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| Registros recuperados : 167 | |
| 83. |  | LUENGO, R. de F. A.; CALBO, A. G.; JACOBINO, Â. P.; PESSOA, J. D. C. Cenoura e tomate: altura máxima de empilhamento e qualidade. Horticultura Brasileira, Brasília, DF, v. 23, n. 2, ago. 2005. Suplemento 2. CD-ROM. Trabalho apresentado no 45. Congresso Brasileiro de Olericultura, Fortaleza, 2005. Publicado também como resumo em: Horticultura Brasileira, Brasília, DF, v. 23, n. 2, p. 438, ago. 2005. Suplemento 1.| Biblioteca(s): Embrapa Hortaliças. |
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| 84. | | LUENGO, R. de F. A.; CALBO, A. G.; JACOMINO, A. P.; PESSOA, J. D. C. Cenoura e tomate: altura máxima de empilhamento e qualidade. In: CONGRESSO BRASILEIRO DE OLERICULTURA, 45.; CONGRESSO BRASILEIRO DE FLORICULTURA E PLANTAS ORNAMENTAIS, 15.; CONGRESSO BRASILEIRO DE CULTURA DE TECIDOS DE PLANTAS, 2., 2005, Fortaleza. [Resumos...]. Fortaleza: Associação Brasileira de Horticultura, 2005. Suplemento da Revista da Associação Brasileira de Horticultura, v. 23, n. 2, ago. 2005.| Biblioteca(s): Embrapa Instrumentação. |
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| 86. | | MENDES, J. E.; CAMARGO, E. R.; SOUSA, C. P.; PESSOA, J. D. C. Ensaio in vitro do controle microbiano de enterococcus faecalis por nanopartículas de prata. In: WORKSHOP DA REDE DE NANOTECNOLOGIA APLICADA AO AGRONEGÓCIO, 7.; ESCOLA DE NANOTECNOLOGIA, 3., 2013, São Carlos, SP. Anais... São Carlos, SP: Embrapa Instrumentação, 2013. p. 571-572 Editores: Maria Alice Martins, Odílio Benedito Garrido de Assis, Caue Ribeiro, Luiz Henrique Capparelli Mattoso. CD-ROM. Editores: Maria Alice Martins, Odílio Benedito Garrido de Assis, Caue Ribeiro, Luiz Henrique Capparelli Mattoso.| Biblioteca(s): Embrapa Instrumentação. |
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| 89. | | BERTUCCI-NETO, V.; PESSOA, J. D. C.; CRUVINEL, P. E.; CALBO, A. G. Control systems-based design of a plant intracellular pressure measurement instrument. In: WORLD MULTICONFERENCE ON: CIRCUITS, SYSTEMS, COMMUNICATIONS AND COMPUTERS (IEEE/WSES/IMACS)-CSCC, 3., 1999, Athens, Grécia. CSCC'99: proceedings... [Athens]: World Scientific and Engineering Society, 1999. p.6231-6236, ref.623. Editor Nikos E. Mastorakis. Dedicated to the father of fuzzy logic: L. Zadeh. 1 CD-ROM.| Biblioteca(s): Embrapa Instrumentação. |
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| 90. | | CRESTANA, S.; PESSOA, J. D. C.; TORRE-NETO, A.; VAZ, C. M. P.; CALHEIROS, R. Densidade e umidade de um solo expansivo tipo glei medidas por tomografia de duplo feixe de raios gama. In: CONGRESSO BRASILEIRO DE CIENCIA DO SOLO, 23., jul. 1991, Porto Alegre, RS. Programa e resumos... Porto Alegre: Sociedade Brasileira de Ciencia do Solo, 1991. p.64. Ref.021.| Biblioteca(s): Embrapa Instrumentação. |
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| Registros recuperados : 167 | |
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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. |
Registro Completo
|
Biblioteca(s): |
Embrapa Instrumentação. |
|
Data corrente: |
01/02/2001 |
|
Data da última atualização: |
24/08/2010 |
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Autoria: |
BERTUCCI-NETO, V.; PESSOA, J. D. C.; CRUVINEL, P. E.; CALBO, A. G. |
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Afiliação: |
Embrapa Instrumentacao Agropecuaria. |
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Título: |
Control systems-based design of a plant intracellular pressure measurement instrument. |
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Ano de publicação: |
1999 |
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Fonte/Imprenta: |
In: MASTORAKIS, N. E. (Ed.). Computers and computational engineering in control. [Athens]: World Scientific and Engineering Society, 1999. |
|
Páginas: |
p. 199-203. |
|
ISBN: |
960-8052-12-2 |
|
Idioma: |
Inglês |
|
Conteúdo: |
Cell turgor (plant intracellular pressure) is a parameter very know by physiologists and its determination is fundamental for the evaluation of water relations of higher (multicellular) plants. It is largely used in studies of plant tolerance or resistance to various stresses caused by irregular supply of nutrients, water and some other factors required by plant organism. The determination of cell turgor is also important for the development of models for water transport in plant tissues. Although this matter is of great importance to the physiologists, there are a few papers discribing realistic techniques for this purpose. Basically, the most reliable developed devices consisted of capillary filled with oil. It was used to puncture a plant cell and the meniscus moved itself according to the intracellular pressure. A hydraulic apparatus driven by a DC motor was used for counteracting the cell fissure, impelling pressure in the sense of the plant cell. The effort dispensed by the motor was correlated with the cell pressure. In a previous paper we have applied by the first time a control system approach to this problem. It was possible to determine the feasible work ranges, stability conditions, performance. The hydraulic system plus the DC motor was changed by external controlled temperature acting over the capillary wall. However the meniscus position detection was exposed to ambient temperature causing noisy measurement. In order to overcome this problem we propose in this paper a new design based on Linear Quadratic methods, specifically Proportional plus Integral Estimators in conjunction with Proportional Plus Integral State Feedback Regulator Designs. Main idea is to profit by the robustness characteristics of a PI controller together with the setting of the filter bandwidths for good noise filtering and transient responses. Morover, PI estimator can be optimum for a plant process noise which is high