62 research outputs found

    Experimental study on the flow-induced vibrations of a circular cylinder with a rear flexibly hinged splitter plate

    Get PDF
    The flow around a circular cylinder is a canonical configuration that may be encountered in many engineering applications, as for instance, civil engineering, architecture, or marine structures. In particular, when bluff bodies are slender and feature low mass-damping characteristics, they may undergo flow-induced vibrations (FIVs), which may result in severe structural fatigue and damage. Here, we present an experimental study on the effect of flexibly hinged splitter plates in the FIV of a flexibly mounted circular cylinder (of diameter D) subject to an uniform cross-flow of velocity u∞. The dynamic response and forcing of the low mass-damping system is characterized for plates of different lengths Lp and different values of the torsional stiffness of the hinge kp. Reductions of the dynamic response of more than 90% can be generally reached at the upper branch, especially when a plate of length l* = Lp/D = 2 with intermediate degree of torsional stiffness is attached, which is shown to represent the best solution as it mitigates the oscillations of the system (cylinder and plate) for the whole range investigated of reduced velocity U* = u∞/fnD = [3:9; 9:8], where fn is the natural frequency of oscillation. In general, the hinged plates are able to attenuate the vortex-induced vibration system response by increasing shedding frequency, until the ratio f* = f/fn > 1 is reached. At high values of U*, a general transition to galloping-like dynamics, characterized by f* < 1, occurs. The tested hinged plates modify the transition between regimes, which is associated with shifts in the phase difference between the forcing and response, combining features of the dynamics of both flexible and static rigid plates already reported in the literature. The use of hinged plates has been proven to provide with a significant attenuation of the system response and its associated drag, a feature that can be considered of practical relevance in many engineering applications. In addition, the key aspects for designing these elements as the torsional stiffness and plate length have been analyzed here.Junta de Andalucía, Universidad de Jaén, and European Funds under Project No. FEDER-UJA 1262764Project Nos. TED2021-131805B-C21 and TED2021-131805B-C22 financed by the Spanish MCIN/AEI/10.13039/501100011033/and the European Union NextGenerationEU/PRTRGrant No. FJC2020-043093-I funded by MCIN/AEI/10.13039/501100011033 and, as appropriate, by “ESF Investing in your future” or by European Union NextGenerationEU/PRTRSpanish MECD through No. FPU20/0726

    Water Stress Enhances the Progression of Branch Dieback and Almond Decline under Field Conditions

    Get PDF
    Branch dieback and tree decline have been described as a common complex disease worldwide in woody crops, with Botryosphaeriaceae and Diaporthaceae being considered the most frequent fungi associated with the disease symptoms. Their behaviour is still uncertain, since they are considered endophytes becoming pathogenic in weakened hosts when stress conditions, such as water deficiency occur. Therefore, the main goal of this study was to determine if water stress enhances general decline on weakened almond trees subjected to different irrigation treatments under natural field conditions. In parallel, the occurrence of fungal species associated with almond decline was also determined in relation to disease progression by fungal isolation, and morphological and molecular based-methods. The symptoms of branch dieback and general decline were observed over time, mainly in the experimental plots subjected to high water deficiency. Botryosphaeriaceae were the most consistently isolated fungi, and Botryosphaeria dothidea was the most frequent. Collophorina hispanica was the second most frequent species and Diaporthe and Cytospora species were isolated in a low frequency. Most of them were recovered from both asymptomatic and symptomatic trees, with their consistency of isolation increasing with the disease severity. This work reveals the need to elucidate the role of biotic and abiotic factors which increase the rate of infection of fungal trunk pathogens, in order to generate important knowledge on their life cycle

    Utility of EST-SNP Markers for Improving Management and Use of Olive Genetic Resources: A Case Study at the Worldwide Olive Germplasm Bank of Córdoba

    Get PDF
    Olive, the emblematic Mediterranean fruit crop, owns a great varietal diversity, which is maintained in ex situ field collections, such as the World Olive Germplasm Bank of Córdoba (WOGBC), Spain. Accurate identification of WOGBC, one of the world’s largest collections, is essential for efficient management and use of olive germplasm. The present study is the first report of the use of a core set of 96 EST-SNP markers for the fingerprinting of 1273 accessions from 29 countries, including both field and new acquired accessions. The EST-SNP fingerprinting made possible the accurate identification of 668 different genotypes, including 148 detected among the new acquired accessions. Despite the overall high genetic diversity found at WOGBC, the EST-SNPs also revealed the presence of remarkable redundant germplasm mostly represented by synonymy cases within and between countries. This finding, together with the presence of homonymy cases, may reflect a continuous interchange of olive cultivars, as well as a common and general approach for their naming. The structure analysis revealed a certain geographic clustering of the analysed germplasm. The EST-SNP panel under study provides a powerful and accurate genotyping tool, allowing for the foundation of a common strategy for efficient safeguarding and management of olive genetic resources.info:eu-repo/semantics/publishedVersio

