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℃.

모과내 기능성 유용성분 용매추출공정의 최적화

전주영 ( Ju Yeong Jeon ),조인희 ( In Hee Jo ),경현규 ( Hyun Kyu Kyung ),김현아 ( Hyun A Kim ),이창민 ( Chang Min Lee ),최용희 ( Yong Hee Choi ) 한국산업식품공학회 2010 산업 식품공학 Vol.14 No.2

본 연구에서는 모과내의 여러 가지 기능성 유용성분을 효과적으로 추출하기 위해서, 모과나무의 익은 열매로 만든 약재인 모과를 사용 하였다. 모과의 기능성 유용성분용매 추출 공정의 최적 조건을 확립하고자 하였다. 모과를 에탄올에 추출하여 반응표면 분석법으로 모니터링하여 최적 용매 조건을 설정하였다. 중심합성계획법에 따라 시료에 대한 용매비(X1)와 추출온도(X2), 추출시간(X3)을 요인변수로 하고 추출수율(Y1), 총페놀 함량(Y2), 전자공여능(Y3), 갈색도(Y4), 환원당(Y5)을 종속변수로 하여 시행하였다. 실험 결과 추출수율은 추출 온도와 추출 시간에 유의하게 영향을 받음을 알 수 있었다. 안장점에서 추출조건은 시료에 대한 용매비는 26.38mL/g, 추출온도는 72.82oC, 추출시간은 74.86 min에서 최대값을 나타내었다. 총페놀 함량은 용매비와 시간에 영향을 거의 받지 않았고 추출시간에는 영향을 받았으며, 최대값은 20.70mg/mL 로 나타났다. 이때의 추출조건은 시료에 대한 용매비는 22.61mL/g, 추출온도는 84.49oC, 추출시간은 77.25 min으로 나타났다. 전자공여능은 추출온도에 따라 유의하게 영향을 받은 것으로 나타났다. 안장점에서의 추출조건인 시료에 대한 용매비 10.65mL/g, 추출온도 67.78oC, 추출시간 96.75 min에서 추출수율은 94.12%로 예측되었다. 갈색도에 대한 추출조건은 시료에 대한 용매비 23.77mL/g, 추출온도 87.27oC, 추출시간 96.68 min 일 때 안장점이 나타났다. 환원당은 시료에 대한 용매비 26.83mL/g, 추출온도 82.167oC, 추출시간 81.94 min에서 10.55mg/mL로 최대값을 나타내었고 추출시간에 영향을 받았다. In this study, various active functional components in Chinese Quince were extracted by solvent extraction method. A central composit design for optimization was applied to investigate the effects of independent variables such as solvent to sample ratio (X1), extraction temperature (X2), and extraction time (X3) on the soluble solid contents (Y1), total phenols (Y2), electron donating ability (Y3), browning color (Y4) and reducing sugar contents (Y5). It was found that extraction temperature and extraction time were the main effective factors in this extraction process. The maximum soluble solid contents of 35.77% was obtained at 26.38mL/g (X1), 72.82oC (X2) and 74.86 min (X3) in saddle point. Total phenols were rarely affected by solvent ratio and extraction time, but it was affected by extraction temperature. The maximum total phenols of 20.70% was obtained at 22.61mL/g (X1), 84.49oC (X2), 77.25 min (X3) in saddle point. The electron donating ability was affected by extraction time. The maximum electron donating ability of 94.12% was obtained at 10.65mL/g (X1), 67.78oC (X2), 96.75 min (X3) in saddle point. The maximum browning color of 0.32% was obtained at 23.77mL/g (X1), 87.27oC (X2), 96.68 min (X3) in saddle point. The maximum value of reducing sugar content of 10.55% was obtained at 26.83mL/g (X1), 82.167oC (X2), 81.94 min (X3). Reducing sugar content was affected by extraction time.

