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A Finite Element Study of the Influence of Graphite Nodule Characteristics on a Subsurface Crack in a Ductile Cast Iron Matrix under a Contact Load

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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

Enzymatic Conversion of Sugarcane Lignocellulosic Biomass as a Platform for the Production of Ethanol,Enzymes and Nanocellulose

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Journal of Renewable Materials 2018年第2期6卷 203-216页

作者： Cristiane S.Farinas Jose Manoel Marconcini luiz henrique C.Mattoso Nanotechnology National Laboratory for Agriculture(LNNA) Embrapa InstrumentationRua XV de Novembro 145213561-206São CarlosSPBrazil

The conversion of sugarcane lignocellulosic biomass into fuels,chemicals and high-value materials using the biochemical pathway is considered the most sustainable alternative for the implementation of future ***,the first large-scale cellulosic ethanol plants that have started operating worldwide apply the enzymatic hydrolysis process to convert biomass into simple sugars that are fermented to ethanol by ***,several technological challenges still need to be addressed in order to obtain commercially competitive *** review describes current challenges and perspectives regarding the enzymatic hydrolysis step for processing sugarcane lignocellulosic biomass within the *** developments in terms of process configuration strategies and opportunities for the implementation of a sugarcane biorefinery,in which the production of ethanol is integrated into the production of high-value products such as enzymes and nanocellulose,are discussed in view of the demands of the current bioeconomy.

关键词： Enzymatic hydrolysis bioethanol sugarcane nanocellulose biorefinery

Fractionation of rare earth and other trace elements in crabs,Ucides cordatus,from a subtropical mangrove affected by fertilizer industry

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Journal of Environmental Sciences 2017年第4期29卷 69-76页

作者： Alice Bosco-Santos Wanilson luiz-silva Emmanoel Vieira da silva-Filho Monique Dias Corrêa de Souza Elton luiz Dantas Margareth Sugano Navarro State University of Campinas (UNICAMP) Institute of Geosciences Department of Geology and Natural Resources Campinas Sao Paulo 13083870 Brazil . Fluminense Federal University (UFF) Institute of Chemistry Department of Geochemistry Niteroi Rio de Janeiro 24900970 Brazil University of Brasília(UnB) Institute of Geosciences Department of Geology Brasflia Distrito Federal 70910900 Brazil

Fractionation of rare earth elements（REE） and other trace metal concentrations（Th, U, Cd,Cr, Cu, Ni, Pb, and Zn） between mangrove sediments and claw muscles and shells of male crabs（Ucides cordatus） from a subtropical estuary highly impacted by fertilizer industry activities was investigated. This is the first record of REE distribution in these organisms,and the results showed higher accumulations of these metals, U and Th in shells, probably related to the replacement of Ca during molting. Contents of Cd, Cr and Ni were similar in both tissues, but Cu, Zn and Pb were mostly accumulated in the claw muscle with concentrations above those considered safe for human consumption according to the Brazilian legislation. REE fractionation was different in the analyzed tissues being softer in the shells. The results provided evidences that the water absorbed during molting controls the chemistry of REE in shells. In contrast, the chemistry of REE in the claw muscle, in which was observed preferential absorption of light REE, is controlled by diet. REE fractionation obtained for the claw muscles was closely correlated to the observed in the contaminated substrate and in materials related to the production of phosphate fertilizers（contamination source）, which supports their transference to this Ucides cordatus tissue without fractionation by the ingestion of sediments. Our results showed the potential use of crab tissues for monitoring REE and trace element sources in mangrove areas, with claw muscle exhibiting the contaminant source fingerprint.

关键词： Rare earth elements Trace metals Fertilizer contamination Crabs

Lafoensia pacari alleviates intestinal damage by modulating cyclooxygenase-2:In silico and in vivo evaluation in a colitis model

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World Journal of Gastroenterology 2023年第17期29卷 2628-2641页

作者： Gabrielle Caroline Peiter Thayene Kamyli Moesch Queiroz Edson luiz Michalkiewicz Jr Raphael henrique Chappuis Jennefer Sousa Luz luiz henrique Casagrande Piovezani Cleison Ferreira silva Matheus Nozomi Tsutumi Augusto Fernandes Chaves Rafael Messias luiz Cinthia Façanha Wendel Ana Carla Zarpelon-Schutz Kádima Nayara Teixeira Programa Multicêntrico de Pós-graduação em Biquímica e Biologia Molecular-Setor Palotina Universidade Federal do ParanáPalotina 85.950-000ParanáBrazil Programa de Pós-graduação em Biotecnologia-Setor Palotina Universidade Federal do ParanáPalotina 85.950-000ParanáBrazil Campus Toledo Universidade Federal do ParanáToledo 85.919-899ParanáBrazil

