• 제목/요약/키워드: Natural source

검색결과 2,087건 처리시간 0.03초

전자기록의 출처확인 지원전략 (A Verification Strategy for the Origin of Electronic Records)

  • 송병호
    • 기록학연구
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    • 제25호
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    • pp.47-89
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    • 2010
  • 전자기록을 잘 관리한다는 것은 결국 기록이 필요할 때 믿고 사용할 수 있도록 하려는 것이다. 전자기록은 진본성과 무결성면에서 취약점이 있고 현행 표준이나 방법들은 이에 대한 보완관리를 목적으로 해서 개발되었다. 그러나 전자기록은 진본성과 무결성을 독립적으로 고려하기 힘들므로 본 논문에서는 출처라는 개념을 도입하여, 출처확인이 우선 잘 이루어지는 지원 전략을 논의하였다. 이러한 측면에서 볼 때 현행 방식들은 검증 정보 수록 및 확인에 태만하며 장기검증에 문제가 있고 출처확인이 안되는 기록에 대한 대응책 마련이 미흡하다. 본 논문에서는 이러한 점을 개선하기 위하여한 출처확인에 필요한 요소들을 설명하고, 장기 검증이 가능하도록 전자기록보존포맷을 고정부와 변동부로 나누고 출처는 고정부에서만 확인하는 새로운 검증방법을 제안하며, 출처확인이 실패해서는 안되는 중요 기록물에 대하여 예방, 회피, 탐지복원 방안을 제시한다.

Optimization of Phototrophic Growth and Lipid Production of a Newly Isolated Microalga, Desmodesmus sp. KAERI-NJ5

  • Joe, Min-Ho;Kim, Dong-Ho;Choi, Dae Seong;Bai, Suk
    • 한국미생물·생명공학회지
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    • 제46권4호
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    • pp.377-389
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    • 2018
  • In this study, a novel microalgal strain, Desmodesmus sp. KAERI-NJ5, was isolated, identified, and evaluated as a candidate for biodiesel feedstock. In a preliminary study, the effects of four general microalgal growth factors, including temperature, pH, light intensity, and concentration of nitrogen source ($KNO_3$), on the microalgal photoautotrophic growth were evaluated. With the exception of light intensity, the growth factors needed to be optimized for the microalgal biomass production. Optimization was done using response surface methodology. The optimal conditions for biomass production were pH 6.54, $27.66^{\circ}C$, and 0.52 g/l $KNO_3$. The biomass production at the optimal conditions was 1.55 g/l, which correlated well with the predicted value of 1.5 g/l. The total lipid and fatty acid methyl ester contents of the cells grown at the optimal conditions were 49% and 21.2% of cell dry weight, respectively. To increase the lipid content of the biomass, microalgae were challenged by nitrogen starvation. Enhancement of total lipid and fatty acid content up to 52.02% and 49%, respectively, were observed. Lipid analysis of the nitrogen-starved cells revealed that C16 and C18 species accounted for 95.9% of the total fatty acids. Among them, palmitic acid (46.17%) and oleic acid (39.43%) dominantly constituted the algal fatty acids. These results suggest Desmodesmus sp. KAERI-NJ5 as a promising feedstock for biodiesel production.

국내산 구아바(Psidium guajava L.) 잎 추출물의 항산화 활성 및 간세포 보호효과 (Antioxidative and Hepatocyte Protective Effects of Guava (Psidium guajava L.) Leaves Cultivated in Korea)

  • 천원영;서동연;김영화
    • 한국식품영양학회지
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    • 제32권1호
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    • pp.33-40
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    • 2019
  • The purpose of this study was to evaluate the antioxidant and hepatocyte protective effects of guava (Psidium guajava L.) leaves cultivated in Korea. The contents of the total polyphenol of the extract was 271.57 mg gallic acid equivalent (GAE)/g residue. Antioxidant activities of leaf extract were evaluated by examining the free radical scavenging ability. 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ${\alpha}-{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) free radical scavenging activities of the extract were 1133.23 mg trolox equivalent antioxidant capacity (TEAC)/g residue and 721.68 mg TEAC/g residue, respectively. The hepatocyte protective effect of guava leaf extract was examined in HepG2 cells. Against tert-butyl hydroperoxide (TBHP), the viability of HepG2 cells were increased by the treatment of leaf extract. In addition, guava leaf extract led to the inhibition of reactive oxygen species (ROS) generated in HepG2 cells. The leaf extract increased the activity of glutathione (GSH), glutathione reductase (GR), and glutathione peroxidase (GPx) against oxidative stress. These results suggested that guava leaves might be regarded as a potential source natural antioxidant and a hepatoprotective material.

