Kinematic and paleobathymetric evolution of the South Atlantic

The opening of the South Atlantic Ocean is one of the most extensively researched problems in plate kinematics. In recent years focus has shifted to the early stages of continental separation. General agreement exists about ocean opening being the result of the diachronous separation of two major plates, having involved a certain degree of intracontinental deformation. However, in order to achieve their best fits, most modern models assign most of this intracontinental deformation to narrow mobile belts between large, independently moving plate-like continental blocks, even though timings and motions along their boundaries are not well known. Aiming to step away from the very large uncertainty introduced by this approach, here we present a model of oceanic growth based on seafloor spreading data (fracture zone traces and magnetic anomaly identifications) as a context within which to interpret intracontinental tectonic motions. Our model results are illustrated by an animated tectonic reconstruction. Spreading started at 138 Ma, with movement along intracontinental accommodation zones leading to the assembly of South America by 123 Ma and Africa by 106 Ma. Our model also provides an explanation for the inception and evolution of the Malvinas plate and its connection with the formation of a LIP south of the Falkland-Agulhas Fracture Zone. Finally, we challenge the view of narrow deformation belts as the sole sites of stress accommodation and discuss the implications of our model in terms of the distribution of intracontinental strain. However, paleobathymetry (depth variations through time) also needs to be considered for a fuller understanding of the ocean’s evolution and development of its petroleum systems. At first order, this is controlled by plate tectonics, which determines changes in the geographical location of the lithosphere, along with thermal subsidence, which controls changes in its vertical level. Thermal subsidence is modelled by applying plate-cooling theory to a high-resolution seafloor age grid derived from the plate kinematic model. Then, this thermal surface is refined to account for other factors that affect bathymetry at smaller scales or amplitudes, both within the ocean and the continent-ocean transition zones. The results are a series of paleobathymetric reconstructions of the South Atlantic, which provide a fuller picture of its evolution from Cretaceous times to present

Plates, plumes and geological time: are we wrong about plume-push?

In setting out to better understand what drives plate movements, not only did Lucia Perez-Diaz, Graeme Eagles and Karin Sigloch cast doubt on the theory of plume-push – they also unearthed a potential error in the calibration of our geological timescal

Charge transfer mechanism in guanine-based self-assembled monolayers on a gold surface

In this work, we have theoretically determined the one-electron oxidation potentials and charge transfer mechanisms in complex systems based on a self-assembled monolayer of guanine molecules adsorbed on a gold surface through different organic linkers. Classical molecular dynamics simulations were carried out to sample the conformational space of both the neutral and the cationic species. Thus, the redox potentials were determined for the ensembles of geometries through multiscale quantum-mechanics/molecular-mechanics/continuum solvation model calculations in the framework of the Marcus theory and in combination with an additive scheme previously developed. In this context, conformational sampling, description of the environment, and effects caused by the linker have been considered. Applying this methodology, we unravel the phenomena of electric current transport by evaluating the different stages in which charge transfer could occur. The results revealed how the positive charge migrates from the organic layer to the gold surface. Specifically, the transport mechanism seems to take place mainly along a single ligand and driven with the help of the electrostatic interactions of the surrounding molecules. Aside, several self-assembled monolayers with different linkers have been analyzed to understand how the nature of that moiety can tune the redox properties and the efficiency of the transport. We have found that the conjugation between the guanine and the linker, at the same time conjugated to the gold surface, gives rise to a more efficient transport. In conclusion, the established computational protocol sheds light on the mechanism behind charge transport in electrochemical DNA-based biosensor nanodevicesPID2022-138470NB-I00, PID2020-117806GA-I00, CNS2022-13572

Modelling one-electron oxidation potentials and hole delocalization in double-stranded DNA by multilayer and dynamic approaches

