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  • Author or Editor: F. Abdel-Rahim x
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Abstract  

This work is an investigation of the radiation stability of thoron-uranium complex. It deals mainly with the effect of absorbed dose on the absorption spectra of the complex at different complex concentrations. The radiolysis of the complex, was also investigated in presence of varying concentrations of ethanol and methanol. The decrease in absorbance at the characteristic peak as a function of absorbed dose, complex concentration, and alcohol concentration was used to calculate the G-value and the specific rate of bimolecular interaction of the complex molecule with water radiolysis products. The radiolysis mechanism was discussed in the light of the results.

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Abstract  

The study includes the effect of absorbed dose on the absorption spectra of thoron solutions at different pHs and different concentrations. The effect of absorbed dose on the linear response limit and the decolouration yield (G-value) were determined. These results were used in determining the dosimetric characteristics of the dye solutions.Some of the investigations were undertaken in presence of varying concentrations of ethyl alcohol. The results helped in recommending a decolouration mechanism, and in calculating the specific bimolecular rate constant for reaction of the dye with OH radicals.

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Abstract  

The effect of -radiation on the electronic absorption spectra of the negatively solvatochromic dyestuff1, namely, 4-(4-N,N,-dimethylaminostyryl)-pyridinium methiodide in water and dimethylsulphoxide solvents is investigated. Ionizing radiation at different absorbed doses brought about gradual bleaching of aerated dye solutions. The -radiation-induced degradation and the consequent changes in the electronic absorption spectrum of dye 1 are discussed in the light of the theoretically calculated spectrum. The linear response range of dye1 in case of DMSO solution is wider than that in H2O. The results demonstrate that the radiochromic dye solution offer dosimetry in the low dose range by means of visible spectrophotometric analysis.

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Abstract  

The effect of absorbed dose on the decolouration of U(VI)-arsenazo-1 complex solutions has been investigated at pH 8.3. G-values were determined as a function of complex concentration as well as of OH, e aq scavengers. Using competition kinetics, rate constants were determined and the degradation mechanism discussed.

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