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Registros recuperados: 14
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Economic optimization method to design telescope irrigation of multiples outlets REA
Pinto,Marinaldo F.; Camargo,Antonio P. de; Coelho,Rubens D..
In this study is presented an economic optimization method to design telescope irrigation laterals (multidiameter) with regular spaced outlets. The proposed analytical hydraulic solution was validated by means of a pipeline composed of three different diameters. The minimum acquisition cost of the telescope pipeline was determined by an ideal arrangement of lengths and respective diameters for each one of the three segments. The mathematical optimization method based on the Lagrange multipliers provides a strategy for finding the maximum or minimum of a function subject to certain constraints. In this case, the objective function describes the acquisition cost of pipes, and the constraints are determined from hydraulic parameters as length of irrigation...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Conduits in series; Minimum cost; Lagrange multipliers.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000400017
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Modelling head loss along emitting pipes using dimensional analysis REA
Perboni,Acácio; Frizzone,Jose A.; Camargo,Antonio P. de; Pinto,Marinaldo F..
Local head losses must be considered in estimating properly the maximum length of drip irrigation laterals. The aim of this work was to develop a model based on dimensional analysis for calculating head loss along laterals accounting for in-line drippers. Several measurements were performed with 12 models of emitters to obtain the experimental data required for developing and assessing the model. Based on the Camargo & Sentelhas coefficient, the model presented an excellent result in terms of precision and accuracy on estimating head loss. The deviation between estimated and observed values of head loss increased according to the head loss and the maximum deviation reached 0.17 m. The maximum relative error was 33.75% and only 15% of the data set...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Microirrigation; Lateral line; Maximum length.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162015000300442
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Development of a filtration system with high-frequency flow reversal AGRIAMBI
Pinto,Marinaldo F.; Alves,Dinara G.; Saretta,Ezequiel; Camargo,Antonio P. de; Botrel,Tarlei A..
ABSTRACT The aim of this study was to develop a filtration system with high-frequency flow reversal and minimum requirement of water for cleaning routines. The system was developed in the period from 2011 to 2013 and consists of three screen filters and eleven solenoid valves electronically controlled by a controller that operates based on head loss measurements. The following evaluations were carried out: head loss curve as a function of flow rate; filtrating efficiency as a function of solids concentration, frequency of flow reversal and increment in head loss. The experimental design was completely randomized in a factorial scheme with three replicates and two treatment levels for each factor. The filtration efficiency was equal to 98.6% for particles...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Water quality; Emitter clogging; Screen filter.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000400295
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Caracterização hidráulica de tubos porosos oriundos de pneus reciclados utilizados em irrigação subsuperficial AGRIAMBI
Pinto,Marinaldo F.; Camargo,Antonio P. de; Rettore Neto,Osvaldo; Frizzone,José A..
Mesmo diante do apelo ecológico pelo reaproveitamento de resíduos, os produtos de irrigação, como é caso de tubos porosos oriundos de pneus reciclados, devem ser avaliados quanto à sua viabilidade técnica. A caracterização hidráulica é um dos requisitos necessários para tal finalidade além de fornecer dados essenciais ao dimensionamento de sistemas de irrigação. Diante do exposto objetivou-se caracterizar tubos porosos quanto aos fatores perda de carga, vazão em função da pressão e variação de vazão. Foram utilizadas cinco amostras de tubo para determinação da perda de carga e oito para a determinação da curva vazão-pressão e do coeficiente de variação, sendo ensaiados sete níveis de pressão. A perda de carga foi determinada com tubo impermeabilizado e com...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Microirrigação; Vazão; Perda de carga.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662014001100001
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Dripper testing: Application of statistical quality control for measurement system analysis AGRIAMBI
Rocha,Hermes S. da; Marques,Patricia A. A.; Camargo,Antonio P. de; Reis,Douglas L. dos; Silva,Eric A. da; Frizzone,José A..
