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Journal of Materials Science & Technology 2022年第3期98卷 123-135页

作者： r.Silva g.S.Vacchi C.L.Kugelmeier i.g.r.santos A.A.Mendes Filho D.C.C.Magalhães C.r.M.Afonso V.L.Sordi C.A.D.rovere Munir rachid Corrosion Laboratory Department of Materials EngineeringFederal University of São CarlosRodovia Washington Luis Km 23513565-905 São CarlosSPBrazil Engineering Modeling and Applied Social Sciences Center(CECS)Federal University of ABCAvenida dos Estados 500109210580 Santo AndréSPBrazil Federal University of São Carlos Graduate Program in Materials Science and EngineeringBrazil

in this study,the relationship between spinodal decomposition and the formation of Ni-rich clusters and g-phase in the ferrite on hardening and pitting corrosion of two thermally aged duplex stainless steels(DSSs)at 475℃was *** indicate that,for 2205 DSS,pitting corrosion behavior is influenced by the presence and size of g-phase precipitates for longer aging times,but this contribution is masked by the advanced stage of spinodal decomposition in the ferritic *** the other hand,for 2101 DSS,the formation of Cr-richer nitrides impairs pitting corrosion resistance more than spinodal decomposition.

关键词： Duplex stainless steel Spinodal decomposition g-phase precipitation Pitting corrosion Hardening

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

Ultrafast laser-driven topological spin textures on a 2D magnet

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npj Computational Materials 2022年第1期8卷 1630-1635页

作者： Mara Strungaru Mathias Augustin Elton J.g.santos institute for Condensed Matter Physics and Complex Systems School of Physics and AstronomyThe University of EdinburghEdinburghEH93FDUK Donostia international Physics Center(DiPC) 20018Donostia-San SebastiánBasque CountrySpain Higgs Centre for Theoretical Physics The University of EdinburghEdinburghEH93FDUK

Ultrafast laser excitations provide an efficient and low-power consumption alternative since different magnetic properties and topological spin states can be triggered and manipulated at the femtosecond(fs)***,it is largely unknown whether laser excitations already used in data information platforms can manipulate the magnetic properties of recently discovered two-dimensional(2D)van der Waals(vdW)*** we show that ultrashort laser pulses(30−85 fs)can not only manipulate magnetic domains of 2D-XY CrCl_(3)ferromagnets,but also induce the formation and control of topological nontrivial meron and antimeron spin *** observed that these spin quasiparticles are created within~100 ps after the excitation displaying rich dynamics through motion,collision and annihilation with emission of spin waves throughout the *** findings highlight substantial opportunities of using photonic driving forces for the exploration of spin textures on 2D magnetic materials towards magneto-optical topological applications.

关键词： laser excitation topological

role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions:a molecular dynamics study

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Petroleum Science 2020年第3期17卷 797-810页

作者： H.santos Silva A.Alfarra g.Vallverdu D.Bégué B.Bouyssiere i.Baraille institut des Science Analytiques et Physico-Chimie pour l’Environnement et les Materiaux UMR 5254CNRS/Univ Pau&Pays Adour64000 PauFrance Total research and Technology GonfrevilleBP 2776700 HarfleurFrance Joint Laboratory C2MC:Complex Matrices Molecular Characterization Total Research and TechnologyGonfrevilleBP 2776700 HarfleurFrance

Breaking water-in-oil emulsions during the refining of crude oils is an important step before any upgrading process is *** molecules are incriminated as playing an important role in this *** the mechanisms behind the affinity between them and water is a key step to understand how to break these emulsions more easily and require lower amounts of *** which demulsifier molecule(s)to use is also primordial,but to do so rationally,one needs to know which are the molecular interactions in place between asphaltenes,porphyrins and water so that demulsifiers are chosen to destabilize a specific physical–chemical *** this paper,we study the interactions arising between asphaltenes and porphyrins and six different molecules potentially displaying a demulsification action in the presence of water/oil *** demonstrate that the ionic demulsifier molecules present an interesting potential to either interact strongly with water,replacing asphaltenes in this interaction,or to interact with the active sites of asphaltenes,deactivating them and avoiding any asphaltenic interfacial ***,we also found that although asphaltenes do not migrate spontaneously toward the water/oil interfaces,porphyrins do so rather *** indicates that porphyrins do have an important activity at the water/oil interface.

