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Nano Research 2016年第3期9卷 633-643页

作者： Sangbaek Park Hyun-woo Shim Chan woo lee Hee Jo Song Jae-Chan Kim Dong-Wan Kim Department of Materials Science and Engineering Seoul National University Seoul 151-744 Republic of Korea School of Civil Environmental and Architectural Engineering Korea University Seou1136-713 Republic of Korea

We report the facile, one-pot synthesis of 3-D urchin-like W18O49 nanostructures （U-WO） via a simple solvothermal approach. An excellent supercapacitive performance was achieved by the U-WO because of its large Brunauer-Emmett- Teller （BET） specific surface area （ca. 123 m2.g-1） and unique morphological and structural features. The U-WO electrodes not only exhibit a high rate-capability with a specific capacitance （Csp） of -235 F·g-1 at a current density of 20 A.g-1, but also superior long-life performance for 1,000 cycles, and even up to 7,000 cycles, showing -176 F·g-1 at a high current density of 40 A.g-1.

关键词： hierarchical structure W18O49 high-power long cycle life supercapacitor

Intermediate-scale Analysis of Landscape Characteristics Affecting Edge Formation in Burned Forests in Samcheok,Korea

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Journal of Mountain Science 2014年第2期11卷 384-397页

作者： Sang-woo lee Myoung-Soo WON Joo-Mee lee Hai-Gyoung KIM Department of Design Konkuk University Kwangjin-Gu Hwayang-DongSeoul 143-701 South Korea Division of Forest Disaster and Fire prevention Korea Forest Research Institute Graduate Program Department of Landscape Architecture & Urban Planning Texas A&M University College Station Yirakjae Landscape Studio Songdong-Gu Hongik-Dong 210Seoul 133-880 South Korea

Compared to burn interiors, edges exhibit distinct biotic and abiotic conditions that include microclimate, wind speed, sunlight levels, soil composition, moisture content, nutrient availability, population density, and species diversity. This study characterized the landscapes in which burned forest edges formed in Samcheok, Korea. Over the study area, 500-m2 grid cells were generated to capture landscape characteristics. Grid cells intersecting burn boundary lines were designated as edge, while cells without these lines were classified as the interior of burned areas. Topographic variables including slope, elevation, topographic wetness index, solar radiation index, and proportions of fuel and land use types within grid cells were computed in a geographical information system(GIS). Correlation analysis with modified t-test and regression tree analysis were performed to explore the influences of landscape variables on edge formation with avoiding spatial autocorrelation problems. The results indicated that edges formed at low elevations with mild slopes, high topographic wetness, and low solar radiation. Edges were unlikely to form in areas dominated by Japanese red pines at low elevations. Moreover, heterogeneous land use/cover types contributed significantly to edge formation. Different forest management strategies for different landscape conditions can be more effective for enhancing resilience of forests to fire. Reducing susceptible fuel types might be effective at low elevations, while enhancing forest heterogeneity might be more effective at high elevations.

关键词： Forest fire Modified t-test, Edge formation Fuel type Topographic characteristics

Hot electron generation on metal catalysts under surface reaction:Principles, devices, and application

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Chinese Chemical Letters 2018年第6期29卷 727-733页

作者： Ievgen I.Nedrygailov Hyosun lee Si woo lee Jeong Young Park Center for Nanomaterials and Chemical Reactions Institute for Basic Science Graduate School of EEWS Korea Advanced Institute of Science and Technology(KAIST)

Understanding the fundamental mechanisms for charge transfer in supported catalysts is of great importance for heterogeneous catalysis. Several experimental and theoretical results suggest that charge flow through metal-support interfaces leads to the catalytic enhancement that is often observed in mixed catalysts. Therefore, it is crucial to directly probe this charge flow in metal-support catalysts during catalytic reactions. In this review, we consider the main aspects of research studying the processes that create and allow interfacial transfer of highly excited（hot） charge carriers in supported catalysts, and discuss the effect of this charge transfer on catalytic activity. We show a close connection between the phenomena of hot electron creation and chemical energy dissipation that accompanies catalytic reactions at both the gas/solid and liquid/solid interfaces. The intensity of hot electron flow is well correlated with the turnover rates of corresponding reactions, which opens up the possibility for developing new operando methodologies for studying chemical processes on catalytic surfaces.

