The fluid mechanics of bubbly drinks

Bubbly drinks are surprisingly attractive. There is something about the nature of the these beverages that make them preferable among other choices. In this article we explore the physics involved in this particular kind of two-phase, mass-transfer-driven flows.Comment: Extended version of Zenit R and Rodr\'iguez-Rodr\'iguez J. The fluid mechanics of bubbly drinks. Physics Today, Vol. 71(11) pp. 44-50, November 201

Presentación del libro de Mario Orellana Rodríguez, "Organización y administración de la justicia española en los primeros años de la conquista de Chile"

- Dougnac Rodríguez, Antonio. Presentación del libro de Mario Orellana Rodríguez, "Organización y administración de la justicia española en los primeros años de la conquista de Chile".- Dougnac Rodríguez, Antonio. Encuentro con José María Mariluz Urquijo en el Instituto de Chile (Semblanza a don Ricardo Levene).- Barahona Gallardo, Claudio. IV Jornadas Chileno-Peruanas de Historia del Derecho.- Barahona Gallardo, Claudio. Encuentros en la Academia. Segunda Conferencia 2014: Antonio Dougnac Rodríguez- Barahona Gallardo, Claudio. Conferencia "Lo que hay de más y menos en la historia de Chile. En busca de los hilos perdidos"

Revisión taxonómica del complejo de Centaurea cyanus L. (Centaurea sect. Cyanus, Asteraceae) en la Península Ibérica

Revisión taxonómica del complejo de Centaurea cyanus L. (Centaurea sect. Cyanus, Asteraceae) en la Península Ibérica. Se ha efectuado la revisión taxonómica de Centaurea sect. Cyanus en la Península Ibérica. Se reconocen seis táxones y se hacen dos nuevas combinaciones: C. triumfettii var. semidecurrens (Jord.) Muñoz Rodr. & Devesa y C. graminifolia (Lam.) Muñoz Rodr. & Devesa. Se aporta una clave para la identificación de los táxones, así como su descripción morfológica e información sobre la distribución geográfica, apetencias ecológicas, fenología y número cromosómico

An attempt to identify the extended synchrotron structure associated with the micro-quasar GRS 1915+105

The energy ejected from the galaxy micro-quasar GRS1915+105 in the form of jets is expected to lead to formation of an extended double lobe/hot-spot structure with the energy content comparable to an average supernova remnant. We used the Effelsberg 100m telescope at 10.45 GHz in attempt to identify such structures. For this distant galactic plane source any definite identification was not possible due to high confusion by numerous background sources, however, a few suspect structures were pointed out.Comment: LaTeX uses a new 2001 A&A macro, 4 pages, 2 figures, A&A accepte

How Important is Syntactic Parsing Accuracy? An Empirical Evaluation on Rule-Based Sentiment Analysis

Syntactic parsing, the process of obtaining the internal structure of sentences in natural languages, is a crucial task for artificial intelligence applications that need to extract meaning from natural language text or speech. Sentiment analysis is one example of application for which parsing has recently proven useful. In recent years, there have been significant advances in the accuracy of parsing algorithms. In this article, we perform an empirical, task-oriented evaluation to determine how parsing accuracy influences the performance of a state-of-the-art rule-based sentiment analysis system that determines the polarity of sentences from their parse trees. In particular, we evaluate the system using four well-known dependency parsers, including both current models with state-of-the-art accuracy and more innacurate models which, however, require less computational resources. The experiments show that all of the parsers produce similarly good results in the sentiment analysis task, without their accuracy having any relevant influence on the results. Since parsing is currently a task with a relatively high computational cost that varies strongly between algorithms, this suggests that sentiment analysis researchers and users should prioritize speed over accuracy when choosing a parser; and parsing researchers should investigate models that improve speed further, even at some cost to accuracy.Comment: 19 pages. Accepted for publication in Artificial Intelligence Review. This update only adds the DOI link to comply with journal's term

The magnetic SW Sextantis star RX J1643.7+3402

We present time-resolved spectroscopy and circular spectropolarimetry of the SW Sex star RX J1643.7+3402. We find significant polarisation levels exhibiting a variability at a period of 19.38 +- 0.39 min. In addition, emission-line flaring is found predominantly at twice the polarimetric period. These two findings are strong evidences in favour of the presence of a magnetic white dwarf in the system. We interpret the measured periodicities in the context of our magnetic accretion model for SW Sex stars. In contrast with LS Pegasi -the first SW Sex star discovered to have modulated circular polarisation- the polarisation in RX J1643.7+3402 is suggested to vary at 2(omega - Omega), while the emission lines flare at (omega - Omega). However, a 2omega/omega interpretation cannot be ruled out. Together with LS Peg and V795 Her, RX J1643.7+3402 is the third SW Sex star known to exhibit modulated circular polarisation.Comment: 7 pages, 4 figures, accepted for publication in MNRA