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Journal of Thermal Science 2012年第1期21卷 82-87页

作者： Yoon Hwan Choi Yeon Won Lee kwang Choi Deog hee Doh Kyoung Joon Kim Department of mechanical and Automotive Engineering Pukyong National University Steel Structure Research Division Research Institute of Industrial Science & Technology Division of mechanical and information Engineering Korea Maritime University

Line heating method is widely used to manufacture curved surfaces in ship building. The main factors governing the quality of the manufactured products are the moving velocity of the heating source, heating strength, and heating ways. In this study, the temperature distributions of the heated plate were investigated with the condition that the line heating process was automatic. The temperature variations were also investigated with the changes of those three variables. The numerical results showed that the peak temperature decreased as the moving velocity of the heating source increased. It also revealed that the peak temperatures changed linearly with the changes of the heating source.

关键词： moving heat source Line heating Thermal stress Residual deformation Conductive heat transfer

Role of debris flow on the change of^10Be concentration in rapidly eroding watersheds:a case study on the Seti River,central Nepal

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Journal of mountain Science 2017年第4期14卷 716-730页

作者： KIm Dong Eun SEONG Yeong Bae CHOI kwang hee YU Byung Yong Dept.of Geography Korea UniversitySeoul 02841Korea Yeongsan River Basin Environmental Office Ministry of EnvironmentGwangju 61945Korea Korea Institute of Science and Technology Seoul 02792Korea

The concentration of cosmogenic loBe in riverine sediments has been widely used as a proxy for catchment-wide denudation rate （CWDR）. One of the key assumptions of this approach is that sediments originating from sub-basins with different erosional histories are well mixed. A tragic debris flow occurred in the Seti River watershed, central Nepal, on may 5, 2012. This catastrophic debris flow was triggered by slope failure on the peak of Annapurna IV and resulted in many casualties in the lower Seti Khola. However, it provided an opportunity to test the assumption of equal mixing of sediments in an understudied rapidly eroding watershed. This study documents the CWDR of ^10Be to evaluate the extent of the influence of episodic erosional processes such as debris flow on the spatio-temporal redistribution of loBe concentrations. Our data show that the debris flow caused little change in CWDR across the debris flow event. In addition to isotopic measurement, we calculated denudation rates by using the modeled concentrations in pre- and post-landslide sediments based on the local ^10Be production rate. The modeled result showed little change across the event, indicating that the debris flow in may 2012 played a minor role in sediment evacuation, despite the rapid erosion in the catchment. Our study concludes that although the 2012 event caused many casualties and severe damage, it was a low-magnitude, high frequency event.

关键词： Seti River Beryllium-10 (^10Be) Catchment-wide denudation rate (CWDR) Debrisflow Episodic erosional processes

Performance of a New Ion Source for KSTAR Tokamak Plasma Heating

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Plasma Science and Technology 2014年第6期16卷 620-624页

作者： Tae-Seong KIm Seung Ho JEONG Doo hee CHANG kwang Won LEE Sang-Ryul IN Korea Atomic Energy Research Institute

In the experimental campaign of 2010 and 2011 on KSTAR, the NBI-1 system was equipped with one prototype ion source and operated successfully, providing a neutral beam power of 0.7-1.6 mW to the tokamak plasma. The new ion source planned for the 2012 KSTAR campaign had a much more advanced performance compared with the previous one. The target performance of the new ion source was to provide a neutral deuterium beam of 2 mW to the tokamak plasma. The ion source was newly designed, fabricated, and assembled in 2011. The new ion source was then conditioned up to 64 A/100 keV over a 2-hour beam extraction and performance tested at the NB test stand （NBTS） at the Korea Atomic Energy Research Institute （KAERI） in 2012. The measured optimum perveance at which the beam divergence is a minimum was about 2.5μP, and the minimum beam divergent angle was under 1.0° at 60 keV. These results indicate that the 2.0 mW neutral beam power at 100 keV required for the heating of plasma in KSTAR can be delivered by the installation of the new ion source in the KSTAR NBI-1 system.

