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℃.

실험적 급성 허혈성 신부전에서 Verapamil 이 혈중 Polyamine 동태에 미치는 영향

원동준(Dong Jun Won),권현민(Hyun Min Kwon),김용섭(Yong Seop Kim),구자룡(Ja Ryong Gu),권영주(Young Ju Kwon),조원용(Won Yong Cho),김형규(Hyung Kyu Kim) 대한내과학회 1991 대한내과학회지 Vol.40 No.6

N/A It has been proposd that calcium entry from an external medium increases intracellular free calcium to toxic levels during ischemic acute renal failure, and verapamil (ARF) has been suggested as the agentblocking calicium entry into renal cells and protecting renal function during ischemic injury. Polyamines, anorganic cations that play various roles in normal cellular proliferation and differentiation, accumulate in renal failare. Alsa it has been suggested tht the synthesis and metabolism of polyamine are influence by acute changes of the general condition, such as acute renal failure, and are mediated by a calcium influx into the cells. The study was designed to study the protective effects of systemic verapamil pretreatment on renal function and the influence on polyamine metabolism in experimental ischemic ARF in cats. For these purpose, the experimental animals were divided into 2 groups. While Group I (n=5) was an ischemic ARF model by renal artery clamping for 60 minutes, Group II (n=5) was ischemic ARF with systemic verapamil (5 ml/min/kg) pretreatment. The creatinine clearance and plasma and urinary polyamine were measured in each group before and after the renal artery clamp. The results were as follows: 1) Creatinine clearance before and after the renal artery clamp were 10.64±7.18 ml/min/kg and 2.09±1. 70 ml/min/kg in Group I, 4.47±3.38 ml min/kg and 0.60±0.79ml/min/kg in Group II, respectively, So creatinine clearance decreased more significantly in Group II campared with Group I. 2) Plasma polyamine increased after ischemia in Group I. In group I, plasma levels of putrescine, spermidine, and spermine before ischemia were 4.75±0.40 nmol/ml, 0.69±0.09 nmol/ml, and 0.83±0.63 nmol/ml, were elevated to 7.17±2.91 nmol/ml, 9.83±1.46 nmol/ ml, and 2.64±1.14nmol/ml after ischemia. But in Group II, the plasma level of polyamine was not changed, and especially, spermine decreased significantly from 0.83±0.27 before ischemia to 0.49±0.23 nmol/ml after ischenmine (p=0.033). 3) Urine polyamine excretion decreased after ischemia in Group I and Group II. In Group II, urinary excretion of spermidine and spermine before ischemia, 0.13±0.10 nmol/min and 0.17±0.13nmol/min, decreased after ischemia to 0.01±0.01nmol/min (p=0.019) and 0.032±0.26 nmol/min (p=0.0257). 4) In renal tissue, spermine content vas highest. In Group II, preischemic spermine were 397.20 nmol/g and increased to 646.66nmol/g after ischema, But there were no significant changes in the polyamine contents in Group II. From these data, it was suggested that systemic verapamil pretreatment exerts no protective effect on ischemic ARF. Plasma polyamines are elevated in ischemic ARF, and verapamil may protect these elevations.

대추 아임계수 추출물의 폴리페놀 함량 및 산화방지 평가

고민정(Min-Jung Ko),권미리(Mi-Ri Kwon),정명수(Myong-Soo Chung) 한국식품과학회 2021 한국식품과학회지 Vol.53 No.3

