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.

사과 과실 비대기 고유진동과 과실 낙과간 관계 추정

최영민(Young Min Choi),유기표(Ki-Pyo You),최동근(Dong Geun Choi) 한국원예학회HST 2025 원예과학기술지 Vol.43 No.1

본 연구는 태풍이 주로 도래하는 시기에 사과 ‘후지’(Malus domestica Borkh) 과실의 부착력 변화를 조사하고, 풍동 및 진동대를 이용한 시뮬레이션을 통해 낙과와 관련된 정보를 획득하고자 수행하였다. 과실 부착력은 과실을 잡아당겼을 때 낙과하는 시점의 인장력을 조사하였다. 생육기(7–9월) 과실 부착력은 성숙기에 가까워질수록 감소하는 경향이었으나 통계적인 유의성은 없었다. 반면 과경축을 기준으로 당기는 각도를 0, 30, 60도로 측정했을 때의 부착력은 각도가 커질수록 유의하게 감소하였다. 가속도센서를 활용한 주지의 기부, 중간과 바깥쪽의 고유진동수는 각각 52.0cycles·min^-1, 332.2cycles·min^-1, 346.5cycles·min^-1로 측정되었으며, 주지의 운동 방향은 수직(443cycles·min^-1)보다 수평(874.2cycles·min^-1)적인 변위에서 더 높았다. 과실의 고유진동수는 496.9cycles·min^-1로 측정되었다. 추가적으로 주지의 60cm 부위(원줄기로부터)를 결속하여 고유진동을 측정한 결과, 무결속보다 고유진동수가 낮았으며, 상대적으로 수직변위가 수평변위보다 낮았다. 풍동을 활용한 실험에서 0–9m·s^-1의 풍속에서 과실은 낙과하지 않았으며, 풍속별 평균 변위는 풍속이 강해질수록 증가(최대 17mm)하는 경향을 보였다. 진동대를 이용한 실험은 풍동 실험에서 산출된 변위계수를 근거로 5–30mm까지 변위값을 적용하였으며, 진동방식은 ‘흔들림(pendulum)’ 형태로 과실이 착과된 결과지에 진동을 주었다. 과실 낙과는 변위계수 10mm(고유진동수 57.0-72.6cycles·min^-1)부터 낙과가 시작되었고, 변위계수가 증가할수록 낙과까지의 소요시간은 단축되었다. 변위계수와 풍속과의 관계식에서 10mm의 변위계수는 풍속 6–9m·s^-1를 의미하지만, 이와 같은 결과는 재배 특성(수형, 잎, 과중, 착과량, 과실 이층부의 성숙도 등)과 자연적 바람의 특성(돌풍, 와류, 풍향 등)이 적용되지 않아 보다 낮은 풍속에서도 낙과가 발생할 수 있다. 따라서 바람은 과실을 포함한 수체에 1차 변위를 발생시킨 후 과중과 가지의 탄력성에 의해 2차 변위를 유도할 수 있으며, 이러한 1, 2차 변위에 의해 낙과하는 것으로 추정된다. This study was conducted to investigate changes in the adhesivity of ‘Fuji’ apple (Malus domestica Borkh) fruits during the period when typhoons mainly occur and to obtain agricultural engineering information related to fruit drop through a simulation using a wind tunnel and shaking table. Fruit adhesivity was assessed by measuring the tensile force at the time of fruit drop when pulling the fruit from the tree. Fruit adhesivity during the growing season (July to September) tended to decrease as maturity approached, but this was not statistically significant. On the other hand, fruit adhesivity when measured at artificial drop angles of 0°, 30°, and 60° based on the fruit stalk decreased significantly as the angle increased. Using an acceleration sensor, the natural frequencies of the inner, middle, and outer parts of the scaffold branch (in the direction of the main stem) were found to be 52.0 cycles·min^-1, 332.2 cycles·min^-1, and 346.5 cycles·min^-1, respectively. The natural frequency according to the movement direction of the scaffold branch was higher for horizontal displacement (874.2 cycles·min^-1) than for vertical displacement (443 cycles·min^-1). The natural frequency of the fruit was measured and found to be 420.5 cycles·min^-1. Additionally, as a result of measuring the natural frequency after binding 60 cm parts (from the main stem) of the scaffold branches, the natural frequency was found to be lower than the control (no binding), and the vertical displacement was lower than the horizontal displacement. Using a wind tunnel, fruits did not fall at wind velocity of 0 to 9 m·s^-1, and the average displacement (up to 17 mm) tended to increase as the wind velocity was increased. In an experiment using a shaking table, displacement values in the range of 5 to 30 mm were applied based on the displacement coefficient calculated in the wind tunnel experiment, and the bearing branch of the apple tree was shaken using a ‘pendulum’ type of vibration method. The fruit drop began with a displacement coefficient of 10 mm, and the time required for fruit drop shortened as the displacement coefficient was increased. In the relationship between the displacement coefficient and the wind velocity, a displacement coefficient of 10 mm indicated a wind velocity of 6 to 9 m·s^-1, but this result may lead to fruit drop even at lower wind velocities because certain cultivation characteristics (e.g., tree form, number of leaves, fruit yield, abscission layer maturity of fruit) and natural wind characteristics (e.g., gusts, eddies, wind direction) were not taken into account. Wind can cause primary displacement in apple trees containing fruits and can then induce secondary displacement due to the weight of the fruit and the elasticity of the branches, and it is presumed that these primary and secondary displacements cause fruit drop.

