1,288 research outputs found

    The troubadour Marcabru and his public

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    Vanadium(V)-containing oxides show superior intercalation properties for alkaline ions, although the performance of the material strongly depends on its surface morphology. In this work, intercalation activity of LiV3_{3}O8_{8}, prepared by a conventional solid state synthesis, is demonstrated for the first time in non-aqueous Li,Na-ion hybrid batteries with Na as negative electrode, and different Na/Li ratios in the electrolyte. In the pure Na-ion cell, one Na per formula unit of LiV3_{3}O8_{8} can be reversibly inserted at room temperature via a two-step process, while further intercalation leads to gradual amorphisation of the material, with a specific capacity of 190 mAhg−1^{−1} after 10 cycles in the potential window of 0.8–3.4 V. Hybrid Li,Na-ion batteries feature simultaneous intercalation of Li+^+ and Na+^+ cations into LiV3_{3}O8_{8}, resulting in the formation of a second phase. Depending on the electrolyte composition, this second phase bears structural similarities either to Li0.7_{0.7}Na0.7_{0.7}V3_{3}O8_{8} in Na-rich electrolytes, or to LiV3_{3}O8_{8} in Li-rich electrolytes. The chemical diffusion coefficients of Na+ and Li+ in crystalline LiV3_{3}O8_{8} are very close, hence explaining the co-intercalation of these cations. As DFT calculations show, once formed, the Li0.7_{0.7}Na0.7_{0.7}V3_{3}O8_{8}-type structure favors intercalation of Na+^+, whereas the LiV3_{3}O8_{8}-type prefers to accommodate Li+^+ cations

    Calculation of the Aharonov-Bohm wave function

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    A calculation of the Aharonov-Bohm wave function is presented. The result is a series of confluent hypergeometric functions which is finite at the forward direction.Comment: 12 pages in LaTeX, and 3 PostScript figure

    The Single-Particle density of States, Bound States, Phase-Shift Flip, and a Resonance in the Presence of an Aharonov-Bohm Potential

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    Both the nonrelativistic scattering and the spectrum in the presence of the Aharonov-Bohm potential are analyzed. The single-particle density of states (DOS) for different self-adjoint extensions is calculated. The DOS provides a link between different physical quantities and is a natural starting point for their calculation. The consequences of an asymmetry of the S matrix for the generic self-adjoint extension are examined. I. Introduction II. Impenetrable flux tube and the density of states III. Penetrable flux tube and self-adjoint extensions IV. The S matrix and scattering cross sections V. The Krein-Friedel formula and the resonance VI. Regularization VII. The R --> 0 limit and the interpretation of self-adjoint extensions VIII. Energy calculations IX. The Hall effect in the dilute vortex limit X. Persistent current of free electrons in the plane pierced by a flux tube XI. The 2nd virial coefficient of nonrelativistic interacting anyons XII. Discussion of the results and open questionsComment: 68 pages, plain latex, 7 figures, 3 references and one figure added plus a few minor text correction

    Bayesian inference of biochemical kinetic parameters using the linear noise approximation

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    Background Fluorescent and luminescent gene reporters allow us to dynamically quantify changes in molecular species concentration over time on the single cell level. The mathematical modeling of their interaction through multivariate dynamical models requires the deveopment of effective statistical methods to calibrate such models against available data. Given the prevalence of stochasticity and noise in biochemical systems inference for stochastic models is of special interest. In this paper we present a simple and computationally efficient algorithm for the estimation of biochemical kinetic parameters from gene reporter data. Results We use the linear noise approximation to model biochemical reactions through a stochastic dynamic model which essentially approximates a diffusion model by an ordinary differential equation model with an appropriately defined noise process. An explicit formula for the likelihood function can be derived allowing for computationally efficient parameter estimation. The proposed algorithm is embedded in a Bayesian framework and inference is performed using Markov chain Monte Carlo. Conclusion The major advantage of the method is that in contrast to the more established diffusion approximation based methods the computationally costly methods of data augmentation are not necessary. Our approach also allows for unobserved variables and measurement error. The application of the method to both simulated and experimental data shows that the proposed methodology provides a useful alternative to diffusion approximation based methods

