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Plasma Science and Technology 2021年第5期23卷 96-103页

作者： Seul-Ki HAN Se-Hwan park Seong-kyu AHN Korea Atomic Energy Research Institute Yuseong-guDaejeon 34057Republic of Korea Korea Institute of Industrial Technology Yeonsu-guIncheon21999Republic of Korea

The amounts of nuclear materials in the Li Cl-KCl salt in pyroprocessing have to be analyzed to prevent the diversion of the nuclear *** alternative method to the chemical analysis has been pursued,and laser-induced breakdown spectroscopy(LIBS)is one *** the present work,an in situ and quantitative analysis method of electro-recovery(ER)salt was proposed and demonstrated by using LIBS combined with dipstick *** types of simulated salt samples were prepared:ER salt sample and salt obtained from the dipstick sampling,and pulsed neodymium-doped yttrium aluminum garnet(Nd:YAG)laser with a wavelength of 532 nm was focused on the salt to generate *** plasma emission was measured by using an Echelle spectrometer with a resolution of 0.01 nm in conjunction with an Intensified Charge-Coupled Detector *** U and other rare earth peaks in the spectra were *** best Limit of Detection and Root Mean Square Error of Calibration of U were 38 ppm and 0.0203 wt%,*** work shows that the U in the pyroprocessing ER salt can be monitored with LIBS.

关键词： LIBS uranium LOD RMSEC

Multiplanar reformations and minimum intensity projections using multi-detector row CT for assessing anomalies and disorders of the pancreaticobiliary tree

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World Journal of Gastroenterology 2007年第31期13卷 4177-4184页

作者： Hyun Cheol Kim Dal Mo Yang Wook jin Chang Woo Ryu Jung kyu Ryu Sung Il park Seong jin park Hyeong Cheol Shin Il Young Kim Department of Radiology East-West Neo Medical Center Kyung-Hee University Seoul Republic of Korea Department of Diagnostic Radiology Kwandong University Myongji Hospital Goyang Republic of Korea Department of Diagnostic Radiology Soonchunhyang University Bucheon Hospital Bucheon Republic of Korea Department of Diagnostic Radiology Soonchunhyang University Cheonan Hospital Cheonan Republic of Korea

CT scan is regarded as the imaging modality of choice in patients with pancreaticobiliary ductal abnormalities. However, the axial orientation of the CT images provides only limited anatomical view of pancreaticobiliary ductal abnormalities. The technological advances of multi-de-tector row CT and three-dimensional image processing in workstations allows rapid image acquisition and a short postprocessing time. In particular, multiplanar reforma-tions (MPR) and minimum intensity projections (MinIP) offer rapid and accurate images of the anatomy and ab-normalities of the pancreaticobiliary tree. Moreover, MPR and MinIP help determine the relationship between the pancreaticobiliary ductal anatomy and the surrounding structures. This pictorial review illustrates the wide spec-trum of images obtained by the MPR and MinIP of the anomalies and disorders of the pancreaticobiliary tree.

关键词： Multi-detector CT Bile Ducts Biliary System Pancreas Computer Applications-3D

Highly efficient reduction of aqueous Cr(VI) with novel ZnO/SnS nanocomposites through the piezoelectric effect

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Journal of Environmental Sciences 2022年第8期34卷 57-66页

作者： Hao Sun Soo-jin park Department of Chemistry and Chemical Engineering Inha UniversityIncheon 22212South Korea

In this work, novel ZnO/SnS nanocomposites were successfully synthesized via a hydrothermal approach, which is developed for piezoelectric catalytic reduction of hexavalent chromium(Cr(VI)) in an aqueous solution. The constructed ZnO/SnS nanocomposites exhibited higher catalytic efficiency for Cr(VI) reduction under a mechanical force(e.g., ultrasonic vibration) compared to pristine ZnO and SnS. In particular, the ZnO/SnS(with 30 wt.% of SnS) heterojunctions revealed an optimal degradation activity among all the prepared samples, which completely removed the Cr(VI)(20 mg/L) solution within 35 min. Moreover, the piezoelectric catalytic activity of ZnO/SnS remained stable after four consecutive cycling experiments. The results of the morphology observations indicated that the SnS nanoparticles adhere to the surface of the ZnO nanorods. The improved piezoelectric catalytic performance of the ZnO/SnS heterojunctions can be attributed to the formation of an intimate interfacial between ZnO and SnS, which effectively inhibits the electron-hole recombination and speeds up the rate of charge transfer. The study reveals a new design of ZnO/SnS heterojunctions as a high-performance and eco-friendly piezoelectric catalyst and provides a promising strategy for addressing environmental problems and energy crises.

