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15 Research products, page 1 of 2

  • Publications
  • 2013-2022
  • 0202 electrical engineering
  • ES
  • Flore (Florence Research Repository)

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  • Publication . Part of book or chapter of book . Conference object . 2014
    Open Access
    Authors: 
    Duccio Troiano; Andrés García Morro; Alessandro Merlo; Eduardo Vendrell Vidal;
    Publisher: Springer International Publishing
    Country: Italy

    Despite extensive research having been conducted on the subject, the problem of three-dimensional information systems for historical cities is actually still unresolved. In addition, commercially available software seems to be increasingly aiming at a quick development of unspecific urban settings, rather than at a metrically and perceptively faithful representation of reality. In this scenario, the SIUR 3D software (Sistema Informativo URbano tridimensionale) is based on a management structure that links an interactive, photorealistic and metrically reliable model of a city with a qualitative database of the historical, archaeological and material scope of an architectural part. Such application uses the Unity 3D game engine for geometrical models management and is equipped for online data sharing.

  • Open Access English
    Authors: 
    Minghao Wu; Vasiliki Stratigaki; Peter Troch; Corrado Altomare; Tim Verbrugghe; Alejandro J. C. Crespo; Lorenzo Cappietti; Matthew Hall; Moncho Gómez-Gesteira;
    Publisher: MDPI AG
    Countries: Italy, Belgium
    Project: EC | MARINET2 (731084)

    This paper describes experimental research on a floating moored Oscillating Water Column (OWC)-type Wave-Energy Converter (WEC) carried out in the wave flume of the Coastal Engineering Research Group of Ghent University. This research has been introduced to cover the existing data scarcity and knowledge gaps regarding response of moored floating OWC WECs. The obtained data will be available in the future for the validation of nonlinear numerical models. The experiment focuses on the assessment of the nonlinear motion and mooring-line response of a 1:25 floating moored OWC WEC model to regular waves. The OWC WEC model motion has 6 degrees of freedom and is limited by a symmetrical 4-point mooring system. The model is composed of a chamber with an orifice on top of it to simulate the power-take-off (PTO) system and the associated damping of the motion of the OWC WEC model. In the first place, the motion response in waves of the moored floating OWC WEC model is investigated and the water surface elevation in the OWC WEC chamber is measured. Secondly, two different mooring-line materials (iron chains and nylon ropes) are tested and the corresponding OWC WEC model motions and mooring-line tensions are measured. The performance of these two materials is similar in small-amplitude waves but different in large wave-amplitude conditions. Thirdly, the influence of different PTO conditions is investigated by varying the diameter of the top orifice of the OWC WEC model. The results show that the PTO damping does not affect the OWC WEC motion but has an impact on the water surface elevation inside the OWC chamber. In addition, an unbalanced mooring configuration is discussed. Finally, the obtained data for a moored cubic model in waves are presented, which is a benchmarking case for future validation purposes.

  • Open Access English
    Authors: 
    Marcantonio Catelani; Lorenzo Ciani; Diego Galar; Gabriele Patrizi;
    Publisher: Institute of Electrical and Electronics Engineers Inc.
    Countries: Spain, Italy

    A wind turbine is a complex system used to convert the kinetic energy of the wind into electrical energy. During the turbine design phase, a risk assessment is mandatory to reduce the machine downtime and the Operation & Maintenance cost and to ensure service continuity. This paper proposes a procedure based on Failure Modes, Effects, and Criticality Analysis to take into account every possible criticality that could lead to a turbine shutdown. Currently, a standard procedure to be applied for evaluation of the risk priority number threshold is still not available. Trying to fill this need, this paper proposes a new approach for the Risk Priority Number (RPN) prioritization based on a statistical analysis and compares the proposed method with the only three quantitative prioritization techniques found in literature. The proposed procedure was applied to the electrical and electronic components included in a Spanish 2 MW on-shore wind turbine.

  • Open Access
    Authors: 
    Asier González-González; Alberto Jimenez Cortadi; Diego Galar; Lorenzo Ciani;
    Publisher: Elsevier BV
    Countries: Italy, Spain

    Abstract With the increase of wind power capacity worldwide, researchers are focusing their attention on the operation and maintenance of wind turbines. A proper pitch controller must be designed to extend the life cycle of a wind turbine’s blades and tower. The pitch control system has two primaries, but conflicting, objectives: to maximize the wind energy captured and converted into electrical energy and to minimize fatigue and mechanical load. Four metrics have been proposed to balance these two objectives. Also, diverse pitch controller strategies are proposed in this paper to evaluate these objectives. This paper proposes a novel metrics approach to achieve the conflicting objectives with a maintenance focus. It uses a 100 kW wind turbine as a case study to simulate the proposed pitch control strategies and evaluate with the metrics proposed. The results are shown in two tables due to two different wind models are used.

