Exploració per autor "Roa Rovira, Joan Josep"Més informacióMés informació

Ara es mostren els items 126-145 de 185

    • Nano-mechanical properties of silver-welded YBCO bulks 

      Roa Rovira, Joan Josep; Bartolomé, E.; Bozzo, Bernat; Capdevila, X.G.; Granados García, Javier A.J.; Segarra, M. (2010-02-09)
      Article
      Accés obert
      The mechanical properties of melt-textured YBCO bulk boundaries are a topic of special interest especially in the manufacturing of superconductor devices for engineering applications. Instrumented indentation technique ...

    • Nanoindentation and fracture toughness of nanostructured zirconia/multi-walled carbon nanotube composites 

      Melk, Latifa; Roa Rovira, Joan Josep; García Marro, Fernando; Antti, Marta-Lena; Milsom, Ben; Reece, Michel; Anglada Gomila, Marcos Juan (2015-03-01)
      Article
      Accés obert
      Multi-walled carbon nanotubes (MWCNTs)/3 mol% yttria-doped tetragonal zirconia (3Y-TZP) composites were produced using spark plasma sintering (SPS) with MWCNT content ranging within 0-2 wt%. In the present paper, it was ...

    • Nanoindentation and scratch resistance of multilayered TiO2-SiO2 coatings with different nanocolumnar structures deposited by PV-OAD 

      Roa Rovira, Joan Josep; Rico, V.; Oliva-Ramírez, M; Gonzalez-Elipe, A.R.; Jiménez Piqué, Emilio (2016)
      Article
      Accés obert
      This paper presents a study of the mechanical properties and an evaluation of damage mechanisms of nanocolumnar TiO2-SiO2 multilayer coatings prepared by physical vapour oblique angle deposition at different configurations ...

    • Nanoindentation of advanced ceramics. applications to ZrO2 materials 

      Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Anglada Gomila, Marcos Juan (John Willey & Sons, 2015)
      Capítol de llibre
      Accés restringit per política de l'editorial
      This chapter describes commonly used methods of analyzing and interpreting hardness, elastic modulus and indentation stress-strain curve for bulk and coating ceramics. Examples of different materials, but specially zirconia ...

    • Nanoindentation of Bridgman YBCO samples 

      Roa Rovira, Joan Josep; Konstantopoulou, Dimitra; Jiménez Piqué, Emilio; Martín, V.; Segarra, M.; Pastor, J.Y. (2012-04)
      Article
      Accés restringit per política de l'editorial
      n this study, the mechanical properties of YBa2Cu3O7−x, obtained by the Bridgman technique, were examined using a Berkovich tip indenter on the basal plane (0 0 1). Intrinsic hardness was measured by nanoindentation tests ...

    • Nanoindentation of multilayered epitaxial YBa2Cu 3O7-d thin films and coated conductors 

      Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Puig Molina, Teresa; Obradors i Berenguer, Francesc Xavier; Segarra, M. (2011-02-01)
      Article
      Accés restringit per política de l'editorial
      Nanoindenter tests were carried out on YBa2Cu3O7-δ (YBCO) coatings with different buffer layers, in order to obtain the Hardness (H) tendency, Young's modulus (E), and the fracture mechanism activated during the indentation ...

    • Nanoindentation with spherical tips of single crystals of YBCO textured by the Bridgman technique: Determination of indentation stress-strain curves 

      Roa Rovira, Joan Josep; Jiménez Piqué, Emilio; Capdevila, X.G.; Segarra, M. (2010-04)
      Article
      Accés restringit per política de l'editorial
      The mechanical properties of superconductor ceramics are of interest in the manufacture of superconducting devices. The current trend is to produce smaller devices (using, e.g., thin films), and the correct characterization ...

    • Nanosecond-laser patterning of 3Y-TZP: damage and microstructural changes 

      Roitero, Erica; Lasserre, F.; Roa Rovira, Joan Josep; Anglada Gomila, Marcos Juan; Mücklich, F.; Jiménez Piqué, Emilio (Elsevier, 2017-12)
      Article
      Accés obert
      The aim of this study is to characterize in detail the microstructural changes and collateral damage induced by direct laser patterning on the surface of dental-grade zirconia (3Y-TZP) employing an interference setup with ...

    • Novel mechanical characterization of austenite and ferrite phases within duplex stainless steel 

      Besharatloo, H.; Carpio Garza, Marcel Francisco; Cabrera Marrero, José M.; Mateo García, Antonio Manuel; Fargas Ribas, Gemma; Wheeler, Jeffrey; Roa Rovira, Joan Josep; Llanes Pitarch, Luis Miguel (Multidisciplinary Digital Publishing Institute (MDPI), 2020-10)
      Article
      Accés obert

    • Optimization of the ceramic ink used in Direct Ink Writing through rheological properties characterization of zirconia-based ceramic materials 

      Yarahmadi, Mona; Barcelona, Pol; Fargas Ribas, Gemma; Xuriguera Martin, Elena; Roa Rovira, Joan Josep (2022-02)
      Article
      Accés obert
      Understanding and optimization the rheological properties characterization of zirconia (ZrO2) based ceramics inks is critical for optimizing the production of Direct Ink Writing (DIW) components to achieve complex structures ...

    • Optimization of the sintering thermal treatment and the ceramic ink used in direct ink writing of a-Al2O3: Characterization and catalytic application 

      Álvarez Maté, Ferran; Cifuentes López, Alejandro; Serrano Carreño, M. Isabel; Franco García, María Lourdes; Fargas Ribas, Gemma; Fenollosa i Artés, Felip; Uceda Molera, Roger; Llanes Pitarch, Luis Miguel; Tardivat, C; Llorca Piqué, Jordi; Roa Rovira, Joan Josep (Elsevier, 2022-06-01)
      Article
      Accés restringit per política de l'editorial
      Unlike other engineered ceramic products, alumina (Al2O3) displays interesting mechanical and physical properties, which makes it an ideal candidate for a wide range of uses in different fields and in particular for catalytic ...

