1,799 research outputs found

    Personality and error monitoring: an update

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    Childhood in flux – Part II: Modern times until today

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    Ende des 19. Jahrhunderts wurde in New York die „Society for the Prevention of Cruelty to Children“ gegründet nach dem Bekanntwerden eines grausamen Falls von Vernachlässigung und Misshandlung eines Mädchens. Hiermit begann die Zeit, seitdem Kinder vermehrt Schutz erfahren. Doch erst in den 1950er Jahren wurde in den USA eine Anzeigepflicht für Ärzte eingeführt, die bei Verletzungen von Kindern Fälle von Misshandlung vermuteten. In Schweden wurde ein Körperstrafenverbot 1981, in Deutschland 2001 eingeführt. Der sexuelle Missbrauch von Kindern wurde über Jahrhunderte tabuisiert, wenngleich einzelne Versuche unternommen wurden, das Tabu zu durchbrechen – beispielsweise von S. Freud mit der Verführungstheorie. Erst mit der Frauenbewegung zu Beginn der 1970er Jahre wurde eine öffentliche Aufmerksamkeit hierfür geschaffen. Durch die Arbeiten des englischen Psychiaters J. Bowlby in den 1950er Jahren wurde das Bewusstsein befördert, dass Kinder von Primaten mehr brauchen als Luft, Wasser und Nahrung – nämlich die Bindung zu einer erwachsenen Bezugsperson. Inwieweit die grundlegenden Bedürfnisse von Kindern heute in den westlichen Kulturen erfüllt werden, wird kontrovers diskutiert.(DIPF/Orig.)At the end of the 19th century, the Society for the Prevention of Cruelty to Children was founded in New York, after a barbarous case of neglect and abuse of a girl became public. From then on, children received more and more protection. Only in the 1950s were doctors in the USA bound by law to report cases of putative physical abuse to officials. In Sweden, physical punishment of children has been forbidden since 1989, and in Germany since 2001. The existence of sexual abuse of children had been a taboo subject for centuries, even though individual attempts to break that taboo were made – e. g., by S. Freud in the theory of seduction (Verführungstheorie). Only with the birth of the women’s liberation movement in the early 1970s has public awareness arisen. Due to the work of J. Bowlby in the 1950s, it became clear that children of primates need more than air, water and food, namely a relationship between the child and an adult person (attachment). To what degree the basic needs of children are being fulfilled in Western societies today is still a controversial issue.(DIPF/Orig.

    Reacting Flow Prediction of the Low-Swirl Lifted Flame in an Aeronautical Combustor With Angular Air Supply

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    The development of lean-burn combustion systems is of paramount importance for reducing the pollutant emissions of future aero engine generations. By tilting the burners of an annular combustor in circumferential direction relative to the rotational axis of the engine, the potential of increased combustion stability is opened up due to an enhanced exhaust gas recirculation between adjacent flames. The innovative gas turbine combustor concept, called the Short Helical Combustor (SHC), allows the main reaction zone to be operated at low equivalence ratios. To exploit the higher stability of the fuel-lean combustion, a low-swirl lifted flame is implemented in the staggered SHC burner arrangement. The objective is to reach ultra-low NOx emissions by complete evaporation and extensive premixing of fuel and air upstream of the lean reaction zone. In the present work, a modeling approach is developed to investigate the characteristics of the lifted flame in an enclosed single-burner configuration, using the gaseous fuel methane. It is demonstrated that by using the Large Eddy Simulation method, the shape and lift-off height of the flame is adequately reproduced by means of the finite-rate chemistry approach. For the numerical prediction of the lean lifted flame in the SHC arrangement, the focus is on the interaction of adjacent burners. It is shown that the swirling jet flow is deflected towards the sidewall of the staggered combustor dome, which is attributed to the asymmetrical confinement. Since the stabilization mechanism of the low-swirl flame relies on outer recirculation zones, the upstream transport of hot combustion products back to the flame base is studied by the variation of the combustor confinement ratio. It turns out that increasing the combustor size amplifies the exhaust gas recirculation along the sidewall, and increases the temperature of recirculating burned gases. The present study emphasizes the capability of the proposed lean-burn combustor concept for future aero engine applications

    Reacting Flow Prediction of the Low-Swirl Lifted Flame in an Aeronautical Combustor With Angular Air Supply

