628 research outputs found

    A 3D Printed Power-Split Device for Testing Energy Management Strategies Applied to Hybrid Vehicles

    Get PDF
    This work presents a testbed emulating the hybrid electric vehicles powertrain with both teaching and research purposes. The core of this testbed is a 3D printed epicycloidal gearset actuating as a power split device. Its design and hardware equipment are explained as well as its working principle. From an educational point of view, this system states an interesting control problem and, at the same time, exemplifies the operation of this kind of machines with the scope of a motivating application. Consequently, a teaching methodology comprising this testbed is proposed. In addition, the challenging nature of the system encourage the development of optimization techniques aimed at reducing the overall system energy consumption. Results of a preliminary experiment are satisfactory addressed. As a consequence, the presented testbed is proposed as a remote lab for teaching and benchmarking new control strategies

    Aportació al coneixement florístic de l’Espai Natural de les Guilleries-Savassona.

    Get PDF
    En aquesta memòria donem compte de la flora de l’Espai Natural de les Guilleries-Savassona. El projecte que empara aquesta tasca s’anomena “Contribució al coneixement florístic de la porció occidental i elaboració d’un catàleg florístic crític de l’Espai Natural de les Guilleries-Savassona.”. La informació aquí inclosa és una aproximació molt avançada al coneixement florístic d’aquest divers territori, de tal manera que creiem que es pot considerar com una primera versió de la flora de l’Espai Natural.Una part d’aquesta recerca ha estat recolzada per l’Agència de Gestió d'Ajuts Universitaris i de Recerca (ACOM-DGR; Generalitat de Catalunya) i per l’Espai Natural de Guilleries-Savassona (Diputació de Barcelona)

    Catàleg florístic del DG54 (Guilleries – Collsacabra). Primera versió.

    Get PDF
    Aquest treball és una contribució significativa a l catàleg florístic de les valls de Sau i de Susqueda (Guilleries i Collsacabra). Més concretament, aportem una llista que inclou tots els tàxons observats pels autors a la quadrícula UTM DG54 (de 100 km2), tan espontanis com subespontanis o naturalitzats. Aportem una sola localitat per a cada tàxon i en donem la coordenada amb precisió d'un quilòmetre (en projecció ED50).Una part d’aquesta recerca ha estat recolzada per l’Agència de Gestió d'Ajuts Universitaris i de Recerca (ACOM-DGR; Generalitat de Catalunya) i per l’Espai Natural de Guilleries-Savassona (Diputació de Barcelona)

    Effect of patch size on seed removal by harvester ants

    Get PDF
    The harvester ant Messor barbarus can be responsible for high weed seed losses in dry land cereals in Spain. Because weeds occur in patches, harvester ants have to be able to find and exploit patches. However, seed patches can differ in size and may, therefore, differ in the probability of being discovered and exploited. Here, 90 patches varying in size from 0.25 to 9 m2 were created in three 50 × 50 m subareas in a cereal field. Oat seeds were sown as weed seed surrogates in the patches at 2000 seeds m−2. After 24 h, those remaining were collected and the exploitation rate (the percentage of seeds removed per patch discovered by ants) was estimated. Harvester ant nests and the location of the seed patches were georeferenced and used to estimate distances between them. The patch encounter rate (the proportion of patches discovered by the ants) decreased slightly, but significantly, with decreasing patch size, though not the exploitation rate, which was lowest in the smallest patches (78-94%) and highest in the largest (99-100%). Seed patches that were not found or partially exploited were mostly located in subareas with a lower ant nest density or a longer distance away from the nearest nest than seed patches that were fully exploited. The results of this study indicate that the interaction between the spatial distribution of ant nests and the patchy distribution of seeds can create opportunities for seeds to be subjected to lower levels of predation

    Efecto del laboreo mínimo (chisel), la fertilización y los abonos verdes sobre la flora arvense y los rendimientos en una rotación de cultivos de cereales y leguminosas ecológicos

