Investigation of GLM detections of negative continuing currents observed by high-speed video and narrow-band 777 nm photometer

Lightning flashes with continuing currents are characterized by high energy transfer to ground that produces severe damage to electric power systems. Novel space-based optical lightning detection systems offer new possibilities to identify flashes with continuing currents. In this work, we analyze the Geostationary Lightning Mapper (GLM) detections of ten negative cloud-to-ground flashes observed from ground by a high-speed camera and a photometer. Results show that 10 out of 25 of the observed negative CG flashes produced continuing currents. In 6 out of 11 of the observed continuing currents, GLM provided more than four consecutive detections of events. The average duration of continuous detection of GLM events during continuing currents represents 10 % of the total duration of the continuing currents. The GLM detection limits compared with ground-based-optical instruments is related to the GLM sensitivity threshold. Additional Colombia Lightning Mapping Array data revealed that in-cloud positive leaders associated with the continuing currents propagate at low altitudes, corresponding to the midlevel negative charge region. The development of these leaders at low altitudes, along with weaker negative continuing currents levels compared to positive flashes, makes them challenging to detect by GLM. This work provides insights into the interpretation of space-based continuing currents optical detection.ESP2017-86263-C4-2-R funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe", by the "European Union"; grants PIDP2019109269RB-C42, PID2022-136348NBC32, and EQC2021-006957-P funded by MCIN/AEI/ and Grant 2020 FI-B 00533 by AGAUR. The authors are grateful to Keraunos SAS (Colombia) for pro- viding lightning data of LINET. This research has been developed in the context of the CIGRE SC4 WG70.Peer ReviewedPostprint (published version

Direct Ink Writing of cobalt-zirconia monoliths for catalytic applications: a novel single-step fabrication approach

Additive manufacturing technologies are revolutionizing the fabrication of ceramic catalysts through hierarchical design to enhance catalytic performance and simultaneously improving the efficiency of the manufacturing process by decreasing the initial investment and production steps. This work proposes a fabrication process of cobalt-zirconia monoliths based on Direct-Ink Writing of Co-enriched hydrogel-based ceramic inks, and the debinding and sintering at 600ºC in a single thermal treatment. The effect of Co precursor amount (3.0¿-7.0¿wt% Co) on the rheological properties of inks and the catalytic performance in ethanol steam reforming is investigated. The results reveal the successful incorporation of Co into rectilinear monoliths with 50¿% infill, obtaining strongly Co-rich surfaces. The remarkable catalytic performance of the 5.0¿wt% Co monolith at 300–600ºC confirms the feasibility of this novel single-step approach, reaching an appropriate balance between catalytic activity and printability. This outcome may represent a push towards the fabrication of fully 3D-printed monolithic catalysts.Peer ReviewedPostprint (published version

El minifundio y la huerta

Twenty-five years after its creation, the Baix Llobregat Agricultural Park remains a relevant case in planning and managing peri-urban agricultural land. Besides being a land-use protection mechanism, the ‘agricultural park’ as a planning figure aims to dynamize its productive, morphological, and natural assets. Within the current debate on the agroecological transition, climate change, and local agri-food systems, this case becomes more relevant given that various scales of horticultural and fruit production play a role in the local agri-food system. This analysis constructs socio-spatial relationships inside and outside the park. It demonstrates that through the relationship between land tenure, land management, and production systems, issues and challenges emerge that can feed the debate on planning peri-urban agrarian spaces and the challenges faced by local production systems.Veinticinco años después de su conformación, el Parque Agrario del Baix Llobregat es aún relevante en cuanto ordenamiento y gestión del territorio agrario periurbano. La figura de ‘parque agrario’ además de ser un mecanismo de protección del suelo pretende dinamizar sus valores productivos, morfológicos, y naturales. En el debate sobre la transición agroecológica, el cambio climático y los sistemas agroalimentarios locales, este caso cobra mayor relevancia ya que su producción hortícola y frutícola, a través de distintas escalas de producción, cumplen un rol importante en el sistema agroalimentario local. Este análisis construye relaciones socioespaciales dentro y fuera del parque y demuestra que, a través de la estrecha relación entre las formas de tenencia y gestión de la tierra con los sistemas de producción, emergen cuestiones y desafíos que pueden nutrir el debate sobre el ordenamiento de los espacios agrarios periurbanos y el reto que enfrentan los sistemas de producción local.Peer Reviewe

A novel non-invasive optical framework for simultaneous analysis of contractility and calcium in single-cell cardiomyocytes

