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Computer Modeling in Engineering & Sciences 2018年第10期117卷 59-71页

作者： Guilherme Suguinoshita carlos henrique da silva Marco Antonio Luersen Department of Mechanical Engineering Federal University of Technology-Parana(UTFPR)Rua Deputado Heitor Alencar Furtado5000CEP 81280-340CuritibaBrazil

This paper describes a study of the effects of graphite nodule characteristics on a subsurface crack in austempered ductile iron(ADI).A representative specimen of ADI,subjected to sliding contact load,is modeled using finite elements aiming to obtain the shear stress intensity factor(KII).The parameters varied were(i)the nodule diameter(two different values were considered),(ii)the distance between the nodule and the tip of the crack and(iii)the position of the load relative to the tip of the *** results of the numerical simulations show that the smaller diameter nodule has a larger influence on KII,suggesting a higher contact fatigue crack propagation rate in the material with the smaller *** results are the opposite of those observed in experimental studies and would appear to indicate that other factors should be also considered to ensure realistic estimates of the contact fatigue strength of ADI.

关键词： Austempered ductile iron subsurface crack stress intensity factor finite element analysis graphite nodule

A Bidimensional Finite Element Study of Crack Propagation in Austempered Ductile Iron

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Computers, Materials & Continua 2023年第11期77卷 1411-1424页

作者： Gustavo von Zeska de França Roberto Luís de Assumpção Marco Antonio Luersen carlos henrique da silva Department of Mechanical Engineering Federal University of Technology–ParanáCuritiba81280-340Brazil

Austempered ductile iron(ADI)is composed of an ausferritic matrix with graphite nodules and has a wide range of applications because of its high mechanical strength,fatigue resistance,and wear resistance compared to other cast *** amount and size of the nodules can be controlled by the chemical composition and austenitizing *** the nodules have lower stiffness than the matrix and can act as stress concentrators,they influence crack ***,the crack propagation mechanism in ADI is not yet fully *** this study,we describe a numerical investigation of crack propagation in ADIs subjected to cyclic *** numerical model used to calculate the stress intensity factors in the material under the given conditions is built with the aid of Abaqus commercial finite element *** crack propagation routine,which is based on the Paris law,is implemented in *** results of the simulation show that the presence of a nodule generates a shear load on the crack ***,even under uniaxial tensile loading,the presence of the nodule yields a non-zero stress intensity factor in mode II,resulting in a deviation in the crack propagation *** is the primary factor responsible for changing the crack propagation direction towards the *** the parameters,for example,increasing the nodule size or decreasing the distance between the nodule and crack tip,can intensify this *** simulations comparing two different ADIs with the same graphite fraction area,the crack in the material with more nodules reaches another nodule in a shorter propagation time(or shorter number of cycles).This suggests that the high fatigue resistance observed in ADIs may be correlated with the number of nodules intercepted by a crack and the additional energy required to nucleate new *** summary,these findings contribute to a better understanding of crack propagation in ADIs,provide insights into the relationship between the presence

关键词： Austempered ductile iron(ADI) fatigue crack propagation graphite nodule

Supercritical fluid technology as a sustainable alternative method for textile dyeing:An approach on waste,energy,and CO_(2)emission reduction

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Journal of Environmental Sciences 2024年第6期140卷 123-145页

作者： carlos Rafael silva de Oliveira Patrícia Viera de Oliveira Leandro Pellenz Catia Rosana Lange de Aguiar Afonso henrique da silva Júnior Federal University of Santa Catarina Textile Engineering Department2514 João Pessoa St.BlumenauSC89036-004Brazil Federal University of Santa Catarina Chemical Engineering DepartmentS/n Biotério Central St.FlorianópolisSC88040-900Brazil

