328 research outputs found

    El Derecho de la Publicidad y sus garantías: la protección de la infancia y la juventud

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    Este artículo se presentó como comunicación en las VI Jornadas Internacionales de Ciencias de la Información de la Universidad de Navarra, celebradas en noviembre de 1991

    Building and exploiting a Digital Twin for the management of drinking water distribution networks

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    [EN] Digital Twins (DTs) are starting to be exploited to improve the management of water distribution systems (WDSs) and, in the future, they will be crucial for decision making. In this paper, the authors propose several requirements that a DT of a water distribution system should accomplish. Developing a DT is a challenge, and a continuous process of adjustments and learning is required. Due to the advantages of having a DT of the WDS always available, during the last years a strategy to build and maintain a DT of the water distribution network of Valencia (Spain) and its Metropolitan Area (1.6 million inhabitants) was developed. This is one of the first DTs built of a water utility, being currently in operation. The great benefits of their use in the daily operation of the system ensure that they will begin to be usual in the most advanced smart cities.Conejos Fuertes, P.; Martínez Alzamora, F.; Hervás-Carot, M.; Alonso Campos, JC. (2020). Building and exploiting a Digital Twin for the management of drinking water distribution networks. Urban Water Journal. 17(8):704-713. https://doi.org/10.1080/1573062X.2020.1771382S704713178Chacón Ramírez, E., Albarrán, J. C., & Cruz Salazar, L. A. (2019). The Control of Water Distribution Systems as a Holonic System. Studies in Computational Intelligence, 352-365. doi:10.1007/978-3-030-27477-1_27Grieves, M., et al. 2015. Virtually Intelligent Product Systems: Digital and Physical Twins. In Complex Systems Engineering: Theory and Practice, edited by S. Flumerfelt, et al., 175–200. American Institute of Aeronautics and Astronautics.Hatchett, S., J. Uber, D. Boccelli, T. Haxton, R. Janke, A. Kramer, A. Matracia, and S. Panguluri. 2011. “Real-Time Distribution System Modeling: Development, Application, and Insights.” Urban Water Management: Challenges and Oppurtunities - 11thInternational Conference on Computing and Control for the Water Industry, CCWI 2011 July.Kartakis, S., Abraham, E., & McCann, J. A. (2015). WaterBox. Proceedings of the 1st ACM International Workshop on Cyber-Physical Systems for Smart Water Networks. doi:10.1145/2738935.2738939Lin, J., Sedigh, S., & Miller, A. (2009). Towards Integrated Simulation of Cyber-Physical Systems: A Case Study on Intelligent Water Distribution. 2009 Eighth IEEE International Conference on Dependable, Autonomic and Secure Computing. doi:10.1109/dasc.2009.140Qi, Q., & Tao, F. (2018). Digital Twin and Big Data Towards Smart Manufacturing and Industry 4.0: 360 Degree Comparison. IEEE Access, 6, 3585-3593. doi:10.1109/access.2018.2793265Alac, M. (2008). Working with Brain Scans. Social Studies of Science, 38(4), 483-508. doi:10.1177/0306312708089715Shi, Y., Xu, J., & Du, W. (2019). Discussion on the New Operation Management Mode of Hydraulic Engineering Based on the Digital Twin Technique. Journal of Physics: Conference Series, 1168, 022044. doi:10.1088/1742-6596/1168/2/022044Tao, F., Zhang, H., Liu, A., & Nee, A. Y. C. (2019). Digital Twin in Industry: State-of-the-Art. IEEE Transactions on Industrial Informatics, 15(4), 2405-2415. doi:10.1109/tii.2018.2873186Tao, F., Cheng, J., Qi, Q., Zhang, M., Zhang, H., & Sui, F. (2017). Digital twin-driven product design, manufacturing and service with big data. The International Journal of Advanced Manufacturing Technology, 94(9-12), 3563-3576. doi:10.1007/s00170-017-0233-1Tao, F., & Qi, Q. (2019). Make more digital twins. Nature, 573(7775), 490-491. doi:10.1038/d41586-019-02849-1Uber, J., S. Hatchett, S. Hooper, D. Boccelli, H. Woo, and R. Janke. 2014. Water Utility Case Study of Real-Time Network Hydaulic and Water Qualilty Modeling Using EPANET-RTX Libraries. EPA 6007R-14/350 Report. Cincinnati, Ohio: Environmental Protection Agency.Wang, Z., Song, H., Watkins, D. W., Ong, K. G., Xue, P., Yang, Q., & Shi, X. (2015). Cyber-physical systems for water sustainability: challenges and opportunities. IEEE Communications Magazine, 53(5), 216-222. doi:10.1109/mcom.2015.710566

    Static magnetic order of Sr4_{4}A2_{2}O6_{6}Fe2_{2}As2_{2} (A = Sc and V) revealed by local probes

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    Static magnetic order of quasi two-dimensional FeAs compounds Sr4A2O6-xFe2As2, with A = Sc and V, has been detected by 57Fe Moessbauer and muon spin relaxation ({\mu}SR) spectroscopies. The non-superconducting stoichiometric (x = 0) A = Sc system exhibits a static internal/hyperfine magnetic field both at the 57Fe and {\mu}+ sites, indicating antiferromagnetic order of Fe moments below TN = 35 K with ~ 0.1 Bohr magneton per Fe at T = 2 K. The superconducting and oxygen deficient (x = 0.4) A = V system exhibits a static internal field only at the {\mu}+ site below TN ~ 40 K, indicating static magnetic order of V moments co-existing with superconductivity without freezing of Fe moments. These results suggest that the 42622 FeAs systems belong to the same paradigm with the 1111 and 122 FeAs systems with respect to magnetic behavior of Fe moments.Comment: 4 pages 4 figures: for information, contact [email protected]

