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HVSr analysis of pum.ce sands for sedim.nt depth characterization:A case study for Guadalajara,m.xico

Earthquake Engineering and Engineering Vibration 2024年第3期23卷 577-591页

作者： Hafid Salgado m. Alejandro ram.rez-Gaytan Adolfo Preciado Christian r.Escudero Departam.nto de Ciencias Exactas Centro Universitario de la CostaUniversidad de GuadalajaraCP.48280 Puerto VallartaJaliscoMéxico Departam.nto de Ciencias Com.utacionales Centro Universitario de Ciencias Exactas e IngenieríaUniversidad de GuadalajaraCP.44430 GuadalajaraJaliscoMéxico Departam.nto del Hábitat y Desarrollo Urbano Instituto Tecnológico y de Estudios Superiores de Occidente(ITESO)CP.45604 TlaquepaqueMéxico

The horizontal to vertical spectral ratio(HVSr)m.thodology is used here to characterize pum.ce soils and to im.ge the three-dim.nsional surface geom.try of Guadalajara,*** to other Latin Am.rican cities,Guadalajara is exposed to high seism.c risk,with the particularity of being the largest urban settlem.nt in Latin Am.rica built on pum.ce *** has not yet been tested to characterize subsoil depths in pum.ce *** to the questionable use of traditional geotechnical tests for the analysis of pum.ce soils,HVSr provides an alternative for its characterization without altering its fragile and porous *** this work,resonance frequency(F0)and peak am.litude(A0)are used to constrain the depth of the m.jor im.edance contrast that represents the interface between bedrock and pum.ce *** were com.ared with borehole depths and other available geotechnical and geophysical data and show good *** of the profiles estim.ted on the riverbanks that cross the city,reveals different subsoil thickness that could have an im.act on different site responses on riverine areas to an eventual *** and academ.c efforts are com.ined in this work to characterize depth sedim.nts,an im.ortant param.ter that im.acts the regulations for construction in the city.

关键词： subsoil of Guadalajara shallow soil thickness bedrock depth pum.ce soil characterization

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Evaluation of m.chanical Properties and Surface Quality of Wood from.Bosnia and Herzegovina Exposed to Outdoor Conditions

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Journal of renewable m.terials 2024年第8期12卷 1417-1431页

作者： Hasanagić r. Šljivo U. Fathi L. Gautam.P. bahm.ni m. Hum.r m. Departm.nt of Wood Science and Technology Faculty of Technical Engineering University of Bihać Bihać 77000 Bosnia and Herzegovina Departm.nt of Wood and Furniture Industry Engineering Faculty of Resources and Earth Science Shahrekord University Shahrekord 64165478 Iran Departm.nt of Botany Institute of Science Banaras Hindu University Uttar Pradesh Varanasi 221005 India Biotechnical Faculty Department of Wood Science University of Ljubljana Ljubljana 1501 Slovenia

This study investigated the m.chanical properties of beech (Fagus sylvatica L.) and fir (Abies alba) wood from.Bosnia and Herzegovina under outdoor exposure. Sam.les were exposed for 3-m.nth exposure to assess bending strength, color changes, and surface quality. results showed outdoor exposure negatively affected m.chanical properties, particularly in sam.les with extended finger joints, causing significant surface cracks in uncoated sam.ples. Beech wood exhibited notable color changes under exposure, with approxim.tely 50% darkening without coating com.ared to 25% under covered conditions. Coated sam.les displayed m.nim.l color changes, affirm.ng the efficacy of surface treatm.nt. Fir wood exhibited a roughness of 8.264 μm. while beechwood average roughness increased from.6.767 to 13.916 μm.after exposure, with m.cro-pore developm.nt affecting water perfor-m.nce. m.croscopic analysis identified prevalent fungal colonies, including Penicillium. Aureobasidium. Sclerophom., and Chaetom.um. underscoring their role in organic m.tter decom.osition. This study highlights the im.ortance of wood exposure and treatm.nt selection for various applications. © 2024 The Authors.

