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℃.

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.

Ultrasonic Degradation of Endocrine Disrupting Compounds in Seawater and Brackish Water

So Young Park,Jong Sung Park,Ha Yoon Lee,Ji Yong Heo,Yeo Min Yoon,Kyung Ho Choi,Nam Guk Her 대한환경공학회 2011 Environmental Engineering Research Vol.16 No.3

In this study, a series of experiments was conducted on the relative degradation of commonly known endocrine-disrupting compounds such as bisphenol A (BPA) and 17α-ethinyl estradiol (Ee₂) in a single-component aqueous solution using 28 and 580 kHz ultrasonic reactors. The experiments were conducted with three different types of model water: deionized water (DI), synthetic brackish water (SBW), and synthetic seawater (SSW) at pH 4, 7.5, and 11 in the presence of inert glass beads and humic acids. Significantly higher sonochemical degradation (93-97% for BPA) occurred at 580 kHz than at 28 kHz (43-61% for BPA), regardless of water type. A slightly higher degradation was observed for Ee₂ compared to that of BPA. The degradation rate of BPA and Ee₂ in DI water, SBW, and SSW after 30 min of ultrasound irradiation at 580 kHz increased slightly with the increase in pH from 4 (0.073-0.091 min-1 for BPA and 0.081-0.094 min-1 for Ee₂) to 7.5 (0.087-0.114 min-1 for BPA and 0.092?0.124 min-1 for Ee₂). In contrast, significant degradation was observed at pH 11 (0.149-0.221 min-1 for BPA and 0.147-0.228 min-1 for Ee₂). For the given frequencies of 28 and 580 kHz, the degradation rate increased in the presence of glass beads (0.1 mm and 25 g) for both BPA and Ee₂: 0.018-0.107 min-1 without beads and 0.052-0.142 min-1 with beads for BPA; 0.021-0.111 min-1 without beads and 0.054-0.136 min-1 with beads for Ee₂. A slight increase in degradation of both BPA and Ee₂ was found as the concentration of dissolved organic carbon (DOC, humic acids) increased in both SBW and SSW: 0.107-0.115 min-1 in SBW and 0.087-0.101 min-1 in SSW for BPA; 0.111-0.111 min-1 in SWB and 0.092-0.105 min-1 in SSW for Ee₂. After 30 min of sonicating the humic acid solution, DOC removal varied depending on the water type: 27% (3 mg L-1) and 7% (10 mg L-1) in SBW and 7% (3 mg L-1) and 4% (10 mg L-1) in SSW.

Rheology of Decamethylceclopentasiloxane (cyclomethicone) W/O Emulsion System

Choi, Min-Hyung,Jeong, So-Ra,Nam, Sang-In,Shim, Sang-Eun,Chang, Yoon-Ho The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.12

A highly dispersed W/O emulsion of silicone oil (cyclomethicone)/water system was prepared with a nonionic surfactant. The surface and interfacial tension between the oil and water were characterized in terms of the droplet size distribution and viscosity change of the emulsion. When the dispersed phase concentration was relatively high, the viscosity of the emulsion was rapidly increased and the droplet size of the emulsion was decreased. The rheological behavior of the emulsion system showed non-Newtonian and shear thinning phenomena depending upon the content of the dispersed phase. The droplet size of the emulsion was decreased with increasing surfactant content and water concentration. The relative viscosity of the emulsion was better predicted with the Choi-Schowalter model than with the Taylor model. The value of the complex modulus increased with increasing surfactant concentration. The linear viscoelastic region was expanded with a dispersed phase concentration. According to the change in the viscosity, the behavior was classified into three distinct regions: [I] linear viscoelastic, [II] partially viscoelastic, and [III] viscous. The creep/recovery behaviors in each region were characterized.

