139 research outputs found

    Vertical geotechnical engineering techniques applied to the rehabilitation of Pleistocene sites

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    La aplicación de una serie de técnicas propias de la geotecnia vertical y de la consolidación de taludes y laderas inestables se presenta por primera vez aplicada a la rehabilitación de yacimientos pleistocenos ubicados en antiguas canteras. Un conjunto de actuaciones especializadas permite garantizar la seguridad en los trabajos así como la preservación de la integridad de los yacimientos ubicados en cortes verticales y laderas rocosas. La rehabilitación realizada en el yacimiento de la Cova del Rinoceront (macizo del Garraf, NE de España), ubicado en el frente de explotación de una antigua cantera de piedra caliza, es el primer ejemplo conocido en la Península Ibérica donde la geotecnia vertical ha sido utilizada en este tipo de contextos y, por lo tanto, los resultados pueden ser utilizados como un posible modelo de futuro para próximas intervenciones.La aplicación de una serie de técnicas propias de la geotecnia vertical y de la consolidación de taludes y laderas inestables se presenta por primera vez aplicada a la rehabilitación de yacimientos pleistocenos ubicados en antiguas canteras. Un conjunto de actuaciones especializadas permite garantizar la seguridad en los trabajos así como la preservación de la integridad de los yacimientos ubicados en cortes verticales y laderas rocosas. La rehabilitación realizada en el yacimiento de la Cova del Rinoceront (macizo del Garraf, NE de España), ubicado en el frente de explotación de una antigua cantera de piedra caliza, es el primer ejemplo conocido en la Península Ibérica donde la geotecnia vertical ha sido utilizada en este tipo de contextos y, por lo tanto, los resultados pueden ser utilizados como un posible modelo de futuro para próximas intervenciones.Over the last two decades of the nineteenth century and part of the twentieth century, many Pleistocene sites in the Iberian Peninsula have been discovered through quarrying, mining and railways construction, amongst other industrial activities. This paper describes a new methodology for rehabilitating Pleistocene sites, based on the application of geotechnical engineering and unstable slope treatment. These techniques guarantee site preservation and fieldwork safety conditions for sites inside quarries or on slopes. The repair work carried out in Cova del Rinoceront (Garraf massif, NE Spain) is the first example of the geotechnical restoration process in action in archaeological sites in the Iberian Peninsula. Furthermore, the Cova del Rinoceront rehabilitation serves as a model for other similar Pleistocene sites

    Analysis of the uncertainty in the monetary valuation of ecosystem services - a case study at the river basin scale

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    Ecosystem services provide multiple benefits to human wellbeing and are increasingly considered by 18 policy-makers in environmental management. However, the uncertainty related with the monetary 19 valuation of these benefits is not yet adequately defined or integrated by policy-makers. Given this 20 background, our aim was to quantify different sources of uncertainty when performing monetary 21 valuation of ecosystem services, in order to provide a series of guidelines to reduce them. With an 22 example of 4 ecosystem services (i.e., water provisioning, waste treatment, erosion protection, and 23 habitat for species) provided at the river basin scale, we quantified the uncertainty associated with 24 the following sources: (1) the number of services considered, (2) the number of benefits considered 25 for each service, (3) the valuation metrics (i.e. valuation methods) used to value benefits, and (4) the 26 uncertainty of the parameters included in the valuation metrics. Results indicate that the highest 27 uncertainty was caused by the number of services considered, as well as by the number of benefits 28 considered for each service, whereas the parametric uncertainty was similar to the one related to the 29 selection of valuation metric, thus suggesting that the parametric uncertainty, which is the only 30 uncertainty type commonly considered, was less critical than the structural uncertainty, which is in 31 turn mainly dependent on the decision-making context. Given the uncertainty associated to the 32 valuation structure, special attention should be given to the selection of services, benefits and 33 metrics according to a given context

