In order to reveal the reactivity of aliphatic dicarboxylic acids, the hydrogen-isotope exchange reaction (T-for-H exchange reaction) between poly (vinyl alcohol) labeled with tritium at hydroxy group and one of aliphatic dicarboxylic acids in 1, 4-dioxane has been observed in a liquid-solid system in the range from 30 to 90°C. It was consequently found that (1) the greater the number of methylene groups in a aliphatic dicarboxylic acid is, the smaller is the reactivity of the acid; (2) a large difference is found between the reactivity of acids having even numbers of methylene groups and those having odd numbers, and the reactivity of the former is generally larger than that of the latter; (3) relating to the decrease of the reactivity of the acids with increasing number of methylene groups, the rate of the decrease in the case of even numbers is smaller than in the case of odd ones; (4) the reactivity of aliphatic dicarboxylic acids in T-for-H exchange reaction is largely dependent on the configuration (e.g., cisoid or transoid) of the two COOH groups.
Using electron spin resonance (ESR) spectroscopy, we revealed four radical species in the irradiated pepper. The representative ESR spectrum of the pepper is composed of a sextet centered at g=2.0, a singlet at the same g-value, a singlet at g=4.0 and side peaks near g=2.0. The first one is attributable to a signal with hyperfine (hf) interactions of Mn2+ion (hf constant= 7.4 mT) . The second one is due to an organic free radical that may be induced by the (γ-ray irradiation. The third one may be originated from Fe3+ion in the non-hem proteins. Those three signals were found in the pepper sample before irradiation. The fourth signals were found at the symmetric position of the organic free radical, i.e, the second signal. The progressive saturation method of the ESR microwave power indicated quite different relaxation behaviors of those radicals. The method reflects four independent radical species in the irradiated pepper. Relaxation time for the singlet signal centered at g=2.0 revealed that the signal is due to the typical organic free radical.
The current study was performed to investigate the influence of high temperature on the value of radiation dose measured by optically stimulated liminescence (OSL) dosimeter or radio photo luminescence (RPL) dosimeter (glass dosimeter) . Serial measurements of temperature in the car confirmed that it can rise to 80°C or higher in the area irradiated with sun beam. The relationship between the temperature and the radio dose measured by X-ray irradiated OSL dosimeter or glass dosimeter under the condition from 50°C to 90°C after the set of 3h. to 72h. The value measured by OSL dosimeter tended to be lower with higher temperature or longer setting time. On the other hand, those factors did not influence the value measured by glass dosimeter.
Tritium concentrations in river water have been measured at Toki area (Toki-shi, Gifu-ken, Japan) since 1982. The tritium concentrations decreased exponentially, and their apparent half-lives were distributed between 2.3 and 7.2 year. It is suggested that the time during which rainwater changes to groundwater and is discharged again as river water is different at spot by spot. As a result of comparison with yearly variations of flow rate, a inverse correlation was recognized between tritium concentration and flow rate in some spots.