[en] The characteristics of the Goiania accident (a restricted and local contamination) together with the fact that the region has received no contribution from the Chernobyl accident, neither from the atomic tests represents an unique opportunity to study the behaviour of ¹⁴⁷ Cs at an urban area. The study of the resuspension and deposition processes of the ¹³⁷ Cs associated to surface soil was performed at a house at the 57th. street near the main primary focus. It was decided to use the two gardens of the house, where continuous measurements of aerosol and total deposition took place. Impactor measurements were also performed to evaluate the size distribution of particles in the air. The results as a whole suggests a very complex pattern for the ¹³⁷ Cs resuspension and deposition in Goiania, indicating to be these mechanisms local,phenomena and without evidences of a significant spreading of ¹³⁷ Cs from the places of primary contamination. (author). 63 refs., 14 figs., 9 tabs

[en] A spectrophotometric determination of thorium with arsenazo III (1,8 dihidroxynaphtaline - 3,6 sulfanic acid - 2,7 bis (azo-2) - phenil argonic acid) was carried out aiming to analyse this element in water. In order to eliminate possible interferences, a coprecipitation with lantanium fluoride was used followed by an extration with 0,2 M TTA (tenoil-trifluor - aceton) / Benzen. The results showed a good agreement with the ones obtained by alfa-spectrometry. (Author)

[en] A spectrophotometric method for the determination of thorium with arsenazo III (1,8 dihidrozynaphtalene 3,6 sulfanic acid 2,7 bis (azo-2) phenyl arsonic acid) was developed for the analysis of this element in environmental samples. In order to eliminate possible interferences, a coprecipitation with lantanium fluoride was used followed by an extration with 0,2M TTA (tenoyltrifluoroacetone)/benzene. The results are in agreement with those obtained by alfa-spectrometry. (Author)

[en] A spectrophometric determination of thorium with Arsenazo III (1,8 dihidroxynaphtlaline - 3,6 sulfanic acid - 2,7 bis (azo-2) - phenil arzonic acid) was carried out aiming to analyse this elemet in environmental samples. In order to eliminate possible interferences, a coprecipitation with lantanium fluoride was used followed by an extraction with 0,2 M TTA (tenoil - trifluor-aceton)/Benzen. The results showed good agreement with the ones obtained by alfa-spectrometry. (Author)