Corrosion Behavior of Hastelloy C-276 for Carbon-anode-based Oxide Reduction Applications

Jeon, Min Ku,Kim, Sung-Wook,Choi, Eun-Young Korean Radioactive Waste Society 2020 방사성폐기물학회지 Vol.18 No.3

The corrosion behavior of Hastelloy C-276 was investigated to identify its applicability for carbon-anode-based oxide reduction (OR), in which Cl₂ and O₂ are simultaneously evolved at the anode. Under a 30 mL·min^-1 Cl₂ + 170 mL·min^-1 Ar flow, the corrosion rate was less than 1 g·m^-2·h^-1 up to 500℃, whereas the rate increased exponentially from 500 to 700℃. The effects of the Cl₂-O₂ composition on the corrosion rate at flow rates of 30 mL·min^-1 Cl₂, 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂, and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂ with a constant 170 mL·min^-1 Ar flow rate at 600℃ was analyzed. Based on the data from an 8 h reaction, the fastest corrosion rate was observed for the 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂ case, followed by 30 mL·min^-1 Cl₂ and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂. The effects of the chlorine flow rate on the corrosion rate were negligible within the 5-30 mL·min^-1 range. A surface morphology analysis revealed the formation of vertical scratches in specimens that reacted under the Cl₂-O₂ mixed gas condition.

Corrosion Behavior of Inconel X-750 for Carbon Anode Oxide Reduction Application

Jeon, Min Ku,Kim, Sung-Wook,Lee, Sang-Kwon,Choi, Eun-Young Korean Radioactive Waste Society 2020 방사성폐기물학회지 Vol.18 No.3

The corrosion behavior of the Inconel X-750 alloy was investigated for its potential application under a Cl₂-O₂ mixed gas flow in an Ar atmosphere. The corrosion rate was found to be negligible at temperatures up to 400℃ under a flow rate of 30 mL·min^-1 Cl₂ + 170 mL·min^-1 Ar, whereas an exponential increase was observed in the corrosion rate at temperatures greater than 500℃. The suppression of the corrosion reaction due to the presence of O₂ was verified experimentally at flow rates of 30 mL·min^-1 Cl₂ (4.96 g·m^-2·h^-1), 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂ (2.02 g·m^-2 ·h^-1), and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂ (1.34 g·m^-2·h^-1) under a constant Ar flow rate of 170 mL·min^-1 at 600℃ for 8 h. The surface morphology analysis results revealed that porous surfaces with tunnel-type holes were produced under the Cl₂-O₂ mixed-gas condition. Furthermore, the effects of the Cl₂ flow rate on the corrosion rate were investigated, indicating that its impact was negligible within the range of 5-30 mL·min^-1 Cl₂ at 600℃.

Influence of Aeration Rate and Reactor Shape on Composting Poultry Manure and Sawdust

( Waqas Qasim ),( Min Ho Lee ),( Byeong Eun Moon ),( Jae Min Jo ),( Frank Gyan Okyere ),( Hyeon Tae Kim ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.2

We investigated various physicochemical properties, i.e., temperature, ammonia and carbon dioxide concentration, pH, electrical conductivity (EC), C/N ratio, organic matter content, moisture content, bacterial population, and seed germination index (GI), during the composting of poultry manure and sawdust for different aeration rates and reactor shapes. Three cylindrical-shaped and three rectangular-shaped laboratory-scale 60-L composting reactors were used in this study, with aeration rates of 0.3, 0.6, and 0.9 L min^-1kg^-1 (drymatter)DM. Results showed that the low aeration rate (0.3 L min^-1kg^-1DM) corresponded to a higher and longer thermophilic phase than did the high aeration rate (0.9 L min^-1kg^-1DM). Ammonia and carbon dioxide volatilization were directly related to the temperature profile of the substrate, with significant differences between the low and high aeration rates during weeks 2 and 3 of composting but no significant difference observed during week 1. At the end of our study, the final values of pH, EC, moisture content, C/N ratio, and organic matter in all compost reactors were lower than those at the start. The growth of mesophilic and thermophilic bacteria was directly related to the thermophilic and mesophilic condition of the compost. The final GI of the cylindrical reactor with an airflow rate of 0.3 L min^-1kg^-1DM was 82.3%, whereas the GIs of the other compost reactors were below 80%. In this study, compost of a cylindrical reactor with a low aeration rate (0.3 L min^-1kg^-1DM) was more stable and mature than the other reactors.

