Interneuronas inhibitorias y neuronas de proyección en los núcleos sensitivos trigeminales: un modelo para el estudio de mecanismos inhibitorios en el dolor neuropático

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Anatomía, Histología y Neurociencia. Fecha de lectura: 7 de Abril de 2011

El recuerdo de los futuros profesores de secundaria sobre sus profesores de Biología y Geología en educación secundaria

Con este trabajo se pretende conocer si el recuerdo que poseen los egresados de diferentes carreras científicas sobre la actitud y la metodología que usaban sus profesores de Biología y Geología (ESO) ha podido influir en su elección de carrera. Contamos con una muestra de 40 alumnos del Máster de Formación del Profesorado de Secundaria de la Universidad de Extremadura (España) durante el curso académico 2010/2011. El análisis realizado nos indica que los licenciados en Biología y Ciencias Ambientales recuerdan aspectos más favorables sobre sus profesores de Biología y Geología de Educación Secundaria que los egresados de otras carreras científicas, manifestando de este modo cierta concordancia entre el recuerdo y la carrera realizada

Mechanical properties of Al2O3 inverse opals by means of nanoindentation

In order to understand the mechanical behaviour of Al2O3 inverse opals, nanoindentation techniques have been implemented in material layers with three different microstructures, in terms of hollow or polystyrene spheres, with Al2O3 shells of distinct wall thickness. Different indenter tip geometries as well as contact loading conditions have been used, in order to induce different stress field and fracture events to the layers. Field emission scanning electron microscopy and focused ion beam have been employed to understand accommodation of plastic deformation induced during the indentation process. Results show that materials with polystyrene spheres exhibit higher hardness and modulus under sharp indentation, and cracking resistance under spherical indentation. Furthermore, deformation is discerned to be mainly governed by the rotation of the microspheres. In the case of the inverse opals made of hollow spheres, the main deformation mechanisms activated under indentation are the rearrangement and densification of themPostprint (author's final draft

La marcha hacia las Cortes de Alcalá de 1348 : anotaciones a la conflictividad social en la Castilla de Alfonso XI

Las diversas fuentes narrativas referidas al reinado de Alfonso XI de Castilla permiten hablar, a primera vista, de grandes facilidades para reconstruir éste

Accurate Approximation of the Matrix Hyperbolic Cosine Using Bernoulli Polynomials

[EN] This paper presents three different alternatives to evaluate the matrix hyperbolic cosine using Bernoulli matrix polynomials, comparing them from the point of view of accuracy and computational complexity. The first two alternatives are derived from two different Bernoulli series expansions of the matrix hyperbolic cosine, while the third one is based on the approximation of the matrix exponential by means of Bernoulli matrix polynomials. We carry out an analysis of the absolute and relative forward errors incurred in the approximations, deriving corresponding suitable values for the matrix polynomial degree and the scaling factor to be used. Finally, we use a comprehensive matrix testbed to perform a thorough comparison of the alternative approximations, also taking into account other current state-of-the-art approaches. The most accurate and efficient options are identified as results.This research was supported by the Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia (PAID-11-21).Alonso Abalos, JM.; Ibáñez González, JJ.; Defez Candel, E.; Alvarruiz Bermejo, F. (2023). Accurate Approximation of the Matrix Hyperbolic Cosine Using Bernoulli Polynomials. Mathematics. 11(3):1-22. https://doi.org/10.3390/math1103052012211

Towards understanding the active sites for the ORR in N-doped carbon materials through fine-tuning of nitrogen functionalities: an experimental and computational approach

The design of advanced N-doped carbon materials towards oxygen reduction reaction (ORR) catalysis is only possible if the nature of the active sites is fully understood. There is an important piece of research seeking to overcome this challenge through experimental or theoretical results. However, the combination of both approaches is necessary to deepen the knowledge about this subject. This work presents excellent agreement between experimental results and computational models, which provides evidence of the nature of the most active sites in N-doped carbon materials. N-doped carbon materials have been experimentally obtained through double stage treatment of polyaniline in distinct atmospheres (both oxygen-containing and inert atmospheres) at different temperatures (800–1200 °C). According to temperature programmed desorption (TPD), Raman spectroscopy, N2-adsorption isotherms at −196 °C and X-ray photoelectron spectroscopy (XPS), this synthesis method results in the selective formation of nitrogen species, without significant changes in structural order or porosity. ORR catalytic tests evidence the highly efficient catalysis, with platinum-like performance in terms of the current density and onset potential, of N-doped carbon materials selectively containing graphitic-type nitrogen species. Computational chemistry, through DFT calculations, shows that edge-type graphitic nitrogen is more effective towards ORR catalysis than pyridinic, pyrrolic, pyridonic, oxidized and basal-type graphitic nitrogen species.The authors thank Ministerio de Ciencia, Innovación y Universidades and FEDER for financial support (Project RTI2018-095291-B-I00, ENE2017-90932-REDT and FIS2015-64222-C2-2-P). MMF acknowledges support from the Portuguese Foundation for Science and Technology (FCT), under the projects IF/00894/2015, and FCT Ref. UID/CTM/50011/2019 for CICECO - Aveiro Institute of Materials

Verification of a Synchronous Machine Model for Stator Ground Fault Simulation Through Measurements in a Large Generator

This paper presents a synchronous machine model designed to simulate internal ground faults along the stator windings. The purpose of this model is to help to set the 100 % stator ground fault protection based on the measurement of the third harmonic in the grounding resistor. The setting of the above protection is not easy, as the third harmonic in the generator depends on the operation point and the saturation of the machine. The main contribution of this paper is that the model has been validated through the measurements on a 106 MVA hydro-generator under no-faulty condition obtaining good results. The model has been also tested under faulty conditions obtaining coherent results