[en] CaSO₄ activated with thulium for radiation dosimetry purposes was produced at the Pasar Jumat Research Center. The phosphor is very sensitive and is also characterized by a simple glow curve and low fading, making the phosphor suitable for dose measurements over extended period of time. The factors influencing the glow curve, the sensitivity, the fading, the linearity, the producibility, and the stability of the material, are discussed. The minimum detectacble dose was around 73 micro rontgen and the fading was 1% per month. (author)

No abstract available

[en] The most important insects found on coffee and tobacco in storage are A. fasciculatus and L. serricorne, respectively. Some genera of mold, such as Rhyzopus, Aspergillus, Penicillium and Mucor, were found on stored coffee. A preliminary study of radiation disinfestation of coffee beans was carried out using 24 bags (each l.5 kg) of Arabica coffee. Each bag was infested with l00 adults of l-day-old to 8-day old A. fasciculatus. One month after infestation, the bags were divided into 6 groups (4 bags each). Five groups were irradiated with doses of 0, 0.05, 0.l0, 0.20, and 0.40 kGy, while the sixth group was fumigated with about 3 g phosphine-m/sup 3/. The work is still in progress. The preliminary data (insect density, percentage weight loss of coffee beans, and mold infestation) from l0 observation periods during 20 weeks of storage after treatment was reported. Radiation disinfestation of tobacco was done on 36 export-size bales (each l00 x 75 x 40 cm in size and about k00 kg in weight) of tobacco. Each bale was infested with larvae, pupae, and adults of L. serricorne. One week after infestation, the bales were divided into 3 groups, the first group kept untreated as controls, the second group irradiated at a dose range of 0.30 to 0.60 kGy, and the third group fumigated with about 3 g phosphine/m/sup 3/. Insect density, leaf moisture content and mold infestation will be observed after 0, 2, 4, and 6 months of storage. The work was begun in October l983 and data presently are being collected