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Prominent cycling reversibility and kinetics enabled by CaTiO3 protective layer on Zn metal for aqueous Zn-ion batteries

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Journal of Energy Chemistry 2025年第1期100卷 245-258页

作者： Gaeun Lee Yong Nam Ahn Seongjoon So Chanwoo park Jong-Seong Bae taehyun park Il tae Kim Jaehyun Hur School of Chemical Biological and Battery Engineering Gachon University Seongnam Busan Center Korea Basic Science Institute

Aqueous Zn-ion batteries （AZIBs） have received considerable attention owing to their various advantages such as safety,low cost,simple battery assembly conditions,and high ionic ***,they still suffer from serious problems,including uncontrollable dendrite growth,corrosion,hydrogen evolution reaction （HER） from water decomposition,electrode passivation,and unexpected *** creation of a uniform artificial nanocrystal layer on the Zn anode surface is a promising strategy for resolving these ***,we propose the use of a perovskite CaTiO3（CTO） protective layer on Zn（CTO@Zn） as a promising approach for improving the performance of *** CTO artificial layer provides an efficient pathway for Zn ion diffusion towards the Zn metal because of the high dielectric constant （εr=180） and ferroelectric characteristics that enable the alignment of dipole moments and redistribute the Zn2+ions in the CTO *** avoiding the direct contact of the Zn anode with the electrolyte solution,the uneven dendrite growth,corrosion,parasitic side reactions,and HER are mitigated,while CTO retains its mechanical and chemical robustness during ***,CTO@Zn demonstrates an improved lifespan in a symmetric cell configuration compared with bare ***@Zn shows steady overpotential （～68 m V） for 1500 h at 1 mA cm-2/0.5 mA h cm-2,excelling bare ***,when paired with the V2O5-C cathode,the CTO@Zn//V2O5-C full battery delivers 148.4 mA h g-1（based on the mass of the cathode） after 300 *** study provides new insights into Zn metal anodes and the development of high-performance AZIBs.

关键词： Artificial layer Dielectric constant Zn metal anode Zinc aqueous battery

Influence of the electrolyte conductivity on the critical current density and the breakdown voltage

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Chinese Journal of Chemical Engineering 2023年第7期59卷 169-175页

作者： Hae-Kyun park Dong-Hyuk park bum-Jin Chung Department of Nuclear Engineering Kyung Hee University 1732 Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 17104Korea

The work investigates influence of the electrolyte conductivity on the onset of partial contact glow discharge electrolysis(CGDE)in a water *** current density(CCD)and breakdown voltage were measured together with in situ observation of hydrogen bubble behavior,whose influence has not been focused *** a fixed current during normal electrolysis,hydrogen coalescence adjacent to cathode surface was invigorated at a lower *** analyses elucidated the hydrogen coalescence characteristics by quantifying size and population of detached hydrogen *** CCD increased about 104% within given range of conductivity(11.50-127.48 mS·cm^(-1))due to impaired bubble coalescence,which delays hydrogen film formation on the ***,decreasing trend of breakdown voltage was measured with increased conductivity showing maximum drop of 74%.It is concluded that onset of partial CGDE is directly affected by hydrodynamic bubble behaviors,whereas the electrolyte conductivity affects the bubble formation characteristics adjacent to cathode electrode.

关键词： Water electrolysis Critical current density Breakdown voltage Electrolyte conductivity Hydrogen bubble behavior

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A Study of the Influence of Air-knife Tilting on Coating Thickness in Hot-dip Galvanizing

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Journal of Thermal Science 2009年第3期18卷 262-267页

作者： tae-Seok CHO Young-Doo KWON Soon-bum KWON School of Mechanical Engineering Kyungpook National University

Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashing. The progress of industry demands continuously the reduction of production costs which may relate directly with the increase of coating speed, and the speed up of coating results in the increase of stagnation pressure in gas wiping system in final. It is known that the increase of stagnation pressure may accompany a harmful problem of splashing in general. Together with these, also, from the view point of energy consumption, it is necessary to design a nozzle optimally. And there is known that the downward tilting of nozzle using in air knife system is effective to prevent in somewhat the harmful problem of splashing. In these connections, first, we design a nozzle with constant expansion rate. Next, for the case of actual coating conditions in field, the effects of tilting of the constant expansion rate nozzle are investigated by numerical analysis. Under the present numerical conditions, it was turned out that the nozzle of constant expansion rate of p = having a downward jet angle of 5^0 is the most effective to diminish the onset of splashing, while the influence of small tilting of the nozzle on impinging wall pres- sure itself is not so large.

