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Green Method, Optical and Structural Characterization of ZnO Nanoparticles Synthesized Using Leaves Extract of M. oleifera

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Journal of Renewable Materials 2022年第3期10卷 833-847页

作者： Jose Vulfrano Gonzalez-Fernandez Diego David Pinzon-Moreno Antony Alexander Neciosup-Puican Maria Veronica Carranza-Oropeza facultad de Quimica e ingenieria Quimica Universidad Nacional Mayor de San MarcosLima15081Peru Centro de Investigaciones Tecnologicas Biomedicas y MedioambientalesUniversidad Nacional Mayor de San MarcosLima15081Peru

ZnO nanoparticles(ZnO-NP)present innovative optical,electrical,and magnetic properties that depend on spe-cific characteristics,e.g.,size,distribution,and ***,these properties are essential to address various applications in areas such as electronics,medicine,energy,and *** addition,the performance of this ZnO-NP depends of their preparation which can be done by chemical,physical,and biological ***,nowadays,the main interest in developing ZnO-NP synthesis through biological methods bases on the decrease of use of toxic chemicals or energy applied to the procedures,making the process more cost-effective and environ-mentally ***,the large-scale production of nanoparticles by green synthesis remains a big challenge due to the complexity of the biological extracts used in chemical *** being the case,the preparation of ZnO-NP using Moringa oleifera extract as an alternative biological agent for capping and reduction in synthesis was evaluated in this ***,the results based on the analysis of the optical and structural characterization of the ZnO-NP obtained by employing UV-Vis,DLS,zeta potential,XRD,ATR-FTIR,and FE-SEM indicate mostly the presence of spherical nanosized material with a mean hydrodynamic diameter of 47.2 nm measured by DLS and a mean size diameter of 25 nm observed with FE-SEM ***,in FE-SEM images a homo-geneous dispersion and distribution is observed in the absence of agglutination,agglomeration,or generation of significant lumps of the *** XRD analysis showed that heat annealing induced the crystallite size favor-ing their *** obtained data confirm the synthesis of ZnO-NP and the absence of impurities associated with organic compounds in the annealed ***,those results and low-cost production pre-sent to the synthesized ZnO-NP by this biological method as a useful material in several applications.

关键词： ZnO nanoparticles green chemistry Moringa oleifera extract optical characterization structural characterization

Selective suspension of single layer graphene mechanochemically exfoliated from carbon nanofibres

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Nano Research 2014年第7期7卷 963-972页

作者： Antonio Esau del Rio-CastilloI Cesar Merino Enrique Diez-Barra Ester Vazquez departamento de Quimica Orgdnica Facultad de Ciencias y Tecnologfas Qufmicas-IRICA Universidad de Castilla-La Mancha 13071 Ciudad Real Spain Grupo Antolin ingenieria S.A. Burgos E09007 Spain

This paper presents the first report of the successful ball-milling exfoliation of graphitic filaments （GANF~ carbon nanofibres） into single layer graphene. The addition of small amounts of solvent during the milling process makes it possible to enhance the intercalation of the exfoliating agent （melamine） between the graphene layers, thus promoting exceptional exfoliation. Advantage has also been taken of the fact that the Hansen solubility parameters of graphene are different from those of carbon fibres, which allows single and few-layer graphene to be suspended in a particular solvent, thus discriminating them from poorly exfoliated carbon nanofibres.

关键词： carbon fibre graphene ball-milling exfoliation Hansen solubilityparameters

Oxidation and Coatings for Power Generation： New Super Ultra Critical Steam Turbines

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中国腐蚀与防护学报 2009年第4期29卷 318-319页

作者： F. J. PEREZ Grupo de Investigacion de ingenieria de Superficies y Materiales Nanoestructurados U. C. M. N°910627 facultad de Ciencias Quimicas Universidad Complutense de Madrid. 28040 Madrid Spain

The steels with chromium contents between 9%and 12%wt are used for power plants with advanced steam oxidation *** present good creep properties as 9%Cr steels and good oxidation resistance,at the temperatures range between 500℃～600℃.In the last years numerous investigation in development of coatings has been realized with the aim the protected them against the oxidation in order to allow operation of steam turbines at 650℃.In this study,Al-Hf protective coatings were deposited by CVD-FBR on ferritic steel HCM-12A followed by a diffusion heat treatment,have shown to be protective at 650℃under steam for at least 3000 hours of laboratory steam exposure under atmospheric *** and composition of coatings were characterized by different techniques, such as scanning electron microscopy(SEM),electron probe microanalysis,and X-ray diffraction(XRD). On the other hand,volatile species by mass spectrometry(MS) and thermogravimetric measurements (TG) during the initial stages oxidation of the P92 ferritic steel without and of Al and Al/Si coating by chemical vapour deposition in fluidized bed reactors(CVD-FBR) at 650℃in Ar+20%H_2O for 150 h were *** order to go forward to coatings design the Thermocalc code is used as base for the MSdata. TG-MS experiments were conducted in a closed steam loop in order to obtain information about the oxyhydroxides formation as reaction between coatings and *** those results the role of the different coating element could be established and optimized for the coating *** oxidation mechanism based on the TG-MS results is *** morphology/composition and structure of the oxidized samples were also studied using SEM/EDS and XRD techniques.