    Autonomous underwater vehicle

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    Autonomous Underwater Vehicles (AUVs) have many applications ranging from submerged pipeline inspection and maintenance to mapping and clearing mine fields. The purpose of this project is to design and construct an AUV capable of navigating in 3 dimensions, and perform elementary autonomous tasks such as obstacle detection and avoidance. The AUV would operate in shallow water (depths of 20 ft or less). It would be suited to applications such as ship hull inspection, bridge inspection, mapping, and photography in shallow waters. This project will provide a platform for future development of AUVs at Drexel, namely the gradual addition of better sensing and navigating capabilities. The complete design for this robot requires construction and integration of several mechanical and electrical sub-systems. A propeller driven mode of locomotion coupled with a ballast system will allow the robot to navigate in 3 dimensions and fix its position (i.e., “hover” in one spot). A communication scheme will be implemented to operate the vessel to depths of 20 ft with an operational radius of 15 ft. A sensor suite comprised of accelerometers, a compass, and transducers will estimate the robot’s orientation and detect obstacles in its path. The robot will require regulated and properly protected power supply and electronics systems. All individual components and subsystems will be tested on land. Following integration, the completed system will be tested in water, with the objective of demonstrating navigational and obstacle detection capabilities. This process will be directed at discovering design tradeoffs and areas where future research and development are needed

    Co-production pathway of an end-to-end climate service for improved decision-making in the wine sector

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    Climate services are one of the tools that can support the agriculture sector to address the impacts of climate change on agricultural production systems, not only considering climatic aspects but also social needs. This work describes the knowledge co-production journey of the EU-funded project MED-GOLD to create an end-to-end climate service for wine sector users. In this work, co-production is understood as an iterative, interactive and collaborative process among an interdisciplinary group of scientists and users that were engaged, involved, and empowered. The co-production process included activities to raise awareness on the vulnerability of grape and wine production to climate change, exchange knowledge between climate service providers and users, and co-develop customised climate services, such as the MED-GOLD Dashboard. Lessons learned are that repeated interaction between scientists and users allow to better frame research questions, jointly decide how to address these questions, and test the outcomes with feedback from real-world decision-makers. Furthermore, having a user who co-developed the service and helped assess its added value was key to ensure that it could truly inform decision-making needs and to promote its broader uptake by the wine sector community. Although the MED-GOLD Dashboard constitutes the most tangible result of this collaboration, the outcomes of co-production also encompass the joint learning process, the shared sense of ownership, and the co-creation of new knowledge between scientists and stakeholders. Nevertheless, further research will be needed to understand how the knowledge coproduced with a single user can be scaled up to users with other profiles and requirements

    Climateurope festival: an innovative way of linking science and society

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    The Climateurope Festivals were designed to create synergies between different European, national and international initiatives in the fields of Earth-system modelling & Climate Services and enhance the transfer of information between suppliers and users. It gave an opportunity to display best in class outcomes and engage in world class networking in a less rigid environment than a scientific conference. A number of formats were adopted in the Festival, from traditional impulse talks to innovative interactive sessions, and the thought-provoking discussions allowed the participants to share their experiences and knowledge around the advantages and challenges that Climate Services face within different sectors. Three Climateurope Festivals were originally planned to be held across Europe. Two Festivals were successfully organised, the first in Valencia in 2017, and the second in Belgrade in 2018. Due to the COVID-19 pandemic and associated lockdowns and travel restrictions, the third and final Festival was held online as a series of virtual web-based Festivals in 2020/2021. The Festivals were highly valued by participants. There was a strong desire by the Climateurope network to continue a science-stakeholder dialogue and make the Climateurope Festivals a regular event

    Variability in ecosystem service measurement: A pollination service case study

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    Research quantifying ecosystem services (ES) - collectively, the benefits that society obtains from ecosystems - is rapidly increasing. Despite the seemingly straightforward definition, a wide variety of methods are used to measure ES. This methodological variability has largely been ignored, and standard protocols to select measures that capture ES provision have yet to be established. Furthermore, most published papers do not include explicit definitions of individual ES. We surveyed the literature on pollination ES to assess the range of measurement approaches, focusing on three essential steps: (1) definition of the ES, (2) identification of components contributing to ES delivery, and (3) selection of metrics to represent these components. We found considerable variation in how pollination as an ES - a relatively well-defined service - is measured. We discuss potential causes of this variability and provide suggestions to address this issue. Consistency in ES measurement, or a clear explanation of selected definitions and metrics, is critical to facilitate comparisons among studies and inform ecosystem management

