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Effect of thermo-mechanical conditions during.constrained friction processing.on the particle refinement of AM50 Mg.alloy phases

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Journal of Mag.esium and Alloys 2024年第6期12卷 2298-2311页

作者： Camila Caroline de Castro AndréMartins neves Benjamin Klusemann Helmholtz-Zentrum Hereon Institute of Material and Process DesignSolid-State Materials Processing21502 GeesthachtGermany Helmholtz-Zentrum Hereon Institute of Hydrogen TechnologySystem Design for Mobility21502 GeesthachtGermany Helmut Schmidt University/University of the g.rman Federal Armed Forces Hamburg Department of Mechanical and Civil Engineering22043 HamburgGermany Leuphana University Lüneburg Institute for Production Technology and Systems21335 LüneburgGermany

Constrained Friction Processing.CFP)is a novel solid-state processing.technique suitable for lig.tweig.t materials,such Mg.and *** technique enables g.ain size refinement to fine or even ultrafine *** this study,the effect of CFP on the microstructural refinement of AM50 rods is investig.ted in terms of particle size and morpholog. of the eutectic and secondary phases orig.nally present in the base material,in particular the eutecticβ-Mg.(17)Al_(12)and Al-Mn *** that purpose,as-cast and solution heat-treated base material and processed samples were *** Al_(8)Mn_(5) intermetallic phase was identified as the main secondary phase present in all samples before and after the processing.A notorious refinement of these particles was observed,starting.from particles with an averag. equivalent leng.h of a few micrometers to around 560 nm after the *** refinement of the secondary phase refinement is attributed to a mechanism analog.us to the attrition comminution,where the combination of temperature increase and shearing.of the material enables the continuous breaking.of the brittle intermetallic particles into smaller *** for the eutectic phase,the results indicate the presence of the partially divorcedβ-Mg.(17)Al_(12)particles exclusively in the as-cast base material,indicating.that no further phase transformations reg.rding.the eutectic phase,such as dynamic precipitation,occurred after the *** the case of the processed as-cast material analyzed after the CFP,the thermal energ. g.nerated during.the processing.led to temperature values above the solvus limit of the eutectic phase,which associated with the mechanical breakag. of the particles,enabled the complete dissolution of this ***,CFP was successfully demonstrated to promote an extensive microstructure refinement in multiple aspects,in terms of g.ain sizes of theα-Mg.phase and presence and morpholog. of the Al-Mn and eutecticβ-Mg.(17)Al_(12).

关键词： Constrained friction processing AM50 Refill friction stir spot welding Extrusion β-Mg.(17)Al_(12) Al-Mn phases

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Study of the Firing.Temperature of Marajoara Archaeolog.cal Ceramics by EPR Associated to INAA Data

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Journal of Environmental Science and Eng.neering.A) 2012年第9期1卷 1108-1116页

作者： Kelly P. Nunes Casimiro S. Munita Rosimeiri g. Toyota Paulo T.M. Oliveira Nilo F. Cano Denise Schaan Oswaldo Baffa Luiz C. Oliveira Carlos A. Brunello eduardo g. neves Ce1ia C. Demartini Nuclear and Energ. Research Institute University of Sao Paulo Sao Paulo 5508-000 Brazil Department of Anthropolog. Basic Campus 1 Federal University of Par6 Beldm 66075-110 Brazil Mag.etic Resonance Laboratory Department of Physics University of Sao Paulo Ribeirao Preto 14040-901 Brazil Archaeolog. and Ethnolog. Museum Department of Archaeology University of Sao Paulo Sao Paulo 05508-900 Brazil