Determining the Optimal Cooking Time for Cooking Loss, Shear Force, and Off-Odor Reduction of Pork Large Intestines

Sung-Su Kim,Yee Eun Lee,ho Hyun Kim,Joong-Seok Min,Dong Gyun Yim,Cheorun Jo 한국축산식품학회 2022 한국축산식품학회지 Vol.42 No.1

The objective of this study was to determine the optimal cooking time by considering the cooking loss, shear force, and off-odor reduction of pork large intestines. Commercial pork large intestines were purchased, quartered perpendicularly, and cooked in boiling water for 40, 120, 180, and 240 min. Cooking loss of the samples increased after 240 min of cooking (10.92, p<0.05) while shear force value was lower at 240 min (4.45) compared to that at other cooking times (p<0.001). The amount of major volatile organic compounds showed a decreasing trend with increasing cooking time. In particular, the amount of methyl pentanoate (17,528.71) and methyl isobutyrate (812.51), compounds with a relatively low odor threshold, decreased significantly after 120 min of cooking and no change was observed thereafter (p<0.05). In addition, the amount of 2-pentanol (3,785.65) and 1-propanol (622.26), possibly produced by lipid oxidation, significantly decreased at the same cooking time (p<0.001). In the principal component analysis, only the 40 min cooking time was significantly different from other cooking time by high amounts of 1-propanol, 2-pentanol, and methyl isobutyrate. In conclusion, in the present study, the optimal cooking time for pork large intestines was 120 min in terms of off-odor reduction, cooking loss, and shear force.

Silymarin Inhibits Cytokine-Stimulated Pancreatic Beta Cells by Blocking the ERK1/2 Pathway

( Eun Jeong Kim ),( Jee Ho Kim ),( Min Young Lee ),( Muddenahalli Srinivasa Sudhanva ),( Sundaravinayagam Devakumar ),( Young Jin Jeon ) 한국응용약물학회 2014 Biomolecules & Therapeutics(구 응용약물학회지) Vol.22 No.4

We show that silymarin, a polyphenolic fl avonoid isolated from milk thistle (Silybum marianum), inhibits cytokine mixture (CM: TNF-α, IFN-γ, and IL-1β)-induced production of nitric oxide (NO) in the pancreatic beta cell line MIN6N8a. Immunostaining and Western blot analysis showed that silymarin inhibits iNOS gene expression. RT-PCR showed that silymarin inhibits iNOS gene expression in a dose-dependent manner. We also showed that silymarin inhibits extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) phosphorylation. A MEK1 inhibitor abrogated CM-induced nitrite production, similar to silymarin. Treatment of MIN6N8a cells with silymarin also inhibited CM-stimulated activation of NF-κB, which is important for iNOS transcription. Collectively, we demonstrate that silymarin inhibits NO production in pancreatic beta cells, and silymarin may represent a useful anti-diabetic agent.

NURB 곡선을 이용한 GIS 도체표면의 전계최적화

민석원,박은서 순천향대학교 부설 산업기술연구소 2001 순천향 산업기술연구소논문집 Vol.7 No.2

This paper aims at the design of 170 kV GIS conductor surface under a certain specified field condition by using NURB curves. We used 170 kV GIS model as initial shape and selected the reference electric field on the GIS conductor surface as 1.2 kV/min which was middle between average value and maximum value on it. We found the maximum electric field on conductor surface was 1.25kV/min and other parts was converged in 1.2 kV/min when we optimized the total part of 170 kV GIS conductor surface by using two shape variables.

