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Shimizu, Takeshi*; Wang, H.*; Tanifuji, Naoki*; Matsumura, Daiju; Yoshimura, Masashi*; Nakanishi, Koji*; Ota, Toshiaki*; Yoshikawa, Hirofumi*
Chemistry Letters, 47(5), p.678 - 681, 2018/05
Times Cited Count：9 Percentile：33.47(Chemistry, Multidisciplinary)Nishi, Toshiaki*; Sasaki, Takuo; Ikeda, Kazuma*; Suzuki, Hidetoshi*; Takahashi, Masamitsu; Shimomura, Kenichi*; Kojima, Nobuaki*; Oshita, Yoshio*; Yamaguchi, Masafumi*
AIP Conference Proceedings 1556, p.14 - 17, 2013/09
Times Cited Count：0 Percentile：0.01(Energy & Fuels)Koma, Yoshikazu; Ashida, Takashi; Meguro, Yoshihiro; Miyamoto, Yasuaki; Sasaki, Toshiki; Yamagishi, Isao; Kameo, Yutaka; Terada, Atsuhiko; Hiyama, Toshiaki; Koyama, Tomozo; et al.
Proceedings of International Nuclear Fuel Cycle Conference; Nuclear Energy at a Crossroads (GLOBAL 2013) (CD-ROM), p.736 - 743, 2013/09
Fukushima Daiichi Nuclear Power Station (F1NPS), TEPCO, was severely damaged with the hydrogen explosions caused by losing their cooling functions due to the earthquake and the tsunami occurred on March 11, 2011. Radioactive wastes generated from the current FINPS and future their decommission and demolition are greater huge amount than those from general reactors and nuclear fuel facilities. Toward accomplishing safe and reasonable management of the wastes, great effort of R&Ds has been strongly required and performed in bringing together the knowledge and experience of all of Japan. This report outlines the current status of the R&Ds performed in JAEA.
O
Kirishima, Akira*; Mitsugashira, Toshiaki*; Onishi, Takashi; Sato, Nobuaki*
Journal of Nuclear Science and Technology, 48(6), p.958 - 966, 2011/06
Times Cited Count：3 Percentile：25.9(Nuclear Science & Technology)A novel reprocessing process based on the selective sulfurization of fission products (FP) has been proposed, where FP and minor actinides (MA) are first sulfurized by CS
gas, and then, dissolved by a dilute nitric acid solution. Consequently, the fuel elements are recovered as UO and PuO. As a basic research of this new concept, the sulfurization and dissolution behaviors of U, Pu, Np, Am, Eu, Cs and Sr were investigated in this paper using 
Pu, 
Np, 
Am, 
Eu, 
Cs and 
Sr doped UO sample by 
ray and 
spectrometries. The dependence of the dissolution ratio of each element on the sulfurization temperature was studied and reasonably explained by combining the information of the sulfide phase analysis and the chemical thermodynamics of the dissolution reaction. The sulfurization temperature ranging from 350 to 450 
C seems to be promising for the separation of FP and MA from U and Pu.
collisions at 
= 200 and 62.4 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count：184 Percentile：99.45(Physics, Nuclear)Transverse momentum distributions and yields for 
, and 
in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as 
and 
scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Eto, Takeharu*; Son, D.*; Akino, Toshiaki*; Akino, Toshiro*; Nishi, Kenji*; Kureta, Masatoshi; Arai, Masatoshi
Sensors (Internet), 10(4), p.4100 - 4113, 2010/04
Times Cited Count：8 Percentile：45.65(Chemistry, Analytical)Accumulation and averaging of data is a standard technique applied to processing data with low signal-to-noise ratios (SNR), such as image signals captured in ultra-high-speed imaging. The authors propose an architecture layout of an ultra-high-speed image sensor capable of on-chip signal accumulation. The very high frame rate is enabled by employing an image sensor structure with a multi-folded CCD in each pixel which serves as in-situ image signal storage. The signal accumulation function is achieved by direct connection of the first and the last storage elements of the in-situ storage CCD. The in-situ storage image sensor with the signal accumulation function is named as Image Signal Accumulation Sensor (ISAS).