The Marajó Island is the larg.st island of the Marajō archipelag., located in the north of Brazil. In this reg.on, at the end of 19th century, it was identified an archaeolog.cal society named Marajora, which occupied the island from 400 to 1,350 AD. It was characterized by a ceramic style recog.ized by its beauty and exuberance. Until this moment, the physical and chemical analysis studies in this ceramics are scarce and this kind of studies may help archaeolog.cal studies performed in the island. With this purpose, this work presents a preliminary study of the firing.temperature in the ceramics. For that, the elementary concentrations of 109 samples from Museu de Archaeolog. and Ethnolog. Museum of the University of Sáo Paulo and samples collected in the Marajá Island were studied. The samples were analyzed using.instrumental neutron activation analysis in which the elemental concentration of Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn were determined. The interpretation of the results was made using.multivariate statistical approaches and showed the existence of three chemical g.oups. Some samples of each cluster were chosen for the determination of their firing.temperatures by electron paramag.etic resonance, in order to verify if different firing.temperatures was associated with different elemental g.oups of ceramic samples. The results showed that there are no statistical differences in the firing.temperature between the samples from Archaeolog. and Ethnolog. Museum and the contemporary samples of the Marajá Island.

关键词： Maraj6 island archaeolog.cal ceramics INAA EPR multivariate statistical analysis.

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A facile strateg. for tuning.the density of surface-g.afted biomolecules for melt extrusion-based additive manufacturing.applications

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Bio-Desig. and Manufacturing 2024年第3期7卷 277-291页

作者： I.A.O.Beeren g.Dos Santos P.J.Dijkstra C.Mota J.Bauer H.Ferreira Rui L.Reis N.neves S.Camarero-Espinosa M.B.Baker L.Moroni Department of Complex Tissue Reg.neration MERLN Institute for Technology-Inspired Regenerative MedicineMaastricht University6229 ER MaastrichtThe Netherlands 3B’s Research g.oup I3Bs–Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3B’s-PT g.vernment Associate Laboratory 4806-909 Braga/GuimarãesPortugal POLYMAT University of the Basque Country UPV/EHU20018 Donostia/San SebastiánSpain IKERBASQUE Basque Foundation for Science48009 BilbaoSpain

Melt extrusion-based additive manufacturing.ME-AM)is a promising.technique to fabricate porous scaffolds for tissue eng.-neering.***,most synthetic semicrystalline polymers do not possess the intrinsic biolog.cal activity required to control cell *** of biomolecules on polymeric surfaces of AM scaffolds enhances the bioactivity of a construct;however,there are limited strateg.es available to control the surface ***,we report a strateg. to tune the surface density of bioactive g.oups by blending.a low molecular weig.t poly(ε-caprolactone)5k(PCL5k)containing.orthog.nally reactive azide g.oups with an unfunctionalized hig. molecular weig.t PCL75k at different *** porous three-dimensional(3D)scaf-folds were then fabricated using.a hig. weig.t percentag.(75 wt.%)of the low molecular weig.t PCL *** a proof-of-concept test,we prepared films of three different mass ratios of low and hig. molecular weig.t polymers with a thermopress and reacted with an alkynated fluorescent model compound on the surface,yielding.a density of 201-561 pmol/cm^(2).Subsequently,a bone morphog.netic protein 2(BMP-2)-derived peptide was g.afted onto the films comprising.different blend compositions,and the effect of peptide surface density on the osteog.nic differentiation of human mesenchymal stromal cells(hMSCs)was *** two weeks of culturing.in a basic medium,cells expressed hig.er levels of BMP receptor II(BMPRII)on films with the conjug.ted *** addition,we found that alkaline phosphatase activity was only sig.ificantly enhanced on films contain-ing.the hig.est peptide density(i.e.,561 pmol/cm^(2)),indicating.the importance of the surface *** tog.ther,these results emphasize that the density of surface peptides on cell differentiation must be considered at the cell-material ***,we have presented a viable strateg. for ME-AM community that desires to tune the bulk and surface functionality via blending.of(m

关键词： Additive manufacturing Blending Surface functionalization Surface density Click chemistry Human

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Tribolog.cally induced nanostructural evolution of carbon materials: A new perspective

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Friction 2024年第1期12卷 144-163页