대장내시경검사의 전처치로서 항콜린제 사용에 관한 연구 : 전향적, 이중맹검법으로

박경남,한동수,이민호,최호순,박준용,손주현,이오영,함준수,전용철,송승찬,기춘석,윤병철,이종희 대한소화기내시경학회 1997 Clinical Endoscopy Vol.17 No.3

Background: Use of antispasmodic medication prior to colonoscopy is controversial but someone believes antispasmodic may improve visualization of colonic mucosa and ease colonoscope insertion. So, we designed a study to assess the effect of premedication with the antispasmodic, hyoscine-N-butyl bromide(Buscopan') on the performance of colonoscopy. Methods: This study was prospective, double blinded, randomized, controlled study, One hundred three consecutive patients were randomized to receive intravenous buscopan lml(n=52) or placebo(n=51) combined with our standard initial medication(me- peridine 50 mg and midazolam 2 mg). Insertion of colonoscopy was timed, and 100 mm visual analogue scales (VAS) were used for asscssing difficulty of procedure, colonic motility, frequency of positional change, frequency of external compression, difficulty of assistance and degree of discomfort experienced by the patients. Results: There were no significant differences of intubation time between buscopan group(mean time, 7.23 min., range 2~15) and placebo group(7.07 min., range 3-25), (p=0.83) and withdrawal time between buscopan group (6.46 min., range 2-22) and placebo group(6.76 min., range 2 25), (p=0.69). Also, there was no significant differences in intubation time between males and females(buscopan; males 7.00 min., females 7.60 min., p=0.34, placebo; males 7.0~5 min., females 7.08 min., p 0.44). The VAS scores checked by endoscopist(p=0.29), assistant(p=0.32) and patient (p=0.15) were not significantly different in both groups. There were no significant differences in intubation time, VAS scores nf endoscopist, assistant, and patients. Conclusion: Premedication with intravenous bu.opan has no advantage on colonoscopy procedure. Use of antispasmodic medication prior to colonoscopy was not considered as recommendable agent.

Casein micelle 의 조성에 관한 연구 : I. Micelle 크기 별에 따른 각 casein 의 구성비율 I. The relative amounts of individual caseins in the different casein micelles

김영교,신동철,전우민 한국낙농학회 1984 韓國酪農學會誌 Vol.6 No.1

本 實驗은 casein miceile의 크기에 따른 각종 casein의 構成成分을 究明하고자 超遠心分離機를 利用하여 casein micelle을 크기 別로 分類하고 DEAE-cellulose column chromatography를 이용하여 각 casein의 構成比率을 조사하였다. 그 結果를 要約하면 다음과 같다. 1. 脫脂乳를 100,000×g에서 각각 30分, 60分, 90分동안, 200,000×g에서 60分동안 遠心分離하였을 때 沈澱되는 casein micelle 量은 45.00%, 61.43%, 80.00% 및 95.00%였으며 沈澱되지 않는 serum casein量은 55.00%, 38.57%, 20.00% 및 5.00%였다. 2. 脫脂乳를 100,000×g에서 時間 差에 따라서 遠心分離하였을 때 각각 沈澱되는 casein micelle量은 10分間에는 全 casein量의 23.13%, 11∼30分間에는 30.26%, 31∼60分間에는 28.11%였으며, 60分問의 遠心分離에 의해서 沈澱되지 않는 serum casein은 17.79%였다. 3. 時問 差로 遠心分離하여 얻어진 casein micelle중 각 casein의 構成比率을 測定한 結果, α_s-casein, β-casein, κ-casein 및 γ-casein의 상대적인 量은 100,000×g, 10分의 pellet에서 각각 54%, 29%, 11% 및 6%였고, 100,000×g, 11∼30分의 pellet에서는 각각 54%, 28%, 13% 및 5%였고, 100,000×g, 31∼60分의 pellet에서는 각각 51%, 28%, 16% 및 5%로 나타났으며, serum casein은 44%, 29%, 19% 및 8%로 각각 나타났다. This experiment was carried out to study on the protein composition of casein micelles. Three micellar casein pellets and a serum casein were isolated at diferent time of ultracen trifugation. And the composition of individual caseins for the fractions was determined by DEAE-cellulose column chromatography. The results are summarized as follows: 1. When skimmilk was centrifuged for 30 min, 60 min and 90 min at 100,000g and for 60 min at 200,000g, the values for the sedimented casein micelles were 45.00%, 61.43%, 80.00% and 95.00% respectively and that of serum casein was 55.00%, 38.57%, 20.00% and 5.00% respectively. 2. When skimmilk was centrifuged for different time at 100,000g, the values for the sedimented casein micelles were 23.18% for 10 min.(pellet 1), 30.26% from 11 to 30 min.(pellet 2), 28.11% from 31 to 60 min.(pellet 3) and that of serum casein which was not sedimented at 60 min was 17.79% of the total casin. 3. The relative amounts of α_s-, β-, k- and γ-caseins in casein micelles obtained after different time of centrifugation were 54%, 29%, 11% and 8% in pellet 1, 54%, 28%, 13% and 5% in pellet 2, 51%, 28%, 16% and 5% in pellet 3,44%, 29%, 19% and 8% in serum casein respectively.

