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℃.

Effect of spark plasma sintering conditions on the thermoelectric properties of (Bi_0.25Sb_0.75)₂Te₃ alloys

Lim, Sang-Soon,Kim, Ju-Heon,Kwon, Beomjin,Kim, Seong Keun,Park, Hyung-Ho,Lee, Ki-Suk,Baik, Jeong Min,Choi, Won Jun,Kim, Dong-Ik,Hyun, Dow-Bin,Kim, Jin-Sang,Baek, Seung-Hyub Elsevier 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.678 No.-

<P><B>Abstract</B></P> <P>As a field-assisted technique, spark plasma sintering (SPS) enables densification of specimens in a very short period of time compared to other sintering techniques. For high performance thermoelectric material synthesis, SPS is widely used to fabricate nanograin-structured thermoelectric materials by rapidly densifying the nanopowders suppressing grain growth. However, the microstructural evolution behavior of thermoelectric materials by SPS, another important process during sintering, has been rarely studied. Here, we explore SPS as a tool to control the microstructure by long-time SPS. Using p-type (Bi<SUB>0.25</SUB>Sb<SUB>0.75</SUB>)<SUB>2</SUB>Te<SUB>3</SUB> thermoelectric materials as a model system, we systematically vary SPS temperature and time to understand the correlations between SPS conditions, microstructural evolution, and the thermoelectric properties. Our results show that the relatively low eutectic temperature (∼420 °C) and the existence of volatile tellurium (Te) are critical factors to determine both microstructure and thermoelectric property. In the liquid-phase sintering regime, rapid evaporation of Te leads to a strong dependence of thermoelectric property on SPS time. On the other hand, in the solid-phase sintering regime, there is a weak dependence on SPS time. The optimum thermoelectric figure-of-merit (Z) of 2.93 × 10<SUP>−3</SUP>/K is achieved by SPS at 500 °C for 30 min. Our results will provide an insight on the optimization of SPS conditions for materials containing volatile elements with low eutectic temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spark plasma sintering (SPS) is used to synthesize the thermoelectric (Bi<SUB>0.25</SUB>Sb<SUB>0.75</SUB>)<SUB>2</SUB>Te<SUB>3</SUB>. </LI> <LI> Liquid phase and volatile element are a key for the microstructure and thermoelectric property. </LI> <LI> Thermoelectric figure-of-merit of 2.9 × 10<SUP>−3</SUP>/K is achieved at 500 °C for 30 min. </LI> </UL> </P>

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)

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.

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.

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.

허혈성 심질환에 있어서 아데노신 급속 정맥투여후 관동맥압의 변화에 관한 연구

봉종대,오종용,배성한,신원용,김철현,이광희,최태명,현민수,김성구,권영주 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.2

Background: Adenosine interacts with A1 receptors present on the extracellular surface of cardiac cells, activating K+channels in a fashion. It produces coronary vasodilatation and AV nodal block. The half-time is one to six second and has ultra-short action. In ischemic heart disease, fractional flow reserve(FFR) can be achieved safely with intravenous adenosine infusions at a rate of 150㎍/kg/min which cause maximal coronary hyperemia. Purpose: We investigated the patients who have had ischemic heart disease(n=8). After adenosine intravenous administration(150㎍/kg/min), the effect cause maximal hyperemia of coronary artery. During peak maximal hyperemia, we reported clinical findings, coronary hemodynamics and electrocardiogram findings. Methods: After diagnostic coronary angiography and left ventriculography, catheter was advanced into the ostium of coronary artery. We investigated coronary hemodynamics such as systolic coronary artery pressure, diastolic coronary artery pressure, mean coronary artery pressure and heart rate. To assess the use of adenosine for determination of fractional flow reserve, hemodynamics and electrocardiogram were measured at basal state and during peak maximal hyperemia. Results: Symptoms developed 1.5-2 minute after adenosine intravenous administration and each symptom disappeared 2-2.5 minute after adenosine administration. Two patients represented asymptomatic appearance and six patients complained of flushing, chest pain, palpitation and headache. In eight patients with ischemic heart disease, 1.5 minute after venous administration of 150㎍/kg/min of adenosine, coronary artery pressure decreased and heart rate increased significantly. Conduction abnormalities after administration of 150㎍/kg/min of adenosine were transient 2nd degree AV block 2 cases(25%). Conclusions: Adenosine is a potent ultra short-acting vasodilator. Although coronary artery pressure decreased and heart rate increased and mild cardiovascular symptoms occurred after continuous infusion of 150㎍/kg/min of adenosine, it is useful as an agent for determination of fractional flow reserve.

밀링 에너지 변화에 따른 TiC 분말의 미세화 거동에 관한 정량적 연구

홍성모,박은광,김경열,박진주,이민구,이창규,이진규,권영순,Hong, Sung-Mo,Park, Eun-Kwang,Kim, Kyeong-Yeol,Park, Jin-Ju,Lee, Min-Ku,Rhee, Chang-Kyu,Lee, Jin-Kyu,Kwon, Young-Soon 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.1

This study investigated refinement behaviors of TiC powders produced under different impact energy conditions using a mechanical milling process. The initial coarse TiC powders with an average diameter of 9.3 ${\mu}m$ were milled for 5, 20, 60 and 120 mins through the conventional low energy mechanical milling (LEMM, 22G) and specially designed high energy mechanical milling (HEMM, 65G). TiC powders with angular shape became spherical one and their sizes decreased as the milling time increased, irrespective of milling energy. Based upon the FE-SEM and BET results of milled powders, it was found initial coarse TiC powders readily became much finer near 100 nm within 60 min under HEMM, while their sizes were over 200 nm under LEMM, despite the long milling time of up to 120 min. Particularly, ultra-fine TiC powders with an average diameter of 77 nm were fabricated within 60 min in the presence of toluene under HEMM.