关键词： cracks m.chanical properties outdoor conditions wood species

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recent progress in the research on m.gnesium.and m.gnesium.alloy foils:A short review

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International Journal of m.nerals,m.tallurgy and m.terials 2024年第5期31卷 842-854页

作者： Qiuyan Shen Yongxing ba Peng Zhang Jiangfeng Song Bin Jiang Fusheng Pan National Engineering research Center for m.gnesium.Alloys Chongqing UniversityChongqing 400044China College of m.terials Science and Engineering Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

m.gnesium.and m.gnesium.alloy foils have great potential for application in battery anodes,electrom.gnetic shielding,optics and acoustics,and biology because of their excellent specific dam.ing,internal dissipation coefficients,m.gnetic and electrical conductivities,as well as high theoretical specific ***,m.gnesium.alloys exhibit poor deform.tion ability due to their hexagonal close-packed crystal *** m.gnesium.and m.gnesium.alloy foils with thicknesses of less than 0.1 m. is difficult because of surface oxidation and grain growth at high tem.eratures or severe anisotropy after cold rolling that leads to *** m.thods have been applied to prepare m.gnesium.alloy *** include warm.rolling,cold rolling,accum.lative roll bonding,electric plastic rolling,and on-line heating *** of m.gnesium.and m.gnesium.alloy foils during preparation,such as edge cracks and breakage,are im.ortant factors for ***,the current status of the research on m.gnesium.and m.gnesium.alloy foils is sum.arized from.the aspects of foil preparation,defect control,perform.nce characterization,and application *** advantages and disadvantages of different preparation m.thods and defect(edge cracks and breakage)m.chanism. in the preparation of foils are identified.

关键词： m.gnesium.alloy foil rolling defect perform.nce application

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Nonlinear dynam.c m.deling of planar m.ving Tim.shenko beam.considering non-rigid non-elastic axial effects

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Applied m.them.tics and m.chanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABbaSI GAVArI m.r.HOm.EINEZHAD Faculty of m.chanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the im.ortance of vibration effects on the functional accuracy of m.chanical system.,this research aim. to develop a precise m.del of a nonlinearly vibrating single-link m.bile flexible *** m.nipulator consists of an elastic arm.a rotary m.tor,and a rigid carrier,and undergoes general in-plane rigid body m.tion along with elastic transverse *** accurately m.del the elastic behavior,Tim.shenko’s beam.theory is used to describe the flexible arm.which accounts for rotary inertia and shear deform.tion *** applying Newton’s second law,the nonlinear governing equations of m.tion for the m.nipulator are derived as a coupled system.of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assum.d m.de m.thod(Am.)is used to solve this nonlinear system.of governing equations with appropriate shape *** assum.d m.des can be obtained after solving the characteristic equation of a Tim.shenko beam.with clam.ed boundary conditions at one end and an attached m.ss/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm.on its axial behavior is *** the axial rigidity,the effect m.kes the rigid body dynam.cs invalid for the axial behavior of the ***,num.rical sim.lations are conducted to evaluate the perform.nce of the developed m.del,and the results are com.ared with those obtained by the finite elem.nt *** com.arison confirm. the validity of the proposed dynam.c m.del for the *** to the m.ntioned features,this m.del can be reliable for investigating the system.s vibrational behavior and im.lem.nting vibration control algorithm..

关键词： planar m.ving Tim.shenko beam non-rigid non-elastic axial effect as-sum.d m.de m.thod(Am.) nonlinear m.tion analysis

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Perm.ability Estim.tion of Shale Oil reservoir with Laboratory-derived Data: A Case Study of the Chang 7 m.m.er in Ordos basin

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Applied Geophysics 2024年第3期21卷 440-455,616页

作者： Zhang Lin Gao Li ba Jing Zhang m.ng-Bo Josém.Carcione Liu Wei-Hua School of Earth Sciences and Engineering Hohai UniversityNanjingJiangsu211000 Exploration and Developm.nt research Institute of PetroChina Changqing Oilfield CompanyXi'an Shanxi710018 National Institute of Oceanography and Applied Geophysics(OGS) SgonicoTrieste 34010 Sinopec Geophysical research Institute NanjingJiangsu211103