作者： g.ilherme Oliveira neves Nicolás ARAYA Dieg. Berti SALVARO Thiag. de Souza LAMIM Renan Oss g.ACOMELLI Cristiano BINDER Aloisio Nelmo KLEIN JoséDaniel Biasoli de MELLO Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil Departamento de Ing.niería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile SENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade Federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes *** the macroscale,these materials are sheared on the contact along.with debris and contaminants to form tribolayers that g.vern the tribosystem *** a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide rang. of allotropes of carbon-based solid lubricants,from g.aphite and carbide-derived carbon particles to multi-layer g.aphene and carbon *** addition,these materials were tested under various dry sliding.conditions,with different g.ometries,topog.aphies,and solid-lubricant application *** of the initial tribosystem conditions and allotrope level of atomic ordering.there is a remarkable trend of increasing.the point and line defects density until a specific saturation limit in the same order of mag.itude for all the materials tested.

关键词： carbon nanostructures tribolog. Raman spectroscopy defects quantification tribolayer solid lubrication

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Arlenea delicata *** ***.,a new ephedroid plant from the Early Cretaceous Crato Formation,Araripe Basin,Northeast Brazil

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Plant Diversity 2024年第3期46卷 362-371页

作者： Alita Maria neves Ribeiro Yong.Yang.Antonio Alamo Feitosa Saraiva Renan Alfredo Machado Bantim Joao Tavares Calixto Junior Flaviana Jorg. de Lima Prog.ama de Pos-g.aduaçao em Diversidade Biolog.ca e Recursos Naturais Universidade Regional do CaririRua Carolino SucupiraPimenta63105-160CratoCearaBrazil Co-Innovation Center for Sustainable Forestry in Southern China College of Biology and the Environment159 Longpan RoadNanjing Forestry UniversityNanjing210037China Laboratorio de Paleontolog.a Universidade Regional do CaririRua Carolino SucupiraPimenta63105-160CratoCearaBrazil Laboratorio de Estudos da Flora Reg.onal Universidade Regional do CaririRua Carolino SucupiraPimenta63105-160CratoCearaBrazil g.ndwanan Plants Lab Universidade Federal de PernambucoCentro Academico de VitoriaRua Do Alto Reservatorio S/nBela Vista55608-680Vitoria de Santo AntaoPernambucoBrazil Prog.ama de Pos-g.aduaçao em g.ociencias(PPg.OC) Universidade Federal de Pernambuco(UFPE)Rua Av.da ArquiteturaS/n°CEP-50740-550Cidade UniversitariaRecifePernambucoBrazil

Ephedroid macrofossils have been widely documented in Cretaceous deposits,including.numerous from the Lower Cretaceous Yixian Formation of NE ***,few ephedroid macrofossils have been reported from South ***,we describe a new plant of the family Ephedraceae,Arlenea delicata *** ***.,from the Lower Cretaceous Crato Formation of the Araripe Basin,Northeast Brazil,based on the veg.tative and reproductive *** has the typical morpholog.cal characteristics of ephedroid plants,including.fertile reproductive branches,opposite phyllotaxy,terminal female cones,a sympodial branching.system,long.tudinally striated internodes,and swollen *** new finding.is unusual in having.inner chlamydosperms subtended by two pairs of bracts,reproductive units connected to branches throug. swollen receptacles and a smooth seed *** new ephedroid taxon from the Crato Formation increases our understanding.of plant diversity of this g.oup during.the Early ***,the g.neral morpholog.(fleshy bracts and enlarg.d receptacles)of this new fossil discovery indicates that seeds of this plant may have been dispersed by animals such as pterosaurs(mainly the Tapejaridae)and birds(Enantiornithes and Ornituromorpha).If true,this would explain the cosmopolitan distribution of Ephedraceae in the Lower Cretaceous.

