87 research outputs found

    Análise da qualidade superficial e da microdureza de aço inoxidável martensítico após a retificação / Analysis of surface quality and microhardness of martensitic stainless steel after grinding

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    Aços inoxidáveis são materiais com elevada resistência à corrosão que são empregados em vários setores, como metal mecânica, automobilístico, petroquímico e aeroespacial, como também no setor de cutelaria. E para este último setor, os mais empregados são os aços inoxidáveis martensíticos. Entretanto, estes possuem uma pobre usinabilidade e, mais especificamente, pobre retificabilidade com rebolos abrasivos convencionais em relação aos aços endurecidos. Nesse sentido, este trabalho visa analisar o acabamento da superfície (em termos de rugosidade) e a microdureza do aço inoxidável martensítico VP420 após a retificação com rebolo abrasivo convencional de óxido de alumínio branco. Como parâmetros de corte foi variada a penetração de trabalho (10 µm e 25 µm). As velocidades de corte e da peça foram mantidas constantes em 37 m/s e 10 m/min, respectivamente. Como resultados, observou-se que o acabamento piorou com o aumento de ambos Ra e Rz, como também se constatou maior variação na faixa de microdureza abaixo da superfície retificada ao empregar a maior penetração de trabalho.

    Content of basil essential oil on a loam texture soil under water regimes and different harvest stages

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    The essential oil of basil (Ocimum basilicum L.) has high economic value and is produced in the plant by secondary metabolism. Its quantity and composition tend to vary as a response of the plant to stress situations due to changes in the environment and phenological phase. This work aimed to evaluate the development, the chemical composition, content, and the yield of essential oil of basil rich in Linalool, as a function of the soil water tensions and the harvest stages, in a loam texture soil. The experiment was carried out in a greenhouse and consisted of three harvest times (BF - beginning of flowering,  FF - full flowering,  and EF - end of flowering) and five values of soil water tension to define when to irrigate (20, 30, 40, 50, and 60 kPa), totalizing 15 treatments. The irrigation in the soil water tension of 60 kPa generated a reduction in the content and the yield of essential oils compared with 20 kPa, only in the FF harvest stage. However, it did not modify the composition of the essential oil. Regardless of the soil water tension to define irrigation, the highest levels and yields of essential oil were found in the EF harvest stage. Harvest stages did not change the composition of the essential oil or the content of Linalool. In turn, the contents of the components Cineol, Camphor, ∝-Terpeneol, and Isobornyl acetate increased with the harvesting period from BF to EF. Eugenol had the opposite trend, reducing the content from BF to EF. Linalool, a component in greater proportion in essential oil, showed a higher content in soil water tensions up to 50 kPa, decreasing only by 60 kPa. In loam textured soils, it is recommended that basil producers, who aim to extract Linalool, irrigate when the soil water tension reaches up to 50 kPa, with the harvest at any stage of flowering

    Show da Física: uma aprendizagem significativa

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    O presente trabalho visa relatar a experiência do projeto Show da Física, realizado por um professor atuante em uma escola rural da rede estadual paulista. Para o aporte teórico os autores elucidados são Gauthier, Bissonnette e Richard (2014), Bissonnette e Richard (2013), Roldão (2009), Izquierdo (2011) entre outros. Como procedimento metodológico adotamos a descrição do contexto escolar, descrição do projeto Show da Física, da distribuição dos experimentos, da montagem e organização da sala de aula, da apresentação no dia da feira e as consequências do pós-projeto. Ela se encerrou com uma avaliação que busca um feedback do aluno e da sua experiência frente a todo o processo. Conclui-se que a estratégia de ensino descrita promoveu elementos que são relevantes ao desenvolvimento global do aluno, como: Oralidade, trabalho em equipe, organização, pesquisa, apresentação das ideias e respeito aos prazos de cada etapa. Observa-se, ainda, que o papel do professor foi fundamental para um ensino eficaz.

    Alimentação popular em São Paulo (1920 a 1950): políticas públicas, discursos técnicos e práticas profissionais

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    This article discusses how the concept of lower-class eating habits came about and developed in the intellectual circles of São Paulo during the first half of the 20th century. It starts by reconstructing the elements of the debate around the income and ignorance of the underprivileged as the main reasons behind their bad eating habits. Then, it looks at the focal points for interventions and public policies proposed by the government to deal with the problem thus identified, namely: training methods to produce sanitation counselors capable of offering dietary guidance as well; popular educational campaigns and new learning sites in addition to schools (e.g. healthcare centers and households); lunch and other means of offering food at schools; and diagnostic studies about food intake and eating habits among laborers. Because they were translated into technical and scientific language, the proposals and policies implemented in São Paulo left traces in a variety of supporting documents and media (photographs, primers, posters, inquiry notebooks, and academic literature).O artigo discute a construção da idéia de alimentação popular nos meios intelectuais em São Paulo, na primeira metade do século XX. Para isso, reconstitui, como motivos da má alimentação, elementos do debate em torno da renda e da ignorância dos mais pobres. Identificado o problema, as propostas de intervenção e as políticas públicas concentraram-se em alguns setores, abordados neste trabalho: métodos para a formação de educadores sanitários aptos a atuar também na educação alimentar; campanhas de instrução popular e criação de novos lugares de aprendizado (além das escolas, os centros de saúde e os lares); merenda escolar e outras alternativas de alimentação nas escolas; e diagnósticos referentes ao conteúdo e à forma da alimentação dos operários. Traduzidas em discurso técnico-científicos, as propostas e políticas implementadas na cidade deixaram indícios em documentação de suporte e tipologia variados (fotografias, cartilhas, cartazes, cadernetas de inquéritos e textos acadêmicos).Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Considerações gerais sobre a síncope: uma abordagem clínica : General considerations about syncope: a clinical approach

