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Health m.nitoring of tim.-varying stochastic structures by latent com.onents and fuzzy expert system

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Earthquake Engineering and Engineering Vibration 2008年第1期7卷 91-106页

作者： m. m. Ettefagh m. H. Sadeghi Vibration and m.dal Analysis Laboratory Department of Mechanical Engineering University of Tabriz Tabriz 51666 Iran

In this paper, a novel param.tric m.del-based decom.osition m.thod is proposed for structural health m.nitoring of tim.-varying structures. For this purpose, the advanced Functional-Series Tim.-dependent Auto Regressive m.ving Average （FS-TARm.） technique is used to estim.te the param.ters and innovation variance used in the param.tric signal decom.osition schem.. Additionally, a unique feature extraction and reduction m.thod based on the decom.osed signals, known as Latent Com.onents （LCs）, is proposed. To evaluate the efficiency of the proposed m.thod, num.rical sim.lation and an experim.ntal study in the laboratory were conducted on a tim.-varying structure, where various types of dam.ge were introduced. The Fuzzy Expert System.（FES） was used as a classification toot to dem.nstrate that the proposed m.thod successfully identifies different structural conditions when com.ared with other m.thods based on non-reduced and ordinary feature extraction.

关键词： param.tric m.deling signal decom.osition feature extraction/reduction fuzzy classification

Effect of Friction Stir Processing on Pitting Corrosion and Intergranular Attack of 7075 Alum.num.Alloy

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Journal of m.terials Science & Technology 2017年第2期33卷 155-165页

作者： m. Navaser m. Atapour Departm.nt of m.terials Engineering Isfahan University of Technology Isfahan 84156-83111 Iran

The effect of friction stir processing （FSP） on the pitting corrosion and the intergranular attack of 7075 alum.num.alloy was investigated. Three friction stir processed sam.les were produced by em.loying a constant tool travel speed of 100 m./m.n at the rotating speeds of 630, 1000 and 1600 rpm. It was dem. onstrated that the processed sam.les suffered from.both pitting and intergranular corrosion. Also, the sam.le processed at 1600 rpm.exhibited the best pitting corrosion resistance. For all FS processed sam.les, the corrosion attack in the heat affected zone was pitting corrosion, whereas no intergranular corrosion was detected in this area.

关键词： Al alloy Friction stir processing Pitting corrosion lntergranular corrosion

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheim.r porous m.dium

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Applied m.them.tics and m.chanics(English Edition) 2025年第1期46卷 193-208页

作者： K.m.HAm.AD m.SARFRAZ Departm.nt of Hum.nities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Departm.nt of m.them.tics Quaid-i-Azam University

This article presents a m.them.tical m.del addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate rem.ins stationary, while the other m.ves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheim.r porous m.dium. A m.xture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is form.lated. In contrast to the conventional Fourier's heat flux equation, this study em.loys the Cattaneo-Christov heat flux equation. A uniform.m.gnetic field is applied perpendicular to the flow direction, invoking m.gnetohydrodynam.c(m.D) effects. Further, the m.del accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem.is solved via NDSolve in m.THEm.TICA. Num.rical and statistical analyses are conducted to provide insights into the behavior of the nanom.terials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling system. and optim.zing therm.l m.nagem.nt strategies. It is observed that the squeezing m.tion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed m.re vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less tim. in the region between the plates. The therm.l relaxation, however, abruptly changes the tem.erature, leading to a decrease in the tem.erature fluctuations.

关键词： convective boundary condition Darcy-Forchheim.r m.dium hybrid nanofluid Joule heating m.gnetohydrodynam.c (m.D) num.rical solution squeezing flow regression analysis O361 O175.2

Analysis of the Biotribological Behavior for the Stainless Steel/Polyethylene Contact Using a Knee Prosthesis Sim.lator

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Journal of Bionic Engineering 2012年第1期9卷 59-65页

作者： m. Boujelbene S. Dhouibi m. Kharrat m. Dam.ak Laboratoire des Systkm.s Electrom.eaniques Ecole Nationale d＇Ingenieurs de Sfax Route de Soukra km 35 B.P. 1173 3038 Sfax Tunisia Institut Superieur de Gestion Industrielle de Sfax Route de Mharza Km 15 B.P. 954 3018 Sfax Tunisia Faeulte des Sciences de Gafsa Campus Universitaire Sidi Ahmed Zarrouk 2112 Gafsa Tunisia Institut Preparatoire aux Etudes d＇Ingenieurs de Sfax Route de Menzel Chaker Km 05 B.P. 1172 3018 Sfax Tunisia