关键词： Air-knife Constant expansion rate nozzle Impinging pressure Wall shear stress Hot-dip galvanizing Coating thickness Splashing

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Integrated guidance and control for damping augmented system via convex optimization

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Chinese Journal of Aeronautics 2022年第7期35卷 30-39页

作者： Bong-Gyun park tae-Hun KIM The 1^(st)R&D Institute-4 Agency for Defense DevelopmentDaejeon 34186Republic of Korea

In this paper,an integrated guidance and control approach is presented to improve the performance of the missile *** approach includes damping augmented system with attitude rate feedback to decrease the oscillation during the homing phase for missiles with low *** addition,physical constraints,which can affect the performance of the missile interception,such as acceleration limit,seeker’s look angle,and look angle rate constraints are *** integrated guidance and control problem is formulated as a convex quadratic optimization problem with equality and inequality constraints,and the solution is obtained by a primal–dual interior point *** performance of the proposed method is verified through several numerical examples.

关键词： Convex optimization Damping augmented system Integrated guidance and control Physical constraint Primal-dual interior point method

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Rapidly growing primary anal canal lymphoma:a case report and literature review

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Gastroenterology Report 2023年第1期11卷 582-584页

作者： Yu Kyung Chung Su bum park Department of Internal Medicine Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and TechnologyPusan National University Yangsan HospitalYangsanRepublic of Korea

Introduction Anal cancer is a rare cancer accounting for2%of all gastrointestinal tract malignancies[1].Among anal cancers,squamous cell cancer(SCC)is the most common and lymphoma is one of the least *** gastrointestinal tract is the most common site for extranodal non-Hodgkin’s lymphoma(NHL),and diffuse large B-cell lymphoma(DLBCL)is the most common histologic ***,primary colorectal lymphoma accounts for only 0.3%of all large intestinal malignancies and3%of all gastrointestinal lymphomas[2].Anal canal SCC and lymphomas are treated differently;thus,accurate diagnosis is crucial.

关键词： lymphoma gastrointestinal diagnosis

Somatostatin adjunctive therapy for non-variceal upper gastrointestinal rebleeding after endoscopic therapy

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World Journal of Gastroenterology 2011年第29期17卷 3441-3447页

作者： Cheol Woong Choi Dae Hwan Kang Hyung Wook Kim Su bum park Kee tae park Gwang Ha Kim Geun Am Song Mong Cho Department of Internal Medicine Pusan National University School of Medicine and Medical Research InstituteYangsan-siGyeongsangnam-do 626-770South Korea

AIM:To evaluate the effect of pantoprazole with a somatostatin adjunct in patients with acute non-variceal upper gastrointestinal bleeding(NVUGIB).METHODS:We performed a retrospective analysis of a prospective database in a tertiary care university *** October 2006 to October 2008,we enrolled 101 patients with NVUGIB that had a high-risk stigma on *** 24 h of hospital admission,all patients underwent endoscopic *** successful endoscopic hemostasis,all patients received an 80-mg bolus of pantoprazole followed by continuous intravenous infusion(8 mg/h for 72 h).The somatostatin adjunct group(n=49)also received a 250-μg bolus of somatostatin,followed by continuous infusion (250μg/h for 72 h).Early rebleeding rates,disappearance of endoscopic stigma and risk factors associated with early rebleeding were ***:Early rebleeding rates were not significantly different between treatment groups(12.2%vs 14.3%,P=0.766).Disappearance of endoscopic stigma on the second endoscopy was not significantly different between treatment groups(94.2%vs 95.9%,P=0.696).Multivariate analysis showed that the complete Rockall score was a significant risk factor for early rebleeding(P =0.044,OR:9.080,95%CI:1.062-77.595).CONCLUSION:The adjunctive use of somatostatin was not superior to pantoprazole monotherapy after successful endoscopic hemostasis in patients with NVUGIB.

关键词： Somatostatin Pantoprazole Gastrointestinal bleeding Rebleeding

Effects of design parameters and tension on behavior of a coil using finite element analysis

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Journal of Iron and Steel Research International 2018年第9期25卷 883-891页

作者： Kyu-tae parkI Hyun-chul park Department of Mechanical Engineering Pohang Universityof Science and Technology Pohang Gyeongbuk 790-784Korea

During the thin strip coiling process, it is necessary to use a sleeve with a mandrel to prevent excessive deformation of the strip. Stress distribution in the sleeve and in the strip is an important factor that determines the quality of the coil. However, owing to the accumulation of high pressure, it is difficult to determine the stress distribution through experimentation. Thus, stress analysis of the strip coiling process was conducted. Finite element analysis was used to investigate the effects of the weight of the strip and the mandrel on the stress distribution and stress concentration near the starting point of the coil. The radial stress was predicted for a coil with a stacked thickness of 384 mm, which corresponds to a strip length of 1486 m, using the stress analysis model developed in a preceding research. A method was presented to reduce the weight and radial stress of a strip coil. It was found that the deformation of the sleeve can be reduced by decreasing the gap between the mandrel segments. The thickness of the sleeve can be reduced from 120 to 106 mm using the stress analysis results. Furthermore, coiling tension can be reduced by 44% compared to the existing value considering the interlayer slip of the strip coil.