    Get PDF
    Effects of reduced tillage, fertilization and green manures on the weeds and crop yields in a cereal-legume crop rotation under organic farming. On 2011, we established a long-term experiment to evaluate the effects of reduced tillage (chisel vs mouldboard plough), fertilization with semicomposted manure and sowing of green manures before spring crops, on the crop yields and weed abundance in a 5-year rotation (spelt, chickpea, wheat, lentil and spelt). After five years, there was not noticeable increment in weed abundance or richness. Reduced tillage caused a significant increase of weeds compared with mouldboard plough, but it this increase did not cause significant yield loss in cereal crops compared with mouldboard plough. Green manures exerted a strong weed suppression, although this effect did not persist on the subsequent (legume) crop. Entre 2011 y 2016 se realizó un experimento para evaluar el efecto del laboreo mínimo (chisel) respecto a arado de vertedera, de la fertilización con estiércol y de la siembra de abonos verdes antes de los cultivos de primavera, sobre los rendimientos del cultivo y la abundancia de las malas hierbas, en una rotación de 5 años (espelta, garbanzo, trigo, lenteja y espelta). El laboreo mínimo provocó un aumento significativo de las arvenses pero sin conllevar pérdidas significativas en los rendimientos de los cereales respecto a los rendimientos con el arado de vertedera. El abono verde ejerció un fuerte control sobre las malas hierbas, aunque este efecto no persistió durante el cultivo de la leguminosa inmediatamente posterior

    EFFECT OF CONSERVATION PRACTICES ON FUNCTIONAL DIVERSITY AND ASSEMBLY OF WEED COMMUNITIES: A DATABASE OF FUNCTIONAL TRAITS

    Get PDF
    The incorporation of conservation agriculture techniques (e.g. reduced tillage and green manures) in organic farming systems brings many benefits to the environment and reduces energy use (Holland, 2004). One of the main drawbacks of the use of reduced tillage is the potential increase in weed infestation and shifts in the weed community composition, sometimes to the benefit of more difficult-to-control species (Bàrberi, 2002; Peigné et al., 2007; Sans et al., 2011). However, weeds have an important role in maintaining farmland functional biodiversity (Bàrberi et al, 2010; Caballero et al., 2010), and this should be balanced with their potential negative impact on crop yield and quality. Within the frame of the European project “Reduced tillage and green manures for sustainable cropping systems” (TILMAN-ORG), in 2012 we started a study with the aim of evaluating the effects of conservation agricultural methods on functional attributes of weed communities, taking into account both the potential detrimental effects of weeds on crop growth and yield and the potential ecological services or dis-services. Knowledge on the outcome of positive and negative effects will be useful in the context of evaluating soil conservation practices in organic farming. In this paper we highlight the approach used to build the weed functional traits database, the first step in this study

    Crop yield, weed infestation and soil fertility responses to contrasted ploughing intensity and manure additions in a Mediterranean organic crop rotation

    Get PDF
    Conservation agriculture and organic farming are two alternative strategies that aim to improve soil quality and fertility in arable cropping systems through the deployment of different practices, that are rarely combined. While conservation agriculture practices include reducing tillage intensity and maintaining soil cover all year round to prevent soil erosion, organic farming focuses on nutrient recycling, using farmyard manure and green manure to enhance soil quality. However, these practices are not free from side-effects, such as increasing weed infestation or limited nutrient availability. Therefore it is necessary to explore the sustainability of their combination under local environmental constraints. The objectives of this study were to evaluate the effects of tillage type (mouldboard vs. chisel ploughing), fertilization and green manure on soil parameters (SOC, N, bulk density, carbon stocks, and soil microbial biomass Cmic and Nmic), weed abundance and crop yields in a four-year rotation of spelt, chickpea, winter wheat and lentil in the Mediterranean region (Catalonia, Spain). Tillage and green manure did not affect crop yields or weed biomass, although during the last year of the experiment, plots with mouldboard ploughing had less weed biomass and higher lentil biomass. Fertilization was the most important factor, increasing the cereal yields, SOC, N and soil microbial biomass (Cmic and Nmic) content of the soil. However, fertilization did not favour chickpea and lentil crops because weed competition limited legume crop growth. Overall, there was a loss of SOC and a reduction of carbon stocks over the four years of the trial in the soil because of the deep soil tillage (25 cm) and low crop productivity irrespective of tillage type. In contrast, N content increased in all of the plots and was enhanced by fertilization. The use of chisel plough stratified the distribution of SOC and N in the surface layers (0-10 cm). Both Cmic and Cmic/SOC ratio increased in fertilized treatments, suggesting an increased lability of SOC. The application of more stabilized organic matter may be a better practice to build up soil organic matter and to maintain crop yields in organic farming systems

