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Prediction of Forming Limit Diagrams for materials with HCP Structure

Acta metallurgica Sinica(English Letters) 2015年第12期28卷 1442-1451页

作者： Sheng-Hua Wu Nan-Nan Song Francisco m.Andrade Pires Abel D.santos Faculty of Engineering University of Porto INEGI University of Porto

The forming limit diagram（FLD） is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timeconsuming and therefore the analytical prediction based on theory of plasticity and instability criteria allows a direct and efficient methodology to obtain critical values at different loading paths, thus carrying significant practical ***, the accuracy of the plastic instability prediction is strongly dependent on the choice of the material constitutive model [1–3]. Particularly for materials with hexagonal close packed（HCP） crystallographic structure, they have a very limited number of active slip systems at room temperature and demonstrate a strong asymmetry between yielding in tension and compression [4, 5]. Not only the magnitude of the yield locus changes, but also the shape of the yield surface is evolving during the plastic deformation [4]. Conventional phenomenological constitutive models of plasticity fail to capture this unconventional mechanical behavior [4, 6]. Cazacu and Plunkett [6] have proposed generic yield criteria, by using the transformed principal stress, to account for the initial plastic anisotropy and strength differential（SD） effect simultaneously. In this contribution, a generic FLD mATLAB script was developed based on marciniak–Kuczynski analytical theory and applied to predict the localized necking. The influence of asymmetrical effect on the FLD was evaluated. Several yield functions such as von mises, Hill, Barlat89, and Cazacu06 were incorporated into analysis. The paper also presents and discusses the influence of different hardening laws on the formability of materials with HCP crystal structures. The findings indicate that the plastic instability theory coupled with Cazacu model can adequately predict the onset of localized necking for HCP materials under different strain paths.

关键词： Forming limit diagram(FLD) marciniak–Kuczynski analysis Plastic instability Yield function Hardening law

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The effect of drying of Piper hispidinervium bydifferent methods and its influence on the yield ofessential oil and safrole

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Information Processing in Agriculture 2023年第1期10卷 28-39页

作者： Helder Kiyoshi miyagawa Alberdan Silva santos Systematic Investigation in Biotechnology and molecular Biodiversity Laboratory Federal University of Para´Bele´m 66075-110PABrazil

The Piper hispidinervium leaves and thin stems were dried under laboratory and field *** drying was performed using a shade dryer operating with and without forced convection and an oven dryer operating at 30 and 40*** experiments were conducted using solar dryers with three different covers,i.e.,transparent,black plastic,and palm straw *** essential oil extraction was performed by steam distillation,and the safrole content was analyzed by gas *** mathematical models(Page,logarithmic,Henderson and Pabis,fractional,and diffusion)were fitted with the experimental data and compared based on the coefficient of determination(R2),root mean square error(RmSE)and *** suggest that the best model was the logarithmic model(R2>0.99,RmSEme was prolonged,both the oil yield and safrole content of the extracted oil decreased.

关键词： modeling Drying kinetics Essential oil extraction Safrole extraction Piperaceae

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Complexed amino acid minerals ***-glycinate chelated minerals:Impact on the performance of old laying hens

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Animal Nutrition 2024年第1期16卷 395-408页

作者： marcos J.B.santos maria C.m.m.Ludke Leandro m.Silva Carlos B.V.Rabello mércia R.Barros Fabiano S.Costa Clariana S.santos Jamille S.S.Wanderley Department of Animal Science Rural Federal University of PernambucoRecifePEBrazil Department of Veterinary Science Rural Federal University of PernambucoRecifePEBrazil

The present study was to evaluate the effect of trace minerals(Zn,mn,and Cu)from complexed amino acid minerals(ZmCAA)and bis-glycinate chelated minerals(ZmCGly)in laying hen diets on performance,internal and external egg quality,yolk mineral deposition,intestinal morphometry,and bone *** 78 to 98 weeks of age,400 White LSL-Lite strain laying hens were distributed in a randomized design with 4 treatments with 10 replicates per *** were distributed in a 2×2 factorial arrangement using either Zn,mn,and Cu of ZmCAA or ZmCGly source at 2 levels:low(20,20,and 3.5 mg/kg of Zn,mn,and Cu,respectively)or high(40,40,and 7 mg/kg of Zn,mn,and Cu,respectively).The analysis of variance was performed,and in cases where differences were observed,the means were compared using Tukey?s test(Pmineral supplementation had a significant impact on the performance of laying *** fed ZmCAA had higher egg production(P=0.01),egg weight(P=0.02),egg mass(P=0.01),and lower feed conversion ratio(P=0.05)compared to those fed *** ZmCAA supplementation showed higher albumen height(P=0.01),albumen weight(P=0.01),and eggshell thickness(Pmn(Pmetry(PmCAA *** the small intestine,ZmCAA resulted in longer villi(P=0.02)and shorter crypt depth(P=0.01)in the *** and ileum measurements were influenced by the level and source of trace minerals(PmCAA exhibited superior performance,egg quality,deposition of trace minerals in the egg yolk,and bone density compared to hens fed *** this study,older laying hens supplemented with ZmCAA at lower levels demonstrated adequate levels of supplementation.