关键词： Strip coiling process Structural analysis Finite element method Mandrel Coiling tension

Recent advances in endoscopic retrograde cholangiopancreatography in Billroth II gastrectomy patients: A systematic review

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World Journal of Gastroenterology 2019年第24期25卷 3091-3107页

作者： tae Young park tae Jun Song Department of Internal Medicine Inje University Seoul Paik HospitalSeoul 04551South Korea Division of Gastroenterology Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 138-736South Korea

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)in patients with Billroth Ⅱ gastrectomy has been considered a challenging procedure due to the surgically altered gastrointestinal ***,there has been a paucity of comparative studies regarding ERCP in Billroth Ⅱ gastrectomy cases because of procedure-related morbidity and mortality and practical and ethical *** systematic and comprehensive review was performed to obtain a recent perspective on ERCP in Billroth Ⅱ gastrectomy *** To systematically review the literature regarding ERCP in Billroth Ⅱ gastrectomy *** A systematic review was performed on the literature published between May 1975 and January *** following electronic databases were searched:PubMed,EMBASE,and Cochrane *** outcomes of successful afferent loop intubation and successful selective cannulation and occurrence of adverse events were *** A total of 43 studies involving 2669 patients were *** study designs were 36(83.7%)retrospective cohort studies,4(9.3%)retrospective comparative studies,2(4.7%)prospective comparative studies,and 1(2.3%)prospective cohort *** a total of 2669 patients,there were 1432 cases(55.6%)of sideviewing endoscopy,664(25.8%)cases of forward-viewing endoscopy,171(6.6%)cases of balloon-assisted enteroscopy,169(6.6%)cases of anterior obliqueviewing endoscopy,64(2.5%)cases of dual-lumen endoscopy,31(1.2%)cases of colonoscopy,and 14(0.5%)cases of multiple bending *** overall success rate of afferent loop intubation was 91.3%(2437/2669),and the overall success rate of selective cannulation was 87.9%(2346/2437).A total of 195 cases(7.3%)of adverse events *** success rates of afferent loop intubation and the selective cannulation rate for each type of endoscopy were as follows:side-viewing endoscopy 98.2%and 95.3%;forward-viewing endoscopy 97.4%and 95.2%;balloon-assisted enteroscopy 95.4%and 97.5%;oblique-viewing endosco

关键词： Endoscopic retrograde Cholangiopancreatography Therapeutic Endoscope Billroth Ⅱ operation Adverse event Systematic review

Changes in endoscopic patterns before and during COVID-19 outbreak:Experience at a single tertiary center in Korean

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World Journal of Clinical Cases 2021年第15期9卷 3576-3585页

作者： Kook Hyun Kim Sung bum Kim tae Nyeun Kim Division of Gastroenterology and Hepatology Department of Internal MedicineYeungnam University College of MedicineDaegu 42415South Korea

BACKGROUND The surge of coronavirus disease 2019(COVID-19)patients has markedly influenced the treatment policies of tertiary hospitals because of the need to protect medical staff and contain viral transmission,but the impact COVID-19 had on emergency gastrointestinal endoscopies has not been *** To compare endoscopic activities and analyze the clinical outcomes of emergency endoscopies performed before and during the COVID-19 outbreak in Daegu,the worst-hit region in South *** This retrospective cohort study was conducted on patients aged≥18 years that underwent endoscopy from February 18 to March 28,2020,at a tertiary hospital in ***,laboratory findings,types and causes of emergency endoscopies,and endoscopic reports were reviewed and compared with those obtained for the same period in 2018 and *** From February 18 to March 28,a total of 366 emergent endoscopic procedures were performed:Upper endoscopy(170,50.6%),endoscopic retrograde cholangiopancreatography(113,33.6%),and colonoscopy with sigmoidoscopy(53,15.8%).The numbers of procedures performed in 2018 and 2019 dropped by 48.8%and 54.8%,respectively,compared with those in *** the COVID-19 outbreak,the main indications for endoscopy were melena(36.7%),hematemesis(30.6%),and hematochezia(10.2%).Of the endoscopic abnormalities detected,gastrointestinal bleeding was the most common:39 cases in 2018,51 in 2019,and 35 in *** The impact of COVID-19 is substantial and caused dramatic reductions in endoscopic procedures and changes in patient ***-term follow-up studies are required to determine the effects of COVID-19 induced changes in the endoscopy field.

关键词： COVID-19 Coronavirus Endoscopy Emergency endoscopy