    Compositional disorder and its influence on the structural, electronic and magnetic properties of MgC(Ni_{1-x}Co_{x})_{3} alloys using first-principles

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    First-principles, density-functional based electronic structure calculations are carried out for MgC(Ni_{1-x}Co_{x})_{3} alloys over the concentration range 0\leq x\leq1, using Korringa-Kohn-Rostoker coherent-potential approximation (KKR CPA) method in the atomic sphere approximation (ASA). The self-consistent calculations are used to study the changes as a function of x in the equation of state parameters, total and partial densities of states, magnetic moment and the on-site exchange interaction parameter. To study the magnetic properties as well as its volume dependence, fixed-spin moment calculations in conjunction with the phenomenological Landau theory are employed. The salient features that emerge from these calculations are (i) a concentration independent variation in the lattice parameter and bulk modulus at x~0.75 with an anomaly in the variation of the pressure derivative of bulk modulus, (ii) the fixed-spin moment based corrections to the overestimated magnetic ground state for 0.0\leq x\leq0.3 alloys, making the results consistent with the experiments, and (iii) the possibility of multiple magnetic states at x~0.75, which, however, requires further improvements in the calculations

    Synthesis of Poly[(3-(6-(9-anthracenylmethoxy)hexyl)thiophene)-co-(3-(6-bromohexyl)thiophene)] Postfunctionalized from Poly(3-(6-bromohexyl)thiophene): A Comparative Study of the Base Polymer with Its Chlorinated Analogous

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    A synthetic method based on the postfunctionalization of a reactive homopolymer precursor, which allows for the preparation of different copolymers derived from poly(3-alkylthiophene), was studied. Although these groups decrease the solubility of the resultant material, they enable controlling the degree of substitution to obtain a material with improved spectroscopic (absorption and emission) properties making them useful for the fabrication of electronic devices, for example, solar cells and light-emitting diodes. Furthermore, a comparative study of two halogenated (Cl and Br) reactive poly(3-ω-haloalkyl)thiophenes was carried out

    Modelling the influence of radiata pine log variables on structural lumber production

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    We run logit models to explain the variability of Pinus radiata structural lumber in 71 second and third unpruned logs. The response variable was the proportion of lumber with a static modulus of elasticity greater or equal than 8 GPa, pMSG8+, and the explanatory variables were log volume, branch index, largest branch, log internode index, wood basic density, and acoustic velocity. The average pMSG8+ volume was 44,30 % and 36,18 % in the second and third log respectively. Ten models were selected based on meeting statistical assumptions, their goodness of fit, and the statistical significance of their parameters. The best models (R2 - adj. > 0,75) included acoustic velocity (AV) as explanatory variable, which explained 56,25 % of the variability of pMSG8+. Models without AV presented goodness of fit ranging from 0,60 to 0,75 (R2 - adj.), and variables with the highest weight to explain the variability of pMSG8+ were volume, followed by wood basic density, branch index, and largest branch. It is possible to model pMSG8+ from log variables even when acoustic velocity is not available; however, this requires wood basic density models calibrated for the Pinus radiata growing zone

    Post-earthquake Reconnaissance Report on Transportation Infrastructure Impact of the February 27, 2010, Offshore Maule Earthquake in Chile

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    This report documents the findings and lessons learned from the February 27, 2010, M8.8 offshore Maule earthquake in Chile. Fewer than 0.15 percent of the bridges in Chile\u27s inventory, most built after 1995, collapsed or suffered damage that rendered them useless. Many spans of precast prestressed discontinuous girder bridges with continuous decks fell off their supports, probably due to significant in-plane rotation of the superstructure as a result of severe shaking. Lateral steel stoppers used to provide both vertical and lateral restraints on girders were largely unsuccessful due to their inadequate connection detail to cap beams and abutments. Reinforced concrete shear keys performed well as fuses limiting the transfer of excessive seismic loads from the superstructure to the foundation of bridges even though they could be optimized for maximum energy dissipation as part of the lateral restraint system at the bottom flange of girders. Vertical seismic bars were widely used to restrain the vertical motion of decks, and they also performed well. Bridge substructures (foundation, column, and cap beam) generally behaved satisfactorily except for two columns that suffered shear failure due to ground settlement and lateral spreading. All mechanically stabilized earth walls exceeded the expected performance

    Antiferromagnetic Order and Superconductivity in Sr4(Mg0.5-xTi0.5+x)2O6Fe2As2 with Electron Doping: 75As-NMR Study

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    We report an 75As-NMR study on iron (Fe)-based superconductors with thick perovskitetype blocking layers Sr4(Mg0.5-xTi0.5+x)2O6Fe2As2 with x=0 and 0.2. We have found that antiferromagnetic (AFM) order takes place when x=0, and superconductivity (SC) emerges below Tc=36 K when x=0.2. These results reveal that the Fe-pnictides with thick perovskitetype blocks also undergo an evolution from the AFM order to the SC by doping electron carriers into FeAs planes through the chemical substitution of Ti+4 ions for Mg+2 ions, analogous to the F-substitution in LaFeAsO compound. The reason why the Tc=36 K when x=0.2 being higher than the optimally electron-doped LaFeAsO with Tc=27 K relates to the fact that the local tetrahedron structure of FeAs4 is optimized for the onset of SC.Comment: 4 pages, 3 figures, 1 tabl
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