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Factor analysis of recent major heatwaves in East Asia

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Geoscience Frontiers 2024年第1期15卷 374-383页

作者： Arim Yoon Jeongwon Kim Jooyeop Lee Hyun Min Sung Je-Woo Hong Seung-Ki Min Junhong Lee Jinkyu Hong Ecosystem-Atmosphere process Laboratory Department of Atmospheric SciencesYonsei UniversitySeoul 03722Republic of Korea National Institute of Meteorological Sciences Jeju 63568Republic of Korea Korea Adaptation Center for Climate Korea Environment InstituteSejong 30121Republic of Korea division of Environmental Science and engineering Pohang University of Science and TechnologyPohang 37673Republic of Korea Max Planck Institute for Meteorology Hamburg 20146Germany Institute for Convergence Research and Education in Advanced Technology Yonsei UniversitySeoulRepublic of Korea

Heatwaves(HWs)present a major hazard to our society and more extreme heatwaves are expected with future climatic ***,it is important to improve our understanding of the underlying processes that drive HWs,in order to boost our socioeconomic-ecological *** this study,we quantified the influences of key driving factors(large-scale atmospheric circulation,soil moisture,and sea surface temperature)and their synergies on recent heatwaves in East *** conducted a factor separation analysis for three recent HW events by constraining the key factors in the regional Weather Research and Forecasting model with their climatologies or pseudo-observations in different *** study showed distinct spatial variations in the HW-controlling factors in East *** synergistic interaction of large-scale circulation and soil moisture was the most important factors in the 2013 Chinese *** the 2018 HWs in Korea and Japan,the same stagnant large-scale atmospheric circulation played a dominant role in driving the HW *** land-atmosphere coupling via soil moisture,its interaction with circulation,and SST exhibited stronger influences during the Korean HW than the Japanese *** analysis also revealed temporal variations in the factors driving Korean and Chinese HWs due to typhoon passage and other multiple processes over heterogeneous surfaces(i.e.,topographically induced Foehn winds,large-scale warm advection from the warm ocean,spatial differences in soil moisture).Our findings suggest that future heatwave-related studies should consider interactive contributions of key factors,their interplay with surface heterogeneities of complex terrain.

关键词： Heatwave East Asia Large-scale circulation Soil moisture Sea surface temperature Synergistic impacts

Numerical analysis of the return flow solar air heater(RF-SAH)with assimilation of V-type artificial roughness

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Energy and Built Environment 2024年第2期5卷 185-193页

作者： Prashant Raturi Hemlata Deolal Sanjeev Kimothi Department of Mechanical engineering Swami Rama Himalayan University Dehradun248140India Department of Mechanical engineering DIT UniversityDehradun248001India division of Research&Innovation Dept.of PhysicsUttaranchal University248007India

A novel design of Return Flow Solar Air Heater(RFSAH)with different arrangements of baffles especially V-Type Artificial roughness is simulated and numerically analyzed with energy balance *** enhance the effectiveness of baffles,numerous studies have been *** performance of the RFSAH is studied in terms of thermal efficiency,thermo-hydraulic efficiency,and optimization of baffle *** thermal efficiency and thermo-hydraulic efficiency are found in RFSAH with baffle on both sides of the absorber plate and mass flow rate above 0.2kg/*** analysis of the influencing parameters is carried out and reported the best performance of the system on selective geometrical parameters(ψ=0.7,β=20%,e/H=1,p/e=0.8,α=60°).The results obtained from the present model are validated with the published experimental results and have been found in quite reasonable agreement with an average error of 16.45%.thermal and Thermohydraulic efficiency of RFSAH with a baffle on both sides of the absorber plate is maximum among baffles below,above,and on both sides of the absorber *** is observed that the thermal efficiency of RFSAH is greater than *** proposed optimum baffles roughness is suggested to increase the air upholding time period for more efficient output.