MATLAB_SIMULINK를 이용한 풍력 발전 시뮬레이터 개발 (Development of wind power simulator using MATLAB SIMULINK)

  • 박원현;미흐렛 게브레스랄새;감지현;변기식;김관형
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2016년도 추계학술대회
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    • pp.665-667
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    • 2016
  • 최근 화석연료의 고갈 및 환경문제로 인해 신재생 에너지에 대한 관심이 해마다 증가하고 있다. 신재생에너지는 깨끗하고 재사용이 가능한 에너지원으로 풍력과 태양광을 이용한 방법이 대표적이다. 이들 중 풍력 발전시스템은 자연의 바람을 이용하여 바람의 운동에너지를 전기에너지로 변환하는 방식이다. 기존에는 풍력 발전시스템을 구현하여 풍동실험을 하기 위해 실제 풍력과 유사한 환경을 구성하여 풍동실험을 하였다. 하지만, 이러한 풍동실험을 구성하기에는 비용이 커지는 문제가 발생한다. 본 논문에서는 이러한 풍동실험을 모터와 발전기를 이용한 테스트 베드를 구성하여 실험할 때 실제 풍동실험에서 발전기의 특성을 고려하여 모터를 제어함으로서 풍동실험과 유사한 결과를 얻고자한다.

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경복궁의 전각 배치에 대한 풍수적 해석 -팔택론의 관점에서 본 북궐도형 분석을 중심으로- (Feng shui analysis on the Layout of the building in Gyeongbokgung Palace -Focus on the analysis of Bukgwoldohyeong in the Paltaekron's point of view-)

  • 이호선;한동수
    • 건축역사연구
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    • 제28권3호
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    • pp.7-18
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    • 2019
  • This study analyzed "Bukgwol Dohyeong (Drawing Plans for the Northern Section of Gyeongbokgung Palace)", which is an important source material for the restoration of the palace, by applying Paltaekron, the geomantic principle of bearings, in order to clarify the building layout principle of Gyeongbokgung Palace. Gyeongbokgung Palace shows the typical geographical conditions that meet the principle of Baesan Imsu (mountain in the back and water in the front) which takes Baegaksan Mountain as the main mountain and the overall layout of the buildings that meet the principle of 'Jeonchak Hugwan (narrow in the front and broad toward inside)' by using the natural topography that meets the principle of 'Jeonjeo Hugo (low in the front and higher toward back).' It is estimated that this layout and arrangement must have been led by geomantic principle of bearings. The analysis of the building layout plan of Gyeongbokgung Palace in the late Joseon Dynasty Period suggests the application of two methods: one is to divide central area from Gwanghwamun Gate to Geoncheongung Hall into eight layers and the other is to apply the bearings of the Eight Trigrams based on the building that becomes the center. As a result, the gate, main hall, and kitchen of all major buildings where the royal family lived are located in the auspicious bearings according to the geomantic principle of bearings while the spaces where people other than the royal family such as those who served the royal family and the officials operated in the palace or the hall that enshrines the ancestors such as Taewonjeong Hall are located in the ominous bearings. Therefore, the buildings of Gyeongbokgung Palace are arranged based on the geomantic principle of bearings.

용존성 방류수 유기물질이 비스페놀 A의 흡착 및 에스트로겐 활성에 미치는 영향 (Effect of Dissolved Effluent Organic Matter on Adsorption and Estrogenic Activity of Bisphenol A)

  • 유지수;나주림;정진호
    • Ecology and Resilient Infrastructure
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    • 제6권2호
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    • pp.128-135
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    • 2019
  • 본 연구는 하수종말처리장의 용존성 방류수 유기물질이 비스페놀 A (BPA)의 흡착과 에스트로겐 활성에 미치는 영향을 조사하였다. 특이적 자외선 흡수 (SUVA)와 형광 지수 (FI) 분석 결과, 방류수 유기물질은 참조물질로 사용한 스와니강 자연 유기물질과는 달리 미생물 기원의 비휴믹성 유기물질 특성을 나타내었다. Langmuir와 Freundlich 모델 모두 방류수 및 자연 유기물질에 대한 BPA의 흡착을 잘 설명하였다. 방류수 유기물질은 자연 유기물질 보다 더 높은 BPA 흡착능을 보여주었고, 이에 따라 에스트로겐 활성 역시 더 많이 감소시켰다. 이러한 결과들은 유기물질의 기원에 따라 BPA 흡착능과 에스트로겐 활성 저감이 크게 영향을 받는 다는 것을 제시한다.