    Get PDF
    The development of lean-burn combustion systems is of paramount importance for reducing the pollutant emissions of future aero engine generations. By tilting the burners of an annular combustor in circumferential direction relative to the rotational axis of the engine, the potential of increased combustion stability is opened up due to an enhanced exhaust gas recirculation between adjacent flames. The innovative gas turbine combustor concept, called the short helical combustor (SHC), allows the main reaction zone to be operated at low equivalence ratios. To exploit the higher stability of the fuel-lean combustion, a low-swirl lifted flame is implemented in the staggered SHC burner arrangement. The objective is to reach ultralow NOx emissions by complete evaporation and extensive premixing of fuel and air upstream of the lean reaction zone. In this work, a modeling approach is developed to investigate the characteristics of the lifted flame in an enclosed single-burner configuration, using the gaseous fuel methane. It is demonstrated that by using the large eddy simulation method, the shape and liftoff height of the flame are adequately reproduced by means of the finite-rate chemistry approach. For the numerical prediction of the lean lifted flame in the SHC arrangement, the focus is on the interaction of adjacent burners. It is shown that the swirling jet flow is deflected toward the sidewall of the staggered combustor dome, which is attributed to the asymmetrical confinement. Since the stabilization mechanism of the low-swirl flame relies on outer recirculation zones, the upstream transport of hot combustion products back to the flame base is studied by the variation of the combustor confinement ratio. It turns out that increasing the combustor size amplifies the exhaust gas recirculation along the sidewall, and increases the temperature of recirculating burned gases. This study emphasizes the capability of the proposed lean-burn combustor concept for future aero engine applications

    Foreign direct investment and the equity home bias puzzle

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    La extensa literatura macroeconómica que pretende explicar el ampliamente observado equity home bias ignora a las empresas internacionalmente activas. En un modelo DSGE que presenta la elección endógena de las empresas de ser activas internacionalmente —ya sea a través de las exportaciones o por medio de la inversión extranjera directa (IED)—, encontramos que las tenencias de capital óptimas de los agentes están sesgadas hacia las empresas nacionales. Nuestro hallazgo indica que la diversificación internacional no es tan negativa como sugieren las medidas empíricas del equity home bias.The vast macroeconomic literature trying to explain the widely observed equity home bias disregards internationally active firms. In a DSGE model that features the endogenous choice of firms to become internationally active through either exports or foreign direct investment (FDI), we find that the optimal equity holdings of agents are biased towards domestic firms. Our finding indicates that international diversification is not as bad as empirical measures of the equity home bias suggest

    Numerical Investigation of the Low-Swirl Flow in an Aeronautical Combustor With Angular Air Supply

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    Civil air traffic is predicted to further grow in the near future. Hence, the development of aeronautical combustors will face major challenges to meet future stringent environmental regulations. In the present study, an innovative gas turbine combustor with angular air supply called Short Helical Combustor (SHC) is investigated. The main feature of this concept is the helical arrangement of the fuel injectors around the turbine shaft. Aiming at the implementation of a lean-burn concept, a low-swirl lifted flame is adopted. This flame is lifted off and not anchored to the injector which opens the potential of low NOx emissions due to a high degree of premixing within the combustor. In this work, isothermal flow characteristics of such a generic SHC combustor are studied by use of RANS predictions with special emphasis on the interaction of adjacent low-swirl flows. For evaluating the influence of injector parameters on the flow field, a parametric study based on single sector simulations is performed. It is shown that the asymmetrically confined swirling jet flow is strongly deflected towards the sidewall of the staggered SHC dome. The deflection of the flow is associated with an asymmetric pressure field in the vicinity of the burner which is generally known as Coandă effect. As a consequence of the deflected flow, the angular momentum flux at combustor outlet is increased. The interaction of the low-swirl jet and the SHC sidewall is investigated with regards to backflow momentum and residence time in the recirculation zone. It is concluded that by modifying the momentum of the air flow through the injector, the amount of recirculating air flowing back along combustor walls is strongly affected. The present work establishes an understanding of the underlying aerodynamics of the SHC concept which is essential for matching the requirements of lean lifted flames

    Intake of 12 food groups and disability-adjusted life years from coronary heart disease, stroke, type 2 diabetes, and colorectal cancer in 16 European countries

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    Our aim was to estimate and rank 12 food groups according to disability-adjusted life years (DALYs) from coronary heart disease (CHD), stroke, type 2 diabetes (T2D), and colorectal cancer (CRC) in 16 European countries. De novo published non-linear dose–response meta-analyses of prospective studies (based on 297 primary reports), and food consumption data from the European Food Safety Authority Comprehensive European Food Consumption Database in Exposure Assessment, and DALY estimates from the Institute for Health Metrics and Evaluation were used. By implementing disease-specific counterfactual scenarios of theoretical minimum risk exposure level (TMRELs), the proportion of DALYs attributed to 12 food groups was estimated. In addition, a novel modelling approach was developed to obtain a single (optimized) TMREL across diseases. Four scenarios were analysed (A: disease-specific TMRELs/all food-disease associations; B: disease-specific TMRELs/only significant food-disease associations; C: single TMREL/all food-disease associations; D: single TMREL/only significant food-disease associations). Suboptimal food intake was associated with the following proportions of DALYs; Scenario A (highest-estimate) and D (lowest-estimate): CHD (A: 67%, D: 52%), stroke (A: 49%, D: 30%), T2D (A: 57%, D: 51%), and CRC (A: 54%, D: 40%). Whole grains (10%) had the highest impact on DALYs, followed by nuts (7.1%), processed meat (6.4%), fruit (4.4%) and fish and legumes (4.2%) when combining all scenarios. The contribution to total DALYs of all food groups combined in the different scenarios ranged from 41–52% in Austria to 51–69% in the Czech-Republic. These findings could have important implications for planning future food-based dietary guidelines as a public health nutrition strategy
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