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Synthesis and Characterization of Magnetite/Carbon Nanocomposite Thin Films for Electrochemical Applications

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Journal of Materials Science & Technology 2011年第10期27卷 873-878页

作者： Suh Cem Pang Wai Hwa Khoh suk Fun Chin Department of Chemistry Faculty of Resource Science and TechnologyUniversiti Malaysia Sarawak

Stable colloidal suspension of magnetite/starch nanocomposite was prepared by a facile and aqueous-based chemical precipitation method, Magnetite/carbon nanocomposite thin films were subsequently formed upon carbonization of the starch component by heat treatment under controlled conditions. The initial content of native sago starch as the carbon source was found to affect the microstructure and electrochemical properties of the resulted magnetite/carbon nanocomposite thin films, A specific capacitance of 124 F/g was achieved for the magnetite/carbon nanocomposite thin films as compared to that of 82 F/g for pure magnetite thin films in Na2SO4 aqueous electrolyte.

关键词： Magnetite Magnetite/carbon nanocomposite Native sago starch Specific capacitance

Grade-4 commercially pure titanium with ultrahigh strength achieved by twinning-induced grain refinement through cryogenic deformation

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Journal of Materials Science & Technology 2021年第7期66卷 193-201页

作者： Seong-Woo Choi Jae sukjeong Jong Woo Won Jae Keun Hong Yoon suk Choi Titanium Department.Korea Institute of Materials Science Changwon51508Republic of Korea School of Materials Science and Engineering Pusan National UniversityPusan.46241Republic of Korea Materials and Manufacturing Development Team Doosan Heavy Industries and ConstructionChangwon51711Republic of Korea

The yield strength of commercially pure(CP) Ti of ASTM grade 4, the strongest among all the CP-Ti grades, is too low for structural applications that require high-strength materials. Here, we demonstrate the strengthening of grade-4 CP Ti by cryogenic-temperature rolling(CTR), which enables deformation twinning in grade-4 CP Ti to achieve twinning-induced grain refinement. CTR activated {11.22} twinning and {10.12} twinning, which are the most common twinning systems in pure Ti, whereas room-temperature rolling(RTR) did not activate any twinning system. CTR with imposing an area reduction of just 30% significantly increased the yield strength of the CP Ti to 946 MPa, which is not achievable through typical processes performed at or above room temperature and is comparable to that of commercial Ti-6 Al-4 V. The significant increase in strength was due to microstructural strengthening caused by twinning-induced grain refinement, combined with dislocation accumulation. In contrast to RTR, CTR greatly increased the stress concentration at grain boundaries(GBs), which caused the unusual activation of twinning in the grade-4 CP Ti by facilitating twin nucleation at GBs. The stress concentration increased because CTR activated the slip to a lesser extent compared to RTR, thereby reducing the strain compatibility between neighboring grains. These results will contribute to development of ultrahigh-strength CP Ti and may thereby extend its use to structural applications that require high-strength materials.

关键词： Titanium Twinning Cryogenic deformation Grain refinement Tensile properties

Robust Formation Maneuvers Through Sliding Mode for Multi-agent Systems With Uncertainties

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 342-351页

作者： Dianwei Qian Chengdong Li suk Gyu Lee Chao Ma School of Control and Computer Engineering North China Electric Power University School of Information and Electrical Engineering Shandong Jianzhu University Department of Electrical Engineering Yeungnam University

This paper develops a robust control method for formation maneuvers of a multi-agent system. The multi-agent system is leader-follower-based, where the graph theory is utilized to describe the information exchange among the agents. The control method is exercised via sliding mode methodology where each agent is subjected to uncertainties. The technique of nonlinear disturbance observer is adopted in order to overcome the adverse effects of the uncertainties. Assuming that the uncertainties have an unknown bound, the formation stability conditions are investigated according to a given communication topology. In the sense of Lyapunov, not only the formation maneuvers of the multi-agent system have guaranteed stability, but the desired formations of the agents are also realized. Compared with other two control approaches, i.e., the basic sliding mode approach and the fuzzy sliding mode approach, some numerical results are presented to illustrate the effectiveness, performance and validity of the robust control method for formation maneuvers in the presence of uncertainties.

关键词： Formation control multi-agent systems nonlinear disturbance observer sliding mode uncertainties

Graphene quantum dots/Ni(oh)_(2) nanocomposites on carbon cloth as a binder-free electrode for supercapacitors

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Journal of Materials Science & Technology 2020年第23期58卷 73-79页

作者： Yiwen Hong Jingli Xu Jin suk Chung Won Mook Choi School of Chemical Engineering University of Ulsan93 Daehak-ro Nam-guUlsan44610Republic of Korea College of Chemistry and Chemical Engineering Shanghai University of Engineering ScienceLongTeng Road 333201620ShanghaiPR China