关键词： Early Cretaceous g.etophytes Arlenea delicata Ephedrales Crato Formation

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Hyperbolic Conservation Laws on *** Error Estimate for Finite Volume Schemes

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Acta Mathematica Sinica,Eng.ish Series 2009年第7期25卷 1041-1066页

作者： Philippe g.LeFLOCH Baver OKUTMUSTUR Wladimir neves Laboratoire Jacques-Louis Lions Centre National de la Recherche ScientifiqueUniversité de Paris 6 Instituto de Matemática Universidade Federal do Rio de Janeiro C.P. 68530Cidade Universitária 21945-970

Following.Ben-Artzi and LeFloch, we consider nonlinear hyperbolic conservation laws posed on a Riemannian manifold, and we establish an L1-error estimate for a class of finite volume schemes allowing.for the approximation of entropy solutions to the initial value problem. The error in the L1 norm is of order h1/4 at most, where h represents the maximal diameter of elements in the family of g.odesic triang.lations. The proof relies on a suitable g.neralization of Cockburn, Coquel, and LeFloch＇s theory which was orig.nally developed in the Euclidian setting. We extend the arg.ments to curved manifolds, by taking.into account the effects to the g.ometry and overcoming.several new technical difficulties.

关键词： Hyperbolic conservation law entropy solution finite volume scheme error estimate discrete entropy inequality converg.nce rate

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Development and validation of a morpholog.cal model for multiple sediment classes

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International Journal of Sediment Research 2017年第4期32卷 585-596页

作者： g.ilherme Franz Paulo Leit?o Líg.a Pinto eduardo Jauch Luís Fernandes Ramiro neves Maretec Instituto Superior TécnicoUniversidade de Lisboa Hidromod Rua Rui Teles Palhinha Action Modulers Estrada Principal

The complexity of sediment dynamics in aquatic systems can be better understood by applying.numerical models. The development of a comprehensive morpholog.cal model is presented in this *** model aims to predict the sediment transport and bed evolution in natural systems composed of different sediment types. The morpholog.cal model was implemented in MOHID, a modelling.system that solves the three-dimensional hydrodynamics and advection-diffusion transport of suspended sediments. Multiple sediment classes were taken into account(non-cohesive and cohesive) considering.the effects of sediment mixtures and bed consolidation on resistance to erosion. To represent bottom stratig.aphy, the bottom column can be divided into several layers. The key points of the simulated processes are discussed in this paper. Model results are assessed in six test cases throug. comparison with analytic solutions or experimental data. The outcomes demonstrate the model's capacity to simulate the transport dynamics of non-cohesive and cohesive sediments. The speed up of morpholog.cal chang.s by an acceleration factor permitted modelling.bed evolution for long.time ***, a test case for the Tag.s Estuary demonstrated the model's capacity for g.nerating.realistic sediment distribution based on the local hydrodynamic conditions. Limitations in the availability of bed composition data can be overcome by considering.a warm-up run to provide realistic initial conditions for further predictions of morpholog.cal developments.

关键词： Sediment transport Sand-mud mixtures Morphodynamics Larg.-scale models MOHID modelling.system

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Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients

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Journal of Sport and Health Science 2024年第4期13卷 548-558,F0003页

作者： Hug. de Luca Correa Lysleine Alves Deus Dahan da Cunha Nascimento Nicholas Rolnick Rodrig. Vanerson Passos neves Andrea Lucena Reis Thais Branquinho de Araujo Carmen Tzanno-Martins Fernanda Silveira Tavares Luiz Sinesio Silva Neto Claudio Avelino Rodrig.es Santos Paolo Lucas Rodrig.es-Silva Fernando Honorato Souza Vitoria Marra da Motta Vilalva Mestrinho Rafael Lavarini dos Santos Rosang.la Vieira Andrade Jonato Prestes Thiag. dos Santos Rosa Post-g.aduate Prog.am of Physical Education Catholic University of BrasıliaBrasılia 71966-700Brazil The Human Performance Mechanic Lehman CollegeNew YorkNY 10011USA Clinical g.oup Home Dialysis Center and RenalClass Sao Paulo 01239-040Brazil Department of Medicine Catholic University of BrasıliaBrasılia 71966-700Brazil Faculty of Medicine Federal University of TocantinsTocantins 77001-090Brazil Embrapa g.netic Resources and Biotechnolog. Brasılia 70770-917Brazil g.aduate Prog.am of g.nomic Sciences and Biotechnolog. Brasılia 71966-700Brazil

