Una introducción a la literatura científica

We discuss the convenience of an early introduction of undergraduate students to the reading of scientific papers, mostly divulgative or historical. This can encourage them to deeper readings and to search and discover in the scientific writings new sources of learning and pleasure. The aim of this activity is twofold: mainly, to approach the students to bibliographical sources different from the traditional textbooks and, collaterally, to habituate them to get acquainted with scientific information in foreign languages (mostly English). In this manner, the students can get further knowlegde and they can also learn new points of view or different topics from those commonly discussed during a typical academic course

El CEAPAT como centro de referencia estatal

[Resumen] El CEAPAT es un Centro de Referencia del IMSERSO, Ministerio de Sanidad y Política Social. La visión del CEAPAT es servir de referencia y excelencia en accesibilidad y diseño para todos, productos de apoyo e interacción digital, en beneficio de una sociedad avanzada para todas las personas, con la colaboración e implicación de todos los agentes

Light diffraction through a feather

Se ha utilizado una pluma de ave para estudiar la difracción de la luz, tanto de forma cualitativa como cuantitativa. La medida experimental de la separación entre los puntos luminosos del patrón de difracción obtenido con un puntero láser ha permitido determinar el espaciado entre las barbas y entre las bárbulas de la pluma. Los resultados obtenidos muestran un acuerdo satisfactorio con los correspondientes a la estructura típica de una pluma. Los materiales empleados, los conceptos involucrados y los resultados experimentales convierten a esta experiencia en un excelente recurso didáctico para el estudio de la difracción, tanto en los primeros cursos universitarios como en los últimos cursos del Bachillerato.We have used a feather to study light diffraction, in a qualitative as well as in a quantitative manner. Experimental measurement of the separation between the bright spots obtained with a laser pointer allowed the determination of the space between feather's barbs and barbules. The results we have obtained agree satisfactorily with those corresponding to a typical feather. Due to the kind of materials, the related concepts and the experimental results, this activity becomes an excellent didactic resource suitable for studying diffraction, both in introductory undergraduate as well as in secondary school physics courses

La Prehistoria como vehículo para un viaje al pasado en Educación Infantil

El trabajo está centrado en el contexto educativo de una escuela infantil con niños y niñas de 4 años, aunque puede ser adaptado a toda la etapa de Educación Infantil. Su eje central son las ciencias sociales, a través de la prehistoria enseñamos a los niños las nociones espaciales y temporales, así como las características de la época prehistórica. El centro de interés es la prehistoria, para ello he desarrollado una unidad didáctica titulada “Miguelón” que consta de nueve sesiones mediante las cuales los niños aprenderán conocimiento sobre la prehistoria a través de distintas actividades. La unidad didáctica incluye una evaluación para constatar los conocimientos adquiridos. Además el trabajo se completa con el cuaderno del maestro y las fichas del alumno referidas a todas las actividades.Grado en Educación Infanti

Calculated energy loss of swift light ions in platinum and gold: importance of the target electronic excitation spectrum

Understanding and predicting the energy loss of swift ions in metals is important for many applications of charged particle beams, such as analysis and modification of materials, and recently for modelling metal nanoparticle radiosensitisation in ion beam cancer therapy. We have calculated the stopping power of the transition metals Pt and Au for protons and alpha particles in a wide energy range, using the dielectric formalism, which realistically accounts for the excitation spectrum of each metal through the Mermin Energy Loss Function - Generalised Oscillator Strength methodology. For each combination of projectile, energy and target, we have considered: (i) the equilibrium charge state of the projectile through the target, (ii) the energy-loss due to electron capture and loss processes, and (iii) the energy loss resulting from the polarisation of the projectile's electronic cloud due to the self-induced electric field. Our calculated stopping powers show a fairly good agreement with the available experimental data for platinum and gold, particularly the most recent ones around the stopping power maximum, which validates the methodology we have used to be further extended to other transition metals. For the materials studied (platinum and gold), two commonly used and different sources of the experimental excitation spectrum yield comparable calculated stopping powers and mean excitation energies, the latter being closer to the most recent data provided in a recent ICRU Report than to previous compilations. Despite the small differences in the sources of excitation spectra of these metals, they lead to practically the same stopping power results as far as they reproduce the main excitation features of the material and fulfil physically motivated sum rules.Comment: 7 pages, 2 figure