关键词： Bis-glycinates metal-amino acids Radiodensity Trace minerals

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Real drive cycles analysis by ordered power methodology applied to fuel consumption,C0_(2),NO_(x) and Pm emissions estimation

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Frontiers of Environmental Science & Engineering 2021年第1期15卷 77-90页

作者： Pol masclans Abello Vicente medina Iglesias m.Antonia de los santos Lopez Jesus Alvarez-Florez Center for Engines and Heat Installation Research(CREmIT-UPC).Universitat Politecnica de Catalunya-BarcelonaTech.Av.Diagonal 547(ETSEIB)08028 Barcelona Spain Department of Thermal machinery of Universitat Politecnica de Catalunya-BarcelonaTech and CREmIT-UPC.-BarcelonaTech.Av.Diagonal 547(ETSEIB)08028 Barcelona Spain 3 Department of mechanical Engineering of Universitat Politecnica de Catalunya-BarcelonaTech and CREmIT-UPC.-BarcelonaTech.Av.Diagonal 547(ETSEIB)08028 Barcelona Spain

In this work three fuel consumption and exhaust emission models,ADVISOR,VT-mICRO and the European Environmental Agency Emission factors,have been used to obtain fuel consumption(FC)and exhaust *** models have been used at micro-scale,using the two signal treatment methods *** manuscript presents:1)a methodology to collect data in real urban driving cycles,2)an estimation of FC and tailpipe emissions using some available models in literature,and 3)a novel analysis of the results based on delivered wheel *** results include Fuel Consumption(FC),CO_(2),NO_(x) and Pm_(10) emissions,which are derived from the three *** the first part of the paper we present a new procedure for incomplete drive cycle data treatment,which is necessary for real drive cycle acquisition in high density *** the models are used to obtain second by second FC and exhaust ***,a new methodology named Cycle Analysis by Ordered Power(CAbOP)is presented and used to compare the *** method consists in the re-ordering of time dependant data,considering the wheel mechanical power domain instead of the standard time *** new strategy allows the 5 situations in drive cycles to be clearly visualized:hard breaking zone,slowdowns,idle or stop zone,sustained speed zone and acceleration *** complete methodology is applied in two real drive cycles surveyed in Barcelona(Spain)and the results are compared with a standardized WLTC urban cycle.

关键词： Cycle Analysis by Ordered Power(CAbOP) micro and macro models Real drive cycle NO_(x)/Pm_(10)/CO_(2)emissions Wheel mechanical power domain Worldwide Harmonized Light-Duty Vehicles Test Cycle(WLTC)

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A critical review towards the causes of the iron-based catalysts deactivation mechanisms in the selective oxidation of hydrogen sulfide to elemental sulfur from biogas

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Journal of Energy Chemistry 2024年第3期90卷 388-411,I0010页

作者： mostafa Tarek Janaina S.santos Victor márquez mohammad Fereidooni mohammad Yazdanpanah Supareak Praserthdam Piyasan Praserthdam Center of Excellence on Catalysis and Catalytic Reaction Engineering(CECC) Department of Chemical EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailan High-Performance Computing Unit(CECC-HCU) Center of Excellence on Catalysis and Catalytic Reaction Engineering(CECC)Chulalongkorn UniversityBangkok 10330Thailand

Hydrogen sulfide(H_(2)S) not only presents significant environmental concerns but also induces severe corrosion in industrial equipment,even at low *** various technologies,the selective oxidation of hydrogen sulfide(SOH_(2)S) to elemental sulfur(S) has emerged as a sustainable and environmentally friendly *** to its unique properties,iron oxide has been extensively investigated as a catalyst for SOH_(2)S;however,rapid deactivation has remained a significant *** causes of iron oxide-based catalysts deactivation mechanisms in SOH_(2)S,including sulfur or sulfate deposition,the transformation of iron species,sintering and excessive oxygen vacancy formation,and active site loss,are thoroughly examined in this *** focusing on the deactivation mechanisms,this review aims to provide valuable insights into enhancing the stability and efficiency of iron-based catalysts for SOH_(2)S.

