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Short Communication—A Novel Sample Preparation Method That Enables Ultrathin Sectioning of Urea-Formaldehyde Resin for Imaging by Transmission Electron Microscopy

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Microscopy Research 2013年第1期1卷 1-6页

作者： Adya P. Singh Arif Nuryawan byung- dae park Department of Wood Science and Technology Kyungpook National University Daegu South Korea.

Urea-formaldehyde (UF) resin is widely used as an adhesive for the manufacture of a range of wood and fiber based products. Although the microstructure of this resin has been examined at high resolution by field-emission scanning electron microscopy and atomic force microscopy, transmission electron microscopy (TEM) has thus far not been used, perhaps because of difficulties in ultrathin sectioning this resin in cured (polymerized) state. In the technical note presented here, a novel sample preparation method is described which enabled us to examine the microstructural morphology of UF resin by transmission electron microscopy in ultrathin sections, revealing the presence of spherical particles within the resin. Our initial attempt to ultrathin section the resin directly was not successful as it was too brittle to trim blocks for sectioning. Then, we developed a sample preparation technique that involved impregnation ofPinus radiatawood tissues with the UF resin, and then embedding of resin impregnated wood tissues with Spurr’s low viscosity embedding medium, which has been widely employed in plant and wood ultrastructure work. The TEM images illustrated and the information on the microstructural morphology of the UF resin presented are based on this novel sample preparation approach.

关键词： Urea-Formaldehyde (UF) Resin Ultrathin Sectioning Transmission Electron Microscopy Pinus radiata Veneer Microstructure Spherical Particles

Advances in Probing Wood-Coating Interface by Microscopy: A Review

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Journal of Surface Engineered Materials and Advanced Technology 2013年第1期3卷 49-54页

作者： Adya P. Singh byung-dae park Arif Nuryawan Menda Kazayawoko Departement de Gestion des Ressources Naturelles Faculte des Sciences Agronomiques Universite de Kinshasa Kinshasa Democratic Republic of the Congo Department of Wood Science and Technology Kyungpook National University Daegu South Korea

Surface coatings provide protection to wood products against weathering and other deteriorating factors, such as moisture uptake and microbial invasion. The effectiveness of coatings depends on many factors, including how well the applied coatings adhere to the wood surface. Coating adhesion to wood involves both chemical and physical interactions between the coating and wood tissues in contact, and the particular focus of this mini-review will be on the advances being made in understanding the physical aspects of the interaction by probing wood-coating interface using novel and high resolution imaging techniques, including confocal laser scanning microscopy (CLSM), SEM-backscattered electron imaging and correlative microscopy employing light, confocal and scanning electron microscopy.

关键词： Wood-Coating Interface Coating Adhesion Correlative Microscopy Backscattered Electron Imaging Confocal Laser Scanning Microscopy

N,P co-doped 3D porous carbon with self-assembled morphological control via template-free method for potassiumion battery anodes

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Rare Metals 2024年第9期43卷 4243-4252页

作者： Jeehoon Yu dae Kyom Kim Hong Geun Oh Seung-Keun park Youngjae Yoo Department of Advanced Materials Engineering Chung-Ang UniversityAnseong-si 17546Republic of Korea

The larger ionic radius of potassium ions than that of lithium ions significantly limits the accomplishment of rapid diffusion kinetics in graphite electrodes for potassium-ion batteries(PIBs),resulting in comparatively poor rate performance and cycle ***,we report a high-rate performance and cycling stability amorphous carbon electrode achieved through nitrogen and phosphorous *** as-prepared N,P co-doped carbon electrodes have distinct 3D structures with large surface areas,hierarchical pore architectures,and increased interlayer spaces resulting from the direct pyrolysis of supramolecular self-assembled aggregates without *** obtained electrode N3P1 exhibits a reversible specific capacity of 258 m Ah·g^(-1)at a current density of 0.1A·g^(-1)and a good long-term cycle performance(96.1%capacity retention after 800 cycles at 0.5 A·g^(-1)).Kinetic investigations show that the N3P1 electrode with the welldeveloped porous structure and large number of surface defects exhibits capacitive-driven behavior at all scan rates,which may be attributed by N and P ***-situ transmission electron microscopy analyses in the fully discharged and charged states demonstrate structural stability and reversibility owing to the expanded interlayer *** suggested synthesis approach is simple and effective for producing heteroatom-doped carbon materials for PIBs and other advanced electrochemical energy storage materials.