    Architecture for Text Sign Localization and Recognition

    Get PDF
    This paper describes a low complexity strategy for detecting and recognizing text signs automatically. Traditional approaches use large image algorithms for detecting the text sign, followed by the application of an Optical Character Recognition (OCR) algorithm in the previously identified areas. This paper proposes a new architecture that applies the OCR to a whole lightly treated image and then carries out the text detection process of the OCR output. The strategy presented in this paper significantly reduces the processing time required for text localization in an image, while guaranteeing a high recognition rate. This strategy will facilitate the incorporation of video processing-based applications into the automatic detection of text sign similar to that of a smartphone. These applications will increase the autonomy of visually impaired people in their daily life

    Laguna Seca sediments reveal environmental and climate change during the latest Pleistocene and Holocene in Sierra Nevada, southern Iberian Peninsula

    Get PDF
    This study was supported by the I + D + i projects CGL2013-47038- R, CGL2017-85415-R, PID2019-1049449GB-I00, and PID2021- 125619OB-C21/C22 funded by Ministerio Ciencia e Innovación/Agencia Estatal de Investigación/ 10.13039/501100011033/ and Fondo Europeo de Desarrollo Regional “Una manera de hacer Europa”, I + D + i projects A-RNM-336-UGR20 and P20_00059 of the action “Proyectos I + D + i del Programa Operativo FEDER - Junta de Andalucía - UGR” and the research group RNM-190. This research is part of the project “Thematic Center on Mountain Ecosystem & Remote sensing, Deep learning- AI e-Services University of Granada-Sierra Nevada” (LifeWatch-2019- 10-UGR-01), which has been co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program 2014-2020 (POPE), LifeWatch-ERIC action line. José Carrión was supported by the I + D + I project PID2019-1049449 GB-I00 funded by MCIN/AEI/ 10.13039/501100011033/ and FEDER “Una manera de hacer Europa” and the fellowship 20788/PI/18 of Fundación Séneca. We thank Javier Jaimez for his help with the core drilling in Laguna Seca and Alejandro Navarro and Aurora Baquera for the sediment sampling. ALA acknowledges the predoctoral fellowship BES- 2018-084293 provide by the MCIN/ AEI/ 10.13039/5011000110 33/. CLB acknowledges the European Union for her Marie Sklodowska-Curie grant agreement number 892487 under Horizon 2020 funds. JC acknowledges the Ministerio de Ciencia e Innovación of the Spanish Government for the grant number FJC2020-044215-I of the Juan de la Cierva Formación postdoctoral program.Sedimentation in most glacial lakes and wetlands in the Sierra Nevada (southern Iberian Peninsula) began after the last deglaciation and since the Younger Dryas (YD)-Early Holocene (EH) transition. Therefore, until now, studies on older sedimentary records were lacking in this alpine area, which limits the paleoenvironmental and paleoclimatic information to the Holocene. In this study, we studied palynomorphs from the alpine record from Laguna Seca (LS), the longest and oldest (∼18,000 cal yr BP = 18 kyr) sedimentary record in the Sierra Nevada to investigate the response of forests and lake environments in the western Mediterranean area to climate changes and human impact during the latest Pleistocene and Holocene. The deepest lake conditions occurred during the last deglaciation, indicated by the occurrence of Pediastrum algae, which showed highest abundances during the Heinrich Stadial 1 (HS1) and Bølling-Allerød (B-A) transition. Xerophyte herbs such as Artemisia, Ephedra, and Amaranthaceae were highest during the late B-A and YD indicating regional aridity. Poaceae (grasses) were maxima in the B-A and EH, probably indicating expansion in the barren areas after deglaciation. Maximum in temperature and humidity during the EH and cooling and aridification in the Middle (MH) and Late Holocene (LH) are indicated by the changes in the abundance of deciduous Quercus and Pinus forest species. Botryococcus algae increased during the Early Holocene, while the rest of the algae almost vanished, which could indicate that the lake became very productive but shallower until 8.2 kyr. The lake level lowered and became seasonal in the Middle-Late Holocene transition, coinciding with the regional climate aridification. Microcharcoal analysis done on the palynological preparations agrees with the vegetation changes, showing maxima in the EH and MH, related with the maximum in regional forest occurrence, and a decrease in the LH when the Mediterranean vegetation, and thus fuel availability, diminished. This record shows evidence of anthropogenic impact in the last centuries by cultivation, reforestation, cattle grazing, enhanced erosion and eutrophication.I + D + i projects CGL2013-47038- R, CGL2017-85415-R, PID2019-1049449GB-I00, and PID2021- 125619OB-C21/C22 funded by Ministerio Ciencia e Innovación/Agencia Estatal de Investigación/ 10.13039/501100011033/ and Fondo Europeo de Desarrollo Regional “Una manera de hacer Europa”I + D + i projects A-RNM-336-UGR20 and P20_00059 of the action “Proyectos I + D + i del Programa Operativo FEDER - Junta de Andalucía - UGR” and the research group RNM-190Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program 2014-2020 (POPE), LifeWatch-ERIC action lineI + D + I project PID2019-1049449 GB-I00 funded by MCIN/AEI/ 10.13039/501100011033/ and FEDER “Una manera de hacer Europa” and the fellowship 20788/PI/18 of Fundación SénecaPredoctoral fellowship BES- 2018-084293 provide by the MCIN/ AEI/ 10.13039/5011000110 33/European Union for her Marie Sklodowska-Curie grant agreement number 892487 under Horizon 2020 fundsMinisterio de Ciencia e Innovación of the Spanish Government for the grant number FJC2020-044215-I of the Juan de la Cierva Formación postdoctoral progra

