[en] Natural and artificial radionuclides in the environment of the Gulf of Thailand were studied during 1989-1991. In the study, surface water, sediment at 5 locations between latitudes 9 degree 28 minute N and 13 degree 15 minute N longitudes 100 degree 35 minute E. and 5 species of marine biota were collected in 1989. In 1990 and 1991, 9 and 7 species of marine biota were collected from the Gulf of Thailand and the Andaman Sea respectively. These samples were prepared and analyzed for gamma-emitting radionuclides as well as some beta and alpha-emitting radionuclides such as C-14, Sr-90, Pu-239,240, Po-210 etc. The results indicate the present status of radioactivity level of the environment of the gulf and the sea

[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 sterilization dose setting by ISO 11137 method 1 was conducted for natural rubber examination gloves provided by a local factory. The suitable sterilization dose for an average product bioburden falls between 20 - 25 kilogray. Maximum dose of 25 or 50 kilogray results in no changes of tensile s and elongation at break. Samples of examination glove were irradiated using various doses between 10 - 50 kilogray. Analysis of soluble protein content using modified Lowry method was carried out and the results revealed that irradiation did not affect the decrement of soluble protein content in this case. However, thin film samples were prepared in laboratory and treated in the same procedure. The results were also the same. The results did not show any correlation. Two factors are possibly presumed : un consistency of samples and the irradiation of finished products could not affect those soluble proteins in rubber gloves

[en] The strippable paint, one of the adhesion method, is to decontaminate solid surface of materials or/and a large area. Two kinds of specimen planchet, SUS 304 stainless steel and polycarbonate plastic, contaminated with radioactive ¹³⁷Cs were studied under various conditions. It included surface bottom types, the flat and convex concentric circle type, normal condition at room temperature and overheat condition (∼80 degree celsius). This method used coating paints which contains some elements to have a reaction with radioactive materials selectively. ALARA-Decon clear, Rempack-X200 clear, JD-P5-Mrs.Coat and Pro-Blue-color guard were selected to use as the coating paints. The contaminated surface was coated by the strippable paint under the optimum time, followed by peeling the paint seal. The Rempack-X200 showed the best result, the highest decontamination efficiency which are about 99-100% for all conditions of specimens. The JD-P5 and ALARA-Decon showed good results, which are 98-99% decontamination efficiency for the normal condition set of specimens and about 94-97% for the overheat set of specimens. They can decontaminate polycarbonate specimens better than stainless steel specimens. The Pro-Blue-color guard showed the lowest decontamination efficiency of which 60% for polycarbonate specimens at normal condition and 40%, 30% for stainless steel specimens at normal and overheat conditions respectively. There was no effects of surface bottom types significantly

[en] PSA ELISA kit was developed and compared to a commercial PSA ELISA kit (Cobas Registered trade mark Core PSA EIA, Roche Switzerland) with a correlation of 98.9% (r 0.989, p < 0.05). The precision of the assay kit evaluated by intermal quality control studies shown that the coefficient of variation of high, medium and low control were 4.4, 3.6 and 4.7% respectively. The sentuvity of detection was 0.25 ng/ml. This PSA ELISA kit has been used for detection of PSA in serum of 571 patients ages between 25-93 years old with satisfactory results. The normal range of PSA is 0 - 3.46 ng/ml (X-bar = 2SD, n = 384). The mean value of PSA in Prostate carcinoma before treatment and after successful treatment are 77.30 ng/ml (n = 53) and 1.64 ng/ml (n = 25) and increase to 53.71 ng/ml (n = 8) in metastasis. In Benign Prostate Hyperplasia (BPH) the range of PSA is 0 - 27.52 ng/ml (n = 74). Phi (φ) coefficient analysis shown that the correlation of PSA and Prostate carcinoma is 63.8% with a sensitivity and specificity of 100% and 86.9% respectively

[en] The effects of temperature, time and reagent-to-mineral ratio on the completeness of digestion of xenotime with 40 per cent sodium hydroxide were studied. The digestion at 180 degrees C with an alkaline-to-mineral ratio of 2 : 1 for a period of 3 hours gave a digestion yield of 90 per cent. The mixture of rare earth hydroxide was dissolved by concentrated hydrochloric acid and separated into groups by gradient pH precipitation. Yttrium was found to precipitate between pH 3.5 - 7.0. The compositions of the rare earth hydroxide were determined either by X-ray fluorescence or instrumental neutron activation

[en] The study of utilization of Universal Reactor Simulator in Nuclear Technology are divided into two parts. The first part deal with the description of the background of linear operation of analog computer. It describes the principle of linear computing circuits, time and amplitude scaling. The second part gives the experiment for nuclear science problems which can be solved by analog computer e.g. Xenon poisoning, Samarium poisoning, radioactive decays, activation, gamma attenuation and reactor kinetic equations

[en] Four ancient Thai fighting swords from the Bangkok National Museum and iron ore from Kao Tab Kwai, Lopburi were studied by neutron activation analysis, metallography and chemical analysis. The results of these scientific studies show that all of these four swords are made of plain carbon steel, containing trace elements which have no effect on the physical and mechanical properties of the steel. The trace elements which were found in the iron ore are quite similar to those found in one of these swords. This means that the iron in one of the swords may have come from ore found at Kao Tab Kwai, Lopburi