• 제목/요약/키워드: Flash method

검색결과 542건 처리시간 0.026초

2-프로판올과 톨루엔 혼합물질의 인화점 측정에 관한 연구 (Study on the Flash Point Determination of 2-Propanol-Toluene Mixtures)

  • 목연수;최재욱;김영일;최일곤;하동명
    • 한국안전학회지
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    • 제12권3호
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    • pp.114-119
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    • 1997
  • The lower flash points and upper flash points of 2-propanol and toluene mixtures were determined by air-blowing method instead of Tag-closed flash point tester. The relations between the flash points and the composition of the mixtures are as follows, $T_{F.L}=4.3182+6.0909X_1$ $T_{F.U}=39.3636-2.9091X_1$ As results, the experimental data and the estimated values from the relations are considerably agreed, and we could plotted the relative diagram between flash points and the explosive range.

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UNIFAC 그룹 기여 모델에 의한 n-Octnae+n-Decane 계와 n-Octane+n-Dodecane 계의 인화점 계산 (Flash Point Calculation for n-Octane+n-Decane and n-Octane+n-Dodecane by UNIFAC Group Contribution Model)

  • 하동명;이성진
    • 한국안전학회지
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    • 제30권4호
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    • pp.86-91
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    • 2015
  • The flash point is used to categorize inflammable liquids according to their relative flammability. Such a categorization is important for the safe handling, storage, and transportation of inflammable liquids. The flash point temperature of two binary liquid mixtures(n-octane+n-decane and n-octane+n-dodecane) has been measured for the entire concentration range using Seta-flash closed cup tester based on the ASTM D3278 method. The closed cup flash point temperature was estimated using the UNIFAC(Universal Functional Activity Coefficient) group contribution model. The experimentally derived flash point was also compared with the predicted flash point from the UNIFAC model. The UNIFAC model is able to estimate the flash point fairly well for n-octane+n-decane mixture and n-octane+n-dodecane mixture.

Determine the return period of flash floods by combining flash flood guidance and best fit distribution

  • Duong, Ngoc Tien;Kim, Jeong-Bae;Bae, Deg-Hyo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2020년도 학술발표회
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    • pp.362-362
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    • 2020
  • Flash flood is a dangerous weather phenomenon, affecting humans and the economy. The identification, forecast of the changing trend and its characteristics are increasingly concerned. In the world, there have many methods for determining the characteristics of flash floods, in which flash flood guidance (FFG) is a fast, effective and widely used method. The main source of flash floods is short-term rainfall. In this study, we used the data of cross-sectional measurement at the tributaries and the hourly rain data from the automatic rainfall measurement stations in the Geum river basin. Besides, we use a combination of the flash flood guidance and the best fit distribution function to estimate the repeatability of flash floods for head-water catchments in Geum river basin. In which, FFG determines the threshold of rainfall for flash floods. The study has determined the best hourly rainfall distribution function for the Geum river basin and estimated the maximum rainfall of 1hr according to the return periods.

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The Correlation of Lower Flash Point data with Activity Coefficient Models

  • Ha, Dong-Myeong;Lee, Sungjin
    • International Journal of Safety
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    • 제10권1호
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    • pp.5-9
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    • 2011
  • Two popular activity coefficient models, Wilson and NRTL equations have been used to correlate the published flash point data on the n-propanol + propionic acid and n-butanol + propionic acid systems through the optimization method. The results of these correlation were compared with the results calculated by Raoult's law. The optimization method were found to be better than those based on the Raoult's law. The optimization method based on the Wilson equation described the published data more effectively than was the case when the optimization method was based upon the NRTL equation.

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고집적화된 1TC SONOS 플래시 메모리에 관한 연구 (A Study on the High Integrated 1TC SONOS flash Memory)

  • 김주연;김병철;서광열
    • 한국전기전자재료학회논문지
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    • 제16권5호
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    • pp.372-377
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    • 2003
  • To realize a high integrated flash memory utilizing SONOS memory devices, the NOR type ITC(one Transistor Cell) SONOS flash arrays are fabricated and characterized. This SONOS flash arrays with the common source lines are designed and fabricated by conventional 0.35$\mu\textrm{m}$ CMOS process. The thickness of ONO for memory cells is tunnel oxide of 34${\AA}$, nitride of 73${\AA}$ and blocking oxide of 34${\AA}$ . To investigate operating characteristics, CHEI(Channel Hot Electron Injection) method and bit line method are selected as the program and 4he erase operation, respectively. The disturbance characteristics ,according to the program/erase/read cycling are also examined. The degradation characteristics are investigated and then the reliability of SONOS flash memory is guaranteed.

Filter Driver 와 NAND FLASH Memory를 이용한 HDD 장치의 성능 개선에 관한 연구 (A Study of HDD Performance Improvement through Filter Driver & NAND FLASH Memory)

  • 김우길;김영길
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2010년도 추계학술대회
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    • pp.58-61
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    • 2010
  • 본 논문에서는 I/O Filter Driver 와 NAND FLASH Memory의 적용을 통한 HDD 저장장치의 느린 I/O 성능을 개선하기 위한 방법에 대해 연구했다. 반도체 부품으로서 빠른 I/O 성능을 보이는 NANDFLASH Memory의 적용과 이를 구동시키기 위한 Filter Driver (Device Driver)를 적용했으며, 이를 통해 HDD 저장장치의 향상된 I/O성능을 분석하고 개선하는 방법을 제안한다.

