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Simulation of cooling channel rheocasting process of A356 aluminum alloy using three-phase volume averaging model

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中国有色金属学会会刊:英文版 2005年第2期15卷 389-394页

作者： T.Wang b.Pustal M.Abondano T.Grimmig a.bührig-polaczek M.Wu A.Ludwig Foundry Institute Aachen University of TechnologyAachenD-52072Germany Department of Metallurgy University of LeobenLeobenA-8700Austria Research Center of Foundry Engineering Dalian University of TechnologyDalian 116024China

The cooling channel process is a rehocasting method by which the prematerial with globular microstructure can be produced to fit the thixocasting process.A three-phase model based on volume averaging approach is proposed to simulate the cooling channel process of A356 Aluminum *** three phases are liquid,solid and air respectively and treated as separated and interacting continua,sharing a single pressure *** mass,momentum,enthalpy transport equations for each phase are *** developed model can predict the evolution of liquid,solid and air fraction as well as the distribution of grain density and grain *** effect of pouring temperature on the grain density,grain size and solid fraction is analyzed in detail.

关键词： A356 alloy modeling cooling channel three-phase semi-solid

Thixocasting combination spanners using stainless steel X39CrMo17

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中国有色金属学会会刊：英文版 2010年第S3期20卷 998-1004页

作者： M.büNCK E.SUbASIC a.bührig-polaczek K.JIANG S.MüNSTERMANN J.M.SCHNEIDER K.FICKERT H.J.GüNTHER Foundry Institute at RWTH Aachen University AachenGermany Materials Chemistry at RWTH Aachen University AachenGermany HAZET-Hermann Zerver GmbH & Co.KG RemscheidGermany PlaTeG GmbH SiegenGermany

Forging is state-of-the-art for producing hand tools on an industrial *** to high demands on the stiffness and the fracture toughness,high-strength forging steels were used to provide cavity-free components with high mechanical load ***,forging is a cost-effective mass production process but,in spite of all its advantages,it has its limitations,*** the freedom of ***,because of the extreme thermal loading(particularly with regard to permanent moulds) and the frequently unavoidable casting defects,hand tools are not *** means of thixocasting steel,technical difficulties can be reduced and new options are provided which allow the manufacturing of components with much higher complexity than that using *** near-net shape production,manufacturing steps and costs can be ***,steels,which are difficult to forge but nonetheless have high potential for specific applications(such as high strength or corrosion resistant steels),can also be *** cooperation with industrial partners,X39CrMo17 stainless steel combination spanners with 17 mm width across flats were *** dies were designed and optimized by simulation,the hot forming X38CrMoV5 tool steel as well as the molybdenum alloy TZM were selected as the tool *** dies were treated by a plasma nitriding process and subsequently coated with crystalline Al2O3 protective coatings by plasma-enhanced chemical vapor deposition(PECVD).During the experiments,combination spanners were successfully cast in the semi-solid *** parts were heat-treated to enhance the toughness of components,which was subsequently measured by a standardized torque ***,a hypothetical approach of a possible,industrial batch process was carried out using the simulation software MAGMAsoft.

关键词： thixocasting X39CrMo17 steel casting semi-solid MAGMAsoft simulation

Iron regulatory protein 1: the deadly switch of ferroptosis

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Neural Regeneration Research 2024年第3期19卷 477-478页

作者： Daniel a.bórquez Pamela J.Urrutia Center for biomedical Research Faculty of MedicineUniversidad Diego PortalesSantiagoChile Institute of Nutrition&Food Technology(INTA) Universidad de ChileSantiagoChile Geroscience Center for brain Health and Metabolism SantiagoChile

Ferroptosis,an iron-dependent cell death:Ferroptosis is a type of regulated necrosis,characterized by redox-active iron accumulation and increased free radical production derived by Fenton chemistry,that triggers oxidation of polyunsaturated fatty acids in phospholipids,loss of cellular membranes integrity,and leakage of intracellular contents.