태권도 돌려차기 시 기술 수준에 따른 몸통, 골반, 지지 다리의 운동학적 변인 비교

김재웅 ( Kim Jae-woong ),한기훈 ( Han Ki-hoon ),김제민 ( Kim Je-min ),이상우 ( Lee Sang-woo ),권문석 ( Kwon Moon-seok ),터틀노엘 ( Noelle J. Tuttle ) 국기원 2018 국기원태권도연구 Vol.9 No.1

이 연구의 목적은 태권도 돌려차기 시 기술 수준에 따른 몸통, 골반, 지지 다리의 운동학적 변인을 비교 분석하는 데 있다. 본 연구를 위해 블랙 벨트 소지자로서 기술 수준에 따라 중급자10명, 상급자 9명이 실험에 참여하였다. 3차원 동작 분석 시스템을 사용하여 골반, 몸통, 지지다리의 방향각을 산출하였다. Start, Toeoff, MKF, Max, Impact, Min에서 그룹 간의 평균 방향각을 비교하기 위하여 독립표본 t-검정을 하였다. MKF, Impact, Min에서 골반의 좌측 기울어짐 각도가 그룹 간의 유의한 차이가 나타났다. Start와 Max에서 지지 다리의 엉덩관절 굴곡 각도와 MKF에서 지지 다리의 엉덩관절 외전 각도 사이에 유의한 차이가 있었다. 이상의 결과를 볼 때, 상급자들은 푸쉬단계에서 엉덩관절의 굴곡 각도가 증가 되었고, MKF에서는 외전 각도가 감소하였다. 또한, 스트라이크 단계에서 골반의 좌측 기울어짐 각도는 감소하였다. The study purpose was to investigate skill level differences on trunk, pelvis, and supporting leg kinematics in a Taekwondo roundhouse kick. 10 intermediate and nine expert male black-belt holders executed roundhouse kicks at a target. Orientation angles of the pelvis, trunk, and supporting -thigh, -shank, and -foot were obtained through a three-dimensional video motion analysis. Orientation angles at Start, Toeoff, Maximum Knee Flexion(MKF), Impact, Maximum angle(Max), and Minimum angle(Min) were compared between groups using independent t-tests(p<.05). Significant differences between groups were found in the pelvis left lateral tilted position at MKF, Impact, and Min; significant differences were also found in the supporting hip joint flexed position at Start and Max, and abducted position at MKF. It was concluded that higher performers increased the hip joint flexion angle in the Push phase, decreased abduction angle at MKF, and decreased the pelvis left tilted angle in the Strike phase.

저농도 이산화탄소 포집용 흡착제 개발 및 최적조건에 관한 연구

이주열 ( Ju Yeol Lee ),박덕신 ( Duck Shin Park ),조영민 ( Young Min Cho ),권순박 ( Soon Park Kwon ),황윤호 ( Yoon Ho Hwang ),송형진 ( Hyung Jin Song ),이상봉 ( Sang Bong Lee ) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.1

본 논문은 다양한 시설내에 적은 농도의 CO2 제거를 위한 선택적 CO2 흡수능력을 향상시킨 흡착제의 효율평가에 관한 것이다. 직경 4mm의 구형 흡착제는 시판용 제올라이트에 첨가제, 물, 바인더, LiOH를 섞어 제조하였다. 칼럼테스트에서 400분 이내에 90% 이상의 CO2흡착효율을 나타내었고, 흡착필터모듈 흡착능력을 평가하기 위해 회분식과 연속식타입의 챔버테스트가 시행되었다. 회분식테스트에서 30분 이내에 약 92%의 CO2가 제거되는 것을 확인하였다. 연속식테스트에서 30분 이내 70%의 CO2가 제거효율을 보였으며, 2,500ppm 이상의 CO2가 제거되는 것을 확인하였다. 재현성테스트를 수차례 수행한 결과 15일동안 1,000ppm 이상의 CO2가 연속적으로 제거됨을 보였다. TGA 분석법을 이용한 흡착량 분석에서 흡착제 g당 5.0mmol의 CO2를 흡착하는 것으로 나타났다. 본 연구에서 개발된 흡착제는 상온에서 저농도 CO2 실내환경에 적용가능한 것으로 판단된다. In this study, CO2 adsorbent was developed for removing low concentration of CO2 in multiple-use facilities. The efficiency of the adsorbent which was improved selective CO2 adsorption capabilities was evaluated. The pellet type adsorbent was modified from a commercial zeolite with mixing LiOH, binder, additives, and H2O. Column tests showed over 90 % of CO2 was adsorbed within 400min. Chamber tests including batch and continuous types were performed for evaluating the adsorbent module. By batch tests, it was evaluated that about 92 % of CO2 was removed within 30 min. By continuous tests, 70% of CO2 was removed within 30 min. It was analyzed that over 2,500 ppm of CO2 was continuously removed as shown chamber tests. The reproducibility tests repeatedly performed for 15 days shows that over 1,000 ppm of CO2 was continuously removed. Adsorption capacity of the developed adsorbent was 5.0mmol CO2/g adsorbent which was analyzed by TGA. It was estimated that the modified adsorbent was applicable to low CO2 concentration and low temperature of indoor environment.