关键词：氧化金属腐蚀防护

Phase transitions in four-dimensional AdS black holes with a nonlinear electrodynamics source

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Communications in Theoretical Physics 2021年第12期73卷 119-128页

作者： Ramon Becar P A Gonzalez Joel Saavedra Yerko Vasquez Bin Wang departamento de Ciencias Matematicas y Fisicas Universidad Catolica de TemucoMontt 56Casilla 15-DTemucoChile facultad de ingenieria y Ciencias Universidad Diego PortalesAvenida Ejercito Libertador 441Casilla 298-VSantiagoChile instituto de Ffsica Pontificia Universidad Catolica de ValparaisoCasilla 4950ValparaisoChile departamento de Ffsica Facultad de CienciasUniversidad de La SerenaAvenida Cistemas 1200La SerenaChile Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

In this work we consider black hole solutions to Einstein’s theory coupled to a nonlinear powerlaw electromagnetic field with a fixed exponent *** study the extended phase space thermodynamics in canonical and grand canonical ensembles,where the varying cosmological constant plays the role of an effective thermodynamic *** examine thermodynamical phase transitions in such black holes and find that both first-and second-order phase transitions can occur in the canonical ensemble while,for the grand canonical ensemble,Hawking-Page and second-order phase transitions are allowed.

关键词： black hole thermodynamics nonlinear Maxwell

Fine‑tuning genomic and pedigree inbreeding rates in equine population with a deep and reliable stud book:the case of the Pura Raza Española horse

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Journal of Animal Science and Biotechnology 2023年第2期14卷 515-528页

作者： Davinia Isabel Perdomo‑Gonzalez Nora Laseca Sebastian demyda‑Peyras Mercedes Valera Isabel Cervantes Antonio Molina departamento Agronomia Escuela Tecnica Superior de Ingenieria AgromomicaUniversidad de SevillaCtra Utrera Km 141013 SevillaSpain departamento de Genetica Universidad de CordobaCordobaSpain facultad de Ciencias Veterinarias Universidad Nacional de La PlataLa PlataArgentina Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET) La PlataArgentina departamento de Produccion Animal Facultad de VeterinariaUniversidad Complutense de MadridMadridSpain.

Background:Estimating inbreeding,which is omnipresent and inevitable in livestock populations,is a primary goal for management and animal breeding especially for those interested in mitigating the negative consequences of *** coefficients have been historically estimated by using pedigree information;however,over the last decade,genome-base inbreeding coefficients have come to the forefront in this *** Pura Raza Espanola(PRE)horse is an autochthonous Spanish horse breed which has been recognised since *** total PRE population(344,718 horses)was used to estimate Classical(F),Ballou’s ancestral,Kalinowski’s ancestral,Kalinowski’s new and the ancestral history coefficient *** addition,genotypic data from a selected population of 805 PRE individuals was used to determine the individual inbreeding coefficient using SNP-by-SNP-based techniques(methods of moments-FHOM-,the diagonal elements of the genomic-FG-,and hybrid matrixes-FH-)and ROH measures(FRZ).The analyse of both pedigree and genomic based inbreeding coefficients in a large and robust population such as the PRE horse,with proven parenteral information for the last 40 years and a high degree of completeness(over 90%for the last 70 years)will allow us to understand PRE genetic variability better and the correlations between the estimations will give the data greater ***:The mean values of the pedigree-based inbreeding coefficients ranged from 0.01(F for the last 3 generations-F3-)to 0.44(ancestral history coefficient)and the mean values of genomic-based inbreeding coefficients varied from 0.05(FRZ for three generations,FH and FHOM)to 0.11(FRZ for nine generations).Significant correlations were also found between pedigree and genomic inbreeding values,which ranged between 0.58(F3 with FHOM)and 0.79(F with FRZ).In addition,the correlations between FRZ estimated for the last 20 generations and the pedigree-based inbreeding highlight the fact that fewer generations of

关键词： Genomic inbreeding Horses Pedigree inbreeding

Small-signal Model for Dual-active-bridge Converter Considering Total Elimination of Reactive Current

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Journal of Modern Power Systems and Clean Energy 2021年第2期9卷 450-458页

