Percolation study for the capillary ascent of a liquid through a granular soil

Capillary rise plays a crucial role in the construction of road embankments in flood zones, where hydrophobic compounds are added to the soil to suppress the rising of water and avoid possible damage of the pavement. Water rises through liquid bridges, menisci and trimers, whose width and connectivity depends on the maximal half-length {\lambda} of the capillary bridges among grains. Low {\lambda} generate a disconnect structure, with small clusters everywhere. On the contrary, for high {\lambda}, create a percolating cluster of trimers and enclosed volumes that form a natural path for capillary rise. Hereby, we study the percolation transition of this geometric structure as a function of {\lambda} on a granular media of monodisperse spheres in a random close packing. We determine both the percolating threshold {\lambda}_{c} = (0.049 \pm 0.004)R (with R the radius of the granular spheres), and the critical exponent of the correlation length {\nu} = (0.830 \pm 0.051), suggesting that the percolation transition falls into the universality class of ordinary percolation

The pupal morphology of the Carabus (s. l.) (Coleoptera, Carabidae) in the southwestern Iberian peninsula

The pupae of Carabus (s. l.) of the south-west Iberian peninsula are described. The study was carried out with pupae of Macrothorax rugosus (Fabricius, 1792), Hadrocarabus dufouri (Dejean, 1831), H. lusitanicus (Fabricius, 1801) and Rhabdotocarabus melancholicus (Fabricius, 1798) reared in the laboratory from adults caught in the field. By determining and testing various morphological structures, all three genera were identified. These results indicate that the presence or absence of setae on the pronotum, the distribution of hairs on the abdominal tergi and the development of tergal expansions from urotergi are the most significant features for identification

Degree of Quantumness in Quantum Synchronization

We introduce the concept of degree of quantumness in quantum synchronization, a measure of the quantum nature of synchronization in quantum systems. Following techniques from quantum information, we propose the number of non-commuting observables that synchronize as a measure of quantumness. This figure of merit is compatible with already existing synchronization measurements, and it captures different physical properties. We illustrate it in a quantum system consisting of two weakly interacting cavity-qubit systems, which are coupled via the exchange of bosonic excitations between the cavities. Moreover, we study the synchronization of the expectation values of the Pauli operators and we propose a feasible superconducting circuit setup. Finally, we discuss the degree of quantumness in the synchronization between two quantum van der Pol oscillators

Weak Z\mathcal Z-structures and one-relator groups

Motivated by the notion of boundary for hyperbolic and $CAT(0)$ groups, M. Bestvina in "Local Homology Properties of Boundaries of Groups" introduced the notion of a (weak) $\mathcal Z$-structure and (weak) $\mathcal Z$-boundary for a group $G$ of type $\mathcal F$ (i.e., having a finite $K(G,1)$ complex), with implications concerning the Novikov conjecture for $G$. Since then, some classes of groups have been shown to admit a weak $\mathcal Z$-structure (see "Weak $\mathcal Z$-structures for some classes of groups" by C.R. Guilbault for example), but the question whether or not every group of type $\mathcal F$ admits such a structure remains open. In this paper, we show that every torsion free one-relator group admits a weak $\mathcal Z$-structure, by showing that they are all properly aspherical at infinity; moreover, in the $1$-ended case the corresponding weak $\mathcal Z$-boundary has the shape of either a circle or a Hawaiian earring depending on whether the group is a virtually surface group or not. Finally, we extend this result to a wider class of groups still satisfying a Freiheitssatz property

Comprehensive transient-state study for CARMENES-NIR high thermal stability

CARMENES has been proposed as a next-generation instrument for the 3.5m Calar Alto Telescope. Its objective is finding habitable exoplanets around M dwarfs through radial velocity measurements (m/s level) in the near-infrared. Consequently, the NIR spectrograph is highly constraint regarding thermal/mechanical requirements. As a first approach, the thermal stability has been limited to \pm 0.01K (within year period) over a working temperature of 243K. This can be achieved by means of several temperature-controlled rooms. The options considered to minimise the complexity of the thermal design are here presented, as well as the transient-state thermal analyses realised to make the best choice

Situaciones problemáticas auténticas propuestas por estudiantes para maestro

En un contexto de formación inicial de maestros de matemáticas en Primaria, se analizó la autenticidad de situaciones problemáticas (SP) que estudiantes para maestro propusieron, en grupo, a partir de un contexto elegido por ellos mismos, y las mejoras posteriores de dichas propuestas cuando intentaron convertirlas en tareas auténticas. Después de analizar la autenticidad de las propuestas iniciales y finales a partir de las dimensiones consideradas, los resultados mostraron que se mejoraron muchas de las propuestas iniciales, pero no todas, lo que abre un camino a futura investigación con objetivos similares