关键词： NBI ion source KSTAR neutral beam plasma heating positive based ion

Artificial photosynthesis for high-value-added chemicals:Old material,new opportunity

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Carbon Energy 2022年第1期4卷 21-44页

作者： Sungsoon Kim kwang hee Kim Cheoulwoo Oh Kan Zhang Jong Hyeok Park Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoulRepublic of Korea Institute of Optoelectronics&Nanomaterials Nanjing University of Science and TechnologyNanjingChina

Solar energy utilization has drawn attention due to ever-increasing environmental and energy ***(PEC)and photocatalytic(PC)water splitting for hydrogen production,which is the most popular and well-established solar-to-chemical conversion process,has been studied thoroughly to date but is now facing limitations related to low conversion *** resolve this issue,research in PEC cells or photocatalysts has recently aimed to produce alternative value-added chemicals by modifying their redox reactions,which potentially enables high economic reward to compensate for the low ***,various kinds of redox reactions that decouple classic water splitting reactions to produce value-added chemicals via PEC and PC processes are *** coupling of CO_(2) reduction,O_(2) reduction and organic synthesis with either water oxidation or water reduction is comprehensively discussed from the perspective of basic fundamental and product selectivity in terms of the band structure of materials,cocatalyst design,and thermodynamics and kinetics of the *** the review,future challenges and opportunities are suggested with respect to the redesigned artificial synthesis,which might be an alternative development for the commercialization of PEC or PC value-added chemical production technologies in the near future.

关键词： artificial photosynthesis photocatalysts photoelectrochemical cells redox reactions value-added chemical production

Collapse behavior evaluation of hybrid thin-walled member by stacking condition

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Transactions of Nonferrous metals Society of China 2011年第A01期21卷 135-140页

作者： Kil-Sung LEE Hyeon-Kyeong SEO Yong-June YANG Woo-Chae HWANG kwang-hee Im In-Young YANG R&D Center Dacc LTD. 948-13 Dunsan-ri Bongdong-eup Wanju-gun Jeonbuk 565-902 Korea Departments of Advanced Parts and materials Engineering Graduate School Chosun University Department of Automotive Engineering Woosuk University Departments of mechanical Design Engineering Chosun University

The recent trend of vehicle design aims at crash safety and environmentally-friendly aspect. For the crash safety aspect, the energy absorbing members should absorb collision energy sufficiently but for the environmentally-friendly aspect, the vehicle structure must be light weight in order to improve the fuel efficiency and reduce the tail gas emission. Therefore, the light weight of vehicle must be achieved in a securing safety status of crash. An aluminum or carbon fiber reinforced plastics (CFRP) is representative one of the light-weight materials. Based on the respective collapse behavior of aluminum and CFRP member, the collapse behavior of hybrid thin-walled member was evaluated. The hybrid members were manufactured by wrapping CFRP prepreg sheets outside the aluminum hollow members in the autoclave. Because the CFRP is an anisotropic material whose mechanical properties, such as strength and elasticity, change with its stacking condition, the effects of the stacking condition on the collapse behavior evaluation of the hybrid thin-walled member were tested. The collapse mode and energy absorption capability of the hybrid thin-walled member were analyzed with the change of the fiber orientation angle and interface number.

关键词： collapse behavior aluminum and CFRP hybrid thin-walled member stacking condition

Reciprocating friction characteristics of magneto-rheological fluid for aluminum under magnetic field

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Transactions of Nonferrous metals Society of China 2014年第1期24卷 171-176页

作者：张鹏 kwang-heeLEE Chul-heeLEE Department of mechanical Engineering Inha University

Reciprocating friction characteristics of magneto-rheological （mR） fluid for aluminum under a magnetic field at different loads and oscillation frequencies were studied when mR fluids were worked in reciprocating motions such as in dampers for automobiles, and surface polishing and other finishing. Thus, experiments were carried out to evaluate the reciprocating friction characteristic of mR fluid for aluminum. The obtained data from the tests are sorted in groups depending on various loads and oscillation frequencies, to analyze the relationship between test condition and travel cycle. Surfaces of specimens were compared by measuring the surface roughness and observing the surface images. The performance of reciprocating friction characteristics of mR fluid for aluminum is evaluated through analyzing the experiment results.