무용전공학생의 호흡순환기능 및 혈중젖산농도에 관한 비교연구

이종희,김말애,손흥기,김민정 경희대학교 체육과학연구소 1996 體育學論文集 Vol.24 No.-

The purpose of this study is to investigate the cardiovascular function and blood lactate in female by part of dance major in university. For this purpose a total of 32 female students, attending university K in Seoul participated in the study. The subjects were selected randomly 24 female students majored in dance in university(Korean dance: 8, Modern dance: 8, Ballet: 8), and 8 regular female students, who did not have any dance experience. The results of the study were as follows; 1.Cardiovascular function 1)In factors of rest HR showed in Control group 76.50±3.74 beats/min, Korean dance group 72.13±4.85 beats/min, Modern dance group 71.50±4.93 beats/min, Ballet dance group 68.8±4.19beats/min. Among these group there was significantly(p〈.05). 2)In factors of HRmax showed in Korean dance group 200.63土4.78 beats/min, , Ballet dance group 198.00±6.28beats/min, Modern dance group 197.63±6.65beats/min Control group 189.75±10.51beats/min. Among these group there was significantly(p〈.05). 3)In factors of VO2/kg showed in Ballet dance group 44.46±4.09㎖/min, Korean dance group 43.95±2.95㎖/min, Modern dance group 40.73±3.26㎖/min, Control group 34.33±2.28㎖/min. Among these group there was significantly(p〈.001). 4)In factors of VCO2 showed in Korean dance group 84.31ℓ/min, Modern dance group 2.60±0.44ℓ/min, Ballet dance group 2.52±0.23ℓ/min, Control group 2.23±0.34ℓ/min. Among these group there was not significantly. 5)In factors of art-out time showed in Korean dance group 931±52.92sec, Modern dance group 916.75±40.96sec, Ballet dance group 908.88±28.44sec, Control group 809.38±70.02sec. Among these group there was significantly(p〈.001). 2.Blood lactate 1)In factors of rest time blood lactate showed in Ballet dance group 1.17±0.26.mM/ℓ, Control group 1.11±0.21mM/ℓ , Korean dance group 1.09±0.28mM/ℓ , Modern dance group 1.06±0.33mM/ℓ Among these group there was not significantly. 2)In factors of all-out time blood lactate showed in Control group 9.14±0.92mM/ℓ, Ballet dance Broup 7.79±1.14mM/ℓ, Korean dance group 7.67±1.51mM/ℓ, Modern dance group 7.42±1.18mM/ℓ, Among these group there was not significantly. 3)In factors of recovery 3 minute blood lactate showed in Control group 9.52±0.94mM/ℓ, Ballet dance group 7.68±1.73mM/ℓ, Modern dance group 7,61±0.89mM/ℓ, Korean dance group 7.52±1.78mM/ℓ. Among these group there was significantly(p〈.05). 4) In factors of recovery 5 minute blood lactate showed in Control group 9.91±1.22mM/ℓ, Korean dance group 7.97±2.38mM/ℓ, Ballet dance group 7.86±1.86mM/ℓ, Modern dance group 7.51±1.10mM/ℓ, Among these group there was significantly(p〈.05). 5)In factors of recovery 10 minute Control group 8.99±0.97mM/ℓ, Ballet dance group 6.98±1.65mM/ℓ, Korean dance group 6.96±2.08mM/ℓ, Modern dance group 6.78±1.38mM/ℓ, Among these group there was significantly(p〈.05).

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.