关键词： Amorphous carbons 3D porous structures Nitrogen and phosphorous co-doping Potassium-ion batteries

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Fabrication of heteroatom-doped cobalt oxide yolk–shell microsphere using recycled solution from waste materials and their excellent electrochemical properties as an anode material for lithium-ion batteries

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Rare Metals 2024年第10期43卷 4934-4947页

作者： Yeong Beom Kim Chanho Kim Seung-Hyun Kim Yun Chan Kang Dongju Lee Gi dae park Department of Advanced Materials Engineering Chungbuk National University Department of Materials Science and Engineering Korea University Research Institute YKSintering Co.Ltd.

Heteroatom-doped transition metal oxides have attracted great attention as advanced anode materials for lithium-ion batteries due to their high theoretical capacity and superior ***,the limited resource availability has led to a substantial rise in prices for valuable metals such as Ni and Co,posing a significant challenge for their *** address this issue,recycling of these metals from waste materials have gained prominence,and particularly the recovery of Co has been mostly focused on its economic ***,we introduced a novel recycling strategy for fabrication of heteroatomdoped CoOx（comprising mainly Co3O4with a minor CoO phase） anode with a yolk–shell structure for lithium-ion batteries,by separating Co from cemented tungsten carbide *** employing a simple leaching process and subsequent spray pyrolysis,the yolk–shell structured microsphere comprising CoOxwas successfully ***,the presence of other waste metals in the leachate facilitated multi-heteroatom doping during ***,the introduction of various dopants into CoOxinduced oxygen vacancy formation,thereby enhancing the electrochemical properties of the *** a result,compared with the phase-pure （undoped） CoOxyolk–shell,the heteroatom-doped CoOxyolk–shell exhibited robust cycling stability (602 mAh·g-1for 200 cycles at 1 A·g-1) and excellent rate capability(210 mAh·g-1at 10 A·g-1).

关键词： Anode Cobalt oxide Heteroatom doping Lithium-ion batteries Recycling

Insect-based agri-food waste valorization:Agricultural applications and roles of insect gut microbiota

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Environmental Science and Ecotechnology 2024年第1期17卷 4-16页

作者： Mohamed Mannaa Abdelaziz Mansour Inmyoung park dae-Weon Lee Young-Su Seo Department of Integrated Biological Science Pusan National UniversityBusan46241Republic of Korea Department of Plant Pathology Cairo UniversityFaculty of AgricultureGiza12613Egypt Department of Economic Entomology and Pesticides Faculty of AgricultureCairo UniversityGiza12613Egypt School of Food and Culinary Arts Youngsan UniversityBansong BeltwayBusan48015Republic of Korea Department of SmartBio Kyungsung UniversityBusan48434Republic of Korea

Meeting the demands of the growing population requires increased food and feed production,leading to higher levels of agri-food *** this type of waste seriously threatens public health and the environment,novel approaches to waste management should be *** have been proposed as efficient agents for biorefining waste,producing biomass that can be used for commercial ***,challenges in achieving optimal outcomes and maximizing beneficial results *** symbionts associated with insects are known to have a critical role in the development,fitness,and versatility of insects,and as such,they can be utilized as targets for the optimization of agri-food waste insect-based biorefinery *** review discusses insect-based biorefineries,focusing on the agricultural applications of edible insects,mainly as animal feed and organic *** also describe the interplay between agri-food waste-utilizing insects and associated microbiota and the microbial contribution in enhancing insect growth,development,and involvement in organic waste bioconversion *** potential contribution of insect gut microbiota in eliminating pathogens,toxins,and pollutants and microbe-mediated approaches for enhancing insect growth and the bioconversion of organic waste are also *** present review outlines the benefits of using insects in agri-food and organic waste biorefinery systems,describes the roles of insect-associated microbial symbionts in waste bioconversion processes,and highlights the potential of such biorefinery systems in addressing the current agri-food waste-related challenges.

关键词： Edible insects Bioconversion Animal feed Frass fertilizer Symbiotic bacteria

Vertical plane depth-resolved surface potential and carrier separation characteristics in flexible CZTSSe solar cells with over 12% efficiency

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Carbon Energy 2024年第3期6卷 36-52页

作者： dae-Ho Son Ha Kyung park dae-Hwan Kim Jin-Kyu Kang Shi-Joon Sung dae-Kue Hwang Jaebaek Lee Dong-Hwan Jeon Yunae Cho William Jo Taeseon Lee JunHo Kim Sang-Hoon Nam Kee-Jeong Yang Division of Energy Technology DGISTDaeguRepublic of Korea Research Center for Thin Film Solar Cells DGISTDaeguRepublic of Korea Department of Physics Ewha Womans UniversitySeoulRepublic of Korea Department of Physics Incheon National UniversityIncheonRepublic of Korea Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMassachusettsUSA

Cu2ZnSn(S,Se)4(CZTSSe)solar cells have resource distribution and economic *** main cause of their low efficiency is carrier loss resulting from recombination of photo-generated electron and *** overcome this,it is important to understand their electron-hole behavior *** determine the carrier separation characteristics,we measured the surface potential and the local current in terms of the absorber *** elemental variation in the intragrains(IGs)and at the grain boundaries(GBs)caused a band edge shift and bandgap(Eg)*** the absorber surface and subsurface,an upward Ec and Ev band bending structure was observed at the GBs,and the carrier separation was *** the absorber center,both upward Ec and Ev and downward Ec-upward Ev band bending structures were observed at the GBs,and the carrier separation was *** improve the carrier separation and suppress carrier recombination,an upward Ec and Ev band bending structure at the GBs is desirable.

