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Experimental and numerical study of CO dissolution in a heterogeneous Hele-Shaw cell
No full textWe investigate the convective instability resulting from the dissolution of
carbon dioxide (CO) into water in a heterogeneous Hele-Shaw cell
utilizing both experimental and numerical approaches. Experiments are conducted
in a Hele-Shaw cell with a variable gap width corresponding to a log-normally
distributed permeability of variance . Two mean gaps
(370 m and 500 m) with the same correlation lengths ( =
0.032 m and = 0.016 m) are considered. Experiments in homogeneous
cells with a constant gap are also performed. The CO partial pressure
() is varied between (0.12 bar) and (0.85 bar). The convective patterns are visualized using Bromocresol
green. The effect of the heterogeneity on the instability is analyzed through
its wavenumber, amplitude and growth rate. There is a good agreement between
the experimental and numerical results. Fingers appear more dispersive and
distorted in the heterogeneous media. Heterogeneous cases display a larger
instability amplitude, faster growth rate and smaller dimensionless wavenumber.
This reflects that heterogeneity accelerates the instability and the merging of
the fingers. A comparison of the autocorrelation function of the fingering
patterns and the permeability field shows that heterogeneity increases the
dimensionless correlation length of the fingering pattern, which slows down its
growth when its size becomes comparable to the heterogeneity.R.B., P.M., and J.J.H. acknowledge the H2020 MSCA ITN program under the Grant No. 956457 (COPERMIX). R.B. and J.J.H. acknowledge the support of the MICIU/AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR through the Grant No. CNS2023-144134 (ESFERA).Peer reviewe
Hydrogenation of HOCO and formation of interstellar CO2: a not so straightforward relation
No full text11 pages, 9 figures, 1 tableCarbon dioxide (CO) is one of the most important interstellar molecules. While it is considered that it forms on the surface of interstellar dust grains, the exact contribution of different chemical mechanisms is still poorly constrained. Traditionally it is deemed that the CO + OH reaction occurring on top of ices is the main reaction path for its formation. Recent investigations showed that in reality the reaction presents a more complex mechanism, requiring an additional H-Abstraction step. Building on our previous works, we carried out a detailed investigation of such H abstraction reactions with the hydrogen atom as a reactant for the abstraction reaction. We found an unconventional chemistry for this reaction, markedly depending on the isomeric form of the HOCO radical prior to reaction. The favoured reactions are t-HOCO + H CO + HO, c-HOCO + H CO + H, and t/c-HOCO + H c/t-HCOOH. We estimate bounds for the rate constants of the less favoured reaction channels, t-HOCO + H CO + H and c-HOCO + H CO + HO, to be approximately 10 s. However, these estimates should be interpreted cautiously due to the significant role of quantum tunnelling in these reactions and the complex electronic structure of the involved molecules, which complicates their study. Our findings underscore the need for detailed investigation into the chemistry of interstellar CO and pave the way for a re-evaluation of its primary formation mechanisms in the interstellar medium.GM acknowledges the support of the grant RYC2022-035442-I funded by MICIU/AEI/10.13039/501100011033 and ESF + . GM also received support from project 20245AT016 (Proyectos Intramu- rales CSIC). We acknowledge the computational resources provided by bwHPC and the German Research Foundation (DFG) through grant no INST 40/575-1 FUGG (JUSTUS 2 cluster), the DRAGO computer cluster managed by SGAI-CSIC, and the Galician Super- computing Center (CESGA). The supercomputer FinisTerrae III and its permanent data storage system have been funded by the Spanish Ministry of Science and Innovation, the Galician Government, and the European Regional Development Fund (ERDF). Early parts of this work (GM) were also funded by Japan Society for the Promotion of Science (JSPS International Fellow P22013, and Grant-in-aid 22F22013). JER acknowledges the support of the Horizon Europe Framework Programme (HORIZON) under the Marie Skłodowska- Curie grant agreement No 101149067, ‘ICE-CN’. NW and YA acknowledge the support by JSPSKAKENHI grant No. 20H05847. AI acknowledges the support by JSPS Grant-in-Aid for Scientific Research JP24K17107.Peer reviewe
El Calendario de la Historia de la Ciencia
No full textCon relatos que, en no pocas ocasiones, desbordan los límites de la imaginación, este calendario o diario científico brinda una asombrosa crónica para cada día del año —y alguno más—. Sus historias sorprenderán y deleitarán a cualquier lector, revelando el fascinante camino que nos ha traído hasta el siglo XXI. Páginas: 557
Intervienen:
El autor: Moncho Núñez
José Manuel Sánchez Ron, historiador de la ciencia y miembro de la Real Academia Española
Pampa García Molina, periodista científica y coordinadora del Science Media Centre de España (FECYT)
Pilar López García-Gallo, vicedirectora del área de Comunicación y Cultura Científica del Museo Nacional de Ciencias Naturales
Antonio Cuesta, director de Guadalmazán
Retransmisión:
https://www.youtube.com/live/3QKwNFZFOzw?si=hBdJqMv2JIdy10ou¿Por qué decimos que el arcoíris tiene siete colores? ¿Qué es la obsolescencia programada? ¿A quién debemos la invención de los números atómicos?
