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Recent Submissions

Analysis of Water Application with Semi-Portable Big Size Sprinkler Irrigation Systems in Semi-Arid Areas
(Elsevier, 2016) Sheikhesmaeili , Omid; Laserna Arcas, Santiago eduardo; Montero Martínez, Jesús
Sustainability of irrigated agriculture depends heavily on getting a high efficiency application for theirrigation. It is very important to understand the factors that affect to irrigation uniformity and dischargeefficiency, especially using semi-portable big size sprinkler. There are not studies conducted with big sizesprinklers which work on high flow rates and big layouts spacing. In this paper, the spray losses (Ls) andwater distribution of sprinkler irrigation system with semi-portable big size sprinkler on semi-arid areashave been characterized. The factors affecting on discharge efficiency and irrigation uniformity wereanalysed (working pressure, irrigation layout and weather conditions). The field tests were conductedin outdoor conditions with a single sprinkler system. Six predictive equations were obtained to estimatedrift and evaporation losses. The proposed equations use operating pressure, wind speed and vapourpressure deficit. The results show an increment of 3.26% for Ls for each increment of 1 m s1of windspeed. Spray losses rise up to 22.7% at 450 kPa operating pressure when wind speed and vapour pressuredeficit increased up to 4.2 m s1and 6 kPa, respectively. A significantly effect of wind is appreciated on thespray losses and water distribution pattern under different conditions with regard for working pressureand sprinkler spacing. This behaviour is very similar to obtained with medium size sprinklers. Technicalcriteria can be used to optimize irrigation management according to the design factors and the climatic parameters.
Algunas propuestas de actualización de contenidos gramaticales a partir de dos obras de referencia académicas
(2024) Horno Chéliz, M. carmen; Carrasco Gutiérrez, María Ángeles
Enhancement of SO2 high temperature depolarized electrolysis by means of graphene oxide composite polybenzimidazole membranes
(ELSEVIER SCI LTD, 2022) Díaz Abad, Sergio; Fernández Mancebo, Sandra; Rodrigo Rodrigo, Manuel Andrés; Lobato Bajo, Justo
In the present work, Polybenzimidazole-composite membranes with graphene oxide as organic filler with different contents (0.5, 1.0, 2.0 and 3.0 wt%) were prepared and tested in a sulfur depolarized electrolyzer. The composite Graphene Oxide/Polybenzimidazole membranes show greater electrolyzer performance than a standard membrane. For the first time, actual hydrogen production is reported at high temperature in the range of 110 °C–140 °C for the sulfur dioxide depolarized electrolysis. In general, composite Graphene Oxide/Polybenzimidazole membranes showed superior performance, obtaining the highest hydrogen generation with the composite membrane with a content of 2 wt%. Furthermore, sulfur dioxide crossover is reported to decrease by increasing the amount of graphene oxide into the membrane, demonstrating the benefit of adding Graphene Oxide to a Polybenzimidazole matrix for the sulfur dioxide depolarized electrolysis.
Enhancement of the Green H2 Production by Using TiO2 Composite Polybenzimidazole Membranes
(MDPI, 2022) Díaz Abad, Sergio; Rodrigo Rodrigo, Manuel Andrés; Sáez Jiménez, Cristina; Lobato Bajo, Justo
This study reports the hydrogen production using TiO2 based composite polybenzimidazole membranes through the SO2 depolarized electrolysis that requires lower energy input than the direct water electrolysis. Composite membranes prepared and studied in this work showed very promising results in terms of proton conductivity, chemical stability, and crossover. Thus, a reduction in SO2 crossover was observed with the increase of the concentration of TiO2, obtaining reductions as high as 42% with the 3.0 wt% TiO2-PBI membrane at 120 °C. Higher hydrogen production rates and Faradaic efficiencies were achieved by all the composite membranes, with an optimum for the 1.0 wt% TiO2-PBI membrane (with this membrane, the production of hydrogen increased a 53% at 110 °C and a 49% at 120 °C as compared with the standard PBI membrane), demonstrated the benefit of the use of composite membranes with respect to the standard one for green hydrogen production.
A new hyperaccumulator plant (Spergularia rubra) for the decontamination of mine tailings through electrokinetic-assisted phytoextraction
(Elsevier, 2024) Medina Díaz, Hassay lizeth; López-Bellido Garrido, Francisco Javier; Alonso Azcárate, Jacinto; Fernández Morales, Francisco Jesús; Rodríguez Romero, Luis
The screening of new effective metal hyperaccumulators is essential for the development of profitable phytoremediation projects in highly degraded environments such as mining areas. The goal of this research was to analyze the phytoextraction potential of the native plant Spergularia rubra to decontaminate and eventually recover metals (phytomining) from the mine tailings (belonging to an abandoned Pb/Zn Spanish mine) in which it grows spontaneously. To do so, the ability of this plant species to accumulate metals was evaluated both under natural conditions and through simple and electrokinetically assisted phytoextraction tests using alternating current and different combinations of voltage gradient (1/2 V cm-1) and application time (6/12 h per day). The complete duration of the greenhouse trial was 64 days, although alternating current was applied only during the last 14 days. The results obtained demonstrated the exceptional effectiveness of S. rubra for metal hyperaccumulation and growth without affecting toxicity in highly contaminated mining waste. Zn was the metal accumulated to a higher extent in the shoots, reaching concentrations up to 17,800 mg kg-1; Pb was mainly accumulated in the roots reaching a maximum concentration of 8709 mg kg-1. Cu and Cd were accumulated to a lesser extent but the bioconcentration factors were much >1. It has been proved that S. rubra is a hyperaccumulator species for Zn and Cd both in natural and greenhouse conditions and, very probably, Pb in wild conditions. The application of AC current did not significantly increase metal concentrations in plant tissues but it was able to increase the aerial biomass of S. rubra by 49.8 %. As a result, the phytoextraction yields of all metals were significantly improved as compared to wild conditions (up to 86 % for Zn). It could open new expectations about the economic viability of recovering high-value metals from mine tailings.