• 제목/요약/키워드: Reference materials

검색결과 1,951건 처리시간 0.034초

가구소재의 화재전파해석을 위한 열해리 물성 평가 (Estimation of Pyrolysis Properties for Fire Propagation Analysis of Furniture Materials)

  • 김성찬
    • 한국화재소방학회논문지
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    • 제27권4호
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    • pp.41-46
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    • 2013
  • 본 연구는 가구류를 구성하는 주요 재료의 열적조건에 따른 반응특성과 화염전파해석에 필요한 열해리 물성을 제공하기 위해 열중량분석을 수행하였다. 실험대상 시편은 가구류에 널리 적용되는 MDF 판재와 코팅재, 합성피혁과 쿠션재 등이며 가열율 $10^{\circ}C/min$, 최대 온도 $600^{\circ}C$까지 실험을 수행하였다. 실험결과 MDF 소재의 경우 $324^{\circ}C$에서 피크 반응을 나타냈었으며 MDF 코팅재의 경우 초기 피크반응온도가 $270{\sim}280^{\circ}C$로 감소하였다. 합성피혁과 폼 소재의 경우 재료를 구성하는 폴리머의 종류에 따라 기준온도와 기준 반응율이 차이를 보였으나 기준온도는 $270^{\circ}C$$420^{\circ}C$ 정도로 비교적 유사한 경향을 나타냈다. Lyon 등이 제시한 방법에 의해 반응상수와 활성화 에너지를 산정하기 위해 시편의 기준 온도와 기준 반응율을 제시하였으며 이러한 기초 물성연구를 통해 화염전파특성을 이해함과 동시에 화재해석의 신뢰성을 향상시키는데 기여하고자 한다.

iRINGTools를 활용한 ISO 15926 기반 기자재 참조 데이터 서버의 구축과 활용 (Construction of an ISO 15926-based Reference Data Server Using iRINGTools and Its Application)

  • 김봉철;박상진;권순조;변수진;문두환;한순흥
    • 한국CDE학회논문집
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    • 제22권2호
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    • pp.150-161
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    • 2017
  • Effective data exchange among the diverse stakeholders participating in a process plant project is an important issue. ISO 15926 is an international standard to support sharing and integrating of process plant data. iRINGTools is an ISO 15926-based tool used to exchange plant data. To exchange plant data using iRINGTools, the mapping between the data model of a commercial system and ISO 15926 should be preceded. To accomplish this, types and properties of equipment and materials used for plant design should be predefined and these data should be represented as user-defined reference data complying with ISO 15926. Besides, the user-defined reference data should be serviced by a reference data server such that iRINGTools searches reference data from the server and utilizes the data for the model mapping. In this paper, we present a method to construct a reference data server and use it for the model mapping in iRINGTools. The proposed method is verified through experiments of exchanging specifications data of equipment and materials using iRINGTools.

Effect of Initial (Reference) Welding Current for Adaptive Control and It's Optimization to Secure Proper Weld Properties in Resistance Spot Welding

  • Ashadudzzaman, Md.;Choi, Il-Dong;Kim, Jae-Won;Nam, Dae-Geun;Park, Yeong-Do
    • Journal of Welding and Joining
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    • 제33권6호
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    • pp.13-20
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    • 2015
  • Many automotive companies are endeavoring to improve the quality of resistance spot welding by updating body-in-white (BIW) production line with adaptive control spot welding system to compensate the process disturbances such as gap, electrode wear, oxidized surfaces, poor fit up and adhesive etc. Most of the commercial adaptive weld controllers require proper "Initial Welding Schedule" or "Reference weld" to achieve compensation in welding parameters during real time welding. In this study, the compensation of a commercial adaptive weld controller had been observed and analyzed thoroughly for various process disturbances to find optimal initial welding schedule. It was observed that 90 percent of the expulsion current in constant current control as reference welding schedule conferred the maximum button diameter in adaptive control welding. Finally, effects of each disturbance in combined field disturbances system with adaptive control had also been confirmed with the design of experiment (DOE) by minitab(R)16 for combined disturbances situation and suitability of optimum initial weld current had also established with real body part validation test.

