Rotating massive O stars with non-spherical 2D winds

We present solutions for the velocity field and mass-loss rates for 2D axisymmetric outflows, as well as for the case of mass accretion through the use of the Lambert W-function. For the case of a rotating radiation-driven wind the velocity field is obtained analytically using a parameterised description of the line acceleration that only depends on radius r at any given latitude $\theta$. The line acceleration g(r) is obtained from Monte-Carlo multi-line radiative transfer calculations. The critical/sonic point of our equation of motion varies with latitude $\theta$. Furthermore, an approximate analytical solution for the supersonic flow of a rotating wind is derived, which is found to closely resemble the exact solution. For the simultaneous solution of the mass-loss rate and velocity field, we use the iterative method of our 1D method extended to the non-spherical 2D case. We apply the new theoretical expressions with our iterative method to the stellar wind from a differentially rotating 40 $M_{sun}$ O5-V main sequence star as well as to a 60 $M_{sun}$ O-giant star, and we compare our results to previous studies that are extensions of the Castor et al. (1975, ApJ, 195, 157) CAK formalism. Next, we account for the effects of oblateness and gravity darkening. Our numerical results predict an equatorial decrease of the mass-loss rate, which would imply that (surface-averaged) total mass-loss rates are lower than for the spherical 1D case, in contradiction to the Maeder & Meynet (2000, A&A, 361, 159) formalism that is oftentimes employed in stellar evolution calculations for rotating massive stars. To clarify the situation in nature we discuss observational tests to constrain the shapes of large-scale 2D stellar winds.Comment: 20 pages, 4 figures, 7 tables, accepted for publication in A&A, (one corrected sentence in sect. 4.1.), a generalization of arXiv paper: arXiv:0810.190

The Role of Surprise in Hindsight Bias – A Metacognitive Model of Reduced and Reversed Hindsight Bias

Hindsight bias is the well researched phenomenon that people falsely believe that they would have correctly predicted the outcome of an event once it is known. In recent years, several authors have doubted the ubiquity of the effect and have reported a reversal under certain conditions. This article presents an integrative model on the role of surprise as one factor explaining the malleability of the hindsight bias. Three ways in which surprise influences the reconstruction of pre-outcome predictions are assumed: (1) Surprise is used as direct metacognitive heuristic to estimate the distance between outcome and prediction. (2) Surprise triggers a deliberate sense-making process, and (3) also biases this process by enhancing the retrieval of surprise-congruent information and expectancy-based hypothesis testing.

Configuration Management – A Core Competence for Successful through-life Systems Engineering and Engineering Services

AbstractThrough-life engineering services depend on capabilities to track and trace long-living systems and their components throughout the lifecycle. System configurations need to be known to (re)engineer, build, operate, maintain, and dispose systems in a sustainable way. Configuration Management (CM) is an approach to control system configurations with dedicated engineering processes, methods and tools – today foremost supported by information systems. This paper motivates CM implementation for through-life engineering services and systems engineering and related topics such as PSS (Product-Service Systems) and MRO (Maintenance, Repair, and Overhaul). CM fundamentals and related engineering activities are introduced briefly. Different CM views and daily challenges of CM for long-living complex systems are investigated. Software support for CM is discussed on the basis of PLM (Product Lifecycle Management) solutions. The paper highlights points that need attention for CM implementation (CM data and process management) by means of PLM. The paper summarizes requirements for CM based on PDM/PLM solutions, which are relevant for PLM solution vendors and for engineering companies and manufacturers moving towards PSS and MRO. The paper is written form an engineering perspective

Applying the Concept of Europeanization to the Study of Foreign Policy: Dimensions and Mechanisms

Recent years have witnessed a growing interest in applying the Europeanization concept to the study of foreign policy. Discussing how foreign policy Europeanization relates to Europeanization research in other areas of EU governance as well as to traditional approaches from the International Relations discipline, we examine the added value of studying foreign policy through the lens of Europeanization. As there is by now a considerable diversity of explanations for EU-induced changes of the national foreign policies of EU Member States, we propose important conceptual refinements, providing a clear distinction between the dimensions of Europeanization, their respective outcomes and particularly the mechanisms that drive Europeanization in these different dimensions. Overall, this working paper illustrates that Europeanization research addresses important shortcomings of International Relations approaches dominant in the field of European foreign policy analysis. By focusing on the interplay of “top-down” and “bottom-up” dynamics between the EU and national levels, which have been previously considered as isolated phenomena, the Europeanization concept contributes to a better understanding of the complex nature of European foreign policy-making.Europeanization; CFSP/ESDP; CFSP/ESDP; CFSP/ESDP; international relations; expert committees; socialization; national interest; political science

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