Emitter discharge variability of subsurface drip irrigation in uniform soils: effect on water-application uniformity

Emitter discharge of subsurface drip irrigation (SDI) decreases as a result of the overpressure in the soil water at the discharge orifice. In this paper, the variation in dripper discharge in SDI laterals is studied. First, the emitter coefficient of flow variation CVq was measured in laboratory experiments with drippers of 2 and 4 L/h that were laid both on the soil and beneath it. Additionally, the soil pressure coefficient of variation CVhs was measured in buried emitters. Then, the irrigation uniformity was simulated in SDI and surface irrigation laterals under the same operating conditions and uniform soils; sandy and loamy. CVq was similar for the compensating models of both the surface and subsurface emitters. However, CVq decreased for the 2-L/h non-compensating model in the loamy soil. This shows a possible self-regulation of non-compensating emitter discharge in SDI, due to the interaction between effects of emitter discharge and soil pressure. This resulted in the irrigation uniformity of SDI non-compensating emitters to be greater than surface drip irrigation. The uniformity with pressure-compensating emitters would be similar in both cases, provided the overpressures in SDI are less than or equal to the compensation range lower limit

Receptividad estigmática en manzano (Malus x pumila, Mill.)

Panel(S5-P7) presentado en la Reunión de la Sociedad Española de Fisiología Vegetal (SEFV) (18ª. Zaragoza. 8-11 septiembre 2009).La receptividad estigmática es un parámetro floral que determina el tiempo en el que los estigmas mantienen la capacidad de generar un ambiente propicio para la germinación de los granos de polen. Este parámetro afecta directamente al éxito reproductivo y tiene especial relevancia en especies cultivadas en las que tiene una clara repercusión en la cosecha. A pesar de su relevancia, se desconocen los factores determinantes de la receptividad estigmática. En este trabajo se estudia la receptividad estigmática en manzano (Malus xpumila, Mill.). Para ello se ha evaluado el momento en que se adquiere la receptividad estigmática observando los cambios en los tejidos del estigma, así como el comportamiento del polen tras su llegada a la superficie estigmática. Con este propósito se han realizado fijaciones secuenciales de los estilos para la observación de cambios histoquímicos en diversos estados de desarrollo previos a la apertura floral. Del mismo modo, se han observado cambios producidos por la polinización en las células estigmáticas. Finalmente, y tras observaciones secuenciales en el tiempo, se ha evaluado el comportamiento de los granos de polen en el estigma tras la polinización. Los resultados permiten establecer el marco espacio temporal en el cual las flores del manzano son receptivas, así como los cambios en las células que acompañan la adquisición de la receptividad y apoyan la interacción polen-estigma.Este estudio ha sido financiado, con CICYT AGL2006-13529-C02-O1, por una beca FPI a Juan M. Losada y por el Grupo de Excelencia de Aragón A-43.Peer reviewe

El perfil del profesorado universitario : un profesional en evolución constante

En este trabajo presentamos los resultados de una investigación que ha sido desarrollada en la Universidad de Huelva (España). Actualmente en España se están desarrollando una gran cantidad de estudios e investigaciones en los campos de la evaluación, la formación, la investigación o la innovación. Ello se debe a la preocupación por la mejora de la calidad de la institución universitaria, y por otro a los procesos de certificación y acreditación a los que se está sometiendo a las universidades, su personal y los servicios que afrece, como consecuencia del proceso de convergencia europea. En este sentido, la aplicación masiva de procesos evaluadores está teniendo fuertes consecuencias sobre la institución superior de enseñanza y sobre su calidad, ya que las decisiones políticas se adoptan en función de los resultados obtenidos.______________________________This paper aims to show the results of a research which has been carried out by the University of Huelva in Spain. A large number of articles on assessment, training, scientific research and innovation are been developed nowadays in Spain. This is mainly due to different facts. On the one hand a growing interest in improving quality of University as an institution. On the other hand, because of the procedures university staff has to develop to prove its worth and the services (faculties offer as part of an institution). This is a result of the European Convergence Process. The huge implementation of assessment and appraisal procedures has had a great influence on University and its quality because political decisions are made according to its results. University teachers are the most affected and we aim at depicting how they define their professional profile and their permanent training so as to snake a sharp portrait of where they stand on this issue. These contributions are part of a larger research. We will focus on the conclusions and give a brief description of some methodological aspects and relevant results

