Now showing items 159-178 of 297

    • Millimeter-wave phase resonances in compound reflection gratings with subwavelength grooves 

      Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna; Skigin, Diana C.; Sorolla Ayza, Mario Upna (Optical Society of America, 2010)   Artículo / Artikulua  OpenAccess
      Experimental evidence of phase resonances in a dual-period reflection structure comprising three subwavelength grooves in each period is provided in the millimeter-wave regime. We have analyzed and measured the response ...
    • Mode transition in complex refractive index coated single-mode–multimode–single-mode structure 

      Socorro Leránoz, Abián Bentor Upna; Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      By coating a single-mode–multimode–single-mode (SMS) structure with a high refractive index thin-film it is possible to obtain a transition of modes for specific combinations of thin-film thickness, thinfilm refractive ...
    • Modeling of small wind turbines based on PMSG with diode bridge for sensorless maximum power tracking 

      Urtasun Erburu, Andoni Upna; Sanchis Gúrpide, Pablo Upna; San Martín Biurrun, Idoia Upna; López Taberna, Jesús; Marroyo Palomo, Luis Upna (Elsevier, 2013)   Artículo / Artikulua  OpenAccess
      The Permanent Magnet Synchronous Generator (PMSG) with diode bridge is frequently used in small Wind Energy Conversion Systems (WECS). This configuration is robust and cheap, and therefore suitable for small WECS. In order ...
    • Modelling fibrillation potentials: analysis of time parameters in the muscle intracellular action potential 

      Rodríguez Falces, Javier Upna; Malanda Trigueros, Armando Upna; Gila Useros, Luis; Rodríguez Carreño, Ignacio Upna; Navallas Irujo, Javier Upna (IEEE, 2007)   Artículo / Artikulua  OpenAccess
      A single fibre action potential (SFAP) can be modelled as the convolution of a biolectrical source and a filter impulse response. In the Dimitrov-Dimitrova (D-D) convolutional model, the first temporal ...
    • Modelling of PEM fuel cell performance: steady-state and dynamic experimental validation 

      San Martín Biurrun, Idoia Upna; Ursúa Rubio, Alfredo Upna; Sanchis Gúrpide, Pablo Upna (MDPI, 2014)   Artículo / Artikulua  OpenAccess
      This paper reports on the modelling of a commercial 1.2 kW proton exchange membrane fuel cell (PEMFC), based on interrelated electrical and thermal models. The electrical model proposed is based on the integration of the ...
    • Models for gaze tracking systems 

      Villanueva Larre, Arantxa Upna; Cabeza Laguna, Rafael Upna (Hindawi Publishing Corporation, 2007)   Artículo / Artikulua  OpenAccess
      One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, ...
    • A modified control scheme of droop-based converters for power stability analysis in microgrids 

      Usunáriz López, Igor; Santamaría Rubio, Mikel; Mentesidi, Konstantina; Aguado Alonso, Mónica Upna (Hindawi / Wiley, 2015)   Artículo / Artikulua  OpenAccess
      Microgrid is principally an active distribution network since it aggregates numerous DG systems through their interface converters and different loads at distribution level. This paper discusses the power sharing in ...
    • Monitorización de deformaciones y temperaturas en la estructura de un túnel artificial de alta velocidad mediante sensores ópticos puntuales, de longitud y distribuidos 

      Torres, B.; Payá Zaforteza, I.; Barrera, D.; Alvarado, Y. A.; Calderón, P. A.; Loayssa Lara, Alayn Upna; Sagüés García, Mikel Upna; Zornoza Indart, Ander; Sales, S. (CSIC, 2015)   Artículo / Artikulua  OpenAccess
      La monitorización de estructuras es una rama de la ingeniería estructural que está captando mucha atención actualmente. Las deformaciones y temperaturas son, habitualmente, los parámetros monitorizados porque son los que ...
    • Motor unit action potential duration, I: variability of manual and automatic measurements 

      Rodríguez Carreño, Ignacio Upna; Gila Useros, Luis; Malanda Trigueros, Armando Upna; García Gurtubay, Ignacio; Mallor Giménez, Fermín Upna; Gómez Elvira, Sagrario Upna; Rodríguez Falces, Javier Upna; Navallas Irujo, Javier Upna (Lippincott, Williams & Wilkins, 2007)   Artículo / Artikulua  OpenAccess
      To analyze the variability in manual measurements of motor unit action potential (MUAP) duration and to evaluate the effectiveness of well-known algorithms for automatic measurement. Two electromyographists carried out ...
    • Motor unit action potential duration, II: a new automatic measurement method based on the wavelet transform 