¿Cómo llegamos a saber que la galaxia de Andrómeda no pertenece a la Vía Láctea? ¿Cuál fue la mayor erupción volcánica jamás registrada? ¿En qué momento se consiguió una vacuna eficaz contra la tuberculosis? ¿Es posible que una criatura se haya extinguido dos veces? ¿Qué nación europea vivió un mes de febrero de 3o días?
El calendario de la historia de la ciencia es un volumen indispensable para personas ávidas de historia y ciencia; recopila hechos trascendentales, invenciones brillantes, descubrimientos notables y sucesos asombrosos que sellaron la relación entre el progreso científico, la tecnología y la sociedad. Todos ellos ocurrieron antes del siglo XXI, y ofrecen un fresco instructivo de nuestro pasado. En estas páginas, estudiantes, cien-tíficos, profesores, periodistas, divulgadores y todos los amantes del conocimiento hallarán inspiración y una fuente de saber y entretenimiento.N
La restauración de un baluarte de artillería de los Reyes Católicos construido entre 1492-1495 sobre un puente nazarí en la Puerta del Arrabal de la Alhambra (Granada, España)
No full textEste trabajo es el resultado de un contrato con el Patronato de la Alhambra, con los siguientes datos:
Contrato Agencia Estatal Consejo Superior de Investigaciones Científicas – Patronato de la Alhambra y Generalife, Junta de Andalucía.
Investigador principal: Dr. Antonio Orihuela Uzal.Coordinador responsable del equipo técnico para la Dirección Facultativa y Coordinación de Seguridad y Salud de la Obra de Restauración del Baluarte de la Puerta del Arrabal de la Alhambra (Expte.: CONTR 2021 694761).The bastion of the Puerta del Arrabal is one of the six that the Catholic Monarchs ordered to be built, after their taking possession of the Alhambra in 1492, to protect the gates and other strategic places of its walled enclosure. Due to their design, they are considered to be part of the ‘transitional’ military architecture, between the end of the Middle Ages and the beginning of the Modern Age, when the development of the fortification conceived for the use of firearms began. It is located on the stream that collects the surplus from the irrigation of the Acequia Real de la Alhambra and runs parallel to the Cuesta del Rey Chico, an artificial moat that separates the enclosure of the palatine city from the almunia of the Generalife. This conditions its design, as it has to ride over the stream to be able to dominate the path in three directions and it has a three-storey tower to be able to beat the lower orchard of the Generalife from the last one.
Its west façade faces the enclosure of the northern forest of the Alhambra, in a place that is difficult to access because the stream flows through a deep ravine. The fact that it was covered by ivy and thick trees has prevented over time from verifying that this entire sector was built on a large Nasrid bridge, with a previous hydraulic complex, totally unknown to historiography and preserved in good condition, which served to accelerate and economize the work in the years 1492-1495 and conditioned its design.