가압가열 및 Microwave 처리가 생면의 품질에 미치는 영향

박시우,김꽃봉우리,김민지,강보경,박원민,김보람,박홍민,최정수,최호덕,안동현,Bark, Si-Woo,Kim, Koth-Bong-Woo-Ri,Kim, Min-Ji,Kang, Bo-Kyeong,Pak, Won-Min,Kim, Bo-Ram,Park, Hong-Min,Choi, Jung-Su,Choi, Ho-Duk,Ahn, Dong-Hyun 한국식품영양학회 2013 韓國食品營養學會誌 Vol.26 No.4

중력분을 이용하여 제면한 후 가압가열, microwave 및 가압가열과 microwave 병행 처리한 후, 생면 및 삶은 면의 품질에 미치는 영향에 대하여 알아보았다. 생면의 pH는 microwave 1 min 처리구에서 무처리구와 유의적인 차이를 보이지 않았으며, 수분 함량은 autoclave 50 min 처리구에서 무처리구와 유의적인 차이를 보이지 않았고, 그 외의 처리구에서는 모두 수분 함량이 감소함을 확인하였다. 면의 색도 측정 결과는 명도는 무처리구에 비해 모든 처리구에서 감소하였으며, 적색도는 microwave 1 min 처리구는 감소한 반면, 나머지 처리구는 증가하였다. 황색도는 autoclave 50 min 처리구와 autoclave 50 min/microwave 1 min 병행 처리구에서 증가한 반면, 나머지 물리적 처리구에서는 감소하였다. 삶은 면의 색도에서는 명도, 적색도, 황색도 모두에서 무처리구에 비하여 물리적 처리구에서 증가한 값을 나타내었다. 물성 측정 결과는 경도, 부착성, 응집성, 검성, 복원성에서 무처리구와 비교시 microwave 1 min 처리구는 유의적으로 감소하였으며, 그 외 처리구에서는 유의적으로 증가한 값을 나타내었다. 탄력성과 전단력은 모든 처리구에서 유의적으로 증가하였으며, 인장력은 가압가열 30 min 처리구와 무처리구가 유의적인 차이를 보이지 않았으나, 나머지 물리적 처리구에서는 유의적으로 증가하였다. 관능 평가 결과는 생면의 경우 색 항목에서 물리적 처리구들이 유의적으로 낮은 점수를 받았다. 맛, 질감, 향 항목에서는 무처리구와 물리적 처리구간 유의적 차이를 보이지 않았다. 전체적인 기호도에서는 microwave 1 min 처리구가 가장 높은 점수를 얻었으며, 가압가열(50 min)과 microwave(1 min) 병행 처리구는 무처리구와 비슷한 점수를 얻었다. 따라서 제면 후 가압가열 및 microwave 처리가 생면 및 삶은 면에 있어서 색과 질감 항목을 보완, 개선시킨다면 알러겐성이 저감화된 면을 제품화하는데 적합할 것으로 사료되어진다.

태연혈(太淵穴)의 유침 시간에 따른 체온 변화 -적외선체열촬영(赤外線體熱撮影)을 중심으로-

이봉효 ( Bong Hyo Lee ),이경민 ( Kyung Min Lee ),박지하 ( Ji Ha Park ),김민서 ( Min Seo Kim ),김산들 ( San Deul Kim ),박병규 ( Byeong Gyu Park ),양현동 ( Hyun Dong Yang ),예성호 ( Sung Ho Yea ),이호정 ( Ho Jung Lee ),최재원 ( Jae 경락경혈학회 2012 Korean Journal of Acupuncture Vol.29 No.2

Objectives: This study was performed to find the desirable remaining time of needle in the acupuncture treatment. Methods: The 21 volunteers were given acupuncture at LU9 vertically and needles were remained for 2 min, 10 min, 15 min, 30 min, respectively. The thermographic change induced by acupuncture was measured with Digital Infrared Thermographic Image at the following acupoints: LU11, LU10, LU9, LU8, LU5, LU1, and PC7. The statistical significance of thermographi change was evaluated using paired t-test and post hoc Wilcoxon test. Results: The most significant changes after acupuncture were produced when needles were remained for 10 min or 15 min. LU11, LU5, LU1, and PC7 were the point at which all of the remaining time produced significant change commonly. At LU11, the biggest change was produced when needle was remained for 15 min, while at LU5, LU1, and PC7, the biggest change was produced when needle was remained for 30 min, and the smallest change was produced when needle was remained for 10 min at all of acupoints of LU11, LU5, LU1, and PC7. The unbalance between left side and right was decreased the most largely in 15 min group. Conclusions: The results of this study suggest that the desirable remaining time of acupuncture needle might be 15 min.

