Development of a global burned area mapping algorithm for moderate spatial resolution optical sensors

La tesis doctoral titulada “Development of a global burned area mapping algorithm for moderate spatial resolution optical sensors” propone el desarrollo de un algoritmo de detección de área quemada global para sensores ópticos de resolución espacial moderada. El trabajo ha sido financiado y desarrollado bajo los proyectos Fire Disturbance (FireCCI) del programa Climate Change Initiative (CCI) de la European Space Agency (ESA) y el Copernicus Climate Change Service (C3S) de la European Commission (EC). El autor de este trabajo también ha recibido financiación del Ministerio de Ciencia, Innovación y Universidades, a través de una beca FPU. Cuando se propuso esta tesis solo había un único producto global de área quemada que ofrecía una serie temporal larga y consistente. Se trataba del producto MCD64A1 de la National Aeronautics and Space Administration (NASA) que se generaba operacionalmente y que proveía información de área quemada a nivel global a 500 m desde noviembre del 2000. Por la parte europea solo había dos productos, el FireCCI41 y el GIO_GL1_BA, pero se trataba de productos que o bien ofrecían una serie temporal demasiado reducida (FireCCI41) o bien una serie con baja fiabilidad. En cualquier caso, los tres productos, incluido el MCD64A1, presentaban limitaciones que les hacían estar lejos de cumplir los requerimientos establecidos por los usuarios en términos de errores de comisión y omisión. Es en este contexto donde se plantea esta tesis que pretende avanzar en el conocimiento de los algoritmos de área quemada globales y la generación de productos globales que cumplan o se acerquen de forma más significativa a las expectativas de los usuarios. Para este propósito, se ha utilizado información proveniente de sensores que no se habían utilizado hasta el momento para generar productos de área quemada globales. Esta información incluye las bandas de alta resolución a 250 m del Moderate Resolution Imaging Spectroradiometer (MODIS), las bandas del Ocean and Land Colour Instrument (OLCI) y del SYNERGY, así como fuegos activos de MODIS y del Visible Infrared Imaging Radiometer Suite (VIIRS). En este último caso, ha sido la primera vez que se utilizan globalmente para generar este tipo de productos. Así, se han desarrollado cuatro algoritmos y se han generado sus respectivos productos de área quemada a escala global. Cada uno de ellos ha jugado un papel complementario al resto, ya sea a modo de versión mejorada o como adaptación de un mismo algoritmo a distintos sensores. Todos los productos derivados han sido validados globalmente y se han llevado a cabo comparaciones exhaustivas con otros productos existentes. Además, para confirmar la estabilidad de los patrones espacio temporales, los productos se han aplicado para dar respuesta a distintas preguntas científicas relacionadas con las anomalías en las tendencias del área quemada en distintas partes del mundo. Para explicar todo este proceso la tesis se ha estructurado en ocho capítulos: introducción, seis publicaciones en revistas internacionales y unas conclusiones

PLLA/ZnO nanocomposites: dynamic surfaces to harness cell differentiation

This work investigates the effect of the sequential availability of ZnO nanoparticles, (nanorods of ∼40 nm) loaded within a degradable poly(lactic acid) (PLLA) matrix, in cell differentiation. The system constitutes a dynamic surface, in which nanoparticles are exposed as the polymer matrix degrades. ZnO nanoparticles were loaded into PLLA and the system was measured at different time points to characterise the time evolution of the physicochemical properties, including wettability and thermal properties. The micro and nanostructure were also investigated using AFM, SEM and TEM images. Cellular experiments with C2C12 myoblasts show that cell differentiation was significantly enhanced on ZnO nanoparticles—loaded PLLA, as the polymer degrades and the availability of nanoparticles become more apparent, whereas the release of zinc within the culture medium was negligible. Our results suggest PLLA/ZnO nanocomposites can be used as a dynamic system where nanoparticles are exposed during degradation, activating the material surface and driving cell differentiation

