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Finite Elements modelling and assessment of ceramic rollers with edge cracks

Procedia Structural Integrity 2024年 57卷 236-249页

作者： Yuri Kadin Charlotte Vieillard Jeroen Wensing Anand Theerthan SKF Research & Technology Development Houten The Netherlands

To ensure reliability of hybrid cylindrical roller bearings each ceramic roller is inspected, and scrapped if a surface imperfection above the critical size is detected. This inspection aims to reduce the potential root cause of Rolling Contact Fatigue (RCF) which can occur during operation, shortening the bearing life. The rejection criterion is based on experimental and theoretical knowledge, which for the last decade was developed in SKF for the material imperfections mainly located on the rolling element raceway. These imperfections are subjected to high contact pressure and therefore are considered as the primary root cause of RCF failure. Regarding rollers, however, imperfections can be present beyond the raceway, i.e. at the roller chamfer where the lower risk of RCF is expected, because the edge imperfections are typically out of the rolling contact zone. Nevertheless, the risk associated with these features should be assessed too, chiefly because the size of edge imperfections can be rather large. In our previous study, the imperfection termed as a Missing Material was studied, combining the semi-analytical tool for the contact mechanics and the Finite Elements (FE) method for the stress analysis. In the current work, another imperfection type is considered, and this is a surface crack located at the chamfer of ceramic roller. The RCF analysis is based on the semi-analytical evaluation of the rolling contact pressure (between a ceramic roller and a steel inner ring), and computational fracture mechanics for the estimation of fatigue crack propagation.

关键词： Si3N4 Ceramic rollers Hybrid bearing Fracture mechanics Rolling contact fatigue Finite Elements Material imperfections

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High Torque Capability Non-Permanent Magnet Hybrid Excited Switched Reluctance Motor for Electric Vehicle Application

High Torque Capability Non-Permanent Magnet Hybrid Excited S...

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2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023

作者： Abhijith, Vijina Hossain, M.J. Lei, Gang Sreelekha, Premlal Ajikumar Kadam, Sandeep B University of Technology Sydney School of Electrical and Data Engineering Sydney Australia Entuple e Mobility Research and Development Bangalore India TechEmbers Research and Development Kerala India

ISBN: (纸本)9798350316445

Switched reluctance motors (SRMs) have become more prevalent in electric traction motors because they operate at high speeds, have optimum control, and can improve electrically driven performance with multiple phases overlapping. This can be attributed to their maximum torque per ampere and power density. The design and development of specialized electrical machines, like SRMs, have proliferated in recent years as an alternative to DC series and permanent magnet-based (PM) motors. This paper presents the design consideration and the performance evaluation of a hybrid excited non-permanent magnet assisted switched reluctance motor for electric vehicles (EV) applications. The hybrid excitation of switched reluctance motors (HESRM) is attracting considerable demand in the EV market due to its high torque performance. However, this method is currently incorporated with PM-assisted excitation to enhance the performance of SRMs. This newly designed hybrid excitation method enhances torque performance without using rare earth elements by injecting direct current (DC) through the designated auxiliary poles. The novel machine's static characteristics and dynamic performance are simulated and compared with the conventional SRM drives of the same ratings. Consequently, two motor prototypes are redesigned, and the concept is validated through experimental analysis. In all speed ranges, the proposed topologies provide significantly greater electromagnetic torque than the conventional ones. Because of its fault tolerance, multiple control topologies and redundancy were attained, thus making this machine well-suited for EV applications. © 2023 IEEE.

关键词： electric vehicle hybrid excitation of switched permanent magnet reluctance motor switched reluctance motor

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Leveraging Blockchain for Cloud Log Security and Compliance in AWS

Leveraging Blockchain for Cloud Log Security and Compliance ...