BACKGROUND Inflammatory bowel diseases(IBD)are a worldwide health problem and mainly affect young people,consequently affecting the *** treatments are often associated with side effects,and new therapeutic options are *** centuries,plants have represented important substrates in the field of drug *** pacari(***)is a plant whose pharmaceutical potential has been described,and may have biological activity relevant to the treatment of IBD *** To investigate the activity of keto-alcoholic extracts of *** with respect to ameliorating the inflammatory and nociceptive symptoms of acute experimental colitis in *** Keto-alcoholic extracts of *** leaves and bark were administered to male andfemale Swiss mice weighing 25 g to 30 g(n=8 male mice and n=8 female mice).The effect of these extracts was observed in an acetic acid-induced acute experimental model of colitis with regard to antinociception/analgesia and inflammatory tissue *** macroscopic indices included the Wallace score and the colon weight obtained using a precision *** hyperalgesia was determined using an electronic *** related to overt pain was determined by quantifying the number of writhing instances within 20 min of administration of acetic *** docking was performed using human and murine cyclooxygenase-2(COX-2)with 3 flavonoids(ellagic acid,kaempferol,and quercetin)on the AutoDock Vina *** of variance followed by Tukey’s posttest was used with P<0.05 indicating *** In this murine model of colitis,administration of extracts from *** ameliorated acetic acidinduced writhing and colitis-associated inflammatory *** improvements may be attributable to the reduction in edema,inflammation(e.g.,ulcers,hyperemia,and bowel wall damage),and the intensity of abdominal *** keto-alcoholic extracts of *** leaves and bark administered at a

关键词： Antinociceptive activity Anti-inflammatory activity Cyclooxygenase-2 Flavonoids Inflammatory bowel disease Lafoensia pacari

Dendritic Growth, Eutectic Features and Their Effects on Hardness of a Ternary Sn–Zn–Cu Solder Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第6期30卷 528-540页

作者： Bismarck luiz silva Rodrigo Valenzuela Reyes Amauri Garcia JoséEduardo Spinelli Department of Materials Engineering Federal University of Rio Grande do Norte-UFRNNatalRN 59078-970Brazil Department of Materials Engineering Federal University of Sao Carlos-UFSCarSao CarlosSP 13565-905Brazil Department of Manufacturing and Materials Engineering University of CampinasUNICAMPCampinasSP 13083-860Brazil

The present investigation is based on the results of a directionally solidified （DS） Sn-9 wt%Zn-2 wt%Cu alloy, including primary/secondary/tertiary dendrite arm spacings of the Sn-rich matrix, the morphologies of the eutectic mixture and the corresponding interphase spacing, the nature and proportion of the Cu-Zn intermetallic compound （IMC）. The main purpose is to establish interrelations of these microstructure features with experimental solidification thermal parameters, such as cooling rates and growth rates （v）, macrosegregation and hardness. Such interrelations are interesting for both industry and academy since they represent a tool permitting the preprogramming of final properties based on the design of the microstructure. In the case of Sn-Zn-Cu alloys, hardly anything is known about the combined effects of the length scale of the microstructure and fraction and distribution of the primary IMC on hardness. The alloy microstructure is composed of a β-Sn dendritic region, surrounded by a eutectic mixture of α-Zn and β-Sn phases and the γ-Cu5Zn8 IMC. The eutectic interphase spacing varies in the range 1.2-3.6 μm, with the α-Zn phase having a globular morphology for ν 〉 0.5 mm/s and a needle-like morphology for ν 〈 0.3 mm/s. A modified Hall-Petch-type experimental expression relating hardness to the interphase spacing is proposed.

关键词： Sn-Zn-Cu solder alloy Solidification Microstructure Eutectic morphology Hardness

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

Adipose tissue,systematic inflammation,and neurodegenerative diseases

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Neural Regeneration Research 2023年第1期18卷 38-46页

作者： Ana Paula de A.Boleti Pedro henrique de O.Cardoso Breno Emanuel F.Frihling Patrícia Souza e silva luiz Filipe R.Nde Moraes Ludovico Migliolo S-Inova Biotech Programa de Pós-Graduação em BiotecnologiaUniversidade Católica Dom BoscoCampo GrandeMSBrazil Programa de Pós-Graduação em Biologia Celular e Molecular Programa de Pós-Graduação em BioquímicaUniversidade Federal do Rio Grande do NorteNatalBrazil

