[en] The 6th conference on nuclear science and technology was held on 2 - 4 December, 1996 in Bangkok. This conference contain papers on non-power applications of nuclear technology in medicine, agriculture and industry. These application include irradiation of food for des infestation; tram technologies used in diagnosis and therapy and radiation chemistry important to industrial processes. Some technologies which evolved from the development of nuclear power industry are also discussed

[en] Neutron produced in research reactor can be used for neutron capture therapy on malignant of brain tumor and skin cancer. The principle is that boron compounds are injected selectively into cancer cells which are irradiated by thermal neutron. The cancer cell is destroyed by alpha particle and lithium particle, both of which are produced by nuclear reaction ¹⁰ B(n,α)⁷ Li. In Japan, the research and test was started about 30 years ago, and necessary surgical and irradiation technologies were actively proceeded along with the development of the appropriate boric compounds which could be highly absorbed into the tumor cell. After the selectively absorbable compound Na₂ B₁₂ H₁₁SH was found, the potential of this therapy has been remarkably increased. Now in Japan, the clinical results of BNCT have been promoted to be a survival rate of more than 50 percents for the therapy of hundreds cases. Here, the progress and the results in Japan on BNCT for cancer mainly focusing to brain tumor together with the practice of the therapy, the applicable boric compounds, the neutron irradiation facilities, the methods of dosimetry including prompt gamma analysis, the improvement of BNCT by using epithermal neutron and other technologies are to be introduced

[en] Two different types of SSNTDS CN-85B and L R-115 Type II B were used to record alpha tracks which were generated from eighteen curies of ²³⁸ Pu-⁹ Be neutron source that immersed in water phantom tank with a cylindrical shape. The source is located at Physics department, Faculty of Science, Prince of Songkla University. The films were placed radially in water phantom starting from the origin up to the distance 50 cm. with 5 cm. interval. After one week, the films were collected and etched with 2.5 N NaOH at 60 degrees C about 25 and 90 minutes etc. in order to enlarge the latent alpha registration tracks. The track density per unit area of each film was determined by optical microscope at 400 x magnifications. We found that L R-115 Type II B film is more sensitive to record alpha track than CN-85B film and we have used L R-115 Type II B film for further studies. The results showed that the profile of alpha track densities in the radial direction are in good agreement with neutron dose rate calculations using program ANISN under point source condition. This implies that a low cost films L R-115 Type II B can be used as a neutron dosimeter

[en] The impact of gamma irradiation with doses between 0 and 8 kGy on microbiological quality of chicken meat produced in Japan and micro flora change of irradiated chicken meat were studied. Radiation at the dose 2 kGy resulted in 4 log cycles reduction of total aerobic bacteria, 5 - 6 log cycles reduction of lactic acid bacteria and 2 log cycles reduction of fungi and yeasts. For the coliforms, it could be eliminated below detectable level by irradiation dose of 1 kGy. For the chicken flora-analysis, it was found that chicken of each area had their own specific microbial community structure. Flavobacterium and Pseudomonas were found to be dominant organisms in the microflora of Japanese chicken meat. Irradiation with dose 2 kGy resulted in disappearance of Lactobacillus and Pseudomonas. The microorganisms which dominated in irradiated chickens with doses of 2 kGy and higher were Psychrobacter and yeast. These studies support the view that radiation improves the microbiological quality of chicken meat and substantiate that radiation does not present hazard resulting from a change in the microflora of irradiated chicken

[en] The survey of the mango seed weevil during February to July of 1993-1995 at Ratchaburi province, Chachoengsao province and Chieng Mai province. Only at Chieng Mai province was found at 2.35 percent to 37.36 percent. Outbreak occurred in the mango orchard which there was no insecticide application and pruning. Over 20 years old of the mango trees with the crevices of the bark around the trunk would be the host area of the adult mango seed weevil. The adult would hibernate by living in the crevice of the bark and in the ground around the base of the trunk. All specimens of mango seed weevils found was Sternochaetus oliveri (Faust). The study on effect of gamma radiation on the adult of mango seed weevil found that L D₉₉ is 1.39 kGy after 28 days of irradiation. They were very slow movement without feeding and mating