Iwai, Yasunori; Hiroki, Akihiro; Yagi, Toshiaki*; Tamada, Masao; Yamanishi, Toshihiko
Fusion Engineering and Design, 83(10-12), p.1410 - 1413, 2008/12
Times Cited Count：7 Percentile：44.46(Nuclear Science & Technology)The radiation durability of the solid-polymer-electrolyte (SPE) water electrolyzer composed of the Water Detritiation System (WDS) was investigated. A series of -ray and electron beam irradiation tests of Nafion N117 ion exchange membrane, a key polymer in a SPE electrolyzer, beyond ITER-WDS requirement (530kGy) indicated Nafion N117 has enough radiation durability up to 1600 kGy from the view points of mechanical strength and ion exchange capacity. To keep electrolysis function of a SPE cell up to 530 kGy, we suggest replacing Teflon with polyimide. A series of -ray irradiation test of Kapton polyimide observed no serious damage in strength up to 1500 kGy. Concerning rubber material for O-ring seal, we observed that soaking VITON rubber keeps the constant value of tensile strength up to 1500 kGy. Moreover organic elution was not observed from a soak of VITON. From the viewpoint of stable strength and organic elution, VITON is a first candidate for rubber material.
-ray irradiationFurusawa, Kazuya*; Kita, Erika*; Saeki, Toshihiko*; Nagasawa, Naotsugu; Nishi, Norio*; Dobashi, Toshiaki*
Journal of Biomaterials Science; Polymer Edition, 19(9), p.1159 - 1170, 2008/09
To insolubilize DNA for preparing a novel carcinogen adsorbent, effects of -ray irradiation on aqueous solutions of mixtures of DNA with cross-linking biopolymers (CBP): gelatin, bovine serum albumin, carboxymethyl cellulose and hydroxyethyl-cellulose, O-[2-hydroxy-3-(trimethyl ammonio)-propyl], chloride have been studied. DNA-CBP hybrid gels were successfully prepared from aqueous mixtures of DNA with CBP in a limited range of irradiation dose. Gel fraction (Gf) and swelling ratio (S) of the hybrid gels were measured. The Gf and S of hybrid gels increased and decreased, respectively, with increasing irradiated dose. Adsorption of one of carcinogen, acridine orange, was also examined for the gels. From the experimental results, the optimum condition for preparing insolubilized homogeneous DNA gels was determined.
Iwai, Yasunori; Yamanishi, Toshihiko; Hiroki, Akihiro; Yagi, Toshiaki*; Tamada, Masao
Fusion Science and Technology, 54(2), p.458 - 461, 2008/08
Times Cited Count：6 Percentile：39.98(Nuclear Science & Technology)A solid-polymer-electrolyte (SPE) water electrolyzer for high-level tritiated water was designed for the Water Detritiation System (WDS). Polymeric materials were selected from a main viewpoint of radiation durability to keep their functions beyond ITER-WDS requirement (530 kGy). Our selection was Pt + Ir applied Nafion N117 ion exchange membrane, VITON O-ring seal and polyimide insulator. A g-ray irradiation test of the SPE cell demonstrated the durability of the cell against 530 kGy. The detritiation of the polymeric materials is a critical problem for the maintenance or for the disposal of the electrolyzer. As for the Nafion membrane, most of tritiated water in the membrane was rapidly removed by such as vacuum dehydration. It was difficult, by contrast, to remove bound tritiated water in the membrane. An effective method to remove tritiated water in the bound water is to promote an isotope exchange.
Nagasawa, Naotsugu; Luan, L. Q.*; Yagi, Toshiaki; Yoshii, Fumio; Kume, Tamikazu; Nakanishi, Tomoko*; Tamada, Masao
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 55, 2007/02
The sodium alginate was irradiated by -ray, and plant growth activity test and structural change of the product were studied. It was found that the concentration of 100 mg/L of alginate irradiated at 75 kGy in 4 % aqueous solution was the highest for plant growth. Separation of the degraded product was performed using ultrafiltration membranes and found that fraction with molecular weight in the range of 1-3 kDa (6-15 units) not only showed a remarkable effect on the plant growth, but also increased the activity of plant enzymes; 
. This fraction was stronger than one of the enzymatic degradation product. This differences proposed formation of carbonyl and carboxyl groups along with the main-chain scission.
