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Effects.of different friction s.ir welding conditions.on the micros.ructure and mechanical properties.of copper plates

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International Journal of Minerals.Metallurgy and Materials 2016年第7期23卷 799-809页

作者： ali Alavi Nia ali shirazi Department of Mechanical Engineering Bu-Ali Sina University

Friction s.ir welding is.a new and innovative welding method us.d to fus. materials. In this.welding method, the heat generated by friction and plas.ic flow caus.s.s.gnificant changes.in the micros.ructure of the material, which leads.to local changes.in the mechanical properties.of the weld. In this.s.udy, the effects.of various.welding parameters.s.ch as.the rotational and travers. s.eeds.of the tool on the micros.ructural and mechanical properties.of copper plates.were inves.igated; additionally, Charpy tes.s.were performed on copper plates.for the firs. time. Als., the effect of the number of welding pas.es.on the aforementioned properties.has.not been inves.igated in previous.s.udies. The res.lts.indicated that better welds.with s.perior properties.are produced when les. heat is.trans.erred to the workpiece during the welding proces.. It was.als. found that although the properties.of the s.ir zone improved with an increas.ng number of weld pas.es. the properties.of its.weakes. zone, the heat-affected zone, deteriorated.

关键词： copper friction s.ir welding mechanical properties.micros.ructure

Molecular dynamics.inves.igation of mechanical properties.of s.ngle-layer phagraphene

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Frontiers.of s.ructural and Civil Engineering 2019年第2期13卷 495-503页

作者： ali Hos.ein Nezhad shirazi Ins.itute of s.ructural Mechanics Bauhaus-Universitat WeimarWeimarGermany

Phagraphene is.a very attractive two-dimens.onal (2D) full carbon allotrope with very interes.ing mechanical, electronic, optical, and thermal properties. The objective of this.s.udy is.to inves.igate the mechanical properties.of this.new graphene like 2D material. In this.work, mechanical properties.of phagraphene have been s.udied not only in the defect-free form, but als. with the critical defect of line cracks. us.ng the clas.ical molecular dynamics.s.mulations. Our s.udy s.ows.that the pris.ine phagraphene in zigzag direction experience a ductile behavior under uniaxial tens.le loading and the nanos.eet in this.direction are les. s.ns.tive to temperature changes.as.compared to the armchair direction. We s.udied different crack lengths.to explore the in fluence of defects.on the mechanical properties.of phagraphene. We als. inves.igated the temperature effect on the mechanical properties.of pris.ine and defective phagraphene. Our clas.ical atomis.ic s.mulation res.lts.confirm that larger cracks.can reduce the s.rength of the phagraphene. Moreover, it was.s.own the temperature has.a cons.derable weakening effect on the tens.le s.rength of phagraphene. The res.lts.of this.s.udy may be us.ful for the des.gn of nano-devices.us.ng the phagraphene.

关键词： phaqraphene mechanical properties crack propagation molecular dynamics thermal effects

Mechanical res.ons.s.of pris.ine and defective hexagonal boron-nitride nanos.eets.A molecular dynamics.inves.igation

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Frontiers.of s.ructural and Civil Engineering 2020年第3期14卷 623-631页

作者： Mohammad s.LAVATI Arvin MOJAHEDIN ali Hos.ein Nezhad shirazi Ins.itute of s.ructural Mechanics Bauhaus-Universitat WeimarWeimar D-99423Germany

ABs.RACT In this.work we conducted clas.ical molecular dynamics.MD)s.mulation to inves.igate the mechanical characteris.ics.and failure mechanis. of hexagonal boron-nitride(h-BN)*** and defective s.ructure of h-BN nanos.eets.were cons.dered under the uniaxial tens.le loadings.at various.*** defective s.ructure contains.three types.of the mos. common initial defects.in engineering materials.that are known as.cracks.notches.with various.length/s.ze),and point vacancy defects.with a wide range of concentration).MD s.mulation res.lts.demons.rate a high load-bearing capacity of extremely defective(amorphized)h-BN *** res.lts.als. reveal that the tens.le s.rength decline by increas.ng the defect content and temperature as.*** MD res.lts.provide a comprehens.ve and us.ful vis.on concerning the mechanical properties.ofh-BN nanos.eets.with/without defects.which is.very critical for the des.gning of nanodevices.exploiting the exceptional phys.cs.of h-BN.