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USB 플래시 드라이브를 이용한 DSP 펌웨어 업데이트 (DSP Firmware Update Using USB Flash Drive)

  • 김진순;최준영
    • 대한임베디드공학회논문지
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    • 제18권1호
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    • pp.25-30
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    • 2023
  • We propose a method to update DSP (Digital Signal Processor) firmware using USB (Universal Serial Bus) flash drives. The DSP automatically detects USB drives based on an interrupt when the USB drive is inserted into the USB port. The new firmware binary file is found in the mounted USB drive, and the destination address of DSP flash memory is identified for the firmware update writing by investigating the firmware file header. After the new firmware is written to the DSP flash memory, the DSP is reset and rebooted with the newly updated firmware. By employing TI's TMS320F28379D control card with USB ports, we conduct experiments and verify the normal operation of the implemented method.

클리브랜드 개방식 장치를 이용한 2성분계의 인화점 (Flash Points of the Binary Solutions Using Cleveland Open Cup Tester)

  • 하동명;이성진
    • 한국화재소방학회논문지
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    • 제25권1호
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    • pp.57-62
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    • 2011
  • 인화점은 공정안전을 평가할 때 산업공정에서 가연성 액체의 중요한 연소 특성 가운데 하나이다. 본 연구에서는 클리브랜드 개방식 장치를 사용하여 n-propanol + formic acid계와 acetic acid + propionic acid계의 인화점을 측정하였다. 실험값은 Raoult의 법칙과 최적화 기법에 의해 추산된 값과 비교하였다. 그 결과, 최적화 기법에 의한 추산값이 Raoult의 법칙에 의한 추산값 보다 실험값에 더욱 근접하였다.

Seta Flash 밀폐식 장치를 이용한 n-Propanol+n-Hexanol계와 n-Butanol+n-Hexanol계의 인화점 측정 (Flash Point Measurement of n-Propanol+n-Hexanol and n-Butanol+n-Hexanol Systems Using Seta Flash Closed Cup Tester)

  • 하동명;이성진
    • 한국안전학회지
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    • 제34권1호
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    • pp.34-39
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    • 2019
  • Flash point is the important indicator to determine fire and explosion hazards of liquid solutions. In this study, flash points of n-propanol+n-hexanol and n-butanol+n-hexanol systems were obtained by Seta flash tester. The methods based on UNIFAC equation and multiple regression analysis were used to calculate flash point. The calculated flash point was compared with the experimental flash point. Absolute average errors of flash points calculated by UNIFAC equation are $2.9^{\circ}C$ and $0.6^{\circ}C$ for n-propanol+n-hexanol and n-butanol+n-hexanol, respectively. Absolute average errors of flash points calculated by multiple regression analysis are $0.5^{\circ}C$ and $0.2^{\circ}C$ for n-propanol+ n-hexanol and n-butanol+n-hexanol, respectively. As can be seen from AAE, the values calculated by multiple regression analysis are noticed to be better than the values by the method based on UNIFAC eauation.

PROMETHEE와 Entropy 기법을 이용한 돌발홍수 위험도 평가 (Flash Flood Risk Assessment using PROMETHEE and Entropy Method)

  • 이정호;전환돈;박무종;정재학
    • 한국방재학회 논문집
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    • 제11권3호
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    • pp.151-156
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    • 2011
  • 과거 홍수 방재에 관한 노력의 대부분은 대하천을 중심으로 이루어져 왔다. 그러나 경제의 발전과 더불어 레져 활동 영역이 산지유역으로 확대되면서 돌발홍수로 인한 인명사고의 발생이 빈번해졌고 이로인한 추가적인 방재 활동이 요구되고 있다. 그러므로 돌발홍수로 인한 인명 및 재산의 피해를 감소시키기 위하여 본 연구에서는 다양한 지표들을 고려하여 산지유역에서의 돌발홍수 발생 위험도를 평가하기 위한 새로운 기법을 개발하였다. 고려된 다양한 지표들의 돌발홍수 발생에 대한 기여도를 평가하기 위하여 본 연구에서는 다기준의사결정 기법의 하나인 프로메티(Preference Ranking Organization METHod for Enrichment Evaluations, PROMETHEE)를 이용하였으며, 평가 지표들로는 지역특성, 강우특성 및 지형특성 등이 선정되었다. 또한 이상의 평가지표들에 대한 상대적 가중치 산정을 위하여 엔트로피(Entropy) 기법이 이용되었다. 엔트로피 기법과 프로메티를 이용한 돌발홍수 위험도 평가기법은 그 적용성을 검증하기 위하여 봉화군 유역에 적용되었으며, 적용 결과 봉화군 유역 내 17개 소유역에 대하여 그 상대적 위험도가 평가되었다. 또한 17개 소유역은 그 결과에 따라 각각 5개, 7개, 5개의 고 중 저위험군으로 분류되었다. 또한 적용결과의 추가적인 검증을 위하여 과거 돌발홍수 피해 사례를 조사한 결과 고위험군으로 평가된 지역들 중 한 곳에서 2008년 돌발홍수가 발생했었음을 확인하였다.