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X-band Repeat-pass Coherence at Short Temporal Baselines for Crop Monitoring
No full textA one-year time series of X-band images acquired by TerraSAR-X, TanDEM-X and PAZ in the same orbit configuration over an agricultural area has been exploited to assess the potential of X-band repeat-pass coherence for crop monitoring. The combination of TerraSAR-X, TanDEM-X and PAZ allows working with temporal baselines of 4 and 7 days, i.e. shorter than the 11-day revisit time of the individual satellites. These short temporal baselines are less affected by temporal decorrelation and help increase the sensitivity of coherence to crop growth. The analysis is carried out for 30 different crop types by comparing series of coherence and backscatter at X-band with NDVI extracted from Sentinel-2. C-band coherence from Sentinel-1 is also analysed with the same dataset for comparison purposes. In addition, a new radar vegetation index for co-polar data, called coRVI, is defined and evaluated. During the phenological cycle of the crops, coherence decreases at the early stages, and it increases again after harvest, keeping high values out of the growing season. X-band coherences for baselines of 4 and 7 days show the strongest correlations with NDVI, especially for short crops. Regarding the use of coRVI, it outperforms the backscattering coefficient of individual channels. Moreover, coRVI is better correlated with NDVI than coherence for several crop types, hence providing complementary information. The main conclusion is that X-band repeat-pass coherence with short temporal baselines (4 or 7 days) could be a valuable tool for crop monitoring if an adequate acquisition plan were implemented routinely.This work was supported by the Spanish Ministry of Science and Innovation (State Agency of Research, AEI) and the European Funds for Regional Development under Project PID2020-117303GB-C22/AEI/10.13039/501100011033
Gold-Indium Electrocatalysts for the Selective Oxidation of Glycerol Coupled with CO2 Reduction
No full textGlycerol electrooxidation is a promising alternative to the oxygen evolution reaction in carbon dioxide electroreduction processes. It has the potential to both reduce the overall cell voltage and enable the commercialization of anodic oxidation products. Gold is a material that exhibits a high performance for glycerol oxidation but has a high manufacturing cost. In this work we have synthesized a gold indium alloy that exhibits enhanced electrocatalytically properties, as evidenced by a reduction in the glycerol oxidation onset potential by 210 mV while reducing the electrode cost by 28%. This electrocatalyst has been evaluated in a flow cell configuration coupled with the cathodic reduction of carbon dioxide, and high faradaic efficiencies up to 90% have been achieved for both the anodic and cathodic products.The authors gratefully acknowledge support through coordinated project CO2GLY (PID2022–138491OB-C33, PID2022–138491OB-C32, PID2022–138491OB-C31) funded by MICIU/AEI/10.13039/501100011033 and ERDF/EU. M.M. and M.A. are grateful to AGAUR-Generalitat de Catalunya for 2024 FI-1 00421 and 2021DI020 grants
Sulfide mineralogy of igneous basic rocks (ophites) from the external zone of the Betic Cordillera
No full textThe Triassic sedimentary rocks of the external zone of the Betic Cordillera in southern Spain host abundant igneous basic rocks (“ophites”) metamorphosed in the greenschist facies. Investigation based on high-resolution transmission electron microscopy (HRTEM) reveals magmatic sulfides intimately intergrown with primary silicates (pyroxene, plagioclase and olivine), consisting of pyrrhotite (FeS to Fe7S8; monoclinic C2/c polytype 4C) and pentlandite ((FeNi)9S8; cubic Fm3m), bounded by tetragonal I2d chalcopyrite (CuFeS2). Whole-rock and clinopyroxene geochemical data suggest that Fe–Ni–Cu sulfides crystallized from melt droplets segregated by immiscibility from transitional-alkaline magmas, after their fractional crystallization and volatile oversaturation within crustal conduits developed during intraplate rifting. In contrast, hydrothermal sulfides are pyrite (FeS2) and/or chalcopyrite associated with secondary silicates (chlorite, epidote, saussurite, prehnite, sericite and quartz). Porous pyrite (cubic Pa3) hosts nanodomains of pyrrhotite (monoclinic C2/c polytype 4C and orthorhombic Cmca polytype 11C) and orthorhombic Pnnm marcasite (FeS2), evidencing disulfide formation via coupled Fe loss and S addition in pyrrhotite due to reaction with high-fS2 and high-fO2 fluids at < 300 °C. Tetragonal I2d chalcopyrite replacing pyrite also preserves nanodomains of pyrrhotite as well as of pyrite marcasite, suggesting reaction of pre-existing Fe sulfides with Cu transported by low-temperature (∼ 200–100 °C) acidic-to-neutral fluids. Additionally, inclusions of sphalerite (ZnS), galena (PbS) and vaesite (NiS2) in pyrite and chalcopyrite spotlight metal remobilization during hydrothermal alteration, which is further confirmed by the crystallization of cobaltite coronas (CoAsS) around pyrite. Our new results contribute to the current debate of the full sequence of processes operating in ore-forming mafic systems.This research has been supported by the project PROYEXCEL_00705 “Metallogeny of Cobalt in the Betic Cordillera” (grant no. P21-00705), funded by the Consejería de Transformación Económica, Industria, Conocimiento y Universidades de la Junta de Andalucía. The article processing charges for this open-access publication were covered by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)
