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Hydrodynamics of air-kerosene bubble column under elevated pressure in homogeneous flow regime

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Chinese Journal of Chemical Engineering 2021年第5期34卷 190-202页

作者： Bay Van Tran son Ich Ngo young-Il Lim Keon Bae Dong Hyun Lee Kang-Seok Go Nam-Sun Nho Center of Sustainable Process Engineering(CoSPE) Department of Chemical EngineeringHankyong National UniversityGyeonggi-doAnseong-siJungang-ro 32717579Republicof Korea School of Chemical Engineering Sungkyunkwan University2066 Seobu-roJanganSuwon 16419Republic of Korea Center for Convergent Chemical Process(CCP) 141 Gajeong-roYuseong-guDaejeon 34114Republic of Korea

A multiphase computational fluid dynamics(CFD)model coupled with the population balance equation(PBE)was developed in a homogeneous air-kerosene bubble column under elevated pressure(P).The specific pressure drop(ΔP/L),gas holdup(α_(G)),and Sauter mean diameter(d_(32))were experimentally measured in the bubble column with 1.8 m height and 0.1 m inner diameter,which was operated at a superficial gas velocity of 12.3 mm·s^(-1),and P=1-35 bar(1 bar=10^(5) Pa).A modified drag coefficient model was proposed to consider the effect of bubble swarm and pressure on hydrodynamics of the bubble *** Luo breakage model was modified to account for liquid density,viscosity,surface tension and gas ***ΔP/L,α_(G),and d_(32) obtained from the CFD model were compared with experimental data,and the gas density-dependent parameters of the CFD model were *** increasing P from 1 to 35 bar,theα_(G) varied from 5.4%to 7.2% and the d32 decreased from 2.3 to 1.5 *** CFD-PBE model is applicable to predict hydrodynamics of pressurized bubble columns for gas-organic liquid in the homogeneous regime.

关键词： Bubble column Air-kerosene High pressure Homogenous regime Computational fluid dynamics (CFD) Population balance equation (PBE)

Incidence and Related Risk Factors of Junctional Ectopic Tachycardia in Infants after Cardiac Surgery for Congenital Heart Disease

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Congenital Heart Disease 2022年第5期17卷 569-578页

作者： Jae Hee Seol Se Yong Jung Jae young Choi Han ki Park young Hwan Park Nam Kyun kim Department of Pediatrics Congenital Heart Disease CenterDivision of Pediatric CardiologySeverance Cardiovascular HospitalYonsei University College of MedicineSeoulKorea Department of Pediatrics Yonsei University Wonju College of MedicineWonjuKorea Department of Thoracic and Cardiovascular Surgery Division of Cardiovascular SurgeryCongenital Heart Disease CenterSeverance Cardiovascular HospitalYonsei University College of MedicineSeoulKorea Department of Pediatrics and Biomedical Engineering School of MedicineEmory UniversityAtlantaUSA

Objective:Junctional ectopic tachycardia is common after cardiac surgery for congenital heart ***,its incidence and related risk factors in infants after cardiac surgery are not well *** objective of this study was to determine the overall incidence and related risk factors for junctional ectopic tachycardia in neonates and ***:We enrolled a total of 271 patients aged<1 year who underwent open cardiac surgery at Severance Cardiovascular Hospital from January 2018 to December *** criteria were immediate postoperative mortality,other arrhythmias detected in the perioperative period,and ***:The overall incidence of junctional ectopic tachycardia was 12.9%.The logistic regression analysis revealed that longer cardiopulmonary bypass time,surgery involving atrioventricular node stretching,and the presence of early repolarization on preoperative electrocardiography increased the risk of junctional ectopic *** with junctional ectopic tachycardia had longer intubation time and intensive care unit ***:Junctional ectopic tachycardia is a common arrhythmia after cardiac surgery for congenital heart disease in ***,infants developing junctional ectopic tachycardia after cardiac surgery have specific preoperative electrocardiography *** risk factors for junctional ectopic tachycardia were associated not only with surgical procedural factors but also with preoperative electrocardiographic parameters.