关键词： Asphaltenes aggregation Petroporphyrins Molecular dynamics Emulsion Water-oil interface Demulsifiers

Asphaltene aggregation studied by molecular dynamics simulations:role of the molecular architecture and solvents on the supramolecular or colloidal behavior

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Petroleum Science 2019年第3期16卷 669-684页

作者： H.santos Silva A.Alfarra g.Vallverdu D. Begue B.Bouyssiere i.Baraille institut des Science Analytiques et Physico-Chimie pour l'Environnement et les Materiaux UMR 5254 CNRS/Univ Pau and Pays Adour 64000 Pau France Total research and Technology BP 2776700 Gonfreville Harfleur France Joint Laboratory C2MC: Complex Matrices Molecular Characterization Total Research and Technology BP 2776700 Gonfreville Harfleur France

Asphaltene aggregation is a subject under vivid discussion:There are several parameters one needs to determine before its behavior can be mastered and better target solutions can be *** nature of asphaltene aggregation(colloidal or supramolecular)and the role of solvents and their mixtures are among the least understood parameters in asphaltene *** paper addresses molecular dynamic simulations to correlate the aggregation properties of asphaltenes,their molecular structure and the concentration of these *** show that the formation of the nanoaggregate depends,primarily,on the size of the conjugated core and on the eventual presence of polar groups capable of forming *** on the conjugated core do not change their shape or type of aggregation but may induce stronger π-π *** macroaggregation formation depends upon the length of the lateral chains of asphaltenes and also on the presence of polar groups at its ***,n-heptane and water may interact selectively with asphaltenes in function of their molecular *** this fact and the aggregation behavior observed,we advocate toward the assumption that a colloidal behavior of asphaltenes might be a particular case of a more general model,based on a supramolecular description.

关键词： Asphaltenes Molecular dynamics Aggregation Heavy oil

Determination of the physical and interaction properties of sorghum grains:Application to computational fluid dynamics-discrete element method simulations of the fluid dynamics of a conical spouted bed

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Particuology 2021年第1期19卷 91-101页

作者： J.N.M.Batista D.A.santos r.Bettega Federal University of São Carlos Department of Chemical EngineeringSPBrazil institute of Chemistry Federal University of GoiásGOBrazil

Computational simulation is an important tool for design and improvement of industrial *** fluid dynamics(CFD)coupled with the discrete element method(DEM)has been applied to simulate drying equipment that usually involves gas-solid *** reliable results of CFD-DEM simulations,the properties related to the interactions of the material within the industrial equipment,such as the restitution or friction coefficients,must be *** this study,CFD-DEM was applied to simulate the fluid dynamics inside a conical spouted bed operating with sorghum *** physical properties of the particulate phase and the particle-particle and particle-wall interaction parameters were determined by the direct measurement approach and applied to *** interaction parameters were experimentally determined,including the particle-particle interaction parameters ofη=0.46,μ^(S)=0.79,andμ_(r)=0.70,and the particle-wall interaction parameters ofη=0.56,μ_(S)=0.75,andμ_(r)=*** simulated minimum spouting velocity and characteristic curves were compared with the experimental *** was good agreement between the simulated and experimental results.

关键词： restitution coefficient Static friction coefficient rolling friction coefficient CFD DEM

Spouting behavior of binary particle mixtures of different densities: Fluid dynamics and particle segregation

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Particuology 2019年第1期17卷 58-66页

作者： K.g. santos r.C. Santana D.L. Souza V.V. Murata M.A.S. Barrozo Federal University ofTriangulo Mineiro Chemical Engineering DepartmentUniverdecidade CampusUberabaMGBrazil Federal University of Uberlandia Chemical Engineering SchoolUberlandiaMG. Brazil

Numerous industrial applications of spouted beds involve a mixture of granular particles, where differences in particle size, density, and shape can cause particle segregation, affecting the quality of flow and decreasing product homogeneity. The aim of this study was to investigate the particle segregation and fluid dynamics of a conical spouted bed operating with a binary mixture of particles of different densities. Using glass beads and polyethylene particles with a diameter of 4 mm, we determined the effects of the mass fraction of denser particles and static bed height on the minimum spouting condition and mixture index. The pressure drop and airflow in the minimum spouting condition increased with an increase in bed height or jetsam concentration. regarding particle segregation, the jetsam particles tended to concentrate near the bottom, at the spout–annulus interface because they have a shorter trajectory than the lighter particles in the fountain region. Jetsam-rich mixtures with high initial static bed heights exhibited more efficient particle mixing, excluding those at the bottom of the bed.