The conservation works have been carried out in 2022-2024, applying the criteria of scientific restoration, with moderate interventions, which have reversed several negative actions carried out during the twentieth century, maintaining all the relevant historical remains, as well as its character as an old buildingPeer reviewe
Impact of UHMW PEO on the ionic speciation and electrochemical properties of EMIC-AlCl3 gel electrolytes
No full textPolymer gel electrolytes based on EMIC-AlCl3 (1:1.5) and ultra-high molecular weight polyethylene oxide (UHMW PEO Mv =8 ×106 g mol 1) were synthesised with PEO concentrations of 2, 3.5, 5, 10 wt% without the use of auxiliary solvents, by melting the polymer into the electrolyte. This method produced elastic gels with progressively increasing elastic modulus. The speciation of the chloroaluminate anions in the gel electrolytes was characterized by NMR and Raman spectroscopy, revealing a decrease in Al2Cl7 and corresponding increase in AlCl4with rising PEO content. In particular, the gel with 10 wt% PEO showed no detectable Al2Cl7. Electrochemical activity of these gels was evaluated using two configurations: a platinum disc electrode and parallel planar aluminium foil electrode, the latter mimicking a practical electrochemical cell operating geometry. Surprisingly, all gels exhibited electrochemical activity, even in the absence of the Al2Cl7species. Increasing PEO concentration led to reduced current densities but enhanced coulombic efficiency. The study discusses the influence of the molecular weight of PEO on ionic speciation and electrochemical performance of the polymer gel electrolytes, providing insights into the interplay between polymer content, ionic speciation, and electrochemical behaviour. These findings contribute to the development of safer, more sustainable aluminium batteries.The authors wish to thank Paula Pereira Lázaro for her help recording FT-Raman spectra and the Centro de Química Orgánica (CENQUIOR-CSIC) NMR service for their professional advice. We acknowledge financial support from CSIC Project PIE 202360E035, and the Grant PID2023-149077OB-C33 funded by MICIU/AEI/10.13039/ 501100011033 and by FEDER, UE.Peer reviewe
Nicotine consumption trends in Spain determined by wastewater analysis during a 3-year monitoring by the ESAR-Net network
Full text linkShape model, reference system definition, and cartographic mapping standards for comet 67P/Churyumov-Gerasimenko - Stereo-photogrammetric analysis of Rosetta/OSIRIS image data
No full textPreusker, F. et al.--Full list of authors: Preusker, F.; Scholten, F.; Matz, K. -D.; Roatsch, T.; Willner, K.; Hviid, S. F.; Knollenberg, J.; Jorda, L.; Gutiérrez, P. J.; Kührt, E.; Mottola, S.; A'Hearn, M. F.; Thomas, N.; Sierks, H.; Barbieri, C.; Lamy, P.; Rodrigo, R.; Koschny, D.; Rickman, H.; Keller, H. U.; Agarwal, J.; Barucci, M. A.; Bertaux, J. -L.; Bertini, I.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Fornasier, S.; Fulle, M.; Groussin, O.; Güttler, C.; Ip, W. -H.; Kramm, J. R.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Lopez Moreno, J. J.; Marzari, F.; Michalik, H.; Naletto, G.; Oklay, N.; Tubiana, C.; Vincent, J. -B.We analyzed more than 200 OSIRIS NAC images with a pixel scale of 0.9-2.4 m/pixel of comet 67P/Churyumov-Gerasimenko (67P) that have been acquired from onboard the Rosetta spacecraft in August and September 2014 using stereo-photogrammetric methods (SPG). We derived improved spacecraft position and pointing data for the OSIRIS images and a high-resolution shape model that consists of about 16 million facets (2 m horizontal sampling) and a typical vertical accuracy at the decimeter scale. From this model, we derive a volume for the northern hemisphere of 9.35 km ± 0.1 km. With the assumption of a homogeneous density distribution and taking into account the current uncertainty of the position of the comet's center-of-mass, we extrapolated this value to an overall volume of 18.7 km± 1.2 km, and, with a current best estimate of 1.0 × 10 kg for the mass, we derive a bulk density of 535 kg/m± 35 kg/m. Furthermore, we used SPG methods to analyze the rotational elements of 67P. The rotational period for August and September 2014 was determined to be 12.4041 ± 0.0004 h. For the orientation of the rotational axis (z-axis of the body-fixed reference frame) we derived a precession model with a half-cone angle of 0.14°, a cone center position at 69.54°/64.11° (RA/Dec J2000 equatorial coordinates), and a precession period of 10.7 days. For the