아임계수 추출 기술을 이용하여 대추 추출물을 얻고 총 페놀 함량, DPPH 라디칼 소거능과 ABTS 라디칼 소거능을 이용하여 추출조건에 따른 페놀 성분 함량 변화 및 산화 방지효과를 확인하였다. 아임계수 추출물은 총 페놀 함량, DPPH라디칼 소거능, ABTS 라디칼 소거능의 결과 값이 모두 메탄올 및 에탄올을 이용하여 추출한 결과 보다 우수하게 나타났다. 아임계수 추출법은 메탄올 및 에탄올을 이용하여 추출하는 방법 보다 추출 시간도 20분 이내로 짧았고, 유기용매를 사용하지 않고 친환경적으로 추출할 수 있었다. 아임계수 추출물의 총 페놀 함량과 산화방지 효과의 결과는 높은 상관관계를 보였는데, 항산화 효과가 있는 페놀류가 많이 추출될수록 산화방지 효과도 우수하게 나타났다. 본 연구를 통해, 아임계수 추출 방법은 오직 물을 사용하여 유효성분을 추출하는 친환경적이고 안전한 신가공기술이며 잠재성과 우수성을 확인하였다. 아임계수 추출기술은 앞으로도 다양한 유효성분추출 및 소재 가공으로 식품 산업에 응용하여 사용될 수 있을 것이다. Subcritical water extraction (SWE) is an eco-friendly extraction method that uses only purified water as a solvent under high temperature and high pressure conditions. In this study, total phenolics, and antioxidant activity were evaluated in Ziziphus jujuba Mill extracts from subcritical water obtained by varying the extraction temperature (110-190℃) and extraction time (1-20 min). Total phenolics was maximized with extraction at 190℃ for 15 min (67.79±3.45 mg gallic acid equivalent/g jujube). The 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (48.84±4.74%) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging activity (84.75±1.15%) were maximal at extraction conditions of 190℃, for 20 min. All jujube extracts prepared using SWE had higher total phenolics and antioxidant activities than extracts prepared using organic solvent extraction (60℃, 120 min), including methanol and ethanol. SWE could be an excellent alternative to organic solvents for extracting phenolics and antioxidant compounds.

C -11 및 F - 18 표지 콜린의 합성과 체내동태에 관한 연구

전권수,유국현,김상욱,임상무,홍성운,서용섭,양승대,안순혁,허민구 대한핵의학회 2001 핵의학 분자영상 Vol.35 No.3

Objectives: Recently, [methyl-(11)^C]-(β-Hydroxyethyl)trimethylammonium ([(11)^C]choline) has been discovered to be a very effective tracer in imaging various human tumors using positron emission tomography. Because of the short half-life of C-11, it is very difficult to use in a routine imaging procedure and needs a frequent synthesis of [(11)^]choline. This can be supplemented by the substitution of [(11)^Ccholine with [methyS-18]fluorocholine. Here, we would like to report cell uptake and biodistribution of [(11)^Ccholine and [(18)^F]fluorocholine as a basic study. Methods [(11)^C]Choline was prepared by the treatment of [(11)^C]CHzI with N,N-dimethylaminoethanol and [18F]fluorocholine was synthesized from reaction of CHzBr[18F]F with N,N-dimethylaminoethanol. The radiochemical purity was checked by high performance liquid chromatography (HPLC). The biodistribution of [(11)^C]choline and [(18)^F]fluorocholine was determined in balb/c mouse at 5 min, 20 min, 40 min and 80 min. The cell uptake wa measured using glioma (9L) and colon adeocarcinoma (SW620). Results: The radiochemical purity was more than 98% after purification. In the liver, uptake did not change over time the uptake was 20/ID/g for [C]choline and 13%ID/g for [(18)^F]fluorocholine. In the kidney, radioactivity decreased over tirne the uptake was 15%1D/g for [(11)^Ccholine and 20%ID/g for [(18)^F]fluorocholine, 80 min post-injection. The cell uptake of [(11)^Ccholine was 4.93% for glioma (9L) and 18.69F for colon adenocarcinoma (SW620). For [(18)^F]fluorocholine, 1.77% for glioma (9L) and 2.77% for colon adenocarcinoma (SW620). Conclusion: [(11)^CCholine and [(18)^F]fluorocholine showed a different cell uptake tendency, depending on cancer cell line. (Korean J Nucl Med 200135:185-191)

중학생들의 인터넷 중독 위험수준에 따른 신체활동량과 비만도의 관련성

정민기(Jeong, Min-Ki),김권민(Kim, Gwon-Min),권유찬(Kwon, Yoo-Chan) 한국체육과학회 2015 한국체육과학회지 Vol.24 No.4