The influence of the progamic phase for fruiting in the apple tree

24 p., 12 fig., 6 tabl. The definitive version is available at http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1744-7348Final fruit production is the result of a number of processes, over which several environmental circumstances interact. But it is often difficult to disentangle the part played by each of these factors in the final crop. The aim of this work is to evaluate the influence of the progamic phase for fruiting in the apple tree. For this purpose we track back the process that goes from flower to fruit, identifying the inflection points where the final crop is reduced. We evaluate early versus late fruit development, pollination versus non-pollination, and the effect of the progamic phase that goes from pollination to fertilization. From flowers to fruits 15 weeks elapsed, but the final fruit set settled 8 weeks after flowering, and the main flower–fruit drop occurred 3–4 weeks after flowering. Differences between dropped fruits and those that remained in the tree emerged earlier, and the onset of fruiting started 7 days after pollination. This time was coincident with the time lapse of the progamic phase. These results show that fruiting gets established well ahead of cropping, but also that the progamic phase is the main determinant of the final fruit set in apple trees.This work was supported by Ministerio de Ciencia e Innovación (MICINN)-FEDER[AGL2006-13529-C02-01, AGL 12621-C02-01 and AGL 2012–40239] and Gobierno de Aragón [group A43]. J. M. L. was supported by a FPI fellowship [BES-2007-16059] from the MICINN.Peer reviewe

A New Methodology for Assessing the Interaction between the Mediterranean Olive Agro-Forest and the Atmospheric Surface Boundary Layer

Historically, the olive grove has been one of the most emblematic ecosystems in Mediterranean countries. Currently, in Andalusia, Spain, the land under olive grove cultivation exceeds 1.5 million hectares, approximately 17% of the regional surface. Its exploitation has traditionally been based on the use of the available land and heterogeneous plantations, with different species adapted to southern Mediterranean climatic conditions, and to the management of the traditional olive cultivation culture. The objective of this work is to characterize the mechanical behavior of the atmospheric surface boundary layer (SBL) (under neutral stability) interacting with different olive grove configurations. Experimental tests were carried out in the Boundary Layer Wind Tunnel (BLWT) of the Andalusian Institute for Earth System Research (IISTA), University of Granada. Three representative configurations of olive groves under neutral atmospheric conditions were tested. The wind flow time series were recorded at several distances and heights downwind the olive plantation models with a cross hot wire anemometry system. Herein, this paper shows the airflow streamwise, including the mean flow and the turbulent characteristics. The spatial variability of these two mechanical magnitudes depends on, among others, the size, the agro-forest length, the layout of the tree rows, the porosity, the tree height, the crown shape and the surface vegetation cover. The aerodynamic diameter and Reynolds number for each agro-forest management unit are proposed as representative variables of the system response, as these could be related to olive grove management. The plantation, in turn, conforms to a windbreak, which affects the microclimate and benefits the elements of the ecosystem. Detailed knowledge of these variables and the interaction between the ecosystem and the atmosphere is relevant to optimize the resources management, land use and sustainability of the overall crop. Thus, this paper presents preliminary work to relate atmospheric variables to environmental variables, some of which could be humidity, erosion, evapotranspiration or pollen dispersion.“Proyectos de Investigación Precompetitivos para Jóvenes Investigadores” from the University of Granad

