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정근우,박경진 한국산업융합학회 2024 한국산업융합학회 논문집 Vol.27 No.2
The purpose of radiological Dispersal Device(RDD) is to kill people by explosives and to cause radiation exposure by dispersing radioactive materials. And It is a form of explosive that combines radioactive materials such as Co-60 and Ir-192 with improvised explosives. In this study, we tested and evaluated whether it was possible to read the internal structure of an explosive using X-rays in a radioactive explosive situation. The improvised explosive device was manufactured using 2 lb of model TNT explosives, one practice detonator, one 9V battery, and a timer switch in a leather briefcase measuring 41×35×10 cm3. The radioactive material used was the Co-60 source used in the low-level gamma ray irradiation device operated at the Advanced Radiation Research Institute of the Korea Atomic Energy Research Institute. The radiation dose used was gamma ray energy of 1.17 MeV and 1.33 MeV from a Co-60 source of 2208 Ci. The dose rates are divided into 0.5, 1, 2, and 4 Gy/h, and the exposure time was divided into 1, 3, 5, and 10 minutes. Co-60 source was mixed with the manufactured explosive and X-ray image reading was performed. As a result of the experiment, the X-ray image appeared black in all conditions divided by dose rate and time, and it was impossible to confirm the internal structure of the explosive. This is because γ-rays emitted from radioactive explosives have higher energy and stronger penetrating power than X-rays, so it is believed that imaging using X-rays is limited By blackening the film. The results of this study are expected to be used as basic data for research and development of X-ray imaging that can read the internal structure of explosives in radioactive explosive situations.
정근우,강석춘,김영운,윤유정,김성현,박찬조 한국공업화학회 1999 응용화학 Vol.3 No.2
The metal-working industry is increasingly interested in synthetic metel-working fluids and coolants. Also an environmental aspect of the treatment of used fluid is important. The excellent lubricating properties of PEG based ester have been recognized in the area such as hydraulic fluids and compressor lubricants. The main purpose of this study was to investigate the drilling properties of PEG based ester synthesized from PEG and several diacid against aluminums using drilling machine. From the study, it was shown that there were some differences in the drilling properties depend on the structure and concentration of PEG ester.