• Title/Summary/Keyword: LEL

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A Study on Estimation of Lower Explosive Limits of Alcohol Compounds (알코올화합물의 폭발하한계 추산에 관한 연구)

  • Dong-Myeong Ha;Yong-Chan Choi;Haejin Oh;Su-kyung Lee
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2002.11a
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    • pp.291-296
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    • 2002
  • Flammable compounds are indispensible in domestic as well as in industrial fields as fuel, solvent and raw materials. The fire and explosion properties necessary for safe storage, transport, process design and operation of handling flammable substances are lower explosive limits(LEL), upper explosive limits(UEL), flash point, fire point, AIT(auto ignition temperature), MIE(minimum ignition energy), MOC(minimum oxygen concentration) and heats of combustion.

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Investigation of Combustible Characteristics for Risk Assessment of Benzene (벤젠의 위험성 평가를 위한 연소 특성치 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.24 no.5
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    • pp.28-33
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    • 2009
  • The thermochemical parameters for safe handling, storage, transport, operation and process design of flammable substances are explosion limit, flash point, autoignition temperatures(AITs), minimum oxygen concentration(MOC), heat of combustion etc.. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of benzene, lower explosion limit(LEL) at $25^{\circ}C$, the temperature dependence of the explosion limits and flash point were investigated. And the AITs for benzene were experimented. By using the literatures data, the lower and upper explosion limits of benzene recommended 1.3 vol% and 8.0 vol%, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for benzene, and the experimental AIT of benzene was $583^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of benzene is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

Linear versus Non-linear Interference Cancellation

  • Buehrer, R.Michael;Nicoloso, Steven P.;Gollamudi, Sridhar
    • Journal of Communications and Networks
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    • v.1 no.2
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    • pp.118-133
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    • 1999
  • In this paper we compare linear and non-linear inter-ference cancellation for systems employing code division multi-ple access (CDMA) techniques. Specifically, we examine linear and non-linear parallel interference cancellation(also called multi-stage cancellation) in relationship to other multiuser detection al-gorithms. We show the explicit relationship between parallel inter-ference cancellation and the decorrelator (or direct matrix inver-sion). This comparison gives insight into the performance of paral-lel interference cancellation (PIC) and leads to vetter approaches. We also show that non-linear PIC approaches with explicit chan-nel setimation can provide performance improvement over linear PIC, especially when using soft non-linear symbol estimates. The application of interference cancellation to non-linear modulation techniques is also presented along with a discussion on minimum mean-squared error(MMSE) symbol estimation techniques. These are shown to further improve the performance of parallel cancella-tion.

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Prediction of Explosion Limits of Ethers by Using Heats of Combustion and Stoichiometric Coefficients (연소열과 화학양론계수를 이용한 에테르류의 폭발한계의 예측)

  • Ha, Dong-Myeong
    • Journal of the Korean Institute of Gas
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    • v.15 no.4
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    • pp.44-50
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    • 2011
  • Explosion limit is one of the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, the lower explosion limit(LEL) and upper explosion limit(UEL) of ethers were predicted by using the heat of combustion and stoichiometric coefficients. The values calculated by the proposed equations agreed with literature data within a few percent. From the given results, using the proposed methodology, it is possible to predict the explosion limits of the other flammable ethers.

Characteristics of Acetaldehyde Decomposition over Heat Treated Cobalt Phthalocyanine Catalysts (열처리 조건에 따른 코발트 프탈로시아닌 촉매상에서 아세트알데히드 분해 특성)

  • 서성규;윤형선;김대중
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.489-490
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    • 2003
  • 아세트알데히드는 석유화학관련시설에서 많이 배출되는 것으로 알려져 있으며, 환경부 고시(제2001-36호)에 이를 포함한 37개 VOC 규제제품 및 물질로 명시되어 있다. 또한, 현재의 8개 악취물질에도 포함되어 있어 강력히 규제하고 있는 물질이다. 아세트알데히드의 주요 특성으로서 최소감지농도는 0.21ppm, LEL(Lower Explosive Limit)은 4%로 반응성이 매우 크며, 액상 및 증기상에서 가연성이 매우 큰 물질이다. 이러한 물질을 처리하기 위해 직접연소법과 촉매연소법을 이용하여 처리하고 있으나, 직접연소법을 이용하는 소각로의 경우 산업폐기물을 소각하는 과정에서 아세트알데히드가 배출되고 있어 아세트알데히드의 주 배출원 이며 고온처리로 인한 비용부담의 단점이 있다. (중략)