关键词： Numerical analysis Energy Balance Equations thermal Efficiency Return flow solar air heater V-baffles

Development and evaluation of a vision driven sensor for estimating fuel feeding rates in combustion and gasification processes

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Energy and AI 2024年第1期15卷 44-54页

作者： YngveÖren Alexey Sepman Ehsan Fooladgar Fredrik Weiland Henrik Wiinikka RISE AB Box 726 SE-94128PiteåSweden Energy engineering Division of Energy ScienceLuleåUniversity of TechnologySE 97187LuleåSweden

A machine vision driven sensor for estimating the instantaneous feeding rate of pelletized fuels was developed and tested experimentally in combustion and gasification *** feeding rate was determined from images of the pellets sliding on a transfer chute into the *** the images the apparent area and velocity of the pellets were *** was determined by a segmentation model created using a machine learning framework and velocities by image registration of two subsequent *** measured weight of the pelletized fuel passed through the feeding system was in good agreement with the weight estimated by the *** observed variations in the fuel feeding correlated with the variations in the gaseous species concentrations measured in the reactor core and in the *** the developed sensor measures the ingoing fuel feeding rate prior to the reactor,its signal could therefore help improve process control.

关键词： Fuel feeding process monitoring Image processing Neural network Combustion Gasification

Organ Abscission in Plants: With Special Emphasis on Bell Pepper

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1467-1484页

作者： Ramiro Reyes-Castro Héctor G.Núñez-Palenius Juan I.Valiente-Banuet María E.Sosa-Morales Blanca E.Orosco-Alcalá Rafael Guzmán-Mendoza Graciela M.L.Ruiz-Aguilar Rogelio Costilla-Salazar Life Sciences division Universidad de GuanajuatoIrapuato36500México School of engineering and Sciences Tecnologico de MonterreyQuerétaro76130México

Bell pepper(Capsicum annuum L.),along with potato and tomato,is one of the three most cultivated vegetables in the *** pepper is worldwide accepted due to its characteristics of color,smell,ﬂavor,and *** pepper is also considered a nutritious food due to its vitamin and antioxidant *** Mexico,bell pepper production has a high value because it is grown for the international markets,particularly the United States of ***,the abscission ofﬂowers and fruits is a factor that limits the yield,hinders the planning of activities,and causes a variation in the prices of *** to the importance of this process,in this work we did a bibliometric analysis and literature review of scientiﬁc advances for the understanding of the abscission pro-cess in plants,and in particular for the bell ***,we introduce new perspectives that would help direct future research about organ abscission in ***,the lack of research that would further clarify abscis-sion process in the bell pepper plant is discussed.

关键词： Capsicum annuum abscission zone plant growth regulators environmental factors

Wellbore-heat-transfer-model-based optimization and control for cooling downhole drilling fluid

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Petroleum Science 2024年第3期21卷 1955-1968页

作者： Chao Wang He Liu Guo-Wei Yu Chen Yu Xian-Ming Liu Peng Huang Yangtze University Jingzhou434023HubeiChina State Key Laboratory of Petroleum Resources and engineering China University of Petroleum(Beijing)Beijing2249China CNPC Bohai Drilling engineering Co. LtdTianjin300280China Exploration Development and Construction engineering division of PetroChina Jidong Oilfield Company Tangshan63200HebeiChin Henan University of Urban Construction Pingdingshan467036HenanChina

To address the two critical issues of evaluating the necessity of implementing cooling techniques and achieving real-time temperature control of drilling fluids underground in the current drilling fluid cooling technology,we first established a temperature and pressure coupled downhole heat transfer model,which can be used in both water-based and oil-based drilling ***,fourteen factors,which could affect wellbore temperature,were *** on the standard deviation of the downhole temperature corresponding to each influencing factor,the influence of each factor was *** influencing factors that can be used to guide the drilling fluid's cooling technology were drilling fluid thermal conductivity,drilling fluid heat capacity,drilling fluid density,drill strings rotation speed,pump rate,viscosity,ROP,and injection *** nondominated sorting genetic algorithm was used to optimize these six parameters,but the optimization process took 182 *** these eight parameters'influence rules with the nondominated sorting genetic algorithm can reduce the optimization time to 108 ***,the downhole temperature has been demonstrated to increase with the inlet temperature increasing linearly under quasi-steady *** this law and PID,the downhole temperature can be controlled,which can reduce the energy for cooling the surface drilling fluid and can ensure the downhole temperature reaches the set value as soon as possible.

