KIC 9821622: An interesting lithium-rich giant in the Kepler field

We report the discovery of a new exceptional young lithium-rich giant, KIC 9821622, in the \textit{Kepler} field that exhibits an unusually large enhancement of $\alpha$, Fe-peak, and \textit{r}-process elements. From high-resolution spectra obtained with GRACES at Gemini North, we derived fundamental parameters and detailed chemical abundances of 23 elements from equivalent widths and synthesis analysis. By combining atmospheric stellar parameters with available asteroseismic data, we obtained the stellar mass, radius, and age. The data analysis reveals that KIC 9821622 is a Li-rich (A(Li)$_{NLTE}$ = 1.80 $\pm$ 0.2) intermediate-mass giant star ($M$ = 1.64 $M_{\odot}$) located at the red giant branch near the luminosity bump. We find unexpectedly elevated abundances of Fe-peak and \textit{r}-process elements. In addition, as previously reported, we find that this is a young star (2.37 Gyr) with unusually high abundances of $\alpha$-elements ([$\alpha$/Fe] = 0.31). The evolutionary status of KIC 9821622 suggests that its Li-rich nature is the result of internal fresh Li that is synthesized through the Cameron-Fowler mechanism near the luminosity bump. However, its peculiar enhancement of $\alpha$, Fe-peak, and \textit{r}-process elements opens the possibility of external contamination by material enriched by a supernova explosion. Although it is less likely, planet accretion cannot be ruled out.Comment: Letter, 6 pages, 3 figures, Accepted for publication in A&A. - Some language editing include

Modeling dust emission in PN IC 418

We investigated the infrared (IR) dust emission from PN IC 418, using a detailed model controlled by a previous determination of the stellar properties and the characteristics of the photoionized nebula, keeping as free parameters the dust types, amounts and distributions relative to the distance of the central star. The model includes the ionized region and the neutral region beyond the recombination front (Photodissociation region, or PDR), where the [OI] and [CII] IR lines are formed. We succeeded in reproducing the observed infrared emission from 2 to 200~\mm. The global energy budget is fitted by summing up contributions from big grains of amorphous carbon located in the neutral region and small graphite grains located in the ionized region (closer to the central star). Two emission features seen at 11.5 and 30~\mm are also reproduced by assuming them to be due to silicon carbide (SiC) and magnesium and iron sulfides (Mg$_x$Fe$_{1-x}$S), respectively. For this, we needed to consider ellipsoidal shapes for the grains to reproduce the wavelength distribution of the features. Some elements are depleted in the gaseous phase: Mg, Si, and S have sub-solar abundances (-0.5 dex below solar by mass), while the abundance of C+N+O+Ne by mass is close to solar. Adding the abundances of the elements present in the dusty and gaseous forms leads to values closer to but not higher than solar, confirming that the identification of the feature carriers is plausible. Iron is strongly depleted (3 dex below solar) and the small amount present in dust in our model is far from being enough to recover the solar value. A remaining feature is found as a residue of the fitting process, between 12 and 25~\mm, for which we do not have identification.Comment: Accepted for publication in Astronomy & Astrophysics. V2: adding reference

Spinor calculus on 5-dimensional spacetimes

Penrose's spinor calculus of 4-dimensional Lorentzian geometry is extended to the case of 5-dimensional Lorentzian geometry. Such fruitful ideas in Penrose's spinor calculus as the spin covariant derivative, the curvature spinors or the definition of the spin coefficients on a spin frame can be carried over to the spinor calculus in 5-dimensional Lorentzian geometry. The algebraic and differential properties of the curvature spinors are studied in detail and as an application we extend the well-known 4-dimensional Newman-Penrose formalism to a 5-dimensional spacetime.Comment: Convention mismatch and minor typos fixed. To appear in Journal of Mathematical Physic

Adaptación de la metodología al Espacio Europeo de Educación Superior. Análisis de la opinión de los alumnos

Tradicionalmente la asignatura “Métodos Cuantitativos para la Economía y la Empresa” seguía una metodología basada en la conocida lección magistral y con un temido examen final como única evaluación. Con el objetivo de adaptar dicha metodología al Espacio Europeo de Educación Superior, se han propuesto prácticas que faciliten el proceso de autoaprendizaje así como un nuevo sistema de evaluación continuo. El presente trabajo se centra en el análisis de la opinión del alumno, recogida mediante una encuesta, sobre la nueva metodología y los materiales elaborados

