Now showing items 147-166 of 292

    • Magnetic dipole super-resonances and their impact on mechanical forces at optical frequencies 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      Artificial magnetism enables various transformative optical phenomena, including negative refraction, Fano resonances, and unconventional nanoantennas, beamshapers, polarization transformers and perfect absorbers, and ...
    • Measurement of polarization dependent loss, polarization mode dispersion and group delay of optical components using swept optical single sideband modulated signals 

      Sagüés García, Mikel Upna; Pérez Echegoyen, Miguel; Loayssa Lara, Alayn Upna (Optical Society of America, 2008)   Artículo / Artikulua  OpenAccess
      We introduce a novel method for high wavelength-resolution measurement of polarization-averaged group delay, polarization dependent loss and polarization mode dispersion of optical components using swept optical single ...
    • Mechanical 144GHz beam steering with all-metallic epsilon-near-zero lens antenna 

      Pacheco Peña, Víctor Upna; Torres Landívar, Víctor Upna; Orazbayev, Bakhtiyar Upna; Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna; Sorolla Ayza, Mario Upna; Engheta, Nader (AIP Publishing, 2014)   Artículo / Artikulua  OpenAccess
      An all-metallic steerable beam antenna composed of an ε-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ0 = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides ...
    • A metamaterial T-junction power divider 

      Sáenz Sáinz, Elena Upna; Cantora Álvarez, Alejandro; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Maagt, Peter de (IEEE, 2007)   Artículo / Artikulua  OpenAccess
      A metamaterial based compact microstrip T-junction power divider working at 10 GHz is proposed. The metamaterial unit cell consists of microstrip gaps and via holes whose behavior is equivalent to the combination of ...
    • Metasurface-based ultrathin carpet cloaks for millimeter waves 

      Orazbayev, Bakhtiyar Upna; Mohammadi Estakhri, Nasim; Alù, Andrea; Beruete Díaz, Miguel Upna (2017)   Artículo / Artikulua  OpenAccess
      A metasurface carpet cloak for millimetre-wave range with polarization independent performance is experimentally demonstrated. It is shown that the cloak is able to mimic the ground plane by fully restoring the amplitude ...
    • Métodos de procesamiento y análisis de señales electromiográficas 

      Gila Useros, Luis; Malanda Trigueros, Armando Upna; Rodríguez Carreño, Ignacio Upna; Rodríguez Falces, Javier Upna; Navallas Irujo, Javier Upna (Gobierno de Navarra, 2009)   Artículo / Artikulua  OpenAccess
      La electromiografía clínica es una metodología de registro y análisis de la actividad bioeléctrica del músculo esquelético orientada al diagnóstico de las enfermedades neuromusculares. Las posibilidades de aplicación y el ...
    • Micro and nanostructured materials for the development of optical fibre sensors 

      Elosúa Aguado, César Upna; Arregui San Martín, Francisco Javier Upna; Del Villar, Ignacio Upna; Ruiz Zamarreño, Carlos Upna; Corres Sanz, Jesús María Upna; Bariáin Aisa, Cándido Upna; Goicoechea Fernández, Javier Upna; Hernáez Sáenz de Zaitigui, Miguel Upna; Rivero Fuente, Pedro Upna; Socorro Leránoz, Abián Bentor Upna; Urrutia Azcona, Aitor Upna; Sánchez Zábal, Pedro Upna; Zubiate Orzanco, Pablo Upna; López Torres, Diego Upna; Acha Morrás, Nerea de Upna; Ascorbe Muruzabal, Joaquín Upna; Ozcariz Celaya, Aritz Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The measurement of chemical and biomedical parameters can take advantage of the features exclusively offered by optical fibre: passive nature, electromagnetic immunity and chemical stability are some of the most relevant ...
    • Micro-displacement sensor based on a hollow-core photonic crystal fiber 

      Rodrigues Pinto, Ana Margarida Upna; López-Amo Sáinz, Manuel Upna; Baptista, José Manuel; Santos, José Luís; Frazão, Orlando (MDPI, 2012)   Artículo / Artikulua  OpenAccess
      A sensing head based on a hollow-core photonic crystal fiber for in-reflection measurement of micro-displacements is presented. The sensing structure takes advantage of the multimodal behavior of a short segment ...
    • Mid-infrared plasmonic inductors: enhancing inductance with meandering lines 

      Torres Landívar, Víctor Upna; Ortuño Molinero, Rubén Upna; Rodríguez Ulibarri, Pablo Upna; Beruete Díaz, Miguel Upna; Sorolla Ayza, Mario Upna; Griol, Amadeu; Martínez, Alejandro; Navarro Cía, Miguel Upna (Nature Publishing Group, 2014)   Artículo / Artikulua  OpenAccess
      We present a mid-infrared inductor that when applied to an extraordinary transmission hole array produces a strong redshift of the resonant peak accompanied by an unprecedented enlargement of the operation bandwidth. The ...
    • 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 ...