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        검색결과 25

        1.
        2022.10 구독 인증기관·개인회원 무료
        The decommissioning of a nuclear power plant is a project that consists of several stages, and various technologies are applied when performing various tasks at each stage. And it is essential to secure safety and economic feasibility. As the paradigm has changed due to digital transformation in various industries, digitalization is applied to the life cycle of nuclear power plant from construction, operation and decommissioning project. Element technologies are being developed for decommissioning plan establishment, process design, econtamination method, decommissioning work process, waste management, environmental monitoring and radiation dose simulation. The utilization of digital twin in the decommissioning stage is classified into three categories. ① Process Monitoring (decommissioning work procedure, work progress (plan/actual), real-time work status and etc.) ② Facility Monitoring (real-time sensing and video data monitoring, decommissioning SSCs information, work alarm and etc.) ③ Safety Monitoring (work safety, radiation exposure, fire monitoring, work risk and etc.) A system suitable for the decommissioning stage and work should be developed in consideration of the target of use, development function, and when to create data according to the purpose of the system. Simulation module according to user purpose should be provided. In addition, data-base management should be performed according to the decommissioning characteristics in consideration of the data associated with the existing operating system. The system to be developed should support the project management to comply with the domestic standards and regulations to be determined in the future. This will improve the competitiveness of domestic and foreign markets.
        2.
        2022.10 구독 인증기관·개인회원 무료
        The decommissioning project of NPP is a large-scale project, with various risks. Successful implementation of the project requires appropriate identification and management of risks. IAEA considered risk management “To maximize opportunities and to minimize threats by providing a framework to control risk at all levels in the organization”. Framework-based risk management allows project managers to identify key areas in which action should be taken at an appropriate time. Also, it enables effective management of projects by supporting decision-making on sub-uncertainty. Risk could be categorized according to the source of the risk. This is called Risk Breakdown Structure (RBS), and is documented as a risk assumption register through a risk identification process. IAEA considers various factors when defining risks in accordance with ISO 31000:2009. IAEA SRS No.97 presents a recommended risk management methodology for the strategy and execution stage of the decommissioning project of nuclear facilities through the DRiMa project conducted from 2012 to 2015. The risk breakdown structure classified in DRiMa project is as follows: (1) Initial condition of facility, (2) End state of decommissioning project, (3) Management of waste and materials, (4) Organization and human resources, (5) Finance, (6) Interfaces with contractors and suppliers, (7) Strategy and technology, (8) Legal and regulatory framework, (9) Safety, and (10) Interested parties. They have various prompts for each category. Such a strategy for dealing with risks has negative risks (threats) or positive risks (opportunities). The negative risks are as shown in avoid, transfer, mitigate and accept. On the other side, the positive risks are as shown in exploit, share, enhance and accept. During the decommissioning, a contingency infrastructure is needed to decrease the probability of unexpected events caused by negative risks. The contingency infrastructure of decommissioning project includes organization, funding, planning, legislation & regulations, information, training, stakeholder involvement, and modifications to existing programs. Since all nuclear facilities have different environmental, physical or contamination conditions, risks and treatment strategies should also be applied differently. This risk management process is expected to proceed at the stage of establishing and implementing a detailed plan for the decommissioning project of each individual plant.
        3.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고용량 배터리에 대한 요구가 증가에 따라 기존 음극재보다 높은 용량(3,860 mAh/g)과 낮은 전기화학적 전위(– 3.040 V)를 갖는 리튬 금속 기반 음극재에 대한 연구가 활발하게 이루어지고 있다. 본 연구에서는 수열 합성을 통해 제작된 아나타제(anatase) 타입의 TiO2 나노 입자 기반한 PVdF-HFP/TiO2 복합체를 리튬 금속 음극의 계면 보호층으로 적용하였다. 결정구조 및 형상 분석을 통해 유/무기-리튬 나노복합체 박막의 형성을 확인하였다. 또한, 전지화학 테스트(사이클 테스트 및 전압 프로파일)를 통해 리튬 금속 음극의 전기화학 성능은 복합체 보호막이 TiO2 10 wt%, 코팅 두께 1.1 μm의 조건에서 가장 개선된 전기화학적 성능(콜롱 효율 유지: 77 사이클 동안 90% 이상) 발현을 확인하였다. 이를 통해, 처리하지 않은 리튬 전극 대비 본 보호층에 의한 리튬 금속 음극의 성능 안정화/개선 효과가 검증되었다.