갑상선 기능항진증 환자에서 인슐린감수성 및 인슐린분비능의 변화

최은진,강호철,이태희,정민영,이대호,장연진,박상선,조재현 대한내분비학회 1994 Endocrinology and metabolism Vol.9 No.2

The impairement of glucose metabolism is frequently associated in hyperthyroidism. The present study was performed to determine the effect of the thyroid hormone excess on insulin sensitivity and on insulin secretory function in vivo. Ten newly diagnosed hyperthyroid patients and fifteen healthy control subjects were subjected to frequently sampled intravenous glucose tolerance tests(FSIGT) after an overnight fast. Insulin sensitivity, represented by the insulin sensitivity index(S_1), was assessed by minimal model analysis of FSIGT data. Insulin secretion was measured by the total area under the insulin curve after glucose load. The results were as follows. 1) The K_G values, which represent glucose tolerance, were not different between the hyperthyroid patients and the normals(2.2+-0.3 vs. 2.5+-0.3%/min, p$gt;0.05). 2) S_1 was significantly decreased in the hyperthyroid patients in comparison to the normals(7.5+-1.4 vs. 2.6+-0.3X10^-4 min^-1/uU/ml, p$lt;0.05). 3) The basal insulin concentration was higher in the hyperthyroid patients than in the normals(8.3+-2.4 vs. 4.6+-0.4 uU/ml, p=0.07). In addition, the insulin secretory response to a glucose load was increased in the hyperthyroid patients as evidenced by the peak plasma insulin level(168.2+-30.4 vs. 89.2+-13.9 uU/ml, p$lt;0.05) and by the total area under the insulin curve(2641.1+-443.2 vs. 1696.7+-204.3 min uU/ml, p$lt;0.05). These results clearly demonstrated that insulin sensitivity was impaired in these newly diagnosed hyperthyroid patients. However, glucose tolerance was maintained by the increased insulin secretion (J Kor Soc Endocrinol 9:108-114, 1994).

오이 추출물에 존재하는 Superoxide Dismutase의 열안정성

김은애(Eun-Ae Kim),김기남(Gi-Nahm Kim),길지은(Ji-Eun Kil),이민경(Min-Kyung Lee),김석환(Suk-Hwan Kim),서정식(Chung-Sik Suh),박인식(Inshik Park) 한국식품영양과학회 1999 한국식품영양과학회지 Vol.27 No.6

오이속의 조효소액에 존재하는 Superoxide dismutase(SOD)활성의 pH 안정성은 pH 8.0에서 가장 안정하였고 pH5.0~9.0 사이의 범위에서는 비교적 안정하였다. 최적 온도는 25℃였고 열 안정성은 60℃까지는 안정하였다. 100℃에서 5분간 보관하였을 경우에는 12%만이 남아있었다. 오이에 존재하는 SOD 활성이 섭취 후에도 안정한가를 확인하기 위한 실험에서는 위속의 pH와 동일하도록 오이속의 조효소액의 pH를 2.0으로 변형시킨 후 36.7℃에서 3시간 동안 보관 후에 잔존활성이 10%였고, 장내의 환경인 pH 7.0으로 바꾸어 6시간 동안 둔 후 잔존하는 SOD의 활성은 25%로 활성이 증가되었다. 다양한 열처리 후에 잔존하는 오이의 SOD활성은 오이속은 데치기에서(끓는 물에서 2분) 25%, 껍질은 찌는 동안에(3분) 53%, 그리고 속과 껍질로 분리하지 않은 오이는 데치기에서 27%의 활성잔존률을 보였다. 4℃에서는 20일간 보관한 후에 오이속의 조효소액은 81%활성이 있었고, 30℃에서는 17%의 활성이 남아 있었다. 투석한 결과 SOD의 활성은 변화가 없었으므로 오이속에 존재하는 SOD는 적어도 분자량이 12,000 이상의 물질로 추정된다. The superoxide dismutase(SOD) in peeled pericarp of cucumber was most stable at pH 8.0 and relatively stabe between pH 5.0 and 9.0. The enzyme was stable up to 60℃ and retained 12% by heat treatment at 100℃ for 5 min. At pH 2.0, the peeled pericarp enzyme activity was decreased to 10% by incubation for 3 hrs. However, the enzyme activity was increased above 25% after incubating the enzyme at pH 7.0 for 6 hrs. Retention of SOD activity in cucumber by various heating methods was also measured. The residual SOD activities of peeled pericarp and whole cucumber was estimated to be 25% and 27% after blanching (2 min), respectively. The skin enzyme retained 53% of its activity after steaming (3 min). When the peeled peri carp enzyme was incubated at 4℃ for 20 days, the enzyme activity remained about 81%. However, when the enzyme incubated at 30℃ for 20 days, the peeled pericarp enzyme activity decreased to 17% of its original activity. The enzyme activity of peeled pericarp cucumber was not changed after exhaustive dialysis for 3 days, which indicated that the SOD activity in cucumber seems to have molecular weight above 12,000.