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2025 IEEE International Students' Conference on Electrical, Electronics and Computer Science, SCEECS 2025

作者： Singh, Gursimar Singh, Dhawan Chandigarh University Apex Institute of Technology Mohali India University Centre for Research and Development Chandigarh University Apex Institute of Technology Mohali India

ISBN: (纸本)9798331529833

As the demand for cloud computing is increasing across the globe, more and more companies are shifting their data and IT infrastructure to the cloud. Log data integrity, security, and compliance are important in such an environment for anomaly detection, audit trails, and regulatory adherence. However, traditional log management systems suffer from tampering, data breaches, and centralized control. Recent research has, therefore, looked into blockchain technology as a means of boosting cloud security. This paper presents a blockchain-based approach to securing and authenticating AWS cloud logs. Utilizing the blockchain's immutable and decentralized nature, the proposed system hashes AWS CloudWatch logs with a Python-based system and records the hash on the Ethereum blockchain via a smart contract. This process prevents undetected log alteration or deletion. The smart contract manages log hash storage and verification, with the Infura node facilitating Ethereum blockchain interactions and MetaMask handling private keys and test ETH. Original and modified log hashes are compared to assure the system's efficiency, besides computing transaction costs and processing times. The findings suggest blockchain's potential as a solid framework for log data security and compliance, offering a decentralized, tamper-proof log storage solution that enhances cloud infrastructure security and compliance for organizations. © 2025 IEEE.

关键词： Cloud security

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Geochemical characteristics of produced fluids from CBM wells and their indicative significance for gas accumulation in Daning-Jixian block,Ordos Basin

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Frontiers of Earth Science 2023年第3期17卷 661-678页

作者： Taotao YAN Chao YANG Shuai ZHENG Yadong BAI Wei CHEN Yanfei LIU Wenguang TIAN Shasha SUN Shangwen JIN Jiahang WANG Zhenxing LIU Huifang YAO College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China Coal Reservoir Laboratory of National Engineering Research Center of CBM Development&Utilization China University of GeosciencesBeijing 100083China China Coal Geology Group Co. LtdBeijing 100043China Research Institute of Petroleum Exploration and Development(Northwest) PetroChinaLanzhou 730000China Beijing Furuibao Energy Technology Company Beijing 100176China PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China Engineering Institute of SINOPEC Shanghai Offshore Oil&Gas Company Shanghai 200120China Exploration and Development Research Institute of PetroChina Huabei Oilfield Company PetroChinaRenqiu 062552China

The Daning-Jixian block,the eastern edge of the Ordos Basin,is one of the most potential areas for CO_(2)geological storage,enhanced coalbed methane recovery(ECBM)exploration and production in China in recent *** ionic composition and total dissolved solids(TDS)of the produced water,coal organic matter maturity,molecular composition and carbon isotope characteristics of the produced gas were utilized to analyze the hydrogeological condition,CBM generation and migration characteristics in this *** CBM enrichment patterns and the geological impacts on gas well production characteristics were *** optimal area for CBM development and CO_(2)geological storage in the study area were also *** by the Xueguan reverse fault zone,the hydraulic unit in this area can be divided into two parts(i.e.,the recharge-runoff zone in the east and the weak runoff-stagnation zone in the west).The thermogenic gas is dominating CBM genesis in this *** biogenic gas replenishment is only distributed in the eastern margin area,where theδ13C1 value is less than the thermal simulation results as an influence of hydrodynamic ***,two models of CBM formation and accumulation were proposed,1)thermogenic CBM migrated by hydrodynamic and resorbed for preservation at impermeable fault boundaries;2)thermogenic CBM trapped by fault and accumulated by hydrodynamic in slope *** gas production performance,generally increased from east to west,is mainly dominated by hydrogeological ***,the west side of the fault zone is the enrichment and high-yield area for ECBM development and CO_(2)geological storage in the study area.

关键词： produced water and gas gas accumulation geochemical parameter CBM production CO_(2)geological storage Daning-Jixian block

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Tight sandstone diageneses,evolution,and controls on high-graded reservoirs in slope zones of foreland basins:A case study of the fourth Member of Xujiahe Formation,Tianfu gas field,Sichuan Basin

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China Geology 2025年第2期8卷 325-337页

作者： Zhi-min Jin Ji-rong Xie Zheng-lin Cao Yu-chao Qiu Chao Zheng Liang-biao Lin Yu Yu Exploration and Development Research Institute Exploration and Development Research Institute of Southwest Oil&Gas field CompanyPetroChina Chengdu 610051China Exploration and Development Research Institute of Southwest Oil&Gas field Company PetroChina Chengdu 610051China PetrChina Research Insititute of Petroleum Exploration and Development Beijing 100083China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China Institute of Sedimentary Geology Chengdu University of TechnologyChengdu 610059China

