11,542 research outputs found

    Distribución y ecología de Echinospartum horridum (Vahl) Rothm. en Navarra.

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    Se ha estudiado la distribución y el habitat de Echinospartum horridum (Vahl) Rothm. (Genista hórrida (Vahl) D.C.) en la provincia de Navarra

    Estudio del polen atmosférico primaveral de la ciudad de Pamplona

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    El presente trabajo es un estudio del polen presente en la atmósfera de Pamplona, recogido diariamente durante los meses de marzo, abril, mayo, junio de 1978. Abstract: The spring atmospherical pollen of Pamplona is studied in this work. The pollen has been collected everyday during spring´s months of March, April, May, June in 1978

    Mid-infrared imaging- and spectro-polarimetric subarcsecond observations of NGC 1068

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    We present sub-arcsecond 7.5-13 μ\mum imaging- and spectro-polarimetric observations of NGC 1068 using CanariCam on the 10.4-m Gran Telescopio CANARIAS. At all wavelengths, we find: (1) A 90 ×\times 60 pc extended polarized feature in the northern ionization cone, with a uniform \sim44^{\circ} polarization angle. Its polarization arises from dust and gas emission in the ionization cone, heated by the active nucleus and jet, and further extinguished by aligned dust grains in the host galaxy. The polarization spectrum of the jet-molecular cloud interaction at \sim24 pc from the core is highly polarized, and does not show a silicate feature, suggesting that the dust grains are different from those in the interstellar medium. (2) A southern polarized feature at \sim9.6 pc from the core. Its polarization arises from a dust emission component extinguished by a large concentration of dust in the galaxy disc. We cannot distinguish between dust emission from magnetically aligned dust grains directly heated by the jet close to the core, and aligned dust grains in the dusty obscuring material surrounding the central engine. Silicate-like grains reproduce the polarized dust emission in this feature, suggesting different dust compositions in both ionization cones. (3) An upper limit of polarization degree of 0.3 per cent in the core. Based on our polarization model, the expected polarization of the obscuring dusty material is \lesssim0.1 per cent in the 8-13 μ\mum wavelength range. This low polarization may be arising from the passage of radiation through aligned dust grains in the shielded edges of the clumps.Comment: 17 pages, 10 figures, accepted for publication at MNRA

    Experimental aspects of SU(5)xU(1) supergravity

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    We study various aspects of SU(5)×U(1)SU(5)\times U(1) supergravity as they relate to the experimental verification or falsification of this model. We consider two string-inspired, universal, one-parameter, no-scale soft-supersymmetry-breaking scenarios, driven by the FF-terms of the moduli and dilaton fields. The model is described in terms of the supersymmetry mass scale (\ie, the chargino mass mχ1±m_{\chi^\pm_1}), tanβ\tan\beta, and the top-quark mass. We first determine the combined effect on the parameter space of all presently available direct and indirect experimental constraints, including the LEP lower bounds on sparticle and Higgs-boson masses, the bsγb\to s\gamma rate, the anomalous magnetic moment of the muon, the high-precision electroweak parameters ϵ1,ϵb\epsilon_1,\epsilon_b (which imply m_t\lsim180\GeV), and the muon fluxes in underground detectors (neutrino telescopes). For the still-allowed points in (mχ1±,tanβ)(m_{\chi^\pm_1},\tan\beta) parameter space, we re-evaluate the experimental situation at the Tevatron, LEPII, and HERA. In the 1994 run, the Tevatron could probe chargino masses as high as 100 GeV. At LEPII the parameter space could be explored with probes of different resolutions: Higgs boson searches, selectron searches, and chargino searches. Moreover, for m_t\lsim150\GeV, these Higgs-boson searches could explore all of the allowed parameter space with \sqrt{s}\lsim210\GeV.Comment: latex, 36 pages, 25 figures (not included). Figures are available via anonymous ftp from hplaa02.cern.ch (/pub/lopez) as either 33 ps files (Easpects*.ps, 8.1MB) or one uuencoded file (AllFigures.uu, 3.7MB

    Cosmological Constraints and SU(5) Supergravity Grand Unification

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    The predictions of SU(5) supergravity models with radiative breaking constrained by experimental proton decay bounds are discussed. It is shown that cosmological constraints further restrict the parameter space but can be satisfied for a wide range of parameters. It is also shown that no serious fine tuning problems (either at MSUSYM_{SUSY} or MGUTM_{GUT}) exist.Comment: 11page

    Wave farm planning through high-resolution resource and performance characterization

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    Wave farm planning in a coastal region should lead to the selection of: i) the type of technology of wave energy converter (WEC) providing the highest performance at specific sites and ii) the sites for wave farm operation allowing an integrated coastal zone management (ICZM). On these bases, the deployment of a wave farm should be based on an accurate analysis of the performance of different WECs at coastal locations where wave energy exploitation does not interfere with other coastal uses, and the environmental impact is minimised (or positive, e.g. allowing coastal protection). With this in view, in this piece of research the intra-annual performance of various WECs of the same type (buoy-type) is computed at different locations in NW Spain allowing an ICZM perspective. For this purpose, the intra-annual version of WEDGE-p® (Wave Energy Diagram Generator – performance) tool is implemented. The results show that, as opposed to previous analysis on WECs with different principle of operation, the level of performance of buoy-type WECs at specific locations may present strong similarities. In this case, an accurate computation of different performance parameters along with their joint analysis emerge as a prerequisite for an informed decision-making
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