• Korean Chemical Engineering Research
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• v.53 no.5
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• pp.553-556
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• 2015

The usage of the correct combustion characteristic of the treated substance for the safety of the process is critical. For the safe handling of dimethylacetamide (DMAc) being used in various ways in the chemical industry, the flash point and the autoignition temperature (AIT) of DMAc was experimented. And, the lower explosion limit of DMAc was calculated by using the lower flash point obtained in the experiment. The flash points of DMAc by using the Setaflash and Pensky-Martens closed-cup testers measured $61^{\circ}C$ and $65^{\circ}C$, respectively. The flash points of DMAc by using the Tag and Cleveland automatic open cup testers are measured $68^{\circ}C$ and $71^{\circ}C$. The AIT of DMAc by ASTM 659E tester was measured as $347^{\circ}C$. The lower explosion limit by the measured flash point $61^{\circ}C$ was calculated as 1.52 vol%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.66-72
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• 2016

For the safe handling of Propionic Anhydride being used in various ways in the chemical industry, the flash point and the autoignition temperature(AIT) of Propionic Anhydride was experimented. And, the lower explosion limit of propionic anhydride was calculated by using the lower flash point obtained in the experiment. The flash points of propionic anhydride by using the Setaflash and Pensky-Martens closed-cup testers measured $60^{\circ}C$ and $61^{\circ}C$, respectively. The flash points of propionic anhydride by using the Tag and Cleveland open cup testers are measured $67^{\circ}C$ and $73^{\circ}C$. The AIT of propionic anhydride by ASTM 659E tester was measured as $280^{\circ}C$. The lower explosion limit by the measured flash point $60^{\circ}C$ was calculated as 1.37 Vol.%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.464-465
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• 2008

Concrete poles(CP) are popular supports for distribution lines. Various types of grounding electrode, such as copper-clad rods, have been used to maintain CP's ground resistance under the required value. The buried part of CP can also have structural grounding effect because of its iron reinforcing rods inside CPs. In this paper, we measured the total ground current injected into CP ground while measuring the ground current splitting to the metal electrode as well as the total injecting current. By this, it was able to measure the ground current splitting to CP structure. Based on the measured results, interrelationship between ground resistance of metal electrodes and current split factor to CP structure was analyzed.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.595-601
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• 2017

Background: Red ginseng oil (RGO) is produced by supercritical $CO_2$ extraction of secondary products derived from Korean Red Ginseng extract. As the use of RGO has increased, product safety concerns have become more important. Methods: In the present study, the subacute oral toxicity and bacterial reverse mutagenicity of RGO were evaluated. Sprague-Dawley rats were orally administered with RGO for 28 d by gavage. Daily RGO dose concentrations were 0 mg/kg body weight (bw), 500 mg/kg bw, 1,000 mg/kg bw, or 2,000 mg/kg bw per day. Bacterial reverse mutation tests included five bacterial strains (Escherichia coli WP2 and Salmonella typhimurium TA98, TA100, TA1535, and TA1537), which were used in the presence or absence of metabolic activation. The plated incorporation method for mutation test was used with RGO concentrations ranging from $312.5{\mu}g$ to $5,000{\mu}g$ per plate. Results: The subacute oral toxicity test results did not reveal any marked changes in clinical characteristics. There were no toxicological changes related to RGO administration in hematological and serum biochemical characteristics in either control or treatment animals. Furthermore, no gross or histopathological changes related to RGO treatment were observed. The bacterial reverse mutation test results did not reveal, at any RGO concentration level and in all bacterial strains, any increase in the number of revertant colonies in the RGO treatment group compared to that in the negative control group. Conclusion: The no-observed-adverse-effect level of RGO is greater than 2,000 mg/kg bw and RGO did not induce genotoxicity related to bacterial reverse mutations.

• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.10-14
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• 2007

Flash point is one of the major physical properties used to evaluate fire hazards of the combustible liquids. Properties showing relative fire hazards of the combustible liquids are heat release rate(HRR), peak heat release rate(PHRR), time to ignition(TTI), mass loss rate, and yield of $CO/CO_2$. The relationships between flash points and fire properties of the combustible liquids were examined in this study. For this study, mass loss rate and time to ignition were measured to calculate fire properties of the combustible liquids. The results showed that good correlations could be found between flash point and time to ignition, time to peak heat release rate, and the propensity to flashover. From a presented results, the parameters can be used to evaluate relative hazards of the combustible liquids on fire.