ABSTRACT Laboratory tests for technical evaluation or irrigation material testing involve the measurement of many variables, as well as monitoring and control of test conditions. This study, carried out in 2016, aimed at using statistical quality control techniques to evaluate results of dripper tests. Exponentially weighted moving average control charts were elaborated, besides capability indices for the measurement of the test pressure and water temperature; and study on repeatability and reproducibility (Gage RR) of flow measurement system using 10 replicates, in three work shifts (morning, afternoon and evening), with 25 emitters. Both the test pressure and water temperature remained stable, with “excellent” performance for the pressure adjustment...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Dripper flow; Statistical process control; Repeatability and repro; Control charts; Stability and capability; For measurement process.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000900587
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An irrigation controller mechanically actuated by soil-water tension: I - Design, development and laboratory evaluations AGRIAMBI
Almeida,Alexsandro C. S.; Botrel,Tarlei A.; Raine,Steven R.; Camargo,Antonio P. de; Pinto,Marinaldo F.; Salvador,Conan A..
ABSTRACT The objective of this study was to develop and evaluate an irrigation controller that was mechanically actuated by soil-water tension within laboratory conditions. The controller was designed and constructed using readily available hydraulic fittings and other componentry. The main components of the controller were a tensiometer; a rubber diaphragm that moves according to the variation in tension inside of the tensiometer; an activation rod that transfers the movement from diaphragm to the switch valve; and a steel spring that regulates the activation of soil water tension. Six irrigation controller samples were tested in the laboratory to evaluate the mechanical performance and component forces required to activate the controllers. The...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Irrigation scheduling; Tensiometer; Automation.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000600369
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Irrigation controller mechanically actuated by soil-water tension: II - Field evaluations AGRIAMBI
Almeida,Alexsandro C. S.; Botrel,Tarlei A.; Raine,Steven R.; Camargo,Antonio P. de; Pinto,Marinaldo F.; Salvador,Conan A..
ABSTRACT In this study, a field evaluation of the performance of an irrigation controller mechanically actuated by soil-water tension (SWT) was performed. The controller employs a tensiometer used as a sensor of SWT to directly control a mechanically actuated hydraulic valve. Six controllers were installed in an orchard to control the irrigation for six rows of plants over 64 days. Each controller controlled the irrigation of one lateral drip line. The drip irrigation system was gravity-fed from a water source placed 7 m above the soil surface. The SWT and the pressure in each lateral line were measured to evaluate the performance of the controllers. All the controllers tested in the field autonomously initiated and terminated the irrigation during the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Irrigation scheduling; Technological innovation; Tensiometer; Automation.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000500298
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Internal surface roughness of plastic pipes for irrigation AGRIAMBI
Rocha,Hermes S. da; Marques,Patricia A. A.; Camargo,Antonio P. de; Frizzone,José A.; Saretta,Ezequiel.
ABSTRACT Assuming that a roughness meter can be successfully employed to measure the roughness on the internal surface of irrigation pipes, this research had the purpose of defining parameters and procedures required to represent the internal surface roughness of plastic pipes used in irrigation. In 2013, the roughness parameter Ra, traditional for the representation of surface irregularities in most situations, and the parameters Rc, Rq, and Ry were estimated based on 350 samples of polyvinyl chloride (PVC) and low-density polyethylene (LDPE) pipes. Pressure losses were determined from experiments carried out in laboratory. Estimations of pressure loss varied significantly according to the roughness parameters (Ra, Rc, Rq, and Ry) and the corresponding...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Friction factor; Head loss; Roughness meter.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000300143
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Characterization of venturi injector using dimensional analysis AGRIAMBI
Sobenko,Luiz R.; Frizzone,José A.; Camargo,Antonio P. de; Saretta,Ezequiel; Rocha,Hermes S. da.
ABSTRACT Venturi injectors are commonly employed for fertigation purposes in agriculture, in which they draw fertilizer from a tank into the irrigation pipeline. The knowledge of the amount of liquid injected by this device is used to ensure an adequate fertigation operation and management. The objectives of this research were (1) to carry out functional tests of Venturi injectors following requirements stated by ISO 15873; and (2) to model the injection rate using dimensional analysis by the Buckingham Pi theorem. Four models of Venturi injectors were submitted to functional tests using clean water as motive and injected fluid. A general model for predicting injection flow rate was proposed and validated. In this model, the injection flow rate depends on...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Buckinghan Pi theorem; Irrigation equipment; Fertigation.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019000700484
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Local head loss caused in connections used in micro-irrigation systems AGRIAMBI
Bombardelli,Wagner W. Á.; Camargo,Antonio P. de; Frizzone,José A.; Lavanholi,Rogério; Rocha,Hermes S. da.