뮤직비디오 이미지 연구의 출발

최민성 한국언어문화학회 ( 구 한양어문학회 ) 2002 한국언어문화 Vol.22 No.-

Choi Min sung. 2002. The beginning of a study on the music video. This articl attempt to explain significance of study of music video from three point of view. First, we ca research post-modernity of Korea by studying music video. The Western study explain culture peculiarity of post-inderstrial society in music video. However, post-modern peculiarity of Korea is different from the Western because Korea is modernized by distorted way. post-modern peculiarity of Korea is funded out in Korean music video well. Second, we can research image in the capacity of simulacra by studying music video. Music video is primitive genre that it stimulates desire of viewer and forms the studying music video. It is very important that music video makes competitive image in a view of culture contents industrial. We ca find out a solution how will capture the attention of viewers. So, we can confirm that music video is worth studying and the studying of music video solve expansional problem of problem of mass art.

Surface Modification of Block Copolymer Through Sulfur Containing Plasma Treatment

Choi, Sang Wook,Shin, Jae Hee,Jeon, Min Hwan,Mun, Jeong Ho,Kim, Sang Ouk,Yeom, Geun Young,Kim, Kyong Nam American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.10

<P>Some of the important issues of block copolymer (BCP) as an application to the potential low cost next generation lithography are thermal stability and deformation during pattern transfer process in addition to defect density, line edge/width roughness, etc. In this study, sulfur containing plasma treatment was used to modify the BCP and the effects of the plasma on the properties of plasma treated BCP were investigated. The polystyrene hole pattern obtained from polystyrene polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) was initially degraded when the polystyrene hole was annealed at 190 degrees C for 15 min. However, when the hole pattern was treated using sulfur containing plasmas using H2S or SF6 up to 2 min, possibly due to the sulfurization of the polystyrene hole surface, no change in the hole pattern was observed after the annealing even though there is a slight change in hole shapes during the plasma treatment. The optimized plasma treated polystyrene pattern showed the superior characteristics as the mask layer by showing better thermal stability, higher chemical inertness, and higher etch selectivity during plasma etching.</P>

Effects of Supercritical Carbon Dioxide Treatment on Meat Quality and Sensory Evaluation in Soy Sauce and Hot-pepper Paste Marinated Pork

Choi, Young Min,Lee, Sang Hoon,Choe, Jee Hwan,Kim, Kyoung Heon,Rhee, Min Suk,Kim, Byoung Chul Korean Society for Food Science of Animal Resource 2013 한국축산식품학회지 Vol.33 No.5

The objective of this study was to investigate the effects of supercritical carbon dioxide (SC-$CO_2$) treatment on meat quality and sensory evaluation of marinated pork. Meat marinated in two traditional Korean marinades, soy sauce and hot-pepper paste, and raw marinated meat were then treated with 7.4, 12.2, or 15.2 MPa $CO_2$ at $31.1^{\circ}C$for 10 min. The SC-$CO_2$ treatments had no effect on the meat pH (p>0.05) or Warner-Bratzler shear force (p>0.05). There was no significant difference (p>0.05) in the total loss (sum of treatment loss and cooking loss) between the control and SC-$CO_2$ treated samples at 15.2 MPa (soy sauce marinated pork: 21.78 vs. 18.97%; hot-pepper marinated pork: 21.61 vs. 18.01%). After the SC-$CO_2$ treatment, lighter surface colors were observed in the treatment samples compared to those of the control samples (p< 0.001). However, tasting panelists were unable to distinguish a difference in color or in overall acceptability of the control and treatment (p>0.05). In the case of soy sauce marinated pork, when SC-$CO_2$ applied at 15.2 MPa and $31.1^{\circ}C$for 10 min, treatment samples showed a tenderer meat than the control samples. Therefore, the SC-$CO_2$ treatment conditions had no adverse effects on the sensory quality characteristics of the marinated meat products.

담도 및 췌장 악성종양에서의 CAl9-9의 진단적 가치에 대한 평가

명승재,최승목,김은옥,최호순,이성구,김명환,민영일,류진숙 大韓消化器病學會 1995 大韓消化器病學會誌 Vol.27 No.3

Nanogenerators: Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes (Adv. Mater. 19/2010)

Choi, Dukhyun,Choi, Min-Yeol,Choi, Won Mook,Shin, Hyeon-Jin,Park, Hyun-Kyu,Seo, Ju-Seok,Park, Jongbong,Yoon, Seon-Mi,Chae, Seung Jin,Lee, Young Hee,Kim, Sang-Woo,Choi, Jae-Young,Lee, Sang Yoon,Kim, Jo WILEY-VCH Verlag 2010 ADVANCED MATERIALS Vol.22 No.19

