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Early Failure Detection in Power Transformers

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Journal of Power and Energy Engineering 2013年第5期1卷 30-40页

作者： luiz eduardo borges da silva Erik Leandro Bonaldi Levy Ely de Lacerda de Oliveira Germano Lambert-Torres Giscard F. C. Veloso Ismael Noronha Felipe dos Santos Moreira José Nielze Caminha Itajuba Federal University Itajuba Brazil 2PS Solutions Itajuba Brazil 3Termopernambuco Thermal Power Plant Recife Brazil.

This paper presents equipment for early detection of failures in the insulation of power transformers, checking existing partial discharges inside. The equipment involves hardware, control and signal acquisition software, and signal analysis software. This equipment has a set of algorithms that were made with intelligent extraction techniques and interpretation of data. The degradation diagnosis of the equipment insulation is based on digital signal processing algorithms for extraction of features and also in artificial intelligence algorithms that allies a mining involving all the data linked to the equipment throughout its operating life can make an assessment of the operating conditions of the equipment and suggest interventions and provide an estimated time so that they have to be made.

关键词： Transformers Measuring System Signal Processing Partial Discharges Predictive Maintenance

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

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

Radiographic and tomographic description of marlin sucker Remora osteochir, Pisces: Echeneidae—preliminary data of one specimen

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Marine Life Science & Technology 2020年第3期2卷 246-251页

作者： Andréluiz Veiga Conrado Renata Stecca lunes Carlos eduardo Malavasi Bruno Aline Tiemi Shiraishi Rocha JoséRoberto Machado Cunha da silva Laboratory of Evolutive Histophysiology Department of Cell and Developmental BiologyInstitute of Biomedical SciencesUniversity of Sao PauloAvenida ProfLineu Prestes1524Cidade UniversitariaSao Paulo 05508-000Brazil Laboratory of Immunological Techniques Applied to Morphophysiology School of Veterinary Medicine and Animal ScienceDepartment of SurgeryUniversity of Sao PauloAvenida Prof.Di.Orlando Marques de Paiva87.Cidade UniversitariaSao Paulo 05508-270Brazil

Remoras are commensal fish of various marine species,such as sharks,swordfishes,turtles,dolphins,manta rays and *** specimen of marlin sucker Remora osteochir was evaluated using computed tomography for skeletal digital reconstruction,digital radiology for general evaluation and bone counting,and the double contrast technique to distinguish coelomic *** radiographic images,it was possible to observe otoliths in the center of the neurocranium,to count 27 vertebrae,nine pairs of ribs,and to detect the presence of the hipural and epural bones near of the caudal *** double contrast images,it was possible to visualize the swim bladder,gills,heart,liver,stomach and *** the tomographic images and reconstructions,it was possible to identify the intercalar bones of the cephalic disc;the spine with vertebral bodies composed of neural arches and ventral ribs;and the pectoral girdle formed by posttemporal,cleithrum and scapulocoracoid *** was concluded that digital radiology and computed tomography were able to describe anatomical structures of marlin sucker *** without the need for dissection.

关键词： Teleost fish Double contrast Computed tomography Digital radiology Skeleton

Evaluation of physicochemical properties as supporting information on quality control of raw materials and veterinary pharmaceutical formulations

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Journal of Pharmaceutical Analysis 2018年第3期8卷 168-175页

作者： Sara da silva Anacleto Marcella Matos Cordeiro borges Hanna Leijoto de Oliveira Andressa Reis Vicente eduardo Costa de Figueiredo Marcone Augusto Leal de Oliveira Barbara Juliana Pinheiro borges Marcelo Antonio de Oliveira Warley de Souza borges Keyller Bastos borges Departamento de Ciencias Naturals Universidade Federal de Sao Joao del-Rei Campus Dom Bosco Praca Dora Helvecio 74 Fabricas 36301-160 Sao Joao del-Rei Minas Gerais Brazil Departamento de Quimica Universidade Federal do Espirito Santo Avenida Fernando Ferrari 514 Goiabeiras 29075-910 Vitdria Espirito Santo Brazil Laboratorio de Analise de Toxicantes e Farmacos Faculdade de Ciencias Farmaceuticas Universidade Federal de Alfenas Rua Gabriel Monteiro da Silva 700 Centro 37130-000 Alfenas Minas Gerais Brazil Departamento de Quimica Universidade Federal de Juiz de Fora Rua Jose Lourenco Kelmer s/n 36036-330 Juiz de Fora Minas Gerais Brazil Centro de Ciencias da Saude Universidade Federal do Espirito Santo Avenida Marechal Campos 1468 Maruipe 29.043-900 Vitori Espirito Santo Brazil Centro Universitario Norte do Espirito Santo Universidade Federal do Espirito Santo Br 101 Norte Km 67 Sao Mateus Espirito Santo Brazil

