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Point-defect engineering of nanoporous CuBi_(2)O_(4) photocathode via rapid thermal processing for enhanced photoelectrochemical activity

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Journal of Energy Chemistry 2022年第8期31卷 201-209,I0007页

作者： Li Qu Runfa Tan Arumugam Sivanantham Min Je Kang Yoo Jae Jeong dong Hyun Seo Sungkyu kim In Sun Cho Department of Materials Science&Engineering Ajou UniversitySuwon 16499South Korea Department of Energy Systems Research Ajou UniversitySuwon 16499South Korea Department of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul 05006South Korea

Engineering point defects such as metal and oxygen vacancies play a crucial role in manipulating the electrical,optical,and catalytic properties of oxide semiconductors for solar water ***,we synthesized nanoporous CuBi_(2)O_(4)(np-CBO)photocathodes and engineered their surface point defects via rapid thermal processing(RTP)in controlled atmospheres(O_(2),N_(2),and vacuum).We found that the O_(2)-RTP treatment of np-CBO increased the charge carrier density effectively without hampering the nanoporous morphology,which was attributed to the formation of copper vacancies(VCu).Further analyses revealed that the amounts of oxygen vacancies(Vo)and Cu^(1+)were reduced simultaneously,and the relative electrochemical active surface area increased after the O_(2)-RTP ***,the point defects(VC_(u),Cu^(1+),and Vo)regulated np-CBO achieved a superb water-splitting photocurrent density of-1.81 m A cm^(-2) under simulated sunlight illumination,which is attributed to the enhanced charge transport and transfer properties resulting from the regulated surface point ***,the reversibility of the formation of the point defects was checked by sequential RTP treatments(O_(2)-N_(2)-O_(2)-N_(2)),demonstrating the strong dependence of photocurrent response on the RTP ***,the surface point defect engineering via RTP treatment in a controlled atmosphere is a rapid and facile strategy to promote charge transport and transfer properties of photoelectrodes for efficient solar water-splitting.

关键词： Nanoporous Copper bismuth oxide Rapid thermal processing Copper vacancy Charge transport

Probabilistic Distribution of the Maximum Wave Heigh

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China Ocean Engineering 2014年第5期28卷 579-586页

作者： dong Hyawn kim Taerim kim Department of Ocean Science and Engineering Kunsan National University

A new method of treating maximum wave height as a random variable in reliability analysis of breakwater caissons isproposed. The maximum wave height is expressed as the significant wave height multiplied by the so-called wave height *** proposed wave height ratio is a type of transfer function from the significant wave height to the maximum wave *** the condition of a breaking wave, the ratio is intrinsically nonlinear. Therefore, the probability density function for thevariable cannot be easily defined. In this study, however, it can be derived from the relationship between the maximum andsignificant waves in a nonbreaking environment. Some examples are shown to validate the derived probability density functionfor the wave ratio parameter. By introducing the wave height ratio into reliability analysis of caisson breakwater, the maximumwave height can be used as an independent and primary random variable, which means that the risk of caisson failure during itslifetime can be evaluated realistically.

关键词： maximum wave height wave height ratio reliability caisson breakwater wave breaking

Induced noise of impeller stuck and passive rotation state in multi-stage pump without power drive under natural flow conditions

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Journal of Hydrodynamics 2023年第5期35卷 1008-1026页

作者： Run-ze Zhou Hou-lin Liu Ru-nan Hua Liang dong kim Tiow Ooi Cui Dai Si-yuan Hu Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang212013China National Research Center of Pumps Jiangsu UniversityZhenjiang212013China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingaporeSingapore Wuhan Second Ship Design and Research Institute Wuhan430060China School of Energy and Power Engineering Jiangsu UniversityZhenjiang212013China

The natural flow cooling strategy is commonly employed in modern high-speed vessels and nuclear-powered submarines. These vessels rely on the energy generated by their own speed to drive the cooling system and supply cooling water to the condenser. The circulating pump, which operates without a motor drive under natural flow conditions, is a large resistance component in the cooling system. However, it is also the primary noise source, significantly impacting the vessel’s safe operation and acoustic stealth performance. This study investigates the induced noise characteristics of a multi-stage pump under natural flow conditions by experiment, computational fluid dynamics (CFD), and acoustic finite element method. The analysis encompasses the distribution of the flow field, variations in acoustic power, spectral features of flow-induced noise, and directivity of external field radiation noise under different natural flow conditions. The results show that the acoustic power distribution is correlated with the flow field. When the impeller is stuck, the noise sources primarily concentrate in the flow separation area at the blade’s leading edge, the interface area between the impeller and the guide vane, and the flow shock area inside the guide vane. Conversely, when the impeller rotates passively, the blade wake area has a higher acoustic power. The flow noise spectrum under natural flow conditions mainly exhibits broadband and discrete characteristics. Additionally, the pump structure influences the external field radiation noise, and its directivity varies with different flow rates and characteristic frequencies. This study provides valuable insights into optimal design to reduce the noise of the circulating pump in the vessel’s natural flow cooling system. It is essential for ensuring the safe operation and acoustic stealth performance of high-speed vessels and nuclear-powered submarines.

