This paper described experiments on the adsorption of radon gas on surfaces of various materials. The experiments were carried out on three kinds of materials : Poly (vinyl chloride), polyethylene and stainless steel. On stainless steel, adsorption was not detectable. On the other hand, there was clearly adsorption on poly (vinyl chloride) and polyethylene. A poly (vinyl chloride) sheet of one square meter surface in a 5.3 L container absorbed approximately 20% of the radon. Radon adsorption has to be taken into account when radon concentration measurements in the air.
In order to the practical use of radicidation of beet red, natural food colorant with low heat stability and high possibility of microbe contamination, we studied on the energy dependency and dose rate effect for the influence on functional properties of the beet red colorant. For the elucidation of energy dependency, the γ-ray (1.33 MeV) and electron beams with different accelerating voltages (0.75, 1, 2.5, 5 and 10 MeV) were used. The dose rate effect was studied under the different dose rate by using γ-ray (0.723, 1.91 and 4.55 kGy/h) and electron beams with accelerating voltage of 10 MeV (1.0×103, 2.6×103, 7.0×103, 2.0×104 and 5.0×104kGy/h) . The results obtained in this study showed that regardness of these energy and dose rate, the functional properties o f the beet red colorant were little affected by irradiation less than 25 kGy of ionizing radiations.