Authors:L. Nagy, G. Török, G. Fóti, T. Tóth, and L. Feuer
For the selective removal of the matrix activity (24Na,32P and42K) in the neutron activation analysis of biomedical samples the inorganic separators “hydrated antimony pentoxide”, zirconium
phosphate, and titanium phosphate were prepared. The sorption parameters of the samples were determined via elution chromatography
techniques, with appropriate tracers. The basic principles of the sorption processes were investigated, and the experimental
conditions were optimized. These inorganic separators were then applied, combined with a distillation procedure and an ion-exchange
separation, for the determination of the following trace elements in animal blood samples: Mn, Co, Cu, Fe and Zn.
Authors:K. Szabó, L. Nagy, G. Török, D. Hegedüs, and G. Fóti
A control system for monitoring the radioactive concentration in aqueous wastes of nuclear installations was elaborated. The
mobile station developed for in situ control enables simultaneous measurement of gamma radiation in the energy range of 0.15–2.0
MeV and that of beta radiation in the energy range of 0.3–2.0 MeV by means of a combined scintillation detector. Disturbing
effects of accompanying and secundary radiations on the determination of the counting efficiency vs. radiation energy functions
used in calculation of the radioactive concentration limits as well as some experiences during a long time of operation of
the system have been discussed.
Authors:S. Cavallaro, A. Colligiani, G. Cum, and S. Foti
The previously found strong dependence of the polymerization enthalpy on the reaction temperature has been rationalized. The
temperature dependence is to be ascribed to the existence of a ‘ceiling temperature’ for the polymerization process of the
pyrrole monomer. The determined ceiling temperature has beenT≊350 K when FeCl3 was used as the oxidizing agent in CH3CN solution. The existence of a ceiling temperature together with its already determined exoenthalpic nature allows to classify
the polymerization reaction as an exoentropic one.
From the dependence of the yield of insoluble polymer on the reaction temperature, the trend of the relative mean numeral
molecular massMn for the different obtained polymers has been determined. Measurements of electrical conductivity on pressed pellets of the
different polymers allowed to establish a correlation between theMn value and the conductivities The dependence of the conductivity on the exposition time to the air allowed to do some essays
on the aging behaviour of the obtained polypyrrole. By making some assumptions, an absolute calorimetric determination of
the value ofMn of polypyrrole was tempted together with that of the related poly-N-vinilpyrrole.