A novel approach for the design of drip irrigation systems is presented. The diameters of the laterals and submains were calculated by minimising an objective cost function that includes investment and operating costs of drip irrigation units. Diameters, head loss and its distribution between laterals and submain, average operating pressure head, upstream end energy head and the distribution uniformity were all deduced from an economic approach. These variables are not matched alone but are the consequence of the economic optimisation. Several examples with self-compensating and non-compensating emitters fed from either a pump station or a water reservoir are presented to illustrate the feasibility of the proposed methodology.
Evaluation methods for functioning drip irrigation units are proposed to determine the hydraulic characteristics of emitters and pipelines. The aim of the study was to characterize the discharge curve of the emitters, their coefficient of variation, and the head losses in laterals and submains. In the laboratory, four laterals were tested under a wider range of pressure heads than the typical values of field installations. In additional, a field irrigation unit was evaluated. The discharge curve and coefficient of variation were determined in the unit with an accuracy similar to that obtained from laboratory experiments. For self-compensating emitters, a constant flow rate above the lower limit of the compensating range and an orifice-type discharge curve below that limit are proposed. For non-compensating emitters, an orifice-type discharge curve, with exponent x = 0.5, except for specific cases, is proposed. The manufacturing coefficient of variation was independent of pressure and relatively low for all the analysed emitters. Regarding the parameters of the local head losses, the equivalent length le presented values more independent of the flow than coefficient K. For the characterisation of laterals with selfcompensating emitters, it is recommended to measure with the downstream end open to reduce the uncertainty in the experiments. The results show that the unit can be operated so that the average discharged flow and the uniformity can be matched just controlling the pressure head at upstream end point of the unit.
Dentro de la práctica clínica asistencial de enfermería, existen diferentes factores que dificultan la detección de las reacciones adversas producidas por los fármacos. La farmacovigilancia es utilizada para la prevención de riesgos de los medicamentos en los diferentes pacientes, y evitar los costes económicos que estos representan. Esta vigilancia en el marco de la práctica habitual se realiza por los sistemas de farmacovigilancia, dispuestos para cada país, ya que las presencias de las reacciones adversas a medicamentos pueden estar asociados a diferentes causas relacionadas al paciente como también, a la adquisición y distribución farmacológica. Teniendo en cuenta la baja incidencia de reportes de reacciones adversas por parte del personal de enfermería en las diferentes instituciones hospitalarias, se debe mantener una comunicación asertiva y continua capacitación al personal de enfermería para llevar a cabo el programa de farmacovigilancia dentro de las unidades de salud, y así disminuir el crecimiento de la mortalidad a causa de la misma.
<p>Se analizan y proponen métodos de evaluación para determinar en campo la ecuación en gasto del emisor, las pérdidas de carga en ramales y porta-ramal y la uniformidad de distribución. Se han ensayado con ocho ramales y una unidad en campo a diferentes presiones. Los resultados muestran que es posible determinar la curva de gasto y coeficiente de variación de manufactura con una precisión similar a la del método normalizado, pudiendo ser más representativa en la instalación real. En cuanto a la caracterización de pérdidas, la longitud equivalente presentó valores más independientes del caudal que el coeficiente K que multiplica al sumando cinético. En unidades, y ramales, es posible observar el efecto de la presión de entrada en la uniformidad y, así, seleccionarla considerando también el coste de energía. Se concluye que los métodos propuestos permiten caracterizar la respuesta hidráulica de ramales, porta-ramales y del riego de la unidad.</p>
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