关键词： magneto-rheological fluid reciprocating friction aluminum magnetic field smart material

Design of an 8 bit differential paired eFuse OTP memory IP reducing sensing resistance

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Journal of Central South University 2012年第1期19卷 168-173页

作者： JANG Ji-Hye 金丽妍 JEON Hwang-Gon KIm kwang-Il HA Pan-Bong KIm Young-hee Department of Electronic Engineering Changwon National University9 Sarim-DongChangwon 641-773Korea

For the conventional single-ended eFuse cell, sensing failures can occur due to a variation of a post-program eFuse resistance during the data retention time and a relatively high program resistance of several kilo ohms. A differential paired eFuse cell is designed which is about half the size smaller in sensing resistance of a programmed eFuse link than the conventional single-ended eFuse cell. Also, a sensing circuit of sense amplifier is proposed, based on D flip-flop structure to implement a simple sensing circuit. Furthermore, a sensing margin test circuit is proposed with variable pull-up loads out of consideration for resistance variation of a programmed eFuse. When an 8 bit eFuse OTP IP is designed with 0.18 ~tm standard CmOS logic of TSmC, the layout dimensions are 229.04 μm ×100.15μm. All the chips function successfully when 20 test chips are tested with a program voltage of 4.2 V.

关键词： eFuse differential paired efuse cell one time programmable memory sensing resistance D flip-flop based sense amplifier

Discharge Characteristics of Large-Area High-Power RF Ion Source for Positive and Negative Neutral Beam Injectors

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Plasma Science and Technology 2016年第12期18卷 1220-1224页

作者： Doo-hee CHANG Seung Ho JEONG min PARK Tae-Seong KIm Bong-Ki JUNG kwang Won LEE Sang Ryul IN Division of Nuclear Fusion Engineering & Technology Development Korea Atomic Energy Research Institute

A large-area high-power radio-frequency（RF） driven ion source was developed for positive and negative neutral beam injectors at the Korea Atomic Energy Research Institute（KAERI）. The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 mHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of high-power RF discharge. Plasma ignition of the ion source is initiated by the injection of argongas without a starter-filament heating, and the argon-gas is then slowly exchanged by the injection of hydrogen-gas to produce pure hydrogen plasmas. The uniformities of the plasma parameter,such as a plasma density and an electron temperature, are measured at the lowest area of the driver region using two RF-compensated electrostatic probes along the direction of the shortand long-dimensions of the driver region. The plasma parameters will be compared with those obtained at the lowest area of the expansion bucket to analyze the plasma expansion properties from the driver region to the expansion region.

关键词： neutral beam injector RF ion source plasma ignition power loading plasma parameters

Ultrasonic Approach of Rayleigh Pitch-Catch Contact Ultrasound Waves on CFRP Laminated Composites

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Journal of materials Science & Technology 2008年第3期24卷 407-409页

作者： In-Young Yang kwang-hee Im Uk Heo David K Hsu Je-Woong Park Hak-Joon Kim Sung-Jin Song School of mechanical Eng. Chosun Univ Department of Automotive Eng. Woosuk Univers-ity Center for Nondestructive Evaluation Iowa State University Dept.of Naval Arch.and Ocean Eng. Chosun Univ School of mechanical Eng. Sungkyunkwan University

CFRP （carbon fiber reinforced plastics） composite materials have wide applicability because of their inherent design flexibility and improved material properties. However, impacted composite structures have 50%-75% less strength than undamaged structures. In this work, a CFRP composite material was nondestructively characterized in order to ensure product quality and structural integrity of CFRP and one-sided pitch-catch technique was developed to measure impacted-damaged area by using an automated-data acquisition system in an immersion tank. A pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave under defect conditions in the composite.

关键词： Impact damages C-scanner Carbon fiber reinforced plastics (CFRP) Pitchcatch mode

Deep Volatiles as the Key for Energy and Environments of the Four-Dimensional Earth System

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Engineering 2019年第3期5卷 393-394页

作者： Ho-kwang mao Craig m. Schiffries Center for High Pressure Science and Technology Advanced Research (HPSTAR) Shanghai 201203 China Geophysical Laboratory Carnegie Institution for Science Washington DC 20015 USA

Carbon, hydrogen, oxygen, nitrogen, sulfur, and their compounds are volatile com.onents that dominate the thin and fragile atmosphere, hydrosphere, and biosphere on Earth’s habitable surface. However, the vast majority of these volatiles are hidden in the deep interior, where the high pressure–temperature conditions drastically and categorically alter the physics and chemistry of the volatiles. Like the bloodstream of an organism, the circulations and interactions of volatiles in the deep Earth modulate climate, resources, energy, natural hazards, and other factors that define the Earth as a unique living and changing planet.

关键词： Four-Dimensional Earth System Deep Volatiles