The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent *** fourth member of the Xujiahe Formation(Xu4 Member),the major interval in the Jianyang Block of the Tianfu gas field in the basin,is characterized by considerable buried depth,tight reservoirs,and strong *** using cast thin section,X-ray diffraction(XRD),scanning electron microscopy(SEM),fluid inclusion thermometry,and core analysis,the reservoir rock types,dominant diageneses,diagenetic history,and controls on high-graded reservoirs were *** is found that the Xu4 Member in Jianyang mainly consists of lithic feldspar sandstones and feldspar lithic sandstones,followed by lithic quartz ***-energy hydrodynamic conditions in the microfacies of underwater distributary channels and mouth bars are beneficial to the preservation of primary pores and the occurrence of secondary pores,and there are no significant differences in petrophysical properties between these two *** and calcareous cementation are the dominant controls on reservoir porosity decrease in the Xujiahe Formation;corrosion is the major contributor to porosity increase by generating secondary dissolved pores,*** dissolved pores and intergranular dissolved pores,as major reservoir space in the study *** zones around the faults inside the Xujiahe Formation(fourth‒order faults)are favorable for proximal tight gas accumulation,preservation,and *** research findings have been successfully applied to explore the Xujiahe Formation in the slope zone of the Sichuan foreland *** can be referential for other similar tight sandstone gas accumulations.

关键词： Slope zone of foreland basin Tight sandstone Tight gas Proximal tight gas accumulation High-graded reservoir Xujiahe Formation Jianyang Block Oil-gas exploration engineering Sichuan Basin

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Effect of annealing temperature on the interfacial precipitation layer of the explosive welding of flame-resistant magnesium alloy and aluminum alloy

Keikinzoku Yosetsu/Journal of Light Metal Welding

引用

Keikinzoku Yosetsu/Journal of Light Metal Welding 2023年第8期61卷 362-367页

作者： Mori, Hisashi Mihara-Narita, Mami Asai, Konosuke Saito, Naobumi Chino, Yasumasa Minoda, Tadashi Kato, Katsuya Tanaka, Hiroki Research and Development Center UACJ Corporation Japan Department of Physical Science and Engineering Graduate School of Engineering Nagoya Institute of Technology Japan Japan

The explosive welding material of flame-resistant magnesium alloy (Mg-Al-Zn-Ca alloy: AZX611) and alminium alloy (Al-Mg-Si alloy: A6005C) was annealed at 473 K to 673 K and the characteristics of the intermetallic compound layer formed at the interface were *** the explosive material was annealed, a layered structure was formed at the interface of AZX611/A6005C, and the thickness of layered structure increased with the annealing temperature. The layered structure was an intermetallic compound of Al and Mg, and it was estimated that it corresponded to b-Mg2Al3 when the annealing temperature was 473 K, and b-Mg2Al3＋g-Mg17Al12 when the annealing temperature was 523 K or higher. The growth of the layered structure of the annealed material of the explosive welding clad material of AZX611/A6005C was also considered to be due to diffusion rate-determining. © 2023 Japan Light Metal Welding and Construction Assoc.. All rights reserved.

关键词： Magnesium alloys

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development and Test of 500 kV Repetitive Pulsed Power Source for HPM Application

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IEEE Transactions on Plasma Science 2023年第6期51卷 1459-1465页

作者： Shanmuganathan, U. Saket, K. Das, M.K. Srikrishna, P. Senthilkumar, S. Microwave Tube Research and Development Center Bangaluru560013 India National Institute of Technology Department of Electrical and Electronics Engineering Trichy620015 India

A compact peaking capacitor-based 500 kV, 10 kA, 100 Hz repetition rate pulsed power source has been designed and developed for high-power microwave applications. This system utilizes a 500 kV, 1.9 nF peaking capacitor to deliver the nanosecond pulse with a peak current of 10 kA. An eight-stage bipolar Marx generator (MG) with 35 kV charging voltage is used for driving this peaking capacitor. The design was carried out by an analytical approach and confirmed by simulation for the MG with and without peaking capacitors using PSpice software. The simulated results were compared to study the enhancement of voltage pulse using a peaking capacitor. The system was developed and tested experimentally with and without a peaking capacitor with different load impedances. The experimental results show the merits of peaking capacitor implementation. The system is suitable for driving HPM load at a high repetition rate with less input energy than similar systems. © 1973-2012 IEEE.

