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        검색결과 48

        2.
        2023.11 구독 인증기관·개인회원 무료
        Decommissioning waste is generated with various types and large quantities within a short period. Concrete, a significant building material for nuclear facilities, is one of the largest decommissioning wastes, which is mixed with aggregate, sand, and cement with water by the relevant mixing ratio. Recently, the proposed treatment method for volume reduction of radioactive concrete waste was proven up to scale-up testing using unit equipment, which involved sequentially thermomechanical and chemical treatment. According to studies, the aggregate as non-radioactive material is separated from cement components with contaminated radionuclides as less than clearance criteria, so the volume of radioactive concrete waste is decreased effectively. However, some supplementation points were presented to commercialize the process. Hence, the process requires efficiency as possible to minimize the interface parts, either by integration or rearranging the equipment. In this study, feasibility testing was performed using integrated heating and grinding equipment, to supplement the possible issue of generated powder and dust during the process. Previously, heat treatment and grinding devices were configured separately for pilot-scale testing. But some problems such as leakage and pipe blockage occurred during the transportation of generated fine powder, which caused difficulties in maintaining the equipment. For that reason, we studied to reduce the interface between the equipment by integrating and rearranging the equipment. To evaluate the thermal grinding performance, the fraction of coarse and concrete fines based on 1mm particle size was measured, and the amount of residual cement in each part was analyzed by wet analysis using 4M hydrochloric acid. The result was compared with previous studies and the thermomechanical equipment could be selected to enhance the process. Therefore, it is expected that the equipment for commercialization could be optimized and composed the process compactly by this study.
        3.
        2023.10 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are used to produce raw materials by applying solid culture technology using grains. But there are various problems such as low production efficiency and cross-contamination. Solvum Co., Ltd. conducted research on liquid culture technology to develop a method that can overcome these shortcomings of solid culture technology. We conducted research and development on using Beauveria bassiana 331R to observe the culture according to the seed inoculation amount in a 30 L fermenter, it was carried out at 1.0 % (v/v) and 10.0 % (v/v). Although there was a difference of 1 day, 1.0 %(v/v) seed inoculation was observed to be more than twice that, and active blastospores and yield were observed at over 95.0 %. As a results, it was determined that cost and efficient production would be possible during the culture process in mass production. Based on these experiments, a 300 L fermenter was cultured with 1.0 % (v/v) seed inoculation, resulting in a yield of 1.24E+09 CFU/mL on the 6th day of cultivation. As a result of freeze-drying using the final culture medium, it was confirmed that the production yield was improved by 113.0 % compared to the control.
        4.
        2023.10 구독 인증기관·개인회원 무료
        Cryptotympana atrata belongs to the family Cicadidae, has long been recognized as a damaging plant-sucking pest, and is distributed in East Asian countries. In addition, their cries cause direct harm to us through noise pollution and also reported twig damage in the forest environments. In this study, we isolated strains of the entomopathogenic fungus Metarhizium that occurred from C. atrata collected this year. Here, we provide the morphological character and molecular phylogenetic relationship of this species. This is the first record of the entomopathogenic fungus Metarhizium viridulum isolated from C. atrata in Korea and provides a candidate strain with potential use for biological agents.
        5.
        2023.05 구독 인증기관·개인회원 무료
        Laser cutting has been recognized as one of key techniques in dismantling nuclear power plants as it has several advantages such as a remote operation and a reduced secondary waste. However, it generates a significant amount of aerosols that can pose a health risk to workers and further induce environmental pollution during the cutting operation. Thus, understanding the aerosol characteristics generated by the laser cutting is crucial for implementing an effective cutting operation and reducing the exposure to these hazardous particles. In this work, we established a methodology to collect the aerosols and investigate their properties in the laser cutting operation. We built an integrated laser cutting system for aerosol analyses, consisting of a high-power laser cutting module, a metal sample holder, an aerosol collector, and a closed chamber. We expect that this system will offer an opportunity for in-depth understanding of the aerosol properties, by connecting it with desired type of aerosol analysis platforms, and further safe dismantling operation of the nuclear power plants.
        6.