Variation of Harbor Oscillations in Yeongil Bay

Min­Su Jeon,Joong­Woo Lee,Jae­Hyun Jeong,Sang­Yong Yang,Young­Hwan Jeong 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

  Today, harbor oscillation problems are the most significant factor to consider when designing harbors serving very large ships. In coastal harbors, large vessels moored in the elastic hawsers are often displaced due to the resonance between long period waves and mooring systems. As a result, cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes extreme. The most significant harbor confronted with harbor oscillation problem in Korea is Pohang New port. Many cases of problems are being reported by the pilot association and the local office of MOMAF (Ministry of Maritime Affairs and Fisheries). However, it is difficult to prevent the arrival of long waves causing oscillation within this harbor. Moreover, the Korean government has already started a new port plan at the mouth of Yeongil Bay without addressing the problems that have occurred in Pohang New port. This study deals with the variation of harbor oscillation due to the construction of a 4.1 km breakwater at the bay mouth including the arrangement of the new berths. Numerical methods used are in fairly standard form from the extended mile slope equation. The obtained numerical results were compared with field measurement from the previous and this will bring a certain level of discussion and consideration of variation to the future port development.

Effects of a Portable Computerized Cognitive Training System on the Visual-perceptual Function of Stroke Patients with Mild Cognitive Impairment : A Pilot Study

Min-Jae Jeon(전민재),Jong-Hoon Moon(문종훈) 한국엔터테인먼트산업학회 2019 한국엔터테인먼트산업학회논문지 Vol.13 No.8

본 연구는 휴대용 전산화 인지훈련 시스템이 경도 인지손상이 있는 뇌졸중 환자의 시지각에 미치는 효과를 알고자 하였다. 재활병원에 입원 중인 경도인지 손상이 있는 12명의 뇌졸중 환자가 본 연구에 참여하였다. 모든 대상자들은 실험군과 대조군으로 6명씩 할당되었다. 모든 대상자들은 실험군 또는 대조군의 훈련을 하루 30분, 주 5회, 4주 동안 수행하였다. 실험군은 휴대용 전산화 인지훈련 시스템을 실시하였으며, 대조군은 보편적인 인지훈련을 수행하였다. 시지각을 측정하기 위하여, MVPT-3(Motor-Free Visual Perception-3)을 측정하였다. 연구 결과, 두 군은 중재 전과 후로 MVPT-3 total score에서 유의한 향상을 보였다(p<.05). 두 군 간 변화량 비교에서 실험군은 대조군보다 MVPT-3 total score와 visual short-term memory of sub-item of MVPT-3에서 유의하게 더 큰 향상을 보였다(p<.05). 이러한 결과는 휴대용 전산화 인지훈련 시스템이 경도인지손상이 있는 뇌졸중 환자의 시지각 능력 향상에 긍정적인 효과를 이끌어 낼 수 있는 중재방법이 될 수 있음을 시사한다. This pilot study investigated the effects of a portable computerized cognitive training system on the visual-perceptual function of stroke patients with mild cognitive impairment. Subjects were twelve stroke patients with mild cognitive impairment, who were assigned to an experimental group (n=6) or a control group (n=6). All subjects were trained in their respective groups for 30 min/day, five times a week, for four weeks. In each session, the experimental group received a portable computerized cognitive training program, and the control group received conventional cognitive training. The Motor-Free Visual Perception-3 (MVPT-3) was used to measure subjects’ visual-perceptual ability. The MVPT-3 total scores for both groups significantly improved after the intervention (p<.05). The total score on the MVPT-3 and the score on the visual short-term memory subcategory of the MVPT-3 significantly improved for the experimental group compared to the control group (p<.05). These findings suggest that the portable computerized cognitive training system might be effective to improve the visual-perceptual function of stroke patients with mild cognitive impairment.

