Centro Científico Tecnológico - San Juan

Obtaining transparent ferroelectric ceramics requires balancing electrical and optical properties, typically achieved through controlled doping. In this study, densified lead titanate (PT) ceramics doped with different concentrations of lanthanum (PLT18, PLT20, and PLT22) were synthesized and characterized structurally, dielectrically, and optically. All compositions crystallized in a tetragonal perovskite structure; with increasing lanthanum content, the Curie temperature decreased and the diffuseness exponent (γ) increased, indicating a progressively more diffuse transition. Despite these trends, the maximum permittivity remained high and the dielectric loss was generally low. Among the compositions studied, PLT20 defined an optimal window for combined electrical and optical performance: it attained ~ 40% transmittance at 650 nm while exhibiting reduced influence of ferroelectric domain activity under operating conditions and a minimal contribution from secondary phases relative to adjacent compositions. This combination yields stable dielectric behavior with moderate loss and supports reliable electro-optic functionality. Collectively, the structural, dielectric, and optical results for the PLT20 ceramic establish it as a practical composition for lead-based transparent ferroelectric components.

Extreme hydrometeorological events (EHEs) represent a growing challenge for central-northeastern Argentina, where climatic variability interacts with structural socio-economic inequalities to shape spatially differentiated patterns of vulnerability and risk. This study develops a subnational‑scale assessment that integrates physical hazard indicators with socio-economic, demographic, and environmental variables to evaluate vulnerability and multi-hazard risk to EHEs at both long-term and short-term timescales.Risk is evaluated at the subnational scale for 1991–2020 as the interaction between EHE hazards and regional vulnerability. Hazards are derived from ERA5 reanalysis data and examined both individually—distinguishing long-term hazards such as prolonged water excesses and deficits, and short-term hazards including heatwaves, intense precipitation, and flash droughts—and jointly through multi-hazard indices. Individual EHE hazards are evaluated based on their frequency, duration, and intensity. Vulnerability is conceptualized through exposure, sensitivity, and adaptive capacity, using census and geospatial information provided by national agencies. Exposure reflects the spatial overlap between population, crop yields, and critical infrastructure. Sensitivity captures demographic and socioeconomic fragility, as well as environmental susceptibility. Adaptive capacity encompasses healthcare, technological, and educational resources. Individual and multi-hazard risks are then computed by integrating standardized hazard indices with the vulnerability index.The region exhibits an overall medium level of vulnerability, but with significant spatial contrasts. Central Argentina—including part of the country’s core crop region, where population and economic activity are concentrated—shows medium‑to‑low vulnerability, driven by high exposure yet moderated by low sensitivity and high adaptive capacity. In contrast, central‑northern Argentina—characterized by limited agro‑industrial and technological development—exhibits high vulnerability due to elevated sensitivity and restricted adaptive capacity, despite comparatively lower exposure levels. These patterns reflect broader regional socio‑environmental inequalities, where structural deficits intensify climate impacts. Regarding EHE hazard risks in the study region, heatwaves and long-term extreme precipitation deficits emerge as the highest-ranking risks both locally and regionally, coinciding with elevated hazard levels in the northern and northwestern areas, where vulnerability is likewise greatest. Although the eastern and northeastern areas exhibit the highest hazard levels for intense precipitation and long-term precipitation excesses, the associated risk is moderated by their medium vulnerability. Flash drought risk remains low and spatially restricted. Multi-hazard analysis reveals that the long-term combined risk is the highest and most widespread, whereas the short-term multi-hazard risk is more localized but strongly dominated by heatwaves.This study provides an integrated framework for understanding subnational vulnerability and multi-hazard risk to EHEs in Argentina. The results show that the socio-environmental conditions act as amplifiers or attenuators of EHE hazards, shaping the resulting risk across the region. Moreover, the dominance of long-term multi-hazard risk indicates that prolonged climatic stresses can intensify the impacts of short-term extremes. These findings underscore the need for differentiated adaptation strategies: reducing exposure in the south through improved land‑use planning, infrastructure development, and climate‑resilient agricultural management, and strengthening adaptive capacity in the north through investments in health, education, and institutional systems. Despite limitations related to data availability and indicator selection, the results offer actionable insights for territorial planning and climate adaptation.

