159 research outputs found

    Construcción de esculturas de hormigón con elementos procedentes del reciclado

    Get PDF
    This paper shows the conceptual development, project, constructive and execution processes of a group of seven sculptures designed to act as containers of other art works carried out by the Spanish artist Jesús Soler. This sculptural group bases its message on the sustainability and the recycling of materials. Its fundamental boundary conditions are the capacity to be mounted and dismounted without any anchorage to the soil, durability and protection of the art work in front of meteorological agents. The sculptural group transmits by itself an environmental message. This paper describes the geometry and proportions, based on the “Le Corbusier Modulor” and the golden section, as well as all the constructive techniques applied for the correct design of each sculpture: formwork systems, concrete with recycled arid, corten steel frames, anchorages, etc. Finally the first assembly process of this itinerant sculptural work is described; it is mounted in the Parque del Retiro in the city of Madrid (Spain).Este trabajo recoge el desarrollo conceptual, de proyecto, construcción y de ejecución de un conjunto de siete esculturas disenadas para actuar como contenedores de otras obras de arte (17 cuadros) realizadas por el artista Jesús Soler. Este conjunto escultórico basa su mensaje en la sostenibidad y el reciclaje. Presenta, como condiciones de contorno fundamentales, la capacidad de ser montado y desmontado sin necesidad de anclar al terreno, durabilidad y protección de las obras frente a agentes meteorológicos y todo ello transmitiendo por sí mismas un mensaje medioambiental. Se describe en el documento la geometría y proporciones basadas en el “Modulor” de Le Corbusier y, por consiguiente, en la sección áurea, así como todas las técnicas constructivas aplicadas para el correcto diseno de cada obra: sistemas de encofrado, hormigones con áridos reciclados, marcos de acero corten, anclajes, etc. Finalmente se describe el primer proceso de montaje de esta obra itinerante, en el Parque del Retiro de Madrid

    El género Lysaphidus (Hymenoptera: Braconidae) en la Península Ibérica

    Get PDF
    The genus Lysaphidus Smith, 1944 (Hymenoptera, Braconidae, Aphidiinae) is recorded for the first time from the Iberian Peninsula represented by two species: L. arvensis Stary, 1960, first record for the Iberian Peninsula, and L. santolinae n. sp., both of them parasitoids of Coloradoa Wilson,1910 genus (Homoptera, Aphididae). The mummies were collected on Santolina chamaecyparissus L. and Santolina rosmarinifolia L. (Asteraceae).Se detecta la presencia del género Lysaphidus Smith, 1944 (Hymenoptera, Braconidae, Aphidiinae) en la Península Ibérica, representado por dos especies, L. arvensis Stary, 1960, nueva cita para la Peninsula Ibérica y L. santolinae n. sp., parasitoides ambos del género Coloradoa Wilson, 1910 (Homoptera, Aphididae), cuyas momias fueron recolectadas sobre Santolina chamaecyparissus L. y Santolina rosmarinifolia L. (Asteraceae)

    Nineteen-port photonic lantern with multimode delivery fiber

    Get PDF
    We demonstrate efficient multimode (MM) to single-mode (SM) conversion in a 19-port photonic lantern with a 50 μm core MM delivery fiber. The photonic lantern can be used within the field of astrophotonics for coupling MM starlight to an ensemble of SM fibers in order to perform fiber-Bragg-grating-based spectral filtering. An MM delivery fiber spliced to the photonic lantern offers the advantage that the delivery fiber guides the light from the focal plane of the telescope to the splitter. Therefore, it is no longer necessary to have the splitter mounted directly in the focal plane of the telescope. The coupling loss from a 50 μm core MM fiber to an ensemble of 19 SM fibers and back to a 50 μm core MM fiber is below 1.1 dB.3 page(s

    Suppression of the near-infrared OH night sky lines with fibre Bragg gratings - first results

    Get PDF
    The background noise between 1 and 1.8 microns in ground-based instruments is dominated by atmospheric emission from hydroxyl molecules. We have built and commissioned a new instrument, GNOSIS, which suppresses 103 OH doublets between 1.47 - 1.7 microns by a factor of ~1000 with a resolving power of ~10,000. We present the first results from the commissioning of GNOSIS using the IRIS2 spectrograph at the AAT. The combined throughput of the GNOSIS fore-optics, grating unit and relay optics is ~36 per cent, but this could be improved to ~46 per cent with a more optimal design. We measure strong suppression of the OH lines, confirming that OH suppression with fibre Bragg gratings will be a powerful technology for low resolution spectroscopy. The integrated OH suppressed background between 1.5 and 1.7 microns is reduced by a factor of 9 compared to a control spectrum using the same system without suppression. The potential of low resolution OH suppressed spectroscopy is illustrated with example observations. The GNOSIS background is dominated by detector dark current below 1.67 microns and by thermal emission above 1.67 microns. After subtracting these we detect an unidentified residual interline component of ~ 860 +/ 210 ph/s/m^2/micron/arcsec^2. This component is equally bright in the suppressed and control spectra. We have investigated the possible source of the interline component, but were unable to discriminate between a possible instrumental artifact and intrinsic atmospheric emission. Resolving the source of this emission is crucial for the design of fully optimised OH suppression spectrographs. The next generation OH suppression spectrograph will be focussed on resolving the source of the interline component, taking advantage of better optimisation for a FBG feed. We quantify the necessary improvements for an optimal OH suppressing fibre spectrograph design.Comment: Accepted for publication in MNRAS. 15 pages, 18 figure

    The Sydney-AAO Multi-object Integral field spectrograph (SAMI)

    Full text link
    We demonstrate a novel technology that combines the power of the multi-object spectrograph with the spatial multiplex advantage of an integral field spectrograph (IFS). The Sydney-AAO Multi-object IFS (SAMI) is a prototype wide-field system at the Anglo-Australian Telescope (AAT) that allows 13 imaging fibre bundles ("hexabundles") to be deployed over a 1-degree diameter field of view. Each hexabundle comprises 61 lightly-fused multimode fibres with reduced cladding and yields a 75 percent filling factor. Each fibre core diameter subtends 1.6 arcseconds on the sky and each hexabundle has a field of view of 15 arcseconds diameter. The fibres are fed to the flexible AAOmega double-beam spectrograph, which can be used at a range of spectral resolutions (R=lambda/delta(lambda) ~ 1700-13000) over the optical spectrum (3700-9500A). We present the first spectroscopic results obtained with SAMI for a sample of galaxies at z~0.05. We discuss the prospects of implementing hexabundles at a much higher multiplex over wider fields of view in order to carry out spatially--resolved spectroscopic surveys of 10^4 to 10^5 galaxies.Comment: 24 pages, 16 figures. Accepted by MNRA
    corecore