The purpose of this study was to examine the association perceived physical activity pattern and body mass index according to habitual internet usage among middle school student. Data were analyzed for 969 students who responded to self-reported base cross-sectional survey relating to socio-demographic variables, internet usage status, and a short version of the international physical activity questionnaire. Prevalence rate of physical activity status showed that 53.5% at 150 min/week under, 46.5% at 150min/week over. Prevalence rate of internet usage showed that 95.6% at normal group, 2.6% at potential group, 1,9% at addiction group. Prevalence rate of body mass index status of over weight according to internet usage status shoed that 83.1% at normal, 5.1% at potential, 11.9% at addiction. Prevalence rate of physical activity levels of 150 min/week under according to internet usage status showed that 93.8% at normal, 3.5% at potential, 2.7% at addiction. In comparison with the physical activity levels was significantly more likely potential internet usage (OR, 2.62; 95% confidence interval [95%CI], 1.09-6.47; p〈.05) and addiction usage (OR, 3.82; 95% confidence interval [95%CI], 1.24-11.75; p〈.05). The results revealed that physical activity levels and body mass index correlates of internet usage status. This finding suggest the necessity of developing specific strategies for physical activity intervention by internet addiction among middle school students.

Feasibility of Calibrating Smartphone to Access Physical Activity

이정민(Jung Min Lee),김영원(Young Won Kim),권이석(Yi Suk Kwon),Timothy R. Derrick,Gregory J. Welk 한국체육측정평가학회 2015 한국체육측정평가학회지 Vol.17 No.3

대부분의 신체활동측정을 위해 연구들은 가속도계를 이용하여 측정되어져 왔다. 하지만, 스마트폰이 대중화 되면서스마트폰에 내장된 가속도계를 이용하여 신체활동을 측정 할 수 있는 에플리케이션들이 빈도 높게 늘어나고 있다. 따라서 이 연구에서는 스마트폰에 내장되어 있는 가속도계를 이용하여 에너지 소비량을 구하는 공식을 만들고 그 공식을 현재 연구중심으로 많이 사용되는 가속계와 비교하고 교차분석을 통하여 정확성과 실용성을 검증하는 것이다. 이러한 목적을 달성하기 위하여 건강한 성인 44명을 편의추출 하여 가속계와 스마트폰을 착용시켜 69분 동안 다양한 일상생활 활동을 시켰으며 신체활동 측정의 준거검사인 간접열량계(Oxycon Mobile)가 사용되었다. 회귀분석을 통하여 만들어진 연산은 교차 타탕도 분석을 통하여 정확도를 검증하였고 검사도구의 정확성은 절대오차율(%)을 계산하고 검사도구간 상관계수 (r), Bland-Altman plot 과 equivalence testing 사용하여 검증하였다. 연구결과에 의하면 스마트폰을 통해 얻어진 절대오차율은 (42.4%)를 보였고 Freedson`s 기준치와 비교했을 때는 (38.2%)를 보였다. 그러나 스마트폰을 통해 만들어진 연산은 걷기 와 달리기의 에너지 소비량은 측정하는데 유의하다는 결과가 나왔다. 추후, 스마트폰만을 이용한 신체활동 측정이 다양하게 필요하고 그 정확성을 검증하는 연구들도 필수적으로 요구된다. The purpose of the study was to develop algorithms to predict energy expenditure (EE) and to evaluate their utility compared to existing accelerometer technology. Forty-four participants wore an Actigraph GT3X (AG3X) and the Samsung Galaxy S2 Smartphone (SP) over a 69 min period. Oxygen consumption (VO<sub>2</sub>) was simultaneously measured by a portable indirect calorimetry system. EE prediction equations for the SP were developed from the walking and running activities using standard regression methods. The equation was then cross-validated on a separate holdout sample (n=22) using equivalence testing to evaluate accuracy. The overall mean absolute percentage errors were large for both the SP algorithm (42.4%) and the Freedson`s AG3X algorithm (38.2%). However, the estimated METs from the SP was statistically equivalent to the measured METs for the two activities used in calibration: walking (90% CI: 2.85, 3.50 kcal·min-1) and running (90% CI: 7.64, 8.25 kcal·min-1). Other activities were not accurately assessed with the SP but none of the estimates from the AG3X met the statistical criteria for equivalency. The study demonstrates that data from SP can be easily calibrated to estimate EE and that accuracy is comparable to the common research-grade monitors.