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Differentiation of Glycan Diversity with Serial Affinity Column Set (SACS)

  • Shin, Jihoon;Cho, Wonryeon
    • Mass Spectrometry Letters
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    • v.7 no.3
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    • pp.74-78
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    • 2016
  • Targeted glycoproteomics is an effective way to discover disease-associated glycoproteins in proteomics and serial affinity chromatography (SAC) using lectin and glycan-targeting antibodies shows glycan diversity on the captured glycoproteins. This study suggests a way to determine glycan heterogeneity and structural analysis on the post-translationally modified proteins through serial affinity column set (SACS) using four Lycopersicon esculentum lectin (LEL) columns. The great advantage of this method is that it differentiates between glycoproteins on the basis of their binding affinity. Through this study, some proteins were identified to have glycoforms with different affinity on a single glycoprotein. It will be particularly useful in determining biomarkers in which the disease-specific feature is a unique glycan, or a group of glycans.

A Study on Explosive Limits of Flammable Materials - Prediction of Explosive Properties and Temperature Dependence of Explosive Limits for n-Alcohols - (가연성물질의 폭발한계에 관한 연구 -알코올화합물의 폭발특성치 및 폭발한계의 온도의존성 예측-)

  • 하동명
    • Journal of the Korean Society of Safety
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    • v.14 no.1
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    • pp.93-100
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    • 1999
  • By using literature data, the empirical equations have been derived which describe the interrelationships of explosion and other related properties of n-alcohols. The properties which have been correlated data are : lower and upper explosive limits, heats of combustion, carbon numbers. Also, the new equation for predicting the temperature dependence of lower explosive limits(LEL) of n-alcohols on the basis of explosive limits, heats of combustion, flame propagation theory and mathematical method is proposed. The values calculated by the proposed equations were a good agreement with literature data within a few percent. From a given explosive properties. by using the proposed equations, it is possible to predict the other properties. It is hoped eventually that this method will permit the estimation of the explosive properties of alcohol with improved accuracy and the broader application for other compounds.

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Interrelationships of Fire and Explosion Properties for Chlorinated Hydrocarbons (염화탄화수소의 화재 및 폭발 특성치 간의 상관관계)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.17 no.4
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    • pp.126-132
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    • 2002
  • By using the reference data, the empirical equations which describe the interrelationships of explosion properties and physical properties of n-chlorinated hydrocarbons have been derived. The properties which have been correlated are the lower and upper explosive limits, the stoichiometric coefficients, the heats of combustion, the carbon numbers. Also, the new equations using the mathematical and statistical methods for predicting the temperature dependence of lower explosive limits(LEL) of chlorinated hydrocarbons on the basis of the literature data are proposed. The fire and explosion properties calculated by the proposed equations in this research were a good agrement with literature data within a few A.A.P.E.(Average Absolute Percent Error) and A.A.D.(Average Absolute Deviation.) From a given explosive properties, by using the proposed equations, it is possible to predict to the fire and explosion characteristics for the other chlorinated hydrocarbons.

Prediction of Temperature Dependence of Lower Explosive Limits for Paraffinic Hydrocarbons (파라핀족탄화수소의 폭발하한계의 온도의존성 예측)

  • 하동명
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.71-77
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    • 2000
  • The aim of this study is to investigate the temperature dependence of the lower explosive limit(LEL) at elevated temperature. The temperature dependence of the lower explosive limit is one of the significant indices of flammability and combustibility. By using the literature data, the new equations for predicting the temperature dependence of the lower explosive limits for paraffinic hydrocarbons are proposed. The values calculated by the proposed equations were a good agreement with the literature data. It is hoped eventually that this proposed equations will support the use of the prediction for the lower explosive limit and the flash points of the flammable mixtures.

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Prediction of Explosion Limits of Organic Halogenated Hydrocarbons by Using Heat of Combustions (연소열을 이용한 유기할로겐화탄화수소류의 폭발한계의 예측)

  • Ha, Dong-Myeong
    • Fire Science and Engineering
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    • v.26 no.4
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    • pp.63-69
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    • 2012
  • Explosion limit is one of the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, the lower explosion limit (LEL) and upper explosion limit (UEL) of organic halogenated hydrocarbons were predicted by using the heat of combustion and chemical stoichiometric coefficients. The calculated explosion limits by the proposed equations agreed with literature data within a few percent. From the given results, using the proposed methodology, it is possible to predict the explosion limits of the other organic halogenated hydrocarbons.