关键词： Hot electron Energy dissipation Heterogeneous catalysis Metal-support interactions Nanodiode

Beach stabilization by the laying of a drainage layer

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Science China(Technological Sciences) 2012年第9期55卷 2625-2639页

作者： HUR Dong-Soo lee woo-Dong CHO Won-Chul Department of Ocean Civil Engineering(Institute of Marine Industry) Gyeongsang National University445 Inpyeong-dongTongyeong 650-160Korea Department of Ocean Civil Engineering Gyeongsang National University445 Inpyeong-dongTongyeong 650-160Korea Department of Civil and Environmental Engineering Chung-Ang University221 Heuksuk-dong Dongjak-guSeoul 156-756Korea

In the present study, the stabilization effects of the laying of a drainage layer in a sandy beach were analyzed. The numerical model developed by Hur et al. （2011） was used to examine the characteristics of wave-sandy beach interaction with/without a drainage layer. This numericai model directly simulates Wave-Structure-Seabed/Sandy （WASS） beach interaction by consid- ering flow through a porous medium with inertia, laminar and turbulent resistances, and determines the eddy viscosity with the Large Eddy Simulation （LES） turbulent model in a 3-D wave field （LES-WASS-3D）. Based on the numerical results, it ap- pears that the installation of a drainage layer in the beach results in a decrease in both the mean groundwater level around the foreshore and the flow moving offshore on the beach surface. Spatial distributions of the mean groundwater level and wave setup around the foreshore with various arrangements of the drainage layer and conditions of the incident wave are also discussed in this paper.

关键词： drainage layer groundwater level foreshore LES-WASS-3D (3-D numerical simulation) beach stabilization swash zone

The photodynamic therapy on Streptococcus mutans biofilms using erythrosine and dental halogen curing unit

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International Journal of Oral Science 2012年第4期4卷 196-201页

作者： Young-Ho lee Ho-Won Park Ju-Hyun lee Hyun-woo Seo Si-Young lee Department of Pediatric Dentistry Graduate SchoolCollege of DentistryGangneung-Wonju National University Department of Pediatric Dentistry College of DentistryGangneung-Wonju National University Department of Microbiology and Immunology College of DentistryGangneung-Wonju National University

The purpose of our study was to evaluate the effect of photodynamic therapy （PDT）, using erythrosine as a photosensitizing agent and a dental halogen curing unit as a light source, on Streptococcus mutans in a biofilm phase. The S. mutans biofilms were formed in a 24-well cell culture cluster. Test groups consisted of biofilms divided into four groups： group 1： no photosensitizer or light irradiation treatment （control group）; group 2： photosensitizer treatment alone; group 3： light irradiation alone; group 4： photosensitizer treatment and light irradiation. After treatments, the numbers of colony-forming unit （CFU） were counted and samples were examined by confocal laser scanning fluorescence microscopy （CLSM）. Only group 4 （combined treatment） resulted in significant increases in cell death, with rates of 75% and 55% after 8 h of incubation, and 74% and 42% at 12 h, for biofilms formed in brain-heart infusion （BHI） broth supplemented with 0% or O. 1% sucrose, respectively. Therefore, PDT of S. mutans biofilms using a combination of erythrosine and a dental halogen curing unit, both widely used in dental clinics, resulted in a significant increase in cell death. The PDT effects are decreased in biofilms that form in the presence of sucrose.