Implementation of the PBL methodology in courses of Construction I-II

This paper explains the way in which matters Construction-I and Construction-II have been given, in the Degree of Architecture of the Higher Technical School of Architecture in San Sebastian, during 2015-16, by using for the first time a Project Based Learning (PBL) active methodology. The methodology was implemented during the first four-month period in matter Construction-I, within the framework of the "training program of professors in active teaching methodologies ERAGIN" by the University of the Basque Country. At the conclusion, after an analysis of the developed work and taking into account the good performance results, teachers decided to continue applying the PBL methodology in matter Construction-II, in the second four-month period, making some minor adjustments in order to correct mistakes and to optimize its application. The final result was positive, and the experience will be useful to make a future common design of both matters, based on the same methodology.El artículo expone el modo en el que se han impartido las asignaturas Construcción-I y Construcción-II, de 3er curso del Grado en Fundamentos de Arquitectura de la ETSA de Donostia-San Sebastián (EHU/UPV), durante el curso 2015-16, utilizando por 1ª vez la metodología activa ABP (Aprendizaje Basado en Proyectos). Su implantación en Construcción-I durante el 1er cuatrimestre del curso se realizó en el marco del “Programa de formación del profesorado en metodologías activas de enseñanza ERAGIN” de EHU/UPV. A su conclusión, tras un análisis del trabajo desarrollado y los buenos resultados obtenidos, se decidió continuar con la metodología PBL en la asignatura Construcción II del 2º cuatrimestre realizando una serie de pequeños cambios para corregir errores y optimizar su aplicación. Los resultados finales han sido también muy positivos y la experiencia servirá para realizar un diseño unificado de ambas asignaturas basado en la misma metodología en los próximos cursos

Selection of the number of frequencies using bootstrap techniques in log-periodogram regression

The choice of the bandwidth in the local log-periodogram regression is of crucial importance for estimation of the memory parameter of a long memory time series. Different choices may give rise to completely different estimates, which may lead to contradictory conclusions, for example about the stationarity of the series. We propose here a data driven bandwidth selection strategy that is based on minimizing a bootstrap approximation of the mean squared error and compare its performance with other existing techniques for optimal bandwidth selection in a mean squared error sense, revealing its better performance in a wider class of models. The empirical applicability of the proposed strategy is shown with two examples: the widely analyzed in a long memory context Nile river annual minimum levels and the input gas rate series of Box and Jenkins.bootstrap, long memory, log-periodogram regression, bandwidth selection

Advances, challenges, and environmental impacts in metal-air battery electrolytes

Efficient energy storage technologies are vital in the current efforts towards decarbonisation. Batteries, as one of the most versatile electrochemical energy storage systems, have the potential to shape the transition from the current climate crisis scenario to a carbon neutral and sustainable future. In particular, metal-air batteries are gaining scientific and industrial interest as promising contenders to the ubiquitous lithium-ion batteries. The electrolyte plays a critical role in metal-air batteries as it determines the battery performance, its safety and the operating lifespan. The low-density, ease of processing, good thermal and electrochemical stability, mechanically stiff but ductile character, electrically insulating properties and tailor-made chemistry make polymers singularly interesting to be applied as a separator/liquid electrolyte pair, gel-electrolytes or solid-electrolytes. Accordingly, in this work the current bottlenecks and challenges in metal-air batteries are presented, with particular emphasis on the electrolyte design. The implementation of aqueous liquid electrolytes, organic liquid electrolytes, polymer membranes soaked in liquid electrolytes, gel-like electrolytes and solid-state electrolytes is discussed and the environmental impacts associated with metal-air batteries are analysed within a Circular Economy perspective. We expect this work can guide future efforts in the development of potentially sustainable next generation metal-air batteries

La competencia de la escritura manual en el currículo: un nuevo enfoque

La enseñanza de la escritura manuscrita ha quedado marginada en el currículo por dos causas principales: la importancia que se la ha dado a la composición-construcción y el auge de las nuevas tecnologías. A los numerosos debates en torno a la enseñanza de la escritura manual (p.e. tipo de letra, uniones, tipos de hoja, paradigma clásico o constructivista) se les ha añadido un nuevo interrogante en el contexto internacional: ¿hay que evaluar la calidad o la automaticidad de la escritura? Está demostrado que mediante el desarrollo de la automaticidad en la escritura manual los estudiantes se pueden concentrar mejor y pueden emplear sus habilidades del lenguaje para producir textos más largos y de mejor calidad. Pero.. ¿incluyen los currículos medidas para que los alumnos consigan esta automaticidad? En esta comunicación se ofrecen guías para ello.EHU-UP

Environmental Impact Assessment of Chitin Nanofibril and Nanocrystal Isolation from Fungi, Shrimp Shells, and Crab Shells