definition of zero longitude (x-axis orientation), we finally selected the boulder-like Cheops feature on the big lobe of 67P and fixed its spherical coordinates to 142.35° right-hand-rule eastern longitude and -0.28° latitude. This completes the definition of the new Cheops reference frame for 67P. Finally, we defined cartographic mapping standards for common use and combined analyses of scientific results that have been obtained not only within the OSIRIS team, but also within other groups of the Rosetta mission. © ESO, 2015.OSIRIS was built by a consortium of the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany, CISAS – University of Padova, Italy, the Laboratoire d’Astrophysique de Marseille, France, the Instituto de Astrofísica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Técnica Aeroespacial, Madrid, Spain, the Universidad Politéchnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut für Datentechnik und Kommunikationsnetze der Technischen Universität Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We finally thank Nat Bachman (JPL/NAIF) for his very helpful support in the preparation of SPICE planetary constants kernels and the consortium that developed the MeshLab processing system for making it freely available.Peer reviewe
Introducción. la puesta en valor de una correspondencia científica
No full textIntroducción del libro Cartas a un botánico: historia natural, farmacia y sociabilidad científica en la correspondencia de Carlos Pa
Splice-Switching Antisense Oligonucleotides Correct Phenylalanine Hydroxylase Exon 11 Skipping Defects and Rescue Enzyme Activity in Phenylketonuria
No full textThe PAH gene encodes the hepatic enzyme phenylalanine hydroxylase (PAH), and its deficiency, known as phenylketonuria (PKU), leads to neurotoxic high levels of phenylalanine. PAH exon 11 is weakly defined, and several missense and intronic variants identified in patients affect the splicing process. Recently, we identified a novel intron 11 splicing regulatory element where U1snRNP binds, participating in exon 11 definition. In this work, we describe the implementation of an antisense strategy targeting intron 11 sequences to correct the effect of PAH mis-splicing variants. We used an in vitro assay with minigenes and identified splice-switching antisense oligonucleotides (SSOs) that correct the exon skipping defect of PAH variants c.1199+17G>A, c.1199+20G>C, c.1144T>C, and c.1066-3C>T. To examine the functional rescue induced by the SSOs, we generated a hepatoma cell model with variant c.1199+17G>A using CRISPR/Cas9. The edited cell line reproduces the exon 11 skipping pattern observed from minigenes, leading to reduced PAH protein levels and activity. SSO transfection results in an increase in exon 11 inclusion and corrects PAH deficiency. Our results provide proof of concept of the potential therapeutic use of a single SSO for different exonic and intronic splicing variants causing PAH exon 11 skipping in PKU
Impact of the Coformer Carbon-Chain Length on the Properties of Haloperidol Pharmaceutical Salts
No full textHaloperidol (HAL) is a conventional antipsychotic drug with poor aqueous solubility, which is associated with a major risk of side effects. In this context, crystal engineering has provided an efficient approach for tuning the physicochemical properties of active pharmaceutical ingredients (APIs). However, there is a huge lack of knowledge about how coformer molecules impact the pharmaceutical properties of the multicomponent materials, with special attention to solubility and stability. To this purpose, five novel salts and three ionic cocrystals were synthesized using HAL and a series of closely related dicarboxylic acid counterions.
Mechanochemical strategies were applied for synthesis, while thermal, spectroscopic, and X-ray diffraction techniques were used for a complete characterization of the materials. By understanding the relationships between the crystal structures and the final properties, this research seeks to inform the rational design of HAL multicomponent drugs, providing a framework for improving the performance of not only HAL but also other APIs with similar challenges.This research publication has been funded by the projects GBRMat PID2023-151538NB-I00, PID2020-115637GB-I00 and PID2023-148453NB-I00, supported by MCIU/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. D.C.-L. and A.D.-M. acknowledge COST Action CA22107 - Bringing Experiment and Simulation Together in Crystal Structure Prediction (BEST-CSP)Peer reviewe