비만학생들의 운동후 회복시 초과 산소소비량 및 지속시간에 관한 연구

박철호,권민호,고봉민,박은경,우상헌 東亞大學校附設스포츠科學硏究所 1999 스포츠科學硏究論文集 Vol.17 No.-

The purpose of this study was to examine the effect of two different intensity of continuous exercise on magnitude of excess post-exercise oxygen consumption(EPOC), energy consumption following a 20min treadmill exercise. The subjects of this study were eight super-obesity in middle school students who were above 13 years old. subjects participated in two different exercise intensity to measure respiratory gas, blood lactate concentration and eardrum temperature. The results of this study were as follows: 1. The Energy consumption of the high intensity (80% VO₂ max) exercise group (264.68 35.60cal) was greater than that of the low intensity (50%) exercise group(172.01 20.39 Cal)(p<.001). 2. The EPOC of the high intensity exercise group (22.36+ 6.82Cal ) was greater than that of the low intensity exercise group(15.39+5.27 Cal)(p<.001). 3. The EPOC duration of th high intensity exercise group(28.36=3.56min) was longer than that of the low intensity exercise group(17.23+1.25min)(p<.001) 4. The blood lactate concentration, respiratory exchange ratio and temperature of the high intensity exercise group were greater than those of the low intensity exercise group(p<.05,p<.01). EPOC and duration were increase with 80%VO₂max, 80% VO₂max as intensity exercise got higher this also showed that it had something to do with lactate concentration in blood and increase of body temperature in the conclusion. We considered that there was a difference in using methods of energy, as there was a similar difference in RER. We though this following with oxygen consumption after exercise, we could clarify that high intensity exercise was better than lower intensity exercise in sametime for those who are obese especially adolescents to maintain their weights on the aspect of effect.

대학생들의 인터넷 사용정도에 따른 신체활동량과 신체구성의 관련성

김권민(Kim, Gwon-Min),박상갑(Park, Sang-Kab),권유찬(Kwon, Yoo-Chan) 한국체육과학회 2015 한국체육과학회지 Vol.24 No.3

The purpose of this study was to examine the association perceived physical activity patten and body composition according to habitual internet usage among university students. Data were analyzed for 500 students who responded to an self-reported based cross-sectional survey relating to socio-demographic variables, internet usage status, and a long version of the international physical activity questionnaire. Prevalence rate of physical activity status showed that 40.2% at 150 min/week over, 59.8% at 150 min/week under. Prevalence rate of internet usage showed that 94.6% at normal group, 3.0% at potential, 2.4% at addiction. Prevalence rate of physical activity levels of 150 min/week under according to internet usage status showed that 92.0% at normal, 4.3% at potential, 3.7% at addiction. In comparison with the physical activity levels was significantly more likely potential internet usage (OR, 4.82; 95% confidence Interval [95%CI], 1.07, 21.86; p〈.05) and addiction usage (OR, 8.00; 95% confidence interval [95%CI], 1.02, 62.56; p〈.05) The results revealed that physical activity levels correlates of internet usage status. This findings suggests the necessity of developing specific strategies for physical activity intervention by internet addiction among university students.

금불초 종(種) 및 개화시기에 따른 금불초 꽃 추출물의 항산화 효능

권순식 ( Soon Sik Kwon ),전소하 ( So Ha Jeon ),전지민 ( Ji Min Jeon ),천종우 ( Jong Woo Cheon ),박수남 ( Soo Nam Park ) 대한화장품학회 2013 대한화장품학회지 Vol.39 No.3