        4,000원
        4.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 인공지능 연구개발과정에 많은 인적자원이 필요함을 인지하고 현 개발방식 고려할 사항에 대해 논의한다. 결론적으로 인공지능 개발의 효율성 향상을 위해서는 소수의 관리자와 많은 일반작업자들의 분업화가 이루어져야 가능하며, 이는 마치 일종의 경공업의 형태와 유사하다고 생각된다. 따라서 본 연구진은 컴퓨터라는 기계장치로 데이터라는 디지털 자원을 다루어 생산의 효율성 을 높이는 인공지능 개발과정을 4차산업시대의 디지털 경공업이라고 명명한다. 이전 산업혁명시대에서 경험한 것과 마찬가지로 인 적자원을 효율적으로 배분화하고 활용한다면 디지털 경공업은 2차산업혁명 못 지 않는 발전을 기대할 수 있을 것이며, 이를 위한 인 력양성이 시급하다고 판단된다.
        4,200원
        5.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To utilize Malus pruniforia Borkh. as a functional material, cold-water (CW), hot-water (HW), and 70% ethanol (EtOH) extracts were prepared, and their antioxidant and anti-inflammatory activities were compared. The antioxidant activity of the HW extract evaluated by ABTS and DPPH radical scavenging and FRAP activity was significantly effective. The total polyphenol content of the HW extract was also higher by 15.5±0.7 mg GAE/g extract compared to other extracts. The EtOH extract showed significantly decreased TNF-α (39.8%), IL-6 (65.5%), and NO (34.9%) levels in RAW 264.7 cells compared to the LPS-induced control group. The levels of IL-6 (21.1%) and IL-8 (19.3%) were significantly decreased by treatment of EtOH extract in HaCaT keratinocytes induced with TNF-α and IFN-γ. The UHPLC-MS results indicated that the EtOH extract might have chlorogenic acid and phlorizin as the major compounds. This was validated using HPLC-DAD, which showed that the EtOH extract had higher levels of chlorogenic acid and phlorizin (1,185±58 and 470±10 μg/g extract, respectively). In conclusion, the present study suggested that the anti-inflammatory activity of the EtOH extract was more effective than the CW and HW extracts, and chlorogenic acid and phlorizin could be used as indicator compounds and functional substances.
        4,000원
        6.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        리튬금속전지(LMB)는 매우 큰 이론 용량을 갖지만 단락(short circuit), 수명 감소 등을 야기하는 덴드라이트(dendrite) 가 형성되는 큰 문제점을 갖고 있다. 본 연구에서는 poly(dimethylsiloxane) (PDMS)에 graphene oxide (GO) nanosheet를 고르게 분산시킨 PDMS/GO 복합체를 합성하였고 이를 박막 형태로 코팅하여 덴드라이트의 형성을 물리적으로 억제할 수 있는 막의 효과를 이끌어내었다. PDMS의 경우, 그 자체로는 이온 전도체가 아니기 때문에 리튬 이온의 통로를 형성시켜 리튬 이온의 이동을 원활하게 하기 위하여 5wt% 불산(HF)으로 에칭하여 PDMS/GO 박막이 이온전도성을 가질 수 있도록 하였다. 주사전자현미경(scanning electron microscopy, SEM)을 통해 전면 및 단면을 관찰하여 PDMS/GO 박막의 형상을 확인하였다. 그리고 PDMS/GO 박막을 리튬금속전지에 적용하여 실시한 배터리 테스트 결과, 100번째 사이클까지 쿨롱 효율(columbic efficiency) 이 평균 87.4%로 유지되었고, 박막이 코팅되지 않은 구리 전극보다 과전압이 감소되었음을 전압 구배(voltage profile) 를 통해 확인하였다.