作者： Juan Ramon Rodriguez-Rodriguez Nadia Maria Salgado-Herrera Jacinto Torres-Jimenez Nestor Gonzalez-Cabrera David Granados-Lieberman Martin Valtierra-Rodriguez the Universidad Nacional Autonoma de Mexico Facultad de IngenieriaDepto.Energia Electri-ca.Av.Universidad 3000Col.UNAM CUCoyoacanCDMXMexico the instituto de Energias Renovables Universidad Nacional Autonoma de MexicoPriv.Xochicalco s/nCol.Centro.TemixcoMorelosMexico the instituto Tec-nologico Superior de Irapuato Carretera Irapuato-Silao km 12.5.IrapuatoGuanajuatoMexico the Universidad Autonoma de Queretaro Campus San Juan del RioRio Moctezuma 249San Juan del RioQueretaroMexico

Emerging technologies such as electric vehicles,solid-state transformers,and DC transformers are implemented using the closed-loop bi-directional dual-active-bridge(DAB)*** this context,it is necessary to have average models that provide an efficient way of tuning the proportional integral(PI)compensator parameters for large-and small-signal *** present a novel small-signal model(SSM)for DAB converter with a single closed-loop PI controller and the total elimination of reactive current(IQ=0).The method applies a modulation technique for IQ=0 and introduces a composite function in the controller while reducing the original nonlinear switching model,which allows to decrease the order of the transfer function and analyze the closed-loop *** proposed SSM is analyzed using different response time,load,and DC voltage *** simulation and experimental results demonstrate the ease of implementation and effectiveness of the proposed model with respect to other SSM techniques.

关键词： Small-signal model(SSM) dual-active-bridge(DAB)converter reactive current elimination proportional integral(PI)control

Correction to:Preface:Special Issue on Modeling,Simulation,and Optimization in Operational Research

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Journal of the Operations Research Society of China 2024年第2期12卷 548-548页

作者： Gerhard-Wilhelm Weber J.Joshua Thomas Jose Antonio Marmolejo Saucedo Ugo Fiore Igor Litvinchev Pandian Vasant Poznan University of Technology PoznanPoland Institute of Applied Mathematics Middle East Technical UniversityAnkaraTurkey UOW Malaysia KDU Penang University CollegePetaling JayaMalaysia facultad de ingenieria Universidad PanamericanaMexico CityMexico Parthenope University and at Federico II University NaplesItaly Nuevo Leon State University San Nicolas de los GarzaMexico MERLIN Research Centre Ton Duc Thang UniversityHo Chi Minh CityVietnam

Numerical Approximation of an Axisymmetric Elastoacoustic Eigenvalue Problem

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Communications in Computational Physics 2023年第10期34卷 1420-1438页

作者： J.Querales P.Venegas GIMNAP Departamento de MatematicaUniversidad del Bio-BioConcepcionChile departamento de Ciencias Exactas Facultad de IngenieriaArquitectura y DisenoUniversidad San SebastianConcepcionChile

This paper deals with the numerical approximation of a pressure/displacement formulation of the elastoacoustic vibration problem in the axisymmetric *** propose and analyze a discretization based on Lagrangian finite elements in the fluid and solid *** show that the scheme provides a correct approximation of the spectrum and prove quasi-optimal error *** report numerical results to validate the proposed methodology for elastoacoustic vibrations.

关键词： Axisymmetric problem fluid-structure interaction spectral problem finite element method

Evaluation of Bioactive Properties of α and β Wollastonite Bioceramics Soaked in a Simulated Body Fluid

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Journal of Biomaterials and Nanobiotechnology 2018年第3期9卷 263-276页

作者： Luis A.Nunez-Rodriguez Martin A.Encinas-Romero Agustin Gomez-Alvarez Jesus L.Valenzuela-Garcia Guillermo C.Tiburcio-Munive Posgrado en Ciencias de la ingenieria:ingenieria Quimica Universidad de SonoraHermosilloMexico departamento de ingenieria Quimica y metalurgia Universidad de SonoraHermosilloMexico

dense natural wollastonite bioceramics (CaSiO3) were prepared by a sintering method, varying the pressing load and sintering temperature, in order to obtain different phases of wollastonite, and different physical properties in the materials. The products were characterized by TGA-DTA, XRD, FT-IR, SEM-EDS, TEM and XPS techniques. The results indicate the presence of two polymorphic phases of wollastonite, the β-wollastonite and α-wollastonite with a transition temperature of the β phase to α phase at approximately 1250℃. These materials were soaked in a simulated body fluid (SBF) during 1, 2 and 3 weeks, to study their solubility and bioactivity. The effect of different wollastonite phases on the solubility of Ca and Si, as well as the capacity of producing layers of “newly formed apatite” on the surfaces of these materials in SBF solution were analyzed.

关键词： Bioceramics Wollastonite Simulated Body Fluid Bioactivity