450 research outputs found

    Universidad de Navarra = 0 CO2

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    Un proyecto académico, realizado por alumnos de la Escuela de Arquitectura de la Universidad de Navarra durante el curso 2008-2009, derivó en una ambiciosa actuación propositiva para que en el Campus de la Universidad de Navarra en Pamplona se minimizaran las emisiones de CO2. Las ideas propuestas incluyen acciones relacionadas con el transporte, la gestión del agua, la gestión de residuos,… Es objeto de esta comunicación exponer la metodología seguida en el proyecto, así como los principales resultados obtenidos en distintas áreas

    Innovative instrumentation and methodology to characterize long distance heliostat beam quality in commercial solar power tower plants

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    The characterization of the whole solar field of a solar tower power plant is a time consuming labor that has to be performed to know the optical quality of each heliostat in the field. This allows to correct some deviations of each heliostat, leading to an improvement in its individual performance, and thus, improving the final performance of the whole field. The current methodology to characterize the optical quality of a heliostat is based on using a lambertian target, in which the solar beam is focused and its reflected radiation is captured using cameras. This leads to important measurement inaccuracies due to the non-uniformity of the lambertian target and the behavior of the camera. But the fact that the sun beam can overflow the size of the target, and its power density can be almost in the order of the ambient light, implies that a huge part of the heliostats in a plant cannot be well-characterized by these systems. These issues are even more important taking into account that plant size tends to grow even larger, increasing the distance of the furthest heliostats, and that small heliostats begin to be introduced in solar fields, whose reflected power is lower than that of common heliostats. Those issues will be overcome thanks to a new measurement system based on a non-tracking way to scan the sun spot, using an array of optoelectronic detectors which can be installed in new plants and even in plants that are now in operation

    HAPLÓS/Bisensorial EXHIBIT: A Speculative, Adaptive, and Wearable Technology for Inducing Mental States Using Touch

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    How might cognitive wellness and therapeutic practices look in the future? Can mental discord be treated autonomously? Given that people are different and will therefore need different interventions, how can autonomous brain based therapy technologies be tailored to suit the needs of individuals at any given time? This exhibit suggests one potential future of therapeutic treatment and what this future looks like right now. HAPLÓS/Bisensorial is a speculative design concept and functioning prototype of wearable technology based on research in embodied cognition, somatic learning, and the effect of sound on cognitive processes. It uses binaural sound and tactile vibration on your back to induce mental states - such as calm. A genetic algorithm generates patterns of auditory and tactile stimuli, based on readings provided by an EEG headset. The result is intended to be an optimized and personalised soundscape and ‘touchscape’ that adjusts to your needs. HAPLÓS/Bisensorial is being developed at Plymouth University as part of the CogNovo programme. More information: https://cognovo.eu/events/otlip16- bizarre-bazaar.ph

    Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

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    Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured

    Ultrarelativistic sources in nonlinear electrodynamics

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    The fields of rapidly moving sources are studied within nonlinear electrodynamics by boosting the fields of sources at rest. As a consequence of the ultrarelativistic limit the delta-like electromagnetic shock waves are found. The character of the field within the shock depends on the theory of nonlinear electrodynamics considered. In particular, we obtain the field of an ultrarelativistic charge in the Born-Infeld theory.Comment: 10 pages, 3 figure

    Search for Branons at LEP

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    We search, in the context of extra-dimension scenarios, for the possible existence of brane fluctuations, called branons. Events with a single photon or a single Z-boson and missing energy and momentum collected with the L3 detector in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are analysed. No excess over the Standard Model expectations is found and a lower limit at 95% confidence level of 103 GeV is derived for the mass of branons, for a scenario with small brane tensions. Alternatively, under the assumption of a light branon, brane tensions below 180 GeV are excluded

    Measurement of the Cross Section for Open-Beauty Production in Photon-Photon Collisions at LEP

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    The cross section for open-beauty production in photon-photon collisions is measured using the whole high-energy and high-luminosity data sample collected by the L3 detector at LEP. This corresponds to 627/pb of integrated luminosity for electron-positron centre-of-mass energies from 189GeV to 209GeV. Events containing b quarks are identified through their semi-leptonic decay into electrons or muons. The e+e- -> e+e-b b~X cross section is measured within our fiducial volume and then extrapolated to the full phase space. These results are found to be in significant excess with respect to Monte Carlo predictions and next-to-leading order QCD calculations

    Search for Charginos with a Small Mass Difference with the Lightest Supersymmetric Particle at \sqrt{s} = 189 GeV

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    A search for charginos nearly mass-degenerate with the lightest supersymmetric particle is performed using the 176 pb^-1 of data collected at 189 GeV in 1998 with the L3 detector. Mass differences between the chargino and the lightest supersymmetric particle below 4 GeV are considered. The presence of a high transverse momentum photon is required to single out the signal from the photon-photon interaction background. No evidence for charginos is found and upper limits on the cross section for chargino pair production are set. For the first time, in the case of heavy scalar leptons, chargino mass limits are obtained for any \tilde{\chi}^{+-}_1 - \tilde{\chi}^0_1 mass difference

    Direct Observation of Longitudinally Polarised W Bosons

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    The three different helicity states of W bosons, produced in the reaction e+e- -> W+W- -> l nu q q~ are studied using leptonic and hadronic W decays at sqrt{s}=183GeV and 189GeV. The W polarisation is also measured as a function of the scattering angle between the W- and the direction of the e- beam. The analysis demonstrates that W bosons are produced with all three helicities, the longitudinal and the two transverse states. Combining the results from the two center-of-mass energies and with leptonic and hadronic W decays, the fraction of longitudinally polarised W bosons is measured to be 0.261 +/- 0.051(stat.) +/- 0.016(syst.) in agreement with the expectation from the Standard Model
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