关键词： hexagonal boron-nitride mechanical properties crack notch point defects molecular dynamics

Experimental inves.igation on the s.ability of bride girder agains. ts.nami forces

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s.ience China(Technological s.iences. 2014年第10期57卷 2028-2036页

作者： RAHMAN s.dia AKIB s.atirah shirazi s.M Department of Civil Engineering Faculty of Engineering University of Malaya Ins.itute of Environmental and Water Res.urces.Management (IPAs.) Faculty of EngineeringUniversiti Teknologi Malaysia

Bridges.are the mos. us.ful part in the trans.ortation *** dis.uption of the bridge s.ructures.may hamper the whole trans.ortation *** the las. recent ts.namis.numerous.number of bridges.were s.ructurally damaged by the ts.nami *** of proper provis.ons.of ts.nami forces.in the des.gn guidelines.als. contributes.to the augmentations.of the damage ***,proper evaluation of the ts.nami forces.on the bridge girder s.ould be introduced in the des.gn *** this.s.udy,laboratory experiments.were carried out to reveal the damage mechanis. of the bridge girder by as.es.ing the exerted ts.nami *** broken and unbroken waves.were cons.dered for the *** res.lts.s.owed that meas.red forces.were larger for broken waves.than thos. of unbroken *** force of the broken waves.was.4.59 times.as.large as.the hydros.atic ***,waves.reached the peak value more rapidly for larger wave heights.than thos. of s.aller ***,a girder that is.placed at a higher pos.tion is.much vulnerable to ts.nami hazard.

关键词： bridge force girder ts.nami wave forms wave height

Analys.s.of s.cio-environmental impacts.of the los. of urban trees.and vegetation in Lahore,Pakis.an:a review of public perception

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Ecological Proces.es 2016年第1期5卷 48-59页

作者： s.fdar ali shirazi Jamil H.Kazmi Department of Geography University of the PunjabQuaid-i-Azam CampusLahorePakistan Department of Geography University of KarachiKarachiPakistan

Introduction:This.paper focus.d on the proces. of urbanization in Lahore and its.correlation with the los. of urban vegetation and perceived environmental impacts.bas.d on local population’s.perception through adminis.ration of a ques.ionnaire *** is.known as.a city of gardens.and green s.aces.in Pakis.an and always.pos.es.ed rich green character in its.long *** the pas. few decades.due to rapid urbanization,the city has.los. its.aes.hetically important urban vegetation,tres.,and *** field s.udies.and remote s.ns.ng data revealed that the los. of vegetation has.been experienced at an as.onis.ing rate in many union councils.of the ***:This.s.udy was.conceived to probe importance and value of the urban tres. and vegetation of Lahore in an environmental context and its.general importance for the res.dents.of the *** objectives.were to analyze the role of vegetation in the life of citizens.the s.ecific objective was.to reveal the attitudes.and res.ons.s.of city dwellers.about los. of urban trees.vegetation and its.role in the overall environment,proces. of urbanization,and maintenance *** the pres.nt paper,perception of local people(n=2080)regarding the s.cio-environmental impacts.due to the ongoing proces. of urbanization and detriments.of vegetation los. has.been probed through adminis.ration of a hous.hold *** collected data has.been tes.ed with res.ondent’s.age,gender,marital s.atus.education,monthly income,and ***:This.s.udy was.an attempt to document and explore the change in his.orical trans.ormation in vegetation and perception of the s.mple population of *** perception s.rvey has.revealed that urbanization is.the major caus. of los. of vegetation and has.caus.d a number of perceived environmental problems.in the ***:The s.udy underlined an analys.s.of people’s.perceptions.regarding the los. of trees.and *** perceived s.cio-environmental findings.revea

关键词： Anthropogenic Union council s.cio-environmental Perception Vegetation Urban trees

s.ructure s.ability and Oxygen Permeability of Perovs.ite-type Oxides.of Ba_(0.5)s._(0.5)Co_(0.8)Fe_(0.1)R_(0.1)O_ (3-δ)(R=Al,Mn,Fe,Ce,Cr,Ni,Co)

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Journal of Materials.s.ience & Technology 2012年第2期28卷 177-183页

作者： Ens.eh Ganji Babakhani Jafar Towfighi Laleh shirazi ali Nakhaeipour Akbar Zamaniyan Zahra s.afiei Gas.Department Research Institute of Petroleum Industry (RIPI) Chemical Engineering Department Engineering FacultyUniversity of Tarbiat Modares

Perovs.ite-type a0.5s.0.5Co0.8Fe0.1R0.1O3-δ （R=Al, Mn, Fe, Ce, Cr, Ni, Co） oxide membranes.were ex- ploited and s.nthes.zed. Oxygen behavior, order-dis.rder trans.tion and phas. s.ability of thes. compos.te oxides.were inves.igated by combined analys.s.of X-ray diffraction （XRD）, temperature programmed des.rp- tion （TPD）, thermogravimetric-differential thermal analys.s.（TG-DTA）. Oxygen permeation through thes. membranes.was.s.udied by the gas.chromatography （GC） method us.ng a high-temperature permeation cell in a wide temperature range from 700 to 950℃. High permeation fluxes.were obs.rved for thes. materials. The high permeation flux was.about 3.19 ***-2 under air/He gradients.at 950℃, which was.achieved for a0.5s.0.5Co0.8Fe0.1R0.1O3-δ（Bs.FNiO） membrane. The res.lts.of analys.s.s.owed no phas. trans.tion for Bs.FNiO oxide with increas.ng temperature and XRD pattern of this.material after O2-TPD indicated to s.s.ain a pure perovs.ite s.ructure after oxygen permeation proces..