        4,000원
        7.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        리튬 덴드라이트의 효과적인 억제를 위해 유/무기 복합체를 리튬메탈 전극의 보호층으로 사용하였다. 유기물로는 PVDF-HFP가 사용되었으며 무기물로는 TiO2가 사용되었다. 유기물로 사용된 PVDF-HFP는 높은 유연성을 가지는 고분자로서 무기물의 matrix 역할을 하며, 무기물로 사용된 TiO2 나노입자는 보호막의 기계적 강도와 이온전도성을 향상시켜주는 역할을 하였다. 합성된 보호막은 SEM, AFM, XRD를 통하여 PVDF-HFP matrix에 TiO2가 잘 분산되어 있는 형태인 것을 확인할 수 있 었다. 또한 전기화학적 분석 결과, 향상된 기계적 물성과 이온전도성으로 인해 polymer-inorganic composite은 비교 샘플(untreated 와 PVDF-HFP 보호층) 대비 100번째 사이클까지 80%의 높은 쿨롱 효율 및 20 mV 미만의 낮은 과전압을 나타내었다.
        4,000원
        9.
        1998.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orchardgrass의 종자배양에서 캘러스형성과 식물체 재분화에 적합한 조건을구명하기 위하여 품종간의 차이와 배지조성 및 생장조절물질의 조성 등에 대한 일련의 실험을 수행한 바, 공시품종중 "Amba"의 식물체 재분화율이 가장 높았고, $N_6$ 수식 이미지 배지가 MS, $B_5$ 수식 이미지 배지보다 종자에서 형성된 캘러스 생체중이 무거웠으며, 식물체 재분화율도 높게 나타났다. 또한 3 mg/L의 dicamba가 첨가된 배지에서 형성된 캘러스를 재분화배지에 이식하였을 때 식물체 재분화율이 30%로 가장 높게 나타났다.ㅍ
        4,000원
        10.
        2017.05 서비스 종료(열람 제한)
        Background : Cellular oxidative stress as reactive oxygen species (ROS), whether produced endogenously as a consequence of normal cell functions or derived from external sources, pose a constant threat to cells living in an aerobic environment as they can result in severe damage to DNA, protein, and lipids. The effects of Valeriana fauriei extract and fractions on hydrogen peroxide-induced neuronal cell damage are studied. Methods and Results : Oxidative stress plays an important role in the pathological process of neurodegenerative diseases. Valeriana fauriei extract (VFE) and EA fractions (VFEA) was investigated total phenolic contents using method. VFE of total phenolic contents had 2.54 ± 0.01 mg/g, also, VFEA had a 18.78 ± 0.03 mg/g. High phenolic content of the VFEA is expected to better the inhibition of oxidative stress. VFE and VFEA were experimented to inhibit ROS induced 200 μM 3-morpholinosydnonimine (SIN-1). VFE of inhibit SIN-1 induced-ROS dose dependently and signficantly. In addition, VFEA inhibition was also dose dependant and significant. Moreover, The treatment of SH-SY5Y and SK-N-SH cells with VFEA significantly reduced hydrogen peroxide-induced generation of intercellular ROS. Conclusion : From the above results, we may suggest that VFEA might have useful as a material for functional food and pharmaceutics for the pathological process of neurodegenerative diseases.
        11.