    Utility of EST-SNP Markers for Improving Management and Use of Olive Genetic Resources: A Case Study at the Worldwide Olive Germplasm Bank of Córdoba

    Get PDF
    Olive, the emblematic Mediterranean fruit crop, owns a great varietal diversity, which is maintained in ex situ field collections, such as the World Olive Germplasm Bank of Córdoba (WOGBC), Spain. Accurate identification of WOGBC, one of the world’s largest collections, is essential for efficient management and use of olive germplasm. The present study is the first report of the use of a core set of 96 EST-SNP markers for the fingerprinting of 1273 accessions from 29 countries, including both field and new acquired accessions. The EST-SNP fingerprinting made possible the accurate identification of 668 different genotypes, including 148 detected among the new acquired accessions. Despite the overall high genetic diversity found at WOGBC, the EST-SNPs also revealed the presence of remarkable redundant germplasm mostly represented by synonymy cases within and between countries. This finding, together with the presence of homonymy cases, may reflect a continuous interchange of olive cultivars, as well as a common and general approach for their naming. The structure analysis revealed a certain geographic clustering of the analysed germplasm. The EST-SNP panel under study provides a powerful and accurate genotyping tool, allowing for the foundation of a common strategy for efficient safeguarding and management of olive genetic resources.EEA San JuanFil: Belaj, Angjelina. Instituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica (IFAPA) . Centro “Alameda del Obispo”; EspañaFil: Ninot, Antònia . IRTA; EspañaFil: Gómez-Gálvez, Francisco J. Instituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica (IFAPA) . Centro “Alameda del Obispo”; EspañaFil: El Riachy, Milad. LARI. Department of Olive and Olive Oil; LíbanoFil: Gurbuz-Veral, Melek. Olive Research Institute. Department of Breeding and Genetics; TurquíaFil: Torres, Myriam Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina.Fil: Torres, Myriam Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lazaj, Adhurim. Qendra e Transferimit te Teknologjise Bujqesore; AlbaniaFil: Klepo, Tatjana.Croatian Agency for Agriculture and Food. Center of Pomology; CroaciaFil: Paz, Sergio. Servicio de Transferencia de Tecnología Conselleria de Agricultura, Desarrollo Rural, Emergencia Climática y Transición Ecológica; EspañaFil: Ugarte, Javier. Gobierno de La Rioja. Servicio de Investigación Agraria y Sanidad Vegetal; EspañaFil: Baldoni, Luciana. National Research Council. Institute of Biosciences and Bioresources; ItaliaFil: Lorite, Ignacio J. Instituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica (IFAPA) . Centro “Alameda del Obispo”; EspañaFil: Šatović, Zlatko .University of Zagreb. Department of Seed Science and Technology, Faculty of Agriculture; CroaciaFil: Šatović, Zlatko. Centre of Excellence for Biodiversity and Molecular Plant Breeding (CoE CroP-BioDiv); CroaciaFil: de la Rosa, Raúl . Instituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica (IFAPA) . Centro “Alameda del Obispo”; Españ

    Usefulness of a New Large Set of High Throughput EST-SNP Markers as a Tool for Olive Germplasm Collection Management

    Get PDF
    Germplasm collections are basic tools for conservation, characterization, and efficient use of olive genetic resources. The identification of the olive cultivars maintained in the collections is an important ongoing task which has been performed by both, morphological and molecular markers. In the present study, based on the sequencing results of previous genomic projects, a new set of 1,043 EST-SNP markers has been identified. In order to evaluate its discrimination capacity and utility in diversity studies, this set of markers was used in a representative number of accessions from 20 different olive growing countries and maintained at the World Olive Germplasm Collection of IFAPA Centre ‘Alameda del Obispo’ (Córdoba, Spain), one of the world’s largest olive germplasm bank. Thus, the cultivated material included: cultivars belonging to previously defined core collections by means of SSR markers and agronomical traits, well known homonymy cases, possible redundancies previously identified in the collection, and recently introduced accessions. Marker stability was tested in repeated analyses of a selected number of accessions, as well as in different trees and accessions belonging to the same cultivar. In addition, 15 genotypes from a cross ‘Picual’ × ‘Arbequina’ cultivars from the IFAPA olive breeding program and a set of 89 wild genotypes were also included in the study. Our results indicate that, despite their relatively wide variability, the new set of EST-SNPs displayed lower levels of genetic diversity than SSRs in the set of olive core collections tested. However, the EST-SNP markers displayed consistent and reliable results from different plant material sources and plant propagation events. The EST-SNPs revealed a clear cut off between inter- and intra-cultivar variation in olive. Besides, they were able to reliably discriminate among different accessions, to detect possible homonymy cases as well as efficiently ascertain the presence of redundant germplasm in the collection. Additionally, these markers were highly transferable to the wild genotypes. These results, together with the low genotyping error rates and the easy and fully automated procedure used to get the genotyping data, validate the new set of EST-SNPs as possible markers of choice for olive cultivar identification