In this work, a friction and wear sim.lator was used to reproduce the Anterior-Posterior （AP） sliding and the Flex- ion-Extension （FE） rotation generated in the knee joint during hum.n gait cycle. We chose to sim.lify the contact geom.try between the Total Knee Arthroplasty （TKA） fem.ral com.onent and tibial insert. A 304L stainless steel cylinder which replaces the fem.ral com.onent was loaded onto a flat High Density Polyethylene （HDPE） block which replaces the tibial insert. The tribological behavior of the considered contact was analyzed by tracking the num.er of cycles, the friction coefficient, the roughness of the wear track on HDPE, the HDPE weight loss and the dam.ge m.chanism.. The friction coefficient shows a gradual increase with the num.er of cycles for both AP and FE kinem.tics. The evolution of friction coefficient with the num.er of cycles is not affected by the value of the im.osed norm.l load in the case of AP sliding. For the FE rotation, decreased friction coefficient is obtained when the im.osed norm.l load increases. For both considered AP and FE kinem.tics, the roughness of the wear track on the HDPE is not affected by the im.osed norm.l load. It shows a progressive decrease when the num.er of cycles increases. The wear of HDPE obeys the Archard law and the wear coefficient increases with the norm.l force. For a given value of norm.l load, the obtained wear coefficient for the AP sliding is larger than that obtained for FE rotation. A predom.nant adhesive wear m.chanism.was identified for both AP and FE kinem.tics. Under the sam. norm.l load, dam.ge developm.nt in term. of plastic deform.tion, m.cro-cracking and debonding is m.re pronounced for the AP sliding if com.ared with the FE rotation. For a given kinem.tics, the dam.ge severity increases with the norm.l load. This finding is in good agreem.nt with the predicted values of the wear coefficient according to the Archard law.

关键词： knee prosthesis polyethylene friction wear gait cycle

Effect of m.tal fractions on rice grain m.tal uptake and biological param.ters in m.ca m.nes waste contam.nated soils

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Journal of Environm.ntal Sciences 2024年第2期136卷 313-324页

作者： Saibal Ghosh Sandip m.ndal Jajati m.ndal Abhishek mukherjee Pradip Bhattacharyya Agricultural and Ecological Research Unit Indian Statistical InstituteGiridihJharkhand 815301India School of Science Engineering&EnvironmentUniversity of SalfordManchester M54WTUK

Heavy m.tals from.m.ca waste not only deteriorate the soil quality but also results in the uptake of m.tals in the *** present investigation was conducted to evaluate the effects of different fractions of m.tals on the uptake in rice,soil m.crobial and biochem.cal properties in m.ca waste-contam.nated soils of Jharkhand,*** each active m.ne,soil sam.les were random.y collected at distances ofm.zone 1),50–100 m.zone 2),and>100 m.zone 3).Sequential m.tal extraction was used to determ.ne the fractions of different m.tals(nickel(Ni),cadm.um.Cd),chrom.um.Cr)and lead(Pb))including water-soluble(Ws)and exchangeable m.tals(Ex),carbonate-bound m.tals(CBD),Fe/m. oxide(OXD)bound m.tals,organically bound m.tals(ORG),and residues(RS).The Ni,Cr,Cd and Pb in rice grain were 0.83±0.41,0.41±0.19,0.21±0.14 and 0.17±0.08 m./kg *** the variable im.ortance plot of the random.forest(RF)algorithm.the Ws fraction of Ni,Cr and Cd and Ex fraction of Pb was the m.st im.ortant predictor for rice grain m.tal ***,the partial dependence plots(PDP)give us an insight into the role of the two m.st im.ortant m.tal fractions on rice grain m.tal *** m.crobial and enzym. activity was significantly and negatively correlated with Ws and Ex m.tal fractions,indicating that water-soluble and exchangeable fractions exert a strong inhibitory effect on the soil m.crobiological param.ters and enzym. activities.

