Multiscale velocity correlations in turbulence and Burgers turbulence: Fusion rules, Markov processes in scale, and multifractal predictions

We compare different approaches towards an effective description of multi-scale velocity field correlations in turbulence. Predictions made by the operator product expansion, the so-called fusion rules, are placed in juxtaposition to an approach that interprets the turbulent energy cascade in terms of a Markov process of velocity increments in scale. We explicitly show that the fusion rules are a direct consequence of the Markov property provided that the structure functions exhibit scaling in the inertial range. Furthermore, the limit case of joint velocity gradient and velocity increment statistics is discussed and put into the context of the notion of dissipative anomaly. We generalize a prediction made by the multifractal (MF) approach derived in [Phys. Rev. Lett. 80, 3244 (1998)] to correlations among inertial range velocity increment and velocity gradients of any order. We show that for the case of squared velocity gradients such a relation can be derived from "first principles" in the case of Burgers equation. Our results are benchmarked by intensive direct numerical simulations of Burgers turbulence.Comment: 18 pages, 6 figure

Soziale Kosten von Stromerzeugungssystemen

Der beschlossene Ausstieg aus der Kernenergie und die ehrgeizigen Klima-schutzziele erfordern einen Umbau des Stromerzeugungssystems in Deutschland. Rainer Friedrich, Universität Stuttgart, geht der Frage nach, welche Stromerzeugungstechniken in einem zukünftigen Stromerzeugungssystem eingesetzt werden sollten, wobei nicht nur die Stromerzeugungskosten, sondern auch externe Effekte mit zu berücksichtigen sind. Seiner Ansicht nach sind Laufwasser, gefolgt von Braunkohle, Wind, evtl. Wellenenergie und Steinkohle, die Optionen mit den niedrigsten sozialen Kosten. Aber da das Potenzial von Wind und Laufwasser begrenzt sei, Wind und Wellenenergie Reserve- oder Speicherkapazität benötigen und On-shore-Windkraft nicht überall akzeptiert sei, erweist sich vor allem Braunkohle als günstig.Energieversorgung, Nachhaltige Entwicklung, Reform, Umweltverträgliche Energiepolitik, Deutschland

Methodology for Estimating the Lifelong Exposure to PM2.5 and NO2 - The Application to European Population Subgroups

Health impacts of air pollutants, especially fine particles (PM2.5) and NO2, have been documented worldwide by epidemiological studies. Most of the existing studies utilised the concentration measured at the ambient stations to represent the pollutant inhaled by individuals. However, these measurement data are in fact not able to reflect the real concentration a person is exposed to since people spend most of their time indoors and are also affected by indoor sources. The authors developed a probabilistic methodology framework to simulate the lifelong exposure to PM2.5 and NO2 simultaneously for population subgroups that are characterised by a number of indicators such as age, gender and socio-economic status. The methodology framework incorporates the methods for simulating the long-term outdoor air quality, the pollutant concentration in different micro-environments, the time-activity pattern of population subgroups and the retrospective life course trajectories. This approach was applied to the population in the EU27 countries plus Norway and Switzerland and validated with the measurement data from European multi-centre study, EXPOLIS. Results show that the annual average exposure to PM2.5 and NO2 at European level kept increasing from the 1950s to a peak between the 1980s and the 1990s and showed a decrease until 2015 due to the implementation of a series of directives. It is also revealed that the exposure to both pollutants was affected by geographical location, gender and income level. The average annual exposure over the lifetime of an 80-year-old European to PM2.5 and NO2 amounted to 23.86 (95% CI: 2.95-81.86) and 13.49 (95% CI: 1.36-43.84) µg/m3. The application of this methodology provides valuable insights and novel tools for exposure modelling and environmental studies

RoCKIn: Impact on Future Markets for Robotics

The goal of the project “Robot Competitions Kick Innovation in Cognitive Systems and Robotics” (RoCKIn), funded by the European Commission under its 7th Framework Program, has been to speed up the progress toward smarter robots through scientific competitions. Two challenges have been selected for the competitions due to their high relevance and impact on Europe’s societal and industrial needs: domestic service robots (“RoCKIn@Home”) and innovative robot applications in industry (“RoCKIn@Work”). The history and reasoning behind the chosen task and functionality benchmarks in RoCKIn are explained by providing an insight from the International Federation of Robotics and an analysis on RoCKIn’s impact on the industrial robot market domain is carried out. To paint a broad picture, RoCKIn is compared to other robot competitions and similarities, differences and challenges those competitions share are pointed out. Some industrial robot market requirements and the way RoCKIn addressed them are explained. Strength and weaknesses of the project in regard to their market impact are emphasized and it is shown how these were continued and addressed by RoCKIn’s successor European Robotics League (ERL)