1,475 research outputs found

    “Four machines for sod-seeding in comparison: first results of operational and technical tests in Basilicata”

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    Our study was carried out to evaluate four different seeders for sod-seeding by a qualitative and quantitative comparison of their performances on cereal crops in Basilicata. The application of sod-seeding, alias no tillage, it may represent a valid alternative to traditional seeding in areas with high cereal vocation, as a guarantee against production costs, safeguarding the productive and environmentalists aspects in the south of Italy, where there is a great crop specialization and higher environmental risk resulting from intensive farming operations. So, were organized tests with four different seeders: Gaspardo-Directa, Amazone AD 300, Alpego ASI 303 and Laseminasodo. We analysed the technical and operational characteristics of the seeders, the distribution regularity of the seed and the parameters concerning the harvesting. Relating to this study, the most important difference, between these machines we considered, was the coulter body. The results were interesting for all machines, the operational capabilities have been certified on values equal to 1,8 ha/h, satisfactory values regularity of longitudinal and transverse distribution of the seed considering that the value of plants emergency was close to 90%. About yield obtained, some data collected showed a higher value compared with that obtained with the traditional seeding in the same soil conditions

    Satellite guidance systems in agriculture: experimental comparison between EZ-Steer/RTK and AUTOPILOT/EGNOS

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    The research has been conducted using two different satellite-guidance devices and two different correction systems of the GPS signal: the EZ-Steer/RTK and Autopilot/EGNOS. The machines used in the tests were the tractor New Holland T7060, the rotary harrow Alpego DG-400 and the burier Forigo DG-45, in order to determine which of the two systems ensured the best quality of work. On the basis of the results obtained it is clear that the EZ-Steer/RTK system, guarantees a lower stability of the theoretical trajectory compared to the Autopilot/EGNOS system, above 1,77%. From the elaboration of data of the two guidance systems behavior to manage the only width of transposition, it is observed that the EZ-Steer/RTK system is able to guarantee a better hold of the line compared to the Autopilot/EGNOS system, which provides a mistake of 164 cm on the total width of transposition and 2 cm on the mean value. In the matter of the normalized transposition surfaces, the Autopilot/EGNOS system ensures a better work quality

    An intrusion and fault tolerant forensic storage for a SIEM system

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    Current Security Information and Events Management (SIEM) solutions lack a data storage facility which is secure enough - i.e. stored events related to security incidents cannot be forged and are always available - that it can be used for forensic purposes. Forensic storage used by current SIEM solutions uses traditional RSA algorithm to sign the security events. In this paper we have analyzed the limits of current forensic storages, and we have proposed an architecture for forensic storage, implementing a threshold-based variant of the RSA algorithm, that outperforms state of the art SIEM solutions in terms of intrusion- and fault-tolerance. We show by experiments that our forensic storage works correctly even in the presence of cyber-attacks, although with a performance penalty. We also conduct an experimental campaign to evaluate the performance cost of the proposed scheme as a function of the threshold

    An improved algorithm for narrow-band searches of continuous gravitational waves

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    Continuous gravitational waves signals, emitted by asymmetric spinning neutron stars, are among the main targets of current detectors like Advanced LIGO and Virgo. In the case of sources, like pulsars, which rotational parameters are measured through electromagnetic observations, typical searches assume that the gravitational wave frequency is at a given known fixed ratio with respect to the star rotational frequency. For instance, for a neutron star rotating around one of its principal axis of inertia the gravitational signal frequency would be exactly two times the rotational frequency of the star. It is possible, however, that this assumption is wrong. This is why search algorithms able to take into account a possible small mismatch between the gravitational waves frequency and the frequency inferred from electromagnetic observations have been developed. In this paper we present an improved pipeline to perform such narrow-band searches for continuous gravitational waves from neutron stars, about three orders of magnitude faster than previous implementations. The algorithm that we have developed is based on the {\it 5-vectors} framework and is able to perform a fully coherent search over a frequency band of width O\mathcal{O}(Hertz) and for hundreds of spin-down values running a few hours on a standard workstation. This new algorithm opens the possibility of long coherence time searches for objects which rotational parameters are highly uncertain.Comment: 19 pages, 8 figures, 6 tables, submitted to CQ

    A new data analysis framework for the search of continuous gravitational wave signals

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    Continuous gravitational wave signals, like those expected by asymmetric spinning neutron stars, are among the most promising targets for LIGO and Virgo detectors. The development of fast and robust data analysis methods is crucial to increase the chances of a detection. We have developed a new and flexible general data analysis framework for the search of this kind of signals, which allows to reduce the computational cost of the analysis by about two orders of magnitude with respect to current procedures. This can correspond, at fixed computing cost, to a sensitivity gain of up to 10%-20%, depending on the search parameter space. Some possible applications are discussed, with a particular focus on a directed search for sources in the Galactic center. Validation through the injection of artificial signals in the data of Advanced LIGO first observational science run is also shown.Comment: 21 pages, 8 figure

    Fosamprenavir treatment in a highly active antiretroviral therapy schedule induces a HCV-RNA decrease and a Th1 network boost in HIV/HCV-coinfected patients

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    AbstractHIV/HCV co-infected naïve patients (four females and six males) were evaluated for their response to the following treatment schedule: [(AZT 300 mg + 3TC 300 mg twice daily) + (fosamprenavir 700 mg twice daily) + (RTV 100 mg)]. CD3+/CD4+ T cells, interferon-γ (INF-γ) and interleukin-4 (IL-4) HCV-specific response, viral loads and transaminase levels were evaluated at time 0, and after 1, 3 and 6 months of therapy (T0, T1, T3, and T6 respectively). HIV-RNA, HCV-RNA and transaminases decreased at T1 and T3 compared with T0 (Mann–Whitney p <0.001, p <0.01 and p <0.01, respectively). At all time points, CD4+ and HCV-specific INF-γ responses were higher (p <0.001; p <0.001), and IL-4 lower (p <0.01) after treatment. At T6, HCV-RNA was only negative in four out of ten patients whereas all had normal transaminase levels. These findings indicate that HAART treatment including fosamprenavir is able to activate a Th1 network in HIV/HCV co-infected patients. Moreover, these results, to be confirmed by larger cohort follow-up studies, suggest that this protease inhibitor could have potential implications for the treatment of chronic hepatitis C in HIV–positive patients
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