关键词： Selective oxidation of H_(2)S Iron-based Catalysts mechanism of deactivation Sulfur or sulfate deposition Transformation of iron species Sintering SDG 7

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Analysis of 12 variants in the development of gastric and colorectal cancers

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World Journal of Gastroenterology 2017年第48期23卷 8533-8543页

作者： Giovanna C Cavalcante marcos AT Amador Andre m Ribeiro dos santos Darlen C Carvalho Roberta B Andrade Esdras EB Pereira marianne R Fernandes Danielle F Costa Ney PC santos Paulo P Assumpcao Andrea Ribeiro dos santos Sidney santos Laboratório de Genética Humana e médica Universidade Federal do Pará Núcleo de Pesquisas em Oncologia Universidade Federal do Pará

AIm To evaluate the relation between 12 polymorphisms and the development of gastric cancer(GC) and colorectal cancer(CRC).mETHODS In this study,we included 125 individuals with GC diagnosis,66 individuals with CRC diagnosis and 475 cancer-free individuals. All participants resided in the North region of Brazil and authorized the use of their samples. The 12 polymorphisms(in CASP8,CYP2 E1,CYP19 A1,IL1 A,IL4,mDm2,NFKB1,PAR1,TP53,TYmS,UGT1 A1 and XRCC1 genes) were genotyped in a single PCR for each individual,followed by fragment analysis. To avoid misinterpretation due to population substructure,we applied a previously developed set of 61 ancestryinformative markers that can also be genotyped by multiplex PCR. The statistical analyses were performed in Structure v.2.3.4,R environment and SPSS *** After statistical analyses with the control of confounding factors,such as genetic ancestry,three markers(rs79071878 in IL4,rs3730485 in mDm2 and rs28362491 in NFKB1) were positively associated with the development of GC. One of these markers(rs28362491) and the marker in the UGT1 A1 gene(rs8175347) were positively associated with the development of CRC. Therefore,we investigated whether the joint presence of the deleterious alleles of each marker could affect the development of cancer and we obtained positive results in all analyses. Carriers of the combination of alleles RP1 + DEL(rs79071878 and rs28361491,respectively) are at 10-times greater risk of developing GC than carriers of other combinations. Similarly,carriers of the combination of DEL + RARE(rs283628 and rs8175347) are at about 12-times greater risk of developing CRC than carriers of other *** These findings are important for the comprehension of gastric and CRC development,particularly in highly admixed populations,such as the Brazilian population.

关键词： Inflammatory processes Immune response Genomic and cellular stability Gastric cancer Colorectal cancer Amazon

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Resistance of full-scale beams against close-in *** modeling and field tests

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Defence Technology（防务技术） 2024年第10期40卷 35-47页

作者： A.Prado A.Alañón R.Castedo A.P.santos L.m.López m.Chiquito m.Bermejo C.Oggeri Escuela Politécnica Superior dé Avila Universidad de SalamancaÁvila05003Spain E.T.S.I.minas y Energía Universidad Politecnica de MadridMadrid28003Spain Department of Engineering Aviation and TechnologySaint Louis UniversityMadrid28003Spain Department of Environment Land and Infrastructure Engineering(DIATI)Politecnico di TorinoTorino10129Italy

This paper explores the performances of a finite element simulation including four concrete models applied to a full-scale reinforced concrete beam subjected to blast loading. Field test data has been used to compare model results for each case. The numerical modelling has been, carried out using the suitable code LS-DYNA. This code integrates blast load routine(CONWEP) for the explosive description and four different material models for the concrete including: Karagozian & Case Concrete, Winfrith, Continuous Surface Cap model and Riedel-Hiermaier-Thoma models, with concrete meshing based on 10, 15, and 20 mm. Six full-scale beams were tested: four of them used for the initial calibration of the numerical model and two more tests at lower scaled distances. For calibration, field data obtained employing pressure and accelerometers transducers were compared with the results derived from the numerical simulation. Damage surfaces and the shape of rupture in the beams have been used as references for comparison. Influence of the meshing on accelerations has been put in evidence and for some models the shape and size of the damage in the beams produced maximum differences around 15%. In all cases, the variations between material and mesh models are shown and discussed.