Quaternary glacial evolution in the Central Cantabrian Mountains (Northern Spain)

Peer reviewedPostprin

L’aprenentatge dels recursos didàctics del segle XXI: l’art contemporani

XVIII Jornades de Foment de la Investigació de la Facultat de Ciències Humanes i Socials (Any 2013)Aquest treball es contextualitza en la Facultat de Ciències de l’Educació de la Universitat de Lleida, en el marc d’un Programa d’intercanvi SICUE amb la Universitat Jaume I de Castelló de dos alumnes del Grau en Educació Primària. El marc del treball és l’assignatura «Pràctiques II», matèria de tercer curs del grau. L’objecte d’aquest estudi és analitzar el procés de generació de coneixement i aprenentatge mitjançant el treball a partir d’una obra d’art. Aquest procés comença amb la visita d’una exposició d’un Centre d’Art Contemporani de la ciutat de Lleida, on l’alumnat d’educació primària observa i gaudeix de l’obra. El treball posterior es realitza a l’escola, on aquestos es reuneixen setmanalment en grups d’internivells. Aquest és un espai on diferents grups heterogenis treballen de manera transdiciplinar. Per tant, totes les àrees del currículum tenen cabuda sense perdre de vista la pròpia llengua. Cada grup d'alumnes segueix el seu propi camí d’aprenentatge, però el coneixement es crea a partir del punt de partida comú: una obra d’art. El caràcter innovador d’aquest treball es basa en compartir amb la comunitat educativa l’aprenentatge, com a futurs docents, d’una metodologia basada en l’ensenyament, l’aprenentatge i la comunicació a través de l’art contemporani. Les seves bondats són degudes a la seva transversalitat, que permet el desenvolupament de competències necessàries per accedir al currículum

El estudio de las raíces inmigrantes en el aula. Una experiencia en la información de graduados en Educación Primaria

XVIII Jornades de Foment de la Investigació de la Facultat de Ciències Humanes i Socials (Any 2013)Este trabajo tiene como punto de partida la Facultad de Ciencias de la Educación de la Universidad de Lleida (UdL), dentro del programa de intercambio interuniversitario SICUE con la Universidad Jaume I de Castellón (UJI) con dos alumnos del grado en Educación Primaria. El marco del trabajo es definido por la asignatura “Didáctica de las Ciencias Sociales – Historia General de Europa”, materia obligatoria de tercer curso. El objeto de estudio ha sido el diseño y posterior implementación de una secuencia didáctica para tratar la problemática de la inmigración en las aulas. La propuesta se basa en la propia experiencia del alumnado i aprovecha la reflexión crítica sobre el uso de este término que hace la satírica serie norteamericana The Simpsons (7x23 [capítulo 23, temporada 7]). El principal objetivo de la secuencia es romper los prejuicios que existen alrededor del concepto de inmigrante y poder construir una nueva visión más concreta y objetiva a partir del análisis crítico del capítulo y de una serie de actividades que se derivan. Las actividades se han llevado a cabo con alumnado de Tercer Ciclo de Educación Primaria, pero se considera que también podrían ser de interés para alumnos de Primer Ciclo de Educación Secundaria Obligatoria (ESO). El carácter innovador de este trabajo consiste en evidenciar las diferencias entre el proceso de conceptualización de la secuencia didáctica y el de su implementación. Se pretende, por tanto, contrastar ambas vertientes, teórica y práctica, y mostrar a la comunidad académica los resultados y las conclusiones de este doble proceso formativo, como docentes y discentes del alumnado del Grado en Educación Primaria

Imposing virtual origins on the velocity components in direct numerical simulations