The MagNetZ (Magnetic Network on Zoom) webinar series stands as a cornerstone for geomagnetism research, hosting online seminars since the early 2020. Launched amid COVID-19 constraints, MagNetZ are convened by a team of scientists to give visibility to scientific work of both leading scientists and early career researchers, to foster virtual collaboration, overcoming geographical limits for students and professionals alike. It promotes open science sharing, with broad appeal evidenced by international viewership and institutional ties. The presentations typically began with a short talk, followed by interactive Q&A space, which are both recorded, post-edited and published on YouTube (https://www.youtube.com/@MagNetZ) in a continuously growing archive of recorded content. These webinars are also uploaded to the EarthRef.org Digital Archive (ERDA), development and maintained by the EarthRef.org Database Team and can be cited. Thus far, more than 80 webinars are available for viewing. MagNetZ also supports for national meetings, such as the UK-based annual Magnetic Interactions meeting, offering them the platform to view the recordings of three meetings so far. The webinars provide in-depth discussions on paleo- and rock-magnetism and geomagnetic modeling, with topics spanning from geo- and planetary magnetic field dynamics to mineral properties studies for paleoclimatic reconstructions, from paleomagnetic data for geodynamic applications to archaeomagnetism, and more. The core features of MagNetZ are to ensure accessibility for all genders, all career stages and geographical distributions, enhancing community networks, and serving as an educational hub for magnetic data in tectonics and climate studies. Its YouTube platform ensures enduring access, sparking collaborations and awareness.

Abstract. Soil moisture (SM) in the profile is the main reservoir of water available for vegetation. Therefore, monitoring SM during dry-down periods is crucial for understanding vegetation water status, among other applications. Datasets derived from Land Surface Models, such as the ERA5-Land dataset, provide SM estimates at different depths. The aim of this study was to evaluate the ability of ERA5-Land SM data to detect dry-down periods and to test whether its drying time scale aligns with field measurements at three sites in the Argentine Pampas. The analysis was carried out across the three standard soil layers used by ERA5-Land: layer 1 (L1, 0-7 cm), layer 2 (L2, 7-28 cm), and layer 3 (L3, 28-100 cm). First, the evaluation of the ERA5-Land SM data showed a moderate agreement with field data, although it exhibited a high overestimation (bias > |0.09| m3/m3) in the SM estimates. On the other hand, dry-down periods analysis indicated that ERA5-Land SM data was able to detect a similar number of dry-down periods and drying time scales as observed in the field for L1 and L2. In contrast, at L3, both the number of detected periods and the estimated drying time scale were lower. ERA5-Land SM data showed a consistent and expected pattern of faster drying in the shallower layers, demonstrating its potential for monitoring SM dynamics within the profile.

En este estudio, analizamos la participación política de las poblaciones de la Puna de Jujuy mediante su rol como soldados de la Guardia Nacional durante la convulsionada década de 1870. Se examinan eventos y contextos asociados a los procesos de militarización estatal, especialmente vinculados a la conformación de cuadrillas y montoneras, así como a comportamientos calificados de sediciosos, en el marco del levantamiento campesino-indígena por la tierra. La investigación se inscribe en el marco conceptual de la «ciudadanía armada» y evidencia formas locales de agencia y negociación, así como una inserción activa en las instituciones estatales.

Este trabajo explora la relación entre dos debates fundamentales en metafísica de la ciencia: el estatus ontológico de las leyes de la naturaleza y la naturaleza del espacio-tiempo. Sostenemos que una metafísica naturalista bien articulada debe considerar ambos temas en conjunto, dado su estrecho vínculo en la teorización científica. En este contexto, defendemos una tesis de mínima, según la cual estos debates no pueden tratarse de manera aislada sin comprometer la coherencia interna de una concepción metafísica, y una tesis de máxima, que postula que las posiciones filosóficas con cargas ontológicas similares en cada debate tienden a alinearse naturalmente. Examinamos el regularismo y el necesitarismo nomológico, por un lado, y el relacionalismo, el sustancialismo y el supersustancialismo del espacio-tiempo, por otro, mostrando que las estrategias argumentativas utilizadas en ambos casos exhiben patrones comparables. Para evaluar nuestra propuesta, analizamos algunos casos históricos que podrían parecer problemáticos para nuestras tesis. Finalmente, señalamos el alcance y las limitaciones de nuestro enfoque y sugerimos que ofrece una base conceptual fértil para futuras investigaciones en metafísica de la ciencia.