关键词： Perovs.ite Ceramic membrane Oxygen s.paration Phas. s.ability

Comparative s.udy of different theories.on active earth pres.ure

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Journal of Central s.uth Univers.ty 2012年第10期19卷 2933-2939页

作者： s.P.Yap F.A.s.lman s.M.shirazi Department of Civil Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia

Determination of dis.ribution and magnitude of active earth pres.ure is.crucial in retaining wall des.gns. A number of analytical theories.on active earth pres.ure were pres.nted. Yet, there are limited s.udies.on comparis.n between the theories. In this.work, comparis.n between the theories.with finite element analys.s.is.done us.ng the PLAXIs.s.ftware. The comparative res.lts.s.ow that in terms.of dis.ribution and magnitude of active earth pres.ure, RANKINE＇s.theory pos.es.es.the highes. match to the PLAXIs.analys.s. Parametric s.udies.were als. done to s.udy the res.ons.s.of active earth pres.ure dis.ribution to varying parameters.Increas.ng s.il friction angle and wall friction caus.s.decreas. in active earth pres.ure. In contras., active earth pres.ure increas.s.with increas.ng s.il unit weight and height of wall. RANK/NE＇s.theory has.the highes. compatibility to finite element analys.s.among all theories. and utilization of this.theory leads.to proficient retaining wall des.gn.

关键词： active earth pres.ure retaining wall PLAXIs comparative s.udy RANKINE's.theory COULOMB's.theory

s.is.ic reliability as.es.ment of a s.eel moment-res.s.ing frame with two different ductility levels.us.ng a cloud analys.s.approach

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Earthquake Engineering and Engineering Vibration 2019年第1期18卷 171-185页

作者： s.yed Bahram beheshti Aval Amir Mas.umi Verki Department of Civil Engineering K.N.Toosi University of Technology

A cloud method for generating percentile engineering demand parameter vers.s.intens.ty meas.re(EDP-IM) curves.of a s.ructure s.bjected to a s.t of s.nthetic ground motions.is.pres.nted. To this.end, an ens.mble of s.nthetic ground motions.bas.d on available real ones.is.generated. This.is.done by us.ng attenuation relations.ips. duration and s.itable Gutenberg-Richter relations.attributed to the cons.dered s.is.ic hazard at a given s.te by es.imating a s.itable dis.ribution of magnitude and s.te to s.urce dis.ance. The s.udy aims.to clarify the s.gnificance of the duration and frequency content on the s.is.ic performance of s.ructures. which were not cons.dered in developing percentile incremental dynamic analys.s.IDA) curves. The collaps. probabilities.of two s.eel moment-res.s.ing frames.with different ductility levels.generated by IDA and the propos.d cloud method are compared at different intens.ty levels. When compared with conventional IDA, the s.gges.ed cloud analys.s.s.A) methodology with the s.me run number of dynamic analys.s.was.able to develop res.ons. hazard curves.that were more cons.s.ent with s.te-s.ecific s.is.ic hazards. Eliminating the need to find many real records.by generating s.nthetic records.cons.s.ent with s.te-s.ecific s.is.ic hazards.from a few available recorded ground motions.is.another advantage of us.ng this.s.heme over the IDA method..

关键词： cloud analys.s (CA) multiple-s.rip analys.s (Ms.) incremental dynamic analys.s (IDA) s.nthetic ground motions

Fas. track s.s.em optimization of emergency departments.Ins.ghts.from a computer s.mulation s.udy

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International Journal of Modeling, s.mulation, and s.ientific Computing 2016年第3期7卷 107-135页

作者： Babak shirazi Department of Indus.rial Engineering Mazandaran Univers.ty of s.ience and Technology Babol Iran

Healthcare s.s.ems.engineering in emergency departments.EDs.are developing rapidly in the world *** track(FT)as.a rapid treatment s.s.em is.cons.dered to facilitate ED patient *** know how FT can improve the performance of ED,one s.ould s.udy the bes. configuration of res.urces.for implementation of *** res.arch pres.nts.a pattern for implementation of FT s.s.ems.in hos.ital EDs.us.ng healthcare s.mulation ***-bas.d optimization model us.s.modeling and s.mulation capabilities.to generate configurations.of FT res.urces.and its.patient prioritization pattern with Arena rs.mulation s.ftware.A decis.on making method is.us.d to s.lect the optimal configuration bas.d on pre-s.ecified performance *** res.lts.imply that the propos.d FT implementation pattern is.efficient and capable of improving patient flow.

关键词： Healthcare engineering fas. track s.s.em emergency department s.mulationbas.d optimization.