Graphene quantum dots(GQDs)/Ni(oh)_(2) composites on carbon cloth(G-NH//CC) are prepared through simple hydrothermal reactions. The resulting G-NH//CC is employed as a binder-free electrode of supercapacitors. Due to the enhanced electrical conductivity and efficient ion transport by the addition of GQDs, the G-NH//CC electrode exhibits enhanced electrochemical performances. Specifically, the GNH//CC delivers a maximum specific capacitance of 1825 F g^(-1) at a current density of 1 A g^(-1) as well as a good cycle stability of 83.5 % capacity retention after 8000 cycles. Additionally, all-solid-state symmetric supercapacitor(SSC) is assembled with G-NH//CC composites as both positive and negative *** fabricated SSC exhibits a high energy density of 80.8 Wh kg^(-1)at a power density of 2021 W kg^(-1). The present study provides a facile and efficient strategy to prepare high-performance electrode materials for advanced electrochemical energy storage devices.

关键词： Graphene quantum dots Ni(oh)_(2) Carbon clothes Symmetric supercapacitors

Detection of Apple Marssonina Blotch with PLSR, PCA, and LDA Using Outdoor Hyperspectral Imaging

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光谱学与光谱分析 2020年第4期40卷 1309-1314页

作者： Soo Hyun Park Youngki Hong Mubarakat Shuaibu Sangcheol Kim Won suk Lee Department of Agricultural and Biological Engineering University of FloridaGainesvilleFL 32611United States Department of Agricultural Engineering National Academy of Agricultural ScienceRDAJeonju 55365South Korea Smart Farm Research Center Korea Institute of Science and Technology(KIST)Gangneung-siGangwon-do 25451South Korea

In this study, hyperspectral images were used to detect a fungal disease in apple leaves called Marssonina blotch(AMB). Estimation models were built to classify healthy, asymptomatic and symptomatic classes using partial least squares regression(PLSR), principal component analysis(PCA), and linear discriminant analysis(LDA) multivariate methods. In general, the LDA estimation model performed the best among the three models in detecting AMB asymptomatic pixels, while all the models were able to detect the symptomatic class. LDA correctly classified asymptomatic pixels and LDA model predicted them with an accuracy of 88.0%. An accuracy of 91.4% was achieved as the total classification accuracy. The results from this work indicate the potential of using the LDA estimation model to identify asymptomatic pixels on leaves infected by AMB.

关键词： Apple Marssonina blotch Hyperspectral imaging PLSR PCA LDA

Ultrasonographic findings of re-epithelialized skin after partial-thickness burns

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Burns & Trauma 2018年第3期6卷 219-227页

作者： Jong Dae Kim suk Joon oh Sun Gyu Kim Song Vogue Ahn Yu Jin Jang Ban Seok Yang Ji Yun Jeong Kwang Jo Kim Department of Burn Reconstructive Surgery Bestian Seoul HospitalDogok-ro 429Gangnam-guSeoulRepublic of Korea Department of Health Convergence Ewha Womans UniversityEwhayeodae-gil 52Seodaemun-guSeoulRepublic of Korea Department of Radiology Bestian Seoul HospitalDogok-ro 429Gangnam-guSeoulRepublic of Korea.4Department of General SurgeryBestian Seoul HospitalSeoulRepublic of Korea

Background:This study aimed to investigate the difference between ultrasonographic findings of normal skin and those of re-epithelialized skin after partial-thickness burns and to evaluate the relationship between these findings and clinical outcomes. Methods:This study retrospectively analysed the ultrasound images of re-epithelialized skin after partial-thickness burns and contralateral normal skin from January 2016 to December 2016. A total of 155 lesions from 148 patients were analysed with ultrasound images, and healing time was documented. The scar status of each lesion was evaluated through medical records and photographs. We analysed the difference in ultrasonographic findings between normal skin and re-epithelialized skin after partial-thickness burns and statistically analysed the relationship between healing time, scar status and ultrasonographic findings. Results: The re-epithelialized skin after partial-thickness burns was significantly thicker than the contralateral normal skin, and the echogenicity was significantly lower. The ultrasound images of the re-epithelialized skin after partial-thickness burns showed the characteristic findings of low-echogenic bands (LEB), and the proportion of LEB thickness is strongly correlated with healing time. In the multivariate analysis of scar status, only the proportion of LEB thickness was statistical y significant. Conclusion:In this study, we found that there were ultrasonographic differences between re-epithelialized skin after partial-thickness burns and normal skin and that an LEB of varying thickness was formed after re-epithelialization. The thickness of the LEB in re-epithelialized skin after partial-thickness burns increased with healing time and was related to scar status.