关键词： carrier separation CZTSSe flexible solar cell local current surface potential

Trifunctional robust electrocatalysts based on 3D Fe/N-doped carbon nanocubes encapsulating Co4N nanoparticles for efficient battery-powered water electrolyzers

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Carbon Energy 2024年第6期6卷 124-139页

作者： Hyung Wook Choi Hongdae Lee Jun Lu Seok Bin Kwon Dong In Jeong Beum Jin park Jiwon Kim Bong Kyun Kang Gun Jang dae Ho Yoon Ho Seok park SKKU Advanced Institute of Nano Technology(SAINT) Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea School of Chemical Engineering Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea Department of Electronic Materials Devicesand Equipment EngineeringSoonchunhyang UniversityAsan CityChungnamRepublic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea Department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences and Technology(SAIHST)Sungkyunkwan UniversitySuwonRepublic of Korea

Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize hierarchically structured Co_(4)N@Fe/N-C for rechargeable zinc-air batteries and overall water-splitting *** confirmed by theoretical and experimental results,the high intrinsic oxygen reduction reaction,oxygen evolution reaction,and hydrogen evolution reaction activities of Co_(4)N@Fe/N-C were attributed to the formation of the heterointerface and the modulated local electronic ***,Co_(4)N@Fe/N-C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure,uniform distribution of Co_(4)N,and conductive encapsulation by Fe/***,the rechargeable zinc-air battery with Co_(4)N@Fe/N-C delivers a high specific capacity of 789.9 mAh g^(-1) and stable voltage profiles over 500 ***,the overall water electrolyzer with Co_(4)N@Fe/N-C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts,delivering a high Faradaic efficiency of 96.4%.Along with the great potential of the integrated water electrolyzer powered by a zinc-air battery for practical applications,therefore,the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.

关键词： battery-powered electrolyzers hierarchical structure Prussian blue analog trifunctional electrocatalyst zinc-air battery

Functionally graded structure of a nitride-strengthened Mg_(2)Si-based hybrid composite

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Journal of Magnesium and Alloys 2024年第3期12卷 1239-1256页

作者： Jeongho Yang Woongbeom Heogh Hogi Ju Sukhyun Kang Tae-Sik Jang Hyun-Do Jung Mohammad Jahazi Seung Chul Han Seong Je park Hyoung Seop Kim Susmita Bose Amit Bandyopadhyay Martin byung-Guk Jun Young Won Kim dae-kyeom Kim Rigoberto CAdvincula Clodualdo Aranas Jr Sang Hoon Kim School of Mechanical Engineering Pusan National UniversityBusan 46241Republic of Korea Department of Mechanical Design Engineering Hanyang UniversitySeoul 04763Republic of Korea Process Research 3 Team LG Display Co.Ltd.PajuGyeonggi-do 10845Republic of Korea Department of Materials Science and Engineering Chosun UniversityGwangju 61452Republic of Korea Institute of Well-Aging Medicare&Chosun University LAMP Center Chosun UniversityGwangju 61452Republic of Korea Division of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Department of Mechanical Engineering École de Technologie SupérieureMontrealQuebec H3C 1K3Canada Material&Component Convergence R&D Center Korea Construction Equipment Technology InstituteGunsanJeollabuk-do 54002Republic of Korea School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore Graduate Institute of Ferrous&Eco Materials Technology Pohang University of Science and TechnologyPohangGyeongsangbuk-do 37673Republic of Korea Advanced Institute for Materials Research Tohoku UniversitySendai 980-8577Japan Institute for Convergence Research and Education in Advanced Technology Yonsei UniversitySeoul 03722Republic of Korea School of Mechanical and Materials Engineering Washington State UniversityPullmanWashington 99164USA School of Mechanical Engineering Purdue UniversityWest LafayetteIndiana 47907USA Research Institute of Advanced Manufacturing Technology Korea Institute of Industrial TechnologyIncheon 21999Republic of Korea Department of Macromolecular Science and Engineering Case Western Reserve UniversityClevelandOhio 44106USA Department of Chemical and Biomolecular Engineering and Joint Institute for Advanced Materials University of TennesseeKnoxvilleTennessee 37996USA Center for Nanophase Materials and Sciences Oak Ridge National LaboratoryOak RidgeTennessee 37830USA Department of Mechanical Engineering University of New BrunswickFrederictonNew Brunswick E3B 5A3Cana