    Legal Facts and Reasons for Action: Between Deflationary and Robust Conceptions of Law’s Reason-Giving Capacity

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    This chapter considers whether legal requirements can constitute reasons for action independently of the merits of the requirement at hand. While jurisprudential opinion on this question is far from uniform, sceptical views are becoming increasingly dominant. Such views typically contend that, while the law can be indicative of pre-existing reasons, or can trigger pre-existing reasons into operation, it cannot constitute new reasons. This chapter offers support to a somewhat less sceptical position, according to which the fact that a legal requirement has been issued can be a reason for action, yet one that is underpinned by bedrock values which law is apt to serve. Notions discussed here include a value-based conception of reasons as facts ; a distinction between complete and incomplete reasons ; and David Enoch’s idea of triggering reason-giving. Following a discussion of criticism against the view adopted here, the chapter concludes by considering some more ‘robust’ conceptions of law’s reason-giving capacity

    Depression:Diagnosis and suffering as process

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    The high rates of depression – as well as the widespread diagnosis of depression – are both controversial and contested in contemporary late-modern society. Issues of flawed definition have been voiced to account for the bourgeoning rates of depression and the diagnosis has been subject to criticism of medicalization and pharmaceuticalization. Others have stated that the actualization of depression is to be seen in light of societal and structural transformations. Be that as it may, depression is affecting more and more people and the diagnosis is prevalent. In this context, a more nuanced understanding of how people relate to, experience and ascribe meaning to their suffering as depression and being diagnosed as such is needed. This article draws on qualitative interviews from Denmark and Norway to explore lay accounts of depression in contemporary late-modern society. The findings reveal that lay accounts of suffering, including living with the diagnosis of depression is a dynamic process, meaning that people vacillate in and out of various perspectives of suffering and categorization to make it fit their specific life situation and prospects of the future. In this article we thus highlight the perspectives of thoroughly analyzing suffering and the diagnostic experience by applying the overall concept of process, which takes on different meanings in the course of the analysis. The final version of this research has been published in Nordic Psychology. © 2017 Taylor & Franci

    The bashful and the boastful : prestigious leaders and social change in Mesolithic Societies

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    The creation and maintenance of influential leaders and authorities is one of the key themes of archaeological and historical enquiry. However the social dynamics of authorities and leaders in the Mesolithic remains a largely unexplored area of study. The role and influence of authorities can be remarkably different in different situations yet they exist in all societies and in almost all social contexts from playgrounds to parliaments. Here we explore the literature on the dynamics of authority creation, maintenance and contestation in egalitarian societies, and discuss the implications for our interpretation and understanding of the formation of authorities and leaders and changing social relationships within the Mesolithic

    Unemployment, crime and social insurance

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    We study an individual's incentive to search for a job in the presence of random criminal opportunities. These opportunities extenuate moral hazard, as the individual sometimes commits crime rather than searching. Even when he searches, he applies less effort. We then revisit the design of optimal unemployment insurance in this environment. If the individual is more likely to remain unemployed and unpunished when he commits crime than when he searches for a job (as suggested by empirical studies), declining unemployment benefits reduce the payoff from crime relative to that from searching. Compared to the canonical models of optimal unemployment insurance, this provides a further incentive to reduce benefits over time

    Unlocking legal validity. Some remarks on the artificial ontology of law

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    Following Kelsen’s influential theory of law, the concept of validity has been used in the literature to refer to different properties of law (such as existence, membership, bindingness, and more) and so it is inherently ambiguous. More importantly, Kelsen’s equivalence between the existence and the validity of law prevents us from accounting satisfactorily for relevant aspects of our current legal practices, such as the phenomenon of ‘unlawful law’. This chapter addresses this ambiguity to argue that the most important function of the concept of validity is constituting the complex ontological paradigm of modern law as an institutional-normative practice. In this sense validity is an artificial ontological status that supervenes on that of existence of legal norms, thus allowing law to regulate its own creation and creating the logical space for the occurrence of ‘unlawful law’. This function, I argue in the last part, is crucial to understanding the relationship between the ontological and epistemic dimensions of the objectivity of law. For given the necessary practice-independence of legal norms, it is the epistemic accessibility of their creation that enables the law to fulfill its general action-guiding (and thus coordinating) function
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