http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Risk-informed Emergency Response Training for Backdraft in Nuclear Power Plants
Mihyun Kim,Wonkook Kim,Hongki Kim,Jungman Kim,Sunhong Yoon,Jangwon Choi,Heemoon Kim 한국화재소방학회 2023 International Journal of Fire Science and Engineer Vol.37 No.3
Research has been conducted for developing fire evacuation and response training programs for nuclear power plant (NPP) application. Among numerous fire scenarios that may occur in an NPP environment, three different points of origin for a fire were selected for the program based on a risk-informed approach: switchgear room, main control room, and safety injection pump room. Fire outcomes were predicted for these scenarios via numerical modeling and the results were incorporated into the newly developed fire evacuation and response training program for the APR1400, Korea’s next-generation NPP model. The switchgear room fire scenario was found to have the most potential for backdraft to occur during manual fire response following automatic gaseous fire suppression system activation. The emergency response manual does discuss this possible backdraft occurrence; however, the guidance to avoid injuries is qualitative, such as to be cautious of backdrafts and wait a sufficient amount of time after opening a door before entering the. In this study, backdraft phenomenon that may occur from a switchgear room fire was numerically examined using the recent version of the Fire Dynamics Simulator to develop an appropriate timeline to be implemented in the fire evacuation and response training program. Based on the findings, the following guidance is provided: (1) backdraft can only occur when the fire originates in the space near the door; (2) wait at least 10 minutes after opening the door before entering the room; (3) watch for rapid smoke production, as this may be an antecedent phenomenon of backdraft; and (4) when smoke production increases rapidly, leave the room as soon as possible to avoid being caught within the deflagrating flames from a backdraft.
Electrochemical Corrosion Behavior of Iron in Lithium-ion Battery Electrolyte
Kim, Jineun,Lee, Suhyun,Kim, Kun Woo,Son, Jungman,Mun, Junyoung The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.4
The element iron (Fe) is affordable and abundantly available, and thus, it finds use in a wide range of applications. As regards its application in rechargeable lithium-ion batteries (LIBs), the electrochemical reactions of Fe must be clearly understood during battery charging and discharging with the LIB electrolyte. In this study, we conducted systematic electrochemical analyses under various voltage conditions to determine the voltage at which Fe corrosion begins in general lithium salts and organic solvents used in LIBs. During cyclic voltammetry (CV) experiments, we observed a large corrosion current above 4.0 V (vs. Li/Li<sup>+</sup>). When a constant voltage of 3.7 V (vs. Li/Li<sup>+</sup>), was applied, the current did not increase significantly at the beginning, similar to the CV scenario; on the other hand, at a voltage of 3.8 V (vs. Li/Li<sup>+</sup>), the current increased rapidly. The impact of this difference was visually confirmed via scanning electron microscopy and optical microscopy. Our X-ray photoelectron spectroscopy measurements showed that at 3.7 V, a thick organic solid electrolyte interphase (SEI) was formed atop a thin fluoride SEI, which means that at ≥3.8 V, the SEI cannot prevent Fe corrosion. This result confirms that Fe corrosion begins at 3.7 V, beyond which Fe is easily corrodible.
Effects of the Antibiotics Growth Promoter Tylosin on Swine Gut Microbiota
( Jungman Kim ),( Robin B. Guevarra ),( Son G. Nguyen ),( Ji Hoon Lee ),( Dong Kee Jeong ),( Tatsuya Unno ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.5
Tylosin has been used as a livestock feed additive and antibiotic growth promoter for many years. However, the mode of action by which tylosin enhances animal growth is unclear. We used high-throughput sequencing of 16S rRNA genes to investigate the effects of tylosin as a feed additive on swine gut microbiota. No significant difference in the rate of weight increase was observed between control and tylosin-treated pigs during a 10-week feeding trial. However, tylosin-treated pigs showed rapid increases in the relative abundance of the phylum Firmicutes. Increases in Firmicutes species are associated with (so-called) obese-type gut microbiota. The abundance of species of four families of the phylum Firmicutes (Streptococcaceae, Peptococcaceae, Peptostreptococcaceae, and Clostridiaceae) correlated positively with host weight gain. The abundance of Streptococcaceae family bacteria was least affected by tylosin treatment. Distribution analysis of operational taxonomic units (OTUs) showed that both control and tylosin-treated pigs exhibited similar OTU alterations during growth. However, the tylosin-treated group showed distinctive alterations in gut microbiota when the host weighed approximately 60 kg, whereas similar alterations occurred at around 80 kg in the control group. Our results suggest that use of tylosin accelerates maturation of swine gut microbiota rather than altering its composition.