Superregular Matrices over Finite Fields
No full textA trivially zero minor of a matrix is a minor having all its terms in the Leibniz formula equal to zero. A matrix is superregular if all of its minors that are not trivially zero are nonzero. In the area of Coding Theory, superregular matrices over finite fields are connected with codes with optimum error correcting capabilities. There are two types of superregular matrices that yield two different types of codes. One has in all of its entries a nonzero element, and these are called full superregular matrices. The second interesting class of superregular matrices is formed by lower triangular Toeplitz matrices. In contrast to full superregular matrices, all general constructions of these matrices require very large field sizes. In this work, we investigate the construction of lower triangular Toeplitz superregular matrices over small finite prime fields. Instead of computing all possible minors, we study the structure of finite fields in order to reduce the possible nonzero minors. This allows us to restrict the huge number of possibilities that one needs to check and come up with novel constructions of superregular matrices over relatively small fields. Finally, we present concrete examples of lower triangular Toeplitz superregular matrices of sizes up to 10.The first author was supported by The Center for Research and Development in Mathematics and Applications (CIDMA) through the Portuguese Foundation for Science and Technology (FCT Fundação para a Ciência e Tecnologia) Multi-Annual Financing Program for R&D Units. The second and third listed authors are partially supported by the Spanish I+D+i project PID2022-142159OBI00 of the Ministerio de Ciencia e Innovación, I+D+i project CIAICO/2022/167 of the Generalitat Valenciana, and the I+D+i project VIGROB-287 of the Universitat d’Alacant
Accessibility, competitiveness and performance relationships: The mediating role of social innovation
No full textBased on stakeholder theory and resource-based view, the aim of this paper is to study whether accessibility and social innovation have positive influences on the competitive advantage and performance of hotel companies directly; and whether accessibility has a positive influence on competitive advantage and performance indirectly through social innovation. For this purpose, a structural equation model is applied, based on data from 259 hotels in the Valencian Community (Spain). The results indicate that the direct relationship between accessibility and revenue per available room (RevPAR, objective variable) is negative; and the direct relationship between accessibility and competitive advantage and performance (perceptual variable) is non-significant. However, when social innovation acts as a mediating variable between accessibility and competitive advantage, performance and RevPAR, all three mediations are positive. This study contributes by reflecting the importance of accessibility, not only from a social point of view, but also from a competitive and economic point of view, when social innovation mediates.This work was supported by the Regional Ministry of Innovation, Universities, Science and Digital Society, Valencian Region (Spain) (Grant no. CIAICO/2021/124)
The Contribution of Commercial Flights to the Global Emissions of Inorganic and Organic Pollutants
No full textThe aviation industry significantly contributes to global greenhouse gas (GHG) emissions, accounting for approximately 2–3% of total annual CO2 emissions, with high-altitude operations amplifying radiative forcing effects. This study quantitatively examines aviation’s contributions to global pollution compared to other transportation sectors, such as road and maritime, highlighting the substantial challenges in mitigating its environmental footprint. We focus on emissions of organic compounds, including polycyclic aromatic compounds and dioxins, and analyze key pollutants such as CO2, NOX, and ultrafine particles alongside the sector’s indirect effects. Our estimation indicates that dioxin emissions from commercial flights are negligible, at only 0.76 g annually; however, the sector’s broader impact on climate and air quality is significant. The analysis also evaluates current mitigation strategies, including the adoption of sustainable aviation fuels (SAFs), international initiatives like CORSIA, and advancements in aircraft technologies and operational efficiency. Despite these efforts, the projected growth in air traffic, estimated to increase annually by 5% over the next decade, underscores the urgent need for accelerated innovation and robust policy frameworks to achieve sustainable aviation. These findings emphasize the necessity of addressing aviation’s unique environmental challenges through international cooperation, technological advancements, and targeted climate actions