        2017.04 KCI 등재 서비스 종료(열람 제한)
        This study provides basic data for the cost operating strategy of forest welfare infra facilities. We use the Price-Sensitivity Measurement technique (PSM) for a forest welfare infra facility (healing forest, wood camping, forest leisure sport, etc.). In addition, we conduct a survey in the four target locations (Kyung-gi, Kyung-sang, Chung-cheong, and Jeolla) and receive answer from 390. The results show that higher the price of present infra facilities, higher the price sensibility. The forest welfare infra facilities we include are healing forest 1,894 won, wood camping 5,625 won, mtb park 9,530 won, mountain horseback riding 14,556 won, paragliding 20,252 won, mountain ski 3,075won. However, we investigate zip-lines at lower than current price levels.
        12.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        Background: Prenatal exposure to infectious and/or inflammatory insults can increase the risk of developing neuropsychiatric disorder such as bipolar disorder, autism, and schizophrenia later in life. We investigated whether Valeriana fauriei (VF) treatment alleviates prepulse inhibition (PPI) deficits and social interaction impairment induced by maternal immune activation (MIA).Methods and Results: Pregnant mice were exposed to polyriboinosinic-polyribocytidilic acid (5㎎/㎏, viral infection mimic) on gestational day 9. The adolescent offspring received daily oral treatment with VF (100㎎/㎏) and injections of clozapine (5㎎/㎏) for 30 days starting on the postnatal day 35. The effects of VF extract treatment on behavioral activity impairment and protein expression were investigated using the PPI analysis, forced swim test (FST), open field test (OFT), social interaction test (SIT), and immunohistochemistry. The MIA-induced offspring showed deficits in the PPI, FST, OFT, and SIT compared to their non MIAinduced counterparts. Treatment with the VF extract significantly recovered the sensorimotor gating deficits and partially recovered the aggressive behavior observed in the SIT. The VF extract also reversed the downregulation of protein expression induced by MIA in the medial prefrontal cortex.Conclusions: Our results provide initial evidence of the fact that the VF extract could reverse MIA-induced behavioral impairment and prevent neurodevelopmental disorders such as schizophrenia.
        13.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        β amyloid protein (Aβ) plays a critical role in the pathogenesis of Alzheimer's disease (AD) and possibly in Aβ -induced mitochondrial dysfunction and oxidative stress. Aβ can directly cause reactive oxygen species (ROS) production. Overproduction of ROS is considered to be involved in the pathogenesis of neurodegeneration of AD. Here, we investigated 9 kinds of ramie (Boehmeria nivea, (L.) Gaud., BN; hereafter denoted as BN) for their protective action against oxidative stress in a cellular system using C6 glial cells. We observed loss of cell viability and high levels of ROS generation after treatment with hydrogen peroxide (H2O2) and Aβ25-35. However, treatments with BN extracts led to an increase in cell viability and decrease in ROS production induced by H2O2 and Aβ25-35. In particular, the extracts of BN-01 (seobang variety from Seocheon) and BN-09 (local variety from Yeonggwang) showed excellent anti-oxidative properties. This indicates that BN extracts could prevent neurodegeneration by reducing oxidative stress in cells.
        14.
        2015.07 서비스 종료(열람 제한)
        Ramie (Boehmeria nivea L.) is a hardy perennial herbaceous plant of the Urticaceae family and has been grown as a fiber crop in several countries including Korea for many centuries. Ramie leaves also have been traditionally used as a major ingredient of a type of rice cake called ‘Song-pyun’ in the Southwest area of Korea, especially Yeong-Gwang province. Despite its economic importance, the molecular genetics of ramie have not been studied in detail yet. Genetic resources of ramie were widely collected from domestic local sites by Bioenergy Crop Research Center (RDA) and Yeong-Gwang Agricultural Technology Center. For the systematic and efficient management of the genetic resources, we developed SSR (simple sequence repeat) markers of ramie. To do this, we generated microsatellite-enriched genomic DNA libraries using magnetic bead hybridization selection method. 247 non-redundant contigs containing SSR motif were generated using nucleotide sequences of 376 clones from the libraries. Primer sets were designed from the flanking sequences of the repeat motif. Finally, we selected 10 SSR markers, possibly showing polymorphism among the genetic resources. Results on the genotype analysis of the ramie genetic resources using the SSR markers will be presented.
