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Registro Completo |
Biblioteca(s): |
Embrapa Instrumentação. |
Data corrente: |
22/12/1999 |
Data da última atualização: |
22/12/1999 |
Autoria: |
POSADAS, D. A.; TANNUS, A.; PANEPUCCI, H.; CRESTANA, S. |
Afiliação: |
Universidade Estadual de Ponta Grossa; EMBRAPA-CNPDIA; USP-IFSC. |
Título: |
Magnetic resonance imaging as a non-invasive technique for investigating 3-D preferential flow occurring within stratified soil samples. |
Ano de publicação: |
1996 |
Fonte/Imprenta: |
Computers and Electronics in Agriculture, Amsterdam, v.14, n.4, p.255-267, Apr. 1996. |
Idioma: |
Inglês |
Conteúdo: |
The soil fingering phenomenon was investigated using magnetic resonance imaging (MRI) as an appropriate technique. A cubic 15x15x15-cm3 double-layer sand column was built in order to simulate the stratified soil. The column was imaged in a 500 Gaus NMR tomograph [IFQSC, USP, Sao Carlos (SP)]. After reaching the water steady-state flow several coronal, transverse, and sagittal images of the column were obtained. For each case seven slices, 1.8cm thick and separated by 2.0cm center to center, were collected providing three-dimensional information regardingto the number of fingers, their sizes and diameters. To study the fingering dynamics employing MRI concepts, another kind of experiment was performed by following only the water front (no image reconstruction), using spin-echo signals with phase encoding along vertical axis (gravitational direction), but with phase encoding gradients switched off. Sixteen acquisitions of seven transverses of 2cm thick slices, were performed in a 3-min experiment. After suitable treatment, the water front and the horizontal distribution at each measured time during the water infiltration process was obtained. Normalizing the signal intensities to the soil column dimensions and using computational graphic resources, made it possible to quantify the number of fingers and their spatial and temporal variability. The results elect MRI as a valuable tool for non-invasively investigating the dynamics of soil fingering phenomenon. |
Palavras-Chave: |
Fingering; Fractal; Gravity force; Imaging; NMR tomography; Nuclear magnetic resonance; Spin echo signal. |
Categoria do assunto: |
-- |
Marc: |
LEADER 02221naa a2200241 a 4500 001 1026423 005 1999-12-22 008 1996 bl --- 0-- u #d 100 1 $aPOSADAS, D. A. 245 $aMagnetic resonance imaging as a non-invasive technique for investigating 3-D preferential flow occurring within stratified soil samples. 260 $c1996 520 $aThe soil fingering phenomenon was investigated using magnetic resonance imaging (MRI) as an appropriate technique. A cubic 15x15x15-cm3 double-layer sand column was built in order to simulate the stratified soil. The column was imaged in a 500 Gaus NMR tomograph [IFQSC, USP, Sao Carlos (SP)]. After reaching the water steady-state flow several coronal, transverse, and sagittal images of the column were obtained. For each case seven slices, 1.8cm thick and separated by 2.0cm center to center, were collected providing three-dimensional information regardingto the number of fingers, their sizes and diameters. To study the fingering dynamics employing MRI concepts, another kind of experiment was performed by following only the water front (no image reconstruction), using spin-echo signals with phase encoding along vertical axis (gravitational direction), but with phase encoding gradients switched off. Sixteen acquisitions of seven transverses of 2cm thick slices, were performed in a 3-min experiment. After suitable treatment, the water front and the horizontal distribution at each measured time during the water infiltration process was obtained. Normalizing the signal intensities to the soil column dimensions and using computational graphic resources, made it possible to quantify the number of fingers and their spatial and temporal variability. The results elect MRI as a valuable tool for non-invasively investigating the dynamics of soil fingering phenomenon. 653 $aFingering 653 $aFractal 653 $aGravity force 653 $aImaging 653 $aNMR tomography 653 $aNuclear magnetic resonance 653 $aSpin echo signal 700 1 $aTANNUS, A. 700 1 $aPANEPUCCI, H. 700 1 $aCRESTANA, S. 773 $tComputers and Electronics in Agriculture, Amsterdam$gv.14, n.4, p.255-267, Apr. 1996.
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Embrapa Instrumentação (CNPDIA) |
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Registro Completo
Biblioteca(s): |
Embrapa Amazônia Oriental. |
Data corrente: |
18/11/1998 |
Data da última atualização: |
17/08/2012 |
Autoria: |
CARDOSO, E. M. R. |
Afiliação: |
ELOISA MARIA RAMOS CARDOSO, CPATU. |
Título: |
Situação atual da mandioca na Amazônia. |
Ano de publicação: |
1984 |
Fonte/Imprenta: |
In: SIMPÓSIO DO TRÓPICO ÚMIDO, 1., 1984, Belém, PA. Resumos. Belém, PA: EMBRAPA-CPATU, 1984. |
Páginas: |
p. 170-171. |
Série: |
(EMBRAPA-CPATU. Documentos, 31). |
Idioma: |
Português |
Palavras-Chave: |
Brasil; Natural distribution; Plant diseases. |
Thesagro: |
Distribuição Geográfica; Doença; Mandioca; Pesquisa; Praga; Produtividade. |
Thesaurus NAL: |
Amazonia; cassava; pests; research; yields. |
Categoria do assunto: |
-- |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/64045/1/Doc31-p170.pdf
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Marc: |
LEADER 00806naa a2200301 a 4500 001 1394848 005 2012-08-17 008 1984 bl uuuu u00u1 u #d 100 1 $aCARDOSO, E. M. R. 245 $aSituação atual da mandioca na Amazônia. 260 $c1984 300 $ap. 170-171. 490 $a(EMBRAPA-CPATU. Documentos, 31). 650 $aAmazonia 650 $acassava 650 $apests 650 $aresearch 650 $ayields 650 $aDistribuição Geográfica 650 $aDoença 650 $aMandioca 650 $aPesquisa 650 $aPraga 650 $aProdutividade 653 $aBrasil 653 $aNatural distribution 653 $aPlant diseases 773 $tIn: SIMPÓSIO DO TRÓPICO ÚMIDO, 1., 1984, Belém, PA. Resumos. Belém, PA: EMBRAPA-CPATU, 1984.
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