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 | Acesso ao texto completo restrito à biblioteca da Embrapa Instrumentação. Para informações adicionais entre em contato com cnpdia.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
26/08/2020 |
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Data da última atualização: |
16/08/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
FARIA, D. L.; MESQUITA JUNIOR, L.; RESENDE, A. A.; LOPES, D. E.; MENDES, L. M.; MARTINS, M. A.; MARCONCINI, J. M.; GUIMARÃES JUNIOR, J. B. |
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Afiliação: |
MARIA ALICE MARTINS, CNPDIA; JOSE MANOEL MARCONCINI, CNPDIA. |
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Título: |
Physical and mechanical properties of polyurethane thermoset matrices reinforced with green coconut fibres. |
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Ano de publicação: |
2020 |
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Fonte/Imprenta: |
Journal of Composite Materials, v. 54, n. 30, 2020. |
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Páginas: |
4841-4852 |
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DOI: |
10.1177/0021998320940023 |
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Idioma: |
Inglês |
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Conteúdo: |
Currently, the use of composites to replace parts made only with plastics has been gradually employed. The advantages of these composites are low cost, high availability of raw materials and good physical and mechanical properties. Thus, this work aimed at producing and characterizing composites produced with coconut fibre reinforced polyurethane matrices. The coconut fibres were studied as to their chemical constituents, aspect ratio, bulk density, pH, tensile properties, and surface SEM images. The composites were prepared using the hand lay-up process and four different concentrations of coconut fibre were evaluated: 30, 40, 50, and 60%. The composites were assessed as for water absorption after 20 days of immersion, bulk density, impact IZOD, tensile tests, and visualize the matrix-reinforcement interface using SEM. The electron micrographs showed a great deal of impurities on the surface of coconut fibres, such as greases, waxes, and gums, due to the high amount of extraction material (19.78%), which damages the adherence of the polymer onto the coconut fibre and, as observed, cause detachment between the reinforcement and the matrix. The tensile strength of the composites tended to increase as greater amounts of coconut fibres were added to the matrix. The averages were around 6.51 to 6.72 MPa for composites with 30 and 60% fibres, respectively. Therefore, coconut fibres can be considered as an alternative to synthetic fibres commonly used in composites, and they can be used at a ratio of 60% without prejudicing the properties of the composites, making them lighter and cheaper. MenosCurrently, the use of composites to replace parts made only with plastics has been gradually employed. The advantages of these composites are low cost, high availability of raw materials and good physical and mechanical properties. Thus, this work aimed at producing and characterizing composites produced with coconut fibre reinforced polyurethane matrices. The coconut fibres were studied as to their chemical constituents, aspect ratio, bulk density, pH, tensile properties, and surface SEM images. The composites were prepared using the hand lay-up process and four different concentrations of coconut fibre were evaluated: 30, 40, 50, and 60%. The composites were assessed as for water absorption after 20 days of immersion, bulk density, impact IZOD, tensile tests, and visualize the matrix-reinforcement interface using SEM. The electron micrographs showed a great deal of impurities on the surface of coconut fibres, such as greases, waxes, and gums, due to the high amount of extraction material (19.78%), which damages the adherence of the polymer onto the coconut fibre and, as observed, cause detachment between the reinforcement and the matrix. The tensile strength of the composites tended to increase as greater amounts of coconut fibres were added to the matrix. The averages were around 6.51 to 6.72 MPa for composites with 30 and 60% fibres, respectively. Therefore, coconut fibres can be considered as an alternative to synthetic fibres commonly used in composites, and they can b... Mostrar Tudo |
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Palavras-Chave: |
Thermoset matrices. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02357naa a2200241 a 4500
001 2124574
005 2022-08-16
008 2020 bl uuuu u00u1 u #d
024 7 $a10.1177/0021998320940023$2DOI
100 1 $aFARIA, D. L.
245 $aPhysical and mechanical properties of polyurethane thermoset matrices reinforced with green coconut fibres.$h[electronic resource]
260 $c2020
300 $a4841-4852
520 $aCurrently, the use of composites to replace parts made only with plastics has been gradually employed. The advantages of these composites are low cost, high availability of raw materials and good physical and mechanical properties. Thus, this work aimed at producing and characterizing composites produced with coconut fibre reinforced polyurethane matrices. The coconut fibres were studied as to their chemical constituents, aspect ratio, bulk density, pH, tensile properties, and surface SEM images. The composites were prepared using the hand lay-up process and four different concentrations of coconut fibre were evaluated: 30, 40, 50, and 60%. The composites were assessed as for water absorption after 20 days of immersion, bulk density, impact IZOD, tensile tests, and visualize the matrix-reinforcement interface using SEM. The electron micrographs showed a great deal of impurities on the surface of coconut fibres, such as greases, waxes, and gums, due to the high amount of extraction material (19.78%), which damages the adherence of the polymer onto the coconut fibre and, as observed, cause detachment between the reinforcement and the matrix. The tensile strength of the composites tended to increase as greater amounts of coconut fibres were added to the matrix. The averages were around 6.51 to 6.72 MPa for composites with 30 and 60% fibres, respectively. Therefore, coconut fibres can be considered as an alternative to synthetic fibres commonly used in composites, and they can be used at a ratio of 60% without prejudicing the properties of the composites, making them lighter and cheaper.