The use of a video method based on the Digital Image Correlation (DIC) algorithm from experimental mechanics to estimate the displacements, strain field, and sarcolemma length in a beating single-cell cardiomyocyte is proposed in this work. The obtained deformation is then correlated with the calcium signal, from calcium imaging where fluorescent dyes sensitive to calcium Ca2+ are used. Our proposed video-based method for simultaneous contraction and intracellular calcium analysis results in a low-cost, non-invasive, and label-free method. This technique has shown great advantages in long-term observations because this type of intervention-free measurement neutralizes the possible alteration in the beating cardiomyocyte introduced by other techniques for measuring cell contractility (e.g., Traction Force Microscopy, Atomic Force Microscopy, Microfabrication or Optical tweezers). Three tests were performed with synthetically augmented data from cardiomyocyte images to validate the robustness of the algorithm. First, a simulated rigid translation of a referenced image is applied, then a rotation, and finally a controlled longitudinal deformation of the referenced image, thus simulating a native realistic deformation. Finally, the proposed framework is evaluated with real experimental data. To validate contraction induced by intracellular calcium concentration, this signal is correlated with a new deformation measure proposed in this article, which is independent of cell orientation in the imaging setup. Finally, based on the displacements obtained by the DIC algorithm, the change in sarcolemma length in a contracting cardiomyocyte is calculated and its temporal correlation with the calcium signal is obtained.This research was funded by the Spanish Ministry of Science and Innovation, grant numbers: PID2020-116927RB-C21, PID2020-116927RB-C22 and PID2023-152610OB-C21.Peer ReviewedPostprint (published version

News aesthetics of urban dwell

We present results of a research that investigated urban collective forms in consolidated areas of the city of Montevideo. We carry out a series of ethnographic explorations, focusing on social situations that involve various groups. We engaged with neighborhood collectives that intervene creatively in the urban territory. We take three key cases that imply new aesthetics in urban dwell, based on the renewal of historical forms of participation and articulation with local governance. These are groups that are sustained by memory and emotional plots, resolving emerging tensions in daily life. The conclusions and reflections raise the connective power of the aesthetic dimension, especially for the integration of the contradictions inherent to vital processes and the need to continue building a multiple space for the study of urban dwell.Presentamos resultados de una investigación que indagó sobre las formas colectivas urbanas en zonas consolidadas de la ciudad de Montevideo. Realizamos una serie de exploraciones de corte etnográfico, haciendo foco en situaciones sociales que implican a diversos colectivos. Nos involucramos con colectivos barriales que intervienen de forma creativa en el territorio urbano. Tomamos tres casos claves que implican nuevas estéticas en el habitar urbano, a partir de la renovación de formas históricas de participación y articulación con la gobernanza local. Se trata de colectivos que se sostienen desde la memoria y las tramas afectivas, resolviendo tensiones emergentes en la vida cotidiana. Las conclusiones y reflexiones plantean el poder conectivo de la dimensión estética, especialmente para la integración de las contradicciones propias de los procesos vitales y la necesidad de continuar construyendo un espacio múltiple para el estudio del habitar urbano.Peer Reviewe

TEORIA DE MÀQUINES. Segona avaluació parcial (Curs 2024-2025)

Resolved2024/20251r quadrimestr

El macizo montañoso de las Guillerías. Un espacio natural de gran valor ecosistémico, entre Barcelona y Girona

Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesPostprint (published version

Splinters

The Latin American city has exploded. As a consequence of this urbanity explosion, splinters emerge; logistics poles, precarious settlements, private urbanizations, are some of the typologies of the fragments released by the expansive wave on natural and rural territories. In Uruguay we are assisting to a “boom” in planning and execution of private urbanizations as a mechanism for city reproduction and a preferred way of living for the upper social strata. Regulatory flexibility, increasingly powerful developer groups and the absence of public debate are some of the keys to understanding the multiplication of this type of development. In this paper are marked some synthetic definition of the topic by analyzing the most evident urban and territorial processes associated with these kind of urbanization and their advance on relevant natural environments of the country. Finally, are proposed some alternatives for studying cumulative impacts with a prospective and integrative vision of natural resaqources, ecosystems and preexistencesLa ciudad latinoamericana ha estallado. Como consecuencia de esta explosión de urbanidad, emergen las esquirlas; polos logísticos, asentamientos precarios, urbanizaciones privadas, son algunas de las tipologías de los fragmentos liberados por la onda expansiva sobre territorios naturales y rurales. En Uruguay asistimos a un verdadero auge de proyecto y ejecución de urbanizaciones privadas como mecanismo de reproducción de ciudad y modo de habitar preferente para los estratos sociales altos. La flexibilización normativa, grupos desarrolladores cada vez más poderosos y la ausencia de debate público son algunas de las claves para entender la multiplicación de este tipo de desarrollos. Se realiza un encuadre sintético del tema analizando los procesos urbanos y territoriales más evidentes asociados a estos emprendimientos y su avance sobre entornos naturales relevantes del país. Finalmente se ensayan alternativas para el estudio de los impactos acumulativos con visión prospectiva e integradora de recursos naturales, ecosistemas y preexistencias.Peer Reviewe