        15.
        2015.05 서비스 종료(열람 제한)
        To evaluate therapeutic efficacy of aldose reductase (AR) inhibition, the leaves of Aster yomena were tested for inhibition of AR. The stepwise polarity fractions of A. yomena were tested. Among them, the n-BuOH fraction showed highest activities against AR inhibition. Our results demonstrated that A. yomena could be a worthy natural source source for curing against diabetic complications.
        16.
        2015.05 서비스 종료(열람 제한)
        Content analysis of loliolide in the leaves of Boehmeria nivea (Bn) collected from different region during four months (June, July, August, and September) was conducted by HPLC. The content of loliolide was detected in the leaves of B. nivea from Bns-2, -7, -10, -23, -38, -41, -67, -76, and -90 in June (5.02, 6.35, 6.93, 5.89, 4.31, 4.24, 4.91, 5.12, and 5.46 mg/g, respectively), July (4.32, 6.42, 7.72, 7.97, 4.05, 4.32, 5.65, 6.67, and 5.39 mg/g, respectively), August (3.52, 5.17, 3.90, 4.27, 3.26, 4.72, 3.82, 3.30, and 3.31 mg/g, respectively), and September (7.04, 7.25, 7.43, 7.86, 6.76, 6.38, 7.60, 6.79, and 4.77 mg/g, respectively). Among them, the highest content of loliolide was found in Bn-23 and in September. These results may be useful in determining the optimal harvest time at which phytochemical reaches a maximum level.
        17.
        2015.05 서비스 종료(열람 제한)
        To evaluate therapeutic efficacy of aldose reductase (AR) inhibition, the seeds of Perilla frutescens var. japonica (PF) were tested for inhibition of AR. The stepwise polarity fractions of PF were tested. The CH2Cl2 and EtOAc fractions showed highest activities (IC50 5.47 and 3.63 μg/mL, respectively). Compounds 1-5 were isolated from the CH2Cl2 and EtOAc fractions by silica-gel and LH-20 Sephadex. Their structures were elucidated as β-sitosterol (1), diosmetin (2), kaempferol (3), luteolin (4), and apigenin (5). Compounds 1-5 were exhibited AR inhibitory. Among them, luteolin (4) and apigenin (5) exhibited AR inhibitory activities (IC50 0.40 and 1.10 μg/mL, respectively). Our results demonstrated that PF could be a worthy natural source for curing against diabetic complications.
        18.
        2014.07 서비스 종료(열람 제한)
        Fusarium head blight (FHB) is a major disease problem on wheat and barley around the world. F. graminearum produces trichothecenes mycotoxins such as nivalenol (NIV), deoxynivalenol (DON), and zearalenone (ZEA). The objectives of this study were to survey the natural occurrence of FHB and mycotoxins of 32 Korean wheat cultivars grown in 2011-2012 seasons at the National institute of crop science, Iksan, Korea. There was great deal of rainfall and high humidity during flowering time in May 2011. FHB incidence was counted by Fusarium infected spikes per square meter. The samples of 32 wheat cultivar were collected. The grain and flour samples were to analysis for DON and NIV by gas chromatography and ZEA by high performance liquid chromatography. The result showed that the average of FHB incidence(%) per square meter in 2011 and 2012 were 4.2%, 0.5% respectively. There were significant cultivar differences for FHB incidence ranged from 0% to 24% in 2011. All of 32 wheat cultivars contained 9-2088 ng/g for NIV and ten wheat cultivars contained 5.7-8.5 ng/g for ZEA. In addition, DON concentration of Tapdong, Shinmichal1, and Hanbaek were 217, 35 and 683 ng/g respectively. However, the grain and flour sample harvested in 2012 showed that lower FHB incidence and NIV concentration. These results showed that the 32 wheat cultivars harvested in 2011 were heavily contaminated with Fusarium mycotoxins (NIV, DON, ZEA).