653 $aThermoset matrices
700 1 $aMESQUITA JUNIOR, L.
700 1 $aRESENDE, A. A.
700 1 $aLOPES, D. E.
700 1 $aMENDES, L. M.
700 1 $aMARTINS, M. A.
700 1 $aMARCONCINI, J. M.
700 1 $aGUIMARÃES JUNIOR, J. B.
773 $tJournal of Composite Materials$gv. 54, n. 30, 2020.
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Registro original: |
Embrapa Instrumentação (CNPDIA) |
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Biblioteca |
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Biblioteca(s): |
Embrapa Meio Ambiente; Embrapa Pecuária Sudeste. |
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Data corrente: |
06/03/2023 |
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Data da última atualização: |
23/03/2023 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
ALMEIDA, S. L. H. DE; SOUSA, J. B. C.; NOGUEIRA, S. F.; PEZZOPANE, J. R. M.; TEIXEIRA, A. H. DE C.; BOSI, C.; ADAMI, M.; ZERBATO, C.; BERNARDI, A. C. de C.; SILVA, G. B. S. da; SILVA, R. P. DA. |
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Afiliação: |
SAMIRA LUNS HATUM DE ALMEIDA, São Paulo State University; JARLYSON BRUNNO COSTA SOUZA, São Paulo State University; SANDRA FURLAN NOGUEIRA, CNPMA; JOSE RICARDO MACEDO PEZZOPANE, CPPSE; ANTÔNIO HERIBERTO DE CASTRO TEIXEIRA, Federal University of Sergipe; CRISTIAM BOSI; MARCOS ADAMI, National Institute for Space Research; CRISTIANO ZERBATO, São Paulo State University; ALBERTO CARLOS DE CAMPOS BERNARDI, CPPSE; GUSTAVO BAYMA SIQUEIRA DA SILVA, CNPMA; ROUVERSON PEREIRA DA SILVA, São Paulo State University. |
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Título: |
Forage mass estimation in silvopastoral and full sun systems: evaluation through proximal remote sensing applied to the SAFER model. |
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Ano de publicação: |
2023 |
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Fonte/Imprenta: |
Remote Sensing, v. 15, n. 3, jan. 2023. |
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Páginas: |
18 p. |
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DOI: |
ttps://doi.org/10.3390/rs15030815 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: The operational slowness in the execution of direct methods for estimating forage mass, an important variable for defining the animal stocking rate, gave rise to the need for methods with faster responses and greater territorial coverage. In this context, the aim of this study was to evaluate a method to estimate the mass of Urochloa brizantha cv. BRS Piatã in shaded and full sun systems, through proximal sensing applied to the Simple Algorithm for Evapotranspiration Retrieving (SAFER) model, applied with the Monteith Radiation Use Efficiency (RUE) model. The study was carried out in the experimental area of Fazenda Canchim, a research center of Embrapa Pecuária Sudeste, São Carlos, SP, Brazil (21°57′S, 47°50′W, 860 m), with collections of forage mass and reflectance in the silvopastoral systems animal production and full sun. Reflectance data, as well as meteorological data obtained by a weather station installed in the study area, were used as input for the SAFER model and, later, for the radiation use efficiency model to calculate the fresh mass of forage. The forage collected in the field was sent to the laboratory, separated, weighed and dried, generating the variables of pasture total dry mass), total leaf dry mass, leaf and stalk dry mass and leaf area index. With the variables of pasture, in situ, and fresh mass, obtained from SAFER, the training regression model, in which 80% were used for training and 20% for testing the models. The SAFER was able to promisingly express the behavior of forage variables, with a significant correlation with all of them. The variables that obtained the best estimation performance model were the dry mass of leaves and stems and the dry mass of leaves in silvopastoral and full sun systems, respectively. It was concluded that the association of the SAFER model with the proximal sensor allowed us to obtain a fast, precise and accurate forage estimation method. MenosAbstract: The operational slowness in the execution of direct methods for estimating forage mass, an important variable for defining the animal stocking rate, gave rise to the need for methods with faster responses and greater territorial coverage. In this context, the aim of this study was to evaluate a method to estimate the mass of Urochloa brizantha cv. BRS Piatã in shaded and full sun systems, through proximal sensing applied to the Simple Algorithm for