关键词： Partial-thickness burn Ultrasonography Low-echogenic band Healing time Scar Re-epithelialized skin

Applying Job Shop Scheduling to SMEs Manufacturing Platform to Revitalize B2B Relationship

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Computers, Materials & Continua 2023年第3期74卷 4901-4916页

作者： Yeonjee Choi Hyun suk Hwang Chang Soo Kim Department of Information Systems Pukyong National UniversityBusan608737Korea Research Center Hanyoung DSInc.Seoul07600Korea

A small and medium enterprises(SMEs)manufacturing platform aims to perform as a significant revenue to SMEs and vendors by providing scheduling and monitoring *** optimal job shop scheduling is generated by utilizing the scheduling system of the platform,and a minimum production time,i.e.,makespan decides whether the scheduling is optimal or *** scheduling result allows manufacturers to achieve high productivity,energy savings,and customer *** in Industry 4.0 requires dynamic,uncertain,complex production environments,and customer-centered *** paper proposes a novel method for solving the difficulties of the SMEs manufacturing by applying and implementing the job shop scheduling system on a SMEs manufacturing *** primary purpose of the SMEs manufacturing platform is to improve the B2B relationship between manufacturing companies and *** platform also serves qualified and satisfactory production opportunities for buyers and producers by meeting two key factors:early delivery date and fulfillment of processing as many orders as *** genetic algorithm(GA)-based scheduling method results indicated that the proposed platform enables SME manufacturers to obtain optimized schedules by solving the job shop scheduling problem(JSSP)by comparing with the real-world data from a textile weaving factory in South *** proposed platform will provide producers with an optimal production schedule,introduce new producers to buyers,and eventually foster relationships and mutual economic interests.

关键词： Manufacturing platform job shop scheduling problem(JSSP) genetic algorithm optimization textile process

Stability of PAC(Psy-2A-Crt I) gene and agronomic traits in the F_(2:3) of IR36/PAC transgenic plants

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Journal of Integrative Agriculture 2015年第6期14卷 1163-1170页

作者： Hyun suk Lee Gihwan Yi Kyung Min Kim Division of Plant Biosciences School of Applied Biosciences College of Agriculture and Life Science Kyungpook National University Department of Farm Management College of Agriculture and Life Science Kyungpook National University

This study was carried out to evaluate the expression of yellow endosperm color in the progeny of Psy-2A-Crt I（β-carotene gene, PAC） transgenic plants crossed with IR36. The selected 25 lines of F2 progeny exhibited stable expression of yellow endosperm color and high agronomic characteristics. IR36 and PAC transgenic plant of the grain length, width and ratio showed the same tendency of normal distribution. For progeny selection, colorimeters were as employed to distinguish differing visible colors. Correlation analysis was conducted to investigate the relationship between b＊ value and the expression of specific genes. b＊ value was associated with the relative expression of the PAC-Rev and MAR product by real-time PCR and t-test revealed significant difference. Based on this study, correlation between colorimetric values and real-time PCR was effective to detect gene expression. Yellow endosperm progenies represent a new genetic pool that might be useful to increase the genetic diversity of yellow endosperm rice.

关键词： transgenic agronomic crossed yellow breeding panicle length distinguish phenotype Correlation

Lentinula edodes extract inhibits matrix metalloproteinase expression and increases typeⅠprocollagen expression via the p38 MAPK/c-Fos signaling pathway in ultraviolet A and B-irradiated HaCaT keratinocytes

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Asian Pacific Journal of Tropical Biomedicine 2021年第4期11卷 164-173页

作者： Jung Im Lee Jung Hwan oh Fatih Karadeniz So Young Park Hye Ran Kim Hyun Jin Jo Kyung Im Jung Byung-Jin Jeon Chang-suk Kong Marine Biotechnology Center for Pharmaceuticals and Foods Silla UniversityBusan 46958Korea Department of Food and Nutrition College of Medical and Life SciencesSilla UniversityBusan 46958Korea Ocean Fisheries and Bio Center Busan technoparkBusan 46048Korea

Objective:To determine the effect of Lentinula edodes extract on ultraviolet(UV)A and UVB-induced changes in matrix metalloproteinase(MMP)and type I procollagen expression using human immortalized HaCaT ***:Lentinula edodes ethanol extract(LEE)was obtained by extraction with 80%ethanol for 4 h at 80℃.Effect of LEE on UVinduced alteration on the expression and production of MMPs and type I procollagen in keratinocytes was investigated using ELISA,RT-PCR,and Western blotting *** determine the underlying mechanism of LEE-mediated effects,mitogen-activated protein kinase(MAPK)and activator protein 1 signaling pathways were analysed by Western blotting ***:LEE significantly inhibited the expression of MMP-1 and MMP-9 and increased the expression of type I procollagen in UVA and UVB-irradiated HaCaT *** phosphorylation levels of p38 were significantly inhibited by LEE whereas it did not affect c-Jun N-terminal kinase and extracellular signal-regulated kinase *** of p38 phosphorylation was also accompanied by downregulation of UVA and UVB-induced increase in ***:LEE effectively inhibits the expression of MMP-1 and MMP-9 and increases type I procollagen production through the p38 MAPK/c-Fos signaling pathway in UVA and UVB-irradiated HaCaT *** findings suggest that Lentinula edodes may be developed as a cosmetic material to suppress UV exposuremediated skin aging.

关键词： Lentinula edodes Ultraviolet Matrix metalloproteinases TypeⅠprocollagen Ha Ca T