• 제목/요약/키워드: Standard Cells

검색결과 735건 처리시간 0.026초

무인 비행체용 연료전지 시스템 위험요소 분석을 통한 안전기준 개발 연구 (A Study on the Development of Safety Standard through the Risk Assessment for Fuel Cell System Applied to UAV)

  • 김태헌;최재욱;조인록;이정운
    • 한국수소및신에너지학회논문집
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    • 제35권1호
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    • pp.56-65
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    • 2024
  • Fuel cell powered unmanned aerial vehicles (UAV) are globally being developed for various application according to hydrogen roadmap. However, safety standards for hydrogen fuel cell for UAV have not been established. Therefore, in this study, we derive safety data based on risk assessment to develop safety standards for fuel cells for UAV. We use fault tree analysis method which is broadly used in hydrogen facilities as a risk assessment tool. We set hydrogen leaks and fires as top events and derived the basic events. Safety data for the basic events were derived by quoting overseas safety standards related to fuel cells. The safety data will be used for developing fuel cell inspection standard according to Act on Hydrogen Economy Promotion and Hydrogen Safety Management.

온도표준 기준 물질로의 개발을 위한 pivalic acid의 고순도 정제 (Purification of pivalic acid : its evaluation as a temperature standard reference material)

  • M. Karthikeyan;M. B. Koss;M. E. Glicksman;Kee-Kahb Koo
    • 한국결정성장학회지
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    • 제7권1호
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    • pp.151-162
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    • 1997
  • Pivalic acid를 진공 증류 및 zone refining을 이용 고순도로 정제하여 온도 표준 기준 물질로의 개발 가능성을 시험하였다. melting plateau curve를 이용하여 99.9997% 순도의 pivalic acid cell들의 삼중점을 측정한 결과 $35.956\pm 0.003^{\circ}C$를 얻을 수 있었다. 이상의 정밀도를 갖는 pivalic acid 삼중점 cell들은 고정밀도를 요구하지 않는 일반 thermistor 온도계류의 보정용으로 충분히 사용 가능한 것으로 판단된다.

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Secondary Circulating Tumor Cells (CTCs) but not Primary CTCs are Associated with the Clinico-Pathological Parameters in Chilean Patients With Colo-Rectal Cancer

  • Murray, Nigel P;Albarran, Vidal;Perez, Guillermo;Villalon, Ricardo;Ruiz, Amparo
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권11호
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    • pp.4745-4749
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    • 2015
  • Background: The aim of this study was to assess detection of circulating tumor cells (CTC) using anti-CEA pre and post surgery in Chilean patients with colo-rectal cancer. Materials and Methods: The presence of CTCs was evaluated in 80 colorectal cancer patients pre and post surgery using standard immunocytochemistry and the results were compared with findings for standard clinico-pathological parameters. Results: In patients presurgery CEA (+) CTCs were frequently found, with no relation to tumor size or nodal status. After surgery, the presence of CTCs was associated with such clinico-pathological parameters. The frequency of CTC detection in node positive patients did not change after surgery. In patients with metastasis there was also no change in the frequency of CTC detection, and clusters of 3 or more CTCs were evident. Conclusions: Secondary CTCs are associated with clinico-pathological parameters only after surgical removal of the primary tumor, and might be important in identifying patients at high risk of relapse. Primary CTCs detected before surgical removal are frequently found, are not associated with the clinico-pathological parameters and might have a role in cancer screening. These findings suggest the need for studies with a larger population of patients.

핵심국제비교용 물의 삼중점 셀 제작과 비교 실험 및 불확도 평가 (Construction and Comparison Measurement of Triple Point Water Cells for using Key Comparison and Evaluation of Uncertainty)

  • 강기훈;김용규;감기술
    • 센서학회지
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    • 제13권2호
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    • pp.114-120
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    • 2004
  • The $Comet{\acute{e}}$ Consultatif de $Thermom{\acute{e}}trie$ (CCT) under the Comete International des Poids et Measures (CIPM) has decided to perform the Key Comparison (KC) for triple point of water cells used as a reference fixed point of thermometry at the 21st meeting held at November 2001, and the Bureau International des Poids et Measures (BIPM) has been nominated as a KC coordinator. According to the KC protocol prepared by BIPM, KRISS performed the KC experiments and evaluate a uncertainty. The temperature difference between two reference cells for the Korea Research Institute of Standards and Science (KRISS) and a test cell for the transfer standard, which is moved to BIPM was 0.024 mK and the combined standard uncertainty evaluated 0.055 mK.

