• Corrosion Science and Technology
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• v.21 no.6
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• pp.466-475
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• 2022

Surface oxides and intergranular (IG) oxidation phenomena in Alloy 600 depending on hydrogen concentration were characterized to obtain clear insight into the primary water stress corrosion cracking (PWSCC) behavior upon exposure to pressurized water reactor primary water. When hydrogen concentration was between 5 and 30 cm³ H₂/kg H₂O, NiFe₂O₄ and NiO type oxides were found on the surface. NiO type oxides were found inside the oxidized grain boundary when hydrogen concentration was 5 cm³ H₂/kg H₂O. However, only NiFe₂O₄ spinel on the surface and Ni enrichment were observed when hydrogen concentration was 30 cm³ H₂/kg H₂O. These results indicate that the oxidation/reduction reaction of Ni in Alloy 600 depending on hydrogen concentration can considerably affect surface oxidation behavior. It appears that the formation of NiO type oxides in a Ni oxidation state and Ni enrichment in a Ni reduction (or metallic) state are common in primary water. It is believed that the above different oxidation/reduction reactions of Ni in Alloy 600 depending on hydrogen concentration can also significantly affect the resistance to PWSCC of Alloy 600.

• Fire Science and Engineering
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• v.32 no.5
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• pp.112-121
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• 2018

In the present study, a group of subjects consisting of "Fire Professional Engineers" was selected to examine the effects of life safety awareness and safety behaviors of the subjects on life safety through an analyses of the descriptive statistics, factors, reliability, and correlation; simple regression and three-stage regression analyses on mediation were also carried out based on the hypotheses developed. The results showed that the degree of safety behavior increased by 72.1% in accordance with the increased safety awareness of fire professional engineers; the life safety was also increased by 61.5% and 64.5% by the increases in safety awareness and safety behavior of fire professional engineers, respectively. In addition, the safety behaviors demonstrated a partial mediatory effect in the relationship between safety awareness and life safety. All hypotheses (H1, H2, H3, H4), established for the present study, were accepted based on statistical verifications that justified an amendment of the Acts pertinent to firefighting service focusing on life safety; the data are expected to be exploited to reflect significance of life safety.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.477-479
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• 2000

This paper presents an analysis which compares the effectiveness of different temporary safety grounding methods on working overhead distribution system. The analysis studied direct energization at fault conditions with seven scenarios. The results show that the scenario, single point safety grounding on the working pole with brackets Pairs spaced 2 km apart on both side of a work site is safest grounding method. This can be used to evaluate lineman safety on a overhead distribution systems in Korea.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.6
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• pp.670-676
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• 2016

Hydrogen town in Republic of Korea was established in 2013. Hydrogen as a byproduct produced by various processes of factories is used in hydrogen town facilities. As cell performance is affected by contaminations in fuel gas, various standards about impurities of fuel have been determined by many countries. This study shows performance degradation of single cell with impurities concentrations. Traces of carbon monoxide (CO) and hydrogen sulfide ($H_2S$)can cause considerable cell performance losses. For comparing the performances by poisoning of CO, acceleration test, I-V curve, constant current are performed. Both the CO and $H_2S$ poisoning rate are a function of their concentration. With the higher concentrations the higher poisoning rates are observed. And, it was confirmed that, oxidation behavior and side reaction generation are not affected. Under the lower $H_2S$ concentration condition, the poisoning rate is much higher than that of CO because of its different adsorption intensity. It can be possible that the result of this study can be used for enacting regulation as a baseline data.