Preliminary Study on Chlorination Reaction of Lithium Carbonate for Carbon-Anode-Based Oxide Reduction Applications

Jeon, Min Ku,Kim, Sung-Wook,Choi, Eun-Young Korean Radioactive Waste Society 2021 방사성폐기물학회지 Vol.19 No.2

The reaction between Li₂CO₃ and Cl₂ was investigated to verify its occurrence during a carbon-anode-based oxide reduction (OR) process. The reaction temperature was identified as a key factor that determines the reaction rate and maximum conversion ratio. It was found that the reaction should be conducted at or above 500℃ to convert more than 90% of the Li₂CO₃ to LiCl. Experiments conducted at various total flow rate (Q) / initial sample weight (W_i) ratios revealed that the reaction rate was controlled by the Cl₂ mass transfer under the experimental conditions adopted in this work. A linear increase in the progress of reaction with an increase in Cl₂ partial pressure (pCl₂) was observed in the pCl₂ region of 2.03-10.1 kPa for a constant Q of 100 mL·min^-1 and W_i of 1.00 g. The results of this study indicate that the reaction between Li₂CO₃ and Cl₂ is fast at 650℃ and the reaction is feasible during the OR process.

이산화티타늄계 광촉매를 이용한 톨루엔의 처리 특성

전의찬,송민종,김전희 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

각종 급ㆍ만성의 건강장해를 일으킬 뿐만 아니라, 광화학 반응에 의해 오존을 형성하는 것으로 알려진 휘발성유기화합물 중 대표적인 물질인 톨루엔을 광촉매산화법으로 처리할 경우 최적 처리조건을 분석하고자 광촉매의 결정구조, 광원의 세기, 전자수용체로서 산소의 유무 등에 따른 톨루엔의 처리효율을 분석하였다. 실험결과 루틸령 결정구조에 비해 아나타제형 결정구조를 갖는 이산화티타늄의 톨루엔 처리효율이 높게 나타났으며, 광원의 세기가 높을수록 전자수용체로서 산소가 존재할 경우 높은 처리효율을 나타내었다. 시간과 공간적인 제약으로 물, 오존 그리고 증기와 같은 다양한 전자수용체가 존재할 경우의 톨루엔의 처리효율을 파악하지 못하였으며, 온도, 습도 및 촉매활성에 영향을 주는 여러 가지 인자들을 대상으로 그것들의 변화에 따른 처리효율의 고찰을 못하였다. 앞으로 보다 효율적인 이산화티타늄계 광촉매의 제조방법 개발과 이산화티타늄계 광촉매를 이용한 다양한 VOC 처리방법의 개발이 요구된다. An available methods for abating VOC(including Toluene) are thermal or catalytic incineration, liquid absorption, solid adsorption, condensing, membranes, biodegradation and plasma discharge, but a number of defects are these VOC abating methods, including ; requires a auxiliary fuel, generate secondary pollutants(waste catalysts, waste absorbents, waste adsorbents, ozone, etc.), a large scale, etc.. But photoactive catalysts, when illuminated with UV-light, generate highly reactive radicals that can oxidize the organic contaminants in gas. One methods to increase the efficiency of the process, and thereby reduce the light energy requirement, is by developing more active catalysts. Because of, ball type TiO2 catalyst were obtained commercially and/or prepared in laboratory were examined for their photoacivity, and they are TiO2 added some annex(Al203, SiO2, KsO, P205, etc.). The organic compounds used to identify the best photocatalysis condition were toluene. This study also examined the impact of catalyst structure, light intensity, existence of oxygen as an electron acceptor and Toluene initial concentration on the reaction kinetics. Labratory experiments were performed to investigate TiO2 photocataysis for treating test gas contaminated with Toluene. and TiO2 photocatalysis efficiency for mineralization of Toluene is also evaluated. The photooxidation of Toluene was carried out in