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Browsing by Issue Date, starting with "2018-05-17"

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  • Design Challenges of a Maritime Multipurpose Unmanned Vehicle
    Publication . Lopes, Vasco Pereira; Silva, Paulo Alexandre Marques Pires da; Moreira, Miguel
    Military Navies have several missions in which due to their complex, dangerous, or disaster scenarios, unmanned vehicles are suitable to perform the necessary tasks. Besides other issues it is a current subject of research the trade-off between using many mission oriented unmanned vehicles or the use of less number of more robust and versatile multimission vehicles. Challenged by the technological advances achieved in mobile robotics and unmanned vehicles, and the need to develop in house know-how, this project aimed to put into practice the development of a concept design of a multimission unmanned surface vehicle, that can operate individually or cooperate with other systems whose development will be done in parallel on other projects. This unmanned vehicle, designated Unmanned Surface Vehicle for the Portuguese Navy - USV – PoN is part of project based oriented learning strategy in development in the Portuguese Naval Academy. It poses particular challenges related to the broad spectrum of the concept of operations, such as mine warfare operations, port surveillance and protection operations, search and rescue operations, hydrographic data collection operations. All of these operations demand different and challenging missions and tasks, to which the concept design of the USV-PoN will answer in terms of feasibility studies and possible configurations. The purpose of this work is to address the challenges that the concept of operations and corresponding technical specifications put into the design of the USV-PoN and show how to overcome them making the study and analysis necessary for the production of a prototype based on the concept design. Out of the scope of this work were aspects related to sensor development and integration as well as the command and control of the vehicle.
    2018-05-17Conference object Open access Show more
  • 2018-05-17Master thesis Open access Show more
  • Measurement of prompt $D^0$ meson azimuthal anisotropy in Pb-Pb collisions at $\sqrt{{s}_{NN}}$ = 5.02 TeV
    Publication . CMS collaboration (2239 authors); Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale
    The prompt D0 meson azimuthal anisotropy coefficients, v2 and v3, are measured at midrapidity (|y|<1.0) in Pb-Pb collisions at a center-of-mass energy sNN=5.02  TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (pT) range of 1 to 40  GeV/c, for central and midcentral collisions. The v2 coefficient is found to be positive throughout the pT range studied. The first measurement of the prompt D0 meson v3 coefficient is performed, and values up to 0.07 are observed for pT around 4  GeV/c. Compared to measurements of charged particles, a similar pT dependence, but smaller magnitude for pT<6  GeV/c, is found for prompt D0 meson v2 and v3 coefficients. The results are consistent with the presence of collective motion of charm quarks at low pT and a path length dependence of charm quark energy loss at high pT, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.
    2018-05-17Journal article Open access Show more
  • 2018-05-17Master thesis Open access Show more