JOPSS - Search Results

To estimate the polyelectrolyte effect and the effect of the heterogeneous composition of humic acids, the complex formation constants of Eu(III) and Ca(II) with Aldrich humic acid and polyacrylic acid were obtained, for Eu(10 $^{-8}$ to 10 $^{-5}$ M) by solvent extraction with TTA and TBP in xylene, for Ca (10 $^{-10}$ M) with TTA and TOPO in cyclohexane and for Ca(10 $^{-4}$ M) by using ion-selective electrode. By defining the apparent formation as $beta_{alpha}$ = [MR $_{m}$ ]/([M][R]), where [R] denotes the concentration of dissociated functional group, [M] and [MR $_{m}$ ] denote the concentration of free and bound metal ion and pcH is defined as-log[H], the values of log $beta_{alpha}$ have been obtained at pcH 4.8 - 5.5 in 0.1 - 1.0M NaClO $_{4}$ and NaCl. Log $beta_{alpha}$ of Eu-humate varied from 5.0 to 9.3 and that of Ca-humate from 2.0 to 3.4..For both humate and polyacrylate, log $beta_{alpha}$ increased with pcH or with the degree of dissociation. The increase in the ionic strength O.1 to 1.0 M decreased the log $beta_{alpha}$ , the decrease in log $beta_{alpha}$ of Eu(III)-humate is 1.6, that of Eu(III), polyacrylate 0.7, that of Ca(II)-humate 1.9 and that of Ca(II)-polyacrylate 1.2. While the increase in the metal ion produced no effect on log $beta_{alpha}$ of polyacrylate, log $beta_{alpha}$ of humate decreased. Depending on the concentration of Eu(III), the coexistence of Ca(II) reduced log $beta_{alpha}$ of humate by 0 to 0.8. The dependence of log $beta_{alpha}$ of humate on the metal ion concentration suggests the coexistence of strong and weak binding sites in the hmnic acid.

Journal Articles

Preparation and characteristics of chitosan-containing gels by -irradiation

Yoshida, Masaru; Hendri, J.*; Maekawa, Yasunari; Kume, Tamikazu; Katakai, Ryoichi*; Said, A. E. A.; Hegazy, E. A.

Chitin and Chitosan; Chitin and Chitosan in Life Science, p.43 - 46, 2000/00

no abstracts in English

Journal Articles

Speciation of europium(III) sorbed on a montmorillonite surface in the presence of polycarboxylic acid by laser-induced fluorescence spectroscopy

Takahashi, Yoshio*; Kimura, Takaumi; Kato, Yoshiharu; Minai, Yoshitaka*

Environmental Science & Technology, 33(22), p.4016 - 4021, 1999/00

https://doi.org/10.1021/es990037n

Times Cited Count：46 Percentile：74.45(Engineering, Environmental)

no abstracts in English

Journal Articles

Laser-induced fluorescence study on the interaction of Eu(III) with polycarboxylates

Takahashi, Yoshio*; Kimura, Takaumi; Kato, Yoshiharu; *; *; *

Journal of Radioanalytical and Nuclear Chemistry, 239(2), p.335 - 340, 1999/00

https://doi.org/10.1007/BF02349507

Times Cited Count：15 Percentile：72.26(Chemistry, Analytical)

no abstracts in English

JAEA Reports

Fabrication of tubed functionally graded material by slurry dipping process

Watanabe, Ryuzo*

PNC TJ9601 98-005, 85 Pages, 1998/03

PNC-TJ9601-98-005.pdf:2.07MB

To fabricate a long life fuel cladding tubes for the fast breeder reactor, the concept of functionally graded material was applied for the material combination of molybdenum/stainless steel/ titanium, in which titanium is placed at the inner side to withstand against fission products and neutron irradiation, and molybdenum at the outer side to withstand corrosion by liquid sodium coolant. Slurry dipping method was employed for the processing because of its capability of shape forming and microstructural control. The graded layers of titanium and molybdenum were formed on both sides of stainless steel substrate according to an optimum composition profile for the thermal stress reduction. Such graded layers were successfully formed by slurry dipping. Dispersion, sedimentation, viscosity, rheology, as well as yield value, of the slurries were investigated in detail inconnection with properties of dispersion medium, dispersion reagent, binder and raw powders. Low- and high-viscosity slurries were investigated to enlarge a possibility of film thickness control. For the low-viscosity slurry it is necessary to suppress the sedimentation of dispersion particles, while for the high-viscosity slurry it turned out to be important to clarify the flow characteristics of the slurry for the determination of the yield value, which is needed for the precise control of the dip-coated layer thickness. The forming conditions were determined for the low-viscosity slurry in taking sedimentation rate and sedimentation height as measures of slurry stability and dispersion, respectively. It was confirmed that slow sedimentation and low sedimentation height gave reproducible film forming. The high-viscosity slurry was free from sedimentation, and the control of the film thickness with viscosity and yield value was rather easier. The consolidation Process of the dip-coated layer, including drying and debinding, followed conventional powder metallurgical techniques, with particular ...

JAEA Reports