Now showing items 51-70 of 80

    • Influence of surface roughness measurement scale on radar backscattering in different agricultural soils 

      Martínez de Aguirre Escobar, Alejandro Upna; Álvarez-Mozos, Jesús Upna; Lievens, Hans; Verhoest, Niko E. C. (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      Soil surface roughness strongly affects the scattering of microwaves on the soil surface and determines the backscattering coefficient (σ 0 ) observed by radar sensors. Previous studies have shown important scale issues ...
    • Influence of surface roughness sample size for C-band SAR backscatter applications on agricultural soils 

      Martínez de Aguirre Escobar, Alejandro Upna; Álvarez-Mozos, Jesús Upna; Lievens, Hans; Verhoest, Niko E. C.; Giménez Díaz, Rafael Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      Soil surface roughness determines the backscatter coefficient observed by radar sensors. The objective of this letter was to determine the surface roughness sample size required in synthetic aperture radar applications and ...
    • Influence of surface roughness spatial variability and temporal dynamics on the retrieval of soil moisture from SAR observations 

      Álvarez-Mozos, Jesús Upna; Verhoest, Niko E. C.; Larrañaga, Arantzazu Upna; Casalí Sarasíbar, Javier Upna; González de Audícana Amenábar, María Upna (MDPI, 2009)   Artículo / Artikulua  OpenAccess
      Radar-based surface soil moisture retrieval has been subject of intense research during the last decades. However, several difficulties hamper the operational estimation of soil moisture based on currently available ...
    • Magnesium oxide as alternative binder for unfired clay bricks manufacturing 

      Espuelas Zuazu, Sandra Upna; Omer, Joshua; Marcelino Sádaba, Sara Upna; Echeverría, Angel María; Seco Meneses, Andrés Upna (Elsevier, 2017)   Artículo / Artikulua  OpenAccess
      Replacement of fired bricks by unfired ones could be an effective way to reduce the building industryenvironmental footprint: Their manufacture not only requires less energy and natural resources but alsogenerates less waste. ...
    • Mathematical models to describe the volumetric shrinkage rate of red beans during drying 

      Correa, P. C.; Resende, O.; Arazuri Garín, Silvia Upna; Jarén Ceballos, Carmen Upna; Oliveira, Gabriel H. H. de (Associação Brasileira de Engenharia Agrícola, 2011)   Artículo / Artikulua  OpenAccess
      The present study aimed to determine the volumetric shrinkage rate of bean (Phaseolus vulgaris L.) seeds during air-drying under different conditions of air, temperature and relative humidity, and to adjust several ...
    • Metodología interna en la formación académica 

      Martínez Ilundáin, José Manuel Upna (2014)   Tesis doctoral / Doktoretza tesia  OpenAccess
      Se define la metodología interna de la formación académica como un plan de investigación que permite mejorar el rendimiento académico de una forma continua y autónoma. Por tanto, dicha metodología permite al docente ...
    • Monitoring water vapour with GNSS during a heavy rainfall event in the Spanish Mediterranean area 

      Priego, E.; Jones, J.; Porres, M. J.; Seco Meneses, Andrés Upna (Taylor & Francis, 2017)   Artículo / Artikulua  OpenAccess
      The Spanish Mediterranean area is periodically affected by torrential rainfall events during autumn. In September 2012, one of these episodes took place with up to 50 mm of rain in a 1-hour period and with more than 300 ...
    • Multi-criteria evaluation of topographic correction methods 

      Sola Torralba, Ion Upna; González de Audícana Amenábar, María Upna; Álvarez-Mozos, Jesús Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      In the last decades, several topographic correction methods (TOC) have been proposed, but there is not an agreement on the best method. Furthermore, different evaluation criteria have been used in the past, and there is ...
    • A multi-year analysis of traffic accidents involving agricultural tractors 

      Arnal Atarés, Pedro Upna; López-Maestresalas, Ainara Upna; Arazuri Garín, Silvia Upna; Mangado Ederra, Jesús Upna; Jarén Ceballos, Carmen Upna (AIDIC, 2017)   Artículo / Artikulua  OpenAccess
      The agricultural sector in Spain is responsible for a high rate of accidents every year, and many of them are traffic accidents. Tractors are a relatively rare sight on roads, meaning that the incidence of accidents involving ...
    • Multitemporal evaluation of topographic correction algorithms using synthetic images 

      Sola Torralba, Ion Upna; Álvarez-Mozos, Jesús Upna; González de Audícana Amenábar, María Upna; Torres Escribano, José Luis Upna (SPIE, 2012)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Land cover classification and quantitative analysis of multispectral data in mountainous regions is considerably hampered by the influence of topography on the spectral response pattern. In the last years, different ...
    • Near-infrared spectroscopy and hyperspectral imaging for non-destructive quality inspection of potatoes 

