673 research outputs found

    Pseudo-dynamic tests on two buildings retrofitted with damped braces

    Get PDF
    Seismic tests have been conducted on two 3-storey buildings protected with fluid-viscous spring damper devices. One of the buildings was a reinforced concrete frame with clay elements in the slabs, while the other one was a steel frame with steel/concrete composite slabs. The spring dampers were installed through K bracing in between the floors. The tests were performed by means of the pseudodynamic method on full-size specimens and by implementing a specific compensation strategy for the strain-rate effects at the devices. The tests results allowed to compare the behaviour of the unprotected buildings with several protected configurations showing the benefits of the application of the devices and the characteristics of their behaviour

    Pseudo-dynamic tests on two buildings retrofitted with damped braces

    Get PDF

    Magnetic field hourly averages from the Rome-GSFC experiment aboard Helios 1 and Helio 2

    Get PDF
    Plots of all the hourly averages computed from the solar magnetic field measurements obtained during the mission are given separately for Helios 1 and Helios 2. The magnitude and the direction of the averaged field are plotted versus the number of solar rotations as seen from Helios, counted from launch

    Dynamic validation of the Planck/LFI thermal model

    Get PDF
    The Low Frequency Instrument (LFI) is an array of cryogenically cooled radiometers on board the Planck satellite, designed to measure the temperature and polarization anisotropies of the cosmic microwave backgrond (CMB) at 30, 44 and 70 GHz. The thermal requirements of the LFI, and in particular the stringent limits to acceptable thermal fluctuations in the 20 K focal plane, are a critical element to achieve the instrument scientific performance. Thermal tests were carried out as part of the on-ground calibration campaign at various stages of instrument integration. In this paper we describe the results and analysis of the tests on the LFI flight model (FM) performed at Thales Laboratories in Milan (Italy) during 2006, with the purpose of experimentally sampling the thermal transfer functions and consequently validating the numerical thermal model describing the dynamic response of the LFI focal plane. This model has been used extensively to assess the ability of LFI to achieve its scientific goals: its validation is therefore extremely important in the context of the Planck mission. Our analysis shows that the measured thermal properties of the instrument show a thermal damping level better than predicted, therefore further reducing the expected systematic effect induced in the LFI maps. We then propose an explanation of the increased damping in terms of non-ideal thermal contacts.Comment: Planck LFI technical papers published by JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/1748-022

    Effect of Fourier filters in removing periodic systematic effects from CMB data

    Full text link
    We consider the application of high-pass Fourier filters to remove periodic systematic fluctuations from full-sky survey CMB datasets. We compare the filter performance with destriping codes commonly used to remove the effect of residual 1/f noise from timelines. As a realistic working case, we use simulations of the typical Planck scanning strategy and Planck Low Frequency Instrument noise performance, with spurious periodic fluctuations that mimic a typical thermal disturbance. We show that the application of Fourier high-pass filters in chunks always requires subsequent normalisation of induced offsets by means of destriping. For a complex signal containing all the astrophysical and instrumental components, the result obtained by applying filter and destriping in series is comparable to the result obtained by destriping only, which makes the usefulness of Fourier filters questionable for removing this kind of effects.Comment: 10 pages, 8 figures, published in Astronomy & Astrophysic

    Another step toward DNA selective targeting: NiII and CuII complexes of a Schiff base ligand able to bind gene promoter G-quadruplexes

    Get PDF
    DNA G-rich sequences are able to form four-stranded structures organized in stacked guanine tetrads. These structures, called G-quadruplexes, were found to have an important role in the regulation of oncogenes expression and became, for such a reason, appealing targets for anticancer drugs. Aiming at finding selective G-quadruplex binders, we have designed, synthesized and characterized a new water soluble Salen-like Schiff base ligand and its NiII and CuII metal complexes. UV-Vis, circular dichroism and FRET measurements indicated that the nickel complex can stabilize oncogene promoter G-quadruplexes with high selectivity, presenting no interactions with duplex DNA at all. The same compound exhibited dose-dependent cytotoxic activity in MCF-7 breast cancer cells when combined with lipofectamine as lipophilic carrier

    Planck-LFI radiometers tuning

    Get PDF
    "This paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst" This paper describes the Planck Low Frequency Instrument tuning activities performed through the ground test campaigns, from Unit to Satellite Levels. Tuning is key to achieve the best possible instrument performance and tuning parameters strongly depend on thermal and electrical conditions. For this reason tuning has been repeated several times during ground tests and it has been repeated in flight before starting nominal operations. The paper discusses the tuning philosophy, the activities and the obtained results, highlighting developments and changes occurred during test campaigns. The paper concludes with an overview of tuning performed during the satellite cryogenic test campaign (Summer 2008) and of the plans for the just started in-flight calibration.Comment: This is an author-created, un-copyedited version of an article accepted for publication in JINST. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at http://dx.doi.org/10.1088/1748-0221/4/12/T12013

    Protein S-nitrosylation: specificity and identification strategies in plants

    Get PDF
    The role of nitric oxide (NO) as a major regulator of plant physiological functions has become increasingly evident. To further improve our understanding of its role, within the last few years plant biologists have begun to embrace the exciting opportunity of investigating protein S-nitrosylation, a major reversible NO-dependent post-translational modification (PTM) targeting specific Cys residues and widely studied in animals. Thanks to the development of dedicated proteomic approaches, in particular the use of the Biotin Switch Technique (BST) combined with mass spectrometry, hundreds of plant protein candidates for S-nitrosylation have been identified. Functional studies focused on specific proteins provided preliminary comprehensive views of how this PTM impacts the structure and function of proteins and, more generally, of how NO might regulate biological plant processes. The aim of this review is to detail the basic principle of protein S-nitrosylation, to provide information on the biochemical and structural features of the S-nitrosylation sites and to describe the proteomic strategies adopted to investigate this PTM in plants. Limits of the current approaches and tomorrow's challenges are also discussed
    corecore