• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.69-74
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• 2013

The study was conducted experimentally on characteristic of thermal decomposition and minimum ignition temperature of magnesium dusts. For this purpose, three different Mg dusts of mean diameter (38, 142, $567{\mu}m$) were used. Experimental investigations were conducted by using TGA(Thermo gravimetric analysis) and MIT(Minimum Ignition Temperature) apparatus made in accordance with IEC 61241-2-1 standard. As the results, temperature of weight gain in Mg dust layers increased with increasing of heating rates in air and, under the same heating rate condition, minimum ignition temperature increased with particle size. Also the MIT of suspended Mg dust clouds tended to increase with increasing of mean diameter.

• Fire Science and Engineering
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• v.24 no.2
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• pp.172-177
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• 2010

The values of the AIT (autoignition temperature) for fire and explosion protection are normally the lowest reported. The MAITB (Minimum Autoignition Temperature Behavior) of flammable liquid mixture is exhibited when the AITs of mixture is below the AIT of the individual components. The MAITB is an interesting experimental features, which can be significant from the perspective of industrial fire safety. In this study, the AITs of toluene + iso-propanol(IPA) and p-xylene + n-butanol systems were measured using ASTM E659-78 apparatus. The AITs of toluene, iso-propanol (IPA), pxylene and n-butanol which constituted two binary systems were $547^{\circ}C,\;463^{\circ}C,\;557^{\circ}C$ and $340^{\circ}C$ respectively. The toluene + iso-propanol(IPA) system is exhibited MAITB at 0.3 mole fraction of toluene, and its minimum autoignition temperature was $460^{\circ}C$.

• Solar Energy
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• v.6 no.1
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• pp.3-11
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• 1986

Minimum fludizing velocities and voidages were investigated for closely sized sand and magnesia particles with mean diameters in the range of $297-841\;{\mu}m$ over the temperature between 15 and $1.000^{\circ}C$. Boundaries between changing behaviour at $Re_{mf}=14$ and Ar=17,000 were observed. In beds of fine particles in Geldart's group "B", the minimum fluidizing velocity ($U_{mf}$) decreased as temperature increased, but not as much as expected on account of the gas viscosity increase, furthermore the increase in the minimum fluidizing voidage (${\in}_{mf}$). With larger particles in group "D", $U_{mf}$ increased, first, with temperature increase because of reduced gas density, and depending on the particle size, $U_{mf}$ reduced as flow conditions moved from turbulent to laminar. Among the correlations predicting $U_{mf}$, Ergun equation agreed best with the experimental data providing that the change in ${\in}_{mf}$ according to temperature is allowed for.

• Journal of the Korea Safety Management & Science
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• v.11 no.1
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• pp.43-49
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• 2009

This study set three kinds of situation and observed the various states such as carbonization by experimenting damages by fire of electric iron. The results of this study are as follows: The fire did not occurred when the unpowered iron over mattress and cotton shirts was com busted completely by external flame because the temperature of surface of soleplate and mattress did not reach the minimum ignition energy and when the powered electric iron over mattress and cotton shirts was left for an hour with its temperature dial set to high because the temperature of combustibles did not reach the minimum ignition energy. The fire occurred when the electric iron in which the outer box, bi-metal switch, and temperature fuse were removed over mattress and cotton shirts was powered by through heater terminal, and then the electric iron, mattress, and cotton shirts were combusted by the fallen combustibles because the temperature of combustibles reached to the minimum ignition energy with the help of active transfer of heat.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.70-75
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• 2008

The values of the AIT(Autoignition temperature) for fire and explosion protection are normally the lowest reported. The minimum autoignition temperature behavior(MAITB) of flammable liquid mixtures is exhibited when the AIT of mixture is below the AIT of the individual components. The MAITB is an interesting experimental features, which can be significant from the perspective of industrial safety. In this study, the AITs of m-xylene+n-butyric acid and ethylbenzene+n-butanol systems were measured using ASTM E659-78 apparatus. The AITs of m-xylene, n-butyric acid, ethylbenzene and n-butanol which constituted two binary systems were $587^{\circ}C$, $510^{\circ}C$, $475^{\circ}C$ and $340^{\circ}C$ respectively. The m-xylene+n-butyric acid system is exhibited MAITB at 0.3 mole fraction of m-xylene, and its minimum autoignition temperature was $460^{\circ}C$.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.1
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• pp.77-96
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• 2017

