• Fire Science and Engineering
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• v.25 no.2
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• pp.120-125
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• 2011

For the safe handling of n-dodecane, the explosion limits were investigated and the lower flash points and AITs (autoignition temperatures) by ignition delay time were experimented. By using the literatures data, the lower and upper explosion limits of n-dodecanee recommended 0.6 Vol.% and 4.7 Vol.%, respectively. The lower flash points of n-dodecane by using closed-cup tester were experimented $77^{\circ}$ and $80^{\circ}C$. The lower flash points of n-dodecane by using open cup tester were experimented $84^{\circ}C$ and $87^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-dodecane. The experimental AIT of n-dodecane was $222^{\circ}C$.

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.75-81
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• 2011

For the safe handling of cyclohexane, the explosion limit at $25^{\circ}C$ and the temperature dependence of the explosion limits were investigated. Flash point and AIT(autoignition temperature) for cyclohexane were experimented. By using the literatures data, the lower and upper explosion limits of cyclohexane recommended 1.0 Vol% and 9.0 Vol%, respectively. Moreover lower flash points of cyclohexane recommended $-20^{\circ}C$. It was measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for cyclohexane, and the experimental AIT was $255^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of cyclohexane is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

• Fire Science and Engineering
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• v.15 no.3
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• pp.14-20
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• 2001

The flash points are one of the most important fundamental properties used to determine the potential for fire and explosion hazards of flammable substances. A classification of the flash points is important for the safe handling of flammable liquids which constitute the solvent mixtures. Basic to all flash points behavior are vapor pressure and explosive limits(lower explosive limit and upper explosive limit). The flash points of flammable solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this study, the reference values of lower flash points were compared with the calculated values by using Raoult's law and MRSM(modified response surface methodology) model. The lower flash points were in agreement with the predicted by Raoult's law and MRSM model. By means of this methodology, it is possible to evaluate reliability of experimental data of the flash points of the flammable mixtures.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.49-63
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• 2018

Purpose : The purpose of this study is investigating the changes of treatment plan and comparing skin dose with or without the skin flash. To investigate optimal applications of the skin flash, the changes of skin dose of each plans by various thicknesses of skin flash were measured and analyzed also. Methods and Material : Anthropomorphic phantom was scanned by CT for this study. The 2 fields hybrid IMRT and the 6 fields static IMRT were generated from the Eclipse (ver. 13.7.16, Varian, USA) RTP system. Additional plans were generated from each IMRT plans by changing skin flash thickness to 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm and 2.5 cm. MU and maximum doses were measured also. The treatment equipment was 6MV of VitalBeam (Varian Medical System, USA). Measuring device was a metal oxide semiconductor field-effect transistor(MOSFET). Measuring points of skin doses are upper (1), middle (2) and lower (3) positions from center of the left breast of the phantom. Other points of skin doses, artificially moved to medial and lateral sides by 0.5 cm, were also measured. Results : The reference value of 2F-hIMRT was 206.7 cGy at 1, 186.7 cGy at 2, and 222 cGy at 3, and reference values of 6F-sIMRT were measured at 192 cGy at 1, 213 cGy at 2, and 215 cGy at 3. In comparison with these reference values, the first measurement point in 2F-hIMRT was 261.3 cGy with a skin flash 2.0 cm and 2.5 cm, and the highest dose difference was 26.1 %diff. and 5.6 %diff, respectively. The third measurement point was 245.3 cGy and 10.5 %diff at the skin flash 2.5 cm. In the 6F-sIMRT, the highest dose difference was observed at 216.3 cGy and 12.7 %diff. when applying the skin flash 2.0 cm for the first measurement point and the dose difference was the largest at the application point of 2.0 cm, not the skin flash 2.5 cm for each measurement point. In cases of medial 0.5 cm shift points of 2F-hIMRT and 6F-sIMRT without skin flash, the measured value was -75.2 %diff. and -70.1 %diff. at 2F, At -14.8, -12.5, and -21.0 %diff. at the 1st, 2nd and 3rd measurement points, respectively. Generally, both treatment plans showed an increase in total MU, maximum dose and %diff as skin flash thickness increased, except for some results. The difference of skin dose using 0.5 cm thickness of skin flash was lowest lesser than 20 % in every conditions. Conclusion : Minimizing the thickness of skin flash by 0.5 cm is considered most ideal because it makes it possible to keep down MUs and lowering maximum doses. In addition, It was found that MUs, maximum doses and differences of skin doses did not increase infinitely as skin flash thickness increase by. If the error margin caused by PTV or other factors is lesser than 1.0 cm, It is considered that there will be many advantages in with the skin flash technique comparing without it.