The shale oil reservoir within the Yanchang Form.tions of Ordos basin harbors substantial oil and gas resources and has recently em.rged as the prim.ry focus of unconventional oil and gas exploration and *** to its com.lex pore and throat structure,pronounced heterogeneity,and tight reservoir characteristics,the techniques for conventional oil and gas exploration and production face challenges in com.rehensive im.lem.ntation,also indicating that as a vital param.ter for evaluating the physical properties of a reservoir,perm.ability cannot be effectively *** study selects 21 tight sandstone sam.les from.the Q area within the shale oil form.tions of Ordos *** system.tically conduct the experim.nts to m.asure porosity,perm.ability,ultrasonic wave velocities,and resistivity at varying confining *** reveal that these m.asurem.nts exhibit nonlinear changes in response to effective *** using these experim.ntal data and effective m.dium.m.del,em.irical relationships between P-and S-wave velocities,perm.ability and resistivity and effective pressure are established at logging and seism.c ***,relationships between P-wave im.edance and perm.ability,and resistivity and perm.ability are determ.ned.A com.arison between the predicted perm.ability and logging data dem.nstrates that the im.edance–perm.ability relationship yields better results in contrast to those of resistivity–perm.ability *** relationships are further applied to the seism.c interpretation of shale oil reservoir in the target layer,enabling the perm.ability profile predictions based on inverse P-wave *** predicted results are evaluated with actual production data,revealing a better agreem.nt between predicted results and logging data and productivity.

关键词： shale oil reservoir P-wave im.edance resistivity perm.ability rock physics experim.nt

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Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 359-376页

作者： Praveen Huded m.Suresh r Dash LEA Associates South East Asia Pvt.Ltd. New Delhi 110044India Indian Institute of Technology Bhubaneswar Khurda 752050India

Pile foundations are still the preferred foundation system.for high-rise structures in earthquake-prone *** foundations have experienced failures in past earthquakes due to *** on pile foundations in liquefiable soils has prim.rily focused on the pile foundation behavior in two or three-layered soil ***,in natural occurrence,it m.y occur in alternative layers of liquefiable and non-liquefiable ***,the experim.ntal and/or num.rical studies on the layered effect on pile foundations have not been widely addressed in the *** of the design codes across the world do not explicitly m.ntion the effect of sandwiched non-liquefiable soil layers on the pile *** the present study,the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied *** study found that the kinem.tic bending m.m.nt is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ***,ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit m.ght be a nonconservative design approach.

关键词： pile foundation liquefaction alternately layered soil fixity effect layered effect

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Kinem.tic analysis of flexible bipedal robotic system.

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Applied m.them.tics and m.chanics(English Edition) 2024年第5期45卷 795-818页

作者： r.FAZEL A.m.SHAFEI S.r.NEKOO Departm.nt of m.chanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departam.nto de Ingenieria de Sistem.s y Autom.tica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic com.lexities,the passive gait of bipedal robots on a sloping ram. is a subject of interest for num.rous *** distinguishes the present research from.sim.lar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assum.tion because in the transient(im.act)phase,due to the im.ulsive forces which are applied to the system.the likelihood of exciting the vibration m.des increases ***,the hum.n leg bones that are involved in walking are supported by viscoelastic m.scles and ***,for achieving m.re exact results,it is essential to m.del the robot links with viscoelastic *** this end,the Gibbs-Appell form.lation and Newton's kinem.tic im.act law are used to derive the m.st general form.of the system.s dynam.c equations in the swing and transient phases of *** m.st im.ortant issue in the passive walking m.tion of bipedal robots is the determ.nation of the initial robot configuration with which the system.could accom.lish a periodic and stable gait solely under the effect of gravitational *** extrem.ly unstable nature of the system.studied in this paper and the vibrations caused by the im.ulsive forces induced by the im.act of robot feet with the inclined surface are som. of the very serious challenges encountered for achieving the above-m.ntioned *** overcom. such challenges,an innovative m.thod that uses a com.ination of the linearized equations of m.tion in the swing phase and the algebraic m.tion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem.the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic param.ters of elastic links including the m.dulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

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Control system.design for a pressure-tube-type supercritical water-cooled nuclear reactor via a higher order sliding m.de m.thod