        2023.05 구독 인증기관·개인회원 무료
        After Fukushima nuclear power plant accident in 2011, Concerns about accident of spent fuel pool increase. In Korea, the time of saturation of spent fuel pool is coming, but regulatory measures and safety evaluation are insufficient when occurring spent fuel pool accident. Thus, it is necessary to review of spent fuel pool accident in foreign countries to establish regulatory measures and safety evaluation of spent fuel pool accident suitable for domestic spent fuel pool. Therefore, we reviewed spent fuel pool accident that occurred at Fukushima Unit 4, SONGS Unit 2 and PAKS. In Japan, spent fuel pool accident occurred at Fukushima NPP in 2011. Tsunami was cause of the accident. Station Black Out occurred at Fukushima NPP and Emergency Diesel Generator lost their functions due to Tsunami. As a result, Loss of cooling happened in spent fuel pool at Fukushima NPP. For Unit 4, wall of spent fuel pool in Unit 4 was damaged due to hydrogen explosive, so loss of coolant in spent fuel pool of Unit 4 occurred. After the accident, the temperature of spent fuel pool increases to 75°C, but there was no damage to the spent fuel. In USA, spent fuel pool accident occurred at SONGS Unit 2 in 2013. The debris of nearby ocean is cause of the accident. The debris entered the system through a damaged Salt Water Cooling pump suction strainer. The debris obstructed flow through the Component Cooling Water heat exchanger and operation of Salt Water Cooling. The maximum spent fuel pool temperature during this event was 25.6°C. It was a value that satisfied the technical specifications of the SONGS NPP. In Ukraine, spent fuel pool accident occurred at PAKS in 2003. Unintentionally opened valve of cleaning tank is cause of the accident. Loss of coolant occurred in spent fuel pool of PAKS. Due to loss of coolant, spent fuels were exposed to the vapor state atmosphere, and oxidation occurred in the cladding tube of the spent fuel that rose to 1,400°C. In this study, Review of spent fuel pool accident in major foreign countries was conducted as basic studies for establishing regulatory measures and safety evaluation of spent fuel pool in Korea. Causes of each accident were different by structure of spent fuel pools. Result of this study will be contributed to establish safety measures of spent fuel pool accident suitable for domestic spent fuel pool facility.
        8.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 몇가지 전처리제 및 보존용액 처리가 국내 육성 절화 프리지아 ‘Gold Rich’의 수확후 절화수명과 개화 품질에 미치는 영향을 구명하고자 수행하였다. 10% sucrose, 200mg・L-1 Al2(SO4)3, 200mg・L-1 GA3, 150mg・L-1 citric acid가 혼용된 전처리 용액에서 절화 관상 기간 동안 수분 흡수량과 생체중은 유의적으로 증가한 것으로 조사되었지만 절화수명에는 큰 영향을 미치지 않았다. 보존용액으로 5% sucrose와 살균제인 300mg・L-1 8-HQ를 혼용 처리하였을 때 절화수명 연장(1일 이상), 높은 개화율(82.3~89.1%) 및 만개율(71.5~84.2%) 등의 개화 품질이 향상되었다. 이러한 결과들을 통해 10% sucrose, 200mg・L-1 Al2(SO4)3, 200mg・L-1 GA3, 150mg・L-1 citric acid를 혼합한 전처리제와 5% sucrose, 300mg・L-1 8-HQ를 혼합한 보존용액 처리는 절화수명 연장, 개화율 및 만개율 증가에 효과적일 것이라고 판단된다. 특히, sucrose가 포함된 보존용액은 절화 프리지아 ‘Gold Rich’ 의 상품성 향상에 있어 매우 유용할 것이다.
        4,000원
        10.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the effect of moderate- and high-intensity resistance training on hippocampal neurotrophic factors and peripheral CCL11 levels in high-fat diet (HFD)-induced obese mice. C57/black male mice received a 4 weeks diet of normal (control, CON; n = 9) or a high-fat diet (HF; n = 27) to induce obesity. Thereafter, the HF group was subdivided equally into the HF, HF + moderate-intensity exercise (HFME), and HF + high-intensity exercise (HFHE) groups (n = 9, respectively), and mice were subjected to ladder-climbing exercise for 8 weeks. The hippocampal brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) levels were significantly lower in the HF group than in the CON group (p < 0.05). In addition, in the HFME and HFHE groups were significantly higher than in the HF group (p < 0.05). The peripheral CCL11 levels were significantly higher in the HF group than in the CON group (p < 0.05). In addition, in the HFME and HFHE groups were significantly lower than in the HF group (p < 0.05). However, there was no significant difference according to the exercise intensity among the groups. Collectively, these results suggest that obesity can induce down-regulation of neurotrophic factors and inhibition of neurogenesis. In contrast, regardless of exercise intensity, resistance training may have a positive effect on improving brain function by inducing increased expression of neurotrophic factors.