        19.
        2014.07 서비스 종료(열람 제한)
        Acanthopanax species is known commonly as Siberian ginseng, touch-me-not, devil’s shrub, prickly eleutherococc, eleutherococc and wild pepper. A diverse group of chemical compounds isolated from Acanthopanax species was named ‘eleutherosides’. Among eleutherosides, eleutherosides B and E were widely known in Acanthopanax species. Acanthopanax species are cultivated and grow wild in a various area of Korea and have a variety of pharmacological effects. But, there are a lot of difficulties on producing excellent Acanthopanax species, according to the cultivated method is different pharmacological ingredients. This study, therefore, analyzed eleutherosides B and E in A. divaricatus and A. koreanum by different fertilizer ratio using HPLC. We will be investigated a high content of eleutherosides B and E by different fertilizer ratio and suggest an efficient fertilizer ratio of A. divaticatus and A. koreanum. All samples of A. divaricatus and A. koreanum were collected at Yeongcheon Agricultural Technology & Extension Center, Yeongcheon, Korea. The sample was prepared by upper and lower parts. The fertilizer ratio are N-P-K(10.5-8.5-8.5: 50 kg/10a), 2N-P-K (21-8.5-8.5: 50 kg/10a), N-2P-K (10.5-17-8.5: 50 kg/10a), N-P-2K (10.5-8.5-17: 50 kg/10a), and 2N-2P-2K (21-17-17: 50 kg/10a), respectively. To analyze eleutherosides B and E, 5 g of A. divaricatus and A. koreanum was extracted with 50% MeOH (3 × 100 ml) by reflux and evaporated in vacuo. The residue was dissolved in 1 ml of MeOH. The resulting solution was used for HPLC analysis. HPLC separation of eleutherosides B and E for qualitative and quantitative analysis was performed using a reverse phase system. A Discovery®C18 (4.6 × 250 mm, 5 μm) column was used with a mobile phase that consisted of water and acetonitrile. A gradient solvent system of water and acetonitrile (90:10 to 70:30 for 20 min) was used for the elution program. UV detection was conducted at 350 nm. The injection volume was 10 μl and the flow rate was 1 ml/min. All injections were performed in triplicate. The different fertilizer ratio yielded total eleutherosides B and E contents of 4.417-6.905 and 3.652-7.227 mg/g in the upper and lower parts of A. divaricatus, respectively. In A. koreanum, the total eleutherosides B and E contents were 4.591-10.108 and 3.834-9.079 mg/g in the upper and lower parts, respectively. The best conditions to increase eleutherosides B and E content in A. divaricatus was determined to be with N-2P-K fertilizer ratio, on the other hand, in A. koreanum was 2N-2P-2K fertilizer ratio.
        20.
        2014.07 서비스 종료(열람 제한)
        Ramie (Boehmeria nivea L. Gaudich.) is a hardy perennial herbaceous plant of the Urticaceae family and has been grown as a fiber crop in several countries including Korea for many centuries. Ramie leaves also have been traditionally used as a major ingredient of a type of rice cake called ‘Song-pyun’ in the Southwest area of Korea, especially Yeong-Gwang province. Despite its economic importance, the molecular genetics of ramie have not been studied in detail yet. Genetic resources of ramie were widely collected from domestic local sites by Bioenergy Crop Research Center (RDA) and Yeong-Gwang Agricultural Technology Center. For the systematic and efficient management of the genetic resources, we developed microsatellite molecular markers of ramie. To do this, we generated microsatellite-enriched genomic DNA libraries using magnetic bead hybridization selection method. 216 contigs containing microsatellite repeat motif were generated using nucleotide sequences of 376 clones from the libraries. Primer sets were designed from the flanking sequences of the repeat motif. Finally, we selected 26 microsatellite markers, possibly showing polymorphism among the genetic resources. Results on the genotype analysis of the ramie genetic resources using the microsatellite markers will be presented.
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