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Haimov H.,Canal de Experiencias Hidrodinamicas de El Pardo CEHIPAR | Gallego V.,Instituto Tecnologico La Maranosa ITM | Molinelli E.,Canal de Experiencias Hidrodinamicas de El Pardo CEHIPAR | Trujillo B.,Instituto Tecnologico La Maranosa ITM
Ocean Engineering | Year: 2015

The study describes the implementation of experimental procedure for measuring the hydrodynamic noise generated by model scale marine propellers in atmospheric towing tank. The study is limited to non-cavitating conditions of the propeller as the experimental tank is at atmospheric pressure. The towing carriage and conditions have not been altered admitting the existence of considerable background noise. The feasibility analysis included experimental and theoretical study of the background noise at the operating conditions. Some considerations about the uncertainty of the results are also presented. The experimental equipment, set up and procedure for measuring the acoustic pressure around model ship propeller and/or hull is also described. Simultaneous measurements with various differently positioned hydrophones at multiple hydrodynamic conditions permitted to evaluate the background and propeller/hull generated acoustic field at a range of frequencies. An appropriate treatment of the recorded time series characterised the background disturbances and permitted to obtain net results with sufficient signal to noise ratio, mostly from narrowband spectral analysis. Results for the impact of the hull presence on propeller acoustic field are presented and discussed. The extrapolated results are compared informatively with full scale measurements. The research presented in this paper is a result of the Collaboration agreement on underwater acoustics between CEHIPAR and ITM and is partially funded by the European Commission project AQUO (Achieve Quieter Oceans by Shipping Noise Footprint Reduction), Seventh Framework Programme, Grant number 314227, FP7-SST-2012.1.1-1. © 2015 Elsevier Ltd.

Torquemada M.C.,Instituto Tecnologico la Maranosa ITM | Villamayor V.,Instituto Tecnologico la Maranosa ITM | Gomez L.J.,Instituto Tecnologico la Maranosa ITM | Vergara G.,Instituto Tecnologico la Maranosa ITM | And 13 more authors.
Sensors and Actuators, A: Physical | Year: 2013

We report on the manufacture of a dual band uncooled infrared detector of lead selenide for smart detection of IR emitters. The first advanced bicolor PbSe sensor with its spectral response modified by design for our purpose has been developed by means of the monolithical integration of two high-pass interference filters and polycrystalline PbSe sensors. Wavelength cut-on of the filters was 3.7 and 4.3 μm. Room temperature detectivities of unfiltered lead selenide yield values of D*pk (3.6 μm, 330 Hz, 1 Hz) ∼ 10 9 cm Hz1/2/W. Considering the excellent properties of this MWIR sensor, the possibility of enhancing it with a selected spectral response opens its use to a wide range of applications. © 2013 Elsevier B.V. All rights reserved.

Sierra C.,Instituto Tecnologico la Maranosa ITM | Torquemada M.C.,Instituto Tecnologico la Maranosa ITM | Vergara G.,Instituto Tecnologico la Maranosa ITM | Rodrigo M.T.,Instituto Tecnologico la Maranosa ITM | And 10 more authors.
Sensors and Actuators, B: Chemical | Year: 2014

PbSe detectors are photoconductors with optimum response in the medium-wavelength infrared region. PbSe detectors provide fast response and high sensibility at room temperature, are rugged and show resistance to environmental conditions, providing low cost detecting devices. These properties make this detector a good candidate for a wide range of applications, including the field of gas detection. Gas detection technologies may require detection capabilities and operational performance. In order to have sensors with optimum detection of chemical compounds in vapour phase, the selectivity of PbSe has been improved by means of advanced interference filters, to allow the detection of low concentrations of chemicals species. To give the detectors an added value, PbSe detectors have been monolithically integrated with the selected interference filters. Here we report on the results obtained in order to process PbSe detectors with the spectral response modified by design. The requirements for gas detection are tight because they involve high transmittance for the pass band, broad rejection range and low transmittance value out of band. Filters designed and produced for our purpose were double Fabry-Perot cavity based interference filters. First trials with gases show good sensitivity. © 2013 Elsevier B.V. All rights reserved.

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