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Effects of thickness of Al thermal spray coating for STS 304

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中国有色金属学会会刊：英文版 2009年第4期19卷 925-929页

作者： Min-Su HAN Yong-Bin WOO Seok-Cheol KO young-jae jeong Seok-Ki JANG Seong-Jong KIM Division of Marine Engineering Mokpo Maritime University Chungnam Regional Innovation Agency Jeonnam Techno Park

Thermal spray coating presents a sacrificial-anode cathodic protection method since differences between the potentials of materials are *** a base metal is exposed to seawater,due to defect in the thermal spray coating,the metal is protected by the sacrificial anodic characteristics of the coating layer because micro-cells formed by the base metal and the thermal spray coating act as cathodes and anodes,*** coating thickness has little effect on the surface morphology of the ***,the electrochemical properties with the increasing of coating thickness present good results.

关键词：涂层厚度热喷涂 STS 金属接触电化学性能保护方法牺牲阳极阳极涂层

Soil texture affects the conversion factor of electrical conductivity from 1:5 soil-water to saturated paste extracts

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Pedosphere 2022年第6期32卷 905-915页

作者： Bo-Seong SEO young-jae jeong Nu-Ri BAEK Hyun-Jin PARK Hye In YANG Se-In PARK Woo-Jung CHOI Department of Rural and Bio-systems Engineering(BK21) Chonnam National UniversityGwangju 61186(Republic of Korea) Department of Renewable Resources University of AlbertaEdmontonAlberta T6G 2E3(Canada) Max Planck Institute for Biogeochemistry Jena 07745(Germany) National Institute of Environmental Research Incheon 22689(Republic of Korea) AgriBio Institute of Climate Change Management Chonnam National UniversityGwangju 61186(Republic of Korea)

Electrical conductivity(EC)of soil-water extracts is commonly used to assess soil ***,its conversion to the EC of saturated soil paste extracts(ECe),the standard measure of soil salinity,is currently required for practical *** many regression models can be used to obtain ECe from the EC of soil-water extracts,the application of a site-specific model to different sites is not straightforward due to confounding soil factors such as soil *** study was conducted to develop a universal regression model to estimate a conversion factor(CF)for predicting EC_(e) from EC of soil-water extracts at a 1:5 ratio(EC_(1:5)),by employing a site-specific soil texture(i.e.,sand content).A regression model,CF=8.9105e^(0.0106sand)/1.2984(r^(2)=0.97,P<0.001),was developed based on the results of coastal saline soil surveys(n=173)and laboratory experiments using artificial saline soils with different textures(n=6,sand content=10%-65%)and salinity levels(n=7,salinity=1-24 dS m^(-1)).Model performance was validated using an independent dataset and demonstrated that EC_(e) prediction using the developed model is more suitable for highly saline soils than for low saline *** feasibility of the regression model should be tested at other *** soil factors affecting EC conversion factor also need to be explored to revise and improve the model through further studies.

关键词： coastal saline soils electrical conductivity prediction reclaimed tideland regression model sand content saturation percentage soil salinity

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： Md Ahasan Habib Shusen Lin Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar jae-Hun jeong Jihoon Lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Potassium hydroxide

Virtual Mold Technique in Thermal Stress Analysis during Casting Process

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Journal of Materials Science & Technology 2008年第3期24卷 359-363页

作者： Si-young Kwak jae-Wook Baek jeong-Ho Nam jeong-Kil Choi E-Design Center Korea Institute of Industrial Technology Department of Virtual Engineering Korea University of Science & Technology

It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

关键词： Casting process Thermal stress analysis Virtual mold

Selective laser melting of Fe-Ni-Cr layer on AISI H13 tool steel

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中国有色金属学会会刊：英文版 2009年第4期19卷 921-924页

作者： Byeong-Don JOO jeong-Hwan JANG jae-Ho LEE young-Myung SON young-Hoon MOON School of Mechanical Engineering Pusan National University

An attempt to fabricate Fe-Ni-Cr coating on AISI H13 tool steel was performed with selective laser ***-Ni-Cr coating was produced by experimental facilities consisting of a 200 W fiber laser which can be focused to 80 μm and atmospheric chamber which can control atmospheric pressure with N2 or *** layer was fabricated with various process parameters such as laser power,scan rate and fill *** quality and coating thickness were measured and *** different surface patterns,such as typeⅠ,typeⅡand type Ⅲ,are shown with various test conditions and smooth regular pattern is obtained under the conditions as 10 μm of fill spacing,50-350 mm/s of scan rate and 40 μm of fill spacing,10-150 mm/s of scan *** maximum coating thickness is increased with power elevation or scan rate drop,and average thickness of 10 μm fill spacing is lower than that of 40 μm fill spacing.

