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Portable nano probe for micro/nano mechanical scratching and measuring

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Transactions of Nonferrous Metals Society of China 2011年第A01期21卷 205-209页

作者： Woo-Park JEONG Chang-Choi soo Cho HYUN Woo-lee DEUG Department of Mechanical Design Engineering Chosun University Department of Nano Fusion Technology Pusan National University Department of Nano-mechatronics Engineering Pusan National University

A nano probe system which can measure precise contact force in mN scale was demonstrated. The nano probe micro parts or optical parts in nanometer range resolution and scratch was originally designed for on-machine measuring applications and one kind of contact type measuring probes was designed for miniaturized or microfactory system. It ideally should be of small size and able to measure surface topography in nanometer scale. A commercial capacitive displacement sensor was proposed. It was a new concept in nano probe systems which can measure the displacement of shaft driven by the variation of surface topography. The nano probe mainly consisted of three parts： a capacitive displacement sensor, a porous type air slide and a contact probe part with various tip radiuses. The porous type air slide assured the shaft slided smoothly with controllable normal force in mN scale and had high positioning accuracy. The probe part which was directly in contact with target surface, can be applied to micro/nanoscale scratching as well as the measurement of sample topography by a simple tip change.

关键词： nano probe displacement sensor air slide PCD tip

Chemical composition and antioxidant capacity of the aqueous extract of Phellodendron amurense

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Journal of Forestry Research 2018年第4期29卷 1033-1040页

作者： Natarajan Velmurugan Duraisamy Kalpana Jae Young Cho Yang soo lee Department of Forestry College of Agriculture and Life Sciences Chonbuk National University Jeonju 54896 Republic of Korea Branch Laboratory-Itanagar CSIR-North East Institute of Science and Technology Naharlagun Arunachal Pradesh 791 110 India Department of Agricultural Chemistry Chonbuk National University Jeonju 54896 Republic of Korea

The aqueous extract of Phellodendron amurense Rupr. （Amur Cork Tree） provides a rich source of antioxidants and chemical compounds, and can be used for food and wood preservative materials. In this study, we characterized the chemical composition of this extract by GC and GC/MS. The antioxidant capacity was evaluated using a variety of antioxidant assays （superoxide radical, hydroxyl radical, nitric oxide radical, and DPPH radical scavenging activity）. Additionally, total polyphenolic content was determined. Phenolic acids and acetone derivatives were major compounds of the extract capable of scavenging the DPPH free radical and reducing ferric ions. DPPH and ferric ion reduction results were strongly correlated with total phenolic content of the extract which also exhibited strong nitric oxide, hydroxyl radical scavenging and superoxide anion radical scavenging activities.

关键词： Phellodendron amurense Aqueous extract Chemical characterization Antioxidant activity

Simulation of Storm Surge and Wave Due to Typhoon Isewan(5915)

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China Ocean Engineering 2015年第4期29卷 473-488页

作者： Jin-Hee YUK Kyeong Ok KIM Han soo lee Byung Ho CHOI Disaster Management HPC Technology Research Center Korea Institute of Science and Technology Information Marine Radionuclide Research Center Korea Institute of Ocean Science & Technology Graduate School of Science and Engineering Saitama University Department of Civil and Environmental Engineering Sungkyunkwan University

An integrally coupled wave-tide-surge model was developed and then applied to the simulation of the wave-typhoon surge for the typhoon Isewan （typhoon Vera （5915））, which is the strongest typhoon that has struck Japan and caused incalculable damage. An integrally coupled tide-surge-wave model using identical and homogeneous meshes in an unstructured grid system was used to correctly resolve the physics of wave-circulation interaction in both models. All model components were validated independently. The storm surge and wave properties such as the surge height, the significant wave height, wave period and direction were reproduced reasonably under the meteorological forcing, which was reprocessed to be close to the observations. The resulting modeling system can be used extensively for the prediction of the storm surge and waves and the usual barotropic forecast.

关键词： typhoon Isewan storm surge wave tide coupled wave-tide-surge model

Characteristics of machined surface controlled by cutting tools and conditions in machining of brittle material

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中国有色金属学会会刊：英文版 2009年第B09期19卷 194-201页

作者： Yong-Woo KIM soo-Chang CHOI Jeung-Woo PARK Deug-Woo lee Department of Nano Fusion Technology Pusan National University Department of Mechanical Design Engineering Chosun University Department of Nanosystem and Nanoprocess Engineering Pusan National University

One of the ultra-precision machining methods was adapted for brittle material as well as soft material by using multi-arrayed diamond tips and high speed spindle. Conventional machining method is too hard to control surface roughness and surface texture against brittle material because the particles of grinding tools are irregular size and material can be fragile. Therefore, we were able to design tool paths and machine controlled pattern on surface by multi-arrayed diamond tips with uniform size made in MEMS fabrication and high speed spindle, and the maximum speed was about 3×105 r/min. We defined several parameters that can affect the machining surface. Those were multi-array of diamond tips (n×n), speed of air spindle and feeding rate. The surface roughness and surface texture can be controlled by those parameters for micro machining.