    • Overview of surface modification strategies for improving the properties of metastable austenitic stainless steels 

      Rezayat, Mohammad; Karamimoghadam, Mojtaba; Moradi, Mahmoud; Casalino, Giuseppe; Roa Rovira, Joan Josep; Mateo García, Antonio Manuel (Multidisciplinary Digital Publishing Institute (MDPI), 2023-07-14)
      Article
      Accés obert
      Metastable austenitic stainless steels (MASS) are widely used in various industrial applications due to their exceptional compromise between mechanical properties and corrosion resistance. However, the mechanical properties ...

    • Oxidation behavior of maraging 300 alloy exposed to nitrogen/water vapor atmosphere at 500 °C 

      Cerra Flórez, Mauro Andrés; Fargas Ribas, Gemma; Mateo García, Antonio Manuel; Roa Rovira, Joan Josep (Multidisciplinary Digital Publishing Institute (MDPI), 2021-06-24)
      Article
      Accés obert
      Aging heat treatments in maraging steels are fundamental to achieve the excellent mechanical properties required in several industries, i.e., nuclear, automotive, etc. In this research, samples of maraging 300 alloy were ...

    • Oxygenation kinetics of YBCO-TSMG samples using Nanoindentation technique 

      Roa Rovira, Joan Josep; Dias, Fabio T.; Martinez, Monica; Padilla, Josep Antonio; Segarra, M. (Elsevier, 2012-02-14)
      Article
      Accés restringit per política de l'editorial
      Since hardness is a quantitative measure of bulk mechanical properties, it can be used to examine the kinetics of crack propagation inside YBa2Cu3O7−δ (YBCO or Y-123) ceramics. YBCO samples with a tetragonal phase were ...

    • Paramagnetic meissner effect and strong time dependence at high fields in melt-textured high-Tc superconductors 

      Gouvêa, C.P.; Dias, Fabio Teixeira; Vieira, V.N.; da Silva, Douglas Langie; Schaf, Jacob; Wolff-Fabris, F.; Roa Rovira, Joan Josep (2013-05)
      Article
      Accés obert
      In this work we report on systematic field-cooled magnetization experiments in melt-textured YBa 2 Cu 3 O 7 − δ samples containing Y211 precipitates. Magnetic fields up to 14 T were applied either parallel or ...

    • Paramagnetic moments and time effects in melt-textured NdBaCuO system with Nd422 inclusions 

      Teixeira Dias, Fábio; Vieira, Valdemar das Neves; D. L., Silva; Wolff-Fabris, Frederik; Kampert, Erik; Almeida, M.L.; Mesquita, F; Hneda, M; Roa Rovira, Joan Josep (Institute of Physics (IOP), 2015)
      Article
      Accés obert
      We have performed magnetic measurements in two melt-textured NdBa2Cu3O7-d samples with Nd422 inclusions under magnetic fields from 0.05 up to 14 T, applied parallel to the ab planes. The measurements were made with a ...

    • Peptidic biofunctionalization of laser patterned dental zirconia: A biochemical-topographical approach 

      Minguela Díaz, Joaquim; Müller, D.W; Mücklich, Frank T.; Llanes Pitarch, Luis Miguel; Ginebra Molins, Maria Pau; Roa Rovira, Joan Josep; Mas Moruno, Carlos (Elsevier, 2021-06-01)
      Article
      Accés obert
      Realitzat a/amb:   Universität des Saarlandes / Institut de Bioenginyeria de Catalunya
      A dual approach employing peptidic biofunctionalization and laser micro-patterns on dental zirconia was explored, with the aim of providing a flexible tool to improve tissue integration of restorations. Direct ...

    • Performance and short-term stability of single chamber SOFCs based on La0.9Sr0.1Ga0.8Mg0.2O3-d electrolyte 

      Morales Comas, Miguel; Roa Rovira, Joan Josep; Tartaj, Jesus; Segarra Rubi, Merce (2012-10-15)
      Article
      Accés restringit per política de l'editorial
      In the present work, the performance of La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) electrolyte-supported SOFCs was evaluated under single-chamber conditions. For this purpose, two single cells, one with and the other without Sm0.2Ce0.8O3−δ ...

    • Performance of a novel type of electrolyte-supported solid oxide fuel cell with honeycomb structure 

      Ruíz-Morales, J.C.; Marrero-López, D.; Peña-Martínez, J.; Canales-Vázquez, Jesús; Roa Rovira, Joan Josep; Segarra, M.; Savvin, S.N.; Núñez, Pedro (2010-01-15)
      Article
      Accés restringit per política de l'editorial
      A novel design, alternative to the conventional electrolyte-supported solid oxide fuel cell (SOFC) is presented. In this new design, a honeycomb-electrolyte is fabricated from hexagonal cells, providing high mechanical ...

    • Phase transformation and residual stresses after laser surface modification of metastable austenitic stainless steel 

      Rezayat, Mohammad; Roa Rovira, Joan Josep; Mateo García, Antonio Manuel (American Institute of Physics (AIP), 2023)
      Text en actes de congrés
      Accés obert
      Laser surface modification treatments have been applied to samples of a metastable austenitic stainless steel AISI 301LN. The amount of residual stresses and the presence of induced a´-martensite phase on the surface and ...