The number of innovative applications for DNA nowadays is growingquickly. Its use as a nanowire or electrochemical biosensor leads to the need for a deepunderstanding of the charge-transfer process along the strand, as well as its redoxproperties. These features are computationally simulated and analyzed in detailthroughout this work by combining molecular dynamics, multilayer schemes, and theMarcus theory. One-electron oxidation potential and hole delocalization have beenanalyzed for six DNA double strands that cover all possible binary combinations ofnucleotides. The results have revealed that the one-electron oxidation potentialdecreases with respect to the single-stranded DNA, giving evidence that the greaterrigidity of a double helix induces an increase in the capacity of storing the positivecharge generated upon oxidation. In addition, the hole is mainly stored in nucleobaseswith large reducer character, i.e., purines, especially when those are arranged in astacked configuration in the same strand. From the computational point of view, thesampling needed to describe biological systems implies a significant computational cost. Here, we show that a small number ofrepresentative conformations generated by clustering analysis provides accurate results when compared with those obtained fromsampling, reducing considerably the computational costThis work was partially supported by the MICINN−Spanish Ministry of Science and Innovation Projects PID2022-138470NB-I00 and PID2020-117806GA-I00 funded by MCIN/AEI/10.13039/ 501100011033, and the “María de Maeztu” (CEX2018000805-M) Program for Centers of Excellence in R&D. J.J.N. acknowledge the Comunidad de Madrid for funding through the Attraction of Talent Program (grant reference 2022-5A/BMD-24244). J.L.T. acknowledges the FPU19/ 02292 grant from the Spanish Ministry of University. Additionall

Positioning Control System for a Large Range 2D Platform with Submicrometre Accuracy for Metrological and Manufacturing Applications

The importance of nanotechnology in the world of Science and Technology has rapidly increased over recent decades, demanding positioning systems capable of providing accurate positioning in large working ranges. In this line of research, a nanopositioning platform, the NanoPla, has been developed at the University of Zaragoza. The NanoPla has a large working range of 50 mm × 50 mm and submicrometre accuracy. The NanoPla actuators are four Halbach linear motors and it implements planar motion. In addition, a 2D plane mirror laser interferometer system works as positioning sensor. One of the targets of the NanoPla is to implement commercial devices when possible. Therefore, a commercial control hardware designed for generic three phase motors has been selected to control and drive the Halbach linear motors.This thesis develops 2D positioning control strategy for large range accurate positioning systems and implements it in the NanoPla. The developed control system coordinates the performance of the four Halbach linear motors and integrates the 2D laser system positioning feedback. In order to improve the positioning accuracy, a self calibration procedure for the characterisation of the geometrical errors of the 2D laser system is proposed. The contributors to the final NanoPla positioning errors are analysed and the final positioning uncertainty (k=2) of the 2D control system is calculated to be ±0.5 µm. The resultant uncertainty is much lower than the NanoPla required positioning accuracy, broadening its applicability scope.<br /

2D positioning control system for the planar motion of a nanopositioning platform

A novel nanopositioning platform (referred as NanoPla) in development has been designed to achieve nanometre resolution in a large working range of 50 mm × 50 mm. Two-dimensional (2D) movement is performed by four custom-made Halbach linear motors, and a 2D laser system provides positioning feedback, while the moving part of the platform is levitating and unguided. For control hardware, this work proposes the use of a commercial generic solution, in contrast to other systems where the control hardware and software are specifically designed for that purpose. In a previous paper based on this research, the control system of one linear motor implemented in selected commercial hardware was presented. In this study, the developed control system is extended to the four motors of the nanopositioning platform to generate 2D planar movement in the whole working range of the nanopositioning platform. In addition, the positioning uncertainty of the control system is assessed. The obtained results satisfy the working requirements of the NanoPla, achieving a positioning uncertainty of ±0.5 µm along the whole working range

Positioning uncertainty of the control system for the planar motion of a nanopositioning platform

