The amount of radioactive metal specimens dissolved in corrosive solutions was determined. The metals used in this investigation were Al-Cu alloys and Cu-Zn alloys, all of which were finished in plane sheets (1×20×50mm). Three kinds of solutions (0.1% NaOH, 0.1% HCl, and 3% NaCl) were used as corrosive media. The specific activity of each sheet was determined on 0.3-1.0mc after being activated in reactor. The method and apparatus used in the experiments are shown in Fig. 1 and the results obtained were as follows: (1) The minimum detectable limit of the amount of dissolved specimens was nearly 10-6g/dm2 and the dissolved amount was possible to be determined immediately after the specimens were immersed in the corrosive media. (2) By the analysis of the results, it was possible to determine some conditions of corrosion, which have never been observed in the previous studies. The typical results of experiments are shown in Figs. 2, 4, and 5.
The anodic oxide coatings of aluminium, which had been formed in sulphuric acid, was coloured by means of mono-azo dyes prepared by coupling of R-acid with several derivatives of aniline. Examinations were performed on the colours produced and their fastness to light and rate of absorption. The following results were obtained: (1) The absorption of the dyes by anodized aluminium in acidic dye bath was superior to that in alkaline dye bath. (2) The synthetic dyes, containing mono-radicals of Cl, SO3Na, NO2, COOH, and CH3 gave orange colour on the coatings. While, p-derivatives gave reddish and o- and m- derivatives gave yellowish colour. In other synthetic dyes containing OH mono-radicals, the colours given by means of o-, m-, and p- derivatives.