Now showing items 1-20 of 29

    • 119Sn Mössbauer spectroscopy for assessing the local stress and defect state towards the tuning of Ni-Mn-Sn alloys 

      Unzueta, Iraultza; López García, Javier Upna; Sánchez-Alarcos Gómez, Vicente Upna; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna (AIP Publishing, 2017)   Artículo / Artikulua  OpenAccess
      The influence of defects and local stresses on the magnetic properties and martensitic transformation in Ni50Mn35Sn15 is studied at macroscopic and atomic scale levels. We show that both the structural and magnetic properties ...
    • Are urban noise pollution levels decreasing? 

      Arana Burgui, Miguel Upna (Acoustical Society of America, 2010)   Artículo / Artikulua  OpenAccess
      The majority of acoustic impact studies developed over the last 50 years have used a similar acoustic parameter Leq, Ldn but the noise mapping methodology has been very uneven. The selection of the measurement points, ...
    • Aspectos biopsicológicos de la infección por virus inmunodeficiencia humana (VIH) 

      Aparicio Ágreda, María Lourdes Upna; Cuevas Jiménez, Carlos Pablo (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2006)   Artículo / Artikulua  OpenAccess
      El objetivo de este artículo es ofrecer una comprensión global de la infección por VIH. Si bien es un proceso inicialmente asintomático, el avance de la infección produce consecuencias a nivel de funcionamiento, en gran ...
    • Changes in the crystalline degree in neutron irradiated EPDM viewed through infrared spectroscopy and inelastic neutron scattering 

      Lambri, Osvaldo Agustín; Giordano, E. D.; Bonifacich, Federico Guillermo; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna (Rede Latino-Americana de Materiais, 2018)   Artículo / Artikulua  OpenAccess
      The changes in the degree of crystallinity in commercial Ethylene Propylene Diene rubber-type M (EPDM) irradiated with neutrons at different doses has been studied by means of inelastic neutron scattering and infrared ...
    • A comprehensive analysis of the absorption spectrum of conducting ferromagnetic wires 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gómez Polo, Cristina Upna; Labrador Otamendi, Alberto; Pérez de Landazábal Berganzo, José Ignacio Upna; Gonzalo García, Ramón Upna (IEEE, 2012)   Artículo / Artikulua  OpenAccess
      A detailed analysis of the absorption spectrum of conductive ferromagnetic wires is presented. The absorption spectrum is computed from the solution to the scattering problem, and circuit models are formulated to clarify ...
    • CSigma graphs: a new approach for plasma characterization in laser-induced breakdown spectroscopy 

      Aragón Garbizu, Carlos Upna; Aguilera Andoaga, José Antonio Upna (Elsevier, 2014)   Artículo / Artikulua  OpenAccess
      A generalization of curves of growth called CSigma (Cσ) graphs, which allows including several lines of various elements in the same ionization state at different concentrations, is proposed for laser-induced breakdown ...
    • Entropy change caused by martensitic transformations of ferromagnetic shape memory alloys 

      L'vov, Victor A.; Cesari, Eduard; Kosogor, Anna; Torrens Serra, Joan; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      In this paper, our most recent findings on the influence of magnetic order on the main transformational caloric and elastic properties of shape memory alloys (SMAs) are reviewed. It is argued that ferromagnetic order has ...
    • Evolution of magnetic response as a function of annealing temperature in Fe-based alloys 

      Gargicevich, Damián; Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna (Rede Latino-Americana de Materiais, 2018)   Artículo / Artikulua  OpenAccess
      The magnetic response, coercive force and magnetic induction, in Fe-10at.% Si, Fe-6at.% Al-9at.% Si and Fe-4at.% Al-8at.% Ge alloys as a function of the annealing temperature was determined and correlated to the microstructural ...
    • Experimental Stark widths and shifts of Cr II spectral lines 

      Aguilera Andoaga, José Antonio Upna; Aragón Garbizu, Carlos Upna; Manrique Rosel, Javier (Oxford University Press, 2013)   Artículo / Artikulua  OpenAccess
      Stark widths and shifts of Cr II lines with wavelengths in the range 2000–3500 Å have been determined by laser-induced breakdown spectroscopy. The spectra have been measured at different instants of the plasma ...
    • A field induced ferromagnetic-like transition below 2.8 K in Li2CuO2: An experimental and theoretical study 

      Ortega Hertogs, Ricardo Upna; Jensen, P. J.; Rao, K. V.; Sapiña, F.; Beltrán, D.; Iqbal, Z.; Cooley, J. C.; Smith, J. L. (AIP Publishing, 1998)   Artículo / Artikulua  OpenAccess
      The low temperature magnetic properties of the Li2CuO2 compound have been investigated by means of superconducting quantum interference device magnetometry. We find in addition to an antiferromagnetic phase below 9.5 K a ...
    • Generating and measuring the anisotropic elastic behaviour of Co thin films with oriented surface nano-strings on micro-cantilevers 

