Now showing items 17-29 of 29

    • 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 ...
    • People exposed to traffic noise in european agglomerations from noise maps: a critical review 

      Arana Burgui, Miguel Upna; San Martín Murugarren, Ricardo Upna; Salinas Hilburg, Juan Carlos (De Gruyter, 2014)   Artículo / Artikulua  OpenAccess
      Two of the main objectives of the European Directive on environmental noise are, firstly, to unify acoustic indices for assessing environmental noise and, secondly, to standardize assessment methodologies. The ultimate ...
    • Simple fabrication of ultrahigh aspect ratio nanostructures for enhanced antireflectivity 

      Domínguez Fernández, Sagrario; Cornago Santos, Ignacio; Bravo Larrea, Javier Upna; Pérez Conde, Jesús Upna; Choi, Hyungryul J.; Kim, Jeong-Gil; Barbastathis, George (American Vacuum Society, 2014)   Artículo / Artikulua  OpenAccess
      In this work, the authors present a novel fabrication process to create periodic nanostructures with aspect ratio as high as 9.6. These nanostructures reduce spectral reflectance of silicon to less than 4% over the broad ...
    • Strategic noise map of a major road carried out with two environmental prediction software packages 

      Arana Burgui, Miguel Upna; San Martín Murugarren, Ricardo Upna; San Martín Erviti, María Luisa Upna; Aramendía Santamaría, Emilio Upna (Springer Netherlands, 2010)   Artículo / Artikulua  OpenAccess
      The main objective of this study is to analyze the differences found in the results of noise mapping using two of the most popular software techniques for the prediction of environmental noise. The location selected ...
    • Strong angular dependence of resonant states in 2D dielectric cylinder rings 

      Andueza Unanua, Ángel María Upna; Pérez Conde, Jesús Upna; Sevilla Moróder, Joaquín Upna (AIP Publishing, 2018)   Artículo / Artikulua  OpenAccess
      We investigate collective resonators made of dielectric cylinders assembled as two-dimensional regular octagons and decagons. These structures exhibit collective resonance states that change their intensity with the incident ...
    • Structurally oriented nano-sheets in Co thin films: changing their anisotropic physical properties by thermally-induced relaxation 

      Vergara Platero, José Upna; Favieres Ruiz, Cristina Upna; Magén, César; Teresa, José María de; Ibarra, Manuel Ricardo; Madurga Pérez, Vicente Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      We show how nanocrystalline Co films formed by separated oblique nano-sheets display anisotropy in their resistivity, magnetization process, surface nano-morphology and optical transmission. After performing a heat treatment ...
    • Study of optical fiber sensors for cryogenic temperature measurements 

      Miguel Soto, Verónica de Upna; Leandro González, Daniel Upna; López Aldaba, Aitor Upna; Beato López, Juan Jesús Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg ...
    • Study of the martensitic transition in Ni-Mn-Sn-Ti ferromagnetic shape memory alloys 

      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
      In the present work, mechanical spectroscopy measurements as a function of temperature and strain have been performed in (at.%) Ni50Mn37Sn13-xTix (x=0, 0.5 and 2) ferromagnetic shape memory alloys in order both to study ...
    • Thermal degradation of type I collagen from bones 

      Lambri, M. L.; Giordano, E. D.; Bozzano, P. B.; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna (Tech Science Press, 2016)   Artículo / Artikulua  OpenAccess
      The denaturation processes of collagen in the temperature range between 450 K and 670 K are revealed through studies performed on cow rib bones by means of mechanical spectroscopy, differential scanning calorimetry, ...
    • Uncertainties caused by source directivity in room-acoustic investigations 

      San Martín Murugarren, Ricardo Upna; Arana Burgui, Miguel Upna (Acoustical Society of America (ASA), 2008)   Artículo / Artikulua  OpenAccess
      Although deviations in the measurement of acoustic parameters should be lower than the subjectively perceivable change in the corresponding parameter measured, this study reflects that directionality of sound sources could ...