关键词： integrity switch Iron

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镍基高温合金铸件界面的雀斑缺陷形成研究

镍基高温合金铸件界面的雀斑缺陷形成研究

Trust-based Intelligent Scheme for Mitigating black Hole Attacks in IoT

第十三届中国高温合金年会

作者：洪建平马德新王俊孙宝德 a.bührig-polaczek 上海交通大学金属基复合材料国家重点实验室 Foundry Institute RWTH University Aachen

本研究利用工业级birdgman真空定向凝固炉对CMSX-4和CM247 LC两种镍基高温合金内部多界面结构试样进行了定向凝固实验。结果表明,雀斑缺陷不仅在铸件外表面出现,同时也在铸件内部合金与陶瓷材料界面附近产生。分析认为糊状区内界面附近...

本研究利用工业级birdgman真空定向凝固炉对CMSX-4和CM247 LC两种镍基高温合金内部多界面结构试样进行了定向凝固实验。结果表明,雀斑缺陷不仅在铸件外表面出现,同时也在铸件内部合金与陶瓷材料界面附近产生。分析认为糊状区内界面附近的热熔质对流受到的阻力小于它在枝晶间区域的阻力,熔体在界面附近的流动性优于其在枝晶间区域。所以,铸件中界面的存在会增加高温合金铸件产生雀斑缺陷的风险。该实验结果为镍基高温合金单晶空心叶片内部可能产生雀斑缺陷提供了实验依据。

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来源： cnki会议评论

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Journal of Ha.bin Institute of Technology(New Series) 2024年第3期31卷 39-50页

作者： Feroz Khan a.b Weslin D Dilli babu M Mohammed Muzaffar Hussain Department of Computer Science Syed Hameedha Arts and Science CollegeKilakarai 623806Tamil NaduIndia Department of Information Technology Mohamed Sathak AJ College of EngineeringSiruseriChennai 603103India Department of Information Technology Panimalar Engineering CollegeChennai 600123India Department of Information Technology C.Abdul Hakeem College of Engineering and TechnologyMelvisharam 632509India

Internet of Things(IoT)networks are characterized by a multitude of wireless,interconnected devices that can dynamically join or exit the network without centralized administration or fixed infrastructure for *** multipath routing in IoT networks can improve data transmission reliability and load balancing by establishing multiple paths between source and destination nodes,these networks are susceptible to security threats due to their wireless *** security solutions developed for conventional networks are often ill-suited to the unique challenges posed by IoT *** response to these challenges,this paper proposes the integration of the Ad hoc On-demand Multipath Distance Vector(AOMDV)routing protocol with a trust model to enhance network *** findings from this research demonstrate the successful fusion of AOMDV with a trust model,resulting in tangible improvements in network *** assessment of trustworthiness bolsters both security and routing capabilities in IoT *** trust model plays a crucial role in mitigating black hole attacks in IoT networks by evaluating the trustworthiness of nodes and helping in the identification and avoidance of malicious nodes that may act as black *** results validate the efficacy of the proposed trust-based routing mechanism in achieving its *** plays a pivotal role in decision-making and in the creation of secure distribution *** assessing the trustworthiness of nodes,both network security and routing efficiency can be *** effectiveness of the proposed trust-based routing mechanism is scrutinized through simulations,offering insights into its potential advantages in terms of improved network security and routing performance in the context of the IoT.

关键词： Mobile ad-hoc network(MANET) routing Ad hoc On-demand Multipath Distance Vector(AOMDV) trust model security

Casting of microstructured shark skin surfaces and possible applications on aluminum casting parts

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China Foundry 2011年第1期8卷 62-65页

作者： Todor Ivanov Andreas bührig-polaczek Uwe Vroomen Foundry Institute of RWTH Aachen University

Within the project "Functional Surfaces via Micro-and Nanoscaled Structures" which is part of the Cluster of Excellence "Integrative Production Technology" established and financed by the German Research Foundation (DFG),an investment casting process to produce 3-dimensional functional surfaces down to a structural size of 1μm on near-net-shape-casting parts has been *** common way to realize functional microstructures on metallic surfaces is to use laser ablation,electro discharge machining or micro *** handicap of these processes is their limited *** approach of this project to raise the efficiency is to use the investment casting process to replicate microstructured surfaces by moulding from a laser-microstructured grand master *** main research objective deals with the investigation of the single process steps of the investment casting process with regard to the moulding *** results concerning making of the wax pattern,suitability of ceramic mould and core materials for casting of an AlSi7Mg0.3 alloy as well as the knock-out behavior of the shells are *** using of the example of an intake manifold of a gasoline race car engine,a technical shark skin surface has been realized to reduce the drag of the intake *** intake manifold consists of an air-restrictor with a defined inner diameter which is microstructured with technical shark skin *** this reason the inner diameter cannot be drilled after casting and demands a very high accuracy of the casting part.A technology for the fabrication and demoulding of accurate microstructured castings are *** factors of different moulding steps of the macroscopic casting part as well as the microscopic riblet structure have been examined as well.