关键词：加工表面脆性材料条件控制刀具路径表面粗糙度特征高速主轴加工方法

Changes and development plans in the mountain villages of South Korea:Comparison of the first and second national surveys

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Journal of Mountain Science 2017年第8期14卷 1473-1489页

作者： Hag Mo KANG Hyun KIM Chang Heon lee Chong Kyu lee soo Im CHOI Department of Forest Environmental Science Chonbuk National University Jeollabuk-do Forest Environment Research Institute Department of Forest Resources Gyeongnam National University of Science and Technology Department of Forest Resources Sunchon National University

Owing to the geographic disadvantages of mountain villages, the social, cultural, and economic conditions of mountain villagers are inferior to those of urban dwellers in South Korea. Thus, in 1995, the The government of South Korea launched a mountain village development support program to promote agriculture and forestry, balance national land development, and preserve cultural heritage. The program was effectively implemented, improving the income, population size, and living conditions of villagers in addition to setting up a system for stable project implementation. However, concerns were raised about long-term development planning, the creation and marketing of specialty brands, facility management/operation, and follow-up support. The government conducted surveys of mountain villagers in 2003 and 2014, obtaining basic data to address these issues. This study evaluates the outcomes of these two surveys, suggesting areas requiring focusedaction, concentrating on village development projects, forest resource distribution and use, demographic trends, the economy, exchange with urban areas, green tourism, and master planning. We find that despite growth in the forest labor force, forest ownership is diminishing in terms of the number and scale of holdings. Consequently, it is necessary to commercialize forest resources, establish favorable settlement conditions, and expand government support for village-run projects. In addition, systematic forest management for older tree age classes would benefit the public and provide assets for future mountain village development. Our results are expected to provide baseline information for the establishment and efficient implementation of mountain village development policy.

关键词： Forest resources management Mountain village changes Mountain village economy Support for mountain villages Urban-rural exchange

Electrodeposited Ni-W-TiC Composite Coatings:Effect of TiC Reinforcement on Microstructural and Tribological Properties

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Acta Metallurgica Sinica(English Letters) 2020年第4期33卷 573-582页

作者： Jin Hyuk Choi Gobinda Gyawali Dhani Ram Dhakal Bhupendra Joshi soo Wohn lee Department of Materials Metal Engineering Sun Moon University31460 AsanSouth Korea Department of Fusion Science and Technology Sun Moon UniversityTangjeong Myeon31460 AsanChungnamSouth Korea Department of Environmental and Bio-Chemical Engineering Sun Moon University31460 AsanSouth Korea

Ni-W-TiC composite coatings were prepared via electrodeposition technique by dispersing the different amount of TiC particles into the plating *** Ni-W and Ni-W-TiC composite coatings containing different concentrations of TiC particles were characterized by using the scanning electron microscope,X-ray diffraction technique,Vickers microhardness test,surface roughness test,and tribology *** results show that the Ni-W coatings containing reinforced TiC particles have shown a typical FCC Ni-W crystal structure with significantly higher Vickers *** amount of dispersed TiC particles into the plating bath considerably affected codeposition weight percent of TiC into the Ni-W matrix,as revealed by the EDS ***-W-TiC samples demonstrated the decreased abrasive wear as compared to Ni-W coating and no characteristic features observed for the adhesive ***,an improvement in coefficient of friction was observed in Ni-W-TiC composite coating as compared to Ni-W coating.

关键词： Ni-W alloy Composite coating Microhardness Wear Coefficient of friction

Perfluorooctanoic acid(PFOA) and perfluorooctanesulfonic acid(PFOS) concentrations in the South Korean agricultural environment: A national survey

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Journal of Integrative Agriculture 2017年第8期16卷 1841-1851页

作者： Geun-Hyoung Choi Deuk-Young lee Dong-Kyu Jeong Saranya Kuppusamy Yong bok lee Byung-Jun Park Jin-Hyo Kim Chemical Safety Division National Institute of Agricultural ScienceRural Development Administration Division of Applied Life Science(BK21 Plus) Institute of Agriculture and Life Science(IALS)Gyeongsang National University