The clothing industry is considered one of the most polluting industries on the planet due to the high consumption of water,energy,chemicals/dyes,and high generation of solid waste and *** with environmental concerns,the textile ennoblement sector is the most critical of the textile production chain,especially the traditional dyeing *** an alternative to current problems,dyeing with supercritical CO_(2)(scCO_(2))has been presented as a clean and efficient process for a sustainable textile *** fluid dyeing(SFD)has shown a growing interest due to its significant impact on environmental preservation and social,economic,and financial *** main SFD benefits include economy and reuse of non-adsorbed dyes;reduction of process time and energy expenditure;capture of atmospheric CO_(2)(greenhouse gas);use and recycling of CO_(2)in SFD;generation of carbon credits;water-free process;effluent-free process;reduction of CO_(2)emission and auxiliary *** being still a non-scalable and evolving technology,SFD is the future of *** review presented a comprehensive overview of the environmental impacts caused by traditional processes and confronted the advantages of *** SFD technique was introduced,along with its latest advances and future *** and environmental gains were also discussed.

关键词： Textile industry Supercritical dyeing Sustainable processes Water free dyeing Energy saving Cleaner production

Molecular and cellular mechanisms of neuroprotection by oligopeptides from snake venoms

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BIOCELL 2024年第6期48卷 897-904页

作者： carlos ALBERTO-silva BRENda RUFINO da silva Natural and Humanities Sciences Center Experimental Morphophysiology LaboratoryFederal University of ABC(UFABC)São Bernardo do CampoSão PauloBrazil

Venom snake-derived peptides have multiple biochemical,pharmacological,and toxicological proﬁles,allowing for the discovery of new medicinal products and therapeutic *** review speciﬁcally examines the fundamental elements of neuroprotection offered by different oligopeptides derived from snake *** also includes a brief evaluation of short peptides that are being considered as potential therapeutic ***-rich peptides and tryptophyllin family peptides isolated from the crude venom of Viperidae family snakes,speciﬁcally Bothrops atrox,Bothrops jararaca,and Bothrops moojeni,have been shown to have pro-survival properties,the ability to reduce oxidative stress,and the ability to promote cell viability and mitochondrial *** signiﬁcant mechanisms are related to the neuroprotection mediated by snake venom oligopeptides:(1)Activation of the L-arginine metabolite pathway,such as polyamines from ornithine metabolism,which reduces N-methyl-D-aspartate(NMda)-type glutamate receptor activity;(2)Enhancement of cell viability by activating the nerve growth factor-signaling pathway;and(3)Activation of the Muscarinic acetylcholine receptor subtype M1(mAChR-M1).These small peptides show promise as neuroprotective agents against a variety of neurodegenerative disorders.

关键词： Neuroprotective peptides Neurodegenerative disease Oxidative stress Reactive oxygen species Biopeptides

Perpendicularly Self-Oriented and Shape-Controlled L10-FePt Nanorods Directly Synthesized by a Temperature-Modulated Process

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Nano Research 2011年第7期4卷 666-674页

作者： Tiago Luis da silva Laudemir carlos Varanda Colloidal Materials Group Instituto de Quimica de Sao Carlos Universidade de Sao Paulo--USP Sao Carlos PO Box 780 13566-590 Brazil

The synthesis and self-assembly of tetragonal phase-containing L10-Fe55Pt45 nanorods with high coercive field is described. The experimental procedure resulted in a tetragonal/cubic phase ratio close to 1：1 for the as-synthesized nanoparticles. Using different surfactant/solvent proportions in the process allowed control of particle morphology from nanospheres to nanowires. Monodisperse nanorods with lengths of 60 ＋ 5 nm and diameters of 2-3 nm were self-assembled in a perpendicular oriented array onto a substrate surface using hexadecylamine as organic spacer. Magnetic alignment and properties assigned, respectively, to the shape anisotropy and the tetragonal phase suggest that the self-assembled materials are a strong candidate to solve the problem of random magnetic alignment observed in FePt nanospheres leading to applications in ultrahigh magnetic recording （UHMR） systems capable of achieving a performance of the order of terabits/in2.