    Autotrophic and heterotrophic acquisition of carbon and nitrogen by a mixotrophic chrysophyte established through stable isotope analysis

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    Collectively, phagotrophic algae (mixotrophs) form a functional continuum of nutritional modes between autotrophy and heterotrophy, but the specific physiological benefits of mixotrophic nutrition differ among taxa. Ochromonas spp. are ubiquitous chrysophytes that exhibit high nutritional flexibility, although most species generally fall towards the heterotrophic end of the mixotrophy spectrum. We assessed the sources of carbon and nitrogen in Ochromonas sp. strain BG-1 growing mixotrophically via short-term stable isotope probing. An axenic culture was grown in the presence of either heat-killed bacteria enriched with ^(15)N and ^(13)C, or unlabeled heat-killed bacteria and labeled inorganic substrates (^(13)C-bicarbonate and ^(15)N-ammonium). The alga exhibited high growth rates (up to 2 divisions per day) only until heat-killed bacteria were depleted. NanoSIMS and bulk IRMS isotope analyses revealed that Ochromonas obtained 84–99% of its carbon and 88–95% of its nitrogen from consumed bacteria. The chrysophyte assimilated inorganic ^(13)C-carbon and ^(15)N-nitrogen when bacterial abundances were very low, but autotrophic (photosynthetic) activity was insufficient to support net population growth of the alga. Our use of nanoSIMS represents its first application towards the study of a mixotrophic alga, enabling a better understanding and quantitative assessment of carbon and nutrient acquisition by this species

    Monitoring climate related risk and opportunities for the wine sector: The MED-GOLD pilot service

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    MED-GOLD was a 54-months research and innovation project, whose main aim was to co-develop climate services for three staples of the Mediterranean food system, namely grapes, olives and durum wheat. This paper describes the methodology adopted for the co-development of the pilot climate service for the wine sector, focusing on the Douro Wine Region in northern Portugal. In the first step, the MED-GOLD industrial partner SOGRAPE identified key decisions and users’ needs for the wine sector in the Douro region by involving managers from their own vineyards in that region. From this information, the relevant bioclimatic indicators (and associated essential climate variables) were selected. Afterwards, two compound risk indices, the Sanitary and Heat Risk indices, were introduced as a combination of some of the aforementioned bioclimatic indicators. This methodological work was validated against the empirical climate characterization for the region of interest, of several ‘bad’ and ‘good’ years chosen by users according to their recollections of grape and wine production outcomes, namely quality and yields. In this paper, the overall strategy for selection of these years is presented. The components of the service based on historical climate, seasonal predictions and longer-term climate projections are described along with the visual interface developed: the MED-GOLD Dashboard, an interactive tool that displays detailed historical climate data, seasonal predictions and climate projections. The Dashboard consists of an ICT platform with a map-based user-focused front end to aid easy access to and manipulation of the data. The Dashboard was iteratively co-designed with the users to ensure their needs were met

    Carbon nanotube networks as gas sensors for NO2 detection

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    Networks of different carbon nanotube (CNT) materials were investigated as resistive gas sensors for NO2 detection. Sensor films were fabricated by airbrushing dispersions of double-walled and multi-walled CNTs (DWNTs and MWNTs, respectively) on alumina substrates. Sensors were characterized by resistance measurements from 25 to 250 °C in air atmosphere in order to find the optimum detection temperature. Our results indicate that CNT networks were sensitive to NO2 concentrations as low as 0.1 ppm. All tested sensors provided significantly lower response to interfering gases such as H2, NH3, toluene and octane. We demonstrate that the measured sensitivity upon exposure to NO2 strongly depends on the employed CNT material. The highest sensitivity values were obtained at temperatures ranging between 100 and 200 °C. The best sensor performance, in terms of recovery time, was however achieved at 250 °C. Issues related to the gas detection mechanisms, as well as to CNT network thermal stability in detection experiments performed in air at high operation temperatures are also discussed.This work has been supported by MEC (Spain, projects TEC2004-05098-C02-01/MIC and TEC2004-05098-C02-02/MIC, Programa I3 2006 8 0I 060) and the European Regional Development Fund (ERDF).Peer reviewe
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