• 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.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.13-18
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• 2007

The multivariate statistical analysis, using the multiple linear regression(MLR), have been applied to analyze and predict the flash points of binary systems. Prediction for the flash points of flammable substances is important for the examination of the fire and explosion hazards in the chemical process design. In this paper, the flash points are predicted by MLR based on the physical properties of pure substances and the experimental flash points data. The results of regression and prediction by MLR are compared with the values calculated by Raoult's law and Van Laar equation.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.115-124
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• 2017

The objective of study was to investigate the optimal echo phase for mouse brain enhancement scan using fast low angle shot (FLASH) sequence of 9.4T magnetic resonance imaging (MRI). For quantification based on this method, an MR phantom experiment and clinical research were done. The phantom experiment was conducted by fabricating three phantoms with different molar concentration of gadolinium to create changes in echo phase of 9.4T FLASH sequence used in mouse brain scans. In the phantom experiment, SSI was 25~27 [arbitrary units, a.u.] in each of 33 phases from $6{\pi}$ to $28{\pi}$, while RSP was 30~100 mmol. MPSI was 47~52 [a.u], while MPP, where MPSI is seen, was 0.8~9 mmol. EPMS was 80.8~108.0%, while ASIMP was formed between 21.1 and 31.8 [a.u]. In the clinical research, Finally, the occurrence rate of artifact that expressed -1 nd +1. The present study was able to quantify the degree of enhancement at FLASH sequence of 9.4T MRI, as well as identify the optimal echo phase during mouse brain enhancement scan.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.120-126
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• 1999

This study was accomplished by measuring the lower and upper flash point with air blowing method and grasping the characteristics of flammability for the three component systems, which are made up of the Benzene-Toluene-o-Xylene and Methylethylketone-Toluene-o-Xylene. These three component systems are widely used in the various industrial fields together with the development of industry. The results are as follows ; 1 ) Isothermal line is plotted on the triangular diagram for flash points determined in each solutions. From this line, the mixed compositions which indicated the same lower and upper flash points in each different composition could be read on this diagram, if the composition of mixtures are known. 2) Lower and upper explosion limits obtained from the flash points determined for the three component solution are compared with the value calculated from Le Chatelier's law. Especially the lower explosion limits are in a good agreement with the calculated values.

• International Journal of Safety
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• v.7 no.2
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• pp.12-16
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• 2008

Lower flash points for the binary systems, carbon tetrachloride+o-xylene and water+n-butanol were measured by Pensky-Martens closed cup tester. The Raoult's law and optimization method using van Laar equation were used to predict the lower flash points and were compared with experimental data. The calculated values based on the optimization method were found to be better than those based on the Raoult's law.

• Fire Science and Engineering
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• v.22 no.5
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• pp.79-82
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• 2008

Biodiesel is manufactured from vegetable oils, etc. in reaction with methanol so that the product of biodiesel may be dangerous due to the methanol remained of it. The risks of methanol remained in biodiesel were studied by measuring flash points and dynamic viscosity to some samples of biodiesel by adding methanol to a certain percentage of. The results of flash points of biodiesel are decreased in accordance with increasing of methanol in biodiesel and also decreasing the dynamic viscosity. It was shown that the risks of explosion of biodiesel are significantly high due to lower flash points resulted from methanol remained in biodiesel fuel as a reactant or adding to biodiesel for reduction of viscosity.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.67-72
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• 2008

The lower flash points for the flammable binary systems, 2-propanol+formic acid and 2-propanol+n-butyric acid, were measured by Cleveland open cup tester. The optimization method using van Laar equation and the Raoult's law were used to estimate the lower flash points and were compared with experimentally-derived data. The calculated values based on the optimization method were found to be better than those based on the Raoult's law.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.66-76
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• 2003

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.4
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• pp.148-159
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• 2007

Purpose: Vasomotor symptoms including hot flash are very common to postmenopausal women. Estrogen therapy was regarded as the best option for relieving menopausal symptoms until 2002, when the Women#s Health Initiative(WHI) reported the side effect of the therapy. Consequently, studies on the complementary and alternative medical herbs and therapy for the management of menopausal symptoms have followed. And so we have reviewed some international clinical studies about the management of postmenopausal symptoms with acupuncture therapy. Methods: "Menopause and acupuncture" was designated as a key word in the search site. Pub Med, and nine papers dealing with hot flash among the relevant RCTs were selected, and then, the effect of acupuncture on hot flash and the way the researches had been done was examined. Results : The intensity of hot flash reduced significantly and the frequency of hot flash was inclined to reduce, but not significantly, compared to the controlled group. Conclusion: Each clinical test has its limitations in point of the number of the required samples. However, it still shows the possibility that acupuncture itself will be effective enough to reduce the intensity of hot flash to a certain degree. It is believed that extensive clinical tests on the effect of acupuncture on hot flash will need to be done hereafter. And when the tests are carried out, it is required to exclude placebo effect, do blind test, and carefully select and control the methods.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.717-724
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• 2010

The flash point is one of the most important physical properties used to determine the potential for fire and explosion hazards of flammable liquids. Despite the needs of the experimental flash point data for the design and construction of chemical plants, there is often a significant gap between the demands for the data and their availability. This study have built and compared two models of partial least squares(PLS) and support vector machine(SVM) to predict the experimental flash points of 893 organic compounds out of DIPPR 801. As the independent variables of the models, 65 functional groups were chosen based on the group contribution method that was oriented from the assumption that each fragment of a molecule contributes a certain amount to the value of its physical property, and the logarithm of molecular weight was added. The prediction errors calculated from cross-validation were employed to determine the optimal parameters of two models. And, an optimization technique should be used to get three parameters of SVM model. This work adopted particle swarm optimization that is one of heuristic optimization methods. As the selection of training data can affect the prediction performance, 100 data sets of randomly selected data were generated and tested. The PLS and SVM results of the average absolute errors for the whole data range from 13.86 K to 14.55 K and 7.44 K to 10.26 K, respectively, indicating that the predictive ability of the SVM is much superior than PLS.