关键词： Drilling Cooling Influencing factors Analysis Optimization Control

Distributed Resource Allocation in Dispersed Computing Environment Based on UAV Track Inspection in Urban Rail Transit

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Computers, Materials & Continua 2024年第7期80卷 643-660页

作者： Tong Gan Shuo Dong Shiyou Wang Jiaxin Li division of Consulting Beijing Metro Consultancy Corporation Ltd.Beijing100037China Department of Computer and Communication engineering University of Science and Technology BeijingBeijing100083China

With the rapid development of urban rail transit,the existing track detection has some problems such as low efficiency and insufficient detection coverage,so an intelligent and automatic track detectionmethod based onUAV is urgently needed to avoid major safety *** the same time,the geographical distribution of IoT devices results in the inefficient use of the significant computing potential held by a large number of *** a result,the Dispersed Computing(DCOMP)architecture enables collaborative computing between devices in the Internet of Everything(IoE),promotes low-latency and efficient cross-wide applications,and meets users’growing needs for computing performance and service *** paper focuses on examining the resource allocation challenge within a dispersed computing environment that utilizes UAV inspection ***,the system takes into account both resource constraints and computational constraints and transforms the optimization problem into an energy minimization problem with computational *** Markov Decision process(MDP)model is employed to capture the connection between the dispersed computing resource allocation strategy and the system ***,a method based on Double Deep Q-Network(DDQN)is introduced to derive the optimal ***,an experience replay mechanism is implemented to tackle the issue of increasing *** experimental simulations validate the efficacy of the method across various scenarios.

关键词： UAV track inspection dispersed computing resource allocation deep reinforcement learning Markov decision process

Superconducting joints using reacted multifilament MgB_(2)wires:A technology toward cryogen-free MRI magnets

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Journal of Magnesium and Alloys 2024年第1期12卷 159-170页

作者： Dipak Patel Akiyoshi Matsumoto Hiroaki Kumakura Yuka Hara Toru Hara Minoru Maeda Hao Liang Yusuke Yamauchi Seyong Choi Jung Ho Kim Md Shahriar A.Hossain School of Mechanical and Mining engineering The University of QueenslandSt LuciaQueensland 4072Australia National Institute for Materials Science(NIMS) 1-2-1 SengenTsukubaIbaraki 305-0047Japan Department of Electrical engineering and Kangwon High Magnetic Field Center Institute of Quantum Convergence TechnologyKangwon National UniversityGangwon 24341Republic of Korea Australian Institute for Bioengineering and Nanotechnology(AIBN) The University of QueenslandSt LuciaQueensland 4072Australia Department of Materials process engineering Graduate School of EngineeringNagoya UniversityNagoyaAichi 464-8603Japan Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongNorth WollongongNew South Wales 2500Australia

The development of superconducting joining technology for reacted magnesium diboride(MgB_(2))conductors remains a critical challenge for the advancement of cryogen-free MgB_(2)-based magnets for magnetic resonance imaging(MRI).Herein,the fabrication of superconducting joints using reacted carbon-doped multifilament MgB_(2)wires for MRI magnets is *** achieve successful superconducting joints,the powder-in-mold method was employed,which involved tuning the filament protection mechanism,the powder compaction pressure,and the heat treatment *** fabricated joints demonstrated clear superconducting-to-normal transitions in self-field,with effective magnetic field screening up to 0.5 T at 20 *** evaluate the interface between one of the MgB_(2)filaments and the MgB_(2)bulk within the joint,serial sectioning was conducted for the first time in this type of superconducting *** serial sectioning revealed space formation at the interface,potentially caused by the volume shrinkage associated with the MgB_(2)formation or the combined effect of the volume shrinkage and the different thermal expansion coefficients of the MgB_(2)bulk,the filament,the mold,and the sealing *** findings are expected to be pivotal in developing MgB_(2)superconducting joining technology for MRI magnet applications through interface engineering.