关键词： Blast test Numerical simulation LS-DYNA Concrete model mesh effect Full-scale beams

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Nonlocal material properties of single-walled carbon nanotubes

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International Journal of Smart and Nano materials 2012年第2期3卷 141-151页

作者： J.V.Araújo dos santos C.m.mota Soares IDmEC Instituto Superior TécnicoUniversidade Técnica de Lisboa1049-001 LisboaPortugal

Natural frequencies of single-walled carbon nanotubes(SWCNTs)obtained using a model based on Eringen’s nonlocal continuum mechanics and the Timoshenko beam theory are compared with those obtained by molecular dynamics *** goal was to determine the values of the material constant,considered here as a nonlocal property,as a function of the length and the diameter of *** present approach has the advantage of eliminating the SWCNT thickness from the computations.A sensitivity analysis of natural frequencies to changes in the nonlocal material constant is also carried out and it shows that the influence of the nonlocal effects decreases with an increase in the SWCNT *** matching of natural frequencies shows that the nonlocal material constant varies with the natural frequency and the SWCNT length and diameter.

关键词： nonlocal mechanics molecular dynamics simulation single-walled carbon nanotube Timoshenko beam

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Use of improved cold-finger technique to assess effects of basicity on heat transfer through solidified mold flux

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Journal of Iron and Steel Research International 2019年第4期26卷 393-402页

作者： Karina Lara santos Assis Petrus Christiaan Pistorius Department of materials Science and Engineering Center for Iron and Steelmaking ResearchCarnegie Mellon UniversityPittsburgh 15213PAUSA

Cold-finger measurements were used to estimate the contact resistance and average thermal conductivity of mold flux films solidified on a water-cooled copper *** industrial mold fluxes,with basicities from low to high,were *** steady-state rate of convective heat transfer between the solid film and liquid flux was compared with calculations based on natural convection correlations;the comparison indicates that the surface of the solid film(in contact with molten flux)is approximately at its solidus *** roughness of the mold flux film in contact with copper was larger for films grown from higher-temperature mold flux and for higher-basicity mold *** glassy(low-basicity)film had an estimated thermal conductivity of 1.1 W/(m K).The crystalline or partially crystalline films had higher estimated thermal conductivities of 2.2-3.2 W/(m K).The measured values of thermal resistance were extrapolated to typical mold flux film thicknesses for industrial conditions;the extrapolations confirmed that the high contact resistance of higher-basicity mold fluxes can yield higher thermal resistances than the low-basicity *** morphology of the rough interface of higherbasicity mold flux films that gives the higher contact resistance is consistent with that observed in previous work and appears not to be directly related to crystallization.

关键词： mold flux Heat transfer Conduction Contact resistance-Cold-finger technique

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Anthropogenic land use substantially increases riverine CO_(2) emissions

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Journal of Environmental Sciences 2022年第8期34卷 158-170页

作者： Shijie Gu Siyue Li Isaac R.santos School of River and Ocean Engineering Chongqing Jiaotong UniversityChongqing 400074China Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Chongqing School University of Chinese Academy of SciencesChongqing 400714China Research Center for Environmental Ecology and Engineering Institute of Changjiang Water Environment and Ecological SecuritySchool of Environmental Ecology and Biological EngineeringKey Laboratory for Green Chemical Process of Ministry of EducationKey Laboratory of Novel Reactor and Green Chemical Technology of Hubei ProvinceEngineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationWuhan Institute of TechnologyWuhan 430205China Department of marine Sciences University of GothenburgGothenburg 41296Sweden National marine Science Centre Southern Cross UniversityCoffs HarbourNSW 2450Australia

Carbon dioxide(CO_(2)) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO_(2) emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO_(2) partial pressures(pCO_(2)) and degassing in a monsoonal river(Yue River)within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO_(2) with a mean ± standard deviation of 1474 ± 1614 μatm, leading to emissions of 557-971 mmol/m^(2)/day from river water to the atmosphere. Annual CO_(2) emissions were 1.6-2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO_(2) was positively correlated to anthropogenic land use(urban and farmland), and negatively correlated to forest cover. p CO_(2) also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict p CO_(2) . Farmland and urban land released nutrients and organic matter to the river system, driving riverine p CO_(2) enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO_(2) , which should be considered in future large-scale estimates of CO_(2) emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers.

关键词： River carbon Inland waters Greenhouse gases Climate change Water quality Headwater streams

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