关键词：镍铬涂层工具钢激光熔融社会扫描速度铁涂层厚度光纤激光器

Effect of Laser Parameters on Sintered Powder Morphology

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Journal of Materials Science & Technology 2010年第4期26卷 375-378页

作者： Byeong-Don Joo jeong-Hwan Jang jae-Ho Lee young-Myung Son young-Hoon Moon Engineering Research Center for Net Shape and Die Manufacturing School of Mechanical EngineeringPusan National University

Selective laser sintering is a kind of rapid prototyping process whereby a three-dimensional part is built layerwise by laser scanning a powder. This process is highly inffuenced by powder and laser parameters such as laser power, scan rate, spot size and layer thickness. Therefore a study on fabricating a line with Fe-Ni-Cr powder on AISI H13 tool steel has been performed by selective laser sintering. In this study, fabrication was performed by experimental facilities consisting of a 200W fiber laser which can be focused to 0.08 mm and atmospheric chamber which can control atmospheric pressure with argon. The line was fabricated with various laser power, scan rate and layer thickness. Line width and surface quality were investigated. With power increase or layer thickness decrease, line width was decreased and line surface quality was improved with scan rate optimization.

关键词： Selective laser sintering Direct fabrication Fiber laser

Laser surface hardening of AISI H13 tool steel

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中国有色金属学会会刊：英文版 2009年第4期19卷 917-920页

作者： jae-Ho LEE jeong-Hwan JANG Byeong-Don JOO young-Myung SON young-Hoon MOON School of Mechanical Engineering Pusan National University

An attempt was made to improve the surface hardness and wear properties of AISI H13 tool steel through solid solution hardening and refinement of microstructures using a 200 W fiber laser as a heat generating *** hardness of laser melted zone was *** order to identify the effect of heat input on the laser melting zone,scanning conditions were *** results show that,the hardness of as-received AISI H13 tool steel is approximately Hv 240,and the hardness after laser surface heat treatment is around Hv *** hardening depth and width are increased with the increase in the heat input *** of experimental results will be considered in tooling industry.

关键词：激光表面硬化工具钢 H13 激光表面热处理表面硬度信息社会光纤激光器固溶强化

Fabrication of Near Net Shape Metallic Foam via Plaster Mould

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Journal of Materials Science & Technology 2008年第3期24卷 335-339页

作者： young-Hwan Song Hwan-Goo Seon Soo-Han Parka Min-jae jeong Bo-young Hur i-Cube Center School of Nano and Advanced Materials EngineeringGyeongsang National University ERIC School of Nano and Advanced Materials EngineeringGyeongsang National University

Fabrication characteristics are unstable in direct foaming method. Therefore, most of near net-shape metallic foams are produced, and investigated by powder metallurgy. Direct foaming method, however, has many benefits （i.e. reduce the unit cost of goods and fabrication process etc.） to fabrication of metallic foams. In this article, the fabrication characteristic of near net-shape metallic foams by direct foaming method was evaluated. Al and Plaster was used for base material and mould material respectively. Ca and TiH2 were added to molten Al as thickening and blowing agent for stable condition of bubbles. Thickening time was about 10 min with a stirring speed of 600 r/min. Foaming time was 30-120 s for evaluation of the optimum foaming condition. Amount of agent was selected by pre-experimental data. Porosity of near net-shape goods was measured by Archimedes method. On the other hand, it seems that increasing poring time and thickening agent make the poor porosity

关键词： Metal foam Near net shape foam Porosity

Predictive factors for early clinical response in community-onset Escherichia coli urinary tract infection and effects of initial antibiotic treatment on early clinical response

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World Journal of Clinical Cases 2020年第19期8卷 4342-4348页

作者： young Jun Kim jeong-Mi Lee jae-Hoon Lee Department of Internal Medicine Wonkwang University College of MedicineIksan 54538South Korea Department of Public Health Wonkwang University College of MedicineIksan 54538South Korea Department of Internal Medicine and Institute of Wonkwang Medical Science Wonkwang University College of MedicineIksan 54538South Korea

BACKGROUND Urinary tract infection(UTI)is a common *** often requires hospitalization,and severe presentations,including sepsis and other complications,have a mortality rate of 6.7%-8.7%.AIM To evaluate the predictive factors for early clinical response and effects of initial antibiotic therapy on early clinical response in community-onset Escherichia coli(***)urinary tract infections(UTIs).METHODS This retrospective study was conducted at Wonkwang University Hospital in South Korea between January 2011 and December *** patients(aged>18 years)who were diagnosed with community-onset *** UTI were enrolled in this *** A total of 511 hospitalized patients were included.66.1%of the patients had an early clinical *** mean length of hospital stay in patients with an early clinical response were each 4.3 d shorter than in patients without an early clinical *** the multiple regression analysis,initial appropriate antibiotic therapy(OR=2.449,P=0.006),extended-spectrum(3-lactamase(ESBL)-producing ***(OR=2.112,P=0.044),improper use of broad-spectrum antimicrobials(OR=0.411,P=0.006),and a stay in a healthcare facility before admission(OR=0.562,P=0.033)were the factors associated with an early clinical *** broadspectrum antibiotic therapy was not associated with an early clinical *** ESBL producing ***,and the type of residence before hospital admission were the factors associated with an early clinical *** of initial antibiotic therapy was a predictive factor for an early clinical response,but broadspectrum of initial antibiotic therapy did not impact early clinical response.

关键词： Escherichia coli Urinary tract infections Adult Community acquired infections