关键词： Junctional ectopic tachycardia congenital heart disease early re-polarization

Characterization of plasma electrolytic oxide formed on AZ91 Mg alloy in KMnO_4 electrolyte

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中国有色金属学会会刊：英文版 2009年第4期19卷 829-834页

作者： Duck-young HWANG ki-Ryong SHIN Bongyoung YOO Dong-Heon LEE Deok-Yong PARK Dong-Hyuk SHIN Department of Metallurgy and Materials Science Hanyang University Ansan 426-791 Korea Department of Applied Materials Engineering Hanbat National University Daejon 305-719 Korea 不详

The aim of this work is to investigate microstructure,corrosion resistance characteristics and nanohardness of the oxide layer on AZ91 Mg alloy by applying different voltage with KMnO4 contained *** are lots of closed pores that are filled with another oxide compound compared with the typical surface morphology with pore coated until 350 V of coating *** thickness of oxide layer increases with increasing coating *** oxide layer formed on AZ91 Mg alloy in electrolyte with potassium permanganate consists of MgO and *** potential of the oxide layer on AZ91 Mg alloy obtained at different plasma electrolytic oxidation(PEO) reaction stages increases with increasing coating *** corrosion resistance of AZ91 Mg alloy depends on the existence of the manganese oxide in the oxide *** inner barrier layer composed of the MgO and Mn2O3 may serve as diffusion barrier to enhance the corrosion resistance and may partially explain the excellent anti-corrosion performance in corrosion *** values increase with increasing coating *** increase in the nanohardness may be due to the effect of manganese oxide in the oxide layer on AZ91 Mg alloy coated from electrolyte containing KMnO4.

关键词： AZ91镁合金等离子体电解高锰酸钾氧化特性电解液氧化层厚度纳米硬度耐腐蚀性

Advanced heterolytic H_(2) adsorption of K-added Ru/MgO catalysts for accelerating hydrogen storage into aromatic benzyltoluenes

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Journal of Energy Chemistry 2022年第8期31卷 333-343,I0009页

作者： Tae Wan kim Hwiram Jeong Yeongin Jo Dongun kim Ji Hoon Park Seok ki kim young-Woong Suh Department of Chemical Engineering Hanyang UniversitySeoul 04763Republic of Korea Environmental&Sustainable Resources Research Center Korea Research Institute of Chemical TechnologyDaejeon 34114Republic of Korea Department of Chemical Engineering Ajou UniversitySuwon 16499Republic of Korea

Herein,we report a highly active K-added Ru/MgO catalyst for hydrogen storage into aromatic benzyltoluenes at low temperatures to advance liquid organic hydrogen carrier *** hydrogenation activity of Ru/K/MgO catalysts exhibits a volcano-shaped dependence on the K content at the maximum with 0.02 wt%.This is in good agreement with the strength and capacity of H_(2) adsorption derived from basicity,despite a gradual decrease in the textural property and the corresponding increase in the Ru particle size with increasing the K *** functional theory calculations show that heterolytic hydrogen adsorption properties(strength and polarization)are facilitated up to a specific density of K on the Ru–MgO interface and excessive K suppresses heterolytic H_(2) adsorption by direct interaction between K and hydrogen,assuring the hydrogenation activity and H_(2) adsorption capability of Ru/K/MgO ***,the Ru/K/MgO catalyst,when K is added in an optimal amount,is highly effective to accelerate hydrogen storage kinetics at low temperatures owing to the enhanced heterolytic H_(2) adsorption.

关键词： Chemical hydrogen storage Supported Ru catalysts Ru–MgO interface Heterolytic H_(2)adsorption Charge transfer Potassium promotion

Analysis of expanded criteria to select candidates for active surveillance of low-risk prostate cancer

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Asian Journal of Andrology 2015年第2期17卷 248-252,I0008,I0009页

作者： Jung ki Jo Hart Sol Lee young Ik Lee Sang Eun Lee Sung Kyu Hong Department of Urology Seoul National University Bundang Hospital Seongnam Korea.

We aimed to analyze the value of each criterion for clinically insignificant prostate cancer （PCa） in the selection of men for active surveillance （AS） of low-risk PCa. We identified 532 men who were treated with radical prostatectomy from 2006 to 2013 who met 4 or all 5 of the criteria for clinically insignificant PCa （clinical stage 〈 T1, prostate specific antigen [PSA] density 0.15, biopsy Gleason score 〈 6, number of positive biopsy cores 〈 2, and no core with 〉 50% involvement） and analyzed their pathologic and biochemical outcomes. Patients who met all 5 criteria for clinically insignificant PCa were designated as group A （n -- 172）, and those who met 4 of 5 criteria were designated as group B （n = 360）. The association of each criterion with adverse pathologic features was assessed via logistic regression analyses. Comparison of group A and B and also logistic regression analyses showed that PSA density 0.15 ng ml-1 and high （〉7） biopsy Gleason score were associated with adverse pathologic features. Higher （〉 Tlc） clinical stage was not associated with any adverse pathologic features. Although 〈 3 positive cores were not associated with any adverse pathology, 〉4 positive cores were associated with higher risk of extracapsular extension. Among potential candidates for AS, PSA density ~ 0.15 ng ml-~ and biopsy Gleason score ~ 6 pose significantly higher risks of harboring more aggressive disease. The eligibility criteria for AS may be expanded to include men with clinical stage T2 tumor and 3 positive cores.