ABSTRACT Information about local head loss caused by connections employed in micro-irrigation systems is hard to be found in literature. The objective of this research was to experimentally determine the local head losses in connections commonly used in micro-irrigation and propose mathematical models using the theorem of Buckingham. The methodology of tests was based on international standards. The tests were carried out under controlled inlet pressure, at 150 kPa, and five to ten units of each connection model were tested. The curves relating flow and head losses were drawn based on 15 flow conditions, obtained under increase and decrease of flow rate. For each condition, 30 points were collected resulting in a sample size of 900 points in each test. For...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Hydraulics; Dimensional analysis; Buckingham Pi theorem.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019000700492
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Flow rate dynamics of pressure-compensating drippers under clogging effect AGRIAMBI
Pinto,Marinaldo F.; Molle,Bruno; Alves,Dinara G.; Ait-Mouheb,Nassim; Camargo,Antonio P. de; Frizzone,José A..
ABSTRACT The clogging dynamics of pressure-compensating drippers is still poorly addressed, and its understanding is quite important to control clogging. The aim of this study was to evaluate the flow performance of pressure-compensating drippers under clogging effect. Eight pressure-compensating emitters, model J-SC Jain PC-PLUS with nominal flow rate of 2.2 L h-1 were evaluated. The tests were run for 8 h d-1 for 4 weeks, a total of 160 h. Every 40 h, the concentration and granulometry of suspended particles were increased, by adding 125 mg L-1 of solids, composed of sand. The flow rate of the emitters was determined using a weight measurement system. Flow rate variations of the emitters did not follow a defined pattern. Clogging seems to occur randomly...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Emitters; Trickle irrigation; Clogging.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000500304
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Development and evaluation of an automated system for testing current meters AGRIAMBI
Saretta,Ezequiel; Camargo,Antonio P. de; Botrel,Tarlei A.; Pinto,Marinaldo F.; Katsurayama,Geancarlo T.; Frizone,José A..
ABSTRACT Current meters are equipment widely used for estimating flow velocity in rivers and streams. Periodic calibrations of current meters are important to ensure the quality of measurements, but the required testing facilities are complex and only available in a few institutions. However, advances in electronics and automation may contribute to developing simple and reliable calibration systems. Thus, this study aimed to develop an automated system for testing current meters, which consisted of a trapezoidal channel, a step motor, a tow car and a management system, composed of a supervisory application and microprocessed modules to control the motor and the data acquisition. Evaluations of the displacement velocity showed that it matched the reference...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Hydrometry; Electronics; Automation; Calibration.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000200181
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Head loss in laser-perforated thin-walled polyethylene pipes for irrigation AGRIAMBI
Melo,Verônica G. M. L. de; Frizzone,José A.; Camargo,Antonio P. de; Bombardelli,Wagner W. Á..
ABSTRACT For reducing fixed and operational costs in pressurized irrigation systems, thin-walled polyethylene pipes with laser-perforated orifices are manufactured to operate under low pressure (up to 100 kPa). Hydraulic characterization of these materials is essential for designing irrigation systems. Considering the material elasticity and the thin wall thickness (about 200 μm), the internal diameter of these pipes may vary according to the operating pressure, resulting in changes of head losses. The purpose of this study was to analyze the head loss in flexible pipes with laser-perforated orifices, and to estimate the maximum length of laterals based on criteria of water distribution uniformity. Non-perforated pipe samples were tested to obtain...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Operating pressure; Diameter change; Design; Lateral line.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019000500317
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Methodology for designing lateral lines with microtubes operated under variable inlet pressure AGRIAMBI
Katsurayama,Geancarlo T.; Saretta,Ezequiel; Camargo,Antonio P. de; Botrel,Tarlei A.; Salvador,Conan A..
ABSTRACT Design of lateral lines consisting of microtubes enables to optimize water distribution uniformity. In addition, there must exist a range of pressures at the lateral line inlet in which the water distribution uniformity remains acceptable. Thus, such emitters are interesting for use in micro-irrigation systems supplied by alternative power sources, in which temporal variability in the electrical power supplied to the pumping systems normally occurs. This study presents a methodology for designing lateral lines with microtubes operated under varying pressure, using the step-by-step method in order to establish the recommended range of lateral line inlet pressures. The proposed methodology was validated over three replicates by testing maximum,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Micro-irrigation; Alternative power sources; Distribution uniformity.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000900594
Registros recuperados: 14
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