identified by using scanning electron microscope (SEM) and are transferred to each Si chip by a micro-manipulator attached to the SEM system. After removed from the SEM chamber, each particle is dissolved with HF-HNO solution for subsequent ICP-MS analysis. As a result, the 
Pu/
Pu plutonium isotope ratios in individual particles with the diameter of around 1 micro-meter are successfully determined with good precision. A remaining subject to be solved is the mass interferences by co-existing elements such as americium. In order to remove the interferences, we are developing methods for chemical separation of americium and plutonium, based on anion exchange and capillary electrophoresis systems.
Kimura, Takaumi; Magara, Masaaki; Miyamoto, Yutaka; Esaka, Fumitaka; Lee, C. G.; Suzuki, Daisuke; Yasuda, Kenichiro; Inagawa, Jun; Shinohara, Nobuo
no journal, ,
no abstracts in English
Itakura, Ryuji; Hasegawa, Hirokazu*; Kurosaki, Yuzuru; Yokoyama, Atsushi; Oshima, Yasuhiro*
no journal, ,
When neutral molecules are partly ionized in intense laser fields (I
35 TW/cm
), a hole in the rotational wave packet of the remaining neutral NO is formed by the ionization, whose rate depends on the alignment angle of the molecular axis with respect to the laser polarization direction. Rotational state distributions of NO are experimentally observed with the spectroscopic technique and then the characteristic feature that the population at higher J levels is increased by the ionization can be identified. Numerical calculation for solving time-dependent rotational Schr
dinger equations including the effect of the ionization is carried out. The numerical results suggest that NO molecules aligned perpendicular to the laser polarization direction are dominantly ionized at the peak intensity of I = 42 TW/cm, where the multiphoton ionization is preferred rather than the tunneling ionization.
Itakura, Ryuji; Hosaka, Koichi*; Yamanouchi, Kaoru*; Yokoyama, Atsushi
no journal, ,
In order to clarify the mechanism of dissociative ionization of ethanol in intense laser fields, the correlation maps P(E
, E
), where E and E denote kinetic energy of an electron and a fragment ion, respectively, are obtained by photoelectron-photoion coincidence momentum imaging. The kinetic energy distribution of the ions at a specific electron kinetic energy of electrons E are reproduced by an exponential curve of exp(-E/E), where E is a variable parameter, suggesting that the intramolecular energy redistribution proceeds efficiently in the course of the dissociation process after the ionization.
Itakura, Ryuji; Ikuta, Tomoya*; Hosaka, Koichi*; Akagi, Hiroshi; Yamanouchi, Kaoru*; Yokoyama, Atsushi; Kannari, Fumihiko*
no journal, ,
When ethanol molecules are irradiated with an intense UV pulse (400 nm,100 fs, I = 10 TW/cm), channel-specific photoelectron momentum images correlated with C
H
OH
, CH
OH, CHOH, and CH show different features, suggesting that different electronic and vibrational state distributions are prepared upon the ionization for the respective product ion channels.
Oka, Kiyoshi; Seki, Takeshi*; Komori, Yuki
no journal, ,
We developed a new minimally invasive laser device system using a composite-type optical fiberscope. The fiberscope consists of a centrally located 
0.1 mm single fiber for laser treatment and its surrounding about 9,000 (5 
m/piece) fibers for diagnosis. This system enables transmission of an image and 50 W Yb: fiber laser in parallel. By applying our fiberscope to laser treatment in various medical fields, it enables acquisition of an image, laser treatment, blood flow measurement, estimate of distance only in one fiberscope. By using this device for the PDT treatments applied to such as lung and cervical cancers, we expect to spot the irradiated area selectively while looking at a lesion. In this paper, we present a composition of minimally invasive laser therapy device using 1 mm composite-type optical fiberscope, the basics performance experiment result and an application to PDT therapy.
Saito, Hiroyuki; Machida, Akihiko; Katayama, Yoshinori; Aoki, Katsutoshi
no journal, ,
Tago, Takanori; Nagasawa, Naotsugu; Taguchi, Mitsumasa; Tamada, Masao; Kudo, Hisaaki*; Katsumura, Yosuke*
no journal, ,
Poly (L-lactic acid) (PLA) derived from corn starch is now widespread with a potential to replace the conventional petroleum-derived plastics. The PLA has, however, the less thermal stability above around 60C and impact resistance at room temperature than the conventional plastics. In this study, to improve the above-mentioned two properties of PLA, we investigated a new combination method of blending with polyamide11 (PA11) having high impact resistance, which is derived from castor oil, and then crosslinking. PLA/PA11(50/50wt%) blend with 3 phr of crosslinker irradiated to 100 kGy was formed about 80% of gel content. This sample demonstrated very little deformation above the grass transition-temperature of PLA, the melting-temperature of PLA and PA11 (ca.175C and 185C, respectively) by thermal-mechanical analysis. The impact value of crosslinked PLA/PA11 blend is 4.8 kJ/m. This value showed higher about 2.5 times of original PLA. Therefore, the applications of bioplastics will be expanded.
Oka, Toshitaka; Yokoya, Akinari; Fujii, Kentaro; Fukuda, Yoshihiro; Ukai, Masatoshi*
no journal, ,
In order to clarify the physicochemical mechanism of DNA damage induction due to the excitation/ionization of inner-shell electron in DNA constituent atoms, we have developed an X-band EPR spectrometer system at a synchrotron soft X-ray beamline (BL23SU) in SPring-8. In the present work, we obtained the "in situ" EPR spectra of thymine, cytosine and DNA in XANES regions around K-edge of oxygen and nitrogen during the soft X-ray irradiation. The soft X-ray energy dependence of the spin concentration of nucleobase films show similar fine structures to the XANES spectra. However, the short-lived EPR signal intensity of the DNA significantly increases above the oxygen K-shell ionizing threshold energy. These results suggest that the induction processes of the unpaired electron are different for a DNA molecule and particular nucleobases. The hydrated water which strongly bond to the DNA exists even in vacuum may be plays an important role in the induction of unpaired electron.