  • Open Access
    Authors: 
    Pablo Gonzalez-de-Santos; Angela Ribeiro; César Fernández-Quintanilla; Francisca López-Granados; Michael Brandstoetter; Slobodanka Tomic; Stefania Pedrazzi; Andrea Peruzzi; Gonzalo Pajares; George Kaplanis; +6 more
    Publisher: Springer Science and Business Media LLC
    Countries: Italy, Spain, France, Spain, Spain, Spain, Italy
    Project: EC | RHEA (245986), EC | RHEA (245986)

    Feeding the growing global population requires an annual increase in food production. This requirement suggests an increase in the use of pesticides, which represents an unsustainable chemical load for the environment. To reduce pesticide input and preserve the environment while maintaining the necessary level of food production, the efficiency of relevant processes must be drastically improved. Within this context, this research strived to design, develop, test and assess a new generation of automatic and robotic systems for effective weed and pest control aimed at diminishing the use of agricultural chemical inputs, increasing crop quality and improving the health and safety of production operators. To achieve this overall objective, a fleet of heterogeneous ground and aerial robots was developed and equipped with innovative sensors, enhanced end-effectors and improved decision control algorithms to cover a large variety of agricultural situations. This article describes the scientific and technical objectives, challenges and outcomes achieved in three common crops. The research leading to these results received funding from the European Union’s Seventh Framework Programme [FP7/2007-2013] under Grant Agreement nº 245986. Support for publishing this article has been provided by CSIC. González-de-Santos, Pablo et al. Peer reviewed

  • Open Access
    Authors: 
    Mohammad Saffari; Cristina Piselli; Alvaro de Gracia; Anna Laura Pisello; Franco Cotana; Luisa F. Cabeza;
    Publisher: Elsevier
    Countries: Spain, Spain, Spain, Italy, Spain
    Project: EC | INPATH-TES (657466), EC | INNOSTORAGE (610692), EC | INPATH-TES (657466), EC | INNOSTORAGE (610692)

    A considerable amount of energy is used in the building sector for air conditioning purposes. Additionally, the building sector contributes to the urban heat island (UHI) phenomenon which causes temperature rise in urban areas. Cool roof is an emerging passive cooling technology that can contribute to reduce the cooling energy use in buildings and to mitigate the UHI effects in the urban area. Cool roofs and reflective coatings, despite of being effective in terms of reducing the cooling thermal loads in buildings and decrease the UHI, can suffer from extreme thermal stress which negatively influences their lifespan and performance. Thermal energy storage (TES) is a promising technology which can be applied together with cool roof technology to decrease the extreme thermal stress due to solar radiation as well as providing thermal inertia to the building. In this study, simulation-based optimization will be used to optimize the PCM melting temperature when integrated into a polyurethane-based cool roof membrane to reduce the thermal stress of the cool roof and also to improve the annual energy performance of the building. The optimization results showed that the application of PCM and cool roof technologies together can reduce the severe thermal stress of the cool roof membrane when the optimization objective is the annual thermal stress of the cool roof. On the other hand, when PCM melting temperature is optimized to reduce the annual energy needs, higher annual energy savings could be achieved with acceptable reductions in the cool roof membrane thermal stress. The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES). The work is partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER) and ENE2015-64117-C5-3-R (MINECO/FEDER)). The authors would like to thank the Catalan Government for the quality accreditation given to their research group GREA (2014 SGR 123). GREA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. This project has received funding from the European Commission Seventh Framework Program (FP/2007-2013) under Grant agreement Nº PIRSES-GA-2013-610692 (INNOSTORAGE). Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-19940. A.L. Pisello’s acknowledgments are due to the UNESCO Chair “Water Resources Management and Culture”, for supporting her research.

  • Open Access English
    Authors: 
    Grazia Tucci; E. I. Parisi; Valentina Bonora; Lidia Fiorini; Alessandro Conti; M. Corongiu; Juan Ortiz-Sanz; Mariluz Gil-Docampo; T. Rego-Sanmartín; Marcos Arza-García;
    Publisher: Copernicus Publications
    Country: Italy

    Abstract. The democratization and accessibility of low-cost devices for image acquisition and the development of highly automated procedures for orientation and dense image matching allow almost every person to be a potential producer of photogrammetric models. The diffusion of image-based technologies to produce 3D models amongst wider audiences entails however some risks, as the lack of critical awareness of the final quality of the outputs. Information and education about potentialities and limitations of reality-based digitization by photogrammetry may help spreading procedures and methods for the correct use of this technology. This paper presents the results of one of the funded projects within the 2018 ISPRS Capacity Building Initiatives “Education and training resources on digital photogrammetry”. The production of multimedia material for supporting smart educational teaching and learning approaches will be reported, as well as experiences on their application on case studies. Blended innovative teaching and learning pedagogical approaches have been tested, as Flipped Classroom (FC), Learning-by-doing (LBD), Collaborative Learning (CL), and Challenge-Based Learning (CBL), supported by multimedia tools for capacity-building and knowledge transfer. The implementation of multimedia materials for supporting teaching strategies resulted in the production of updated and engaging resources, as videos, tutorials, and datasets to be used during courses, workshops, and seminars targeted to different user groups. The combination of teaching strategies and multimedia supporting materials were tested within national and international projects, from academic courses to complete non-experts, from activities on the field to online and distance learning.