Preliminary numerical study on hydrogen distribution characteristics in the process that flow regime transits from jet to buoyancy plume in time and space

  • Wang, Di;Tong, Lili;Liu, Luguo;Cao, Xuewu;Zou, Zhiqiang;Wu, Lingjun;Jiang, Xiaowei
    • Nuclear Engineering and Technology
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    • 제51권6호
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    • pp.1514-1524
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    • 2019
  • Hydrogen-steam gas mixture may be injected into containment with flow regime varying both spatially and transiently due to wall effect and pressure difference between primary loop and containment in severe accidents induced by loss of coolant accident. Preliminary CFD analysis is conducted to gain information about the helium flow regime transition process from jet to buoyancy plume for forthcoming experimental study. Physical models of impinging jet and wall condensation are validated using separated effect experimental data, firstly. Then helium transportation is analyzed with the effect of jet momentum, buoyancy and wall cooling discussed. Result shows that helium distribution is totally dominated by impinging jet in the beginning, high concentration appears near gas source and wall where jet momentum is strong. With the jet weakening, stable light gas layer without recirculating eddy is established by buoyancy. Transient reversed helium distribution appears due to natural convection resulted from wall cooling, which delays the stratification. It is necessary to concern about hydrogen accumulation in lower space under the containment external cooling strategy. From the perspective of experiment design, measurement point should be set at the height of connecting pipe and near the wall for stratification stability criterion and impinging jet modelling validation.

지역 농특산물의 베타카로틴 함량 조사 (A Study on Contents of Beta-Carotene in Local Agricultural Products)

  • 엄현주;강혜정;윤향식;권누리;김영호;홍성택;박진주;이준수
    • 한국식품영양학회지
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    • 제32권4호
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    • pp.335-341
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    • 2019
  • Beta-carotene is the most prominent member of the group of carotenoids, natural colorants that occur in the human diet. Beta-carotene is also an effective source of vitamin A in both conventional foods and vitamin supplements, and it's generally safe. In this study, we explored the beta-carotene contents in agricultural products widely and specifically grown in Korea. The beta-carotene contents were ranging from 223 to $27,908{\mu}g/100g$ in leaves, and 0 to $7,588{\mu}g/100g$ in vegetables. In leaves and vegetables, the amount of beta-carotene was the highest in green tea powder ($27,908{\mu}g/100g$), followed by pepper ($7,588{\mu}g/100g$). In fruits, the beta-carotene content was found to range from $0{\mu}g/1,011g$ to maximum of $293.66{\mu}g/100g$(plumcot). However, there beta-carotene was not detected in strawberry. In the case of cereals and specialty crops, the beta-carotene contents were $326{\mu}g/100g$ for non-glutinous rice, $313{\mu}g/100g$ for glutinous rice, $57{\mu}g/100g$ for amaranth and $15{\mu}g/100g$ for pine nut, respectively. However, the beta-carotene content was not detected in other samples. This study revealed the presence of beta-carotene content in agricultural products specifically grown in Korea for nutritional information and food composition database.

바이오매스 유래 플랫폼 케미컬들에 대한 효과적인 합성 방법들 (Efficient Synthetic Routes of Biomass-derived Platform Chemicals)

  • 이르샤드 모비나;이성우;최은주;김정원
    • 공업화학
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    • 제30권3호
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    • pp.280-289
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    • 2019
  • 5-Hydroxymethylfurfural (HMF) 및 그 유도체들인 2,5-furandicarboxylic acid (FDCA)와 2,5-diformylfuran (DFF)는 넓은 응용 범위와 중요한 화학 물질 생산을 위한 좋은 대체 자원으로 인해 "잠자는 거인"으로 인식되고 있다. 본 미니-리뷰 논문은 과거부터 최근까지 이러한 바이오매스 유래 케미컬 플랫폼들에 대한 합성, 전환과 적용에 관해 간략히 소개한다. 많은 과학적 노력들이 자연 환경과 새로운 미래 세대를 보호하기 위해서 재생 가능한 재료들의 최대한 활용을 위한 자연친화적-적용가능한 방법들을 찾기 위한 노력이 지속적으로 행해지고 있다. 최선의 해결책 중 하나는 자연바이오매스로부터 플랫폼 케미컬을 개발하고 활용하는 것이다.

In-vitro meat: a promising solution for sustainability of meat sector

  • Kumar, Pavan;Sharma, Neelesh;Sharma, Shubham;Mehta, Nitin;Verma, Akhilesh Kumar;Chemmalar, S;Sazili, Awis Qurni
    • Journal of Animal Science and Technology
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    • 제63권4호
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    • pp.693-724
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    • 2021
  • The in-vitro meat is a novel concept in food biotechnology comprising field of tissue engineering and cellular agriculture. It involves production of edible biomass by in-vitro culture of stem cells harvested from the muscle of live animals by self-organizing or scaffolding methodology. It is considered as efficient, environmental friendly, better ensuring public safety and nutritional security, as well as ethical way of producing meat. Source of stem cells, media ingredients, supply of large size bioreactors, skilled manpower, sanitary requirements, production of products with similar sensory and textural attributes as of conventional meat, consumer acceptance, and proper set up of regulatory framework are challenges faced in commercialization and consumer acceptance of in-vitro meat. To realize any perceivable change in various socio-economic and environmental spheres, the technology should be commercialized and should be cost-effective as conventional meat and widely accepted among consumers. The new challenges of increasing demand of meat with the increasing population could be fulfill by the establishment of in-vitro meat production at large scale and its popularization. The adoption of in-vitro meat production at an industrial scale will lead to self-sufficiency in the developed world.