关键词： Mg B2 superconducting joint MgB_(2)conductor MRI applications Cryogen-free magnet Persistent-mode operation

Evolution of nonmetallic inclusions in 80-t 9CrMoCoB large-scale ingots during electroslag remelting process

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1525-1539页

作者： Shengchao Duan Min Joo Lee Yao Su Wangzhong Mu Dong Soo Kim Joo Hyun Park School of Mechanical and Materials engineering North China University of TechnologyBeijing 100144China Department of Materials Science and Chemical engineering Hanyang UniversityAnsan 15588Rep.of Korea Department of Materials Science and engineering KTH Royal Institute of TechnologyBrinellvägen 23Stockholm 10044Sweden Department of engineering Science and Mathematics Division of Materials ScienceLuleåUniversity of Technology97187 LuleåSweden Casting&Forging Business Unit Nuclear Business GroupDoosan EnerbilityChangwon 51711Rep.of Korea

In combination with theoretical calculations,experiments were conducted to investigate the evolution behavior of nonmetallic inclusions(NMIs)during the manufacture of large-scale heat-resistant steel ingots using 9CrMoCoB heat-resistant steel and CaF_(2)–CaO–Al_(2)O_(3)–SiO_(2)–B_(2)O_(3)electroslag remelting(ESR)-type slag in an 80-t industrial ESR *** main types of NMI in the consumable electrode comprised pure alumina,a multiphase oxide consisting of an Al_(2)O_(3)core and liquid CaO–Al_(2)O_(3)–SiO_(2)–MnO shell,and M_(23)C_(6)carbides with an MnS *** Al_(2)O_(3)and MnS inclusions had higher precipitation temperatures than the M_(23)C_(6)-type carbide under equilibrium and nonequilibrium solidification ***,inclusions can act as nucleation sites for carbide layer *** ESR process completely removed the liquid CaO–Al_(2)O_(3)–SiO_(2)–MnO oxide and MnS inclusion with a carbide shell,and only the Al_(2)O_(3)inclusions and Al_(2)O_(3)core with a carbide shell occupied the remelted *** M_(23)C_(6)-type carbides in steel were determined as Cr_(23)C_(6)based on the analysis of transmission electron microscopy *** substitution of Cr with W,Fe,or/and Mo in the Cr_(23)C_(6)lattice caused slight changes in the lattice parameter of the Cr_(23)C_(6)***,Cr_(21.34)Fe_(1.66)C_(6),(Cr_(19)W_(4)C_(6),Cr_(18.4)Mo_(4.6)C_(6),and Cr_(16)Fe_(5)Mo_(2)C_(6)can match the fraction pattern of Cr_(23)C_(6)*** Al_(2)O_(3)inclusions in the remelted ingot formed due to the reduction of CaO,SiO_(2),and MnO components in the liquid *** increased Al content in liquid steel or the higher supersaturation degree of Al_(2)O_(3)precipitation in the remelted ingot than that in the electrode can be attributed to the evaporation of CaF_(2)and the increase in CaO content in the ESR-type slag.

关键词： nonmetallic inclusion heat-resistant steel electroslag remelting M_(23)C_(6) carbide MnS inclusion supersaturation degree

ENERGY AND MASS TRANSPORT processES IN THE GRANULAR BED OF AN INDIRECTLY HEATED ROTARY KILN

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China Particuology 2004年第3期2卷 107-112页

作者： Wolfgang Klose Arndt-Peter Schinkel Institute of thermal engineering Thermodynamics Division University of Kassel 34109 Kassel GermanyInstitute of Thermal Engineering Thermodynamics Division University of Kassel 34109 Kassel Germany

The transport mechanisms of momentum, mass, species, and energy are investigated in detail for the ro-tary kiln process. The residence time prediction of the granular bed is well improved by considering different flow patterns in the drum. Introducing a mixed flow pattern of the basic slipping and slumping behaviour has the most important effect on the improvement of the residence time prediction. The granular bed is assumed to behave as a Bingham fluid in the active layer of the bed. The transport mechanisms of momentum, species, and energy are modelled on the basis of this assumption and using the kinetic gas theory. Additionally, a mathematical transformation is presented to save computa-tional time. The model results of the temperature field are in very good agreement with experimental data.

关键词： rotary kiln granular transport flow pattern heat transfer modelling