关键词： Cr(VI)reduction ZnO/SnS Piezoelectric effect

Fabrication of cast carbon steel with ultrafine TiC particles

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 54-57页

作者： Sang-Hoon LEE jin-Ju park Sung-Mo HONG Byoung-Sun HAN Min-Ku LEE Chang-kyu RHEE Nuclear Materials Research Division Korea Atomic Energy Research Institute Daejeon 305-353 Korea

The carbon steels dispersed with ultrafine TiC particles were fabricated by conventional casting method. The casting process is more economical than other available routes for metal matrix composite production, and the large sized components to be fabricated in short processing time. However, it is extremely difficult to obtain uniform dispersion of ultrafine ceramic particles in liquid metals due to the poor wettability and the specific gravity difference between the ceramic particle and metal matrix. In order to solve these problems, the mechanical milling (MM) and surface-active processes were introduced. As a result, Cu coated ultrafine TiC powders made by MM process using high energy ball milling machine were mixed with Sn powders as a surfactant to get better wettability by lowering the surface tension of carbon steel melt. The microstructural investigations by OM show that ultrafine TiC particles are distributed uniformly in carbon steel matrix. The grain sizes of the cast matrix with ultrafine TiC particles are much smaller than those without ultrafine TiC particles. This is probably due to the fact that TiC particles act as nucleation sites during solidification. The wear resistance of cast carbon steel composites added with MMed TiC/Cu-Sn powders is improved due to grain size refinement.

关键词： TiC particles mechanical milling carbon steel casting dispersion wettability

Impact of uneven distribution of grain characteristics on yield strength and martensitic transformation of as-hot-rolled medium-entropy alloys

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Journal of Materials Science & Technology 2024年第10期177卷 234-245页

作者： Jungwan Lee Hyojin park Sujung Son Jae Wung Bae jin You Kim Sung kyu Kim Jae-il Jang Hyoung Seop Kim Department of Materials Science and Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Metallurgical Engineering Pukyong National UniversityBusan 48513Republic of Korea Technical Research Laboratories Energy and Shipbuilding Steel Research GroupPOSCOPohangRepublic of Korea Division of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Graduate Institute of Ferrous&Eco Materials Technology(GIFT) Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Center for Heterogenic Metal Additive Manufacturing Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Advanced Institute for Materials Research(WPI-AIMR) Tohoku UniversitySendai 980-8577Japan

As-hot-rolled medium-entropy alloys(MEAs)with unevenly distributed grain sizes of face-centered cubic grains exhibit better yield strength without uniform elongation loss compared to cold-rolled and an-nealed *** operation of dynamic recrystallization(DRX)during several hot rolling passes leads to a wide range of grain sizes from submicrons to tens of micrometers due to the grain growth after nucleation:early recrystallized grains are coarser than recently recrystallized *** only the grain size but internal dislocation density of the recently recrystallized grain is *** the tensile deformation of the hot-rolled MEAs at-196 ℃,dislocation pile-ups in the relatively soft and fine DRX grains enhance yield stress and hetero-deformation-induced strain *** to the enhanced yield stress of the as-hot-rolled MEAs,stress-induced martensitic transformation easily ***,partially DRXed MEAs hot-rolled at 800 ℃ have lower yield stress than fully DRXed ones,hot-rolled at 900 and 1000 ℃.This is attributed to the softening effect of the stress-induced body-centered cubic martensitic transformation in unrecrystallized coarse grains prior to the yielding,which lowers the yield stress of the partially DRXed *** yielding,the martensitic transformation facilitates strain hard-ening and early necking is *** study presents a fresh outlook on the uneven distribution of grain sizes by hot rolling beneficial to mechanical responses of uniform elongation of~45%despite the as-rolled states with an advantage of simplified thermo-mechanical processes.

关键词： Dynamic recrystallization Nucleation and growth Heterogeneity Grain size distribution Deformation-induced martensitic transformation

Amine functionalization on thermal and mechanical behaviors of graphite nanofibers-loaded epoxy composites

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Journal of Materials Science & Technology 2023年第20期151卷 80-88页

作者： Seong-Hwang Kim Sang-jin park Seul-Yi Lee Soo-jin park Department of Chemistry Inha University100 InharoIncheon 22212the Republic of Korea

With the growing demand for faster and more powerful computing,effective heat dissipation is essential to ensure the longevity,reliability,and high performance of electronic *** the field of modern electronic packaging materials,there is a great need for graphitic material-loaded polymeric composites(GPCs)with excellent thermal ***,the enhancement efficiency of GPCs is hindered by the agglomeration of fillers and the interfacial thermal resistance caused by the lack of continuous thermally conductive pathways between the filler and *** the interfaces between filler and matrix is of great importance in optimizing the performances of ***,we fabricated graphite nanofibers(GNF)-loaded nanocomposites using acid-functionalized GNF(AGNF)and acidtetraethylenepentamine-functionalized(TGNF)as a filler and epoxy resin as a matrix with different GNF loading contents to explore the interfacial properties of the *** optimal GNF loading for AGNF was 0.5 wt.%,while the TGNF showed 0.75 wt.%.The highest thermal conductivity(0.51 W m^(−1) K^(−1))and fracture toughness(25.8 MPa m^(1/2))values were found in the TGNF-loaded nanocomposites with a fraction of 0.75 wt.%,representing enhancements of∼145%and∼400%,respectively,compared to those of neat *** experimental data presented herein demonstrate that the interfacial properties play a significant role in enhancing the thermal and mechanical performances of the *** present approach is expected to serve as a valuable tool in the design of conductive polymeric nanocomposites for further practical applications,such as thermal interface materials and packaging of high-power electric devices.