      Madurga Pérez, Vicente Upna; Vergara Platero, José Upna; Favieres Ruiz, Cristina Upna (Springer, 2011)   Artículo / Artikulua  OpenAccess
      In this research, the elastic behaviour of two Co thin films simultaneously deposited in an off-normal angle method was studied. Towards this end, two Si micro-cantilevers were simultaneously coated using pulsed laser ...
    • Giant direct and inverse magnetocaloric effect linked to the same forward martensitic transformation 

      Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Sánchez-Alarcos Gómez, Vicente Upna; Beato López, Juan Jesús Upna; Rodríguez Velamazán, José Alberto; Sánchez Marcos, J.; Gómez Polo, Cristina Upna; Cesari, Eduard (Springer Nature, 2017)   Artículo / Artikulua  OpenAccess
      Metamagnetic shape memory alloys have aroused considerable attraction as potential magnetic refrigerants due to the large inverse magnetocaloric effect associated to the magnetic-field-induction of a reverse martensitic ...
    • Influence of defects on the irreversible phase transition in the Fe-Pd doped with Co and Mn 

      Bonifacich, Federico Guillermo; Lambri, Osvaldo Agustín; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Sánchez-Alarcos Gómez, Vicente Upna (Rede Latino-Americana de Materiais, 2018)   Artículo / Artikulua  OpenAccess
      The appearance of BCT martensite in Fe-Pd-based ferromagnetic shape memory alloys, which develops at lower temperatures than the thermoelastic martensitic transition, deteriorates the shape memory properties. In a previous ...
    • Long-range atomic order and entropy change at the martensitic transformation in a Ni-Mn-In-Co metamagnetic shape memory alloy 

      Sánchez-Alarcos Gómez, Vicente Upna; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Cesari, Eduard; Rodríguez Velamazán, José Alberto (MDPI, 2014)   Artículo / Artikulua  OpenAccess
      The influence of the atomic order on the martensitic transformation entropy change has been studied in a Ni-Mn-In-Co metamagnetic shape memory alloy through the evolution of the transformation temperatures under high-temperature ...
    • Loss of ductility due to the decarburation and Mn depletion of a coarse-grained TWIP steel 

      Cuevas Jiménez, Fernando de las Upna; Gil Sevillano, Javier (Consejo Superior de Investigaciones Científicas (CSIC), 2017)   Artículo / Artikulua  OpenAccess
      Se ha observado una clara transición de la ductilidad a tracción con el tamaño de grano D del orden 15 μm - 20 μm (1,50 μm ≤ D < 50 μm) en un acero TWIP, 22% de Mn, 0,6% de C (% en masa). Este comportamiento es una combinación ...
    • Low field magnetic and thermal hysteresis in antiferromagnetic dysprosium 

      Liubimova, Iuliia; Corró Moyá, Miguel; Torrens Serra, Joan; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Kustov, Sergey (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Magnetic and thermal hysteresis (difference in magnetic properties on cooling and heating) have been studied in polycrystalline Dy (dysprosium) between 80 and 250 K using measurements of the reversible Villari effect and ...
    • Magnetic anisotropy in isotropic and nanopatterned strongly exchange-coupled nanolayers 

      Vergara Platero, José Upna; Favieres Ruiz, Cristina Upna; Madurga Pérez, Vicente Upna (Springer, 2012)   Artículo / Artikulua  OpenAccess
      In this study, the fabrication of magnetic multilayers with a controlled value of the in-plane uniaxial magnetic anisotropy field in the range of 12 to 72 kA/m was achieved. This fabrication was accomplished by the ...
    • Magnetic transition in nanocrystalline soft magnetic alloys analyzed via ac inductive techniques 

      Gómez Polo, Cristina Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Vázquez, M.; Hernando, A. (American Physical Society, 2004)   Artículo / Artikulua  OpenAccess
      The magnetic transition in a FeSiBCuNb nanocrystalline alloy, associated with the decoupling of ferromagnetic crystallites around the Curie point of the residual amorphous matrix, is analyzed in this work through the ...
    • Magnetocaloric effect enhancement driven by intrinsic defects in a Ni45Co5Mn35Sn15 alloy 

      Sánchez-Alarcos Gómez, Vicente Upna; López García, Javier Upna; Unzueta, Iraultza; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Beato López, Juan Jesús Upna; García, José Ángel; Plazaola, Fernando; Rodríguez Velamazán, José Alberto (Elsevier, 2019)   Artículo / Artikulua
      The influence of mechanically-induced defects on the magnetostructural properties is analyzed in a Ni-Co-Mn-Sn alloy subjected to soft milling and subsequent annealing treatments. It is found that, opposite to what occurs ...
    • Method for measurement of transition probabilities by laser-induced breakdown spectroscopy based on CSigma graphs. Application to Ca II spectral lines 

      Aguilera Andoaga, José Antonio Upna; Aragón Garbizu, Carlos Upna; Manrique Rosel, Javier (Elsevier, 2015)   Artículo / Artikulua  OpenAccess
      We propose a method for determination of transition probabilities by laser-induced breakdown spectroscopy that avoids the error due to self-absorption. The method relies on CSigma graphs, a generalization of curves of ...