关键词： Magnetic materials data storage FePt nanorods self-assembl~ perpendicular magnetic alignment

Recovery of rare-earth metals from aqueous solutions by bio/adsorption using non-conventional materials:a review with recent studies and promising approaches in column applications

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Journal of Rare Earths 2020年第4期38卷 339-355页

作者： Talles Barcelos da Costa Meuris Gurgel carlos da silva Melissa Gurgel Adeodato Vieira University of Campinas School of Chemical EngineeringAlbert Einstein Avenue50013083e852 CampinasBrazil

The recovery of rare-earth metals(REMs)is of great economic and environmental interest,because of their high market prices and various industrial ***,with the increasing demand for high-purity rare-earth compounds,the separation and purification of these elements have gained considerable *** bio/adsorption process has been considered an alternative to recover these elements,by its simplicity,low cost and efficiency for recovery of REMs at low *** review article presents the recent progress regarding REM bio/adsorption published literature in batch system by different non-conventional bio/adsorbents,as well as a critical analysis of the technological challenges to be faced and future *** this purpose,the best application model(isotherm,kinetics),thermodynamic quantities and selection of eluents for desorption studies are also ***,in this review,the application of different bio/adsorbent materials were reviewed extensively in terms of the removal and recovery of REMs in continuous fixed-bed adsorption and regeneration ***,future aspects in bio/adsorption research and prospects for commercial applications were discussed.

关键词： Rare-earth metals Bio/adsorbents Adsorption kinetics Isotherm Batch desorption Continuous fixed-bed adsorption

Global epidemiology of sexually transmitted diseases

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Asian Journal of Andrology 2008年第1期10卷 110-114页

作者： carlos T. da Ros Caio da silva Schmitt Urology Department Mae de Deus Hospital Porto Alegre RS 90450180 Brazil

Sexually transmitted diseases （STDs） are among the first ten causes of unpleasant diseases in young adult males in developing countries and the second major cause of unpleasant diseases in young adult women. Adolescents and young adults （15-24 years old） make up only 25% of the sexually active population, but represent almost 50% of all new acquired STDs. In general, STDs are epidemics and present an enormous health and economic consequences. An adequate screening for STDs should be done on a routine basis in every part of the world. Many STDs are asymptomatic and therefore can difficult to control. The purpose of reporting of STDs is to ensure that persons who are infected will be quickly diagnosed and appropriately treated to control the spread of infection and also so that partners are notified, tested and appropriately treated. It is estimated that reported cases of STDs represent only 50%-80% of reportable STD infections in the United States, reflecting limited screening and low disease reporting. High-risk sexual behavior is a highly contributive factor of this process as it often leads to teenage pregnancies and HIV/AIDS. One possible explanation for this behavior is that people do not have enough information about the transmission of STDs or ignore the precautions required for safe sex. Approximately 60% of new HIV infections worldwide occur in young people. The frequency of high-risk behaviors among youths may also be influenced by opportunity to engage in them, particularly the amount of time that they are unsupervised by adults. However, in diagnosing and treating these patients, we can effectively prevent the spread of HIV/AIDS. Individuals infected with STDs are 5-10 times more likely than uninfected individuals to acquire or transmit HIV through sexual contact. The breaking of the genital tract lining or skin creates a portal of entry for HIV and, hence, HIV-infected individuals with other STDs are more likely to shed HIV in their genital secretions. T

关键词： sexually transmitted diseases safe sex condom young people

Pathogenesis and clinical management of arboviral diseases

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World Journal of Virology 2025年第1期14卷 9-50页

作者： Victoria Cenci Dietrich Juan Marcos Caram Costa Marina Maria Gomes Leite Oliveira carlos Eduardo Oliveira Aguiar Luis Guilherme de Oliveira silva Marcel silva Luz Fabian Fellipe Bueno Lemos Fabrício Freire de Melo Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil

Arboviral diseases are viral infections transmitted to humans through the bites of arthropods,such as mosquitoes,often causing a variety of pathologies associated with high levels of morbidity and *** the past decades,these infections have proven to be a significant challenge to health systems worldwide,particularly following the considerable geographic expansion of the dengue virus(DENV)and its most recent outbreak in Latin America as well as the difficult-tocontrol outbreaks of yellow fever virus(YFV),chikungunya virus(CHIKV),and Zika virus(ZIKV),leaving behind a substantial portion of the population with complications related to these ***,the world is experiencing a period of intense globalization,which,combined with global warming,directly contributes to wider dissemination of arbovirus vectors across the ***,all continents remain on high alert for potential new ***,this review aims to provide a comprehensive understanding of the pathogenesis of the four main arboviruses today(DENV,ZIKV,YFV,and CHIKV)discussing their viral characteristics,immune responses,and mechanisms of viral evasion,as well as important clinical aspects for patient *** includes associated symptoms,laboratory tests,treatments,existing or developing vaccines and the main associated complications,thus integrating a broad historical,scientific and clinical approach.