This study was carried out to clarify the climatic factors of the freezing injury for the judgement on the adaptation areas of evergreen broad-leaved trees. We surveyed and analyzed the climatic factors of the freezing injury to Machilus thunbergii Siebold & Zucc. on the streets with the analyzation of planting grounds, soil conditions and the surrounding buildings. This study showed that only the minimum air temperature factor out of the other climate elements, which were the annual precipitation; the average annual temperature; the average monthly temperature of january; the average monthly minimum temperature of January; the average temperature of the coldest month; the warmth index and the coldness index, was matched up with the previous theories and reports on the freezing damages on the evergreen broad leaved trees and Machilus thunbergii Siebold & Zucc. The freezing injury of Machilus thunbergii Siebold & Zucc was occurred when the mean minimum temperature of the coldest month(TMC) in winter season fell down below $-4.1^{\circ}C$ and the temperature fell down below $-9.2^{\circ}C$. The freezing damage on Machilus thunbergii Siebold & Zucc surrounded by high buildings were less than those surrounded by low buildings or at non buildings.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.759-768
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• 2019

This study was conducted to estimate the mean annual extreme minimum temperature raster and predict the potential distribution of the invasive plant, Ipomoea triloba, on the Korean peninsula. We collected annual extreme minimum temperature and mean coldest month minimum temperature data from 129 weather stations on the Korean peninsula from 1990-2019 and used this data to create a linear regression model. The min temperature of the coldest month raster from Worldclim V2 were used to estimate a 30 second spatial resolution, mean annual extreme minimum temperature raster of the Korean peninsula using a regression model. We created three climatic rasters of the Korean peninsula for use with the Proto3 species distribution model and input the estimated mean annual extreme minimum temperature raster, a Köppen-Geiger climate class raster from Beck et al. (2018), and we also used the mean annual precipitation from Worldclim V2. The potential distribution of I. triloba was estimated using the Proto3 model with 117 occurrence points. As a result, the estimated area for a potential distribution of I. triloba was found to be 50.7% (111,969 ㎢) of the Korean peninsula.

• Atmosphere
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• v.24 no.1
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• pp.29-38
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• 2014

A characteristic of snowfall and minimum temperature variability in South Korea with respect to the variability of Arctic Oscillation (AO) was investigated. The climatic snowfall regions of South Korea based on daily new fresh snowfall data of 59 Korea Meteorological Administration (KMA) stations data corresponding to the sign of AO index during December to February 1979~2011 were classified. Especially, the differences between snowfalls of eastern regions and that of western regions in South Korea were seen by each mean 1000hPa geopotential height fields, which is one of physical structure, for the selected cases over the East Asia including the Korean Peninsula. Daily minimum temperature variability of 59 KMA station data and daily AO index during the same period were investigated using Cyclo-stationary empirical orthogonal function (CSEOF) analysis. The first CSEOF of wintertime daily AO index and that of minimum temperature of 59 KMA stations explain 33% and 66% of total variability, respectively. Correlation between principal component time series corresponding to the first CSEOF of AO index and that of temperature at the period of 1990s is over about -0.7 when that of AO index leads about 40 days.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.137-140
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• 2004

The minimum ignition temperature at which the dust cloud can spontaneously ignite is considered to be very important in industries to prevent explosion occurring in hot surfaces. This paper has dealt with the experimental study of the determination of minimum ignition temperature of Hydroxy Propyl Methyl Cellulose (HPMC) dust cloud. We have used the Godbert-Greenwald Furnace Apparatus to determine the ignition temperature and limiting oxyten concentration for dust could. The experimental determinations on the minimum ignition temperature were carried out with various particle size with nominal diameters 45, 75 and 106${\mu}m$. The limiting oxygen concentration of dust cloud was determinated for the smaller size(45${\mu}m$) HPMC. Minimum ignition temperature of dust cloud was at 364$^{\circ}C$ for the concentration of 2.5g/L in the air and became higher with the increasing of nitrogen concentration. It was also found that the ignition didn't occur when the oxygen concentration was below 10%, and limiting oxygen concentration is at 11%.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.937-942
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• 2008

In this paper, new methodology is proposed to estimate the cooling load using design parameters of building and predicted weather data. Only two parameters such as maximum and minimum temperature are necessary to obtain hourly distribution of cooling load for the next day. The maximum and minimum temperature that are used for input parameters can be obtained from forecasted weather data. Benchmarking building(research building) is selected to validate the performance of the proposed method, and the estimated cooling loads in hourly bases are calculated and compared with the measured data for benchmarking building. The estimated results show fairly good agreement with the measured data for benchmarking building.