Tierra, fuego, agua y aire: la escultura en Raku

La incorporación al Espacio Europeo de Educación Superior, ha traído consigo cambios metodológicos docentes. Los departamentos de Escultura y Pintura de la Facultad de Bellas Artes no han querido ser ajenos a ellos y desde los mismos varios profesores hemos diseñado y llevado a cabo una actividad docente común centrada en los alumnos a través de la técnica del aprendizaje activo. Estudiantes de tercero, cuarto y quinto curso de licenciatura y grado han ejercitado diferentes competencias profesionales partiendo de un problema común propuesto: el diseño y construcción de un horno artesanal y la ideación y realización de esculturas cociéndolas en el mismo con la técnica del raku. El objetivo no era únicamente la resolución del problema sino que el alumno fuera capaz de adquirir y aplicar todo un conjunto de conocimientos tanto teóricos como prácticos de la disciplina convirtiéndose en protagonista de su propio aprendizaje. Los resultados se plasmaron posteriormente en la exposición de las obras y en la publicación del desarrollo del proceso en el campus virtualPeer Reviewe

Calculation of Raman optical activity spectra for vibrational analysis

By looking back on the history of Raman Optical Activity (ROA), the present article shows that the success of this analytical technique was for a long time hindered, paradoxically, by the deep level of detail and wealth of structural information it can provide. Basic principles of the underlying theory are discussed, to illustrate the technique's sensitivity due to its physical origins in the delicate response of molecular vibrations to electromagnetic properties. Following a short review of significant advances in the application of ROA by UK researchers, we dedicate two extensive sections to the technical and theoretical difficulties that were overcome to eventually provide predictive power to computational simulations in terms of ROA spectral calculation. In the last sections, we focus on a new modelling strategy that has been successful in coping with the dramatic impact of solvent effects on ROA analyses. This work emphasises the role of complementarity between experiment and theory for analysing the conformations and dynamics of biomolecules, so providing new perspectives for methodological improvements and molecular modelling development. For the latter, an example of a next-generation force-field for more accurate simulations and analysis of molecular behaviour is presented. By improving the accuracy of computational modelling, the analytical capabilities of ROA spectroscopy will be further developed so generating new insights into the complex behaviour of molecules

Taller de geofísica : geomagnetisme

El magnetisme i en particular el camp magnètic de la Terra s'ensenya als alumnes des de la primària fins al batxillerat en diferents moments i amb un aprofundiment progressiu. Aquest article pretén complementar l'estudi del camp magnètic al batxillerat amb una acti-vitat pràctica sobre una tempesta magnètica enregistrada a l'Observatori de l'Ebre. El treball consta d'una introducció als conceptes bàsics que permeten comprendre el camp geomagnètic, les tempestes magnètiques i l'enregistrament que se'n fa en un ob-servatori magnètic. L'objectiu final serà donar una mesura de l'activitat magnètica. La re-solució d'un qüestionari ajudarà a reforçar aquests conceptes i facilitarà la mesura dels índexs d'activitat magnètica

UHE tau neutrino flux regeneration while skimming the Earth

The detection of Earth-skimming tau neutrinos has turned into a very promising strategy for the observation of ultra-high energy cosmic neutrinos. The sensitivity of this channel crucially depends on the parameters of the propagation of the tau neutrinos through the terrestrial crust, which governs the flux of emerging tau leptons that can be detected. One of the characteristics of this propagation is the possibility of regeneration through multiple $\nu_\tau \leftrightarrow \tau$ conversions, which are often neglected in the standard picture. In this paper, we solve the transport equations governing the $\nu_\tau$ propagation and compare the flux of emerging tau leptons obtained allowing regeneration or not. We discuss the validity of the approximation of neglecting the $\nu_\tau$ regeneration using different scenarios for the neutrino-nucleon cross-sections and the tau energy losses.Comment: 8 pages, 8 figure

The Raman optical activity of β-D-xylose: where experiment and theory meet

Besides its applications in bioenergy and biosynthesis, β-D-xylose is a very simple monosaccharide that exhibits relatively high rigidity. As such, it provides the best basis to study the impact of different solvation shell radii on the computation of its Raman optical activity (ROA) spectrum. Indeed, this chiroptical spectroscopic technique provides exquisite sensitivity to stereochemistry, and benefits much from theoretical support for interpretation. Our simulation approach combines density functional theory (DFT) and molecular dynamics (MD) in order to efficiently account for the crucial hydration effects in the simulation of carbohydrates and their spectroscopic response predictions. Excellent agreement between the simulated spectrum and the experiment was obtained with a solvation radius of 10 Å. Vibrational bands have been resolved from the computed ROA data, and compared with previous results on different monosaccharides in order to identify specific structure–spectrum relationships and to investigate the effect of the solvation environment on the conformational dynamics of small sugars. From the comparison with ROA analytical results, a shortcoming of the classical force field used for the MD simulations has been identified and overcome, again highlighting the complementary role of experiment and theory in the structural characterisation of complex biomolecules. Indeed, due to unphysical puckering, a spurious ring conformation initially led to erroneous conformer ratios, which are used as weights for the averaging of the spectral average, and only by removing this contribution was near perfect comparison between theory and experiment achieved

Distinguishing epimers through raman optical activity

The Raman optical activity spectra of the epimers β-d-glucose and β-d-galactose, two monosaccharides of biological importance, have been calculated using molecular dynamics combined with a quantum mechanics/molecular mechanics approach. Good agreement between theoretical and experimental spectra is observed for both monosaccharides. Full band assignments have been carried out, which has not previously been possible for carbohydrate epimers. For the regions where the spectral features are opposite in sign, the differences in the vibrational modes have been noted and ascribed to the band sign changes