Iwai, Yasunori; Yamanishi, Toshihiko; Isobe, Kanetsugu; Nishi, Masataka; Yagi, Toshiaki; Tamada, Masao
Fusion Engineering and Design, 81(1-7), p.815 - 820, 2006/02
Times Cited Count：15 Percentile：70.41(Nuclear Science & Technology)Solid-polymer-electrolyte (SPE) water electrolysis is attractive in electrolytic process of water detritiation system (WDS) in fusion reactors because it can electrolyze liquid waste directly, but radioactive durability of its ion exchange membrane is a key point. Radioactive durability of Nafion, a typical commercial ion exchange membrane, was experimentally investigated using Co-60 irradiation facility and electron beam irradiation facility at Takasaki Radiation Chemistry Research Establishment of JAERI. Nafion is composed of PTFE (Polytetrafluoroethylene) main chain. However the degradation of its mechanical strength by irradiation was significantly distinguished from that of PTFE and no serious damage was observed for its ion exchange capacity up to 530 kGy, the requirement of ITER. Atmospheric effects such as soaking and oxygen on degrading behaviors were discussed from the viewpoint of radical reaction mechanism. Dependencies of operating temperature and radioactive source are also demonstrated in detail.
Iwai, Yasunori; Yamanishi, Toshihiko; Nishi, Masataka; Yagi, Toshiaki; Tamada, Masao
Journal of Nuclear Science and Technology, 42(7), p.636 - 642, 2005/07
Times Cited Count：20 Percentile：77.47(Nuclear Science & Technology)Radioactive durability of organic polymers in solid-polymer-electrolyte water electrolyzer was investigated by -ray irradiation. Serious deteriorations for tensile strength and ion exchange capacity of ion exchange membrane (Nafion) were not observed up to 850 kGy. No serious damage was also observed for the gasket materials (Aflas) up to 500 kGy. PFA and FEP, insulator materials, lost their tensile strength at 300 kGy or less. As the result, it is concluded that the electrolyzer could be used up to around 500 kGy in the case where PFA and FEP are replaced by the polyimide resin whose durability is well demonstrated. Two degrading mechanisms were supposed. One is direct degradation by energy of radial rays. The other is that by the attack of radicals. It was demonstrated that the effect of radicals on the membrane was not dominant. The quantity of dissolved fluorine in water was found to correlate with the tensile strength and ion exchange capacity. Hence, it is possible to evaluate the degradation of the membrane by monitoring the quantity of dissolved fluorine.
Watanabe, Satoshi; Ishioka, Noriko; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; Kiyomiya, Shoichiro*; Nakanishi, Hiromi*; Mori, Satoshi*
Radiochimica Acta, 89(11-12), p.853 - 858, 2002/02
Times Cited Count：17 Percentile：74.75(Chemistry, Inorganic & Nuclear)no abstracts in English
C]methionine translocation in barley in relation to mugineic acid phytosiderophore biosynthesisBughio, N.*; Nakanishi, Hiromi*; Kiyomiya, Shoichiro*; Matsuhashi, Shimpei; Ishioka, Noriko; Watanabe, Satoshi; Uchida, Hiroshi*; Tsuji, Atsunori*; Osa, Akihiko; Kume, Tamikazu; et al.
Planta, 213(5), p.708 - 715, 2001/09
Times Cited Count：16 Percentile：36.74(Plant Sciences)[C]Methionine ([C]Met) was supplied through barley roots and the C signal was follwoed using a real-time imaging system (PETIS), with subsequent development of autoradiographic images of the whole plant. In all cases, [C]Met was first translocated to the discrimination center, and this part was strongly labeled. Met absorbed by roots of the plants was subsequently translocated to other parts of the plant. In Fe-deficient (-Fe) barley plants, a drastic reduction in [C]Met translocation from the roots to the shoot was observed, while a greater amount of C was found in the leaves of Fe-sufficient or Met-pretreated -Fe plants. Treatment of -Fe plants with amiooxyacetic acid increased the translocation of [C]Met to the shoot. The retention of exogenously supplied [C]Met in the roots of -Fe barley indicates that the Met is used in the biosynthesis of mugineic acid (MA) in barley roots. This and the absence of Met movement from shoots to the roots suggest that the MA phytosiderophores precursor Met originates in the roots of plants.