Wave Breaker Types on a Smooth and Impermeable 1:10 Slope

This research identified the types of wave breaker on a non-overtoppable, smooth and impermeable 1:10 slope under regular waves. Experimental tests were carried out in the Atmosphere-Ocean Interaction Flume of the Andalusian Institute for Earth System Research (University of Granada). Using the experimental space [log(h/L)–log(H/L)] and the alternate slope similarity parameter [χ = log (h/L H/L)], a complete set of breaker types was identified. Four types of wave breaker were then added to Galvin’s classification. Our results showed that the value of the Iribarren number was not sufficient to predict the expected type of wave breaker on the slope. Except for spilling and early plunging breakers, no biunivocal relationship was found between Ir and the type of breaker. The data obtained in the physical model were further enriched with the results of the flow characteristics and the wave energy transformation coefficients obtained with the IH-2VOF numerical model on a 1:10 impermeable slope. This research study, presented in this paper, showed that the Iribarren number is not a convenient wave breaking similarity parameter.This research was supported by the research group TEP-209 (Junta de Andalucía) and by two projects: (1) “Protection of coastal urban fronts against global warming–PROTOCOL” (917PTE0538), (2) “Integrated verification of the hydrodynamic and structural behavior of a breakwater and its implications on the investment project–VIVALDI” (BIA2015-65598-P) and (3) “Laboratory testing and knowledge transfer for the development of sustainable strategies for marine energy harvesting (SUSME)” (PCI2019-103565)

Extending an Application-Level Checkpointing Tool to Provide Fault Tolerance Support to OpenMP Applications

[Abstract] Despite the increasing popularity of shared-memory systems, there is a lack of tools for providing fault tolerance support to shared-memory applications. CPPC (ComPiler for Portable Checkpointing) is an application-level checkpointing tool focused on the insertion of fault tolerance into long-running MPI applications. This paper presents an extension to CPPC to allow the checkpointing of OpenMP applications. The proposed solution maintains the main characteristics of CPPC: portability and reduced checkpoint file size. The performance of the proposal is evaluated using the OpenMP NAS Parallel Benchmarks showing that most of the applications present small checkpoint overheads.Ministerio de Economía y Competitividad; TIN2013-42148-

Carbon allocation dynamics one decade after afforestation with Pinus radiata D. Don and Betula alba L. under two stand densities in NW Spain

Silvopastoral systems can contribute to the mitigation of climate change by functioning as sinks for greenhouse gases better than exclusively agricultural systems. Tree species, density, and an adequate management of the pasture carrying capacity contribute to the capacity of carbon sequestration. In this study, the capacities for carbon sequestration in silvopastoral systems that were established with two different forest species (Pinus radiata D. Don and Betula alba L.) and at two distinct densities (833 and 2500 trees ha−1) were evaluated. Tree, litterfall, pasture and soil carbon storage determinations were carried out to deliver carbon sequestration in the different pools within the first 11 years of a plantation establishment. The results show that the global capacity for carbon sequestration in silvopastoral systems with pine canopy was higher than with birch cover. Independently of the forest species, the capacity for carbon sequestration increased when the systems were established at higher plantation densities. There were found strong differences in the relative proportions of carbon in each component of the system (litterfall, tree, pasture and soil). The soil component was found to be most important in the case of the broadleaf forest established at low density. The establishment of a silvopastoral system enhanced soil carbon storage, since afforestation was carried out, which results in a more enduring storage capacity compared with treeless areas.Spanish Ministry and Xunta de Galici

Tsunami wave interaction with mangrove forests: A 3-D numerical approach

ABSTRACT: A three dimensional numerical approach based on IHFOAM to study the interaction of tsunami waves with mangrove forest is presented. As a first approximation, the problem is modelled by means of solitary waves impinging on emergent rigid cylinders. Two different conceptual approaches are implemented into IHFOAM. Solving the URANS equations provides a direct simulation of the flow field considering the actual geometry of the array of cylinders. A modified version of the volume-average URANS equations by introducing a drag force to model the momentum damping created by the cylinders is used in the second approach. Both the direct and macroscopic simulations are validated against laboratory experiments for wave damping with very high agreement. A large set of numerical experiments to analyse flow parameters and uniform and random cylinder array distributions are analysed and use to compare pros and cons of the different approaches. Large differences are found in the forces exerted on the vegetation for uniform and random distributions. Generalizations obtained from uniform arrangements could lead to underestimation of wave-exerted forces, especially for low dense configurations. Wave forces calculated with the macroscopic approach by means of the drag coefficient yields clear underestimations.M. Maza is indebted to the MEC (Ministerio de Educación, Cultura y Deporte, Spain) for the funding provided in the FPU (Formación del Profesorado Universitario) studentship (BOE-A-2012-6238). This work has been partially funded under the RETOS program of the Spanish Ministry of Economy and Competitiveness (BIA2014-59718)