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Journal Articles

Influence of hydrofluoric acid on extraction of thorium using a commercially available extraction chromatographic resin

Fujiwara, Asako; Hoshi, Akiko; Kameo, Yutaka; Nakashima, Mikio

Journal of Chromatography A, 1216(18), p.4125 - 4127, 2009/03

 Times Cited Count:10 Percentile:31.87(Biochemical Research Methods)

Dependence of Th recovery on HF concentration in nitric acid solutions (1$$sim$$5 mol/dm$$^{3}$$) containing 1$$times$$10$$^{-6}$$ mol/dm$$^{3}$$ of Th and various concentrations of HF was studied using a commercially available UTEVA resin column (for uranium and tetravalent actinide). Thorium recovery decreased with an increase in the HF concentration in the sample solutions. The concentration of HF at which Th recovery started to decrease was about 1$$times$$10$$^{-4}$$ mol/dm$$^{3}$$ in 1 mol/dm$$^{3}$$ HNO$$_{3}$$ solution, about 1$$times$$10$$^{-3}$$ mol/dm$$^{3}$$ in 3 mol/dm$$^{3}$$ HNO$$_{3}$$ solution, and about 1$$times$$10$$^{-2}$$ mol/dm$$^{3}$$ in 5 mol/dm$$^{3}$$ HNO$$_{3}$$ solution. When Al(NO$$_{3}$$)$$_{3}$$ (0.2 mol/dm$$^{3}$$) or Fe(NO$$_{3}$$)$$_{3}$$ (0.6 mol/dm$$^{3}$$) was added as a masking agent for F$$^{-}$$ into the Th solution containing 1$$times$$10$$^{-1}$$ mol/dm$$^{3}$$ HF and 1 mol/dm$$^{3}$$ HNO$$_{3}$$, the Th recovery improved from 1.4$$pm$$0.3% to 95$$pm$$5% or 93$$pm$$3%. Effective extraction of Th on UTEVA resin was achieved by selecting the concentration of HNO$$_{3}$$ and/or adding masking agents such as Al(NO$$_{3}$$)$$_{3}$$ according to the concentration of HF in the sample solution.

Journal Articles

Rapid separation of alpha-emitting nuclides in radioactive waste

Hoshi, Akiko; Watanabe, Koichi; Fujiwara, Asako; Haraga, Tomoko; Kameo, Yutaka; Nakashima, Mikio; Takebe, Shinichi

Nihon Genshiryoku Gakkai Wabun Rombunshi, 7(3), p.177 - 185, 2008/09

The simple and rapid separation method was developed for actinides in the low-level radioactive waste. Extraction chromatographic columns were used for the separation of U, Np, Pu, Am, and Cm in the solution of the simulated solidified product and the simulated waste solution. In the investigation of separation procedure, it was tried to construct the scheme with the relatively non-corrosive reagents aiming to apply to the routine analysis of the radioactive waste. Recoveries and decontamination factors of actinides in the solution of simulated waste were high enough to determine of actinides in radioactive waste by alpha-spectrometry, mass spectroscopy. The time required of the separation operation was 2-3 hours. The chromatographic method was applied to analysis of actinide in actual waste solution, high recoveries and decontamination factors were obtained, which indicated that the extraction chromatographic separation method would be adopted as a simple and rapid separation method of actinide in waste.

Journal Articles

Instrumental design of indirect geometry crystal analyzer spectrometer; DNA at J-PARC

Shibata, Kaoru; Takahashi, Nobuaki; Nakagawa, Hiroshi; Fujiwara, Satoru; Kataoka, Mikio; Sato, Taku*; Kawakita, Yukinobu*; Tsukushi, Itaru*

Nihon Kessho Gakkai-Shi, 50(1), p.46 - 50, 2008/02

The instrumental design of an indirect geometry crystal analyzer spectrometer: DNA which is scheduled to be constructed in the Material and Life Science experimental Facility (MLF) at J-PARC, is reported in this article. This spectrometer is mainly aimed at searching for the high quality inelastic scattering spectra with only several mg order biomolecular sample in the plenty of wide range of energy and momentum transfers.

Journal Articles

Rapid determination of $$^{89}$$Sr and $$^{90}$$Sr in radioactive waste using Sr extraction disk and beta-ray spectrometer

Kameo, Yutaka; Katayama, Atsushi; Fujiwara, Asako; Haraga, Tomoko; Nakashima, Mikio

Journal of Radioanalytical and Nuclear Chemistry, 274(1), p.71 - 78, 2007/10

 Times Cited Count:21 Percentile:78.28(Chemistry, Analytical)

no abstracts in English

Journal Articles

Analysis of tritium of clearance level in concrete

Fujiwara, Asako; Kameo, Yutaka; Katayama, Atsushi; Nakashima, Mikio

Nihon Genshiryoku Gakkai Wabun Rombunshi, 6(1), p.58 - 64, 2007/03

no abstracts in English

Journal Articles

Evaluation of creep properties of reduced activation ferritic steels

Nakata, Toshiya; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Komazaki, Shinichi*; Fujiwara, Mikio*; Kono, Yutaka*; Koyama, Akira*

Nihon Kinzoku Gakkai-Shi, 71(2), p.239 - 243, 2007/02

 Times Cited Count:4 Percentile:33.15(Metallurgy & Metallurgical Engineering)

no abstracts in English

Journal Articles

Application of extraction chromatography to the separation of thorium and uranium dissolved in a solution of high salt concentration