전송율 향상을 위한 다단계 상호연결망

신용태,이철희,조민수 崇實大學校 生産技術硏究所 1996 論文集 Vol.26 No.1

This paper proposed two Multi-statge Interconnection Network(MIN) that had multiple outlet to improve throughput. These proposed MINS were made of Clos MIN, well known Non-blocking MIN. These proposed MINs were called ECFS(Expanded Clos Switch Fabric) adn TCSF(Tandem Clos Switch Fabric). ECFS was consist of expanded number of switchs for multiple oulet. TCSF was consist of serial Clos MIN for multiple outlet. Performance evaluation of these proposed MINs was calculated arrival probability of packet through the MIN. In teh result, these proposed MINs with multiple outlet had higher throughput than existed MIN with single outlet. We know the fact that as the outlet of MIN increase, throughput of MIN increase.

Accuracy of cardiac output measurements during off-pump coronary artery bypass grafting: according to the vessel anastomosis sites

Sung Yong Park,Dae Hee Kim,Han Bum Joe,Ji Young Yoo,Jin Soo Kim,Min Kang,Yong Woo Hong 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.62 No.5

Background: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB. Background: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB.

Reduction of Bacillus cereus Contamination in Biofilms on Stainless Steel Surfaces by Application of Sanitizers and Commercial Detergent

Lee, Min-Jeong,Ha, Ji-Hyoung,Kim, Yong-Su,Ryu, Jee-Hoon,Ha, Sang-Do The Korean Society for Applied Biological Chemistr 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.1

We established the effectiveness of a washing, detergent and sanitizer treatments for reducing Bacillus cereus (B. cereus) contamination in biofilms on stainless steel surfaces. A water treatment did not affect biofilms and chlorine treatments at 200 ppm for 10 min and 300 ppm for 5 min, iodophor at 200 ppm for 10 min, and QAC at 400 ppm for 10 min were used to eliminate all B. cereus cells. B. cereus cells after detergent treatment were eliminated by chlorine at 100 ppm for 10 min, 200 ppm for 5 min, and 300 ppm for 3 min, and with iodophor at 100 ppm for 10 min and 200 ppm for 10 min, and QAC at 400 ppm for 10 min.

과열증기처리 반탄화 추출물의 항산화 효과 검증에 관한 연구

오근혜(Geun Hye Oh),남정빈(Jeong Bin Nam),양승민(Seung Min Yang),정원희(Won Hee Joung),정진산(Jin San Jeong),신종민(Jong Min Shin),강석구(Seog Goo Kang) 한국펄프·종이공학회 2018 펄프.종이기술 Vol.50 No.2

The antioxidant properties of the extracts from torrefied wood subjected to superheated steam treatment were investigated. Total polyphenolics, total flavonoids, DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity, reducing power, and FRAP (Ferric reducing antioxidant power) were determined to evaluate antioxidant activity. The total polyphenol content was 879.67±40.41 ㎎/mL at a concentration of 25 g/mL when the extract was subjected to a temperature of 300℃ for 10 min, and 759.67±25.17 ㎎/mL at a concentration of 25 g/mL at 350℃ for 10 min. The value of at 300℃ was 15.79% higher than that obtained at 350℃. Total flavonoid content was 111.18±3.55 ㎎/mL at a concentration of 25 g/mL at 300℃ for 10 min, and 80.58±2.58 ㎎/mL at a concentration of 25 g/mL at 350℃ for 10 min. The value at 300℃ was 37.97% higher than that obtained at 350℃. For the DPPH free radical scavenging activity, the highest scavenging activity was observed at a concentration of 6 g/mL. DPPH free radical scavenging activity at a concentration of 6 g/mL at 300℃ for 10 min was 89.83±0.03%, whereas at 350℃ for 10 min at the same concentration, it was found to be 87.99±0.1%. The value at 300℃ was 2.09% higher than that obtained at 350℃. Reducing power was determined to be 3.59±0.04 at a concentration of 25 g/mL at 300℃ for 10 min, and 2.92±0.1 at a concentration of 25 g/mL at 350℃ for 10 min. The value at 300℃ was 22.94% higher than that obtained at 350℃. FRAP was 1742±37 μM at a concentration of 25 g/mL at 300℃ for 10 min, and 1106±8 μM at a at 350℃ for 10 min. At 300℃, the FRAP value was 57.50% higher than that obtained at 350℃. Based on these results, we suggest that torrefied wood treated with superheated steam can be used in various applications because of its effective antioxidant properties.