[en] The effect of gamma radiation on microorganisms in sludge from Huay Kwang Sewage Treatment Plant and Vajira Hospital showed that total bacterial counts were reduced to 2-3 log cycles and 1-2 log cycles at 5 kGy irradiation with and without aeration, respectively. Inactivation of coliform bacteria in sludge required irradiation with and without aeration at the dosages of 3-4.5 and 4-5 kGy, respectively. A dose of 2-3 kGy was sufficient to inactivate fecal coliform bacteria and E. coli. The doses used for inactivation these bacteria depend on the irradiation condition and solid content in sludge sample. Irradiation with aeration led to an increased microbial inactivation. According to our results, the frequency of occurrence of salmonella e contaminated in sludge from Huay Kwang Sewage Treatment Plant and Vajira Hospital was 50% and 75%, respectively. A dose of 2 kGy irradiation with or without aeration, salmonella e could not be detected in any sludge. Clostridium perfringens organisms were also detected in non-irradiated and irradiated sludge from both sources. Moreover, a dose of 5 kGy irradiation with or without aeration was not enough to eliminate C. perfringens. However, no shigella e were isolated from any treatment of sludge

[en] Radiopharmaceutical kit is a diagnostic compound which contains Stannous (II) as a reducing agent. The quantity of Stannous (II) is depended on the type of kits. So the quantity of Stannous (II) is determined by polarographic method with Differential Pulse Voltammetry (D P Mode) in which a saturated calomel electrode is used as anode and a dropping mercury electrode is used as cathode. Both of electrodes are immerged in the premixed solution of supporting electrolyte and analytical Stannous (II). The Stannous (II) is determined by direct method Stannous (II) is analyzed in the form of Stannous; Sn²⁺ itself, and indirect method Stannous (II) is analyzed in the form of S tannic; Sn⁴⁺ (Sn²⁺, + N H 4⁺----> Sn⁴⁺). Both methods are done at polarographic half wave potential -470 and -520 mV respectively. The Limit of Detection (LOD) of the direct method is 1.9445 micro g and indirect method is 1.3018 micro g. The result received from indirect method is much more accurate than the direct method (Sn²⁺). The accuracy of the direct method is about 97.5-102.5% recovery

[en] The study of rare earths separation by solvent extraction, which is a part of monazite breakdown process, has been done by shaking in separatory funnel to initiate the cross-current and the counter-current with reflux technique. Rare earths in the aqueous nitrate solution were extracted by 50% tributyl phosphate (TB P) in kerosene. The results show the preferable separation of the latter to the former technique

[en] Quality of fruit fly, bactrocera dorsalis (Hendel) in mass production is important for controlling pest populations by means of the sterile insect technique. The experiment was to study the quality of fruit fly after sifting pupae by mechanical sifter. Laboratory-reared pupae, held at 26 ± 1 degree C were sifted at intensity of 18 rpm in a rotary sifting device at 1, 2, 3, 4, 5, 6, 7 and 8 days of age. The quality of fruit flies were determined on adult eclosion and flight capability. The results showed that there were no significantly different (P < 0.05) in adult eclosion between control with sifted pupae at 1 to 8 days of age. However, there were significantly different (P < 0.05) in flight capability between control and sifted pupae at 1, 5, 6, 7, 8 days of age with sifted pupae at 2, 3, 4 days of age

[en] An attempt was made to reduce irradiation dose for radiation vulcanization of natural rubber latex. A promising method was to partially crosslink the latex by radiation vulcanization using n-butyl acrylate (n-BA) as sensitizer and t-butyl hydroperoxide (BHPO) as a co-sensitizer followed by redox vulcanization using residual BHPO as an oxidant and either fructose or tetra ethylene penta mine as reducing agents. It was found that the irradiation dose was reduced to 4 kGy with 5 phr n-BA as sensitizer and 0.1 phr BHPO as co-sensitizer. Successive crosslinking to full vulcanization was done by redox vulcanization using either 4 phr fructose at 60 degree C for 3 hours of 0.4 phr tetra-ethylene penta mine at room temperature for 1 hour. The rubber films obtained had tensile strength of about 25 MPa, modulus 300% of 0.9 MPa and crosslink density of about 1.5 x 10¹⁹ crosslink/cm³. It was noted that the rubber film from the co-vulcanization was the average value of the values obtained by radiation vulcanization and redox vulcanization