关键词： biofilms dental halogen curing unit erythrosine photodynamic therapy Streptococcus mutans

Observation and Numerical Simulations with Radar and Surface Data Assimilation for Heavy Rainfall over Central Korea

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Advances in Atmospheric Sciences 2011年第3期28卷 573-590页

作者： Ji-Hyun HA Hyung-woo KIM Dong-Kyou lee Atmospheric Sciences Program School of Earth and Environmental SciencesSeoul National UniversitySeoul 151-747Korea

This study investigated the impact of multiple-Doppler radar data and surface data assimilation on forecasts of heavy rainfall over the central Korean Peninsula;the Weather Research and Forecasting(WRF) model and its three-dimensional variational data assimilation system(3DVAR) were used for this purpose. During data assimilation,the WRF 3DVAR cycling mode with incremental analysis updates(IAU) was used. A maximum rainfall of 335.0 mm occurred during a 12-h period from 2100 UTC 11 July 2006 to 0900 UTC 12 July *** radar data showed that the heavy rainfall was due to the back-building formation of mesoscale convective systems(MCSs).New convective cells were continuously formed in the upstream region,which was characterized by a strong southwesterly low-level jet(LLJ).The LLJ also facilitated strong convergence due to horizontal wind shear,which resulted in maintenance of the *** assimilation of both multiple-Doppler radar and surface data improved the accuracy of precipitation forecasts and had a more positive impact on quantitative forecasting(QPF) than the assimilation of either radar data or surface data *** back-building characteristic was successfully forecasted when the multiple-Doppler radar data and surface data were *** data assimilation experiments,the radar data helped forecast the development of convective storms responsible for heavy rainfall,and the surface data contributed to the occurrence of intensified low-level *** surface data played a significant role in enhancing the thermal gradient and modulating the planetary boundary layer of the model,which resulted in favorable conditions for convection.

关键词： radar and surface data data assimilation mesoscale convective system heavy rainfall

Molecular Mechanism of the Specificity of Protein Import into Chloroplasts and Mitochondria in Plant Cells

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Molecular Plant 2019年第7期12卷 951-966页

作者： Dong wook lee Sumin lee Junho lee Seungjin woo Md.Abdur Razzak Alessandro Vitale Inhwan Hwang Division of Integrative Biosciences and Biotechnology Pohang University of Science and Technology Pohang 37673 Korea Department of Life Sciences Pohang University of Science and Technology Pohang 37673 Korea Istituto di Biologia e Biotecnologia Agraria Consiglio Nazionale Delle Ricerche Milano Italy

Plants possess both types of endosymbiotic organelles, chloroplasts and mitochondria. Transit peptides and presequences function as signal sequences for specific import into chloroplasts and mitochondria, respectively. However, how these highly similar signal sequences confer the protein import specificity remains elusive. Here, we show that mitochondrial- or chloroplast-specific import involves two distinct steps, specificity determination and translocation across envelopes, which are mediated by the N-terminal regions and functionally interchangeable C-terminal regions, respectively, of transit peptides and presequences. A domain harboring multiple-arginine and hydrophobic sequence motifs in the N-terminal regions of presequences was identified as the mitochondrial specificity factor. The presence of this domain and the absence of arginine residues in the N-terminal regions of otherwise common targeting signals confers specificity of protein import into mitochondria and chloroplasts, respectively. AtToc159, a chloroplast import receptor, also contributes to determining chloroplast import specificity. We propose that common ancestral sequences were functionalized into mitochondrial- and chloroplast-specific signal sequences by the presence and absence, respectively, of multiple-arginine and hydrophobic sequence motifs in the N-terminal region.

关键词： transit peptide presequence protein import into chloroplasts and mitochondria N-terminal specificity domain C-terminal common translocation domain import specificity determination

CaCO_3 film synthesis from ladle furnace slag: morphological change, new material properties, and Ca extraction efficiency

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1447-1456页

作者： Seung-woo lee Yong-Jae Kim Jun-Hwan Bang Soochun Chae Center for carbon mineralization Korea Institute of Geosciences and Mineral Resources Frontier in extreme physics Korea Research Institute of Standards and Science