Research on the occurrence of perfluorochemicals （PFCs） such as perfluorooctanesulfonic acid （PFOS） and perfluorooctanoic acid （PFOA） in the agricultural environment is lacking, in spite of their potential risk via food chain transfer from aquatic and soil-plant systems to animals and/or humans. In the present study, for the first time, soil and water samples collected from 243 different agricultural sites adjacent to waste water treatment plants （WWTPs） belonging to 81 cities and 5 provinces with different levels of industrialization in South Korea were monitored for concentrations of PFOS and PFOA by use of solid phase extraction and liquid chromatography-tandem mass spectroscopy （LC-MS/MS）. Significant mean concentrations of PFOA （0.001-0.007 tJg L-1 water and 〈0.05-1.573 tJg kg-1 soil） and PFOS （0.001-0.22 tJg L-1 water and 〈0.05-0.741 pg kg-1 soil） were found in all samples. Concentrations of PFCs in soils were high, highlighting that soil is an important sink for PFCs in the agricultural environment. Samples from near WWTPs in Gyeongsang Province contained the highest concentrations of PFOS and PFOA, reflecting the concentration of heavy industry in the province. The concentrations of PFCs in agricultural water （most samples 〈0.05 pg L-~） and soils （most samples 〈1 IJg kg-~） from South Korea were less than acceptable guideline values, indicating that South Korea is not a hotspot of PFOS and PFOA contamination and that there is negligible risk to human and ecological health from these chemicals. However, further studies investigating the seasonal variation in PFOA, PFOS and other perfluorochemical concentrations in the agricultural environment are needed.

关键词： PFOS PFOA agricultural environment residual concentration South Korea

ASpediaFI:Functional Interaction Analysis of Alternative Splicing Events

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Genomics, Proteomics & Bioinformatics 2022年第3期20卷 466-482页

作者： Kyubin lee Doyeong Yu Daejin Hyung soo Young Cho Charny Park Bioinformatics Branch Research InstituteNational Cancer CenterGoyang 10408Republic of Korea

Alternative splicing(AS)regulates biological processes governing phenotypes and *** AS(DAS)gene test methods have been developed to investigate important exonic expression from high-throughput ***,the DAS events extracted using statistical tests are insufficient to delineate relevant biological *** this study,we developed a novel application,Alternative Splicing Encyclopedia:Functional Interaction(ASpediaFI),to systemically identify DAS events and co-regulated genes and *** establishes a heterogeneous interaction network of genes and their feature nodes(i.e.,AS events and pathways)connected by coexpression or pathway gene set ***,ASpediaFI explores the interaction network using the random walk with restart algorithm and interrogates the proximity from a query gene ***,ASpediaFI extracts significant AS events,genes,and *** evaluate the performance of our method,we simulated RNA sequencing(RNA-seq)datasets to consider various conditions of sequencing depth and sample *** performance was compared with that of other ***,we analyzed three public datasets of cancer patients or cell lines to evaluate how well ASpediaFI detects biologically relevant *** exhibits strong performance in both simulated and public *** integrative approach reveals that DAS events that recognize a global co-expression network and relevant pathways determine the functional importance of spliced genes in the *** is publicly available at https://***/packages/ASpediaFI.

关键词： Alternative splicing RNA-seq Heterogeneous interaction network Random walk with restart Gene set enrichment analysis

Steam activation of Fe-N-C catalyst for advanced power performance of alkaline hydrazine fuel cells

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Journal of Energy Chemistry 2022年第1期31卷 276-285,I0008页

作者： sooan Bae Jihyeon Park Yuna Hwang Jin-soo Park Jaeyoung lee Beomgyun Jeong Research Center for Materials Analysis Korea Basic Science Institute169-14&Gwahak-roDaejeon 34133Republic of Korea School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology123 Cheomdangwagi-ro.Buk-guGwangju 61005Republic of Korea Department of Green Chemical Engineering Sangmyung University31 Sangmyungdae-gilDongnam-gu.CheonanChungnam Province 31066Republic of Korea Ertl Center for Electrochemistry and Catalysis Gwangju Institute of Science and Technology123 Cheomdangwagi-roBuk-giiGwangju 61005Republic of Korea

Alkaline hydrazine liquid fuel cells(AHFC) have been highlighted in terms of high power performance with non-precious metal *** Fe-N-C is a promising non-Pt electrocatalyst for oxygen reduction reaction(ORR),the surface density of the active site is very low and the catalyst layer should be thick to acquire the necessary number of catalytic active *** this thick catalyst layer,it is important to have an optimum pore structure for effective reactant conveyance to active sites and an interface structure for faster charge ***,we prepare a Fe-N-C catalyst with magnetite particles and hierarchical pore structure by steam *** steam activation process significantly improves the power performance of the AHFC as indicated by the lower IR and activation voltage *** on a systematic characterization,we found that hierarchical pore structures improve the catalyst utilization efficiency of the AHFCs,and magnetite nanoparticles act as surface modifiers to reduce the interracial resistance between the electrode and the ion-exchange membrane.

关键词： Alkaline hydrazine fuel cell Oxygen reduction reaction Electrocatalyst Steam activation Ohmic loss Interfacial resistance Surface modifier