280 research outputs found

    Monitoring and mapping soil functionality in degraded areas of organic European vineyards

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    Soil malfunctioning, caused by an improper land preparation before vine plantation and/or management, is a common problem in European vineyards. Soil malfunctioning can include: reduced contribution of the soil fauna, poor organic matter content, imbalance nutritional status, altered pH, water deficiency, soil compaction and/or scarce oxygenation. To address these problems, ReSolVe, a transnational European research project, aimed at testing the effects of selected agronomic strategies for restoring optimal soil functionality in degraded areas within organic vineyard. The project involves 8 research groups in 6 different EU countries (Italy, Spain, France, Sweden, Slovenia, and Turkey) with experts from several disciplines including soil science, ecology, microbiology, grapevine physiology, viticulture, and biometry. The experimental vineyards are situated in Italy (Chianti hills and Maremma plain, Tuscany), Spain (La Rioja), France (Bordeaux and Languedoc), and Slovenia (Primorska) for winegrapes, and in Turkey (Adana and Mersin) for tablegrapes. Three different restoring strategies have been implemented: (i) compost, (ii) green manure with winter legumes, and (iii) dry mulching with cover crops. These strategies have being tested according to their efficiency to improve i) plant and root growth; and ii) grape yield and quality; optimize iii) the quality of soil ecosystem services; and iv) the terroir effect. The first activity of the project was characterizing and mapping the degraded areas within experimental vineyards. In the work we used non-invasive technologies to characterize soil and plant status. In Spanish and Italian vineyards, the delineation of degraded areas was performed by gamma-ray spectroscopy for topsoil, RGB machine vision for canopy status and thermography for plant water status. Gamma-ray spectroscopy measured continuously the natural gamma-ray emitted from the first 30-40 cm of soil, calculating the contribution of the main radionuclides (40K, 232Th, and 238U). The spectra of gamma-ray were able to provide information about mineralogy, texture, surficial stoniness and carbonates. RGB and thermal cameras were used to assess canopy porosity, leaf area exposure and vine water status of both degraded and non-degraded areas. All soil, canopy and water status parameters were mapped

    The XMM-Newton survey of the Small Magellanic Cloud: XMMUJ005011.2-730026 = SXP214, a Be/X-ray binary pulsar

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    In the course of the XMM-Newton survey of the Small Magellanic Cloud (SMC), a region to the east of the emission nebula N19 was observed in November 2009. To search for new candidates for high mass X-ray binaries the EPIC PN and MOS data of the detected point sources were investigated and their spectral and temporal characteristics identified. A new transient (XMMUJ005011.2-730026= SXP214) with a pulse period of 214.05 s was discovered; the source had a hard X-ray spectrum with power-law index of ~0.65. The accurate X-ray source location permits the identification of the X-ray source with a ~15th magnitude Be star, thereby confirming this system as a new Be/X-ray binary.Comment: 8 pages 11 figures. Accepted for publication in MNRA

    X-ray detection with Micromegas with background levels below 106^{-6} keV1^{-1}cm2^{-2}s1^{-1}

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    Micromegas detectors are an optimum technological choice for the detection of low energy x-rays. The low background techniques applied to these detectors yielded remarkable background reductions over the years, being the CAST experiment beneficiary of these developments. In this document we report on the latest upgrades towards further background reductions and better understanding of the detectors' response. The upgrades encompass the readout electronics, a new detector design and the implementation of a more efficient cosmic muon veto system. Background levels below 106^{-6}keV1^{-1}cm2^{-2}s1^{-1} have been obtained at sea level for the first time, demonstrating the feasibility of the expectations posed by IAXO, the next generation axion helioscope. Some results obtained with a set of measurements conducted in the x-ray beam of the CAST Detector Laboratory will be also presented and discussed

    Photometric and spectroscopic variability of the B5IIIe star HD 171219

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    We analyzed the star HD171219, one of the relatively bright Be stars observed in the seismo field of the CoRoT satellite, in order to determine its physical and pulsation characteristics. Classical Be stars are main-sequence objects of mainly B-type, whose spectra show,or have shown at some epoch, Balmer lines in emission and an infrared excess. Both characteristics are attributed to an equatorially concentrated circumstellar disk fed by non-periodic mass-loss episodes (outbursts). Be stars often show nonradial pulsation gravity modes and, as more recently discovered, stochastically excited oscillations. Applying the CLEANEST algorithm to the high-cadence and highly photometrically precise measurements of the HD171219 light curve led us to perform an unprecedented detailed analysis of its nonradial pulsations. Tens of frequencies have been detected in the object compatible with nonradial g-modes. Additional ighresolution ground-based spectroscopic observations were obtained at La Silla (HARPS) and Haute Provence (SOPHIE) observatories during the month preceding CoRoT observations. Additional information was obtained from low-resolution spectra from the BeSS database. From spectral line fitting we determined physical parameters of the star, which is seen equator-on (i = 90 ). We also found in the ground data the same frequencies as in CoRoT data. Additionally, we analyzed the circumstellar activity through the traditional method of violet to red emission H line variation. A quintuplet was identified at approximately 1:113 c d\u1000001 (12.88 Hz) with a separation of 0:017 c d\u1000001 that can be attributed to a pulsation degree ` 2. The light curve shows six small- to medium-scale outbursts during the CoRoT observations. The intensity of the main frequencies varies after each outburst, suggesting a possible correlation between the nonradial pulsations regime and the feeding of the envelope
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