Fujiwara, Asako; Kameo, Yutaka; Hoshi, Akiko; Haraga, Tomoko; Nakashima, Mikio

Journal of Chromatography A, 1140(1-2), p.163 - 167, 2007/01

 Times Cited Count:23 Percentile:55.93(Biochemical Research Methods)

Extraction chromatography with UTEVA resin was applied to separation of Th and U from control solutions prepared from a multi-element control solution and from sample solutions of solidified simulated waste. Thorium and U in control solutions with 1 to 5 M HNO$$_{3}$$ were extracted with UTEVA resin and recovered with a solution containing 0.1 M HNO$$_{3}$$ and 0.05 M oxalic acid to be separated from the other metallic elements. Extraction behavior of U in the sample solutions was similar to that in the control solutions, but extraction of Th was dependent on the concentration of HNO$$_{3}$$. Thorium was extracted from 5 M HNO$$_{3}$$ sample solutions but not from 1 M HNO$$_{3}$$ sample solutions. We conjecture that thorium fluoride formation interferes with extraction of Th. Addition of Al(NO$$_{3}$$)$$_{3}$$ and Fe(NO$$_{3}$$)$$_{3}$$, which have a higher stability constant with fluoride ion than Th does with it improved extractability of Th from 1 M HNO$$_{3}$$ sample solution.

Journal Articles

A Simple radioactivity determination technique by alpha-ray spectrometry for homogenous thick sample

Kameo, Yutaka; Fujiwara, Asako; Watanabe, Koichi; Kono, Nobuaki; Nakashima, Mikio

Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(3), p.187 - 193, 2005/09

no abstracts in English

Oral presentation

Analysis of Am-242m in solidified products

Fujiwara, Asako; Kameo, Yutaka; Haraga, Tomoko; Nakashima, Mikio

no journal, , 

no abstracts in English

Oral presentation

Application of UTEVA resin cartridge to separate Th and U in solidified products of low-level radioactive waste

Fujiwara, Asako; Kameo, Yutaka; Nakashima, Mikio

no journal, , 

Separation of Th and U in dissolved solution of solidified products of simulated waste with UTEVA resin has been investigated. Thorium and U were separated from the other elements such as Na, Al, Ca, Fe by column chromatography with UTEVA resin and recovered with the solution containing 0.1 M HNO$$_{3}$$ and 0.05 M oxalic acid. The concentration of Am and Pu in the fraction to recover Th and U was under the detection limit. Although 1% of Np was contaminated to the recovery fraction of Th and U, Np would not interfere the measurement of U. UTEVA resin cartridge system with flow pomp was applied to the separation of Th and U. The result from cartridge system showed good separation of Th and U from Na, Al, Ca, and Fe. The flow rate with cartridge system was 4-5 times faster than that with column system to shorten the operation time.

Oral presentation

Effect of F$$^{-}$$ on Th extraction with UTEVA resin

Fujiwara, Asako; Kameo, Yutaka; Nakashima, Mikio

no journal, , 

no abstracts in English

Oral presentation

Effects of sugars on the structures and dynamics of lipid membranes

Masui, Tomomi; Fujiwara, Satoru; Nakagawa, Hiroshi; Kataoka, Mikio

no journal, , 

Keeping cells in aqueous environment is essential for organisms to be alive. Desiccation damages the cells severely, and causes death of most organisms. Some organisms, however, known to survive under such arid conditions. This desiccation tolerance has been known to be related to the production of sugars in these organisms. In this study, we investigate the effect of trehalose on the structure and dynamics of lipid membranes in the solution condition by employing small and wide angle X-ray scattering and neutron spin echo technique. These experimental data represent the trehalose disorder the lamellar structure and decrease the bending rigidity of membrane.

Oral presentation

Effects of trehalose on the structures and dynamics of lipid membranes

Masui, Tomomi; Fujiwara, Satoru; Nakagawa, Hiroshi; Kataoka, Mikio

no journal, , 

It is known that trehalose is a protective reagent and plays important roles in desiccation tolerance. One of the important properties of trehalose for the desiccation tolerance is stabilization of the biomembranes in the fluid phase. However, due to lack of information of how the trehalose molecules distribute on the biomembrane and interact with lipid molecules, the preservation mechanism of the biomembrane by trehalose has not been elucidated. Here we aimed at determining the distribution of trehalose on the simple model biomembrane and characterize dynamic properties of the membrane and the lipid molecules. For this purpose we employed small- and wide-angle X-ray scattering (SAXS and WAXS) and neutron spin echo (NSE) techniques. The NSE measurement revealed that the addition of trehalose to lipid membrane decreases the bending rigidity. This effect of trehalose is same tendency of temperature.

Oral presentation

Effect of trehalose on the structure and dynamics of lipid membranes

Masui, Tomomi; Fujiwara, Satoru; Endo, Hitoshi; Nakagawa, Hiroshi; Kataoka, Mikio

no journal, , 

Water is essential for organisms and desiccation damages the cells severely, and causes death of most organisms. Some organisms, however, known to survive under such arid conditions. This desiccation tolerance has been known to be related to the production of sugars in these organisms. One property which is important for the desiccation tolerance is stabilization of the cell membranes in the fluid phase by limiting the dehydration-induced increase in the gel-fluid transition temperature of the membranes. The membranes not only act as a barrier within or around a cell, but also control transfer of substances across the membranes. Elucidating how sugars interact with the membranes is therefore important for understanding the molecular mechanism of the desiccation tolerance. We investigated the effects of the sugars on the structures and the dynamics of the lipid membranes by small- and wide-angle X-ray scattering (SAXS and WAXS), and neutron spin-echo (NSE), techniques.

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