First Lego League Alicante 2025
No full textResumen de la competición de robótica FIRST LEGO League Alicante (FLL Alicante), organizada por la Universidad de Alicante, el sábado 15 de febrero de 2025
On the Automatic Recognition of Jeongganbo Music Notation: Dataset and Approach
No full textThe Jeongganbo notation, the first music representation system in East Asia capable of jointly expressing pitch and duration, has been extensively used—and still is—in the Korean music tradition since its inception in the 15th century. In this regard, there exists a plethora of music works that exclusively endure as physical sheets, which not only constitutes a heritage preservation challenge due to the inherent degradation of this format but also impedes the use of computational tools to study and exploit this music tradition. While the Optical Music Recognition (OMR) field, which represents the research area devoted to devising methods capable of automatically transcribing music sheets into digital formats, has addressed this issue in a number of music notations from the Western tradition, no previous research has considered the preservation of Jeonganbo scores. In this context, this work presents the following contributions: (i) the first data assortment of real Jeongganbo scores for OMR tasks; (ii) a collection of synthetic data generation and augmentation mechanisms to alleviate the scarcity of manual annotation; and (iii) a neural-based transcription scheme based on state-of-the-art OMR strategies specifically tailored to Jeongganbo scores. The experiments performed prove the validity of the approach—performance rates close to a 90% of success—and open new research avenues for under-resourced yet challenging music notations.This research was supported by the National R&D Program through the National Research Foundation of Korea (NRF) funded by the Korean Government (MSIT) (RS-2023-00252944, Korean Traditional Gagok Generation Using Deep Learning)
José Belda Domínguez (1890-1969) and the archaeology of Alicante: historiographical assessment of a controversial figure
No full textJosé Belda Domínguez (1890-1969), más conocido como el ‘padre Belda’, es una de las figuras más conocidas de la arqueología alicantina de mediados del siglo XX. Su trayectoria lo llevó a ocupar diversos puestos de responsabilidad, siendo la dirección del Museo Arqueológico Provincial de Alicante entre 1940 y 1958 su etapa de mayor actividad. Sin embargo, el proceder arqueológico de sus intervenciones, caracterizado por la clandestinidad y la impunidad de la que gozó, especialmente, durante el franquismo; y, entre otras cuestiones, su propia personalidad, lo convirtieron en una figura muy polémica. En el presente estudio analizamos, desde un punto de vista historiográfico, su trayectoria en Alicante a través de diferentes puntos de inflexión. El objetivo es aproximarnos a su figura, examinar las motivaciones que se escondían detrás de sus gestiones y establecer un balance crítico sobre su posición en la historia de la arqueología.José Belda Domínguez (1890-1969), better known as ‘Father Belda’, is one of the best recognised personalities in Alicante archaeology in the mid-20th century. His career led him to occupy different positions of responsibility, his most significant stage being the direction of the Provincial Archaeological Museum of Alicante between 1940 and 1958. However, his archaeological interventions, characterised by the clandestinity and impunity he enjoyed especially during the Franco regime and, among other things, his own personality, made him a very controversial figure. In this paper we analyse, from a historiographical point of view, his career in Alicante through different turning points. The aim is to approach to his figure, to examine the motivations behind his activities and to establish a critical balance of his position in the history of archaeology.Este estudio se ha realizado en el marco de los proyectos de investigación I+D+i ‘El fenómeno de las Exposiciones (1873, 1878, 1929) y su valor como foros de construcción y difusión de la arqueología en Europa’ (PID2021-126974NB-I00) y ‘Entre Ilici eIyyuh: vivir, producir y consumir en la Alta Edad Media (ss. V al X d.C.)’ (PID2023-152305NB-I00), financiados por el Ministerio de Ciencia, Innovación y Universidades del Gobierno de España