Laminarin favorably modulates gut microbiota in mice fed a high-fat diet
Nguyen, Son G.,Kim, Jungman,Guevarra, Robin B.,Lee, Ji-Hoon,Kim, Eungpil,Kim, Su-il,Unno, Tatsuya The Royal Society of Chemistry 2016 Food & Function Vol.7 No.10
<P>We investigated the anti-obesity effects of the potential prebiotic, laminarin, on mice fed a high-fat diet. A metagenomics approach was applied to characterize the ecological and functional differences of gut microbiota among mice fed a normal diet (CTL), a high-fat diet (HFD), and a laminarin-supplemented high-fat diet (HFL). The HFL mice showed a slower weight gain than the HFD mice during the laminarin-feeding period, but the rate of weight gain increased after the termination of laminarin supplementation. Gut microbial community analysis showed clear differences between the CTL and HFD mice, whereas the HFL mice were between the two. A higher abundance of carbohydrate active enzymes was observed in the HFL mice compared to the HFD mice, with especially notable increases in glycoside hydrolase and polysaccharide lyases. A significant decrease in Firmicutes and an increase in the Bacteroidetes phylum, especially the genus<I>Bacteroides</I>, were observed during laminarin ingestion. Laminarin ingestion altered the gut microbiota at the species level, which was re-shifted after termination of laminarin ingestion. Therefore, supplementing laminarin could reduce the adverse effects of a high-fat diet by shifting the gut microbiota towards a higher energy metabolism. Thus, laminarin could be used to develop anti-obesity functional foods. Our results also suggest that laminarin would need to be consumed regularly in order to prevent or manage obesity.</P>
Is routine nasogastric tube insertion necessary in pancreaticoduodenectomy?
Yoon Young Choi,Jungman Kim,Daekwan Seo,Dongho Choi,Min Joo Kim,Jung Hoon Kim,Kyung-Jae Lee,Kyung Yul Hur 대한외과학회 2011 Annals of Surgical Treatment and Research(ASRT) Vol.81 No.4
Purpose: The necessity of nasogastric decompression after abdominal surgical procedures has been increasingly questioned for several years. Traditionally, nasogastric decompression is a mandatory procedure after classical pancreaticoduodenectomy (PD); however, we still do not know whether or not it is necessary for PD. The present study was designed to assess the clinical benefit of nasogastric decompression after PD. Methods: Between July 2004 and May 2007, 41 consecutive patients who underwent PD were enrolled in this study. Eighteen patients were enrolled in the nasogastric tube (NGT) group and 23 patients were enrolled in the no NGT group. Results: There were no differences in the demographics, pathology, co-morbid medical conditions, and pre-operative laboratory values between the two groups. In addition, the passage of flatus (P = 0.963) and starting time of oral intake (P = 0.951) were similar in both groups. In the NGT group, 61% of the patients complained of discomfort related to the NGT. Pleural effusions were frequent in the NGT group (P = 0.037); however, other post-operative complications, such as wound dehiscence and anastomotic leakage, occurred similarly in both groups. There was one case of NGT re-insertion in the NGT group. Conclusion: Routine nasogastric decompression in patients undergoing PD is not mandatory because it has no clinical advantages and increases patient discomfort.
Soo-Min Ha,Shin Hwang,Gi-Won Song,Chul-Soo Ahn,Deok-Bog Moon,Tae-Yong Ha,Dong-Hwan Jung,Gil-Chun Park,Ki-Hun Kim,Dae-Yeon Kim,Jungman Namgung,Woo-Hyoung Kang,Seok-Hwan Kim,Eunkyoung Jwa,Jae-Hyeon Kwon 한국간담췌외과학회 2017 Annals of hepato-biliary-pancreatic surgery Vol.21 No.4
Backgrounds/Aims: Model for End-stage Liver Disease (MELD) score was adopted in June 2016 in Korea. Methods: We analyzed changes in volumes and outcomes of deceased donor liver transplantation (DDLT) for 1 year before and after introduction of MELD scoring at Asan Medical Center. Results: There were 64 cases of DDLT in 1 year before MELD introduction and 106 in 1 year after MELD introduction, an increase of 65%. The volume of DDLTs abruptly increased during first 3 months, but then returned to its usual level before MELD introduction, which indicated 3-month depletion of accumulated recipient pool with high MELD scores. The number of pediatric DDLT cases increased from 3 before MELD introduction to 11 after it, making up 21.4% and 47.8% of all cases of pediatric liver transplantation, respectively. The number of cases of retransplanted DDLTs increased from 4 to 27, representing 6.3% and 25.5% of all DDLT cases, respectively. The number of status 1 DDLT cases increased from 5 to 12, being 7.8% and 11.3% of all cases. Patient survival outcomes were similar before and after MELD introduction. Conclusions: The number of DDLTs temporarily increased after adoption of MELD scoring due to accumulated recipient pool with high MELD scores. The numbers of retransplanted and pediatric DDLT cases significantly increased. Patient survival in adult and pediatric DDLT was comparable before and after adoption of MELD scoring. These results imply that Korean MELD score-based allocation system was successfully established within its first year.