关键词： Capacitance

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Structurization of Full Surface Emissive MAPbBr3 Crystals: from Fluorescent Tags to Resonant Nanostructures

Structurization of Full Surface Emissive MAPbBr3 Crystals: f...

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CLEO: Science and Innovations in CLEO 2024, CLEO: S and I 2024 - Part of Conference on Lasers and Electro-Optics

作者： Kowal, Dominik Mahato, Somnath Rola, Krzysztof Czyż, Krzysztof Birowosuto, Muhammad Danang Lukasiewicz Research Network - PORT Polish Center for Technology Development Stablowicka 147 Wroclaw54-066 Poland

MAPbBr3 perovskites are known for bright green surface emission. We utilize the micromachining and nanofabrication tools to alter the photoluminescence properties of this perovskite and create fluorescent patterns and... 详细信息

关键词： Fluorescence

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Impact of dietary lysophospholipids supplementation on growth performance, meat quality, and lipid metabolism in finishing bulls fed diets varying in fatty acid saturation

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Journal of Animal Science and Biotechnology 2025年第2期16卷 831-844页

作者： Meimei Zhang Haixin Bai Ruixue Wang Yufan Zhao Wenzhu Yang Jincheng Liu Yonggen Zhang Peixin Jiao College of Animal Science and Technology Northeast Agricultural UniversityHarbin 150030People’s Republic of China Lethbridge Research and Development Centre Lethbridge T1J 4B1Canada

Background The objective of this study was to evaluate the effects of dietary fatty acids(FA)saturation and lysophospholipids supplementation on growth,meat quality,oxidative stability,FA profiles,and lipid metabolism of finishing beef ***-two Angus bulls(initial body weight:623±22.6 kg;21±0.5 months of age)were *** experiment was a completely randomized block design with a 2×2 factorial arrangement of treatments:2 diets with FA of different degree of unsaturation[high saturated FA diet(HSFA)*** unsaturated FA diet(HUFA)]combined with(0.075%,dry matter basis)and without lysophospholipids *** bulls were fed a high-concentrate diet(forage to concentrate,15:85)for 104 d including a 14-d adaptation period and a 90-d data and sample collection *** No interactions were observed between dietary FA and lysophospholipids supplementation for growth and meat quality parameters.A greater dietary ratio of unsaturated FA(UFA)to saturated FA(SFA)from 1:2 to 1:1 led to lower DM intake and backfat thickness,but did not affect growth performance and other carcass *** with HSFA,bulls fed HUFA had greater shear force in Longissimus thoracis(LT)muscle,but had lower intramuscular fat(IMF)content and SOD content in LT *** with HUFA,feeding the HSFA diet up-regulated expression of ACC,FAS,PPARγ,and SCD1,but down-regulated expression of *** with feeding HSFA,the HUFA diet led to greater concentrations of c9-C18:1 and other monounsaturated FA in LT *** HUFA also led to lower plasma concentrations of cholesterol,but there were no interactions between FA and lysophospholipids *** lysophospholipids improved growth and feed conversion ratio and altered meat quality by increasing muscle pH_(24h),redness values(24 h),IMF content,and concentrations of C18:3,C20:5 and total polyunsaturated fatty ***,lysophospholipids supplementation led to lower malondialdehyde content and up-regulat

关键词： Bulls Fatty acids Lipid metabolism Lysophospholipids Meat quality

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TESTING METHOD FOR WATER ABSORPTION OF STRUCTURAL CONCRETE USING DRILLED HOLE

Journal of Structural and Construction Engineering

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Journal of Structural and Construction Engineering 2023年第806期88卷 558-566页

作者： Nonaka, Akira Yuasa, Noboru Kumagaigumi Technical Research and Development Institute Japan Dept. of Architecture and Architectural Eng. College of Industrial Technology Nihon Univ Japan

The authors have studied Figg’s idea of the drilled hole as an in-situ water absorption testing method. This study aimed to propose an in-situ water absorption testing method for cover concrete up to 50mm from the surface, examining factors affecting the testing results. As a result, the test specifications were determined and the in-situ water absorption assessing method using drilled hole was proposed. The effects of material, mix proportion and curing on the testing results were investigated and the standard deviations of the water absorption data under different water-cement ratios and demolding age were shown. © 2023 Architectural Institute of Japan. All rights reserved.

关键词： Water absorption

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