        4,000원
        14.
        2017.10 구독 인증기관·개인회원 무료
        Recently, hair loss regarded as a mere means of middle-aged men due to stress and environmental pollution. The market for hair loss in Korea is about four trillion won and it is growing continuously. It is mainly made by mixing natural extracts such as medicinal plant. The purpose of this study was to investigate the effects of 70% ethanol extracts of Phellinus linteus on the growth of fibroblasts, dermal papilla cells and lipid precursors, We want to try to make a materialization. The 70% ethanol extract of P. linteus on the cell viability of Human follicle dermal papilla cell (HFDPC), adipocyte (3T3-L1), fibroblast (CCD-986sk). The result the cell viability of HFDPC was increased according to the contents of ethanol extract of P. linteus. But the 70% ethanol extract of P. linteus showed weak inhibit activity in CCD-986sk cell growth. Also, the 70% ethanol extract of P. linteus did not inhibit the growth of 3T3-L1 cells. As a result of this study, in-vitro hair growth activity of herbal medicines for hair material development was not shown to be toxic to HFDPC and 3T3-L1 cell. As a result, the 70% ethanol extracts of P. linteus have potential to developing hair-related product. Acknowledgement : This research was supported by the Ministry of Trade, Industry & Energy(MOTIE), Korea Institute for Advancement of Technology(KIAT) through the Encouragement Program for The Industries of Economic Cooperation Region(R0005473)
        18.
        2014.10 구독 인증기관·개인회원 무료
        Insects impact human health through vector-borne diseases and cause major economic loses through damaging crops and stored agricultural products. Insect-specific growth regulators (IGR) represent attractive control agents because of their safety to the environment and humans. Here, we report identification of plant compounds that are antagonists of the insect-specific juvenile hormone (PJHANs), using the yeast two hybrid system transformed with the mosquito JH receptor as a reporter assay. We show that these compounds act by inhibiting larval growth and reproduction in mosquitoes. We also demonstrate that PJHANs affect the JH receptor, Methoprene-tolerant (Met), by disrupting its complex with CYCLE, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants, Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Two of these diterprenes affect Met function, leading to reduction in expression of Met target genes and causing retardation of follicle development in mosquito ovaries. Developing potent compounds counteracting JHaction (JH antagonists) would find a wider range of control applications. However, so far such JH antagonists have not been developed. Here, we report the discovery of potent JH antagonists in plants, which represents an innate resistance mechanism of plants against insect herbivores. These newly discovered plant JH antagonist compounds could be used as the starting material for developing novel insecticides.
        19.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of different levels of soybean curd residue as an ingredient of TMR on growth performance and carcass characteristics of Holstein steers. Twenty four Holstein steers of 7 months age(average body weight 274.6 kg) were randomly allocated to 3 experimental groups, which contained 8animals per group during 15-months feeding trial. The treatments composed of the group fed concentrate and rice straw separately (Control), the group fed TMR containing low levels of soybean curd (T1), the group fed TMR containing high levels of soybean curd residue (T2). Body weight and average daily gain were not significantly different among the treatment groups during the feeding trial periods. Feed intake was not differ among treatment groups, but feed conversion ratio was significantly higher in T2 group compared to T1 group during late fattening stage (p<0.05). However, it was not different in overall average. According to the yield traits, carcass weight of control, T1 and T2 were 466.4, 451.1 and 460.1 kg, respectively. Back fat thickness, rib eye area and yield index were not different among the groups. The marbling score, meat color, texture and maturity in quality traits were not different among the treatment groups, but fat color was significantly higher in T2 group compared to T1 group (p<0.05). The quality grade (1+:1:2:3, NO.) tended to be higher for T1(0:2:1:5) and T2 (0:1:4:3) compared with the control (0:0:3:5). Therefore, these results indicated that TMR with soybean curd residue may be appropriate the growth performance and carcass characteristics of Holstein steers.
        4,000원
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