RESUMO
The use of filters with appropriate thickness of different elements produces a method to quasi-monochromatize X-ray beams. In the present study the filters were produced in a boric acid matrix, using the elements Mo, Sb, Cs, Ce and Gd. The thickness of the filters varied from 50 to 300 microm for a high voltage tube operating from 30 to 70 kVp. The parameters analyzed were the beam resolution, measured by its FWHM as a function of filter thickness, and the reduction of beam intensity. The results show a comparison between conventional tomographies obtained with different filters and application in the technique of differential tomography, with double energy for identification of elements such as Zr, Nd, Ba and Sm.
RESUMO
The international commerce of vegetable products is often dependent on the quarantine protections that are imposed by the importing countries because of the fear of contamination by fruit flies. The use of ionizing radiation as a treatment for these products can be used to remove this problem and a real proof of irradiation can contribute to the implementation of the international commerce. ESR measurement on the pulp of vegetable products can be used as a proof of irradiation using the species introduced in cellulose that are found uniquely in irradiated products. The stability of these species are compatible with the life of the products analyzed. The pulp signal intensity is sufficient to identify products irradiated with doses as low as 100 Gy for some fruits.