关键词： Arboviruses Arbovirus infections Dengue Zika virus Yellow fever Chikungunya virus Clinical diagnosis Pathogenesis Flavivirus Togaviridae infections

Microstructure and mechanical behavior of similar butt-joints of ZK60 and ZK60-1.5RE magnesium alloys produced by linear friction stir welding

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Journal of Magnesium and Alloys 2021年第5期9卷 1802-1817页

作者： Erenilton Pereira da silva Ricardo henrique Buzolin Ulises Alfaro Guillermo Requena Haroldo Calvalcanti Pinto Institute of Engineering Science and Technology(IECT)Federal University of Vales do Jequitinhonha e Mucuri(UFVJM)JanaúbaMGBrazil Department of Materials Engineering São Carlos School of Engineering(EESC)University of São Paulo(USP)São Carlos-SP CEP 13563-120Brazil Christian Doppler Laboratory for Design of High-Performance Alloys by Thermomechanical Processing Kopernikusgasse 24Graz 8010Austria Institute of Materials Science Joining and Forming at Graz University of Technology opernikusgasse 24/IGraz 8010Austria German Aerospace Center(DLR)Institute of Materials Research Linder HöheCologne 51147Germany RWTH Aachen University Metallic Structures and Materials Systems for Aerospace EngineeringD-52062 AachenGermany.

The microstructure and mechanical properties of butt-joints produced by linear friction stir welding of similar plates of as-cast ZK60 and modified ZK60 with 1.5 wt.%RE(ZK60-1.5 RE)are *** thermomechanical affected zone is investigated in both advancing and retrieving sides,and the microstructure is compared to the base metal and the stirred *** backscattered diffraction measurements provide the average microstructural features of the transformed *** mechanical properties are assessed using hardness,tensile testing,and surface residual stress measured using X-ray *** torque and heat input are obtained for the ZK60-1.5 RE compared to the *** thermomechanical affected zone is notably larger for the ZK60 compared to the ZK60-1.5 RE.A gradient microstructure is formed in thermomechanical affected zones where deformed grains are progressively more recrystallised towards the stirred *** is no visible interface between the thermomechanical affected zone and the stirred zone.A fine and partially recrystallised microstructure is formed in the stirred *** retrieving side of the ZK60-1.5 RE has a slightly more refined microstructure compared to the other investigated *** measured with increment in the maximum intensity of the(0001)increases towards to stirred *** formed microstructure is correlated with the role of twinning,recovery,static,and dynamic recrystallisation that can occur during friction stir *** and grains with large misorientation spread are more pronounced in the thermomechanical affected zone and regions towards the base *** low angle grain boundaries are observed towards the stirred *** refined recrystallised grains decorating the grain in the thermomechanical affected zone,a mosaic-like of low and high angle grain boundaries are observed in the stirred *** joints have comparable surface residual *** friction stir welding improved th

关键词： ZK60 Mischmetal FSW Recrystallization Microstructure Thermomechanical

Application of advanced oxidation processes for removing salicylic acid from synthetic wastewaters

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Chinese Chemical Letters 2010年第1期21卷 101-104页

作者： Djalma Ribeiro da silva carlos A.Martinez-Huítle Universidade Federal do Rio Grande do Norte CCET-Departamento de QuimicaLagoa Nova-CEP 59.072-970 Brazil Universidade Federal do Rio Grande do Norte CCET-Departamento de QuimicaLagoa Nova-CEP 59.072.970 Brazil University of Milan Department of ChemistryCeloria 220133 MilanItaly

In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale ***-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of *** the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO *** study showed that the FP was the most effective process under aci...

关键词： Advanced oxidation processes Salicylic acid(SA) Anodic oxidation Ta/BDD Electrocatalytic activity