关键词： Natural flow condition multi-stage pump flow induced noise acoustic power radiation noise directivity

Fast Tunable Wavelength Sources Based on the Laser Diode Array

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光学学报 2003年第S1期23卷 483-484页

作者： Sung-Chan Cho Hyun Ha Hong Byoung-whi kim WPON team ETRI Daejeon 305-350 KoreaWPON team ETRI Daejeon 305-350 KoreaWPON team ETRI Daejeon 305-350 Korea

We report a demonstration of a fast wavelength tunable source (TWS) based on the laser diode array coupled to the arrayed waveguide grating (AWG) multiplexer. The switching and optical characteristics of TWS make it a... 详细信息

关键词： AWG as for Fast Tunable Wavelength Sources Based on the Laser Diode Array on than be mode LD MWL of

Experimental Study on the Inlet Fogging System Using Two-Fluid Nozzles

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Journal of Thermal Science 2010年第2期19卷 132-135页

作者： Abhilash Suryan dong Sun kim Heuy dong kim School of Mechanical Engineering Andong National University FMTRC Daejoo Machinery Co.

Large-capacity compressors in industrial plants and the compressors in gas turbine engines consume a considerable amount of *** compression work is a strong function of the ambient air *** increase in compression work presents a significant problem to utilities,generators and power producers when electric demands are high during the hot *** many petrochemical process industries and gas turbine engines,the increase in compression work curtails plant output,demanding more electric power to drive the *** way to counter this problem is to directly cool the inlet *** fogging is a popular means of cooling the inlet air to air *** the present study,experiments have been performed to investigate the suitability of two-fluid nozzle for inlet *** air is used as the driving working gas for two-fluid nozzle and water at ambient conditions is dragged into the high-speed air jet,thus enabling the entrained water to be atomized in a very short distance from the exit of the two-fluid *** air supply pressure is varied between 2.0 and 5.0 bar and the water flow rate entrained is *** flow visualization and temperature and relative humidity measurements are carried out to specify the fogging characteristics of the two-fluid nozzle.

关键词：雾化喷嘴双流体喷雾系统实验燃气涡轮发动机气压缩机水流量测量石油化工过程

Expected Sliding Distance of Vertical Slit Caisson Breakwater

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China Ocean Engineering 2017年第3期31卷 317-321页

作者： dong Hyawn kim Department of Ocean Science & Engineering Ktmsan National University Daehakro 558 Kunsan Jeormuk 54150 Republic of Korea

Evaluating the expected sliding distance of a vertical slit caisson breakwater is proposed. Time history for the wave load to a vertical slit caisson is made. It consists of two impulsive wave pressures followed by a smooth sinusoidal pressure. In the numerical analysis, the sliding distance for an attack of single wave was shown and the expected sliding distance during 50 years was also presented. Those results were compared with a vertical front caisson breakwater without slit. It was concluded that the sliding distance of a vertical slit caisson may be over-estimated if the wave pressure on the caisson is evaluated without considering vertical slit.

关键词： breakwater vertical slit caisson expected sliding distance reliability performance based design

Sensors-Based Ambient Assistant Living via E-Monitoring Technology

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Computers, Materials & Continua 2022年第12期73卷 4935-4952页

作者： Sadaf Hafeez Yazeed Yasin Ghadi Mohammed Alarfaj Tamara al Shloul Ahmad Jalal Shaharyar Kama dong-Seong kim Department of Computer Science Air UniversityIslamabad44000Pakistan Department of Computer Science and Software Engineering Al Ain UniversityAl Ain15551UAE Department of Electrical Engineering King Faisal UniversityAl-Ahsa31982Saudi Arabia Department of Humanities and Social Science Al Ain UniversityAl Ain15551UAE Department of IT Convergence Engineering Kumoh National Institute of TechnologyGumiKorea