关键词： investment casting microstructured surfaces shark skin

等轴球晶凝固多相体系内热溶质对流、补缩流及晶粒运动的数值模拟 Ⅰ．三相流模型

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金属学报 2006年第6期42卷 584-590页

作者：王同敏姚山张兴国金俊泽 M Wu A Ludwig b Pustal a.bührig-polaczek 大连理工大学材料科学与工程学院三束材料改性国家重点实验室辽宁省原材料特种制备技术重点实验室 Simulation and Modeling of Metallurical Processes University of Leoben Leoben A-8700 Austria Foundry Institute RWTH Aachen University Aachen D-52072 Germany

基于Eulerian-Eulerian方法和体积元平均技术,建立了模拟等轴球晶凝固过程的液、固、气三相流模型．液、固两相处理成相互分离、相互扩散的介质,气相与液、固两相只存在热量及动量的相互作用,三相(凝固前)作为自由流体共享一个统一的压... 详细信息

基于Eulerian-Eulerian方法和体积元平均技术,建立了模拟等轴球晶凝固过程的液、固、气三相流模型．液、固两相处理成相互分离、相互扩散的介质,气相与液、固两相只存在热量及动量的相互作用,三相(凝固前)作为自由流体共享一个统一的压力场．分别求解三相的质量、动量、溶质、热焓守恒方程;相间的热量交换和摩擦拖拽以及液／固界面上的溶质再分配和凝固潜热释放,通过定义对应守恒方程的源项和交换项而加以考虑;另外,单独求解一个晶粒密度守恒方程．晶粒的形核生长(相变) 也加以模型化并体现在对应的源项中,模型中所用的密度定义为溶质与温度的函数,因此可综合考虑热溶质对流、晶粒运动及凝固收缩所引起的补缩流动．凝固过程的体积收缩及补缩流动将体现在气／液自由表面的波动上．

关键词：热溶质对流补缩流晶粒运动三相流数值建模

Transient transport processes in deformable porous media

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Chinese Physics b 2011年第11期20卷 167-175页

作者： Cs.Mészáros a.bálint Szent István University Department of Physics and Process Control Szent István University Department of Chemistry and Biochemistry

The basic partial differential equations relevant for convection-diffusion and convection-diffusion-wave phenomena arc presented and solved analytically by using the MAPLE symbolic computer algebra system. The possible general nonlinear character of the constitutive equation of the convection-discussion process is replaced by a direct posteriori stochastic refinement of its solution represented for Dirichlet-type boundary conditions. A thermodynamic analysis is performed for connecting the relaxation time constants and Jacobi-determinants of deformations at transient transport processes. Finally, a new procedure for general description of coupled transport processes on the basis of the formalism originally developed for convection-free phenomena is presented by matrix analysis methods in the Fourier space.

关键词： convection binary mixtures relaxation time matrix polynomials

black hole shadows in Einstein-bel-Robinson gravity

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Chinese Physics C 2024年第5期48卷 272-283页

作者： b.Hamil b.C.Lütfüoğlu Laboratoire de Physique Mathématique et Subatomique Facultédes Sciences ExactesUniversitéConstantine 1ConstantineAlgeria Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia

Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. Einstein-bel-Robinson (EbR) gravity with quartic curvature modification motivated Sajadi et al. to explore static spherically symmetric black hole solutions using perturbative methods. In this study, inspired by their work, we investigate AdS black hole shadows in EbR gravity and demonstrate how the gravity parameter alters the energy emission rate. Finally, we address the same problem in the presence of plasma, because the black holes are thought to be surrounded by a medium that changes the geodesic of photons.

关键词： black hole shadows Einstein-bel-Robinson gravity plasma