关键词： prediction prostate prostatectomy prostatic neoplasms risk

Validation of Sea Level Data in the East Asian Marginal Seas: Comparison between TOPEX/POSEIDON Altimeter and In-Situ Tide Gauges

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Advances in Atmospheric Sciences 2003年第4期20卷 650-660页

作者： Yong-Hoon YOUN Im Sang OH ki-Hyun kiM young-Hyang PARK Jong Woo kiM Meteorological Research Institute/Korea Meteorological Administration SeoulKoreaResearch Institute of OceanographySeoul National UniversitySeoulKoreaDepartment of Earth SciencesSejing UniversitySeoulKoreaLaboratoire d'Oceanographie PhysiqueMuseum National d'Histoire NaturelleParisDepartment of Earth SciencesSejong UniversitySeoulKorea

In an effort to assess the reliability of satellite altimeter systems, the authors conduct a comparative analysis of sea level data that were collected from the TOPEX/POSEIDON (T/P) altimeter and 10 tide gauges (TG) near the satellite passing ground tracks. The analysis is made using datasets collected from marginal sea regions surrounding the Korean Peninsula at T/P cycles of 2 to 230, which correspond to October 1992 to December 1998. Proper treatment of tidal errors is a very critical step in data processing because the study area has very strong tide. When the T/P data are processed, the procedures of Park and Gamberoni (1995) are adapted to reduce errors associated with the tide. When the T/P data are processed in this way, the alias periods of M2, S2, and K1 constituents are found to be 62.1, 58.7, and 173 days repectively. The compatibility of the T/P and TG datasets are examined at various filtering periods. The results indicate that the low-frequency signals of the T/P data can be interpreted more safely with longer filtering periods (such as up to the maximum selected value of 200 days). When RMS errors for the 200-day low-pass filter period are compared with all 10 tidal stations, the values span the range of 2.8 to 6.7 cm. The results of a correlation analysis for this filtering period also show a strong agreement between the T/P and TG datasets across all stations investigated (e.g.,p- values consistently less than 0.001). Hence according to the analysis, the conclusion is made that the analysis of surface sea level using satellite altimeter data can be made safely with reasonably extended filtering periods such as 200 days.

关键词： sea level TOPEX/POSEIDON altimeter tide gauge

Effects of nanopores and sulfur doping on hierarchically bunched carbon fibers to protect lithium metal anode

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Carbon Energy 2021年第5期3卷 784-794页

作者： Ji In Jung Sunwoo Park son Ha Se Youn Cho Hyoung-Joon Jin young Soo Yun Program in Environmental and Polymer Engineering Inha UniversityIncheonSouth Korea KU-kiST Graduate School of Converging Science and Technology Korea UniversitySeoulSouth Korea Carbon Composite Materials Research Center Korea Institute of Science and TechnologyWanju-gunJeollabuk-doSouth Korea Department of Polymer Science and Engineering Inha UniversityIncheonSouth Korea Department of Integrative Energy Engineering Korea UniversitySeoulSouth Korea

Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a key factor to achieve their high electrochemical ***,the effects of nanopores and sulfur doping on carbon-based nanoporous host(CNH)electrode materials for LMAs were investigated using natural polymer-derived *** pore-filling behaviors of lithium metal in the nanopores of the CNH electrode materials were first observed by ex situ scanning electron microscopy analysis,where the protective lithium metal nucleation and growth process led to significantly high Coulombic efficiency(CE)of~99.4%and stable 600 *** addition,a comparison study of CNH and sulfurdoped CNH(S-CNH)electrodes,which differ only in the presence or absence of sulfur,revealed that sulfur doping can cause lower electrochemical series resistance,higher CE value,and better cycling stability in a wide range of current densities and number of ***,S-CNH-based LMAs showed high electrochemical performance in full-cell Li-S battery tests using a sulfur copolymer cathode,where a high energy density of 1370Wh kgelectrode−1 and an excellent power density of 4120Wkgelectrode−1 were obtained.