Mori, Satoshi*; Nakanishi, Tomoko*; Hayashi, Hiroaki*; Oyama, Takuji*; Uchida, Hiroshi*; Matsuhashi, Shimpei; Sekine, Toshiaki
Radioisotopes, 50(9), p.408 - 418, 2001/09
no abstracts in English
F-labeled water movement in a cowpea plant by positron emitting tracer imaging system (PETIS)Furukawa, Jun*; Yokota, Harumi*; Tanoi, Keitaro*; Ueoka, Shiori*; Matsuhashi, Shimpei; Ishioka, Noriko; Watanabe, Satoshi; Uchida, Hiroshi*; Tsuji, Atsunori*; Ito, Takehito*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 249(2), p.495 - 498, 2001/08
Times Cited Count：16 Percentile：73.13(Chemistry, Analytical)We present real time Vanadate (V
) uptake imaging in a cowpea plant by Positron Emitting Tracer Imaging System (PETIS). Vanadium-48 was produced by bombarding a Sc foil target with 50 MeV -particles at Takasaki Ion accelerators for Advanced Radiation Application (TIARA) AVF cyclotron. Then 
V was added to the culture solution to investigate the V distribution in a cowpea plant. The real time uptake of the V was monitored by PETIS. We measured the distribution of V in a whole plant after 3, 6 and 20 hours of V treatment by Bio-imaging Analyzer System (BAS). After the 20 hour treatment, vanadate was detected at the up-ground part of the plant. To know the effect of V uptake on plant activity, F-labeled water uptake was analyzed by PETIS. When a cowpea plant was treated with V for 20 hours before F-labeled water uptake experiment, the total amount of F-labeled water absorption was drastically desreased. Results suggest the inhibition of water uptake was mainly caused by the vanadate already moved to the up-ground part of the plant.
F used as tracer to study water uptake and transport imaging of a cowpea plantNakanishi, Tomoko*; Tanoi, Keitaro*; Yokota, Harumi*; Kang, D.-J.*; Ishii, Ryuichi*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Sekine, Toshiaki; Matsuhashi, Shimpei; et al.
Journal of Radioanalytical and Nuclear Chemistry, 249(2), p.503 - 507, 2001/08
We present the water uptake ability of cowpea (
) which has been regarded as one of the most drought resistant species among the pulse crops. It has been suggested that in the lower part of the stem, parenchymatous tissue for storing water had been developed for the function of deought resistance. We confirmed that in this tissue, water amount was high compared to the other stems by neutron radiography. Then the water uptake manner was measured by positron emitting tracer imaging system (PETIS) using F labeled water produced by a cyclotron. Comparing the water uptake manner of cowpea plant with that of common bean, cowpea plant was found to maintain high water uptake activity after drying treatment, suggesting the high drought resistant character.
O-labeled and F-labeled water uptake in a soybean plant by PETIS (Positron Emitting Tracer Imaging System)Nakanishi, Tomoko*; Yokota, Harumi*; Tanoi, Keitaro*; Ikeue, Natsuko*; Okuni, Yoko*; Furukawa, Jun*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Sekine, Toshiaki; et al.
Radioisotopes, 50(6), p.265 - 269, 2001/06
O-Labeled and F-Labeled water uptake manner in a soybean plant was compared by PETIS (Positron Emitting Tracer Imaging System). O-Labeled water (half-life: 2 min) and F-Labeled water (half-life: 110 min) were produced by a cyclotron by 
N(d,n)O and 
O(,pn)F reactions, respectively. A root of a soybean plant was cut off and each labeled water was supplied from the basal part of the plant. The gamma-rays emitted from the sample was measured by a BGO counter with a detection area of 5 cm
15 cm. The radioactivity from each stem was accumlated every 15 s till 20 min. It was found that F-labeled water was taken up much faster than O-labeled water, suggesting that in F-labeled water, fluorine was moved in the form of F-ion. When BAS image of O-labeled water in a plant after 5 min and 10 min of water supply was taken, it was found that the labeled water was observed only in the lowest internode, between a root and the first leaves.
O-water flow in tomato and rice in the light and dark using a positron-emitting tracer imaging system (PETIS)Mori, Satoshi*; Kiyomiya, Shoichiro*; Nakanishi, Hiromi*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Matsuhashi, Shimpei; Hashimoto, Shoji; Sekine, Toshiaki; Uchida, Hiroshi*; et al.
Soil Science and Plant Nutrition, 46(4), p.975 - 979, 2000/12
Times Cited Count：29 Percentile：57.23(Plant Sciences)no abstracts in English
C]methionine translocation in Fe-sufficient and Fe-deficient barley using a Positron Emitting Tracer Imaging System (PETIS)Nakanishi, Hiromi*; N.Bughio*; Matsuhashi, Shimpei; Ishioka, Noriko; Uchida, Hiroshi*; Tsuji, Atsunori*; Osa, Akihiko; Sekine, Toshiaki; Kume, Tamikazu; Mori, Satoshi*
Journal of Experimental Botany, 50(334), p.637 - 643, 1999/05
no abstracts in English
