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Abstract  

The incorporation mechanism of Cs+ ions from CsNO3 into NH4Zr2(PO4)3 was studied on a mixture of CsNO3 and NH4Zr2(PO4)3 by powder X-ray diffraction analysis and by monitoring off-gases released from the mixture upon heating with a thermogravimetry analyzer connected to an infrared spectrometer. With increasing temperature, the decomposition of CsNO3 first started, followed by the conversion of NH4Zr2(PO4)3 to HZr2(PO4)3 with the release of NH3. At around 500°C, the Cs Zr2(PO4)3 phase started to appear as a result of the H+/Cs+ ion exchange. No Cs+ ion loss was observed at thermal treatment temperatures of 900°C and lower.

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Abstract  

The concentrations of As(III) and As(V) in natural hot spring and river waters collected in the Kusatsu-Shirane volcano area, Gunma, Japan, were determined by neutron activation analysis (NAA) preceded by the pyrrolidinedithiocarbamate (PDC) coprecipitation. The PDC coprecipitation technique using Pb(PDC)2 as a collector of As(III) was applicable to the determination of As(III) at μg/L to mg/L levels. It was found important that the sufficient amount of PDC must be added to sample waters to accomplish the quantitative coprecipitation of As(III), taking the amounts of coexisting metal ions into consideration.

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Abstract  

Concentrations of arsenic and bromine dissolved in hot spring waters have been determined by neutron activation analysis using 0.5 cm3 of sample waters without any chemical pretreatment. The samples prepared for neutron irradiation were simply pieces of filter papers which were infiltrated with samples. With the results of satisfactorily high accuracy and precision, this analytical method was found to be very convenient for the determinations of arsenic and bromine dissolved in water at ppm to sub-ppm levels.

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Abstract  

A total of 19 elements in the samples of atmospheric deposition collected in Kawasaki, Japan, were determined by neutron activation analysis, ICPAES and flame photometry. The amounts of soil dust depositions were larger in springs and those of Sb and Zn depositions were larger in summers than in the other seasons. The values of the enrichment factors were higher for Sb and Zn than for the other elements determined throughout the sampling period. A factor analysis showed that the two elements were characterized as industrial components. Rubber products like tires that contain noncombustibles and rubber accelerators were a possible origin of high concentrations of Sb and Zn in the present samples.

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Abstract  

Concentration of lanthanides (Lns) in alunite group mineral samples from the Kusatsu-Shirane volcano area, Gunma, Japan, were determined by neutron activation analysis. Their Ln abundance patterns showed enrichment of light Lns relative to their original rocks and GSJ geochemical reference samples of feldspars. It was found that the concentration of light Lns increased with increasing concentration of K and P. The positive correlation between the light Lns and P concentration suggested the formation of florencite, whereas the positive correlation between the concentration of light Lns and K may reflect the difference between the solubility of double salts of K and Ln sulfates of light Lns and heavy Lns, respectively.

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Abstract  

Determination of major elements in natural solid samples by X-ray fluorescence spectroscopy (XRF) with a fusion disc technique is described. Data obtained by the present XRF analytical system were found to have satisfactorily high reliability. Five rock samples and a volcanic ash sample with varying ages ranging from the present to 180 000 years, derived by the current and past volcanic activities in the Unzen area, Nagasaki, Japan were analyzed for their major elements' compositions using the above mentioned system. The chemical composition of the magma under this area has changed very little at least over the last 180 000 years.

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Abstract  

Hot spring water and crater lake water samples were analyzed for their rare earth elements: (REE's) by neutron activation method, which, in the irradiation, sample preparation, incorporated a coprecipitation process in which aluminium was used as a collector. Ten REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Tm, Yb and Lu, were consequently detected and determined at the ppb level with satisfactory precision. It was shown that the aluminium coprecipitation is effective in enhancing concentrations of the REE's and reducing the amounts of interfering nuclides before neutron irradiation.

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Abstract  

Determination of the rare earth elements (REE's) in acidic hot spring and crater lake waters by neutron activation analysis (NAA), in which activation was performed mostly by epithermal neutrons (epithermal NAA) was investigated. Nine REE's, La, Ce, Sm, Eu, Tb, Ho, Tm, Yb and Lu, out of fourteen naturally existing REE's were determined at ppb levels with satisfactory precision. The epithermal NAA was found to be more effective in the determination of Sm, Tb, Ho and Yb than normal NAA, in which activation was performed mainly by thermal neutrons. Combined use of the epithermal and normal NAA's enabled the determination of eleven REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb and Lu.

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Abstract  

Previously undetermined three rare earth elements (REE's), Pr, Nd and Er, in acidic hot spring and crater lake waters were determined at ppb levels by neutron actavation analysis with the standard addition technique. Errors on final detemined values were 7.1–56%. Combining the present results and the results previously obtained amounts to the determination of all 14 naturally occuring REE's in the waters.

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Abstract  

Hot spring water samples have been analyzed for their rare earth elements (REE's) determination by the nondestructive neutron activation method. Five REE's, La, Ce, Sm, Eu and Yb, have consequently been detected and determined with satisfactory precision. The method has been found to be simple and suited for the simultaneous analyses of several samples. To determine all the REE's, however, some pretreatment of the samples will be necessary.

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