1,891 research outputs found

    Scalar GW detection with a hollow spherical antenna

    Get PDF
    We study the response and cross sections for the absorption of GW energy in a Jordan-Brans-Dicke theory by a resonant mass detector shaped as a hollow sphere.Comment: latex file, 9 page

    FMCW Radar Phase-Processing for Automotive Application

    Get PDF
    An unmanned high-speed vehicle requires a high resolution control unit to decide whether the vehicle should break or steer. This paper describes the utilization of a Frequency Modulated Continous Wave (FMCW) radar to detect the distance and angular position of the target relative to the moving vehicle. These informations are calculated from some numbers of data obtained from a radar system that is mounted on the moving vehicle. To obtain a high angular resolution, a phase-processing approach is introduced by extracting the constant phase information from the radar FMCW beat signal. It is found that a very high angular resolution can be obtained by processing the phase information, independent from the change of relative velocity between the radar and the target. However, this method requires a very stable radar system with high phase resolution and accuracy

    Gravitational-Wave Stochastic Background Detection with Resonant-Mass Detectors

    Get PDF
    In this paper we discuss how the standard optimal Wiener filter theory can be applied, within a linear approximation, to the detection of an isotropic stochastic gravitational-wave background with two or more detectors. We apply then the method to the AURIGA-NAUTILUS pair of ultra low temperature bar detectors, near to operate in coincidence in Italy, obtaining an estimate for the sensitivity to the background spectral density of $\simeq 10^{-49}\ Hz^{-1},thatconvertstoanenergydensityperunitlogarithmicfrequencyof, that converts to an energy density per unit logarithmic frequency of \simeq 8\times10^{-5}\times\rho_cwith with \rho_c\simeq1.9 \times 10^{-26}\ kg/m^3theclosuredensityoftheUniverse.WealsoshowthatbyaddingtheVIRGOinterferometricdetectorunderconstructioninItalytothearray,andbyproperlyre−orientingthedetectors,onecanreachasensitivityof the closure density of the Universe. We also show that by adding the VIRGO interferometric detector under construction in Italy to the array, and by properly re- orienting the detectors, one can reach a sensitivity of \simeq 6 \times10^{-5}\times\rho_c.WethencalculatethatthepairformedbyVIRGOandonelargemasssphericaldetectorproperlylocatedinoneofthenearbyavailablesitesinItalycanreahasensitivityof. We then calculate that the pair formed by VIRGO and one large mass spherical detector properly located in one of the nearby available sites in Italy can reah a sensitivity of \simeq 2\times10^{-5}\times \rho_cwhileapairofsuchsphericaldetectorsatthesamesitesofAURIGAandNAUTILUScanachievesensitivitiesof while a pair of such spherical detectors at the same sites of AURIGA and NAUTILUS can achieve sensitivities of \simeq 2 \times10^{-6}\rho_c$.Comment: 32 pages, postscript file, also available at http://axln01.lnl.infn.it/reports/stoch.htm

    In vitro assessment of tick-borne encephalitis vaccine:Suitable human cell platforms and potential biomarkers

    Get PDF
    Tick-borne encephalitis (TBE) virus causes a severe disease that can lead to permanent neurological complications. The whole inactivated TBE vaccine is highly effective, as proven by high seroconversion rates and near eradication of the disease in countries where vaccination programs have been implemented. TBE vaccine potency testing currently requires the use of in vivo methods that present issues of reproducibility as well as animal discomfort. As an alternative, public and private entities are currently exploring a batch-to-batch consistency approach which would demonstrate conformity of a newly produced vaccine batch with a batch with proven in vivo efficacy with respect to a range of in vitro measurable quality parameters. For the identification of a suitable cellular platform to be used in a panel of in vitro batch-to-batch assessments for the TBE vaccine, we exposed human cell-based systems, both of primary origin and cell line-derived, to vaccine formulations of high and low quality. Following stimulation, cell responses were evaluated by assessing the expression of selected genes by qPCR. Our findings show that the expression of interferon-stimulated genes differed after treatment with non-adjuvanted vaccine batches of different quality in peripheral blood mononuclear cells (PBMCs) and in monocyte-derived dendritic cells, but not in monocyte-free PBMC suspensions nor in cell line-derived immune cells. These results indicate suitable platforms and potential biomarkers for a cell-based assay that, together with other immunochemical analyses, could serve for batch-to-batch assessment of the TBE vaccine, reducing (and eventually replacing) in vivo methods for potency testing

    Wideband dual sphere detector of gravitational waves

    Get PDF
    We present the concept of a sensitive AND broadband resonant mass gravitational wave detector. A massive sphere is suspended inside a second hollow one. Short, high-finesse Fabry-Perot optical cavities read out the differential displacements of the two spheres as their quadrupole modes are excited. At cryogenic temperatures one approaches the Standard Quantum Limit for broadband operation with reasonable choices for the cavity finesses and the intracavity light power. A molybdenum detector of overall size of 2 m, would reach spectral strain sensitivities of 2x10^-23/Sqrt{Hz} between 1000 Hz and 3000 Hz.Comment: 4 pages, 3 figures. Changed content. To appear in Phys. Rev. Let

    Demand Side Management analysis of a commercial Water Loop Heat Pump system

    Get PDF
    Demand side management (DSM) can be defined as a set of measures adopted to modify customers\u2019 energy demand with the aim of improving the efficiency of the overall energy system. Indeed, DSM strategies can be used to reduce customers\u2019 demand at peak times, reduce energy consumption seasonally/yearly, change the timing of end-use consumption from high to low-cost periods, and increase consumption during off-peak periods. DSM strategies can be implemented by using the energy flexibility available in the final users\u2019 applications, e.g. the thermal inertia of the building mass, the presence of additional energy storage systems enabling load shaping or the use of control systems to turn on/off end-users\u2019 devices when required. Being intensive energy consumers because of a high electric energy demand (mainly for refrigeration, which accounts for about 40 % of the yearly energy consumption), supermarkets are ideal candidates for energy use optimizations obtained through a DSM approach. This work shows the results of a DSM analysis carried out for a refrigeration and HVAC plant in a supermarket coupled with a Water Loop Heat Pump (WLHP) system. The water loop is used as a heat source/sink for the refrigeration unit supplying the cooling capacity required by food preservation and for several heat pumps that provide heating/cooling inside the supermarket building. The system is modelled in TRNSYS and the role of the water loop and its thermal inertia to provide energy flexibility is investigated. The system design and control strategy are modified in order to reduce the electricity costs in presence of demand response programs based on real-time price mechanisms

    Testing Theories of Gravity with a Spherical Gravitational Wave Detector

    Get PDF
    We consider the possibility of discriminating different theories of gravity using a recently proposed gravitational wave detector of spherical shape. We argue that the spin content of different theories can be extracted relating the measurements of the excited spheroidal vibrational eigenmodes to the Newman-Penrose parameters. The sphere toroidal modes cannot be excited by any metric GW and can be thus used as a veto.Comment: latex file, 16 pages, 1 figur

    On the Detection of a Scalar Stochastic Background of Gravitational Waves

    Get PDF
    In the near future we will witness the coming to a full operational regime of laser interferometers and resonant mass detectors of spherical shape. In this work we study the sensitivity of pairs of such gravitational wave detectors to a scalar stochastic background of gravitational waves. Our computations are carried out both for minimal and non minimal coupling of the scalar fields.Comment: 25 pages, 3 figure
    • …
    corecore