关键词： Density Segregation Spouted bed Binary mixtures

Comment on “Constraining the smoothness parameter and dark energy using observational H(z) data”

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research in Astronomy and Astrophysics 2011年第6期11卷 637-640页

作者： V.C.Busti r.C.santos instituto de Astronomia Geofísica e Ciências AtmosféricasUniversidade de So PauloSo Paulo05508-090 SPBrazil Departamento de Ciê ncias Exatas e da Terra Universidade Federal de So Paulo(UNIFESP)Diadema09972-270 SPBrazil

We discuss a recent analysis by Yu et al.[rAA 11,125（2011）] about constraints on the smoothness parameter α and dark energy models using observational H（z） *** is argued here that their procedure is conceptually inconsistent with the basic assumptions underlying the adopted Dyer-roeder *** order to properly quantify the influence of the H（z） data on the smoothness parameter α,a χ2-test involving a sample of type ia supernovae and H（z） data in the context of a flat ΛCDM model is *** result is confronted with an earlier approach discussed by santos et al.（2008） without H（z） *** the（Ωm,α） plane,it is found that such parameters are now restricted to be in the intervals 0.66 ≤ α ≤ 1.0 and 0.27 ≤ Ωm ≤ 0.37 within the 95.4 confidence level（2σ）,and,therefore,are fully compatible with the homogeneous *** basic conclusion is that a joint analysis involving H（z） data can indirectly improve our knowledge about the influence of the ***,this happens only because the H（z） data provide tighter constraints on the matter density parameter Ωm.

关键词： cosmology — dark energy — cosmological parameters

Fluorescent probes for the detection of reactive oxygen species in human spermatozoa

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Asian Journal of Andrology 2020年第5期22卷 465-471页

作者： Sara Escada-rebelo Francisca g Mora Ana P Sousa Teresa Almeida-santos Artur Paiva Joao ramalho-santos phD Programme in Experimental Biology and Biomedicine CNC-Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbra 3004-504Portugal Biology of reproduction and Stem Cell group CNC-Center for Neuroscience and Cell BiologyUniversity of CoimbraCoimbra 3004-504Portugal iiiUC-institute for interdisciplinary research Casa Costa AlemaoUniversity of CoimbraCoimbra 3030-789Portugal reproductive Medicine Unit University Hospitals of CoimbraCoimbra 3004-561Portugal Faculty of Medicine University of CoimbraCoimbra 3000-370Portugal Clinical Pathology Unit University Hospitals of CoimbraCoimbra 3004-561Portugal Department of Life Sciences University of CoimbraCoimbra 3000-456Portugal

reactive oxygen species(rOS)production is a by-product of mitochondrial activity and is necessary for the acquisition of the capacitated state,a requirement for functional ***,an increase in oxidative stress,due to an abnormal production of rOS,has been shown to be related to loss of sperm function,highlighting the importance of an accurate detection of sperm rOS,given the specific nature of this *** this work,we tested a variety of commercially available fluorescent probes to detect rOS and reactive nitrogen species(rNS)in human sperm,to define their *** both flow cytometry(FC)and fluorescence microscopy(FM),we confirmed that MitoSOX™red and dihydroethidium(DHE)detect superoxide anion(as determined using antimycin A as a positive control),while DAF-2A detects reactive nitrogen species(namely,nitric oxide).For the first time,we also report that redoxSensor™red CC-1,CellrOX®Orange reagent,and MitoPYl seem to be mostly sensitive to hydrogen peroxide,but not ***,mean fluorescence intensity(and not percentage of labeled cells)is the main parameter that can be reproducibly monitored using this type of methodology.

关键词： flow cytometry fluorescent probes human spermatozoa oxidative stress reactive oxygen species

influence of variables on the synthesis of CoFe_(2)O_(4)pigment by the complex polymerization method

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Journal of Advanced Ceramics 2015年第2期4卷 135-141页

作者： P.N.MEDEirOS Y.F.gOMES M.r.D.BOMiO i.M.g.santos M.r.S.SiLVA C.A.PASKOCiMAS M.S.Li F.V.MOTTA Department of Materials Engineering Federal University of Rio Grande do NorteCampus Lagoa NovaCEP 59078-900-Natal/RNBrazil Department of Chemistry Federal University of ParaíbaCidade UniversitáriaCEP 58051-900-João Pessoa/PBBrazi institute Physics of São Carlos USPCEP 13566-590São CarlosSão PauloBrazil

Synthetic inorganic pigments are most widely used in ceramic applications due to their excellent chemical and thermal stability and their lower toxicity to both human and environment as *** the present work,black ceramic pigment CoFe_(2)O_(4)has been synthesized by the complex polymerization method(CPM)with good chemical *** order to study the influence of variables on the process of obtaining pigment through CPM,2^((5-2))fractional factorial design with resolution iii was *** variables studied in the mathematical modeling were:citric acid/metal concentration,pre-calcination time,calcination temperature,calcination time,and calcination *** pigments were characterized by X-ray diffraction(XrD),scanning electron microscopy(SEM),and UV-visible(UV-Vis)*** on the results,the formation of cobalt ferrite phase(CoFe_(2)O_(4))with spinel structure was *** color of pigments obtained showed dark shades,from black to *** model adjusted to the conditions proposed in this study due to the determination coefficient of 99.9%and variance(r²)showed that all factors are significant at the confidence level of 95%.

关键词： pigment complex polymerization method(CPM) fractional factorial design