Independent human living systems require smart,intelligent,and sustainable online monitoring so that an individual can be assisted *** from ambient assisted living,the task of monitoring human activities plays an important role in different fields including virtual reality,surveillance security,and human interaction with *** systems have been developed in the past with the use of various wearable inertial sensors and depth cameras to capture the human *** this paper,we propose multiple methods such as random occupancy pattern,spatio temporal cloud,waypoint trajectory,Hilbert transform,Walsh Hadamard transform and bone pair descriptors to extract optimal features corresponding to different human *** features sets are then normalized using min-max normalization and optimized using the Fuzzy optimization ***,the Masi entropy classifier is applied for action recognition and *** have been performed on three challenging datasets,namely,UTDMHAD,50 Salad,and *** experimental evaluation,the proposed novel approach of recognizing human actions has achieved an accuracy rate of 90.1%with UTD-MHAD dataset,90.6%with 50 Salad dataset,and 89.5%with CMU-MMAC *** experimental results validated the proposed system.

关键词： Classification algorithm human action recognition motion sensors machine learning Masi entropy

Neurocircuitry of Predatory Hunting

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Neuroscience Bulletin 2023年第5期39卷 817-831页

作者： Zheng-dong Zhao Li Zhang Xinkuan Xiang Daesoo kim Haohong Li Peng Cao Wei L.Shen School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China Boston Children's Hospital Harvard Medical SchoolBostonMA 02115USA National Institute of Biological Sciences(NIBS) Beijing 102206China Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan 430074China MoE Key Laboratory for Biomedical Photonics Collaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnoiogyWuhan 430074China Department of Cognitive Brain Science Korea Advanced Institute of Science&TechnologyDaejeon 34141South Korea MOE Frontier Research Center of Brain&Brain-machine Integration School of Brain Science and Brain MedicineZhejiang UniversityHangzhou 310058China Affiliated Mental Health Centre and Hangzhou Seventh People's Hospital Zhejiang University School of MedicineHangzhou 310013China

Predatory hunting is an important type of innate behavior evolutionarily conserved across the animal *** is typically composed of a set of sequential actions,including prey search,pursuit,attack,and *** behavior is subject to control by the nervous *** studies used toads as a model to probe the neuroethology of hunting,which led to the proposal of a sensory-triggered release mechanism for hunting *** recent stud-ies have used genetically-trackable zebrafish and rodents and have made breakthrough discoveries in the neuroethol-ogy and neurocircuits underlying this ***,we review the sophisticated neurocircuitry involved in hunting and summarize the detailed mechanism for the circuitry to encode various aspects of hunting neuroethology,including sensory processing,sensorimotor transformation,motivation,and sequential encoding of hunting *** also discuss the overlapping brain circuits for hunting and feeding and point out the limitations of current *** propose that hunting is an ideal behavioral paradigm in which to study the neuroethology of motivated behaviors,which may shed new light on epidemic disorders,including bingeeating,obesity,and obsessive-compulsive disorders.

关键词： Predatory hunting Neurocircuits Sensory processing Sensorimotor transformation Appetitive motivation Sequential encoding

Devastating complication of negative pressure wound therapy after deep inferior epigastric perforator free flap surgery:A case report

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World Journal of Clinical Cases 2023年第1期11卷 143-149页

作者： SooA Lim dong Yun Lee BumSik kim Jung Soo Yoon Yea Sik Han SuRak Eo Department of Plastic and Reconstructive Surgery DongGuk University Medical CenterGoYang 10326South Korea

BACKGROUND Thermal injuries on free transferred or replanted tissues resulting from loss of sensibility are an infrequent *** require immediate and appropriate management before they progress to an irreversible *** negative pressure wound therapy(NPWT)can prevent wound progression by increasing microcirculation,the inappropriate application of NPWT on complicationthreatened transferred and replanted tissues can induce an adverse *** SUMMARY A 48-year-old woman who underwent immediate breast reconstruction with a deep inferior epigastric artery perforator free *** applying a heating pad directly to the flap site,she sustained a deep second to third-degree contact burn over 30%of the transferred flap on postoperative 7 *** the necrotic changes had progressed,we applied an NPWT dressing over the burned area after en-bloc debridement of the transferred tissues on postoperative 21 *** 4 d of NPWT application,the exposed fatty tissues of the flap changed to dry and browncolored necrotic *** further debridement,we noted that the wound gradually reached total necrosis with a collapsed vascular pedicle of deep inferior epigastric *** Although NPWT has been shown to be successful for treating various wound types,the significant risk of NPWT application in short-lasting reconstructed flap wounds after thermal injury should be reminded.

关键词： Negative Pressure Wound Therapy Complications Breast reconstruction Deep inferior epigastric artery perforator Free flap Burn injury Case report