3,939 research outputs found

    The Hamburg/ESO R-process Enhanced Star survey (HERES) IV. Detailed abundance analysis and age dating of the strongly r-process enhanced stars CS 29491-069 and HE 1219-0312

    Full text link
    We report on a detailed abundance analysis of two strongly r-process enhanced, very metal-poor stars newly discovered in the HERES project, CS 29491-069 ([Fe/H]=-2.51, [r/Fe]=+1.1) and HE 1219-0312 ([Fe/H]=-2.96, [r/Fe]=+1.5). The analysis is based on high-quality VLT/UVES spectra and MARCS model atmospheres. We detect lines of 15 heavy elements in the spectrum of CS 29491-069, and 18 in HE 1219-0312; in both cases including the Th II 4019 {\AA} line. The heavy-element abundance patterns of these two stars are mostly well-matched to scaled solar residual abundances not formed by the s-process. We also compare the observed pattern with recent high-entropy wind (HEW) calculations, which assume core-collapse supernovae of massive stars as the astrophysical environment for the r-process, and find good agreement for most lanthanides. The abundance ratios of the lighter elements strontium, yttrium, and zirconium, which are presumably not formed by the main r-process, are reproduced well by the model. Radioactive dating for CS 29491-069 with the observed thorium and rare-earth element abundance pairs results in an average age of 9.5 Gyr, when based on solar r-process residuals, and 17.6 Gyr, when using HEW model predictions. Chronometry seems to fail in the case of HE 1219-0312, resulting in a negative age due to its high thorium abundance. HE 1219-0312 could therefore exhibit an overabundance of the heaviest elements, which is sometimes called an "actinide boost"

    The challenge of policy coordination for sustainable sociotechnical transitions: the case of the zero-carbon homes agenda in England

    Get PDF
    Emerging in recent research on sociotechnical transitions towards a low-carbon economy is the question of the extent to which such transitions require centralised, intentional coordination by government. Drawing from Hayek's conceptualisation of coordination, I evaluate the effectiveness of policy for low-carbon and zero-carbon homes in England. A detailed analysis is presented of how policy makers address complex choices and trade-offs as well as significant uncertainty. Particular attention is given to those policy decisions which are widely agreed by stakeholders to cause distortive effects. The focus here on the impacts of policy definition and delivery in terms of multiple evaluative criteria can complement and enrich the more process-orientated cross-sector and multilevel analyses that predominate in existing research on policy coordination. Furthermore, the coordination problems identified yield further insights into the actual and potential effectiveness of policy processes in shaping complex sociotechnical transitions

    From Anti-equilibrium to The Socialist System and Beyond

    Get PDF
    This essay attempts to understand János Kornai’s works from a political economy perspective. It argues that Kornai has significantly contributed to the formation of a new paradigm of political economy. The main endeavor of Kornai has been the combination of analytical concepts of economics with the empirical description of real economies. After a certain period of theoretical experimentation János Kornai formulated his research program that can be called the shortage economy explanation of the socialist system. The Economics of Shortage and The Socialist System have created a new theoretical paradigm in a framework in which it has become possible to establish a connection between the analytical and empirical, universal and historical aspects of the theory studying the socialist system as a real economic entity. János Kornai has built his analysis of the socialist system on the primary role of politics in the creation of economic institutions. In his present work on capitalism he has extended this thesis to the capitalist system. This seems to be an important contribution of his to a new political economy paradigm that is just in the process of formation

    Globalisation, neo-liberalism and vocational learning: the case of English further education colleges

    Get PDF
    Further education (FE) has traditionally been a rather unspectacular activity. Lacking the visibility of schools or the prestige of universities, for the vast majority of its existence FE has had a relatively low profile on the margins of English education. Over recent years this situation has altered significantly and further education has undergone profound change. This paper argues that a combination of related factors – neo-liberalism, globalisation, and dominant discourses of the knowledge economy – has acted in synergy to transform FE into a highly performative and marketised sector. Against this backdrop, further education has been assigned a particular role based upon certain narrow and instrumental understandings of skill, employment and economic competitiveness. The paper argues that, although it has always been predominantly working class in nature, FE is now, more than ever, positioned firmly at the lower end of the institutional hierarchy in the highly class-stratified terrain of English education

    Measurement of UNILAC and SIS18 proton performance

    Get PDF
    On July 16th 2016 the UNILAC and SIS18 proton performance has been measured. Due to scheduled maintenance works of the UNILAC's rf-system, the post-stripper energy was restricted to 5.9~MeV and accordingly the beam quality suffered considerably from the interruption of the periodic focusing system. This limitation will not be any longer in future beam times. Six single-gap resonators were used for acceleration to 10.7~MeV. After an optimization of the multi-turn injection 1.2â‹…1011\pmb{1.2\cdot10^{11}} protons were extracted form the SIS18

    Commensurability and beyond: from Mises and Neurath to the future of the socialist calculation debate

    Get PDF
    Mises' 'calculation argument' against socialism argues that monetary calculation is indispensable as a commensurable unit for evaluating factors of production. This is not due to his conception of rationality being purely 'algorithmic,' for it accommodates non-monetary, incommensurable values. Commensurability is needed, rather, as an aid in the face of economic complexity. The socialist Neurath's response to Mises is unsatisfactory in rejecting the need to explore possible non-market techniques for achieving a certain degree of commensurability. Yet Neurath's contribution is valuable in emphasizing the need for a balanced, comparative approach to the question of market versus non-market that puts the commensurability question in context. These central issues raised by adversaries in the early socialist calculation debate have continued relevance for the contemporary discussion

    Framing the neoliberal canon: resisting the market myth via literary enquiry

    Get PDF
    here is widespread recognition that neoliberal rhetoric about ‘free markets’ stands in considerable tension with ‘really existing’ neoliberalizing processes. However, the oft-utilized analytical distinction between ‘pure’ economic and political theory and ‘messy’ empirical developments takes for granted that neoliberalism, at its core, valorizes free markets. In contrast, the paper explores whether neoliberal intellectuals ever made such an argument. Using Friedrich Hayek and Milton Friedman as exemplars, our reading of canonical neoliberal texts focuses on author framing gestures, particular understandings of the term ‘science’, techniques of characterization, and constructions of epistemological legitimacy. This enables us to avoid the trap of assuming that these texts are about free markets and instead enquires into their constitution as literary artefacts. As such, we argue that the remaking of states and households rather than the promotion of free markets is at the core of neoliberalism. Our analysis has significant implications. For example, it means that authoritarian neoliberalism is not a departure from but actually more in line with the ‘pure’ neoliberal canon than in the past. Therefore, neoliberalism ought to be critiqued not for its rhetorical promotion of free markets but instead for seeking to reorganize societies in coercive, non-democratic and unequal ways. This also enables us to acknowledge that households are central to resistance to neoliberalism as well as to the neoliberal worldview itself

    Results of the experiments on emittance transfer EMTEX

    Get PDF
    • …
    corecore