• Fire Science and Engineering
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• v.26 no.2
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• pp.84-89
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• 2012

For the safe handling of n-nonanol, this study was investigated the explosion limits of n-nonanol in the reference data. The flash points and AITs (autoignition temperatures) by ignition delay time were experimented. As a results, the lower and upper explosion limits of n-nonanol recommended 0.8 Vol.% and 6.1 Vol.%, respectively. The lower flash points of n-nonanol by using closed-cup tester were experimented $94{\sim}97^{\circ}C$. The lower flash points of n-nonanol by using open cup tester were experimented $103{\sim}104^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-nonanol. The experimental AIT of n-nonanol was $270^{\circ}C$.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.70-76
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• 2013

For the safe handling of styrene, this study was investigated the explosion limits of styrene in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. As a results, the lower and upper explosion limits of styrene recommended 0.9 Vol.% and 8.0 Vol.%, respectively. The lower flash points of styrene by using closed-cup tester were experimented $29^{\circ}C{\sim}31^{\circ}C$. The lower flash points of styrene by using open cup tester were experimented $32^{\circ}C{\sim}36^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for styrene. The experimental AIT of styrene was $460^{\circ}C$.

• Fire Science and Engineering
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• v.25 no.4
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• pp.28-34
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• 2011

For the safe handling of cyclohexanone, the explosion limits at $25^{\circ}C$ were investigated. The lower flash points and AITs (auto-ignition temperatures) by ignition time delay for cyclohexanone were experimented. By using the literatures data, the lower and upper explosion limits of cyclohexanone recommended 1.1 Vol.% ($100^{\circ}C$) and 9.4 Vol.%, respectively. The lower flash points of cyclohexanone were experimented $42{\sim}43^{\circ}C$ by using closed-cup tester and $49{\sim}51^{\circ}C$ by using open cup tester. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for cyclohexanone and the experimental AIT of cyclohexanone was $415^{\circ}C$.

• Fire Science and Engineering
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• v.24 no.6
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• pp.76-81
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• 2010

For the safe handling of n-heptane, the explosion limit at $25^{\circ}C$, the temperature dependence of the explosion limits and the lower flash point were investigated. And AITs (auto-ignition temperatures) by ignition time delay for n-heptane were experimented. By using the literatures data, the lower and upper explosion limits of n-heptane recommended 1.0 Vol% and 7.0 Vol%, respectively. And the lower flash points of n-heptane recommended $-4^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-heptane and the experimental AIT of n-hexane was $225^{\circ}C$. The new equation for predicting the temperature dependence of the explosion limits of n-heptane is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

• 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.

• Journal of the Korean Institute of Gas
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• v.10 no.2 s.31
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• pp.33-39
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• 2006

For the safety design and operation of many gas process, it is necessary to know certain explosion limit, flash point, auto ignition temperature and minimum oxygen concentration of handling substances. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of propane, explosion limit and autoignition temperature of combustion characteristics for propane were investigated. By using the literatures data, the lower and upper explosion limits of propane recommended 2.0 vol% and 10.0 vol%, respectively. Also autoignition temperatures of propane with ignition sources recommended $450^{\circ}C$ at the electrically heated cruicible fumace(the whole surface heating) and recommended about $960^{\circ}C$ at the local hot surface. The new equations for predicting the temperature and the pressure dependence of the explosion limits of propane are proposed. The values calculated by the proposed equations were a good agreement with the literature data.