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| Registros recuperados : 10 | |
| 7. |  | DIAS, A.; ROWS, L. M.; SANTOS, S. G.; ALMEIDA, P. C.; CARVALHO, J.; SILVA, M. V.; XAVIER, G. R.; RUMJANEK, N. G.; RIBEIRO, R. L. D. Produção de auto-indutores de " Quorum Sensing" e efeitos sobre o crescimento de couve ( Brassica oleracea var.acephala) por Pseudomonas spp. isoladas do solo e da rizosfera de hortaliças. In: CONGRESSO BRASILEIRO DE CIÊNCIA DO SOLO, 32.; 2 a 7 da agosto de 2009, Fortaleza. O solo e a produção de bionergia: perspectivas e desafios: trabalhos científicos.... Fortaleza: Sociedade Brasileira de Ciência do Solo, 2009. 04 p| Biblioteca(s): Embrapa Agrobiologia. |
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| 8. | | CONGIO, G. F. de S.; CORSI, M.; ALMEIDA, P. C. de; GOULART, R. C. D.; PASSOS, L. P.; KOPP, M. M. Rebrota do capim-marandu submetido ao ataque de cigarrinhas. Arquivos do Instituto Biológico, São Paulo, v. 79, n. 3, p. 389-396, jul./set. 2012.| Biblioteca(s): Embrapa Pecuária Sul. |
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| 9. | | MIRANDA, C. R. de; BERNARDO, E. L.; MATTHIENSEN, A.; SEGANFREDO, G. C.; CORREA, J. C.; MONTICELLI, C. J.; ALMEIDA, P. C. de; PICCOLI, J. H.; SFOGIA. I.; GIACOMIN, N. J. Caracterização ambiental da microbacia do lajeado São Francisco em Presidente Castello Branco, SC. , 48 p. Concórdia: Embrapa Suínos e Aves, 2021. 48 p. (Embrapa Suínos e Aves. Documentos, 222).| Biblioteca(s): Embrapa Suínos e Aves. |
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| 10. | | DAMASCENO, B. C.; SILVA, M. da E.; LEAL, J. W. L.; AMARAL, J. A. F. do; JORGE, H. S. Z. E.; GONCALVES, H. S.; MELO, J. P. S. de; GUIMARAEAS, G.; DALEIRO, V.; BRAGA, J. B. P.; SILVA, A. R. B. da; ALMEIDA, P. C. de; CARVALHO, R. J. C. de; OLIVEIRA, V. J. de LOPES, W. de M. Programa de integração mineral no município de Conceição do Araguaia. Belém, PA: CPRM: SECOM; Conceição do Araguaia: Prefeitura Municipal de Conceição do Araguaia, 1996. 84 p. il.| Biblioteca(s): Embrapa Amazônia Oriental. |
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| Registros recuperados : 10 | |
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Registro Completo
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Biblioteca(s): |
Embrapa Florestas. |
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Data corrente: |
05/11/2014 |
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Data da última atualização: |
05/11/2014 |
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Tipo da produção científica: |
Artigo em Anais de Congresso |
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Autoria: |
MAIA, O. M. de A.; SCHNEIDER, F. K.; MAIA, J. M.; NEVES, L. C.; PENTEADO, S. do R. C. |
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Afiliação: |
Ozana Maria de Andrade Maia, UTFPR; Fabio Kurt Schneider, UTFPR; Joaquim Miguel Maia, UTFPR; Larissa Comar Neves, UTFPR; SUSETE DO ROCIO CHIARELLO PENTEADO, CNPF. |
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Título: |
Wood characterization using the power spectral density and phase velocity of ultrasonic signals. |
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Ano de publicação: |
2014 |
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Fonte/Imprenta: |
In: INTERNATIONAL ULTRASONICS SYMPOSIUM, 2014, Chicago. Proceedings. [S.l.]: IEEE, 2014. |
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Páginas: |
p. 1416-1419. |
|
Descrição Física: |
Disponibilizado online. |
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Idioma: |
Inglês |
|
Conteúdo: |
The application of non-destructive testing (NDT) in the analysis of trees in forest plantations permits the evaluation of the wood quality, the internal defects in development or pest attack and its characterization for application as solid wood and its products. These techniques have been constantly improved with the use of computers, electronics and agricultural control levels in order to provide tools to the specialists in integrated management. The ultrasound has been used in agriculture as NDT to determine the elasticity modulus of juvenile and mature wood of pinus and other species. This study aimed to the evaluation of new techniques for characterization of wood using parameters such as the power spectral density (PSD) and phase velocity of ultrasonic signals propagating in wood. The tests were performed using a pair of ultrasonic transducers with central frequency of 50 kHz (083-067-038, GE) which were connected to an ultrasonic pulser/receiver (5077PR, Olympus). The transmitting transducer was coupled to the samples of pinus using ultrasound gel and excited with negative pulses of short duration (5 μs) and high amplitude (-400 V) to generate longitudinal and shear waves. The ultrasound signals that propagated through the samples were received by the receiving transducer, amplified (20 to 40 dB), acquired in a digital scope (MSO4104B, Tektronix) and then transferred to a microcomputer. The tests have been done with 10 reference samples (healthy) and 10 attacked by wood wasps, with small holes in the bark. The transducers were placed on the samples in the axial, radial and inclined modes. The data were processed using the Matlab (Mathworks Inc.) to determine the power spectral density (PSD), the root mean square deviation index (cRMSDdB) and the phase velocity between the reference and attacked samples. The cRMSDdB calculated between the PSD of the reference and the attacked samples were generally higher for samples with higher degree of damage, however, in