What is the Shell Around R Coronae Borealis?

The hydrogen-deficient, carbon-rich R Coronae Borealis (RCB) stars are known for being prolific producers of dust which causes their large iconic declines in brightness. Several RCB stars, including R CrB, itself, have large extended dust shells seen in the far-infrared. The origin of these shells is uncertain but they may give us clues to the evolution of the RCB stars. The shells could form in three possible ways. 1) they are fossil Planetary Nebula (PN) shells, which would exist if RCB stars are the result of a final, helium-shell flash, 2) they are material left over from a white-dwarf merger event which formed the RCB stars, or 3) they are material lost from the star during the RCB phase. Arecibo 21-cm observations establish an upper limit on the column density of H I in the R CrB shell implying a maximum shell mass of $\lesssim$0.3 M$_{\odot}$. A low-mass fossil PN shell is still a possible source of the shell although it may not contain enough dust. The mass of gas lost during a white-dwarf merger event will not condense enough dust to produce the observed shell, assuming a reasonable gas-to-dust ratio. The third scenario where the shell around R CrB has been produced during the star's RCB phase seems most likely to produce the observed mass of dust and the observed size of the shell. But this means that R CrB has been in its RCB phase for $\sim$10$^{4}$ yr.Comment: 5 pages, 2 figures, 2 tables, Accepted for publication in A

What is the probability of intersecting the set of Brownian double points?

We give potential theoretic estimates for the probability that a set $A$ contains a double point of planar Brownian motion run for unit time. Unlike the probability for $A$ to intersect the range of a Markov process, this cannot be estimated by a capacity of the set $A$. Instead, we introduce the notion of a capacity with respect to two gauge functions simultaneously. We also give a polar decomposition of $A$ into a set that never intersects the set of Brownian double points and a set for which intersection with the set of Brownian double points is the same as intersection with the Brownian path.Comment: Published in at http://dx.doi.org/10.1214/009117907000000169 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

What is the Philology Author?

Este artículo pretende definir la filología de autor y, para ello, atenderá a su génesis, donde cobran especial importancia las figuras de Contini e Isella, a sus premisas básicas, que la diferencian de la crítica genética francesa y al radical cambio al que está sometida hoy nuestra disciplina. La filología de autor, que implica además una interpretación personal por parte del crítico, refleja dicha interpretación no solo en la lección escogida del texto, sino en la propia construcción del aparato crítico, que podrá ser genético o evolutivo. Todas estas cuestiones básicas se explican a partir de los Idilli de Leopardi o Fermo e Lucia de Manzoni, entre otros ejemplos.The aim of the article is to define author’s philology, and in order to do so, it will look at its beginnings, where we find the relevance of the figures of Contini an Isella, at its basic premises, which make it differ from French genetic criticism, and at the radical transformation to which our discipline is exposed today. Author’s philology, which also entails a personal interpretation on the critic’s part, projects this interpretation not only in the lesson chosen from the text, but also in the construction itself of the critical apparatus, which may be genetic or evolutive. All these basic issues are dealt with taking the Idilli, by Leopardi, or Fermo e Lucia, by Manzoni, as basis, among others

What is the optimal shape of a fin for one dimensional heat conduction?

This article is concerned with the shape of small devices used to control the heat flowing between a solid and a fluid phase, usually called \textsl{fin}. The temperature along a fin in stationary regime is modeled by a one-dimensional Sturm-Liouville equation whose coefficients strongly depend on its geometrical features. We are interested in the following issue: is there any optimal shape maximizing the heat flux at the inlet of the fin? Two relevant constraints are examined, by imposing either its volume or its surface, and analytical nonexistence results are proved for both problems. Furthermore, using specific perturbations, we explicitly compute the optimal values and construct maximizing sequences. We show in particular that the optimal heat flux at the inlet is infinite in the first case and finite in the second one. Finally, we provide several extensions of these results for more general models of heat conduction, as well as several numerical illustrations

What Is Wrong with the No-Report Paradigm and How to Fix It

Is consciousness based in prefrontal circuits involved in cognitive processes like thought, reasoning, and memory or, alternatively, is it based in sensory areas in the back of the neocortex? The no-report paradigm has been crucial to this debate because it aims to separate the neural basis of the cognitive processes underlying post-perceptual decision and report from the neural basis of conscious perception itself. However, the no-report paradigm is problematic because, even in the absence of report, subjects might engage in post-perceptual cognitive processing. Therefore, to isolate the neural basis of consciousness, a no-cognition paradigm is needed. Here, I describe a no-cognition approach to binocular rivalry and outline how this approach can help resolve debates about the neural basis of consciousness

Vehicle-to-Grid - What is the Benefit for a Sustainable Mobility?

The demand for vehicles in industrialised countries is dropping and the growth rate in developing countries is slowing down rapidly. Driver of this evolution is evidently the current crisis but also the expectation that in the long run oil will not be sufficient and finally. Paper discus about that situation.vehicles, mobility

Energy, gender and development: what are the linkages ? where is the evidence ?

This report reviews the literature on the links between energy access, welfare, and gender in order to provide evidence on where gender considerations in the energy sector matter and how they might be addressed. Prepared as a background document for the 2012 World Development Report on Gender Equality and Development, and part of the Social Development Department's ongoing work on gender and infrastructure, the report describes and evaluates the evidence on the links between gender and energy focusing on: increased access to woodfuel through planting of trees and forest management; improved cooking technologies; and access to electricity and motive energy. The report's main finding is that energy interventions can have significant gender benefits, which can be realized via careful design and targeting of interventions based on a context-specific understanding of energy scarcity and household decision-making, in particular how women's preferences, opportunity cost of time, and welfare are reflected in household energy decisions. The report focuses on the academic peer-reviewed literature and, although it applies fairly inclusive screening criteria when selecting the evidence to consider, finds that the evidence on many of the energy-gender linkages is often limited. There is thus a clear need for studies to evaluate interventions and identify key design elements for gender-sensitive project design.