Skin entrance dose for digital and film radiography in Korean dental schools

Cho, Eun-Sang,Choi, Kun-Ho,Kim, Min-Gyu,Lim, Hoi-Jeong,Yoon, Suk-Ja,,Kang, Byung-Cheol 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.4

Purpose : This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods : Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results : The median dose was 491.2 μGy for digital radiography and 1,205.0 μGy for film radiography. The skin entrance dose digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion : Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

Monacolin K 대량생산 Monascus 균주의 탐색 및 동정

곽은정(Eun Jung Kwak),이효민(Hyo Min Lee),임성일(Seong Il Lim) 한국식품영양과학회 2004 한국식품영양과학회지 Vol.33 No.1

최근 콜레스테롤 합성을 억제하는 효능을 가진 것으로 알려진 홍국균 대사생성물의 일종인 monacolin K를 이용한 건강식품의 개발에 대한 관심이 높아지고 있다. 이에 본 연구에서는 monacolin K를 이용한 건강식품의 개발을 위한 기초연구로 monacolin K의 생산 효율성을 높이고자 미동정된 1종의 홍국균을 포함해 29종의 홍국균을 수집하여 monacolin K를 대량생산하는 균주를 탐색하였다. 홍국은 PDA배지에서 배양한 홍국균을 침지ㆍ증자한 백미에 5%가 되도록 접종 후, 30℃에서 10일간 배양하여 제조하고 이를 건조, 분말로 하여 사용하였다. 그 결과 색소생성량이 많은 M. purpureus ATCC 16457, M. purpureus IFO 32316, M. purpureus IFO 32228, M. kaoliang ATCC 46595, M. kaoliang ATCC 46596 등의 균체를 배양한 홍국에서 monacolin K 생성량도 높았다. 그러나 색소와 monacolin K 생산량은 미동정된 홍국균이 가장 많은 것으로 나타나 형태학적 관찰과 ITS 및 28S rRNA 부분 유전자 염기서열분석을 실시한 결과, M. purpureus CBS 281.34인 것으로 동정되었다. We had screened the Monascus strain capable of producing monacolin K dominantly among 29 Monascus strains. Red yeast rice was prepared by culturing each Monascus sp. with 200 g of steamed rice (120℃, 20 min) at 30℃ for 10 days and drying at 80℃ for 20 min. As a result, red yeast rice cultured by M. purpureus ATCC 16457, M. purpureus IFO 32316, M. purpureus IFO 32228, M. kaoliang ATCC 46595 and M. kaoliang ATCC 46596 produced lots of red pigment and monacolin K. An unidentified Monascus sp. showed the highest productivity of red pigment and monacolin K among 29 Monascus strains. Its production of red pigment and monacolin K was 1.3~39 times and 2.4~8 times higher than other strains, respectively. Although the morphorogical characteristics of unidentified Monascus strain were a little different from the typical M. purpureus, it was identified as M. purpureus CBS 281.34 from the result of sequencing of ITS (Internal transcribed spacer) and 28S ribosomal RNA (partial).