Chitin nanoparticles are responsible for the outstanding mechanical properties found in the exoskeletons of crustaceans and are finding applications in many scientific and technological fields. Following a Circular Economy approach, diverse biomass wastes can be valorized to be reintroduced back into the economic cycle while preventing biowaste landfill upon isolation of chitin nanoparticles. Novel environmentally sustainable paths over the conventional chitin nanoparticle extraction involving harsh acid-hydrolysis treatments from crustacean shells have been recently proposed. In particular, fungi emerge as an attractive alternative provided the demineralization process with acids such as HCl is circumvented. In spite of this recognized virtue, no works have quantified the environmental impacts of these processes. The life-cycle assessment methodology is applied to close this gap and quantify the cradle-to-gate impacts of chitin nanofibril extraction from fungi. The results are compared to conventional chitin nanocrystal hydrolytic isolation processes from shrimp shells, chitin powder, and crab shells, together with sulfuric-acid-induced hydrolysis of microcrystalline cellulose to cellulose nanocrystals. Eighteen impact indicators are analyzed scaling-up laboratory quantities into processes treating 1 kg of biowastes. A global warming potential value of 18.5 kg center dot CO2-equiv per 1 kg of chitin nanofibrils is obtained, well below the 906.8, 105.2, 543.5, and 177.9 kg CO2- equiv center dot kg-1 values obtained for chitin nanocrystals from shrimp shells, chitin powder, crab shells, and cellulose nanocrystals, respectively. A sensitivity analysis shows a 10.1-62.6% impact decrease to a minimum value of 14.7 kg CO2-equiv center dot kg-1 for chitin nanofibril isolation from fungi considering 95% recirculation of the solvent/NaOH, highlighting the environmentally sustainable character of chitin nanofibril extraction from fungi. The potential application of chitin nanoparticles into environmentally sustainable materials and devices is explored. These results provide novel cues for the environmentally friendly synthesis of nanochitin, guiding the implementation of sustainable approaches in the field of biomass nanoparticles.The authors are grateful for the financial support from the 2021 Euskampus Missions 1.0. Programme granted by Euskampus Fundazioa and the University of the Basque Country (Convocatoria de ayudas a grupos de investigacion GIU21/010) . The authors also acknowledge the Open Access funding provided by the UPV/EHU

Synergic Effect of Nanolignin and Metal Oxide Nanoparticles into Poly(l-lactide) Bionanocomposites: Material Properties, Antioxidant Activity, and Antibacterial Performance

Binary and ternary poly (L-lactide) (PLLA) based nanocomposites, containing nanolignin (1% wt.) and different metal oxide nanoparticles (0.5% wt., Ag2O, TiO2, WO3, Fe2O3 and ZnFe2O4) were realized ..

Environmental Impact Assessment of Solid Polymer Electrolytes for Solid-State Lithium Batteries

Solid-state batteries play a pivotal role in the next-generation batteries as they satisfy the stringent safety requirements for stationary or electric vehicle applications. Notable efforts are devoted to the competitive design of solid polymer electrolytes (SPEs) acting as both the electrolyte and the separator. Although particular efforts to attain acceptable ionic conductivities and wide electrochemical stability widows are carried out, the environmental sustainability is largely neglected. To address this gap, here the cradle-to-gate environmental impacts of the most representative SPEs using life cycle assessment (LCA) are quantified. Raw material extraction and electrolyte fabrication are considered. Global warming potential values of 0.37–10.64 kg CO2 equiv. gelectrolyte −1 are achieved, where PEO/LiTFSI presents the lower environmental burdens. A minor role of the polymer fraction on the total impacts is observed, with a maximum CO2 footprint share of 0.61%. Following ecodesign approaches, a sensitivity analysis is performed to simulate industrial-scale fabrication processes and explore environmentally friendlier scenarios. The electrochemical performance of SPEs is further analyzed into Li/LiFePO4 solid lithium metal battery cell configuration. Overall, these results are aimed to guide the ecologically sustainable design of SPEs and facilitate the implementation of next-generation sustainable batteries.The authors gratefully acknowledge support from Siemens Gamesa (Students4Sustainability Grant) and 4GUNE (Clúster de Ingeniería, Ciencia y Tecnología de Euskadi). The authors are also grateful for the Open Access funding provided by the University of Basque Country (UPV/EHU)

Selection of the number of frequencies using bootstrap techniques in log-periodogram regression

The choice of the bandwidth in the local log-periodogram regression is of crucial importance for estimation of the memory parameter of a long memory time series. Different choices may give rise to completely different estimates, which may lead to contradictory conclusions, for example about the stationarity of the series. We propose here a data driven bandwidth selection strategy that is based on minimizing a bootstrap approximation of the mean squared error and compare its performance with other existing techniques for optimal bandwidth selection in a mean squared error sense, revealing its better performance in a wider class of models. The empirical applicability of the proposed strategy is shown with two examples: the widely analyzed in a long memory context Nile river annual minimum levels and the input gas rate series of Box and Jenkins.Research supported by the Ministerio de Ciencia y Tecnología and FEDER grant SEJ2007-61362, and by the Department of Education of the Basque Government grant IT-334-07 (UPV/EHU Econometrics Research Group)