Evaluation of reference genes for RT-qPCR study in abalone Haliotis discus hannai during heavy metal overload stress

  • Lee, Sang Yoon;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • 제19권4호
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    • pp.21.1-21.11
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    • 2016
  • Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

Temperature Calibration of a Specimen-heating Holder for Transmission Electron Microscopy

  • Kim, Tae-Hoon;Bae, Jee-Hwan;Lee, Jae-Wook;Shin, Keesam;Lee, Joon-Hwan;Kim, Mi-Yang;Yang, Cheol-Woong
    • Applied Microscopy
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    • 제45권2호
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    • pp.95-100
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    • 2015
  • The in-situ heating transmission electron microscopy experiment allows us to observe the time- and temperature-dependent dynamic processes in nanoscale materials by examining the same specimen. The temperature, which is a major experimental parameter, must be measured accurately during in-situ heating experiments. Therefore, calibrating the thermocouple readout of the heating holder prior to the experiment is essential. The calibration can be performed using reference materials whose phase-transformation (melting, oxidation, reduction, etc.) temperatures are well-established. In this study, the calibration experiment was performed with four reference materials, i.e., pure Sn, Al-95 wt%Zn eutectic alloy, NiO/carbon nanotube composite, and pure Al, and the calibration curve and formula were obtained. The thermocouple readout of the holder used in this study provided a reliable temperature value with a relative error of <4%.

A Source-Related Approach for Discussion on Using Radionuclide-Contaminated Materials in Post-accident Rehabilitation

  • Kazuji Miwa;Takeshi Iimoto
    • Journal of Radiation Protection and Research
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    • 제48권2호
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    • pp.68-76
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    • 2023
  • Background: In the process of discussion on the possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, a strategy for the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. Materials and Methods: The radiological protection criteria that are likely to be applied to the source-related approach based on the International Commission on Radiological Protection recommendations and the International Atomic Energy Agency safety standards are summarized. We proposed five interpretations of radiation protection to contribute to the promotion of discussion on the possibility of using a part of low-level-radionuclide-contaminated soil and debris in the post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in the post-accident rehabilitation when the sources are handled in a planned activity." The former idea is subdivided into three based on the definition of the source, which is managed by the reference level, and the latter idea is divided into two depending on whether or not additional dose from using contaminated materials is deemed acceptable. Results and Discussion: To confirm the applicability of the five interpretations presented, we suggested the concrete values of protection criteria via two feasible cases. In this case study, we proposed radiation protection by the dose constraint based on the Interpretation IV and chose 1 mSv/yr for the public and 20 mSv/yr for workers dealing with radionuclide-contaminated materials. Conclusion: We concretely and systematically demonstrated how the concept of radiation protection can be applied to the process of discussion on the possibility of using radionuclide-contaminated materials within the framework of an international system of protection. This study's findings can provide necessary information to discuss the possibility of using radionuclide-contaminated materials as an alternative option for recovery and reconstruction after a radiation disaster from the viewpoint of radiation protection.

미국과 한국의 참고봉사 교육의 비교분석 (A comparative analysis of reference education between the United States and Korea)

  • 정춘화
    • 한국도서관정보학회지
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    • 제23권
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    • pp.253-284
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    • 1995
  • The purpose of this paper is to analyse the current status of reference education and to suggest directions for reference education in America and in Korea. For this purpose, the historical developments of reference services, and the names, problems and changes of reference courses are studied. The findings of the study can be summarized as follows; 1. The names of reference courses are various. In America, On-Line Services or Information Services are used in general, but in Korea, Reference Services are widely used. 2. In America, some library schools have only subject literature courses including business, law, music, etc. instead of basic reference courses. 3. Only one reference course is given by most schools in America and in Korea. However, a few schools which have no graduate courses provide two reference courses in Korea. 4. Analysis of textbooks used in reference courses shows that Reference Research by Joon-Shik Park, Reference Services and Reference Sources by Ock-Soon Noh are used in general. In addition, Introduction to Reference Work by Katz is used. 5. Lecture methods are generally used in teaching reference courses, but reviews of reference materials in library, class presentation, and case study method are also used. It is desirable that role playing and pathfinders' used in U.S. are introduced to our schools. 6. Analysis of library user instruction courses in Korea shows that 7 of 11 universities have the courses,, only one university teaches library user instruction as a part of reference courses, 3 universities don't. 7. Analysis of opinions about the directions for reference education shows that changes of reference courses names, expansion of courses contents, emphasis on communication technique, changes of teaching methods, proper combination of theory vs. practice, an increase in electronic reference education and training of subject specialist are needed.