a photocatalytic reactor at room temperature. I performed Toluene photocatalytic oxidation experiments using a single-pass annular reactor. The organic-contaminated gas was prepared in teflon sampling bag(25L) and passing through photocatalytic reactor by vacuum pump which is located reactor outlet. The Toluene diluted with mixture air or nitrogen gas. Flow rates for test gas stream were controlled by micro flow meter going out the reactor. The reactor illuminated with 15W near-UV lamp, BLB lamp or Fluorescent lamp. The light intensity at the catalyst surface were estimated to be 0.8 to 6㎽ ㎝-2s-1. The inner cell of the reactor was packed with ball type titanium dioxide(φ 6㎜). Toluene was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor outlet by gas-tight syringe. TiO2 photocataysis for treating test gas contaminated with Toluene. and TiO2 photocatalysis efficiency for mineralization of Toluene is also evaluated. Using the anatase type photocatalyst, Touene conversion rate is greater than that of rutile(86.1% conversion of 100ppmv Toluene using anatase type photocatalyst, 78% conversion of 100ppmv Touene using rutile type photocatalyst at 0.5L/min) Effect of light intensity on the rate of Toluene photocatalytic decomposition was investigated by three type lamps within the reactor. When light intensity to increase, the Toluene conversion rate to increase. Using the BLB lamp showed higher activity than the Fluorescent lamp, but UV lamp showed the hight photocatalytic activity(19.1% conversion of 100ppmv Toluene with Fluorescent lamp, 60.4% conversion of 100ppmv Toluene with BLB lamp, 86.1% conversion of 100ppmv Toluene with UV lamp at 0.5L/min). Experiments with added oxygen as an electron acceptor improved the reaction rate considerably(86.1% conversion of 100ppmv Toluene without oxygen, 62.5% conversion of same Toluene concentration with mixture air at 0.5L/min).

Evaluation of High Power Light Emitting Diodes (HPLEDs) as Potential Attractants for Adult Spodoptera exigua (Hübner)

Min-Seok Oh,Sang-Guei Lee,Ju-Hyun Jeon,Hoi-Seon Lee 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.10

To response evaluation of high power light emitting diodes (HPLEDs) as potential attractants to the Spodoptera exigua adults, we investigated the attractiveness of specific wavelength, illuminance intensity and light-exposure time, and compared them to the fluorescent. The all light treatments with the 40 lux intensity attracted the significantly highest number of S. exigua. The optimal light-exposure time exhibited the highest attraction rate at the 60 min. When the attraction and repellent rate in the optimal conditions to the S. exigua was surveyed, the white HPLED exhibited the highest attraction rate (91.1%), whereas the red HPLED exhibited the most repellent rate (33.3%). When evatuated of illuminance efficiency with fluorescent as control, white and red HPLED were found to be 9.14 and 10.34 times more efficient than fluorescent. These data clearly show that both the 40 lux intensity and the 60 min light-exposure time by using the white HPLED was the most suitable for attraction of the S. exigua.