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  • Author or Editor: M. Földesová x
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Abstract  

The influence of -irradiation on the paramagnetic properties of non-doped polyacetylene at low and high radiation doses has been studied and summarized. The dependence of the EPR spectra on the radiation dose in irradiated polyacetylene has been measured. No essential changes of the spin mobility as a consequence of irradiation were observed. Our measurements of spin concentration confirm the high resistivity of non-doped polyacetylene to radiation.

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Abstract  

The ion-exchange ability of NaOH-treated clinoptilolites with regard to Cs+ and Co2+ have been studied by a radiochemical method, enabling to calculate the sorption coefficient. The surface characteristics, total cation exchange capacity and X-ray structural analysis were measured as well. The measurements were done on Slovak clinoptilolite. Comment are made on a possible explanation of increasing sorption coefficient.

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Abstract  

137Cs and60Co were sorbed from model solutions and waste water on chemically treated granular zeolite. The zeolite was incorporated into cement slurries based on blast furnace slag (BFS). The compressive and bending strength were measured after different times of hydration. The leaching tests were performed in water, base and acid solutions. The leachability was more pronounced only for samples in acidic solutions.

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Abstract  

Zeolites chemically modified with 1, 4 or 6 M aqueous solutions of NaOH were studied by DTA, TG and ETA (emanation thermal analysis) in the temperature range 201–200°C. The structural changes in the modified zeolites at room temperature and in the modified zeolites annealed at 1000°C were studied by XRD analysis. Thermal analysis demonstrated dehydration, dehydroxylation, structural changes and a glass transition. A gradual loss in crystallinity of the chemically modified zeolites was also observed. XRD analysis revealed structural changes caused by chemical treatment and also by annealing.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Földesová, P. Lukáč, P. Dillinger, E. Klosová, Z. Málek, E. Večerníková, and V. Balek

Abstract  

Zeolites from Nižný Hrabovec (Slovak Republic) were, modified with solutions of NaOH. The changes of zeolites in the temperature range 20–1200 °C were studied by thermal analysis (DTA, TG, ETA), X-ray analysis and REM analysis. Thermal analysis showed that the process of dehydration started between temperatures 20 and 600 °C, over this temperature the dealumination and structural changes have taken place. X-ray analysis and REM analysis showed the structural changes of natural zeolites and gradual loss of cristallinity of the chemically modified zeolites.

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