Search results for " DRIP"
showing 10 items of 39 documents
Linking the Kinetic Energy Fraction and Equivalent Length Method for Trickle Irrigation Design under Local Losses
2020
New methods using analytical relationships to design drip irrigation laterals and subunits have been introduced in recent years based on the assumption that minor losses can be neglected. This assumption could be relaxed by applying the equivalent method, which makes it possible to account for minor losses, such as those caused by emitter connections, through formulas based on the rationale that an equivalent length of the drip lateral produces the same losses. However, equivalent length formulas are empirical; thus, they do not necessarily cover the entire range of conditions in the real-world contexts in which the formulas will be applied, and their extrapolation could lead to erroneous r…
Using HYDRUS-2D model to assess the optimal drip lateral depth for eggplant crop in a sandy loam soil of central Tunisia
2016
The main objective of the work is to assess the optimal drip lateral depth for Eggplant crop (Solanum melongena L.) irrigated with a drip system in a sandy loam soil by means of field measurements and simulation models. Initially, the performance of Hydrus-2D was assessed based on the comparison between simulated soil water contents (SWC) and the corresponding measured in two plots, in which laterals with co-extruded emitters were laid on the soil surface (drip irrigation, DI-0) and at 20 cm depth (subsurface drip irrigation, SDI-20), respectively. In order to identify the optimal position of the lateral, the results of different scenarios, obtained by changing the installation depth of the…
Salso-bromo-iodine thermal water: a nonpharmacological alternative treatment for postnasal drip-related cough in children with upper respiratory trac…
2018
Postnasal drip (PND)-related cough is a very common symptom in patients with upper respiratory tract infections (URTis). At present, there is not a standard treatment for postnasal drip and postnasal drip-related cough. The aim of this pilot study was to evaluate the efficacy of a specific salso-bromoiodine thermal water containing hyaluronic acid and grapefruit seed extract (SBI-H-GSE) comparing it with a normal saline solution in children with URTis who refer PND-related symptoms. The study was randomized, single-blind, and controlled. Study group (75 children) was treated with SBI-HGSE and control group (65 children) was treated with a normal saline solution; both compounds were administ…
Optimizing subsurface dripline installation depth with Hydrus 2D/3D to improve irrigation water use efficiency in the central Tunisia
2015
The main objective of the work is to optimize drip installation depth for Eggplant crop irrigated with surface or subsurface drip irrigation systems to improve irrigation Water Use Effeciency (WUE), by means of field measurements and simulations carried out with Hydrus-2D model. Initially, a comparison between simulated Soil Water Contents (SWC) and the corresponding measured in two plots, in which laterals with coextruded emitters are laid on the soil surface (T0) and at 20 cm depth (T20), respectively. In order to choose the best position of the lateral, the results of different simulation run, carried out by choosing a deeper installation (T45) depth. Simulated SWC’s resulted fairly clos…
Subsurface Drip Irrigation and ICT for the Innovative Irrigation Water Management: Application to a Citrus Crop (C. reticulata cv. Tardivo di Ciacull…
2020
Subsurface drip irrigation (SDI) is considered one of the most efficient irrigation systems because it allows the optimization of crop water productivity maximizing, at the same time, farmers’ economic benefit. However, to take full advantage of SDI systems it is necessary to prevent emitter obstructions caused by root intrusion, as well as to apply water-saving strategies, such as regulated deficit irrigation (RDI). Regarding the first aspect, manufacturers are claiming different techniques to protect emitters from root intrusion, such as mechanical barriers, addition with different chemical compounds into the emitter itself or chemicals into irrigation water. On the other hand, the applic…
THE EFFECTS OF IRRIGATION WATER AS A FUNCTION OF THE DISTANCE BETWEEN IRRIGATION DRIPPERS IN A TOMATO FIELD.
2014
The growth and the yield of the tomato plant in southern hot-arid areas of Italy, depending on the satisfaction of water needs. The aim is to evaluate the effect of the distance between drippers on the marketable yield of tomatoes because the installation depend mainly on the number of drippers. Were compared 4 dripper intervals: 15, 30, 60 and 90 cm. The results show that the distance between the drippers must be determined according to the hydraulic characteristics of the soil. In soils with a clay matrix characterized by a low infiltration rate, it seems useful to position the drippers at a distance between 60 and 90 cm.
Using Hydrus 2-D Simulation model to evaluate wetted soil volume in subsurface drip irrigation systems.
2007
Drip irrigation is considered one of the most efficient irrigation systems. Alternatively to the traditional drip irrigation systems, laterals can be installed below the soil surface. Realizing the subsurface drip irrigation (SDI), which recently has been increasing in use as a consequence of advances in plastics technology, making SDI equipment more affordable and long lasting. Due to its potential high efficiency SDI may produce benefits, especially in places where water is a limited source. As the use of SDI is relatively new, a better understanding of the infiltration process around a buried point source can contribute to increased water use efficiency and consequently the success of dr…
Probing Surface Quantum Flows in Deformed Pygmy Dipole Modes
2017
In order to explore the nature of collective modes in weakly bound nuclei, we have investigated deformation effects and surface flow patterns of isovector dipole modes in a shape-coexisting nucleus $^{40}$Mg. The calculations were done in a fully self-consistent continuum finite-amplitude Quasiparticle Random Phase Approximation (QRPA) in a large deformed spatial mesh. An unexpected result of pygmy and giant dipole modes having disproportionate deformation splittings in strength functions was obtained. Furthermore, the transition current densities demonstrate that the long-sought core-halo oscillation in pygmy resonances is collective and compressional, corresponding to the lowest excitatio…
Laser spectroscopy and the properties of light nuclei near the neutron drip line
1993
The interesting nuclear structure phenomena observed in some light nuclei at the neutron drip line suggest the measurement of basic ground state properties such as spins, magnetic moments and electric quadrupole moments. Here it will be discussed what experiments are presently feasable using laser spectroscopy. For the outstanding example of a “halo” nucleus,11Li, the development of a technique combining β-asymmetry detected optical pumping in a fast beam with NMR spectroscopy has yielded pertinent results, the most recent of which is an experimental value of the nuclear quadrupole moment.
Beta-decay half-lives of very neutron-rich nuclei and their consequences for the astrophysical r-process
2005
Half-lives for Gamow-Teller β-decay of very neutron-rich nuclei have been calculated using the RPA shell-model code of Krumlinde and Muller. For the examples of the isotope sequences of 27Co and 37Rb, and of nuclei around 132Sn it is demonstrated that close agreement between experiment and theory can be obtained, provided an appropriate choice of model parameters is made for each mass region. On the basis of this agreement, T1/2 predictions for isotopes up to the r-process path are made and compared to earlier model calculations. Possible implications of the results on the site and the cycle time of the r-process are discussed.