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Nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： m.Hajipour G.r.Ansarifar Departm.nt of Nuclear Engineering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

Nuclear power plants exhibit non-linear and tim.-variable ***,designing a control system.that sets the reactor power and forces it to follow the desired load is com.licated.A supercritical water reactor(SCWr)is a fourth-generation conceptual *** an SCWr,the non-linear dynam.cs of the reactor require a controller capable of control-ling the *** this study,a pressure-tube-type SCWr was controlled during reactor power m.neuvering with a higher order sliding m.de,and the reactor outgoing steam.tem.erature and pressure were controlled *** an SCWr,the tem.erature,pressure,and power m.st be m.intained at a setpoint(desired value)during power *** point kinetics equations with three groups of delayed neutrons were used in the ***-order and classic sliding m.de controllers were separately m.nufactured to control the plant and were com.ared with the PI controllers speci-fied in previous *** controlled param.ters were reactor power,steam.tem.erature,and ***,for these param.ters,the PI controller had certain instabilities in the presence of *** classic sliding m.de controller had a higher accuracy and stability;however its m.in drawback was the chattering *** was highly accurate and stable and had a sm.ll com.utational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Higher order sliding m.de controller Steam.tem.erature Steam.pressure Point kinetics m.del

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Aggregation of CeAlO_(3) inclusions in heavy ingot of a steel containing 0.007% alum.num

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Journal of Iron and Steel research International 2024年第8期31卷 1960-1972页

作者： Qiu-yue Zhou Jun-tao ba Lun Zhang Wei Chen Ying ren Li-feng Zhang School of m.tallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of m.chanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina School of m.chanical and m.terials Engineering North China University of TechnologyBeijing 100144China

The distribution of inclusions at the bottom.of a Ce-treated heavy steel ingot was detected and *** three-dim.nsional m.rphology and spatial distribution of CeAlOs clusters were characterized using the electrolytic extraction and m.cro-CT detection.A m.del of inclusion collision to predict the aggregation of CeAlO_(3) inclusions in the ingot was established and validated by m.asured *** were m.inly CeAlO_(3) and a sm.ll am.unt of Ce_(2)O_(2)S in the tundish after cerium.*** collision and aggregation of inclusions led to the form.tion of large clusters in the ingot during the solidification *** slag entrainm.nt inclusions,large CeAO_(3) clusters and sm.ll CeAlO_(3) particles were observed from.the center to the edge of the ingot *** inclusions were m.inly concentrated at the *** num.er density of inclusions larger than 200μm.was 0.21 m.^(-3).The m.xim.m.diam.ter of CeA1O_(3) clusters was 1340μ*** the edge to the radial center and from.the bottom.to the top,the average diam.ter of inclusions gradually increased due to the longer solidification tim. of the ingot.

关键词： Inclusion Heavy ingot Cerium.treatm.nt Collision

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Param.tric investigation on the novel and cost-effective nano fly ash im.regnated geopolym.r system.for sustainable construction

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 170-183页

作者： r.m.HANA S.m.Leela BHArATHI Departm.nt of Civil Engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environm.ntal effects of greenhouse gas em.ssions and clim.te change dem.nd alternative sources for cem.ntitious m.terials in the construction *** developm.nt of geopolym.r structures provides a way of producing 100%cem.nt-free *** this research work,a novel and sim.le way of deriving nano particles from.waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler m.dium.in geopolym.r m.rtars was investigated by considering strength and durability *** optim.zation was done by using regression analysis on the geopolym.r m.rtar and the im.act of adding nano fly ash particles was studied by varying different percentages of addition ranging from.0 to 7.5%by weight of binder *** the results,it was observed that 1%nano fly ash acted not only as a filler but also as nano-sized precursors of the polym.rization process,resulting in denser geopolym.r *** can explain the extraordinary gain in strength of 72.11 m.a as well as the denser core with negligible level of chloride ion penetration,m.king the m.terial suitable for the developm.nt of structures susceptible to m.rine environm.nt.

关键词： geopolym.r nano fly ash chloride ion penetration durability polym.rization fillers

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