• Journal of the Korean Institute of Gas
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• v.14 no.1
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• pp.42-46
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• 2010

BOG(Boil Off Gas) is formed about 0.05 vol%/day from LNG(Liquefied Natural Gas) tanks of LNG receiving terminal. To recycle the BOG using direct contacting, Previously the quantities of LNG and BOG is mixed at the ratio of 11:1 by mass. However simple this process uses, there is the difficulty of processing operation resulted from decrease of using LNG in summer. To complement these shortcomings, Advantages of the process are investigated by comparison of cost and analysis of the indirect contact method using LNG cold energy. It was studied that principles and types of development using LNG cold energy which is abandoned in the carburettor and found how to contact each to find the appropriate cold energy development process. Therefore, in this research, the indirect contact method will be investigated the feasibility of a comparative analysis by using HYSYS.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.39-44
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• 2013

There have been large explosions at some chemical plants recently. Accidents in chemical plants have been caused mainly by servicing for maintenance. There is a need to find a key target for effective injury prevention in maintenance. In this paper, facilities were selected as a key target and the risk priority numbers of the facilities were calculated in order to prioritize preventative measures. The research method was based on the followings; the list of the facilities is found through injury analysis. Then, the risk of each facility was calculated by the frequency of accidents and the working day loss through injuries. In addition, the risk of the facilities was calculated again by the frequency and the severity based on knowledge and experience of experts. As a result, the facilities in chemical plant maintenance are ranked in order of high to low risk priority number; reactor, dryer, tank lorry, etc. In the future, special measures and attention should be directed according to the risk priority number during the maintenance of chemical plants.

• Journal of the Korean Institute of Gas
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• v.15 no.5
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• pp.19-24
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• 2011

Due to the latest industrial flow comes mainly switch to high-tech industries, combustible metals as Al, Mg, Li, Zn more require to use for the aircraft, car, cell phones, electronics and others. As a result, Increasing the processing of combustible metals due to increase in amount of combustible metals giving rise dust explosions also. Most Explosions caused by combustible metal dust, occurred in air cleaning device of local exhaust ventilation to capture and store the combustible dust. Therefore, this study was conducted to present and analyze technically that deformation and rupture shape of air cleaning device structure by Finite Element Analysis(FEA) rather than a simple prediction, in case of explosion occurs in an air cleaning device.

• Journal of the Korea Safety Management & Science
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• v.15 no.2
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• pp.121-128
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• 2013

The objectives of this study were to investigate the degrees of emotional labor, the effects to organizational effectiveness and the significant factors influencing organizational effectiveness in radiation therapy professional. The subjects of this study were the radiation therapists working at the hospital in Seoul and Gyungi. The self-reported questionnaires were administered to 205 radiation therapists and the data were analyzed with SPSS 19.0 package. The level of emotional labor of single or female subjects were revealed higher than married or male. The professionalism of job has significant correlation with emotional labor. Significant explanatory variables of the degrees of emotional labor included organization culture, distress and self-leadership. These three variables demonstrated the explanatory power of 13.9% of the emotional labor. Based on the findings, emotional labor of radiation therapist was correlated with occupational professionalism. These results suggest that the intervention program intervening emotional labor should be continued to develop in order to improve the effective self-leadership, organization culture and distress factor.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.171-176
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• 2012

Objective: The goal of this study was to assess work ability of Korean workers in the shipbuilding industry. Background: Old age is associated with inevitable time-dependent losses in physical capabilities. However the maintenance of physical capabilities is essential for continuing independence in old age. The work ability index(WAI) was constructed to reveal how well a worker is able to perform his or her work. Method: The WAI is a kind of survey methods developed to estimate the work capacity of aged workers by the Finish Institute of Occupational Health(FIOH) in 1998. The difference of the WAI between groups in each category was tested using the Kruskal-Wallis test, and the relationship between the WAI and the workers' ages was tested by the Correlation test. Results: This study surveyed 2,709 persons working in the shipbuilding industry in Korea. The average WAI score for all workers was 40.0 denoting a Good Level. Also, workers in the shipbuilding industry had lower work ability, as compared to the results of other industries. The WAI was analyzed for different age groups(${\leq}29$; 30~34; 35~39; 40~44; 45~49; 50~54; ${\geq}55$). The results of Kruskal-Wallis test showed that significant difference was identified on the effect of aging(p<0.05). Conclusion: Advanced countries like the Finland showed decreasing tendency in good and excellent levels as aged, but there was no decreasing tendency in Korean population. The results may be attributable to the general characteristics of Korean society, such as poor social security and burden caused by role of the patriarch. It may bring forth higher work ability in aged population even their physical condition is getting worse. Application: This finding could be used for developing more accurate assessment tool of work ability for working environment.