Obesity is associated with several diseases,including mental *** tissue is distributed around the internal organs,acting in the regulation of metabolism by storing and releasing fatty acids and adipokine in the *** nutritional intake results in hypertrophy and proliferation of adipocytes,leading to local hypoxia in adipose tissue and changes in these adipokine *** leads to the recruitment of immune cells to adipose tissue and the release of pro-inflammatory *** presence of high levels of free fatty acids and inflammatory molecules interfere with intracellular insulin signaling,which can generate a neuroinflammatory *** this review,we provide an up-to-date discussion of how excessive obesity can lead to possible cognitive *** also address the idea that obesity-associated systemic inflammation leads to neuroinflammation in the brain,particularly the hypothalamus and hippocampus,and that this is partially responsible for these negative cognitive *** addition,we discuss some clinical models and animal studies for obesity and clarify the mechanism of action of anti-obesity drugs in the central nervous system.

关键词： adiposity anti-obesity drugs hypothalamic inflammation metabolic disease neurodegenerative disease neuroinflammation

A methodology for coffee price forecasting based on extreme learning machines

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Information Processing in Agriculture 2022年第4期9卷 556-565页

作者： Carolina Deina Matheus henrique do Amaral Prates Carlos henrique Rodrigues Alves Marcella Scoczynski Ribeiro Martins Flavio Trojan Sergio luiz Stevan Jr Hugo Valadares Siqueira Department of Production Engineering Federal University of Rio Grande do Sul90.035-190Brazil Department of Electronics Federal University of TechnologyParana 84017-220Brazil Graduate Program in Production Engineering Federal University of TechnologyParana 84017-220Brazil

This work introduces a methodology to estimate coffee prices based on the use of Extreme Learning *** process is initiated by identifying the presence of nonstationary components,like seasonality and *** components are withdrawn if they are ***,the temporal lags are selected based on the response of the Partial Autocorre-lation Function *** predictors,we address the following models:Exponential Smooth-ing(ES),Autoregressive(AR)and Autoregressive Integrated and Moving Average(ARIMA)models,Multilayer Perceptron(MLP)and Extreme Learning Machines(ELMs)neural *** computational results based on three error metrics and two coffee types(Ara-bica and Robusta)showed that the neural networks,especially the ELM,can reach higher performance levels than the other *** methodology,which presents preprocess-ing stages,lag selection,and use of ELM,is a novelty that contributes to the coffee prices forecasting field.

关键词： Coffee price forecasting Linear models Artificial neural networks Computational intelligence

Traits uncover quasi-neutral community assembly in a coastal heath vegetation

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Journal of Plant Ecology 2019年第4期12卷 703-712页

作者： Joséluiz Alves silva Alexandre Fadigas Souza Louis Stephen Santiago Programa de Pós-Graduação em Ecologia Departamento de EcologiaUniversidade Federal do Rio Grande do NorteNatal 59078-970Brazil Departamento de Ecologia Universidade Federal do Rio Grande do NorteNatal 59078-970Brazil Department of Botany and Plant Sciences University of California2150 Batchelor HallRiversideCA 92521USA Smithsonian Tropical Research Institute BalboaAncónPanamáRepublic of Panamá

Aims Trait-based approaches are increasingly being used in ecology due to their potential to explain and predict community structure and dynamic regardless of species ***,we asked whether coastal heath vegetation established in stressful habitats could be assembled by quasi-neutral mechanisms based on functional trait *** are organized through quasi-neutral dynamics if abiotic gradients and/or species interactions impose sorting on functional traits and species performances,but not on species phylogenetic relatedness and *** The study was conducted in a coastal area containing tall dunes near the sea,and relatively flat areas punctuated by short palaeodunes further inland,Northeastern South *** evaluated 10 traits of the 21 most abundant species,as well as eight abiotic variables in 70 plots(25 m^(2))established in dune tops,valleys,flat and steep *** effect of environmental filter was tested by linear mixed models(LMM)between each community-weighted mean(CWM)trait and the abiotic variables,and by two indices of environmental filtering based on intra-and interspecific-trait vari-ability relative to null *** evaluate the effect of species inter-actions,we used an index of niche overlap relative to null models,and LMMs between this index and the species richness of *** Findings The environmental filtering index did not deviate from null expect-ations for any *** that included individual variability per-formed similarly to models that used species mean ***,the explicit consideration of environmental gradients by CWM ana-lyses revealed functional patterns that would remain undetected if trait distribution was analyzed *** addition,intraspecific vari-ation in the stem length was an important driver of species diversity as suggested by the relationship between species richness and the niche overlap *** on the occurrence and phylogenetic re-latedness o

关键词： Restinga heath vegetation harsh environment stress-tolerant species response traits