In order to reveal the reactivity of toluenethiols, the hydrogen isotope exchange reaction between one of three toluenethiols (o–,m–, andp–) and poly (vinyl alcohol) labeled with tritium was observed at 50 90°C. The reaction was analyzed with both the data obtained and theA
-McKay plot method, and the following has been quantitatively clarified: (1) the reactivity order of toluenethiols is (o–>(m–)>(p–); (2) the temperature dependences of the reactivity of toluenethiols are nearly equal; (3) the reactivity of benzenethiol is considerably decreased by the CH3 group bonded to the ortho position.
Time resolved Mössbauer spectra were measured for57Co-labelled Co/IO3/2 using a delayed coincidence technique. A life-time for unstable57Fe(II)-species formed through EC-decay was estimated to be 43±5 ns at room temperature and the initial distribution of57Fe(II)/57Fe(III) at 14.4 keV nuclear level to be 0.47±0.13. The results are discussed in terms of electron transfer from the decayed57Fe(II) atoms to iodate ions.
Reaction products of ferrocenophane with CF3COOH, CCl3COOH, CF3SO3H and SbCl5 were prepared. Mössbauer spectroscopic data and magnetic susceptibility measurements suggest the bond formation of Fe–H+ and Fe–Cl+, in which iron atoms are in a high-spin Fe/II/state.
Authors:T. Fujii, H. Yamana, M. Watanabe, and H. Moriyama
Extraction behaviors of Pd(II) in the TRUEX and PUREX solvent extractions were studied by using octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide. The effect of scrubbing in the TRUEX solvent extraction was demonstrated by adding oxalic acid. The distribution ratios of palladium (DPd's) in the diluted region of [HNO3] were found to depend strongly on the fraction of cationic species, Pd(NO3)+, existed in the aqueous phase. The gradual decrease of DPd with the increase of acidity beyond [H+] 1 mol·dm-3 was controlled by the formation of the anionic species Pd(NO3)3-.
Authors:T. Fujii, H. Yamana, K. Takamiya, M. Watanabe, and H. Moriyama
Adsorption behavior of fission products in nitric acid solution on various alloys and metals was studied by using a multitracer produced by neutron irradiation of UO2. The adsorption behavior of the fission products 99Mo, 131I, 132Te, 140La, and 143Ce, and 239Np was simultaneously studied. Some chemical decontamination tests were also examined. Clear adsorption of 99Mo, 131I, and 132Te was observed, whereas adsorption of 140La, 143Ce, and 239Np was not. The adsorption characteristics were discussed by considering anion-exchange reaction and surface complexation.
Authors:Y. Watanabe, M. Nakada, K. Endo, H. Nakahara, and H. Sano
KX-ray-gated emission Mössbauer spectra of57Co-labelled CoF2 and CoF2.2H2O were measured at room temperature, using the coincidence technique. A difference was found in the relative intensity of57Fe(II)/57Fe(III) between the X-ray-gated and non-gated emission spectra. The results are explained in terms of local radiolytic effects of water of crystallization and the chemical effects associated with the de-excitation processes caused by EC-decay.
Authors:T. Omori, K. Nagasaki, E. Watanabe, and H. Suganuma
A new spectrophotometric determination of technetium has been developed by means of the solvent extraction of tris(1,10-phenanthroline)iron(II) ([Fe(phen)32+]) with pertechnetate into nitrobenzene. The concentration of technetium can be determined by measuring the characteristic absorbance at 516 nm (=11,700M–1·cm–1) in the organic phase. An important feature of the proposed method is that the concentration of pertechnetate can be determined without complicated processes such as the reduction of pertechnetate and the subsequent formation of a colored chelate.
Authors:T. Tsuji, Y. Yamamura, H. Watanabe, K. Saito, and M. Sorai
The heat capacities and magnetic susceptibilities of powdered samples of FexNbS2 (x=0.14, 0.21 and 0.30) were measured at temperatures from 8 to 303 K and from 5 to 300 K, respectively. For Fe0.14NbS2, the magnetic susceptibility exhibited an anomaly as a shoulder at about 57 K, but no heat capacity anomaly was observed at this temperature, indicating the appearance of a spin-glass state. Anomalies in the heat capacity for FexNbS2 (x=0.21 and 0.30) occurred at 100.5 and 45.0 K, respectively, where the magnetic susceptibility displayed a maximum, corresponding to an antiferro-paramagnetic phase transition. The electronic state of the iron atom is discussed on the basis of entropy analysis.
Authors:T. Kambara, J. Suzuki, H. Yoshioka, and Y. Watanabe
Radiometric titration of antimony(III) with potassium bromate in hydrochloric acid media using the standard series method
provided much valuable informations on the titration errors which depended on the concentrations of the acid and antimony(III).
The hydrochloric acid concentrations between 2.5 and 3.0M were found to be optimum for the oxidation of antimony(III) amounts
of 4 μg or less. Under these optimum reaction conditions the redox substoichiometric isotope dilution analysis was applied
to the determination of antimony in metallic zinc and the satisfactory results were obtained, without the separation of matrix
element. Also, the merits of various oxidizing agents hitherto studied for the quantitative oxidation of antimony(III) were
compared and discussed.
Authors:T. Watanabe, G. Zhang, H. Yoshida, and T. Kawai
The miscibility of crystalline syndiotactic polystyrene (SPS)/non-crystalline atactic polystyrene (APS) blend was estimated
by the crystallization dynamics method, which evaluated the nucleation rate, the crystal growth rate and the surface free
energy parameter. The melting temperature depression suggested that SPS/APS blends were the miscible system but not in molecular
level. The relationship between the blend content and the chemical potential difference evaluated at a constant crystal growth
rate showed a good linear relationship. These facts suggested that SPS/APS blends contained the concentration fluctuation
with the size between few nm to less than 80 nm.