• Journal of the Korea Safety Management & Science
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• v.8 no.2
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• pp.61-70
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• 2006

The likelihood of failure by the corrosion of high temperature $H_2S/H_2$, which affect to a risk of facilities, was analyzed through the risk based-inspection using API-581 BRD. We found that the corrosion rate was increased as temperature and $H_2S$ concentration were increased. Also, the technical module subfactor(TMSF) was increased as an used you increased, material thickness decreased, inspection number decreased, and inspection effectiveness increased. In these conditions, the maximum value of TMSF was not varied, but the TMSF was sensitively varied at low temperature for high concentration of $H_2S$.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.99-108
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• 2020

Objectives: This study aimed to compare the regulatory systems for laboratory safety and health management between Korea and Germany and discuss the implications. Methods: Laboratory safety and health regulations for legal enforcement and relevant technical guidelines in Korea and Germany were reviewed. Results: Lab safety and health management is enforced by the Act on the Establishment of Safe Laboratory Environment in Korea. Most provisions focus on supervisory control, that is, the principal's liability is emphasized. In addition, there is a lack of laboratory-specific procedures for safety and health management in the act since it is stipulated that other relevant regulations apply to some technical contents. Non-compulsory technical guidelines for lab safety and health management are also provided by the Korea Occupational Safety and Health Agency (KOSHA) in order to enable researchers to follow safe procedures. There is no independent regulation for lab safety and health in Germany, and it is also governed by several regulations. The German Social Accident Insurance Institute provides technical guidelines on lab safety and health, and these contain more specific content to allow them to be followed more easily compared to the KOSHA guidelines. The most remarkable differences between the regulation of each country were contents of the risk assessment and specific protect measures from hazardous agents. Conclusions: Regulatory control is an essential way to prevent accidents, but it is more important to create an environment in which all stakeholders, including individual lab members, are allowed to participate actively in safety and health management activities.

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.6
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• pp.382-388
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• 2023

In this study, hydrogen embrittlement (HE) behavior of a SA-723 steel via controlling gaseous hydrogen pre-charging condition has been analyzed. The gaseous hydrogen charging of the SA-723 steel was performed under a constant pressure of 20 MPa of gaseous H₂ at 150℃ and 300℃ for 2 and 6h, and TDS, SSRT and Charpy tests were conducted to analyze the hydrogen embrittlement (HE) behavior of the SA-723 steel. Furthermore, prior to commencing the test, these specimens were coated with Zn to prevent hydrogen from diffusing out of a specimen during the tests. The TDS results showed that the 300℃-6h and 150℃-6h charged steels contain larger amounts of hydrogen than 300℃-2h and 150℃-2h charged steel. The SSRT and Charpy test results also showed the similar trends that the mechanical properties of the steels deteriorate as the amount of hydrogen charged in the steel increases. Therefore, this study suggests that, for SA-723 steel, the charging time parameter is more effective to charge more amount of hydrogen into SA-723 steel, rather than the charging temperature.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.688-691
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• 2004

Concentrations of PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-c,d)pyrene] in vegetable oils and fats available in Korean market were estimated. Involved methodology were liquid-liquid partition, purification on Sep-Pak Florisil Cartridges, and high performance liquid chromatography using fluorescence detector. Overall recoveries for eight PAHs spiked into vegetable oils and fats ranged from 68.2 to 101.5%, averaging 85.4%. Mean levels of benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene in vegetable oils and fats were 0.53, 0.82, 0.50, 0.18, 0.35, 0.16, 0.31, and $0.44{\mu}g/kg$, respectively.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.145-151
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• 2018

In this study, the track-bridge interaction analysis was performed using an analytical model considering the track structure, thereby taking into account the linear conditions (R=650 m, cant variation $160{\pm}60mm$) and the dynamic characteristics of the bridge. As a result of the study, the allowable speed on the example bridge considered was calculated at 200 km/h based on vertical deflection, vertical acceleration, and irregularity in longitudinal level, but was also evaluated at 170km/h based on the coefficient of derailment, wheel load reduction, and lateral displacement of the rail head. It is considered desirable to set the speed 170km/h to the speed limit in order to secure the safety of both the bridge and the track. It is judged that there will be no problems with ensuring rail protection and train stability in the speed band.