버들치, Rhynchocypris oxycephalus 초기 생식소 발달과 성분화에 관한 조직학적 연구 (Histological Study of the Early Gonadal Development and Sexual Differentiation in Rhynchocypris oxycephalus)

  • 박인석
    • 한국발생생물학회지:발생과생식
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    • 제2권1호
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    • pp.69-74
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    • 1998
  • 부화 후부터 평균전장 0.64 cm를 나타내는 부화 후 150일까지의 버들치, Rhynchocypris oxycephalus를 대상으로 초기생식소 발달과 성분화를 조사하였다. 시언생식세포는 평균전장 0.64cm 자어에서 뚜렷이 나타나\ulcorner. 평균전장 1.91 cm자어에서 시원생식세포는 복강으로돌출되었으며, 평균전장 2.29 cm 자어에서 시원생식세포는 감수분열 난모세포로 전환되었고, 난소로의 분화가 최초 확인되엇따. 평균전장 5.96 cm 자어에서 암컷 생식소는 점진적으로 발달하였으며 성숙단계로 접어드는 핵이동 난모세포를 보였다. 성분화 후 난모세포는 빠르게 증식하는 반면 정소는 평균전장 4.00cm 자어까지는 성장이 중지된 채 증가만 하는 휴지상태이었다. 평규전장 4.00cm 자어에서의 정모세포는 중간기에서 발달이 정지되었으며, 감수분열이 활발하였고, Sertoli-like cell과 정소관이 형성되었다. 본 연구 결과 버들치의 성본화 양상은 분화형 장웅이체 (differentiated gonochorism)인 것으로 나타났다.

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생체분리 면역세포를 이용한 면역기전 연구 (Study on the Immune Mechanism using Primary-cultured Immune Cells)

  • 김창환;박상진
    • 한국군사과학기술학회지
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    • 제16권3호
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    • pp.390-397
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    • 2013
  • Primary-cultured immune cells are widely used in research to elucidate the mechanism of inflammation including chemotaxis, production of reactive oxygen species, cytokine release and antigen presenting. Mice are one of the species of experimental animals commonly used for such studies. Immune cells can be isolated and cultured from various organs such as bone marrow, peritoneal cavity, lung, spleen. For elaborated experimental studies, immune cells should be elicited with inflammatory substances or proliferated in vitro with special media. This paper details methods of obtaining immune cells from various organs of mice and investigating immune mechanism using isolated immune cells. It contains standard protocols of isolating and culturing immune cells from bone marrow, peritoneal cavity and lymphoid organs. It also covers the methods of investigating immune mechanism such as ELISA, western blotting, confocal microscopy and ELISPOT assay. With the works in this study, we established the standardized isolation and analysis methods of primary-cultured immune cells.

Essential Guidelines for Manufacturing and Application of Organoids

  • Sun-Ju Ahn;Sungin Lee;Dayeon Kwon;Sejeong Oh;Chihye Park;Sooyeon Jeon;Jin Hee Lee;Tae Sung Kim;Il Ung Oh
    • International Journal of Stem Cells
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    • 제17권2호
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    • pp.102-112
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    • 2024
  • An organoid is a self-organized three-dimensional structure derived from stem cells that mimics the structure, cell composition, and functional characteristics of specific organs and tissues and is used for evaluating the safety and effectiveness of drugs and the toxicity of industrial chemicals. Organoid technology is a new methodology that could replace testing on animals testing and accelerate development of precision and regenerative medicine. However, large variations in production can occur between laboratories with low reproducibility of the production process and no internationally agreed standards for quality evaluation factors at endpoints. To overcome these barriers that hinder the regulatory acceptance and commercialization of organoids, Korea established the Organoid Standards Initiative in September 2023 with various stakeholders, including industry, academia, regulatory agencies, and standard development experts, through public and private partnerships. This developed general guidelines for organoid manufacturing and quality evaluation and for quality evaluation guidelines for organoid-specific manufacturing for the liver, intestines, and heart through extensive evidence analysis and consensus among experts. This report is based on the common standard guideline v1.0, which is a general organoid manufacturing and quality evaluation to promote the practical use of organoids. This guideline does not focus on specific organoids or specific contexts of use but provides guidance to organoid makers and users on materials, procedures, and essential quality assessment methods at end points that are essential for organoid production applicable at the current technology level.

전압표준용 RSFQ DAC의 전산모사 실험 (Simulation of RSFQ D/A converter to use as a voltage standard)

  • 추형곤;강준희
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.160-164
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    • 2000
  • Digital to analog converters based on the Josephson effect are promising for voltage standard, because they produce voltage steps with high precision and good stability. In this paper, we made a simulation study on RSFQ D/A converter. RSFQ D/A converter was composed of NDRO cells, T(toggle) flip-flops, D flip-flops, Splitters and Confluence Buffers. Confluence Buffer was used to reset the D/A converter. We also obtained operating margins of the important circuit values by simulational experiments.

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Stabile Fermentation of Citric Acid Using Immobilized Saccharomycopsis lipolytica

  • Kim, Eun-Ki;Ronnie S. Roberts
    • Journal of Microbiology and Biotechnology
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    • 제1권2호
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    • pp.130-135
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    • 1991
  • The effects of media composition on citric acid fermentation using surface immobilized Saccharomycopsis lipolytica were studied. The use of the standard medium for these organisms resulted in rapid decrease of citric acid production and a transformation of immobilized cell morphologies from a yeast-type to a mycelium-type. When the standard medium was enriched with vitamins, trace minerals, a growth factor and ammonium to form a Vigorous Stationary Phase (VSP) fermentation type medium, relatively stable citric acid production (10 mg/lㆍh) was obtained. Using the VSP type medium, the surface immobilized cells also retained their yeast-type form.

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