The relative wall-normal displacement of the origin perceived by different components of near-wall turbulence is known to produce a change in drag. This effect is produced for instance by drag-reducing surfaces of small texture size like riblets and superhydrophobic surfaces. To facilitate the research on how these displacements alter near-wall turbulence, this paper studies different strategies to model such displacement effect through manipulated boundary conditions. Previous research has considered the effect of offsetting the virtual origins perceived by the tangential components of the velocity from the reference, boundary plane, where the wall-normal velocity was set to zero. These virtual origins are typically characterised by slip-length coefficients in Robin, slip-like boundary conditions. In this paper, we extend this idea and explore several techniques to define and implement virtual origins for all three velocity components on direct numerical simulations (DNSs) of channel flows, with special emphasis on the wall-normal velocity. The aim of this work is to provide a suitable foundation to extend the existing understanding on how these virtual origins affect the near-wall turbulence, and ultimately aid in the formulation of simplified models that capture the effect of complex surfaces on the overlying flow and on drag, without the need to resolve fully the turbulence and the surface texture. From the techniques tested, Robin boundary conditions for all three velocities are found to be the most satisfactory method to impose virtual origins, relating the velocity components to their respective wall-normal gradients linearly. Our results suggest that the effect of virtual origins on the flow, and hence the change in drag that they produce, can be reduced to an offset between the virtual origin perceived by the mean flow and that perceived by the overlying turbulence, and that turbulence remains otherwise smooth-wall-like, as proposed by Luchini (1996). The origin for turbulence, however, would not be set by the spanwise virtual origin alone, but by a combination of the spanwise and wall-normal origins. These observations suggest the need for an extension of Luchini’s virtual-origin theory to predict the change in drag, accounting for the wall-normal transpiration when its effect is not negligible

Distribución vertical de la macrofauna en sedimentos contaminados del interior del puerto de Ceuta

Se ha estudiado la distribución vertical de la macrofauna y su relación con las variables fisicoquímicas de los sedimentos contaminados del puerto de Ceuta. La obtención de las muestras se llevó a cabo mediante buceo con escafandra autónoma y empleando instrumentos de muestreo tipo core (10 cm × 17 cm × 35 cm), diferenciándose las siguientes profundidades en la columna de sedimento: 0-2 cm, 2-5 cm, 5-10 cm y más de 10 cm. Los crustáceos Pariambus typicus Kröyer, 1844; Apseudes latreilli Milne-Edwards, 1820; Corophium runcicorne Della Valle, 1893; C. sextonae Crawford, 1937; el molusco Parvicardium exiguum (Gmelin, 1791) y los poliquetos Pseudomalacoceros tridentata (Southern, 1914) y Exogone verrugera Cleparede, 1868 se localizaron en los dos primeros centímetros de sedimento, mientras que el molusco Loripes lacteus (L., 1758) y los poliquetos Platynereis dumerilii Audouin y Milne-Edwards, 1833; Cirratulus cirratus (Muller, 1776) y Cirriformia tentaculata (Montagu, 1808) dominaron en los niveles más profundos, observándose el incremento en el tamaño de los individuos con el aumento de la profundidad. Los análisis multivariantes reflejaron que el porcentaje de pelitas, la materia orgánica total y, especialmente, la relación lípidos malténicos/lípidos asfalténicos, fueron los principales factores condicionantes de la distribución vertical de las especies en el sedimento.Vertical distribution of the macrofauna in polluted sediments from the harbour of Ceuta Vertical distribution of the macrofauna and its relationship with physico-chemical parameters were studied in polluted sediments from the harbour of Ceuta. The samples were collected with cores (10 cm × 17 cm × 35 cm) by scuba divers. The following depths in the sediment column were included in the study: 0-2 cm, 2- 5 cm, 5-10 cm and more than 10 cm. The crustaceans Pariambus typicus Kröyer, 1844; Apseudes latreilli Milne-Edwards, 1820; Corophium runcicorne Della Valle, 1893; C. sextonae Crawford, 1937; the mollusc Parvicardium exiguum (Gmelin, 1791), and the polychaetes Pseudomalacoceros tridentata (Southern, 1914) and Exogone verrugera Cleparede, 1868 were found in the first 2 cm of the sediment, whereas the mollusc Loripes lacteus (L., 1758) and the polychaetes Platynereis dumerilii Audouin & Milne Edwards, 1833; Cirratulus cirratus (Muller, 1776) and Cirriformia tentaculata (Montagu, 1808) were dominant in deeper strata, and size increased with depth. A multivariate analysis showed that the percentage of silt and clays, the total organic matter, and especially, the maltenes/asphaltenes ratio, were the main factors affecting species’ vertical distribution