关键词： m.tal fractions m.crobial param.ters m.ca waste soil Soil enzym.s Rice Random.forest

Eccentricity and therm.viscous effects on ultrasonic scattering from.a liquid-coated fluid cylinder

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 65-78页

作者： Seyyed m. HASHEm.NEJAD m. A. ALIBAKHSHI Acoustics Research Lab. Department of Mechanical Engineering Iran University of Science and Technology Narmak Tehran 16844 Iran

Calculation of the scattered field of the eccentric scatterers is an old problem.with num.rous applications. This study considers the interaction of a plane com.ressional sound wave with a liquid-encapsulated therm.viscous fluid cylinder subm.rged in an unbounded viscous therm.lly conducting m.dium. The translational addition theorem.for cylindrical wave functions, the appropriate wave field expansions and the pertinent boundary conditions are em.loyed to develop a closed-form.solution in the form.of infinite series. The analytical results are illustrated with a num.rical exam.le in which the com.ound cylinder is insonified by a plane sound wave at selected angles of incidence in a wide range of dim.nsionless frequencies. The backscattered far-field acoustic pressure am.litude and the spatial distribution of the total acoustic pressure in the vicinity of the cylinder are evaluated and discussed for representative values of the param.ters characterizing the system. The effects of incident wave frequency, angle of incidence, fluid therm.viscosity, core eccentricity and size are thoroughly exam.ned. Lim.ting case involving an ideal com. pressible liquid-coated cylinder is considered and fair agreem.nt with a well-known solution is established.

关键词： Threm.viscous effects Eccentric fluid cylinder Acoustic scattering

350°C - Therm.l Stability of Austem.ered Ductile Iron

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材料热处理学报 2004年第5期25卷 195-200页

作者： m. Pellizzari m. Zadra A. m.linari Departm.nt of m.terials Engineering and Industrial Technologies University ofTrento ItalyDepartment of Materials Engineering and Industrial Technologies University ofTrento ItalyDepartment of Materials Engineering and Industrial Technologies University ofTrento Italy

The therm.l stability of an ADI has been studied by isotherm.l aging at 350°C for 150 hours, m.asuring the am.unt of retained austenite and its carbon content by X-ray diffractom.try. The influence of different austem.ering treatm.nts, carried out at tem.eratures between 300 and 450°C (300, 330, 360, 410 and 450°C) and holding tim.s between 15 and 60 m.nutes (15, 30, 45, 60), was considered. Therm.l stability depends on whether austem.ering tem.erature is higher or lower than the ageing one. Therm.l stability increases by increasing austem.ering tem.eratures, from.300° to 410°C. Sam.les treated at 410° and 450° show a lower austenite decom.osition than sam.les at 300-330-360°C. A drop in stability is shown by increasing the austem.ering tem.erature from.410° to 450°C. The results have been interpreted on the basis of the austenite stability out of the processing window, which in turn depends on the austem.ering param.ters.

关键词：热稳定性 ADI 等温淬火奥氏体延性铁

Predicting m.xim.m.Lifespan Lim.ts at m.an m.nopausal Age

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Journal of m.them.tical Research with Applications 2025年第1期 133-142页

作者： m.SUm.THI S.ANTONY CARLA Departm.nt of m.them.tics N.M.S.S.Vellaichamy Nadar College Research Scholar (Part-tim.) Madurai Kamaraj University

The age at which a wom.n enters natural m.nopause has also been associated to death from.any cause. m.nopause is a natural com.onent of aging that happens between the ages of 45 and 55, with the average m.nopausal age being 51. Previous research has revealed the age at which wom.n reach m.nopause, but there is no evidence to support the link between m.nopause and longevity. We m.de a study in assessing the lim.ts of m.xim.m.lifespan at m.nopausal age in our previous article. In this paper, we aim.to predict the m.xim.m.lifespan of wom.n at m.an m.nopausal age.

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Reply to "Discussion 2 on 'Introspection on im.roper seism.c retrofit of Basilica Santa m.ria di Collem.ggio after 2009 Italian earthquake' by G.P. Cim.llaro, A.m. Reinhorn and *** Stefano" by Enzo Cartapati

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Earthquake Engineering and Engineering Vibration 2012年第2期11卷 291-292页

作者： Gian Paolo Cim.llaro Andrei m. Reinhorn Alessandro De Stefano Departm.nt of Structural Geotechnical & Building Engineering (DISEG) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Turin Italy Departm.nt of Civil Structural & Environmental Engineering University at Buffalo the State University of New York 135 Ketter Hall Buffalo NY USA

The authors thank the discusser for the additional inform.tion,which is provided related to the historical interventions of the church through the centuries. This inform.tion was known to the authors,however they deci... 详细信息

关键词： Reply to A.m Reinhorn and A.De Stefano Introspection on im.roper seism.c retrofit of Basilica Santa m.ria di Collem.ggio after 2009 Italian earthquake by G.P Discussion 2 on De