    Genotype, environment and their interaction on olive

    Get PDF
    Resumen del trabajo presentado en la 6th International Conference on the Olive Tree and Olive Products, celebrada en Sevilla (España) del 15 al 19 de octubre de 2018.The wide olive genetic patrimony has revealed high variability for most of the agronomic and oil quality traits of interest in olive growing. Few studies, however, have addressed the interaction of this variability with the environment, a subject of particular interest considering the natural high instability of the Mediterranean climate and the challenge of the predicted climate change. The current work presents results on the interaction between genotype and environment from multi-environment trials of olive cultivars and breeding selections, planted in different edaphoclimatic conditions of Andalusia, Southern Peninsular Spain and Canary Islands. For most of the agronomic and oil quality characters evaluated (flowering phenology, flower quality, pattern of oil accumulation, fatty acid composition and phenol content and composition), significant genotype and environment effects have been observed. For example, olive cultivars grown in Tenerife under much milder winter temperatures than in the Iberian Peninsula showed substantially earlierflowering and oil accumulation. Only in the case of flowering phenology was no significant genotype effect found. Furthermore, a strong genotype x environment effect was highly consistent in all characters considered. Regarding resistance to disease, such as Verticillium wilt, the variability of results from both natural and artificial inoculations also tends to indicate a considerable environmental effect and the need for careful testing of disease evolution. All this information strongly suggests the necessity of comparative trials of olive cultivars for both adequate choice of cultivar and final selection in breeding programs

    Exploring Treated Wastewater Issues Related to Agriculture in Europe, Employing a Quantitative SWOT Analysis

    Get PDF
    AbstractSuWaNu is a research project funded within the EU Commission FP7 framework where one of the objectives is to identify impediments and factors of success for sustainable water treatment and nutrient reuse options. For this purpose several European regional clusters have been framed (in Bulgaria, Germany, Greece, Malta and Spain) while, through a quantitative SWOT analysis, have been identified and quantified the strengths, weaknesses, opportunities and threats of the treated wastewater sector focusing on the economical regional aspects, on research innovation potential and on market exploitation and penetration. The analysis of the contributions of the different clusters included in the SuWaNu project has provided a detailed description of the reclaimed water sector in the European agriculture. After the analysis of more than 200 strengths, opportunities, weaknesses and threats provided by the partners of the project, this study includes a complete description of the use of reclaimed water in the European agriculture. These findings have been used as the fundamental cognition for the development of a joint action plan and several other business plans in the selected regions. A brief discussion on empirical modelling and results, especially regarding the Greek case study, is shown in this paper. A more detailed discussion can be found in the SuWaNu project report, available through the website (http://www.suwanu.eu)

    Applying adaptation response surfaces for managing wheat under perturbed climate and elevated CO2 in a Mediterranean environment

    Get PDF
    This study developed Adaptation Response Surfaces and applied them to a study case in North East Spain on winter crops adaptation, using rainfed winter wheat as reference crop.  Crop responses to perturbed temperature, precipitation and CO2 were simulated by an ensemble of crop models. A set of combined changes on cultivars (on vernalisation requirements and phenology) and management (on sowing date and irrigation) were considered as adaptation options and simulated by the crop model ensemble. The discussion focused on two main issues: 1) the recommended adaptation options for different soil types and perturbation levels, and 2) the need of applying our current knowledge (AOCK) when building a crop model ensemble. The study has been published Agricultural Systems (Available online 25 January 2017, https://doi.org/10.1016/j.agsy.2017.01.009), and the  text below consists on extracts from that paper

    Global maps of soil temperature

    Get PDF
    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world\u27s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications
    corecore