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| Bomfim,Guilherme V. do; Manzano,Juan; Azevedo,Benito M. de; Vasconcelos,Denise V.; Viana,Thales V. de A.. |
| The purpose of this research was to evaluate the K2O distribution uniformity by surface drip irrigation at Universitat Politecnica de Valencia, Valencia, Spain (39º 29′ N, 0º 23′ W, 20 m). The irrigation was performed by drip lines with not-compensated emitters, spaced 0.3 m. The fertigation was realized using a fertilizer injector pump of electric action with injection of 0.25 h. The experimental design used completely randomized blocks with five treatments and four replications. The treatments consisted of injection in five distances, located at 10; 20; 30; 40; 50 m of the first drip line. Samples were collected in emitters located at the start, at 1/3, at 2/3 and at the end of the drip lines. The nutrient concentration was determined by flame... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Uniformity; Chemigation; K2O. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000600011 |
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| Manzano,Juan; Palau,Carmen V.; Benito,M. de Azevedo; Guilherme,V. do Bomfim; Vasconcelos,Denise V.. |
| ABSTRACT To determine the influence of geometry on the hydrodynamic behavior of Venturi injectors, using computational fluid dynamics techniques, we studied, at the Universitat Politècnica de València, Valencia, Spain, the geometric parameters that exert the most influence on head losses: the relationship between throat diameter and nozzle (β), nozzle angle (α1) and diffuser angle (α2). In addition, three throat morphologies (B1: nozzle-throat and throat-diffuser with a sharp edge; B2: nozzle-diffuser with a zero-length, sharp-edge throat; B3: nozzle-throat and throat-diffuser with rounded edge). We analyzed their influence on the velocity distribution and differential pressure between inlet and throat (DP/γ), throat and outlet (Δhv/γ), and outlet and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemigation; Fertirrigation; DFC. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000300482 |
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| Manzano,Juan; Azevedo,Benito M. de; Bomfim,Guilherme V. do; Royuela,Álvaro; Palau,Carmen V.; Viana,Thales V. de A.. |
| En la Universitat Politècnica de València, Valencia, España, se ha estudiado el diseño y funcionamiento de cuatro prototipos del inyector Venturi con técnicas de Dinámica de Fluidos Computacional (CFD), comparándo las con ensayos en laboratorio. Para cada prototipo, las geometrías definidas y analizadas han permitido simular el funcionamiento sin (G1) y con inyección (G2) para quimigación. En el caso G1, se presentan los gráficos del perfil de presiones en el eje del inyector para diversas velocidades, así como la distribución del campo de presiones y de la evolución de las diferencias de presión y pérdidas de carga frente al caudal principal. Para comparar los resultados obtenidos con CFD frente al resultado experimental, se calculó el error relativo. En... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dinámica de fluidos computacional; RANS; Quimigación. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662014001200002 |
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| Bomfim,Guilherme Vieira do; Azevedo,Benito Moreira de; Viana,Thales Vinícius de Araújo; Manzano,Juan; Vasconcelos,Denise Vieira. |
| RESUMOPara aperfeiçoar o manejo fitossanitário de pragas na cultura do melão (Cucumis melo L.), objetivou-se avaliar os efeitos de formas de aplicação e doses de inseticidas sobre a eficiência de controle químico do pulgão A. gossypii. O experimento foi realizado em 2010, na cidade de Fortaleza, Ceará, com melão amarelo cultivado em condições de campo. O delineamento experimental foi em blocos ao acaso, arranjo fatorial 2 x 4, com quatro repetições e parcelas de seis plantas. Os tratamentos foram duas formas de aplicação (pulverização costal manual e insetigação por gotejamento) e quatro doses de inseticida (0; 50; 100; 200% da dose recomendada pelo fabricante). Os inseticidas acefato e tiametoxam, testados separadamente, foram aplicados em manejo de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cucumis melo L.; Pulgão; Pulverização foliar; Quimigação. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902015000300488 |
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| Manzano,Juan; Palau,Carmen Virginia; Azevedo,Benito Moreira de; Bomfim,Guilherme Vieira do; Vasconcelos,Denise Vieira. |
| ABSTRACT Venturi-type chemigation injectors are widely used due to their advantages: they do not require electric power and are cheap to operate. However, they also generate considerable energy losses which affect the pressure in the system. The correct characterization of these systems requires pressures to be correctly set at the inlet, injector and outlet points in relation to main and injected solution flows. These analytical relationships, as described in the International Organization for Standardization’s standard ISO 15873:2002, can be obtained theoretically, although it is recommended that the manufacturer should determine the real behavior of the injector by operational tests. These relationships should also be provided graphically in the form of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemigation; Fertigation; Head losses; Nomography. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000200201 |
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| Manzano,Juan; Palau,Carmen Virginia; Azevedo,Benito Moreira de; Bomfim,Guilherme Vieira do; Vasconcelos,Denise Vieira. |
| En la UniversitatPolitécnica de València, Valencia, Espana (39°29' N; 0°23' W; 20 m), ha sido estudiado el funcionamiento de cuatro prototipos de inyector Venturi y tres formas de instalación distintas. El funcionamiento se ha analizado bajo diversos parâmetros, como pérdidas de carga, relación de caudales y rendimiento. Las formas de instalación analizadas han sido: sin inyección y con inyección y presiones negativas o positivas en la garganta. Las presiones se establecieron entre 10 y 40 m.c.a. A partir de los datos experimentales han sido procesados utilizando técnicas de regresión múltiple y análisis de la varianza. Con ellas, fue posible, a través de la integración de geometrías en función de los diâmetros, caudales y presiones, obtener expresiones... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Riego presurizado; Quimigación; Fertirigación. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902015000200287 |
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| Palau,Carmen Virginia; Arviza,Jaime; Balbastre,Iban; Manzano,Juan. |
| ABSTRACT: DIMSUB is a computer program to complement a decision support tool (DST) to effectively study different hydraulic design alternatives in microirrigation systems. We developed environments in Visual Basic for applications for Microsoft Excel® that allow specific step-by-step functions to be created for the design of irrigation subunits. Different alternatives can be considered, such as types of emitter, lateral and submain pipe sizes, different feeding points, irregular subunit shapes and topography slopes. Furthermore, specific uniformity criteria need to be considered to achieve efficient water applications and proper design systems. Lengths of run lateral and submain pipes, position of the hydrant connection, pressure head and head loss in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Irrigation; Emission uniformity; Dripper; Manifold. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000300100 |
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