Angular and Energy Distributions of Electrons Produced in Arbitrary Biomaterials by Proton Impact

We present a simple method for obtaining reliable angular and energy distributions of electrons ejected from arbitrary condensed biomaterials by proton impact. Relying on a suitable description of the electronic excitation spectrum and a physically motivated relation between the ion and electron scattering angles, it yields cross sections in rather good agreement with experimental data in a broad range of ejection angles and energies, by only using as input the target composition and density. The versatility and simplicity of the method, which can be also extended to other charged particles, make it especially suited for obtaining ionization data for any complex biomaterial present in realistic cellular environments.The authors recognize the financial support from the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (Project No. FIS2010–17225). PdV acknowledges financial support from the European Union’s FP7-People Program (Marie Curie Actions) within the Initial Training Network No. 608163 "ARGENT". Support from the European COST Action MP1002 NanoIBCT is gratefully acknowledged

Excitation and ionisation cross-sections in condensed-phase biomaterials by electrons down to very low energy: application to liquid water and genetic building blocks

Electronic excitations and ionisations produced by electron impact are key processes in the radiation-induced damage mechanisms in materials of biological relevance, underlying important medical and technological applications, including radiotherapy, radiation protection in manned space missions and nanodevice fabrication techniques. However, experimentally measuring all the necessary electronic interaction cross-sections for every relevant material is an arduous task, so it is necessary having predictive models, sufficiently accurate yet easily implementable. In this work we present a model, based on the dielectric formalism, to provide reliable ionisation and excitation cross-sections for electron-impact on complex biomolecular media, considering their condensed-phase nature. We account for the indistinguishability and exchange between the primary beam and excited electrons, for the molecular electronic structure effects in the electron binding, as well as for low-energy corrections to the first Born approximation. The resulting approach yields total ionisation cross-sections, energy distributions of secondary electrons, and total electronic excitation cross-sections for condensed-phase biomaterials, once the electronic excitation spectrum is known, either from experiments or from a predictive model. The results of this methodology are compared with the available experimental data in water and DNA/RNA molecular building blocks, showing a very good agreement and a great predictive power in a wide range of electron incident energies, from the large values characteristic of electron beams down to excitation threshold. The proposed model constitutes a very useful procedure for computing the electronic interaction cross-sections for arbitrary biological materials in a wide range of electron incident energies.This work has received funding from the European Union's Horizon 2020 Research and Innovation programme under the Marie Sklodowska-Curie grant agreement no. 840752, from the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (Project no. PGC2018-096788-B-I00), from the Fundación Séneca (Project no. 19907/GERM/15) and from the Conselleria d'Educació, Investigació, Cultura i Esport de la Generalitat Valenciana (Project no. AICO/2019/070). PdV acknowledges further financial support provided by the Spanish Ministerio de Economía y Competitividad by means of a Juan de la Cierva postdoctoral fellowship (FJCI-2017-32233)

Calculated energy loss of swift light ions in platinum and gold: importance of the target electronic excitation spectrum

Understanding and predicting the energy loss of swift ions in metals is important for many applications of charged particle beams, such as analysis and modification of materials, and recently for modelling metal nanoparticle radiosensitisation in ion beam cancer therapy. We have calculated the stopping power of the transition metals Pt and Au for protons and alpha particles in a wide energy range, using the dielectric formalism, which realistically accounts for the excitation spectrum of each metal through the Mermin Energy Loss Function - Generalised Oscillator Strength methodology. For each combination of projectile, energy and target, we have considered: (i) the equilibrium charge state of the projectile through the target, (ii) the energy-loss due to electron capture and loss processes, and (iii) the energy loss resulting from the polarisation of the projectile's electronic cloud due to the self-induced electric field. Our calculated stopping powers show a fairly good agreement with the available experimental data for platinum and gold, particularly the most recent ones around the stopping power maximum, which validates the methodology we have used to be further extended to other transition metals. For the materials studied (platinum and gold), two commonly used and different sources of the experimental excitation spectrum yield comparable calculated stopping powers and mean excitation energies, the latter being closer to the most recent data provided in a recent ICRU Report than to previous compilations. Despite the small differences in the sources of excitation spectra of these metals, they lead to practically the same stopping power results as far as they reproduce the main excitation features of the material and fulfil physically motivated sum rules.We thank financial support from the European Union's Horizon 2020 Research and Innovation programme under the Marie Sklodowska-Curie grant agreement no. 840752, the Spanish Ministerio de Economía y Competitividad and the European Regional Development Fund (Project no. PGC2018-096788-B-I00), and the Fundación Séneca (Project no. 19907/GERM/15)