본 연구에서는 금불초(Inula britannica) 종(種) 및 개화시기에 따른 금불초 추출물의 항산화 효능을 알아보았다. 이들 추출물의 free radical 소거활성을 살펴본 결과, 만개한 금불초 꽃(I. britannica var. chinensis) 추출물의 경우 500 μg/mL의 농도에서 79.89%의 free radical 소거활성을 보였으나, 금불초 유사종인 가는 금불초(I. britannica var. linariaefolia Regel), 가지 금불초(I. britannica var. ramosa) 및 버들 금불초(I. salicina var. asiatica)의 꽃 추출물의 경우 free radical 소거활성이 거의 나타나지 않았다. 또한 꽃이 만개하였을 경우 꽃 추출물 분획에서는 93.62%의 free radical 소거활성을 보였으며, 봉우리 추출물 분획은 43.28%, 낙화추출물 분획은 14.11%를 나타냈다. 금불초의 종 및 개화시기를 선정 후, 추출용매, 온도, 시간을 조절하여 최적의 추출조건을 확립하였다. 그 결과, 65 ℃ 에탄올 추출물에서 가장 높은 DPPH free radical 소거활성이 나타났으며, 시간에 따른 유의적 차이는 없는 것으로 나타났다. 만개한 금불초 꽃 추출물에 대하여 rose-bengal로 증감된 사람 적혈구의 광용혈 실험에서 세포보호효과를 측정한 결과, 5 ~ 50 μg/mL의 범위에서 농도 의존적으로 세포 보호 효과를 나타내었다. 특히 50 μg/mL의 농도에서 τ50이 116.1 min으로 비교물질인 (+)-α-tocopherol에 비해 1.58배 더 큰 세포 보호활성이 있음을 알 수 있었다. HPLC로 금불초 꽃 추출물을 분석한 결과 flavonoid의 일종인 quercetin이 다량 함유되어 있는 것을 확인하였다. 이상의 결과들은, 65 ℃ 에탄올로 추출한 만개한 금불초 꽃 추출물의 경우 다량의 quercetin을 함유하며, 그로 인하여 free radical 소거활성 및 ROS에 대항하여 세포막을 효과적으로 보호함으로써 태양 자외선에 노출된 피부를 보호하는 항산화제로서 작용할 수 있을 것으로 사료되며, 기능성 화장품 원료로서 응용 가능성이 있음을 시사한다. In this study, antioxidative effects of the extracts of different species and flowering periods of Inula britannica were investigated. According to the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of the extracts, The I. britannica var. chinensis flower extract (500 μg/mL) was measured in a 79.89% free radical scavenging activity, but the flower extracts of similar species (I. britannica var. linariaefolia Regel, I. britannica var. ramosa, I. salicina var. asiatica) did not show any effect on the free radical scavenging activity. The effects of the free radical scavenging activity of I. britannica var. chinensis flower extracts were exhibited in the order of full bloom (93.68%), bud (43.28%), and fallen blossom (14.11%). Next, we established optimum condition of extract solvent, temperature, extraction time. The extract from ethanol at 60 ℃ showed the most free radical scavenging activity among other conditions and extraction time not relevant in free radical scavenging activity. The protective effects of the extract of I. britannica var. chinensis flower on the photohemolysis of human erythrocytes by using rose bengal were increased in a concentration-dependent manner (5 ∼ 50 μg/mL). In particular, the extract in 50 μg/mL concentration exhibited better protective activity (τ₅₀ = 116.1 min) than (+)-α-tocopherol (τ₅₀ = 73.44 min), which is a known lipophilic antioxidant. Principle component of I. britannica var. chinensis flower was identified as quercetin of flavonoids by high-performance liquid chromatography (HPLC). These results indicate that the extract of I. britannica var. chinensis flower can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging free radical and ¹O₂, and protect cellular membranes against ROS. It is concluded that the antioxidative effects of the extract of I. britannica var. chinensis flower could be applicable to functional cosmetics.

습식텍스쳐를 이용한 단결정 실리콘 광학적 · 전기적 특성 연구

한규민(Han Kyu-min),유진수(Yoo Jin-su),유권종(Yoo Kwon-jong),이희덕(Lee Hi-deok),최성진(Choi Sung-jin),권준영(Kwon Jun-young),이준신(Yi Jun-sin) 한국태양에너지학회 2010 한국태양에너지학회 학술대회논문집 Vol.2010 No.4

The presence of ultrasonic wave in caustic cleaning process enhances the remove pollutants, and more homogeneous, textured structure. The silicon wafers, cleaning in Deconex OF 145 solution (0.5~2wt %) with DIW under ultrasonic environment for 5 min. The presence of uniform thin layer of SiO2 on c-Si surface enhances etching rate in the caustic etching mixture solution of NaOH (1.5 wt %), DI water and IPA (6 wt %) at 90℃ for 20 min and results in a fine, more homogeneous and small textured structure.