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.

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.

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.

Optical properties of hydrogel contact lens material containing 1-vinylimidazole

Min-Jae Lee,Dong-Hyun Kim,A-Young Sung 대한시과학회 2014 대한시과학회지 학술대회 Vol.2014 No.05

Purpose: This study evaluated the physical and optical characteristics of hydrophilic contact lens polymerized with addition of 1-vinylimidazole in the basic hydrogel contact lens material, and in particular, the utility of 1-vinylimidazole as a contact lens material for ophthalmologic devices was investigated. Methods: This study used 1-vinylimidazole with the cross-linker EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. The polymerization of the contact lens material was conducted through thermal polymerization in 100°C for about 40 mins. To produce the high functional contact lenses, a cast mould method was used. Results: The physical properties of the hydrogel ophthalmic material were investigated by measuring the average value of refractive index, water content and optical transmittance. The refractive index of 1.4330~1.4408, water content of 36.10~38.59%, UV-A transmittance of 90.0~72.2% and UV-B transmittance of 88.6%~64.2% and visible ray transmittance of 89.2~91.8% were obtained. The transmittance for visible light was over 89% in all combinations with 1-vinylimidazole and the transmittance for UV reduced up to a certain level in certain combinations with 1-vinylimidazole. Conclusions: Based on the results of this study, the produced copolymer can be estimated to be suitable for use as ophthalmic lens material for UV- blocking effects.

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

Young Min Choi,Sang Hoon Lee,Jee Hwan Choe,Kyoung Heon Kim,Min Suk Rhee,Byoung Chul Kim 한국축산식품학회 2013 한국축산식품학회지 Vol.33 No.5

The objective of this study was to investigate the effects of supercritical carbon dioxide (SC-CO2) 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 CO2 at 31.1oC for 10 min. The SC-CO2 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-CO2 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-CO2 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-CO2 applied at 15.2 MPa and 31.1oC for 10 min, treatment samples showed a tenderer meat than the control samples. Therefore, the SC-CO2 treatment conditions had no adverse effects on the sensory quality characteristics of the marinated meat products.

Effect of Jaeumkanghwatang (JEKHT), a Polyherbal Formula on the Pharmacokinetics Profiles of Tamoxifen in Male SD Rats (1)

Min A Kwak,Soo Jin Park,Sung Hwan Park,Young Joon Lee,Sae Kwang Ku 대한한의학회 2016 대한한의학회지 Vol.37 No.2

유아의 성별, 연령에 따른 체력 특성

전영남,양점홍,김수진,이성민 釜山大學校 附設 體育科學硏究所 2005 體育科學硏究所 論文集 Vol.21 No.2

The purpose of this study is to examine the characteristics of young children's fitness development in accordance with gheir gender and age, providing information necessary for an effective physical education instruction for young children's growth and development. For the purpose, this researcher selected total 257 young children from K Kindergarten located at K-gu in B Metropolitan City who consisted of 73 boys and 45 girls, both of were fully aged 4, and 83 boys and 56 girls, fully aged 5.......

진공열간가압성형 (VHP) 법 및 압출로 제조한 SiCp/Al 및 SiCp/2024Al 복합재료의 동적탄성계수와 감쇄능 (내부마찰) : 금속기 복합재료의 동적탄성계수 및 감쇄능 측정

김영만,조기현,이경민,홍성길 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.9

To shorten the processes of MMC fabrication, a number of techniques are being studied. In this study, a new process for MMC's fabrication was developed utilizing vacuum hot pressing and subsequent extrusion. MMC's with pure Al and 2024Al matrices reinforced with various volume fractions of SiC particulates were produced at 400℃ by vacuum hot pressing(VHP), followed by direct extrusion with extrusion ratios of 10:1 at 480℃ at constant ram speed of 2㎜/sec. The effects of extrusion pressure and relative density according to the volume fractions of the reinforcement were compared with the resultant metallurgical microstructures. Young's moduli of the manufactured composites were measured by the sonic resonance method, damping capacity by free decay method. Measured Young's moduli of the composites at room temperature were compared with the predictions based on Rule of Mixtures, Halpin-Tsai and Mean-field models. Measured Young's moduli of the composites are in good agreement with the predictions based on Mean-field model. The composites reinforced with finer particles showed higher damping capacity under the same amount of SiC reinforcement.

폐 젤리충진 통신케이블로부터 고순도 구리회수를 위한 대형화 방안 연구

조성수 ( Sung Su Cho ),이수영 ( Soo Young Lee ),서민혜 ( Min Hye Seo ),엄성현 ( Sung Hyun Uhm ) 한국공업화학회 2014 공업화학 Vol.25 No.2

폐 젤리충진 통신케이블로부터 고순도 구리회수를 위하여 실리콘계 및 톨루엔계 합성 열매유와 폐식용유를 사용하여 적용성을 평가하였다. 실리콘계 오일의 경우 모든 조건에서 분리효율이 낮은 반면, 톨루엔계 오일 및 폐식용유의 경우 처리온도 및 시간을 조절함에 따라 높은 분리효율을 얻을 수 있었다. 폐식용유를 사용하는 50 kg급 밀폐형 대용량 설비를 이용하여 300 ℃에서 60 min 이상 처리할 경우 99.2% 이상의 고순도 구리와이어를 100% 회수할 수 있었다. We examined and compared the feasibility of vegetable oils with synthetic thermal conductive oils to recover highly purified copper metal from waste jelly-filled communication cables. While polydimethylsiloxane shows relatively poor separation effi-ciency under entire operating conditions, dibenzyltoluene and waste vegetable oil show the high separation efficiency if the appropriate operating temperature and time were given. By running 50 kg-class equipment with waste vegetable oils, we ob-tained 100% copper metal recovery with 99.2% purity at 300 ℃ for 60 min.