    Systematics and phylogeography of the Mediterranean Helichysum pendulum complex (Compositae) inferred from nuclear and chloroplast DNA and morphometrics analyses

    Get PDF
    Multiple factors related to complex geomorphological and climatic history, in addition to biological factors such as hybridization, hinder the definition of some Mediterranean plant groups. The existence of controversial taxonomic treatments, the possible hybridization events involved, and its unknown evolutionary history, make the Helichrysum pendulum complex of H. sect. Stoechadina an ideal model to understand general processes of Mediterranean plant systematics and evolution. The mosaic range of the complex, which is distributed over several islands and continental areas in the western-central Mediterranean Basin, provides an opportunity to investigate how past connections and disconnections between landmasses may have determined the current geographic distribution of genetic variation in this area. The cpDNA region rpl32-trnL intergenic spacer and the nrDNA region ETS were sequenced for 1-8 individuals from each of the 44 populations sampled, covering all taxa and the whole geographic range of the complex. These individuals were analysed together with a broad sampling of the remaining members of sect. Stoechadina. In addition, detailed multivariate analyses of morphological characters were performed for the whole section and for the H. pendulum complex. Considering together distinctive genetic and morphological traits, our species concept is presented and discussed in a context of integrative taxonomy, and five species are recognized within the complex: H. errerae, H. melitense, H. pendulum, H. saxatile and H. valentinum. The first three species are recognizable by qualitative and quantitative morphological traits, and are genetically distinguishable from the rest as shown by the molecular markers analysed. The two last species are reported here to have a putative ancient hybrid origin and are also genetically distinguishable from the rest but morphologically recognisable only by quantitative characters. Phylogenetic relationships shown by nuclear and chloroplast markers, and an intermediate morphology between the two putative parental taxa, point to H. pendulum and H. italicum as the putative parental taxa for H. saxatile, and H. pendulum and H. stoechas as putative parental taxa for H. valentinum. In a discriminant analysis of the five species, 97.8% of all individuals were classified correctly. The high level of haplotype and ribotype diversity observed in North Africa indicates that this region is either the area of origin of the complex or a secondary contact zone. Our results suggest that the complex colonized several islands and migrated through the Gibraltar and Sicilian Straits during phases of low sea level, favoured by local dispersal events that promoted its gradual range expansion. The occurrence of the complex in the Balearic Islands, which have remained isolated even during low sea level phases, could be explained by stochastic long-distance dispersal events
    corecore