489 research outputs found
The Gondola for the Sunrise iii Balloon-Borne Solar Observatory
No full textPublisher Copyright: © The Author(s) 2025.Sunrise iii is a balloon-borne solar observatory dedicated to investigating the physics governing the magnetism and dynamics in the lower solar atmosphere. The observatory is designed to operate in the stratosphere, at heights around 36 km (above 99% of Earth’s atmosphere), to avoid image degradation due to turbulence in the Earth’s lower atmosphere, to gain access to the NUV wavelengths down to 309 nm, and to enable (when flown during summer solstice) observing the Sun uninterruptedly 24 hours/day. It is composed of a balloon gondola (equivalent to a spacecraft bus) carrying a 1-m aperture telescope (the largest solar telescope to-date to fly in the stratosphere on a balloon) feeding an imaging vector magnetograph and two spectropolarimeters aiming at acquiring high spatial resolution high cadence time series maps of the solar vector magnetic fields, plasma flows, and temperature in the photosphere and chromosphere. In July 2024 Sunrise iii successfully completed a six and a half days long stratospheric flight from Kiruna (Sweden) to Northern Canada at an average altitude of 36 km. This was the third successful flight of the Sunrise observatory, which had previously flown in 2009 and 2013. For this flight it was upgraded substantially with a new and improved suite of three instruments carried by a completely new gondola with upgraded pointing control system. This article focuses on describing the design and flight performance of the Sunrise iii gondola and all its subsystems. It describes the gondola mechanical structure, its power system, its command and control system, and in particular its pointing control system which was key for achieving high spatial and spectral resolution images of the solar photosphere and chromosphere by the three instruments.Peer reviewe
Solar house prototypes as living labs in architecture for holistic sustainability education
No full textThe LOW3 prototype solar house of UPC has been designed and built between 2008 and 2010 and converted and operated as a Living Lab for sustainable architecture and lifestyle since 2011 at the ETSAV campus at Sant Cugat del Vallés (Barcelona) under the responsibility of the author (www.livinglab-low3.blogspot.com)
This paper highlights the importance of Living Labs as innovation infrastructures in Higher Education and presents the specific educational experience of LOW3 within the institutional framework of UPC, drawing from 5 years of action research regarding pluridisciplinary, experience based sustainability education.Postprint (published version
Authors, languages and potential translations in Ibero-American cultural periodicals (1898-1959), with VIAF linked author data
No full textThe dataset provides data on contributors—authors of contributions/articles—to Ibero-American cultural periodicals from the first half of 20th century. Using basic information like article titles and authorship as a starting point, we have retrieved a set of 60987 potential authors to 292186 articles in 309 periodicals published between 1898 and 1959, held in online repositories or libraries located in Argentina, Spain, Portugal, and Germany, all related to Spanish-speaking and Lusophone literary and cultural magazines. By applying machine learning and natural language processing tools, as well as by linking the author's names against the Virtual International Authority File (VIAF), we provide enriched information on gender, language, and nationality for about 66% of the initially identified contributor names, responsible for about 26% of the articles. We identify potential translations—loosely defined as texts published in a language different from the author’s native or writing language—and the presence of foreign authors in the Ibero-American cultural press
Modelling the hidden magnetic field of low-mass stars
No full textPL acknowledges support from a Science and Technology Facilities Council studentship. JM, AAV and RF acknowledge support from fellowships of the Alexander von Humboldt foundation, the Royal Astronomical Society and Science and Technology Facilities Council, respectively.Zeeman-Doppler imaging is a spectropolarimetric technique that is used to map the large-scale surface magnetic fields of stars. These maps in turn are used to study the structure of the stars' coronae and winds. This method, however, misses any small-scale magnetic flux whose polarization signatures cancel out. Measurements of Zeeman broadening show that a large percentage of the surface magnetic flux may be neglected in this way. In this paper we assess the impact of this 'missing flux' on the predicted coronal structure and the possible rates of spin-down due to the stellar wind. To do this we create a model for the small-scale field and add this to the Zeeman-Doppler maps of the magnetic fields of a sample of 12 M dwarfs. We extrapolate this combined field and determine the structure of a hydrostatic, isothermal corona. The addition of small-scale surface field produces a carpet of low-lying magnetic loops that covers most of the surface, including the stellar equivalent of solar 'coronal holes' where the large-scale field is opened up by the stellar wind and hence would be X-ray dark. We show that the trend of the X-ray emission measure with rotation rate (the so-called 'activity-rotation relation') is unaffected by the addition of small-scale field, when scaled with respect to the large-scale field of each star. The addition of small-scale field increases the surface flux; however, the large-scale open flux that governs the loss of mass and angular momentum in the wind remains unaffected. We conclude that spin-down times and mass-loss rates calculated from surface magnetograms are unlikely to be significantly influenced by the neglect of small-scale field.Peer reviewe