      López-Maestresalas, Ainara Upna (2016)   Tesis doctoral / Doktoretza tesia  OpenAccess
      La patata (Solanum tuberosum L.) es uno de los cultivos más importantes en el mundo, ocupando el quinto puesto en términos de producción. España es uno de los países europeos con mayor producción y consumo de estos tubérculos. ...
    • Non-destructive detection of blackspot in potatoes by Vis-NIR and SWIR hyperspectral imaging 

      López-Maestresalas, Ainara Upna; Keresztes, Janos C.; Goodarzi, Mohammad; Arazuri Garín, Silvia Upna; Jarén Ceballos, Carmen Upna; Saeys, Wouter (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      Blackspot is a subsurface potato damage resulting from impacts during harvesting. This type of bruising represents substantial economic losses every year. As the tubers do not show external symptoms, bruise detection in ...
    • On the added value of quad-pol data in a multi-temporal crop classification framework based on RADARSAT-2 imagery 

      Larrañaga, Arantzazu Upna; Álvarez-Mozos, Jesús Upna (MDPI, 2016)   Artículo / Artikulua  OpenAccess
      Polarimetric SAR images are a rich data source for crop mapping. However, quad-pol sensors have some limitations due to their complexity, increased data rate, and reduced coverage and revisit time. The main objective of ...
    • On the assimilation set-up of ASCAT soil moisture data for improving streamflow catchment simulation 

      Loizu Maeztu, Javier Upna; Massari, Christian; Álvarez-Mozos, Jesús Upna; Tarpanelli, Angelica; Brocca, Luca; Casalí Sarasíbar, Javier Upna (Elsevier, 2018)   Artículo / Artikulua
      Assimilation of remotely sensed surface soil moisture (SSM) data into hydrological catchment models has been identified as a means to improve stream flow simulations, but reported results vary markedly depending on the ...
    • On the soil roughness parameterization problem in soil moisture retrieval of bare surfaces from synthetic aperture radar 

      Verhoest, Niko E. C.; Lievens, Hans; Wagner, Wolfgang; Álvarez-Mozos, Jesús Upna; Moran, M. Susan; Mattia, Francesco (MDPI, 2008)   Artículo / Artikulua  OpenAccess
      Synthetic Aperture Radar has shown its large potential for retrieving soil moisture maps at regional scales. However, since the backscattered signal is determined by several surface characteristics, the retrieval of soil ...
    • Phytochemicals determination and classification in purple and red fleshed potato tubers by analytical methods and near infrared spectroscopy 

      Tierno, Roberto; López-Maestresalas, Ainara Upna; Riga, Patrick; Arazuri Garín, Silvia Upna; Jarén Ceballos, Carmen Upna; Ruiz de Galarreta, José Ignacio Upna (Wiley, 2016)   Artículo / Artikulua  OpenAccess
      BACKGROUND: Over the last two decades, the attractive colours and shapes of pigmented tubers and the increasing concern about the relationship between nutrition and health have contributed to the expansion of their ...
    • Prediction of main potato compounds by NIRS 

      López-Maestresalas, Ainara Upna; Pérez Roncal, Claudia Upna; Tierno, Roberto; Arazuri Garín, Silvia Upna; Ruiz de Galarreta, José Ignacio Upna; Jarén Ceballos, Carmen Upna (AIDIC, 2017)   Artículo / Artikulua  OpenAccess
      Potato (Solanum tuberosum, L) compounds are generally determined by analytical methods including gasliquid chromatography (GLC), HPLC and UV-VIS spectrophotometry. These methods require a lot of time and are destructive. ...
    • Progress in gully erosion research: IV International Symposium on Gully Erosion 

      Casalí Sarasíbar, Javier Upna; Giménez Díaz, Rafael Upna (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007)   Libro / Liburua  OpenAccess
      The classic forms of water erosion of the soil comprise sheet, rill, and gully erosion. According to the concept most generalized, in sheet erosion, thin layers of material are uniformly removed from the soil surface due ...
    • Project management in development cooperation. Non-governmental organizations 

      Montes Guerra, Maricela I.; Romero de Miguel, Aida; Pérez Ezcurdia, Amaya Upna; Gimena Ramos, Faustino Upna; Díez Silva, H. Mauricio (Universidad Nacional de Colombia, 2015)   Artículo / Artikulua  OpenAccess
      Este artículo analiza la adopción de prácticas propias de la gestión de proyectos en las ONG destinadas a la cooperación para el desarrollo, así como su influencia en la ejecución y el impacto de la aplicación de metodologías, ...
    • Residual stresses with time-independent cyclic plasticity in finite element analysis of welded joints 

      Lostado Lorza, Rubén; Corral Bobadilla, Marina; Martínez Calvo, María Ángeles; Villanueva Roldán, Pedro Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Due to the intense concentration of heat in a reduced area when Gas Metal Arc Welding (GMAW) is used to join mechanical components, the regions near the weld bead are subjected to severe thermal cycles. Firstly, the region ...