The novel nanopositioning platform (NanoPla) that is in development at the University of Zaragoza has been designed to achieve nanometre resolution in a large working range of 50 mm × 50 mm. The 2D movement is performed by four custom-made Halbach linear motors and a 2D laser system provides positioning feedback, while the moving part of the platform is levitating and unguided. As control hardware, this work proposes the use of a commercial solution, in contrast to other systems, where the control hardware and software were specifically designed for the purpose. In a previous work of this research, the control system of one linear motor implemented in the selected commercial hardware was presented. In this study, the developed control system is extended to the four motors of the nanopositioning platform to generate a 2D planar movement in the whole working range of the nanopositioning platform. In addition, the positioning uncertainty of the control system is assessed. The obtained results satisfy the working requirements of the NanoPla, achieving a positioning uncertainty of ±0.5 µm along the whole working range

Mejora educativa mediante un foro de apoyo en competencias digitales para las familias del alumnado

El presente documento comprende un trabajo de fin de Máster en formación del profesorado (especialidad de Tecnología e Informática), en el que se recoge la propuesta de intervención en forma de proyecto de innovación que procura hacer frente a algunas de las necesidades ya existentes pero mayormente evidenciadas durante la pandemia COVID-19, como son la falta de competencias digitales del alumnado y las familias, hasta podríamos decir que en algunos casos de los docentes, convirtiéndose en una solución y a la vez una obligación el uso de las Tecnologías de la Información y la Comunicación (TIC) para la interacción y seguimiento del progreso en la evolución educativa. Por otro lado, es evidente la necesidad de trabajar las competencias blandas en el alumnado a la vez que enseñamos los contenidos más concretos, es decir formamos en competencias; a la par que obligatoria según la legislación actual. Por último, aunque no único como factor de éxito, no se puede negar la importancia del soporte familiar en los resultados académicos, por lo que en esta ideación se acerca a las familias a la vida educativa, siendo habitualmente baja la implicación de estas en los centros educativos y con escasa visión de los contenidos que se trabajan. En resumen, este proyecto pretende, integrando los contenidos curriculares en una Unidad Didáctica, aunar esfuerzos en estas problemáticas y medir los resultados; para ello se apoya en una herramienta TIC como es un foro digital colaborativo, el cual estará a disposición de las familias para la resolución de dudas e incidencias en cuanto a problemas de Hardware y Software de usuario, haciendo además uso del Aprendizaje Servicio para aumentar la motivación intrínseca en el aprendizaje. Se ha contextualizado en el aula de Bachillerato, curso 1º, asignatura Tecnologías de la Información y Comunicación.<br /

Implementación del proyecto en red de aprendizaje y servicio human technology en el currículo de bachillerato a través del aprendizaje basado en proyectos

El proyecto en red human technology es un proyecto ya consolidado de aprendizaje y servicio (ApS) que consiste en la colaboración de los departamentos de electrónica e informática de formación profesional del instituto de educación secundaria Pablo Serrano con centros de educación especial (E.E.) de Aragón en cuatro puntos: mantenimiento de equipos electrónicos específicos de los centros de E.E., realización de adaptaciones para que equipos comerciales puedan ser utilizados por alumnado de E.E., desarrollo de aplicaciones informáticas y, por último, fabricación de equipos electrónicos originales que sean útiles para el alumnado y profesorado de E.E. (IES Pablo Serrano, 2019). El fundamento principal de este trabajo es implementar, a través de este último punto de fabricación de equipos electrónicos, el proyecto de ApS human technology en el currículo de la asignatura de tecnología industrial I de bachillerato a partir de la metodología del aprendizaje basado en proyectos. Esta metodología pone el foco en el proceso de enseñanza aprendizaje y obtención de conocimientos frente al resultado final. El alumnado, de manera colaborativa, trabaja en el descubrimiento de los conocimientos y herramientas necesarias para lograr el producto deseado con la guía del docente. Todo ello se ha integrado en el proyecto en red de ApS Human Technology, aportando al proceso de enseñanza aprendizaje el valor añadido de servicio a la comunidad y motivando al alumnado en la consecución de unos objetivos que ayuden a mejorar su entorno. <br /