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    O seguinte estudo objetivou descrever sobre as etiologias e o respectivo quadro clínico da síncope. A síncope é classificado como um sintoma de perda da consciência devido redução do fluxo sanguíneo cerebral, secundário a uma etiologia. Tal evento costuma ser confundido com outras condições associadas a perda de conhecimento, apesar de para se diagnosticar como síncope é necessário descartar demais alterações. A síncope é uma condição que têm como fisiopatologia o hipofluxo de sangue no cérebro, mas conta com diversas causas como a neuromediada, ortostática, cardíaca, cerebrovascular e até idiopática,  resultam em quadros clínicos distintos e complicações, mas o mesmo desfecho. Tal evento necessita ser investigado e detectado de imediato, por história clínica, exame físico e complementares

    Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

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    Funding: Data collection was largely funded by the UK Natural Environment Research Council (NERC) project TREMOR (NE/N004655/1) to D.G., E.G. and O.P., with further funds from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001) to J.V.T. and a University of Leeds Climate Research Bursary Fund to J.V.T. D.G., E.G. and O.P. acknowledge further support from a NERC-funded consortium award (ARBOLES, NE/S011811/1). This paper is an outcome of J.V.T.’s doctoral thesis, which was sponsored by CAPES (GDE 99999.001293/2015-00). J.V.T. was previously supported by the NERC-funded ARBOLES project (NE/S011811/1) and is supported at present by the Swedish Research Council Vetenskapsrådet (grant no. 2019-03758 to R.M.). E.G., O.P. and D.G. acknowledge support from NERC-funded BIORED grant (NE/N012542/1). O.P. acknowledges support from an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. R.S.O. was supported by a CNPq productivity scholarship, the São Paulo Research Foundation (FAPESP-Microsoft 11/52072-0) and the US Department of Energy, project GoAmazon (FAPESP 2013/50531-2). M.M. acknowledges support from MINECO FUN2FUN (CGL2013-46808-R) and DRESS (CGL2017-89149-C2-1-R). C.S.-M., F.B.V. and P.R.L.B. were financed by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001). C.S.-M. received a scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq 140353/2017-8) and CAPES (science without borders 88881.135316/2016-01). Y.M. acknowledges the Gordon and Betty Moore Foundation and ERC Advanced Investigator Grant (GEM-TRAITS, 321131) for supporting the Global Ecosystems Monitoring (GEM) network (gem.tropicalforests.ox.ac.uk), within which some of the field sites (KEN, TAM and ALP) are nested. The authors thank Brazil–USA Collaborative Research GoAmazon DOE-FAPESP-FAPEAM (FAPESP 2013/50533-5 to L.A.) and National Science Foundation (award DEB-1753973 to L. Alves). They thank Serrapilheira Serra-1709-18983 (to M.H.) and CNPq-PELD/POPA-441443/2016-8 (to L.G.) (P.I. Albertina Lima). They thank all the colleagues and grants mentioned elsewhere [8,36] that established, identified and measured the Amazon forest plots in the RAINFOR network analysed here. The authors particularly thank J. Lyod, S. Almeida, F. Brown, B. Vicenti, N. Silva and L. Alves. This work is an outcome approved Research Project no. 19 from ForestPlots.net, a collaborative initiative developed at the University of Leeds that unites researchers and the monitoring of their permanent plots from the world’s tropical forests [61]. The authros thank A. Levesley, K. Melgaço Ladvocat and G. Pickavance for ForestPlots.net management. They thank Y. Wang and J. Baker, respectively, for their help with the map and with the climatic data. The authors acknowledge the invaluable help of M. Brum for kindly providing the comparison of vulnerability curves based on PAD and on PLC shown in this manuscript. They thank J. Martinez-Vilalta for his comments on an early version of this manuscript. The authors also thank V. Hilares and the Asociación para la Investigación y Desarrollo Integral (AIDER, Puerto Maldonado, Peru); V. Saldaña and Instituto de Investigaciones de la Amazonía Peruana (IIAP) for local field campaign support in Peru; E. Chavez and Noel Kempff Natural History Museum for local field campaign support in Bolivia; ICMBio, INPA/NAPPA/LBA COOMFLONA (Cooperativa mista da Flona Tapajós) and T. I. Bragança-Marituba for the research support.Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, Ψ50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters Ψ50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both Ψ50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.Publisher PDFPeer reviewe

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data

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    This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys
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