<B>Graphic Abstract</B> <P>The cover shows an image of fully rollable transparent nanogenerators synthesized using chemical vapor deposition grown large-scale graphene sheets as transparent electrodes and piezoelectric ZnO nanorod arrays. Sang-Woo Kim, Jae-Young Choi, and co-workers report on p. 2187 the electrical and structural stability of the nanogenerators, with excellent charge scavenging performance under external mechanical loads such as bending and rolling. This study shows that graphene-based nanogenerators are very promising for self-powered rollable transparent device applications. <img src='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content.gif' alt='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content'> </P>

Comparative Infestation of Paragonimus westermani Metacercaria from Crayfish in Endemic Areas

Choi, Dong Wik,Kim, Min Sang,Joo, Chong Yoon 慶北大學校 醫科大學 1983 慶北醫大誌 Vol.24 No.1

慶尙北道내 肺吸蟲 浸潤地 溪谷에서의 가재의 最近 棲息狀과 가재에서의 폐흡충 피낭유충의 最近 寄生狀을 究明코저 1981年 10月부터 1982年 9月까지 6個處(達城郡 嘉昌面 蛇洞, 玉盆洞, 上院洞과 榮豊郡 豊基邑 錦溪, 英陽郡 英陽面 化川 및 靑松郡 府東面 上宣溪谷)를 調査對象溪谷으로 選定하여 調査한 後 1974年 朴 및 崔의 調査 成績과 比較하였다. 6個處의 肺吸蟲 浸潤地에서의 가재의 棲息密度는 1974年의 그 密度에 比하여 顯著히 低下되었으며 가재에서의 폐흡충 피낭유충의 寄生率과 그 寄生程度도 1974年의 成績에 比하여 낮았다. 가재의 體部位別 폐흡충 피낭유충의 寄生狀에 있어서는 1974年에는 가재의 全體部位에서 本피낭유충을 찾아 볼 수 있었는데 比하여 이번 調査에서는 가재의 頭胸部, 아가미 및 肝에서만 찾아볼 수 있었으며 가재 한마리當 폐흡충 피낭유충數도 全浸潤地에서 1974年에 比하여 1982年에는 甚히 적었다. 폐흡충 피낭유충이 寄生하는 가재의 數와 이들 가재에서의 本피낭유충의 數가 1982年에는 너무 적으므로 가재의 크기와 本피낭유충數 및 1974年의 調査成績과의 相關을 求할 수 없었다. 이번 調査 結果 1974年에서 1982年까지의 지난 8年間 폐흡충 浸潤地에서 가재의 棲息密度와 폐흡충 피낭유충이 寄生하는 가재의 數가 急激히 減少되었음을 알았다. In an attempt to determine the recent patterns of population density of the crayfish, Cambaroides similis, and infestation of the crayfish with the metacercaria of Paragonimus westermani in Kyungpook Province, Korea, the crayfish collected in the six endemic areas, Kum-ge, Wha-cheon, Sang-seon, Ju-dong, Ok-bun dong, and Sang-weon dong streams were examined from April, 1981 to September, 1982. The results obtained in 1982 were compared with the data derived from the crayfish collected at the same streams by Park and Choi(1974). The population density of crayfish in the six endemic areas of P. westermani in the present study decreased markedly compared with those in 1974. The infestation rate for the metacercaria of P. westermani in the crayfish examined and the intensity of infestation in the positive crayfish also decreased compared with those reported by Park and Choi(1974). In the 1974 survey, the metacercaria was found in all parts of the crayfish whereas it was found only in the cephalothorax, the gills, and the liver in the present suevey. In the average number of metacercariae perpositive crayfish (M.P.P.C), a pronounced reduction was encountered in all endemic areas between 1974 and 1982. The number of infested crayfish and the metacercaria of P. westermani in infested crayfish in 1982 was so small that it was impossible to analyze the relationship between the number of metacercaria and the length of crayfish and to compare the data between 1974 and 1982. It was found in the present study that the population density of crayfish in the endemic areas and the infestation of the crayfish with the metacercaria of P. westermani has decreased drastically over the eight-year period from 1974 to 1982.