This study aimed to show that the physicochemical proprieties obtained by Fourier transform infrared spectroscopy （FTIR）, thermogravimetry （TG）, and scanning electronic microscopy （SEM） can be useful tools for evaluating the quality of active pharmaceutical ingredients （APIs） and pharmaceutical products. In addition, a simple, sensitive, and efficient method employing HPLC-daD was developed for simulta- neous determination of lidocaine （LID）, ciprofloxacin （CFX） and enrofloxacin （EFX） in raw materials and in veterinary pharmaceutical formulations. Compounds were separated using a Gemini Cm （250 mm×4.6 mm, 5μm） Phenomenex column, at a temperature of 25℃, with a mobile phase containing 10 mM of phosphoric acid （pH 3.29）： acetonitrile （85.7：14.3, v/v） and a flow rate of 1.5 mL/min. Physicochemical characterization by TG, FTIR, and SEM of raw materials of LID, CFX, and EFX provided information useful for the evaluation, differentiation, and qualification of raw materials. Finally, the HPLC method was proved to be useful for evaluation of raw material and finished products, besides satisfying the need for an analytical method that allows simultaneous determination of EFX, CFX, and LID, which can also be extended to other matrices and applications.

关键词： HPLC Physicochemical characterization Quality control Veterinary pharmaceutical formulation Raw material

Assembly structures of coastal woody species of eastern South America:Patterns and drivers

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Plant Diversity 2024年第5期46卷 611-620页

作者： eduardo Vinícius da silva Oliveira Myrna Friederichs Landim Sidney F.Gouveia Graduate Program in Ecology and Conservation Federal University of SergipeSão CristovãoSergipeBrazil National Institute of Science and Technology Ecology Evolution and Conservation of Biodiversity(INCT-EECBio)GoiâniaGoiasBrazil Department of Biology Federal University of SergipeSão CristóvãoSergipeBrazil Department of Ecology Federal University of SergipeSão CristóvãoSergipeBrazil

Tropical regions have provided new insights into how ecological communities are *** dry coastal communities,water stress has been hypothesized to determine plant assembly structure by favoring preadapted lineages from neighboring ecosystems,consistent with functional ***,it is unclear whether this hypothesis is sufficient to explain how coastal communities in tropical ecosystems are ***,we test whether water stress or other factors drive community assembly in woody plant communities across the coastal zone of Brazil,a tropical *** characterized functional and phylogenetic structures of these communities and determined the underlying environmental factors(e.g.,water stress,historical climate stability,edaphic constraints,and habitat heterogeneity)that drive their community *** of coastal woody species show geographically varied patterns,including stochastic arrangements,clustering,and overdispersion of species relative to their traits and phylogenetic *** complexity,water vapor pressure,and soil nutrient availability best explained the gradient in the functional *** deficit,water vapor pressure,and soil organic carbon were the best predictors of variation in phylogenetic *** results support the water-stress conservatism hypothesis on functional and phylogenetic structure,as well as the effect of habitat heterogeneity on functional structure and edaphic constraints on functional and phylogenetic *** effects are associated with increased phenotypic and phylogenetic divergence of woody plant assemblages,which is likely mediated by abiotic filtering and niche opportunities,suggesting a complex pattern of ecological assembly.

关键词： Brazil Completeness Clustering Restinga vegetation Water constraints

How far have we come?Review of main public policies to reduce landslide impacts in Brazil

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Journal of Mountain Science 2024年第9期21卷 2891-2904页

作者： Bianca Carvalho VIEIRA Tiago damas MARTINS Telma Mendes da silva Joséeduardo BONINI Department of Geography University of São PauloAvenida Professor Lineu Prestes 05508-000Brazil Cities Institute Federal University of São PauloAvenida Jacu-Pêssego 08260-001Brazil Department of Geography Federal University of Rio de JaneiroAvenida Athos da Silveira Ramos 21941-916Brazil

During the rainy season in Brazil,landslides can have catastrophic consequences,including loss of life,damage to urban infrastructure and significant economic ***,more than eight million people in Brazil live in disaster-prone *** objective of this article is to present a chronological review of the principal policies and programmes at the national,state,and municipal levels,with an emphasis on their key actions aimed at mitigating the impact of disasters related to natural hazards,particularly *** analysis was based on official records of public policies from the national,state,and municipal *** results show that several initiatives were initially developed at the local and regional ***,it was not until the late 1980s that a comprehensive organisation of civil protection at the national level emerged as a response *** is possible to highlight three phases(understanding,coexistence,and prevention)of institutional action focused on risk management in the face of *** the growing knowledge of risk scenarios,disasters continue to occur in Brazil on an annual basis,revealing several obstacles to reducing their impact,particularly given the social and economic disparities between Brazilian regions and the applicability of public policies that must overcome the limitations of each municipality.