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동위원소 희석 HPLC/MS에 의한 혈청 내 urea의 정량 (Quantification of urea in serum by isotope dilution HPLC/MS)

  • 이화심;박상열
    • 분석과학
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    • 제18권4호
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    • pp.271-277
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    • 2005
  • 혈액 내 urea는 임상진단 시 신장 기능을 판단하는 중요한 표지물질로서 측정되고 있다. 단백질 등 질소화합물의 최종 대사물인 urea는 콩팥의 사구체에서 걸러져 소변으로 배출되는데, 사구체의 거르는 능력이 저하되면 결국 혈액 속의 urea 농도가 증가하게 되어 신장 기능의 정상여부를 판단할 수 있게 된다. 이러한 임상진단 결과의 신뢰성 향상을 위해서는 측정결과가 일차분석법으로 인증된 인증표준 물질과 소급성 고리를 유지해야 한다. 본 연구에서는 혈청 내 urea의 일차분석법으로서 $15^N_2$-urea를 내부 표준물질로 사용하는 동위원소희석 액체크로마토그라피-질량분석법 (ID-HPLC/MS)을 개발하였다. 이 방법은 측정원리상 고도의 정확성이 확보될 뿐 아니라 별도의 유도체화가 필요 없기 때문에 빠르고 편리하다. $C_{18}$-분리관에 0.1 mmol/L $NH_4Cl$ buffer를 이동상으로 사용하여 urea를 분리하였는데, 이 완충용액은 비교적 분자량이 작은 urea를 질량분석하는데 방해가 크지 않은 장점이 있다. HPLC와 질량분석기의 인터페이스로서 positive mode의 electrospray ionization (ESI)를 사용하여 높은 감도와 재현성을 성취하였다. 국제적으로 인정된 인증표준물질의 분석을 통해 최적화된 방법의 유효성을 확인하였으며, 국제비교시험에도 참여하여 좋은 결과를 얻었다. ISO guide에 따라 불확도를 계산하였으며, 확장 불확도는 95% 신뢰도에서 약 1.8%로 나타났다. 이 분석법은 표준연에서 개발 중인 혈청인증표준물질을 인증하는 일차기준측정절차로도 사용되고 있다.

모델기반 신경망 제어기를 이용한 열린 박스 구조물의 진동제어 (Active Vibration Control of a Opened Box Structure By a Model Reference Neuro-Controller)

  • 장승익;신윤덕;기창두
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1602-1607
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    • 2003
  • Vibration causes noise and sometimes makes structure unstable. Especially, due to the efforts of lightening, deformation of flexible structure is increased in its shape. Just a little disturbance can cause vibration and low damping ratio makes residual vibration last long time. This research is concerned with the model reference neuro-controller design for the vibration suppression of smart structures. By using a model reference neurocontroller, which is one of the algorithms of adaptive control, we performed an adaptive control of flexible cantilever plate and opened box structure with piezoelectric materials. The proposed adaptive vibration control algorithm, a model reference neuro-controller, was proved in its effectiveness by applying to an opened box structure. The model reference neuro-controller is implemented with DSP, and the real-time adaptive vibration control experiment results confirm that the model reference neuro-controller is reliable.

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표면분석용 인증표준물질의 개발 I : 표면조성분석용 합금박막 표준물질 (Development of certified reference material (CRM)s for surface analysis I : alloy thin film for surface compositional analysis)

  • 김경중;박용섭;문대원
    • 한국진공학회지
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    • 제8권3B호
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    • pp.276-282
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    • 1999
  • For the quantitative surface analysis of multicomponent materials, algorithms for the compensation of the matrix effect and surface compositional change by ion beam sputtering must be established and reference materials having certified compositions are necessary. These certified reference material (CRM)s are needed for the improvement of instrument performance, inter-laboratory comparison and quantitative surface analysis. Surface analysis group of KRISS developed alloy thin film CRMs by and ion beam sputter deposition system and in-situ surface analysis system to control the composition of alloy thin films The real compositions of the CRMs were certified by inductively coupled plasma-atomic emission spectroscopy (ICP-AES).

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