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        검색결과 10

        1.
        2023.05 구독 인증기관·개인회원 무료
        The types of waste generated in radiation controlled areas of nuclear facilities are very diverse. Among them, the waste containing hazardous materials such as electrical equipment and fire safety equipment that do not directly handle radioactive materials is also primarily classified as radioactive waste because it was used and stored in the radiation controlled area. Such wastes include periodic consumables such as fluorescent lamps, fire extinguishers, batteries, and gas containers after use. The waste is ambiguous and cannot be easily treated as radioactive waste or waste subject to clearance, and has been stored in a radiation controlled area for a long time, and the amount is continuously increasing. The storage space is saturated and has difficulty in management. IAEA ISO-7503-2016 clearly states that surface contamination measurement can be applied to surface contamination substrates (impermeable, non-activated) instead of volume contamination measurement. In order to solve these concerns, some facilities within the Korea Atomic Energy Research Institute were selected to explore self-disposal methods based on surface contamination in consideration of the characteristics of waste and facility contamination. The surface contamination degree and qualitative gamma spectroscopic analysis were carried out by the method. First, we examined the characteristics of the facility, the history of the air pollution level of the usage/storage space, and periodic inspection records. Second, we measured the physical properties (area/weight) of the waste in the same treatment way as the existing waste. Third, gamma dose rate and surface contamination (direct/indirect method) are measured for the entire area to confirm contamination is possible. It was confirmed that the concentration standard was satisfied. In order to clarify the presence of contamination, a qualitative method of gamma nuclide analysis was also performed. All surveys/measurements of 4 types of waste at 7 facilities were performed and it was confirmed that all waste satisfies the permissible concentration standard for clearance which conservatively set at 0.1 Bq/g as the permissible concentration standard. In the future, We hope that you will use this as a reference to search for easier disposal methods for regulatory bodies and specified waste disposal methods, and contribute to reducing the amount of radioactive waste generated.
        10.
        2010.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bone morphogenetic proteins (BMPs) are known to promote osteogenesis, and clinical trials are currently underway evaluating the ability of BMPs to promote bone formation in grafting procedures and fracture healing. Some studies, have independently reported that sulfated polysaccharides particularly heparin, enhance the osteoblastic differentiation induced by BMPs in vitro, and another study demonstrated that heparin enhanced the bone formation induced by BMP‐2 in vivo. This study was performed to examine adipose stem cell responses to rhBMP‐2 alone and rhBMP‐2 with heparin at 0.25, and 25 μg/㎖ concentrations, respectively, in culture media. Adipose stem cells were cultured for 2, 4, and 8 days toward the osteoblastic differentiation in rhBMP‐2 alone and rhBMP‐2 with heparin at 0.25, and 25 μg/㎖ concentrations, respectively, in culture media. Verification of the stem cell lineage was performed in two ways. The first method was a continuous sequential culture until 5th generation. The second method was using monoclonal antibodies for STRO‐1 and CD 90. Naphthol AS phosphate‐fast blue BB staining for alkaline phosphatase was used for verifying osteoblastic differentiation because Alkaline phosphatase activity had been used as an osteoblastic differentiation marker and degree of osteoblastic activity. Alizarin red staining was also used as an osteoblastic differentiation marker because it quantifies the calcium levels in cells or tissues. During the 5th generation culture, cultured cells actively proliferated, and these cultured cells showed a positive reaction to STRO‐1 and CD90 cell surface molecules. Naphthol AS phosphate‐fast blue BB staining and Alizarin red staining were positive in most samples of each group at 2, and 4 days and positive reaction was proportioned to degree of morphological differentiation. In the concentration of 25 μg/ml of heparin, the ALP activity was highest at the 2nd day in the culture, and then the activities of ALP were decreased significantly at 4, and 8 days. The ALP activity was greatest at the 4th day of the culture, and then decreased significantly at the 8th day in 0 μ g/ml and 0.25 μg/ml of heparin concentrations, Adipose stem cells could be differentiated in rhBMP‐2 in culture media, and the addition of heparin to BMP‐2 promoted differentiation of osteoblasts. Moreover, morphological differentiation was associated with the activity of osteoblasts. This study was shown that, when heparin concentration increases, the early differentiation of the cells was brought about, but the early differentiated cells were rapidly progressed to degenerative changes
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