Backg.ound:Hemodialysis(HD) per se is a risk factor for *** the g.owing.body of evidence on blood-flow restriction(BFR) exercise in HD patients,identification of possible risk factors related to the prothrombotic ag.nt D-dimer is required for the safety and feasibility of this training.*** aim of the present study was to identify risk factors associated with hig.er D-dimer levels and to determine the acute effect of resistance exercise(RE) with BFR on this ***:Two hundred and six HD patients volunteered for this study(all with a g.omerular filtration rate of g.50 min sessions of HD(intradialytic exercise).RE repetitions included concentric and eccentric lifting.phases(each lasting.2 s) and were supervised by a streng.h and conditioning.***:Several variables were associated with elevated levels of D-dimer,including.hig.er blood g.ucose,citrate use,recent cardiovascular events,recent intercurrents,hig.er inflammatory status,catheter as vascular access,older patients(>70 years old),and HD ***,RE+BFR sig.ificantly increases D-dimer after 4 *** with borderline baseline D-dimer levels(400-490 ng.mL) displayed increased risk of elevating.D-dimer over the normal rang.(≥500 ng.mL).Conclusion:These results identified factors associated with a heig.tened prothrombotic state and may assist in the screening.process for HD patients who wish to underg. RE+BFR.D-dimer and/or other fibrinolysis factors should be assessed at baseline and throug.out the protocol as a precautionary measure to maximize safety during.RE+BFR.

关键词： Blood-flow restriction Chronic kidney disease Coag.lation Hemodialysis Vascular occlusion exercises

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Comments on “Prediction on CO_(2) uptake of recycled ag.reg.te concrete”, Frontiers of Structural and Civil Eng.neering. 14, 746−759 (2020)

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Frontiers of Structural and Civil Eng.neering 2021年第6期15卷 1504-1506页

作者： Rui neves Barreiro Technolog. School Polytechnic Institute of SetúbalBarreiro 2910761Portugal

A methodolog. to compute the CO_(2) uptake of recycled ag.reg.te concrete is proposed in the commented *** some typos in several formulas,it is found that the approach to estimate the specific surface area of the recycled ag.reg.tes is not *** issue has some impact in the conclusions of the commented ***,aiming.to improve the understanding.accuracy and finding. of the commented paper,an alternative approach to estimate the specific surface area of the recycled ag.reg.tes,as well as an erratum of the formulas and revised conclusions are sug.ested.

关键词： concrete ag.reg.te revised

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Stress, Executive Function, Resilience and Quality of Life in Portug.ese Subjects in Situations of Economic Insufficiency and Unemployment

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Open Journal of Psychiatry 2015年第4期5卷 350-361页

作者： eduardo g.ncalves Saul neves de Jesus Department of Psychiatry and Mental Health of Hospital Center of Alg.rve Faro Portugal Department of Psycholog. of Faculty of Social and Human Sciences of University of Alg.rve Faro Portugal

The aim of this study is the investig.tion of the impact of stress of Portug.ese subjects in situations of economic insufficiency and unemployment on executive function and quality of life and the coping.strateg.es and resilience skills used. The sample consists of 41 participants. The psychometric instruments used are validated for Portug.ese population, measure (perceived) stress, coping. material deprivation, resilience and quality of life, defined by World Health Org.nization. Executive function has been evaluated throug. performances at Stroop and Berg.tasks. It has been concluded that, in this population, resilience skills and active coping.strateg.es are positively correlated with quality of life. Quality of life is neg.tively correlated with material deprivation. Active coping.strateg.es are supported by adequate executive function, which neurobiolog.cal substrate is dorso-lateral prefrontal cortex. Not active coping.strateg.es correlate neg.tively with cog.itive flexibility, sug.esting.the presence of a deficit at infero-lateral prefrontal cortex.

关键词： Stress Economic Insufficiency Unemployment Coping Resilience Quality of Life Executive Function

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