关键词： Disasters Risk Mitigation Prevention Legislation Civil Defense Natural Hazards

Integrating geochemical(surface waters, stream sediments)and biological(diatoms) approaches to assess AMD environmental impact in a pyritic mining area： Aljustrel(Alentejo, Portugal)

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Journal of Environmental Sciences 2016年第4期28卷 215-226页

作者： Ana Teresa Luís Nuno Duraes SaloméFernandes Pinheiro de Almeida eduardo Ferreira da silva University of Aveiro Department of GeosciencesGeoBioTec--GeobiosciencesGeotechnologies and Geoengineering Research CenterCampus de Santiago3810-193 AveiroPortugal University of Aveiro Department of BiologyGeoBioTec--GeobiosciencesGeotechnologies and Geoengineering Research CenterCampus de Santiago3810-193 AveiroPortugal Centro de Ciencias do Mar CCMARUniversidade do AlgarveCampus de Gambelas8005-139 FaroPortugal

Aljustrel mines were classified as having high environmental hazard due to their large tailings volume and high metal concentrations in waters and *** assess acid mine drainage impacted systems whose environmental conditions change quickly,the use of biological indicators with short generation time such as diatoms is *** study combined geochemical and diatom data,whose results were highlighted in 3 groups：Group 1,with low p H（1.9–5.1）and high metal/metalloid（Al,As,Cd,Co,Cu,Fe,Mn,Ni,Pb,Zn;0.65–1032 mg/L）and SO4（405–39124 mg/L）*** acidophilic species,Pinnularia aljustrelica,was perfectly adapted to the adverse conditions;in contrast,teratological forms of Eunotia exigua were found,showing that metal toxicity affected this *** low availability of metals/metalloids in sediments of this group indicates that metals/metalloids of the exchangeable fractions had been solubilized,which in fact enables metal/metalloid diatom uptake and consequently the occurrence of teratologies;Group 2,with sites of near neutral p H（5.0–6.8）and intermediate metal/metalloid（0.002–6 mg/L）and SO4（302–2179 mg/L）concentrations;this enabled the existence of typical species of uncontaminated streams（Brachysira neglectissima,Achnanthidium minutissimum）;Group 3,with samples from unimpacted sites,showing low metal/metalloid（0–0.8 mg/L）and SO4（10–315 mg/L）concentrations,high pH（7.0–8.4）and Cl contents（10–2119 mg/L）and the presence of brackish to marine species（Entomoneis paludosa）.For similar conditions of acidity,differences in diversity,abundance and teratologies of diatoms can be explained by the levels of metals/metalloids.

关键词： Surface waters Stream sediments Diatoms Metals/metalloids AMD Teratologies

High-throughput phenotyping of two plant-size traits of Eucalyptus species using neural networks

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Journal of Forestry Research 2022年第2期33卷 591-599页

作者： Marcus Vinicius Vieira borges Janielle de Oliveira Garcia Tays silva Batista Alexsandra Nogueira Martins silva Fabio Henrique Rojo Baio Carlos Antônio da silva Junior Gileno Brito de Azevedo Glauce Taís de Oliveira Sousa Azevedo Larissa Pereira Ribeiro Teodoro Paulo eduardo Teodoro Federal University of Mato Grosso Do Sul(UFMS) Chapadão Do SulMato Grosso Do Sul 79560000Brazil Department of Geography State University of Mato Grosso(UNEMAT)SinopMato Grosso 78555000Brazil

In forest modeling to estimate the volume of wood,artificial intelligence has been shown to be quite effi-cient,especially using artificial neural networks(ANNs).Here we tested whether diameter at breast height(DBH)and the total plant height(Ht)of eucalyptus can be pre-dicted at the stand level using spectral bands measured by an unmanned aerial vehicle(UAV)multispectral sensor and vegetation *** do so,using the data obtained by the UAV as input variables,we tested different configurations(number of hidden layers and number of neurons in each layer)of ANNs for predicting DBH and Ht at stand level for different Eucalyptus *** experimental design was randomized blocks with four replicates,with 20 trees in each experimental *** treatments comprised five Eucalyptus species(***,***,***,***-dis,and ***)and Corymbria *** and Ht for each plot at the stand level were measured seven times in separate overflights by the UAV,so that the multispectral sensor could obtain spectral bands to calculate vegetation indices(VIs).ANNs were then constructed using spectral bands and VIs as input layers,in addition to the categorical variable (species), to predict DBH and Ht at the stand level simultaneously. This report represents one of the first appli-cations of high-throughput phenotyping for plant size traits in Eucalyptus species. In general, ANNs containing three hidden layers gave better statistical performance (higher esti-mated r, lower estimated root mean squared error-RMSE) due to their greater capacity for self-learning. Among these ANNs, the best contained eight neurons in the first layer, seven in the second, and five in the third (8 − 7 − 5). The results reported here reveal the potential of using the gener-ated models to perform accurate forest inventories based on spectral bands and VIs obtained with a UAV multispectral sensor and ANNs, reducing labor and time.

关键词： Computational intelligence Diameter at breast height Forest inventory Remote sensing Vegetation indices