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Abstract  

Two improved processes of99Mo production have been developed on laboratory scale. The first one allows to purify Mo of natural isotopic composition from tungsten impurities from 64 to <10 ppm by using preferential adsorption of tungsten on hydrated tin(IV) oxide (SnO2 nH2O) before irradiation in a nuclear reactor. The second process deals with the separation of pure fission product99Mo from235U irradiated in a reactor. Two versions of separation process for production of fission99Mo have been developed. Both versions start with the dissolution of235U oxide target in nitric acid and are based on sequential use of alumina and anion exchange resin AG® 1-X8 columns. The yield of99Mo in both versions is 80–89%.

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Abstract  

Tin has been determined in biological materials by NAA of the γ-emitting 40-min123Sn and 9,7-min125Sn isotopes at the sub-ppm level. For123Sn, samples are wet-ashed after irradiation, whereas to allow fast radiochemistry for125Sn, the samples are dry-ashed prior to the irradiation. Both separation techniques rely on selective solvent extraction of tin(IV) iodide, and NaI(TI) counting. Comparative analyses of several materials by both methods gave good agreement, indicating that tin is not lost on dry-ashing and that simple dissolution of the ash in an HCl−HI mixture is complete. Results by both techniques are presented for the standard materials Bowen's Kale and NBS Orchard Leaves, and for some other materials.

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Abstract  

Tin(IV) antimonate (SnSb), cerium(IV) antimonate (CeSb), silicon(IV) antimonate(SiSb) ant titanium(IV) antimonate (TiSb) were prepared under various conditions. The ion-exchange properties and the thermal stability of these materials were examined in order to elucidate their applicability to the processing of radioactive liquid wastes. Capacity, equilibrium measurements, adsorption isotherms and the selectivity patterns for Cs+, Sr2+, Co2+ and Eu3+ ions on these sorbents at different conditions were determined. The effect of high concentrations of salts and complexing agent as interfering ions in the feed solutions on the distribution coefficient of the metals, mentioned above, was tested as a function of [HNO3]. Based on the results obtained, practical separation experiments on column were performed.

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Abstract  

A short review of the thermal analysis data available for dithiocarbamate complexes of tin(II) and tin(IV) is presented. Since the relevant thermal decomposition mechanisms are complicated, even for decompositions in inert atmospheres, mechanisms postulated on the basis of thermal analysis data alone are suspect. Realistic thermal decomposition mechanisms for these complexes can only be formulated when the relevant decomposition products are unambiguously identified. In this short review, an attempt is made to identify trends in these thermal analysis data, with particular reference to structural features of the corresponding complexes.

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of the prepared materials, based on modern methods (such as SIMS, XPS and ion beam techniques). The advanced materials synthesized and characterized include (among others) cerium activated strontium sulphide, yttrium stabilized zirconia, tin(IV) oxide

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. Anirudhan , T. S. 2001 Immobilization of heavy metals from aqueous solutions using polyacrylamide grafted hydrous tin(IV) oxide gel having carboxylate functional groups Water Research

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/s, which is characteristic of tin(IV). The broadening of the singlet can be mainly attributed to the amorphous character of the sample. In case of second sample, the pattern recorded at 298 K (Fig. 2 b), contains three peaks which can be decomposed to one

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[ 4 ]. Moreover the copper oxide has a remarkable mineralizing effect on different type of clinkers, i.e., with high C 2 S or C 3 S content [ 4 ] or Portland clinkers with 3CaO·3Al 2 O 3 ·CaSO 4 content [ 5 ]. Tin (IV) oxide was also reported to be a

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Introduction Inorganic ion exchangers have been of great interest for the last six decades, zirconium(IV) phosphate being the most extensively studied material [ 1 , 2 ]. Next to this are the tin(IV)-based materials, due to

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proposed, namely: NaSn(HEDTA)(H 2 O) for tin (II) and NaSn(OH)(EDTA)(H 2 O) 2 for tin(IV), respectively. It means that theoretically two oxidation sates exist on the basis of the tin environment, but during the investigations we practically detected only

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