The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in order to provide ultimate wear resistance based on the laser-irradiation-induced inclusion of N_(2) gas during laser powder bed *** is substantialized based on both the thermal diffusion-and chemical reactionbased metallurgy of the Mg_(2)Si–SiC/nitride hybrid *** study also proposes a functional platform for systematically modulating a functionally graded structure and modeling build-direction-dependent architectonics during additive *** strategy enables the development of a compositional gradient from the center to the edge of each melt pool of the Mg_(2)Si–SiC/nitride hybrid ***,the coefficient of friction of the hybrid composite exhibits a 309.3%decrease to–1.67 compared to–0.54 for the conventional nonreinforced Mg_(2)Si structure,while the tensile strength exhibits a 171.3%increase to 831.5 MPa compared to 485.3 MPa for the conventional *** outstanding mechanical behavior is due to the(1)the complementary and synergistic reinforcement effects of the SiC and nitride compounds,each of which possesses an intrinsically high hardness,and(2)the strong adhesion of these compounds to the Mg_(2)Si matrix despite their small sizes and low concentrations.

关键词： Laser powder bed fusion Mg_(2)Si-SiC/nitride hybrid composite Both the thermal diffusion-and chemical reaction-based metallurgy Functionally graded structure Compositional gradient Wear resistance.

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Acupuncture ameliorates atopic dermatitis by modulating gut barrier function in a gut microbiota-dependent manner in mice

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Journal of Integrative Medicine 2024年第5期22卷 600-613页

作者： Mijung Yeom Sora Ahn dae-Hyun Hahm Sun-Young Jang Se Hoon Jang Su-Yang park Jae-Hwan Jang Jihan park Ju-Young Oh In-Seon Lee Kyuseok Kim Soon-Kyeong Kwon Hi-Joon park Acupuncture and Meridian Science Research Center College of Korean MedicineKyung Hee UniversitySeoul 02447Republic of Korea Department of Physiology School of MedicineKyung Hee UniversitySeoul 02447Republic of Korea BioNanocomposite Research Center Kyung Hee UniversitySeoul 02447Republic of Korea Department of Science in Korean Medicine College of Korean MedicineGraduate SchoolKyung Hee UniversitySeoul 02447Republic of Korea College of Korean Medicine Kyung Hee UniversitySeoul 02447Republic of Korea Department of Ophthalmology Otorhinolaryngology and Dermatology of Korean MedicineCollege of Korean MedicineKyung Hee UniversitySeoul 02447Republic of Korea Division of Applied Life Science(BK21) Gyeongsang National UniversityJinju 52828Republic of Korea Department of Anatomy&Information Sciences College of Korean MedicineKyung Hee UniversitySeoul 02447Republic of Korea

Objective Atopic dermatitis(AD)is a chronic inflammatory skin disease that may be linked to changes in the gut *** has been proven to be effective in reducing AD symptoms without serious adverse events,but its underlying mechanism is not completely *** purpose of this study was to investigate whether the potential effect of acupuncture on AD is gut *** AD-like skin lesions were induced by applying MC903 topically to the cheek of the *** was done at the Gok-Ji(LI11)***-like symptoms were assessed by lesion scores,scratching behavior,and histopathological changes;intestinal barrier function was measured by fecal output,serum lipopolysaccharide levels,histopathological changes,and mRNA expression of markers involved in intestinal permeability and *** microbiota was profiled using 16S rRNA gene sequencing from fecal *** Acupuncture effectively improved chronic itch as well as the AD-like skin lesions with epidermal thickening,and also significantly altered gut microbiota structure as revealed byβ-diversity indices and analysis of *** beneficial effects were eliminated by antibiotic depletion of gut microbiota,but were reproduced in gut microbiota-depleted mice that received a fecal microbiota transplant from acupuncture-treated ***,AD mice had intestinal barrier dysfunction as indicated by increased intestinal permeability,atrophy of the mucosal structure(reduced villus height and crypt depth),decreased expression of tight junctions and mucus synthesis genes,and increased expression of inflammatory mediators in the *** attenuated these abnormalities,which was gut *** Acupuncture ameliorates AD-like phenotypes in a gut microbiota-dependent manner and some of these positive benefits are explained by modulation of the intestinal barrier,providing new perspective for non-pharmacological strategies for

关键词： Atopic dermatitis Acupuncture Gut microbiota Intestinal barrier function

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