A rapidly air-cooled ladle furnace slag(RA-LFS), which is a type of steelmaking slag discharged from a steel mill, was used to synthesize CaCO_3 film. The CaCO_3 film with 35 cm^2 of surface area was synthesized under atmospheric conditions, and the surface morphology of the CaCO_3 films was changed by using additives(CaCl_2 and ethylene glycol). Especially, the addition of CaCl_2 changed the surface morphology of CaCO_3 film with pore and induced new material properties, such as water adsorption. The(012) face of CaCO_3 film(calcite) was rapidly decreased by the addition of CaCl_2. The major components of RA-LFS were calcium(type of CaO, 53.9 wt%) and aluminum(type of Al_2 O_3, 37.9 wt%), and the major crystal phases of RA-LFS were C_3 S, C_(12) A_7, and C_3 A. The calcium extraction efficiency of RA-LFS was significantly increased after the CaCO_3 film synthesis. The material properties(hardness and elastic modulus) and the thermal characteristics of the CaCO_3 films were analyzed by nano-indentation and thermogravimetry–differential thermal analysis. The synthesized CaCO_3 films from RA-LFS and Ca(OH)_2(reagent) showed similarities in terms of their material properties and the decomposition temperature.

关键词： carbon dioxide ladle furnace slag carbonation calcium carbonate film calcium efficiency

Spontaneous rupture of adrenal myelolipoma as a cause of acute flank pain:A case report

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World Journal of Clinical Cases 2021年第22期9卷 6552-6556页

作者： Dong Soo Kim Jeong woo lee Sang Hyub lee Department of Urology School of MedicineKyung Hee UniversitySeoul 02447South Korea

BACKGROUND Adrenal myelolipoma is a rare,benign,non-functioning mass that occurs in the adrenal *** is composed of an admixture of hematopoietic elements and mature adipose tissue,similar to bone *** at large sizes,adrenal myelolipomas are usually asymptomatic and often incidentally found by ultrasonography or computed tomography(CT)*** paper describes an unusual case of adrenal myelolipoma presenting as flank *** SUMMARY A 50-year-old male with severe right flank pain underwent a CT scan revealing a huge mass extending into the suprarenal *** mass showed a fat component with retroperitoneal *** tumor was treated laparoscopically,and pathologic examination revealed features of myelolipoma originating from the adrenal *** Adrenal myelolipomas are generally asymptomatic and can be treated ***,rupture and hemorrhage of the tumor can cause symptoms requiring surgical removal.

关键词： Adrenal neoplasms Myelolipoma Adrenal glands Case report

High efficiency and stable solid-state fiber dye-sensitized solar cells obtained using TiO_(2) photoanodes enhanced with metal organic frameworks

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Journal of Energy Chemistry 2022年第4期31卷 458-466页

作者： Jae Ho Kim Hyun woo Park Sung-Jun Koo Daseul lee Eunyeong Cho Yong-Ki Kim Myunghun Shin Jin woo Choi Hee Jung lee Myungkwan Song Department of Energy and Electronic Material Korea Institute of Materials Science(KIMS)797 Changwon-daeroSungsan-guChangwonGyeongsangnam-do 51508Republic of Korea Composites Research Division Korea Institute of Materials Science(KIMS)797 Changwon-daeroSungsan-GuChangwonGyeongsangnam-do 51508Republic of Korea School of Electronics and Information Engineering Korea Aerospace UniversityGoyang-cityGyeonggi-do 10540Republic of Korea

Solid-state fiber dye-sensitized solar cells(SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal–organic frameworks(MOFs) are one such material that has been utilized to further improve the power conversion efficiency of solar cells. In this study, MOF-integrated DSSCs were shown to have potential in the development of solar cell devices with efficiency comparable to or better than that of conventional solar cells. The power conversion efficiency(PCE) of SS-FDSSCs was improved by embedding MOF-801 into a mesoporous-TiO_(2)(mp-TiO_(2)) layer, which was used as a photoanode in SS-FDSSCs, which are inherently flexible. The PCE of the MOF-integrated SS-FDSSCs was 6.50%, which is comparable to that of the reference devices(4.19%).The MOF-801 enhanced SS-FDSSCs decreased the series resistance(R_(s)) value, resulting in effective electron extraction with improved short-circuit current density(J_(SC)), while also increasing the shunt resistance(R_(sh)) value to prevent the recombination of photo-induced electrons. The result is an improved fill factor and, consequently, a higher value for the PCE.

关键词： Photoanode Metal organic frameworks Solid-state electrolyte Dye-sensitized solar cells Fiber-shaped solar cells