关键词： Graphite nanofiber Nanocomposites Interfacial interaction Thermal conductivity Fracture resistance

Bleeding after endoscopic papillectomy and its risk factors:A single center experience of 196 cases

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Hepatobiliary & Pancreatic Diseases International 2024年第6期23卷 613-619页

作者： jin Ho Choi Won Chul Kim Joo kyung park Jong kyun Lee kyu Taek Lee Kwang Hyuck Lee Department of Medicine Division of GastroenterologySamsung Medical CenterSungkyunkwan University School of MedicineSeoul 06351Korea

Background:Endoscopic papillectomy(EP)is an effective method to remove an ampulla of Vater(AoV)adenoma with minimal *** reviewed the clinical outcomes and prognosis of patients undergoing EP,including tumor recurrence and adverse ***:A total of 196 patients who underwent EP from January 2004 to December 2017 were *** information was collected through electronic medical records,and risk factors to predict postprocedural bleeding were analyzed using a multivariate logistic regression ***:A total of 93.9%patients(184/196)underwent complete *** the follow-up period,14.7%patients(27/184)experienced tumor recurrence,and two of seven surgically resected tumors were malignant.A total of 45.4%patients(89/196)experienced adverse events related to *** bleeding occurred in 16.3%of the patients(32/196),and they were all successfully treated with endoscopic hemostasis and conservative *** most frequent site of delayed bleeding was the distal end of the papillary orifice,and 56.3%(18/32)patients of delayed bleeding were classified as having mild severity,the others had moderate *** adenomatous polyposis(FAP)[odds ratio(OR)=3.80,95%confidence interval(CI):1.01-14.29;P<0.05]and male sex(OR=2.82,95%CI:1.04-7.63;P=0.04)showed statistical significance in predicting delayed post-EP ***:EP for AoV adenoma was a highly effective and safe *** risk of post-EP delayed bleeding was increased in patients with FAP syndrome and male patients,and post-EP bleeding occurred most commonly in the distal part of the AoV.

关键词： Ampullary neoplasm Endoscopic papillectomy Post-procedural bleeding Risk factor

Role of oxygen free radicals in patients with acute pancreatitis

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World Journal of Gastroenterology 2003年第10期9卷 2266-2269页

作者： Byung kyu park Jae Bock Chung jin Heon Lee Jeong Hun Suh Seung Woo park Si Young Song Hyeyoung Kim kyung Hwan Kim jin kyung Kang Department of Internal Medicine Institute of GastroenterologyCollege of MedicineYonsei UniversitySeoulKorea Department of Pharmacology College of MedicineYonsei UniversitySeoulKorea Departmentof Internal Medicine Institute of GastroenterologyCollege of MedicineYonsei UniversitySeoulKorea

AIM:The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis. METHODS:The plasma levels of C-reactive protein(CRP), lipid peroxide(LPO),myeloperoxidase(MPO)and superoxide dismutase(SOD)were measured in 13 patients with acute pancreatitis and 14 healthy volunteers. RESULTS:Among the patients with acute pancreatitis,there were higher plasma levels of LPO and MPO and lower SOD activity in patients with severe pancreatitis than in those with mild ***,there was no significant difference in the serum marker of oxidative stress no matter what the etiology *** LPO level was especially correlated with the concentration of serum CRP and CT severity index. CONCLUSION:The oxygen free radicals may be closely associated with inflammatory process and the severity of acute ***,the concentration of plasma LPO is a meaningful index for determining the severity of the disease.

关键词： Oxidative Stress Severity of Illness Index Acute Disease Adult Aged Female Humans Lipid Peroxides Male Middle Aged Pancreatitis Peroxidase Predictive Value of Tests Prognosis Reactive Oxygen Species Superoxide Dismutase

Small RNA- and DNA-based gene therapy for the treatment of liver cirrhosis, where we are?

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World Journal of Gastroenterology 2014年第40期20卷 14696-14705页

作者： kyung-Hyun Kim Kwan-kyu park Department of Pathology College of Medicine Catholic University of Daegu Daegu 705-718 South Korea

Chronic liver diseases with different aetiologies rely on the chronic activation of liver injuries which result in a fibrogenesis progression to the end stage of cirrhosis and liver *** on the underlying cellular and molecular mechanisms of a liver fibrosis,there has been proposed several kinds of approaches for the treatment of liver ***,liver gene therapy has been developed as an alternative way to liver transplantation,which is the only effective therapy for chronic liver *** activation of hepatic stellate cells,a subsequent release of inflammatory cytokines and an accumulation of extracellular matrix during the liver fibrogenesis are the major obstacles to the treatment of liver *** targeted strategies have been developed,such as antisense oligodeoxynucleotides,RNA interference and decoy oligodeoxynucleotides to overcome this *** this report an overview will be provided of targeted strategies for the treatment of liver cirrhosis,and particularly,of the targeted gene therapy using short RNA and DNA segments.

关键词： Liver cirrhosis Gene therapy Oligodeoxynucleotides Antisense Small interfering RNA Micro RNA Decoy

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