Solar house prototypes as living labs in architecture for holistic sustainability education
No full textThe LOW3 prototype solar house of UPC has been designed and built between 2008 and 2010 and converted and operated as a Living Lab for sustainable architecture and lifestyle since 2011 at the ETSAV campus at Sant Cugat del Vallés (Barcelona) under the responsibility of the author (www.livinglab-low3.blogspot.com)
This paper highlights the importance of Living Labs as innovation infrastructures in Higher Education and presents the specific educational experience of LOW3 within the institutional framework of UPC, drawing from 5 years of action research regarding pluridisciplinary, experience based sustainability education
Solar house prototypes as living labs in architecture for holistic sustainability education
No full textThe LOW3 prototype solar house of UPC has been designed and built between 2008 and 2010 and converted and operated as a Living Lab for sustainable architecture and lifestyle since 2011 at the ETSAV campus at Sant Cugat del Vallés (Barcelona) under the responsibility of the author (www.livinglab-low3.blogspot.com)
This paper highlights the importance of Living Labs as innovation infrastructures in Higher Education and presents the specific educational experience of LOW3 within the institutional framework of UPC, drawing from 5 years of action research regarding pluridisciplinary, experience based sustainability education.Postprint (published version
Performance and Economic Comparison of Solar Cooling Configurations
No full textAbstractIn this paper a performance and economic comparison of solar cooling configurations using a new integrated approach combining the hourly thermal-optical performance assessment of the solar systems with the economic aspects has been conducted. Evacuated tube solar collectors with single effect LiBr absorption chiller and compact solar linear concentrating Fresnel collectors with single effect or medium temperature double effect LiBr absorption chiller have been taken into account. Considering that all the produced cold thermal energy could be delivered to a final user, the latter solar cooling configuration shows the possibility to have the Levelized Cost Of Cooling (LCOC) comparable with standard electric compression cooling. However, technology improvements and economy of scale are necessary in order to reduce solar field cost in the range 150-250 €/m2
Understanding the Influence of Shunts in the I-V Curves and Electroluminescence of Multijunction Solar Cells
No full textThe influence of shunts on multijunction solar cells cannot be directly extrapolated from their effect on single junction solar cells. It is shown that the rules of thumb for single junction solar cells can mislead to wrong diagnosis on multijunction solar cells when they are only partially shunted. In order to properly assess their performance, three dimensional simulations have been carried out using equivalent electrical circuits. In this work, we point out the differences between completely and partially shunted multijunction solar cells under different regimes and evaluate the use of I V curves and electroluminescence as valid tools to detect the existence of shunts. A straightforward application of this work is its use in reliability analysis, allowing an undoubtedly identification of shunts at both the solar cell manufacture and on-field operation
Carta que escribió Rodrigo de Albornoz al capitán Luis de León. Anales del Museo Nacional de Arqueología, Historia y Etnografía. Num. 20 Tomo III (1925) Cuarta Época (1922-1933)
No full text"Buscar la raíz de todo": Martí en la subasta Stewart
No full textThis is an analysis of José Martí\u27s chronicle of the auction of the Stewart collection in 1887. Through a close reading and a comparison with other chronicles of the author and other reports on the event, I show how Martí manipulates the information and performs a complex work with the form to make his chronicle a coherent whole: a reflection about the soul and about art, its trade and appreciation. In his chronicle, painting soothes the suffering soul, and the auction-the most degrading manifestation of the art market-endangers that relief. In opposition to the auction\u27s implications, Martí looks for a way to approach the work of art that does not put the market at the center of the narrative, but that does not ignore it either. At the same time, he proposes and puts in practice the appreciation of the work of art as a condition for its enjoyment.Este es un análisis de la crónica de José Martí sobre el remate de la colección Stewart en 1887. Por medio de una "close-reading" y la confrontación con otras crónicas del mismo autor y otros reportajes sobre el evento, muestro cómo Martí manipula la información y realiza un complejo trabajo formal para hacer de su crónica un todo coherente: una reflexión sobre el alma y sobre el arte, su comercio y su entendimiento. En su crónica, la pintura alivia al alma que sufre, y la subasta -la manifestación más degradante del mercado del arte- pone en peligro este alivio. Contra lo que implica la subasta, Martí busca formas de aproximarse a las obras que no hagan del mercado el centro organizador del relato, pero que tampoco lo ignoren. A la vez propone y pone en práctica el entendimiento de la obra de arte como condición para su disfrute
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