Resultados de investigación

In this investigation, the sol–gel method is employed along with a corrosion inhibitor to seal a plasma electrolytic oxidation (PEO) coating, aiming to improve the long-term corrosion resistance of the AZ31 Mg alloy. Following an initial screening of corrosion inhibitors, 8-hydroxyquinoline (8HQ) is incorporated into the hybrid PEO/sol–gel system using two methods: (i) post-treatment of the PEO layer through immersion in an inhibitor-containing solution; (ii) loading the inhibitor into the sol–gel precursor. The characterization includes scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), and water drop contact angle measurements. The rheological properties of the inhibitor-loaded sol–gel precursors are assessed by measuring flow curves. The corrosion processes are evaluated in a saline solution through electrochemical impedance spectroscopy (EIS) and immersion tests with unscratched and scratched specimens, respectively. The results demonstrate the successful incorporation of the inhibitor for both loading strategies. Regardless of the loading approach, systems containing 8HQ exhibit the most favourable long-term corrosion resistance.

El archivo contiene los datos recogidos al finalizar un ciclo de talleres de lectura fácil con adolescentes migrantes en la Biblioteca Municipal Iván de Vargas (Madrid) en mayo de 2024. Se recogieron en hojas impresas y se volcaron manualmente a una hoja de cálculo para su análisis. Los participantes totales fueron 13 personas. La encuesta muestra una valoración muy positiva, especialmente entre quienes leyeron en voz alta. Se destacaron como aspectos más valorados el trabajar en la biblioteca y con personas distintas a sus profesoras habituales - es decir, aspectos relacionados con la participación más que con el valor académico y formativo del taller. En cambio, quienes no leyeron en voz alta, respondieron menos preguntas, mostraron menor motivación y dieron una valoración menos positiva del taller. Datos adicionales sobre el contexto en el que se generaron los datos y su interpretación están disponibles en la respectiva publicación, titulada "La promoción de la lectura para adolescentes migrantes en un proyecto de aprendizaje y servicio: análisis y evaluación de la experiencia" y publicada en la revista RIBES (2025).

This study addresses the fundamentals of corrosion inhibition of AA2024 alloy by tannic acid (TA), a Cr-free and eco-friendly natural product. To this end, the AA2024 alloy was immersed in NaCl solution (50 mM) with different TA concentrations (0.1–10 mM) for 7 days. Surface (SEM, Raman, and SKPFM) and electrochemical analyses (EIS, PDP, and SVET) revealed mixed inhibition after 1 day of immersion in TA solution. Long-term immersion tests in TA solutions produced a tannate-rich oxide film on the surface. The films with low tannate content (formed in 0.1 and 1 mM TA) showed the highest stability and corrosion resistance.

Experimental data published in the article Is there direct photoentrainment in the goldfish liver? Wavelength-dependent regulation of clock genes and investigation of the Opsin 7 family, Journal of Comparative Physiology-A, 2024.

The objective of this work is to understand the plasma electrolytic oxidation (PEO) treatment and electrochemical behaviour of a Ti6Al4V alloy manufactured by a laser powder bed fusion additive manufacturing (AM) technique known as direct metal laser sintering (DMLS). Ca and P-containing coatings were produced with short time (<120 s) PEO treatments (also termed as Flash-PEO) obtaining 3–10 μm-thick coatings on both the AM alloy and a conventional counterpart. Subsequently, the electrochemical behaviour of the bare and treated alloys was assessed in a modified α-MEM solution via potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The fine α-lamellar microstructure of the AM alloy with small β-phase particles at the interlamellar spaces was seen to advance the onset of sparking promoting faster growth of PEO coating in comparison to the conventional alloy. Flash-PEO coatings enhanced the corrosion protection of both conventional and AM alloys, the thinnest (<3 μm) coatings providing up to three times greater protection. AM Ti6Al4V was found to be susceptible to localized crevice corrosion which could be assigned to the high grain boundary density. Flash-PEO treatments, even as short as 35 s, were sufficient to successfully prevent it.

The present work aims to provide corrosion performance data for an additively manufactured Ti6Al4V alloy in saline and polluted environments. The as-received additively manufactured material underwent heat treatment at 850 °C for 3 h to transform the acicular α’ microstructure into a lamellar α microstructure. Comparative corrosion assessments were conducted between the heat-treated substrates, the as-received condition, and a conventionally mill-annealed alloy. Potentiodynamic polarization experiments were carried out in saline (3.5 wt.% NaCl) and acid aqueous media ((NH4)2SO4 containing Harrison’s solution). The corrosion performance of additively manufactured substrates matched or surpassed that of the conventional alloy in Harrison’s solutions while remaining inferior in saline medium, despite forming a thicker passive film. Overall, the XY plane showed better corrosion performance, particularly after the elimination of the acicular α’ martensite by the applied heat treatment. The results also suggested that the presence of the coarse β phase was beneficial in 3.5 wt.% NaCl solution and detrimental in Harrison’s solutions, more so in acidified and fluorinated conditions.

Bioactive plasma electrolytic oxidation (PEO) coatings were developed on a wrought Mg0.5Zn0.2Ca alloy using a transparent electrolyte for easy maintenance and waste disposal, compared to a conventional suspension-based solution. Treatment times of 300, 600, and 900 s were evaluated for their effects on coating morphology, composition, and corrosion resistance. A short-time electrochemical impedance spectroscopy (EIS) screening was utilized to identify coatings with optimal corrosion protection. To assess the degradation rate and corrosion mechanisms, hydrogen evolution was monitored under pH-controlled quasi-in vivo conditions over extended immersion periods. Coating thickness increased by only 3% from 300 to 900 s of treatment (13 and 18 µm, respectively), with pore bands formed near the barrier layer at 900 s. The short-term EIS screening revealed that the coatings produced at 600 and 900 s were less protective and consistent than those at 300 s due to the presence of pore bands, which increased permeability. Hydrogen evolution measurements during 5 days of immersion at pH 7.4 indicated a tenfold higher degradation rate of the PEO-coated alloy compared to the bare substrate. Therefore, none of the PEO coatings provided effective corrosion protection after 24 h of immersion, which is attributed to crack formation at the PEO/corrosion products interface. This highlights the importance of crevices in the corrosion of Mg-Zn-Ca alloys. The presence of ZnO exacerbates the corrosion of magnesium in crevice areas.

Leveraging an array of search criteria including composers, singers, theatres, geographical territories, sources, and more, scholars can delve into the nuances of performance practices and historical contexts around Metastasio’s drammi per musica. Furthermore, the DIDONE Arias Database offers a treasure trove of individual arias extracted from these performances, providing a unique opportunity to explore the interplay of musical elements such as key, scoring, time signature, vocal range, and other parameters. Beyond its scholarly utility, the DIDONE Database invites users to embark on a journey of exploration and discovery, offering a dynamic platform where the scores of these historic arias can be visualised and explored within the broader context of 18th-century operatic tradition.