关键词： carbon template Li-S batteries lithium metal anode lithium metal batteries nanoporous carbon sulfur doping

Effects of Korean ginseng berry extract （GB0710） on penile erection： evidence from in vitro and in vivo studies

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Asian Journal of Andrology 2013年第4期15卷 503-507,I0008页

作者： Kang Su Cho Chan Woong Park Chun-ki kimt Hee young Jeon Wan Gi kim Sang Jun Lee young-Myeong kim Joo Yong Lee young Deuk Choi Department of Urology Severance Hospital Urological Science Institute Yonsei University College of Medicine Seou1120-752 Korea R&D Center Amorepacific Corporation Yongin Gyeonggi-do 446-729 Korea Vascular System Research Center and Department of Molecular and Cellular Biochemistry School of Medicine Kangwon National University Chunchon 200-701 Korea and Clinical Trial Center for Medical Devices Yonsei University College of Medicine Seoul 120-752 Korea

Several reports have promoted the root-derived Korean red ginseng （KRG; Panax ginseng） as alternative treatment for erectile dysfunction （ED）, and ginsenosides are known to be the principal active ingredients of ginseng. Recent studies showed that ginseng berries produce more ginsenosides than KRG; thus, we investigated the ability of the Korean ginseng berry extract GB0710 to relax the penile corpus cavernosum smooth muscle （CCSM） in this study. As a comparative control, the results were compared to those obtained using KRG. In addition, possible mechanisms of action for GB0710 were investigated. While KRG and GB0710 both displayed dose-dependent relaxation effects on precontracted rabbit CCSM in vitro, GB0710 was shown to be more potent than KRG. The GBO710-induced relaxation could be partially reduced by removing the endothelium. In addition, pre-treatment with several nitric oxide （NO） inhibitors significantly inhibited the relaxation of muscle strips. Furthermore, administration of GB0710 increased intracavernosal pressure （ICP） in a rat in vivo model in both a dose- and duration-dependent manner. Intracellular NO production in human microvascular endothelial cells could be induced by GB0710 and inhibited by NG-monomethyI-L-arginine. In conclusion, GB0710 had a greater relaxation effect on rabbit CCSM than did KRG extract, and increased ICP in a rat model in both a dose- and a duration-dependent manner. This relaxine effect might be mediated bv NO production.

关键词： corpus cavernosum erectile dysfunction (ED) ginseng berry nitric oxide (NO) smooth muscle

Charge transfer in graphene/polymer interfaces for CO2 detection

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Nano Research 2018年第7期11卷 3529-3536页

作者： Myungwoo son Yusin Pak Sang-Soo Chee Francis Malar Auxilia kihyeun kim Byung-Kee Lee Sungeun Lee Sun kil Kang Chaedeok Lee Jeong Soo Lee ki Kang kim Yun Hee Jang Byoung Hun Lee Gun-young Jung Moon-Ho Ham School of Materials Science and Engineering Research Institute for Solar and Sustainable Energies Gwangju Institute of Science & Technology 723 Cheomdangwagi-ro Buk-gu Gwangju 61005 Republic of Korea Materials & Devices Advanced Research Institute LG Electronics Woomyeon R&D Campus 38 Baumoe-ro Seocho-gu Seoul 06763 Republic of Korea Department of Energy and Materials Engineering Dongguk University Seoul 04620 Republic of Korea Energy Systems Engineering Daegu Gyeongbuk Institute of Science & Technology 333 Technojungang-daero Hyeonpung-myeon Dalseong-gun Daegu 42988 Republic of Korea

Understanding charge transfer processes between graphene and functional materials is crucial from the perspectives of fundamental sciences and potential applications, including electronic devices, photonic devices, and sensors. In this study, we present the charge transfer behavior of graphene and amine-rich polyethyleneimine （PEI） upon CO2 exposure, which was significantly improved after introduction of hygroscopic polyethylene glycol （PEG） in humid air. By blending PEI and PEG, the number of protonated amine groups in PEI was remarkably increased in the presence of water molecules, leading to a strong electron doping effect on graphene. The presence of CO2 gas resulted in a large change in the resistance of PEI/PEG-co-functionalized graphene because of the dramatic reduction of said doping effect, reaching a maximum sensitivity of 32% at 5,000 ppm CO2 and an applied bias of 0.1 V in air with 60% relative humidity at room temperature. This charge transfer correlation will facilitate the development of portable graphene-based sensors for real-time gas detection and the extension of the applications of graphene-based electronic and photonic devices.

关键词： graphene polyethyleneimine (PEI) polyethylene glycol carbon dioxide charge transfer