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Abstract: Fluorescence spectra were obtained in situ as a function of temperature (ranging from room temperature to 956K) from a melt of EuCl3 and LiCl. Three different characteristic Eu2+ fluorescence bands, associated with phase changes, were observed. The critical fluorescence dependence on temperature appearing in the blue fluorescence were resulted from the radiative relaxation from 4f65d1 excited state to 4f7 (8S7/2) ground state of Eu2+, which was reduced from Eu3+ of EuCl3 at high temperature. The fluorescence studies could provide information regarding the phase changes estimated as the stable dihalide, aggregation, and precipitation states of Eu2+ in alkali halide not only crystallic but also fluidic melting matrix. [Copyright &y& Elsevier]

Abstract: Photoionization detector (PID) was developed for a sensitive on-site detection of trace amounts of volatile organic compounds (VOCs) based on an annular type ion collection electrode assembly. An ion collector with an annular geometry could detect more stable ion signals in the PID system when compared to the other types of ion collectors when an UV lamp of 10.6eV was used as an ionization source. In order to enhance the detection sensitivity, a pre-concentration system, which was developed by adopting a ceramic heater packed with rod shaped molecular sieves, was adopted for a detection of VOCs. The adopted ceramic heaters had a resistance of 10–20Ohm, and the temperature of the heater was optimized by controlling the heating time of the resistor. The enhancement of the detection sensitivity was found to be 8–10 times with the PID system when compared to the signals measured without a pre-concentrator. The overall detection sensitivity of the developed PID system was estimated as 10ppb or better. [Copyright &y& Elsevier]

Abstract: The fluorescence of EuCl3 in LiCl–KCl eutectic melt according to temperature changes was investigated, and the spontaneous partial reduction of Eu3+ to Eu2+ at high temperature was confirmed by the fluorescence results. The fluorescence decreases when the temperature increases, and this was examined in detail. The studies of fluorescence provided information regarding the chemical and physical behavior of europium ions in the molten salt according to the temperature changes. It is applicable for monitoring species and concentrations and estimating the approximate chemical structure of the ions in molten salts. [ABSTRACT FROM AUTHOR]

Abstract: The content of plutonium isotopes in high burnup pressurized water reactor fuel samples was examined using both alpha spectrometry and mass spectrometry after anion exchange separation. The measured values were compared with results calculated by the ORIGEN-2 code. On average, the ratios (m/c) of the measured values (m) over the calculated values (c) were 1.22±0.16 for 238Pu, 1.02±0.14 for 239Pu, 1.08±0.06 for 240Pu, 1.06±0.16 for 241Pu, and 1.13±0.08 for 242Pu. Using the Pu data obtained in this work, correlations were derived between the alpha activity ratios of 238Pu/(239Pu+240Pu), the alpha specific activities of Pu, and the atom % abundances of the Pu isotopes. Using these correlations, the atom % abundances of the plutonium isotopes in the target samples were calculated. These calculated results agreed within a range from 2 to 8% of the experimentally derived values according to the isotopes of plutonium. [Copyright &y& Elsevier]

Abstract: An X-ray scattering method is presented for determining the thickness of an organic film placed on a steel substrate. The strong peaks of characteristic X-rays are taken as an advantage to measure the intensity of backscattered photons. It is shown that the intensity of Compton scattering of characteristic X-rays is proportional to film thickness, up to the thickness of 250μm of acrylic adhesive layers. In addition, the measurement time was 300ms, providing a simple and convenient method for on-line for thickness monitoring. [Copyright &y& Elsevier]

Abstract: Correlations among the alpha activity ratios of 238Pu/(239Pu+240Pu), the alpha specific activities of Pu and the atom % abundances of Pu isotopes were derived for the plutonium samples obtained from high burnup fuel samples from pressurized water reactors. Using the alpha activity ratios of 238Pu/(239Pu+240Pu) determined by alpha spectrometry, the alpha specific activities of Pu as well as the atom % abundances of the plutonium isotopes in the unknown samples were calculated without depending on mass spectrometry. The calculated alpha specific activities of Pu agreed with those determined by experiment within 2%, and the atom % abundances of the Pu isotopes agreed within 4% for 238Pu, 5% for 239Pu, 7% for 240Pu and 5% for 242Pu, respectively. In addition, an attempt was made to elucidate a correlation between the fuel burnup and the alpha activity ratio of 238Pu/(239Pu+240Pu) at a range of the burnup from 35.5 to 62.9 GWd/MtU. [Copyright &y& Elsevier]

Abstract: Cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were employed to investigate the electrodeposition of Eu and Al in an LiCl–KCl eutectic melt containing Eu2+ and Al3+ at 450°C. In order to deposit a pure Eu and Al alloy, the stoichiometrically lower concentration of Al3+ than that of Eu2+ and Al wires as a counter electrode was introduced into the bath of LiCl–KCl melt for the electrodeposition. The electrodeposition takes place at a potential more negative than −1.95V vs. Ag|Ag+ while the deposit is oxidized at more positive potential than −1.92V. Two new reduction peaks and an anodic peak on a W working electrode were observed at −2.39V, −2.42V, and −2.1V, vs. Ag|Ag+, respectively, suggesting that the potential window of the Al system in LiCl–KCl melt can be extended to −2.43V vs. Ag|Ag+. The EDS analysis indicated that AlEu can be deposited at the potential more negative than −2.37V. [Copyright &y& Elsevier]

Abstract: The effects of calcination time, calcination temperature, particle size of the precursor precipitate, and Li2O doping on interactions within a mixed Fe(III)–Ni(II) hydroxide precipitate were investigated using thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (XRD). The results indicated that neither the reaction time nor the particle size influenced the formation of nickel ferrite. It was found that the Fe(III) hydroxides participated in solid–solid interactions with the Ni(II) hydroxides to yield nickel ferrite at temperatures above 290°C. Increasing the percentage of Li2O dopant reduced the rate of nickel ferrite formation but increased that of nickel oxide formation, regardless of the calcination temperature between 400 and 700°C. These phenomena may be ascribed to the inhibition of crystallization of α-Fe2O3 by the substitution of some Li+ ions into Fe2O3 lattice structure. [Copyright &y& Elsevier]

Abstract: Data from the elemental composition-ratios and experimental prompt gamma spectra of samples were used to develop suitable discriminant classes for suspect samples. The collected data and gamma spectra were applied to principal component analysis (PCA) to discriminate explosives from non-explosive materials. [Copyright &y& Elsevier]