@Article{OliveiraMaMaAgFrPi:2010:DaAnMo,
               author = "Oliveira, F. G. and Marinho Jr., R. M. and Magalh{\~a}es, N. S. 
                         and Aguiar, O. D. and Frajuca, C. and Pires, R.",
          affiliation = "Instituto Tecnol{\'o}gico de Aeron{\'a}utica, Departamento de 
                         F{\'{\i}}sica, 12.228-900 S{\~a}o Jos{\'e} dos Campos, SP, 
                         Brazil and Instituto Tecnol{\'o}gico de Aeron{\'a}utica, 
                         Departamento de F{\'{\i}}sica, 12.228-900 S{\~a}o Jos{\'e} dos 
                         Campos, SP, Brazil and Universidade Federal de S{\~a}o Paulo, 
                         Prof. Artur Riedel, 275, Diadema, SP 09972-270, Brazil and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)} and Instituto 
                         Federal de S{\~a}o Paulo, Pedro Vicente 625, SP, Brazil and 
                         Instituto Federal de S{\~a}o Paulo, Pedro Vicente 625, SP, 
                         Brazil",
                title = "Data Analysis of Monochromatic Signals from ALLEGRO GW Detector",
              journal = "Nature",
                 year = "2010",
               volume = "199",
               number = "1",
                pages = "353--356",
                month = "Feb.",
                 note = "{Proceedings of the International Workshop Light Cone 2009 
                         (LC2009): Relativistic Hadronic and Particle Physics}",
             abstract = "This research work brings about additional contribution to 
                         validate the ultrasound scattering technique as a nonintrusive 
                         probe in the Fourier space for measurements performed in unsteady 
                         flows. In particular, this work reports experimental evidence of 
                         scattering from a turbulent thermal plume utilized as a testing 
                         flow. This technique is based upon the scattering of an ultrasound 
                         wave hitting and interacting with an unstable flow. The coupling 
                         among the acoustic mode with vorticity and entropy modes is 
                         derived from nonlinear terms of NavierStokes and energy equations. 
                         Scattering mechanism occurs when characteristic length scales of 
                         flows are comparable with wavelength of sound. Thus, it is 
                         possible to probe the flow at different length scales by changing 
                         the incoming frequency. The results allow verifying some 
                         theoretical predictions, such as the existence of a nonscattering 
                         angle. It was also observed, that both the phase and the Doppler 
                         shift of the Fourier's signal are linear, respectively, with 
                         respect to the time and the frequency of the incident wave. The 
                         Doppler shift allowed us to determine the advection velocity and 
                         has proved to be sensitive to the direction of the wave vector, to 
                         the scattering angle and also, we show that it is possible to have 
                         both positive and negative angles. The advection velocity 
                         increases with temperature and its values are coherent with those 
                         obtained with traditional techniques. Broadening and Doppler shift 
                         of the scattering signal allowed us to define the turbulence 
                         intensity, whose values are in agreement with those found in 
                         thermal plumes, where well-known techniques are currently used. 
                         This study has shown that the turbulence intensity increases 
                         weakly with temperature, nevertheless it seems more sensitive to 
                         the size of the structure under observation.",
                  doi = "10.1016/j.nuclphysbps.2010.02.059",
                  url = "http://dx.doi.org/10.1016/j.nuclphysbps.2010.02.059",
                 issn = "0028-0836",
           targetfile = "magalhaes.pdf",
        urlaccessdate = "06 maio 2024"
}