Evapotranspiration Retrieving (SAFER) model, applied with the Monteith Radiation Use Efficiency (RUE) model. The study was carried out in the experimental area of Fazenda Canchim, a research center of Embrapa Pecuária Sudeste, São Carlos, SP, Brazil (21°57′S, 47°50′W, 860 m), with collections of forage mass and reflectance in the silvopastoral systems animal production and full sun. Reflectance data, as well as meteorological data obtained by a weather station installed in the study area, were used as input for the SAFER model and, later, for the radiation use efficiency model to calculate the fresh mass of forage. The forage collected in the field was sent to the laboratory, separated, weighed and dried, generating the variables of pasture total dry mass), total leaf dry mass, leaf and stalk dry mass and leaf area index. With the variables of pasture, in situ, and fresh mass, obtained from SAFER, the training regression model, in which 80% were used for training and 20% for testing the models. The SAFER was ... Mostrar Tudo |
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Palavras-Chave: |
Digital agriculture; ILPF; Proximal sensor. |
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Thesagro: |
Biomassa; Capim Urochloa; Gramínea Forrageira; Sistema de Informação Geográfica; Sombreamento. |
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Thesaurus NAL: |
Meteorological data; Urochloa brizantha. |
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Categoria do assunto: |
X Pesquisa, Tecnologia e Engenharia |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/doc/1152139/1/Nogueira-Forage-mass-2023.pdf
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Marc: |
LEADER 03114naa a2200385 a 4500
001 2152139
005 2023-03-23
008 2023 bl uuuu u00u1 u #d
024 7 $attps://doi.org/10.3390/rs15030815$2DOI
100 1 $aALMEIDA, S. L. H. DE
245 $aForage mass estimation in silvopastoral and full sun systems$bevaluation through proximal remote sensing applied to the SAFER model.$h[electronic resource]
260 $c2023
300 $a18 p.
520 $aAbstract: The operational slowness in the execution of direct methods for estimating forage mass, an important variable for defining the animal stocking rate, gave rise to the need for methods with faster responses and greater territorial coverage. In this context, the aim of this study was to evaluate a method to estimate the mass of Urochloa brizantha cv. BRS Piatã in shaded and full sun systems, through proximal sensing applied to the Simple Algorithm for Evapotranspiration Retrieving (SAFER) model, applied with the Monteith Radiation Use Efficiency (RUE) model. The study was carried out in the experimental area of Fazenda Canchim, a research center of Embrapa Pecuária Sudeste, São Carlos, SP, Brazil (21°57′S, 47°50′W, 860 m), with collections of forage mass and reflectance in the silvopastoral systems animal production and full sun. Reflectance data, as well as meteorological data obtained by a weather station installed in the study area, were used as input for the SAFER model and, later, for the radiation use efficiency model to calculate the fresh mass of forage. The forage collected in the field was sent to the laboratory, separated, weighed and dried, generating the variables of pasture total dry mass), total leaf dry mass, leaf and stalk dry mass and leaf area index. With the variables of pasture, in situ, and fresh mass, obtained from SAFER, the training regression model, in which 80% were used for training and 20% for testing the models. The SAFER was able to promisingly express the behavior of forage variables, with a significant correlation with all of them. The variables that obtained the best estimation performance model were the dry mass of leaves and stems and the dry mass of leaves in silvopastoral and full sun systems, respectively. It was concluded that the association of the SAFER model with the proximal sensor allowed us to obtain a fast, precise and accurate forage estimation method.
650 $aMeteorological data
650 $aUrochloa brizantha
650 $aBiomassa
650 $aCapim Urochloa
650 $aGramínea Forrageira
650 $aSistema de Informação Geográfica
650 $aSombreamento
653 $aDigital agriculture
653 $aILPF
653 $aProximal sensor
700 1 $aSOUSA, J. B. C.
700 1 $aNOGUEIRA, S. F.
700 1 $aPEZZOPANE, J. R. M.
700 1 $aTEIXEIRA, A. H. DE C.
700 1 $aBOSI, C.
700 1 $aADAMI, M.
700 1 $aZERBATO, C.
700 1 $aBERNARDI, A. C. de C.
700 1 $aSILVA, G. B. S. da
700 1 $aSILVA, R. P. DA
773 $tRemote Sensing$gv. 15, n. 3, jan. 2023.
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