3,501 research outputs found
Catálogo florĂstico de la provincia de Málaga. I. "Selaginellaceae" - "Ephedraceae"
Este trabajo es el primero de una serie cuyo fin es la publicaciĂłn del catálogo florĂstico completo de la provincia de Málaga. En esta primera nota se incluyen los datos recogidos sobre la provincia de Málaga en las especies comprendidas desde Selaginellaceae a Ephedraceae, asĂ como una reseña histĂłrica de las herborizaciones en la provincia. Las citas de especie van acompañadas de su localizaciĂłn en el retĂculo internacional U.T.M., las citas bibliográficas llevan su correspondiente reseña
ContribuciĂłn a la palinologĂa de Liliaceae en AndalucĂa Occidental (excepto subfamilias Scilloideae y Allioideae)
Se estudia la morfol ogĂa del polen de 23 especies de Liliaceae en Andal ucĂa Occidental, pertenecientes a los gĂ©neros Asphodelus, Anthericum, Simethis, Aphyllanthes, Colchicum, Merendera, Gag ea , Tulipa, Fri tillarĂa, Po!ygonatum, Asparagus, Ruscus y Smilax. Por l os caracteres polinices analizados se reconocen 14 tipos diferentes . PalinolĂłgicamente está justificada la separaciĂłn de Smilacoideae como familia independiente , pero no se justifica la separaciĂłn de Liliaceae y AmaryllidaceaeThe pollen morphol ogy of 23 species of Liliaceae from W. AndalucĂa belonging to the genera Asphodelus, Anthericum, Simethis, Aphyllanthes, Colchicum , Merendera, Gagea, Tulipa , Fritillaria, Polygonatum, Asparagus, Ruscus and Smilax have been studied. Fourteen types of pollen grains have been found, which are more or l ess in accordance wi t h the accepted genera . The palynol ogical data agree wi th the separation o f Smila9oideae as a different family. The tradi ti anal separation of Liliaceae a nd Amaryllidaceae is not justificd palynologicall
Estructura de algunas comunidades vegetales de dunas en el litoral de Marbella (Málaga)
In this work, is described the structure of the vegetation of dunes of the seashore of Marbella (Málaga), and are made several samples of the main plant communities. Those communities are placed in their phytocoenological entities, following a synoptic form. For the first time, are described two new phytosociological associations: Malcolmio-Vulpietum alopecuri and Sporobolo-Centaureetum sphaerocephalae. Is presented a block scheme of the different communities and their structural relationships
Bases para la confecciĂłn del atlas florĂstico de la provincia de Málaga
Se examinan los atlas florĂsticos hechos Ăşltimamente en Europa, especialmente los que siguen la cuadrĂcula UTM, y se comentan las caracterĂsticas de cada uno de ellos. A continuaciĂłn se señalan los criterios que se han seguido para la elaboraciĂłn del plano matriz, en cuadrĂcula UTM, para la provincia de Málaga, y los trabajos que se siguen, a fin de hacer el correspondiente atlas florĂstico
A skewer survey of the Galactic halo from deep CFHT and INT images
We study the density profile and shape of the Galactic halo using deep
multicolour images from the MENeaCS and CCCP projects, over 33 fields selected
to avoid overlap with the Galactic plane. Using multicolour selection and PSF
homogenization techniques we obtain catalogues of F stars (near-main sequence
turnoff stars) out to Galactocentric distances up to 60kpc. Grouping nearby
lines of sight, we construct the stellar density profiles through the halo in
eight different directions by means of photometric parallaxes. Smooth halo
models are then fitted to these profiles. We find clear evidence for a
steepening of the density profile power law index around R=20 kpc, from -2.50
+- 0.04 to -4.85 +- 0.04, and for a flattening of the halo towards the poles
with best-fit axis ratio 0.63 +- 0.02. Furthermore, we cannot rule out a mild
triaxiality (w>=0.8). We recover the signatures of well-known substructure and
streams that intersect our lines of sight. These results are consistent with
those derived from wider but shallower surveys, and augur well for upcoming,
wide-field surveys of comparable depth to our pencil beam surveys.Comment: 14 pages, 8 figures, 6 table
Finding halo streams with a pencil-beam survey: new wraps in the Sagittarius stream
We use data from two CFHT-MegaCam photometric pencil-beam surveys in the g'
and the r' bands to measure distances to the Sagittarius, the Palomar 5 and the
Orphan stream. We show that, using a cross-correlation algorithm to detect the
turnoff point of the main sequence, it is possible to overcome the main
limitation of a two-bands pencil-beam survey, namely the lack of adjacent
control-fields that can be used to subtract the foreground and background stars
to enhance the signal on the colour-magnitude diagrams (CMDs). We describe the
cross-correlation algorithm and its implementation. We combine the resulting
main sequence turnoff points with theoretical isochrones to derive photometric
distances to the streams. Our results (31 detections on the Sagittarius stream
and one each for the Palomar 5 and the Orphan streams) confirm the findings by
previous studies, expand the distance trend for the Sagittarius faint southern
branch and, for the first time, trace the Sagittarius faint branch of the
northern-leading arm out to 56 kpc. In addition, they show evidence for new
substructure: we argue that these detections trace the continuation of the
Sagittarius northern-leading arm into the southern hemisphere, and find a
nearby branch of the Sagittarius trailing wrap in the northern hemisphere.Comment: 16 pages, 15 figures, 2 table
Air gap influence on the vibro-acoustic response of Solar Arrays during launch
One of the primary elements on the space missions is the electrical power subsystem, for which the critical component is the solar array. The behaviour of these elements during the ascent phase of the launch is critical for avoiding damages on the solar panels, which are the primary source of energy for the satellite in its final configuration. The vibro-acoustic response to the sound pressure depends on the solar array size, mass, stiffness and gap thickness. The stowed configuration of the solar array consists of a multiple system composed of structural elements and the air layers between panels. The effect of the air between panels on the behaviour of the system affects the frequency response of the system not only modifying the natural frequencies of the wings but also as interaction path between the wings of the array. The usual methods to analyze the vibro-acoustic response of structures are the FE and BE methods for the low frequency range and the SEA formulation for the high frequency range. The main issue in the latter method is, on one hand, selecting the appropriate subsystems, and, on the other, identifying the parameters of the energetic system: the internal and coupling loss factors. From the experimental point of view, the subsystems parameters can be identified by exciting each subsystem and measuring the energy of all the subsystems composing the Solar Array. Although theoretically possible, in practice it is difficult to apply loads on the air gaps. To analyse this situation, two different approaches can be studied depending on whether the air gaps between the panels are included explicitly in the problem or not. For a particular case of a solar array of three wings in stowed configuration both modelling philosophies are compared. This stowed configuration of a three wing solar arrays in stowed configuration has been tested in an acoustic chamber. The measured data on the solar wings allows, in general, determining the loss factors of the configuration. The paper presents a test description and measurements on the structure, in terms of the acceleration power spectral density. Finally, the performance of each modelling technique has been evaluated by comparison between simulations with experimental results on a spacecraft solar array and the influence on the apparent properties of the system in terms of the SEA loss factors has been analyse
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