Radial displacement of a fluid annulus in a rotating Hele-Shaw cell

The radial displacement of a fluid annulus in a rotating circular HeleShaw cell has been investigated experimentally. It has been found that the flow depends sensitively on the wetting conditions at the outer interface. Displacements in a prewet cell are well described by Darcy"s law in a wide range of experimental parameters, with little influence of capillary effects. In a dry cell, however, a more careful analysis of the interfacemotion is required; the interplay between a gradual loss of fluid at the inner interface, and the dependence of capillary forces at the outer interface on interfacial velocity and dynamic contact angle, result in a constant velocity for the interfaces. The experimental results in this case correlate in the form of an empirical scaling relation between the capillary number Ca and a dimensionless group, related to the ratio of centrifugal to capillary forces, which spans about three orders of magnitude in both quantities. Finally, the relative thickness of the coating film left by the inner interface is obtained as a function of Ca.

Estudi de pràctiques d’educació infantil: la participació com a recurs d’inclusió

El nostre estudi és una investigació educativa amb metodologia qualitativa que, a través de l’anàlisi de contingut, vol determinar si existeixen indicadors que tenen un pes específic més rellevant per assolir un alt grau de participació a l’aula, entenent que aquesta és un element d’atenció a la diversitat en la perspectiva de l’educació inclusiva. La mostra analitzada consta de quaranta-nou experiències educatives extretes de la Revista Infàn- ci-a de l’Associació de Mestres Rosa Sensat, en l’apartat Escola 3-6, des del novembre-desembre del 2009 i fins al novembre-desembre del 2013. L’instrument d’anàlisi ha estat una fitxa d’observació formada per una sèrie d’indicadors extrets del marc teòric. Els resultats mostren que hi ha uns indicadors que tenen una major rellevància quan es fan activitats d’ensenyament-aprenentatge amb un alt grau de participació. Per tant, els docents hauran de tenir en compte aquests indicadors per portar a terme pràctiques educatives inclusives amb alts índex de participació.

La adaptación a la jubilación y sus fases: afectación de los niveles de satisfacción y duración del proceso adaptativo

This research attempted to describe, according to the model of Atchley (1975), the experience of the adaptive phases, the changes of life satisfaction levels and the duration of the process and its phases. A total of 30 retired people were interviewed in depth, representated their Life Chart Methodology-retrospective (LCM-r) on the life satisfaction levels and responded to the Life Satisfaction Index. The results show that even though the retirees did not all experience exactly the same adjustment processes, most of the stages were found. It is also noteworthy that during the adustment process large fluctuations were observed in the level of satisfaction experienced by the participants, but once they had adjusted to retirement their degree of satisfaction returned to levels similar to those reported before retirement. Substantial differences were also found with regards to the duration of the adjustment process, which fluctuated from six months to more than a year

Hacia el liaison librarian: transformación de servicios bibliotecarios para dar apoyo a la docencia en la Universitat Oberta de Catalunya (UOC)

Es descriu la transformació esdevinguda en els últims dos anys en un dels dos grups operatius de la Biblioteca Virtual de la Universitat Oberta de Catalunya (UOC), l'equip de Serveis de Biblioteca per a l'Aprenentatge (SBA), que té com a objectiu principal el suport al procés d'aprenentatge i la docència. Es descriu en detall l'elaboració d'una carta de serveis específica per als docents, el propòsit del qual és acompanyar-los en la recerca i selecció de recursos d'aprenentatge per a les assignatures que s'imparteixen a la UOC.

Effect of long-range Coulomb interaction on shot-noise suppression in ballistic transport

We present a microscopic analysis of shot-noise suppression due to long-range Coulomb interaction in semiconductor devices under ballistic transport conditions. An ensemble Monte Carlo simulator self-consistently coupled with a Poisson solver is used for the calculations. A wide range of injection-rate densities leading to different degrees of suppression is investigated. A sharp tendency of noise suppression at increasing injection densities is found to scale with a dimensionless Debye length related to the importance of space-charge effects in the structure.

The Role of the Delay Time in the Modeling of Biological Range Expansions

The time interval between successive migrations of biological species causes a delay time in the reaction-diffusion equations describing their space-time dynamics. This lowers the predicted speed of the waves of advance, as compared to classical models. It has been shown that this delay-time effect improves the modeling of human range expansions. Here, we demonstrate that it can also be important for other species. We present two new examples where the predictions of the time-delayed and the classical (Fisher) approaches are compared to experimental data. No free or adjustable parameters are used. We show that the importance of the delay effect depends on the dimensionless product of the initial growth rate and the delay time. We argue that the delay effect should be taken into account in the modeling of range expansions for biological species