  • Open Access English
    Authors: 
    Cristina Piselli; Anna Laura Pisello; Mohammad Saffari; Alvaro de Gracia; Franco Cotana; Luisa F. Cabeza;
    Publisher: MDPI
    Countries: Spain, Italy, Spain
    Project: EC | TECNIOspring PLUS (712949)

    Cool roof effectiveness in improving building thermal-energy performance is affected by different variables. In particular, roof insulation level and climate conditions are key parameters influencing cool roofs benefits and whole building energy performance. This work aims at assessing the role of cool roof in the optimum roof configuration, i.e., combination of solar reflectance capability and thermal insulation level, in terms of building energy performance in different climate conditions worldwide. To this aim, coupled dynamic thermal-energy simulation and optimization analysis is carried out. In detail, multi-dimensional optimization of combined building roof thermal insulation and solar reflectance is developed to minimize building annual energy consumption for heating-cooling. Results highlight how a high reflectance roof minimizes annual energy need for a small standard office building in the majority of considered climates. Moreover, building energy performance is more sensitive to roof solar reflectance than thermal insulation level, except for the coldest conditions. Therefore, for the selected building, the optimum roof typology presents high solar reflectance capability (0.8) and no/low insulation level (0.00-0.03 m), except for extremely hot or cold climate zones. Accordingly, this research shows how the classic approach of super-insulated buildings should be reframed for the office case toward truly environmentally friendly buildings. The work was partially funded by the Spanish government (RTI2018-093849-B-C31). This work was partially supported by ICREA under the ICREA Academia programme. Dr. Alvaro de Gracia has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia. This publication has emanated from research supported (in part) by Science Foundation Ireland (SFI) under the SFI Strategic Partnership Programme Grant Number SFI/15/SPP/E3125.

  • Open Access English
    Authors: 
    Lorenzo Ciani; Giulia Guidi; Gabriele Patrizi; Diego Galar;
    Publisher: MDPI AG
    Countries: Italy, Spain

    Reliability-centered maintenance (RCM) is a well-established method for preventive maintenance planning. This paper focuses on the optimization of a maintenance plan for an HVAC (heating, ventilation and air conditioning) system located on high-speed trains. The first steps of the RCM procedure help in identifying the most critical items of the system in terms of safety and availability by means of a failure modes and effects analysis. Then, RMC proposes the optimal maintenance tasks for each item making up the system. However, the decision-making diagram that leads to the maintenance choice is extremely generic, with a consequent high subjectivity in the task selection. This paper proposes a new fuzzy-based decision-making diagram to minimize the subjectivity of the task choice and preserve the cost-efficiency of the procedure. It uses a case from the railway industry to illustrate the suggested approach, but the procedure could be easily applied to different industrial and technological fields. The results of the proposed fuzzy approach highlight the importance of an accurate diagnostics (with an overall 86% of the task as diagnostic-based maintenance) and condition monitoring strategy (covering 54% of the tasks) to optimize the maintenance plan and to minimize the system availability. The findings show that the framework strongly mitigates the issues related to the classical RCM procedure, notably the high subjectivity of experts. It lays the groundwork for a general fuzzy-based reliability-centered maintenance method. This research received no external funding

  • Open Access English
    Authors: 
    Marina Fernández-Delgado Juárez; Ginevra Fabiani; Thomas Mazzier; Deborah Schönegger; Giacomo Pietramellara; María Gómez-Brandón; Heribert Insam;
    Publisher: Waste and Biomass Valorization
    Countries: Italy, Spain
    Project: EC | Residue2Heat (654650)

    Fast pyrolysis bio-oil (FPBO) is a liquid biofuel obtained from lignocellulosic residues. Moreover, biomass fly ashes (FAs) containing many minerals and micronutrients are obtained in the production process. Biomass ashes can be used as a lime substitute for amelioration of acid soils by increasing pH, providing nutrients for crop development and stimulating microbial activity. However, ash application might increase N-mineralization and induce nitrate losses via leaching. The main objective of this study was to investigate the applicability of FPBO-recovered FAs as soil amendment and their effects on soil microbial processes, plant development, and to evaluate the effects on soil leaching. In a greenhouse experiment, an acidic soil was amended with 2% of FAs and sown with a regional wheat variety. After 100 days, wheat was harvested and red clover was sown to simulate crop rotation. After 250 days, the soils were analysed microbiologically and physico-chemically. While no differences in plant yields were observed, FAs addition increased several soil chemical pools as well as certain microbiological parameters. Soil pH increased from 4.8 to 7.2, electrical conductivity from 89 to 407 µS cm−1, and the soil available P pool from 13.6 to 81.3 µg g−1 soil. Further, the nitrification rate, nitrate content in the soil leachates increased upon ash addition, in particular during the clover stage of the experiment. Summarized, despite not measurable effects on the plant growth, fly ash appears to enhance chemical and biological properties of soil cropped with wheat and clover without hinting towards negative environmental side-effects. Ministerio de Economía, Industria y Competitividad | Ref. RYC-2016–21231

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