Simulation of the energy spectra of swift light ion beams after traversing cylindrical targets: a consistent interpretation of experimental data relevant for hadron therapy

We have performed detailed simulations of the energy spectra, recorded at several angles, of proton and helium ion beams after traversing thin cylindrical targets of different nature (liquid water and ethanol jets, as well as a solid aluminium wire), in order to reproduce a series of measurements intended to assess the stopping power of 0.3–2 MeV ions. The authors of these experiments derived values of the stopping power of liquid water (a quantity essential for the evaluation of radiation effects in materials, particularly for radiotherapy purposes) that are ~10% lower than what is expected from other measurements and theories. In our simulations, instead of treating the stopping power as an unknown free parameter to be determined, we use as input the electronic stopping power accurately calculated within the dielectric formalism. We take into account in the simulations the different interactions that each projectile can experience when moving through the target, such as electronic stopping, nuclear scattering or electron charge-exchange processes. The detailed geometry of the target is also accounted for. We find that our simulated energy distributions are in excellent agreement with the published measurements when the diameter of the cylindrical targets is slightly reduced, what is compatible with the potential evaporation of the liquid jets. On the basis of such an excellent agreement, we validate the accuracy of the model we use to calculate electronic excitation cross sections for ions in condensed matter in its range of applicability (particularly the electronic stopping power) needed for charged particle transport models, and we offer a consistent, but alternative, interpretation for these experiments on ion irradiation of cylindrical targets.Financial support was provided by the Spanish Ministerio de Economía y Competitividad, the Spanish Ministerio de Ciencia, Innovación y Universidades and the European Regional Development Fund (Projects No. FIS2014-58849-P and PGC2018-096788-B-I00), as well as by the Fundación Séneca - Agencia de Ciencia y Tecnología de la Región de Murcia (Project No. 19907/GERM/15). PdV also acknowledges financial support provided by the Alexander von Humboldt Stiftung/Foundation through a postdoctoral fellowship

Análisis estructural del edificio “La Llotgeta”

[ES] El presente Proyecto Final de Grado se centra en el análisis de las prestaciones estructurales del edificio “La Llotgeta”, concluyendo, para el nuevo uso que se le va a destinar y tras las actuaciones de rehabilitación que se van a llevar a cabo, si la capacidad portante del mismo es suficiente y proponiendo, en caso de ser necesario, las actuaciones de rehabilitación, refuerzo o sustitución de las partes estructurales afectadas que fuera perceptivas. Para ello y teniendo en cuenta que tratamos con un edificio datado en 1928 y que forma parte del conjunto histórico del Mercado Central de Valencia se realizará un análisis de los diferentes materiales que lo componen, determinando sus características mecánicas más relevantes para el cálculo y planteando soluciones estructurales de acuerdo con el nivel de conservación y respetando el entorno histórico en el que se enmarca el edificio.[EN] This Final of Career work consist in the structural analysis of the building “La Llotgeta”, concluding, for the new use that is going to have and taking in account the new compositicion that is going to have after his rehabilitation, if the actual structural system it is enough for support the new estate of structural loads or if required interventions for the consolidation, restoration or replacement in a extreme case. For this purpose and taking care that we are talking about a building dated on 1928 and is part of the historical set “Mercado Central de Valencia” will be performed an analysis of the different materials of construction establishing their most relevant mechanical characteristics for the calculation and proposing interventions.Boullosa Abril, SI. (2015). Análisis estructural del edificio “La Llotgeta”. http://hdl.handle.net/10251/56303.TFG