      Rodríguez Carreño, Ignacio Upna; Gila Useros, Luis; Malanda Trigueros, Armando Upna; García Gurtubay, Ignacio; Mallor Giménez, Fermín Upna; Gómez Elvira, Sagrario Upna; Rodríguez Falces, Javier Upna; Navallas Irujo, Javier Upna (Lippincott, Williams & Wilkins, 2007)   Artículo / Artikulua  OpenAccess
      To present and evaluate a new algorithm, based on the wavelet transform, for the automatic measurement of motor unit action potential (MUAP) duration. A total of 240 MUAPs were studied. The waveform of each MUAP was ...
    • Multi-tap complex-coefficient incoherent microwave photonic filters based on optical single-sideband modulation and narrow band optical filtering 

      Sagüés García, Mikel Upna; García Olcina, Raimundo; Loayssa Lara, Alayn Upna; Sales, S.; Capmany, José (Optical Society of America, 2008)   Artículo / Artikulua  OpenAccess
      We propose a novel scheme to implement tunable multi-tap complex coefficient filters based on optical single sideband modulation and narrow band optical filtering. A four tap filter is experimentally demonstrated to ...
    • Multiband one-way polarization conversion in complementary split-ring resonator based structures by combining chirality and tunneling 

      Serebryannikov, Andriy E.; Beruete Díaz, Miguel Upna; Mutlu, Mehmet; Ozbay, Ekmel (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      Multiband one-way polarization conversion and strong asymmetry in transmission inspired by it are demonstrated in ultrathin sandwiched structures that comprise two twisted aperture-type arrays of complementary split-ring ...
    • Multicolor layer-by-layer films using weak polyelectrolyte assisted synthesis of silver nanoparticles 

      Rivero Fuente, Pedro José Upna; Goicoechea Fernández, Javier Upna; Urrutia Azcona, Aitor Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (Springer, 2013)   Artículo / Artikulua  OpenAccess
      In the present study, we show that silver nanoparticles (AgNPs) with different shape, aggregation state and color (violet, green, orange) have been successfully incorporated into polyelectrolyte multilayer thin films using ...
    • Multifrequency focusing and wide angular scanning of terajets 

      Pacheco Peña, Víctor Upna; Beruete Díaz, Miguel Upna; Minin, Igor V.; Minin, Oleg V. (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      In the past, it has been demonstrated that it is possible to produce terajets with high resolution at its focus using 3D dielectric cuboids under plane-wave illumination. Here, a systematic study of the harmonic and angular ...
    • Multiplexing of six micro-displacement suspended-core Sagnac interferometer sensors with a Raman-Erbium fiber laser 

      Bravo Acha, Mikel Upna; Fernández Vallejo, Montserrat Upna; Echapare Zabaleta, Mikel; López-Amo Sáinz, Manuel Upna; Kobelke, J.; Schuster, K. (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      This work experimentally demonstrates a long-range optical fiber sensing network for the multiplexing of fiber sensors based on photonic crystal fibers. Specifically, six photonic crystal fiber sensors which are based ...
    • A multipolar analysis of near-field absorption and scattering processes 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2013)   Artículo / Artikulua  OpenAccess
      A multipolar formulation is adopted to investigate the absorption and scattering processes involved in near-field interactions. This approach allows one to determine the upper bounds for the absorbed and radiated powers ...
    • Nanodeposition of materials with complex refractive index in long period fiber gratings 

      Del Villar, Ignacio Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Achaerandio, Miguel Upna (IEEE, 2005)   Artículo / Artikulua  OpenAccess
      An overlay of higher refractive index than the cladding is deposited on a Long Period Fiber Grating (LPFG). This permits to improve in a great manner the sensitivity of the device to ambient and overlay refractive index ...
    • Nanofabrication of phase-shifted Bragg gratings on the end facet of multimode fiber towards development of optical filters and sensors 

      Gallego, E.E.; Ascorbe Muruzabal, Joaquín Upna; Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (Elsevier, 2018)   Artículo / Artikulua
      This work describes the process of nanofabrication of phase-shifted Bragg gratings on the end facet of a multimode optical fiber with a pulsed DC sputtering system based on a single target. Several structures have been ...
    • Nanofilms on a hollow core fiber 

      Matías Maestro, Ignacio Upna; Bravo Larrea, Javier Upna; Arregui San Martín, Francisco Javier Upna; Corres Sanz, Jesús María Upna (SPIE, 2006)   Artículo / Artikulua  OpenAccess
      We experimentally study the behavior of one multimode fiber–hollow core fiber–multimode fiber structure when nanofilms are deposited on it with the aim of developing practical evanescent field-based devices, such as sensors, ...
    • Nanomaterials for functional textiles and fibers 

      Rivero Fuente, Pedro José Upna; Urrutia Azcona, Aitor Upna; Goicoechea Fernández, Javier Upna; Arregui San Martín, Francisco Javier Upna (Springer US, 2015)   Artículo / Artikulua  OpenAccess
      Nanoparticles are very interesting because of their surface properties, different from bulk materials. Such properties make possible to endow ordinary products with new functionalities. Their relatively low cost with ...