some cases, they were lower due to the presence of wood knots. The phase velocities were calculated in the frequency range 1-200 kHz and generally show higher values for the reference samples. The group velocities were also calculated and the results were in the range 1200-3000 m/s, indicating that these parameters can be used for wood characterization. MenosThe application of non-destructive testing (NDT) in the analysis of trees in forest plantations permits the evaluation of the wood quality, the internal defects in development or pest attack and its characterization for application as solid wood and its products. These techniques have been constantly improved with the use of computers, electronics and agricultural control levels in order to provide tools to the specialists in integrated management. The ultrasound has been used in agriculture as NDT to determine the elasticity modulus of juvenile and mature wood of pinus and other species. This study aimed to the evaluation of new techniques for characterization of wood using parameters such as the power spectral density (PSD) and phase velocity of ultrasonic signals propagating in wood. The tests were performed using a pair of ultrasonic transducers with central frequency of 50 kHz (083-067-038, GE) which were connected to an ultrasonic pulser/receiver (5077PR, Olympus). The transmitting transducer was coupled to the samples of pinus using ultrasound gel and excited with negative pulses of short duration (5 μs) and high amplitude (-400 V) to generate longitudinal and shear waves. The ultrasound signals that propagated through the samples were received by the receiving transducer, amplified (20 to 40 dB), acquired in a digital scope (MSO4104B, Tektronix) and then transferred to a microcomputer. The tests have been done with 10 reference samples (healthy) and 10 attacked ... Mostrar Tudo |
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Palavras-Chave: |
Material characterization; Método não destrutivo; Qualidade da madeira; Ultrasound. |
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Thesagro: |
Ultrassom. |
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Thesaurus NAL: |
Pinus; wood quality. |
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Categoria do assunto: |
-- |
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URL: |
https://www.alice.cnptia.embrapa.br/alice/bitstream/doc/999260/1/2014SuseteIUSWood.pdf
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Marc: |
LEADER 03178nam a2200253 a 4500
001 1999260
005 2014-11-05
008 2014 bl uuuu u00u1 u #d
100 1 $aMAIA, O. M. de A.
245 $aWood characterization using the power spectral density and phase velocity of ultrasonic signals.$h[electronic resource]
260 $aIn: INTERNATIONAL ULTRASONICS SYMPOSIUM, 2014, Chicago. Proceedings. [S.l.]: IEEE$c2014
300 $ap. 1416-1419.$cDisponibilizado online.
520 $aThe application of non-destructive testing (NDT) in the analysis of trees in forest plantations permits the evaluation of the wood quality, the internal defects in development or pest attack and its characterization for application as solid wood and its products. These techniques have been constantly improved with the use of computers, electronics and agricultural control levels in order to provide tools to the specialists in integrated management. The ultrasound has been used in agriculture as NDT to determine the elasticity modulus of juvenile and mature wood of pinus and other species. This study aimed to the evaluation of new techniques for characterization of wood using parameters such as the power spectral density (PSD) and phase velocity of ultrasonic signals propagating in wood. The tests were performed using a pair of ultrasonic transducers with central frequency of 50 kHz (083-067-038, GE) which were connected to an ultrasonic pulser/receiver (5077PR, Olympus). The transmitting transducer was coupled to the samples of pinus using ultrasound gel and excited with negative pulses of short duration (5 μs) and high amplitude (-400 V) to generate longitudinal and shear waves. The ultrasound signals that propagated through the samples were received by the receiving transducer, amplified (20 to 40 dB), acquired in a digital scope (MSO4104B, Tektronix) and then transferred to a microcomputer. The tests have been done with 10 reference samples (healthy) and 10 attacked by wood wasps, with small holes in the bark. The transducers were placed on the samples in the axial, radial and inclined modes. The data were processed using the Matlab (Mathworks Inc.) to determine the power spectral density (PSD), the root mean square deviation index (cRMSDdB) and the phase velocity between the reference and attacked samples. The cRMSDdB calculated between the PSD of the reference and the attacked samples were generally higher for samples with higher degree of damage, however, in some cases, they were lower due to the presence of wood knots. The phase velocities were calculated in the frequency range 1-200 kHz and generally show higher values for the reference samples. The group velocities were also calculated and the results were in the range 1200-3000 m/s, indicating that these parameters can be used for wood characterization.
650 $aPinus
650 $awood quality
650 $aUltrassom
653 $aMaterial characterization
653 $aMétodo não destrutivo
653 $aQualidade da madeira
653 $aUltrasound
700 1 $aSCHNEIDER, F. K.
700 1 $aMAIA, J. M.
700 1 $aNEVES, L. C.
700 1 $aPENTEADO, S. do R. C.
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Embrapa Florestas (CNPF) |
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