in intensity at low frequencies. The system was modeled and simulations were performed using parameters in limit conditions either of stability, or performance. Even in these conditions the response showed high robustness due to large plant parameters variations and a reasonable noise filtering. Responses fails when the dead time, due to sample-hold circuits,optical sensor, and computer tasks, is increased. Limiting value found for the parameter was 0.2 second. It is sufficient to degenerate the system performance. Implications in to lower the dead time are related to rising the costs of the instrument. More expressive results are outlined in graphics followed by discussions. MenosCell turgor (plant intracellular pressure) is a parameter very know by physiologists and its determination is fundamental for the evaluation of water relations of higher (multicellular) plants. It is largely used in studies of plant tolerance or resistance to various stresses caused by irregular supply of nutrients, water and some other factors required by plant organism. The determination of cell turgor is also important for the development of models for water transport in plant tissues. Although this matter is of great importance to the physiologists, there are a few papers discribing realistic techniques for this purpose. Basically, the most reliable developed devices consisted of capillary filled with oil. It was used to puncture a plant cell and the meniscus moved itself according to the intracellular pressure. A hydraulic apparatus driven by a DC motor was used for counteracting the cell fissure, impelling pressure in the sense of the plant cell. The effort dispensed by the motor was correlated with the cell pressure. In a previous paper we have applied by the first time a control system approach to this problem. It was possible to determine the feasible work ranges, stability conditions, performance. The hydraulic system plus the DC motor was changed by external controlled temperature acting over the capillary wall. However the meniscus position detection was exposed to ambient temperature causing noisy measurement. In order to overcome this problem we propose in this... Mostrar Tudo |
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Palavras-Chave: |
Agricultural instrumentation; Controlador PI; Instrumentacao agropecuaria; LQG; LQR; Medida; Pressao intracelular; Pressure probe. |
|
Thesaurus NAL: |
measurement; turgor. |
|
Categoria do assunto: |
-- |
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Marc: |
LEADER 03531naa a2200301 a 4500
001 1027336
005 2010-08-24
008 1999 bl uuuu u00u1 u #d
020 $a960-8052-12-2
100 1 $aBERTUCCI-NETO, V.
245 $aControl systems-based design of a plant intracellular pressure measurement instrument.
260 $c1999
300 $ap. 199-203.
520 $aCell turgor (plant intracellular pressure) is a parameter very know by physiologists and its determination is fundamental for the evaluation of water relations of higher (multicellular) plants. It is largely used in studies of plant tolerance or resistance to various stresses caused by irregular supply of nutrients, water and some other factors required by plant organism. The determination of cell turgor is also important for the development of models for water transport in plant tissues. Although this matter is of great importance to the physiologists, there are a few papers discribing realistic techniques for this purpose. Basically, the most reliable developed devices consisted of capillary filled with oil. It was used to puncture a plant cell and the meniscus moved itself according to the intracellular pressure. A hydraulic apparatus driven by a DC motor was used for counteracting the cell fissure, impelling pressure in the sense of the plant cell. The effort dispensed by the motor was correlated with the cell pressure. In a previous paper we have applied by the first time a control system approach to this problem. It was possible to determine the feasible work ranges, stability conditions, performance. The hydraulic system plus the DC motor was changed by external controlled temperature acting over the capillary wall. However the meniscus position detection was exposed to ambient temperature causing noisy measurement. In order to overcome this problem we propose in this paper a new design based on Linear Quadratic methods, specifically Proportional plus Integral Estimators in conjunction with Proportional Plus Integral State Feedback Regulator Designs. Main idea is to profit by the robustness characteristics of a PI controller together with the setting of the filter bandwidths for good noise filtering and transient responses. Morover, PI estimator can be optimum for a plant process noise which is high in intensity at low frequencies. The system was modeled and simulations were performed using parameters in limit conditions either of stability, or performance. Even in these conditions the response showed high robustness due to large plant parameters variations and a reasonable noise filtering. Responses fails when the dead time, due to sample-hold circuits,optical sensor, and computer tasks, is increased. Limiting value found for the parameter was 0.2 second. It is sufficient to degenerate the system performance. Implications in to lower the dead time are related to rising the costs of the instrument. More expressive results are outlined in graphics followed by discussions.
650 $ameasurement
650 $aturgor
653 $aAgricultural instrumentation
653 $aControlador PI
653 $aInstrumentacao agropecuaria
653 $aLQG
653 $aLQR
653 $aMedida
653 $aPressao intracelular
653 $aPressure probe
700 1 $aPESSOA, J. D. C.
700 1 $aCRUVINEL, P. E.
700 1 $aCALBO, A. G.
773 $tIn: MASTORAKIS, N. E. (Ed.). Computers and computational engineering in control. [Athens]: World Scientific and Engineering Society, 1999.
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