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  • Author or Editor: J. Lesný x
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Abstract  

Preliminary studies were conducted on the coupling of sub-super equivalence isotope dilution analysis and radiometric flowinjection analysis techniques.109Cd was used as tracer and an attempt was made for extraction of cadmium from the aqueous phase into the organic phase (chloroform) by using dithizone.

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Abstract  

The influence of -radiation on the structure of Langmuir-Blodgett (LB) layers of poly (3-hexadecylthiophene) in mixtures containing stearic and linolenic acids has been studied. The action of -photons leads to structural changes in the conducting polymer backbone as well as to disrupting oriented LB film structures.

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Abstract  

The influence of radioactive krypton85Kr on the surface properties of poly(3-pentylthiophene) has been studied. Irradiation by gaseous85Kr leads to structural polymeric chain changes, which induce after iodine doping the formation of charge-transfer complexes with iodine as well as with gaseous sulfur dioxide manifesting itself by the increased electric conductivity. The presence of ammonia brings about reaction with iodine bound in the complex with a conducting polymer.

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Abstract  

The growth and morphology of filamentous fungusTrichoderma viride grown in the presence of various Co concentrations were studied. Using60Co, the cobalt content in mycelium and conidia was determined. No influence of60Co-radiation on growth and morphology was observed.

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Abstract  

The uptake and distribution of cobalt by filamentous fungus Trichoderma viride has been studied. By means of60Co the cobalt concentrations in conidia and mycelium were determined.

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Abstract  

Trace amounts of cadmium were determined by sub- and super-equivalence isotope dilution analysis in model solutions and water samples. Cd/II/ was labelled with109Cd and was extracted in CHCl3 as dithiozonate. AAS was chosen as reference analysis.

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Abstract  

The influence of -radiation on iodinedoped poly (3-pentylthiophene) has been studied. Doping accompanied by -radiation brings about a decrease of iodine release rate. An increased dopant concentration in the poly (3-pentylthiophene) leads to an increased conductivity, which may be accounted for by the formation of bipolarons in the irradiated and doped samples.

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Abstract  

The subject of this paper was to determine some radionuclides in fly-ashes of Czechoslovak origin.226Ra,228Ac and40K were chosen because of their high information value. The radiometric measurements were carried out by means of a semiconductor detector.

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Abstract  

In order to gain biosorbent that would have the ability to bind cesium ions from water solution effectively, potassium nickel hexacyanoferrate(II) (KNiFC) was incorporated into the mushroom biomass of Agaricus bisporus. Cesium sorption by KNIFC-modified A. bisporus biosorbent was observed in batch system, using radiotracer technique using 137Cs radioisotope. Kinetic study showed that the cesium sorption was quite rapid and sorption equilibrium was attained within 1 h. Sorption kinetics of cesium was well described by pseudo-second order kinetics. Sorption equilibrium was the best described by Freundlich isotherm and the distribution coefficient was at interval 7,662–159 cmg−1. Cesium sorption depended on initial pH of solution. Cesium sorption was very low at pH0 1.0–3.0. At initial pH 11.0, maximum sorption of cesium was found. Negative effect of monovalent (K+, Na+, NH4 +) and divalent (Ca2+, Mg2+) cations on cesium sorption was observed. Desorption experiments showed that 0.1 M potassium chloride is the most suitable desorption agent but the complete desorption of cesium ions from KNiFC-modifed biosorbent was not achieved.

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Abstract  

The subject of this paper was to determine some radionuclides (226Ra,228Ac and40K) in construction materials of Slovak origin and to evaluate the risk of their practical use.

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